["\u0111\u01b0\u1eddng kinh tuy\u1ebfn \u1edf c\u00e1c c\u1ef1c c\u00f3 ngh\u0129a l\u00e0 m\u1ed9t kinh \u0111\u1ed9 t\u1ea1i v\u00f9ng c\u1ef1c \u0111\u1ea1i di\u1ec7n cho ch\u1ec9 m\u1ed9t v\u00e0i d\u1eb7m v\u00e0 do \u0111\u00f3 c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c b\u1ecf qua. \u0110i\u1ec1u c\u1ed1t l\u00f5i l\u00e0 ph\u1ea3i gi\u1eef th\u1eb3ng h\u01b0\u1edbng \u0111i v\u1ec1 h\u01b0\u1edbng Nam. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n qua vi\u1ec7c \u0111o \u0111\u1ea1c v\u0129 \u0111\u1ed9 v\u1edbi k\u00ednh l\u1ee5c ph\u00e2n (d\u1ee5ng c\u1ee5 \u0111o \u0111\u1ed9 cao c\u1ee7a m\u1eb7t tr\u1eddi \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh v\u1ecb tr\u00ed con t\u00e0u..) v\u00e0 vi\u1ec7c s\u1eed d\u1ee5ng th\u1eadt kh\u00f4n ngoan chi\u1ebfc la b\u00e0n. Gi\u1ed1ng nh\u01b0 d\u00e2n chuy\u00ean nghi\u1ec7p, Amundsen ch\u1ea5p nh\u1eadn l\u1eddi khuy\u00ean c\u1ee7a Hinks, d\u00f9ng vi\u1ec7c \u0111\u1ecdc k\u00ednh l\u1ee5c ph\u00e2n v\u00e0 \u0111o\u00e1n m\u00f2 \u0111\u1ec3 ti\u1ebfn g\u1ea7n v\u1ec1 v\u00f9ng c\u1ef1c. Khi \u0111\u00e3 \u0111\u1ebfn \u0111\u00f3, \u00f4ng v\u00e0 \u0111\u1ed3ng \u0111\u1ed9i - t\u1ea5t c\u1ea3 bao g\u1ed3m b\u1ed1n th\u1ee7y th\u1ee7 l\u00e3o luy\u1ec7n - \u0111\u00e3 quan s\u00e1t th\u1eadt c\u1ea9n th\u1eadn v\u1edbi k\u00ednh l\u1ee5c ph\u00e2n v\u00e0 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c v\u1ecb tr\u00ed th\u1ef1c s\u1ef1 c\u1ee7a \u0111i\u1ec3m c\u1ef1c Nam l\u00e0 trong v\u00f2ng 250m. Sau \u0111\u00f3 h\u1ecd \u0111\u00e3 \u0111i lang thang qua l\u1ea1i tr\u00ean v\u00f9ng \u0111\u00f3 ba l\u1ea7n cho ch\u1eafc. C\u0169ng gi\u1ed1ng nh\u01b0 nhi\u1ec1u \u0111i\u1ec1u kh\u00e1c trong chuy\u1ebfn th\u00e1m hi\u1ec3m c\u1ee7a m\u00ecnh, Scott \u0111\u00e3 mang m\u1ed9t th\u00e1i \u0111\u1ed9 \u201cnghi\u1ec7p d\u01b0 - qu\u00fd ph\u00e1i\u201d khi ngh\u0129 v\u1ec1 chuy\u1ebfn h\u1ea3i tr\u00ecnh. \u00d4ng th\u1eadm ch\u00ed g\u1ea7n nh\u01b0 kh\u00f4ng b\u0103n kho\u0103n g\u00ec vi\u1ec7c c\u00f3 \u0111\u01b0\u1ee3c nh\u1eefng th\u1ee7y th\u1ee7 chuy\u00ean nghi\u1ec7p, nh\u01b0ng v\u00e0o ph\u00fat cu\u1ed1i \u00f4ng \u0111\u00e3 m\u1eddi m\u1ed9t s\u0129 quan \u1edf Petty l\u00e0 Henry Bowers gia nh\u1eadp \u0111\u1ed9i. Kh\u00f4ng bi\u1ebft g\u00ec v\u1ec1 l\u1eddi khuy\u00ean c\u1ee7a Hinks, Bowers \u0111\u00e3 s\u1eed d\u1ee5ng r\u1ea5t nhi\u1ec1u th\u1eddi gian trong cu\u1ed9c h\u00e0nh tr\u00ecnh v\u1ec1 v\u00f9ng c\u1ef1c \u0111\u1ec3 \u0111o \u0111\u1ea1c kinh v\u0129 \u0111\u1ed9 c\u00f9ng v\u1edbi nh\u1eefng t\u00ednh to\u00e1n ph\u1ee9c t\u1ea1p v\u00e0 d\u00e0i v\u00f4 t\u1eadn trong m\u1ed9t ho\u00e0n c\u1ea3nh h\u1ebft s\u1ee9c kh\u1eafc nghi\u1ec7t. Kh\u00f4ng c\u1ea7n ph\u1ea3i n\u00f3i, khi h\u1ecd s\u1eafp ho\u00e0n th\u00e0nh nh\u1eefng t\u00ednh to\u00e1n cu\u1ed1i c\u00f9ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh v\u1ecb tr\u00ed ch\u00ednh x\u00e1c c\u1ee7a \u0111i\u1ec3m c\u1ef1c Nam, Bowers v\u00e0 Scott \u0111\u00e3 ph\u1ea1m sai l\u1ea7m. Cho n\u00ean 50 https:\/\/thuviensach.vn","c\u0169ng kh\u00f4ng \u0111\u00fang l\u1eafm khi n\u00f3i r\u1eb1ng Scott v\u00e0 \u0111\u1ed3ng \u0111\u1ed9i \u0111\u00e3 t\u1edbi c\u1ef1c Nam ch\u1eadm h\u01a1n Amundsen m\u1ed9t th\u00e1ng: h\u1ecd th\u1ef1c t\u1ebf ch\u01b0a bao gi\u1edd t\u1edbi \u0111\u01b0\u1ee3c \u0111\u00f3 c\u1ea3. Li\u1ec7u cu\u1ed1i c\u00f9ng s\u1ef1 ph\u00e1 r\u1eebng 37 c\u00f3 khi\u1ebfn ch\u00fang ta c\u1ea1n ki\u1ec7t kh\u00ed oxy? Nh\u1eefng nh\u00e0 m\u00f4i tr\u01b0\u1eddng h\u1ecdc r\u1ea5t th\u00edch g\u1ecdi r\u1eebng c\u1ee7a th\u1ebf gi\u1edbi n\u00f3i chung v\u00e0 r\u1eebng Amazon n\u00f3i ri\u00eang l\u00e0 \u201cl\u00e1 ph\u1ed5i c\u1ee7a h\u00e0nh tinh\u201d, ng\u1ee5 \u00fd r\u1eb1ng n\u1ebfu ch\u00fang ta kh\u00f4ng ng\u1eebng vi\u1ec7c ph\u00e1 r\u1eebng ngay, t\u1ea5t c\u1ea3 ch\u00fang ta \u0111\u1ec1u s\u1eafp ph\u1ea3i th\u1edf h\u1ed5n h\u1ec3n. N\u0103m 2002, b\u1ed9 tr\u01b0\u1edfng m\u00f4i tr\u01b0\u1eddng c\u1ee7a Colombia \u0111\u00e3 ti\u1ebfn xa t\u1edbi m\u1ee9c ph\u1ea3i c\u1ea7u xin nh\u1eefng ng\u01b0\u1eddi s\u1eed d\u1ee5ng cocaine tr\u00ean th\u1ebf gi\u1edbi t\u1eeb b\u1ecf th\u00f3i quen c\u1ee7a h\u1ecd, b\u1edfi v\u00ec h\u1ecd \u0111ang khuy\u1ebfn kh\u00edch vi\u1ec7c t\u00e0n ph\u00e1 r\u1eebng m\u01b0a nhi\u1ec7t \u0111\u1edbi m\u00e0 \u201cth\u1ebf gi\u1edbi r\u1ea5t c\u1ea7n n\u00f3 cho ngu\u1ed3n oxy\u201d. Th\u1eadt may m\u1eafn (gi\u1ed1ng nh\u01b0 chuy\u1ec7n v\u1ec1 nh\u1eefng n\u1ed7i lo s\u1ee3 cho h\u1ec7 sinh th\u00e1i), kh\u00f4ng h\u1eb3n ph\u00e1 r\u1eebng l\u00e0 nguy\u00ean nh\u00e2n g\u00e2y c\u1ea1n ki\u1ec7t ngu\u1ed3n oxy c\u1ee7a ch\u00fang ta. Cho t\u1edbi gi\u1edd, th\u1ee9 \u0111\u00f3ng g\u00f3p l\u1edbn nh\u1ea5t cho ngu\u1ed3n oxy l\u1ea1i l\u00e0 m\u1ed9t lo\u00e0i t\u1ea3o \u0111\u00e1ng gh\u00e9t, d\u01a1 b\u1ea9n, tr\u00f4i n\u1ed5i nh\u01b0 nh\u1eefng v\u00e1ng b\u1ecdt m\u00e0u xanh tr\u00ean c\u00e1c \u0111\u1ea1i d\u01b0\u01a1ng c\u1ee7a th\u1ebf gi\u1edbi, ch\u00fang ch\u1ecbu tr\u00e1ch nhi\u1ec7m cho h\u01a1n 90% s\u1ea3n 51 https:\/\/thuviensach.vn","l\u01b0\u1ee3ng oxy. D\u0129 nhi\u00ean kh\u00f4ng n\u00ean ph\u00e1 r\u1eebng v\u00ec nhi\u1ec1u l\u00fd do nh\u01b0 ph\u00e1 r\u1eebng g\u00e2y n\u00ean l\u0169 l\u1ee5t, h\u1ea1n h\u00e1n, thay \u0111\u1ed5i sinh th\u00e1i, nh\u01b0ng n\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 l\u00fd do g\u00e2y ra vi\u1ec5n c\u1ea3nh \u00e1c m\u1ed9ng v\u1ec1 m\u1ed9t h\u00e0nh tinh b\u1ecb ng\u1ea1t th\u1edf. 38 C\u00f3 bao nhi\u00eau n\u01b0\u1edbc trong kh\u00ed quy\u1ec3n n\u1ebfu so s\u00e1nh v\u1edbi c\u00e1c \u0111\u1ea1i d\u01b0\u01a1ng? L\u01b0\u1ee3ng n\u01b0\u1edbc c\u00f3 trong kh\u00f4ng kh\u00ed hi\u1ec3n nhi\u00ean l\u00e0 thay \u0111\u1ed5i r\u1ea5t l\u1edbn t\u00f9y v\u00e0o th\u1eddi gian v\u00e0 \u0111\u1ecba \u0111i\u1ec3m m\u00e0 ng\u01b0\u1eddi ta \u0111o \u0111\u1ea1c, nh\u01b0ng m\u1ed9t con s\u1ed1 trung b\u00ecnh h\u1ee3p l\u00fd s\u1ebd v\u00e0o kho\u1ea3ng ba ph\u1ea7n n\u01b0\u1edbc trong m\u1ed9t ng\u00e0n ph\u1ea7n kh\u00f4ng kh\u00ed t\u00ednh theo kh\u1ed1i l\u01b0\u1ee3ng. V\u00ec kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a kh\u00ed quy\u1ec3n l\u00e0 kho\u1ea3ng 5 tri\u1ec7u t\u1ec9 t\u1ea5n, ngh\u0129a l\u00e0 c\u00f3 kho\u1ea3ng 15 tri\u1ec7u tri\u1ec7u t\u1ea5n n\u01b0\u1edbc trong kh\u00f4ng kh\u00ed - nghe c\u00f3 v\u1ebb r\u1ea5t nhi\u1ec1u, nh\u01b0ng ch\u1eb3ng \u0111\u00e1ng l\u00e0 bao khi so v\u1edbi n\u01b0\u1edbc trong c\u00e1c \u0111\u1ea1i d\u01b0\u01a1ng, v\u00ec n\u01b0\u1edbc trong \u0111\u1ea1i d\u01b0\u01a1ng c\u00f2n nhi\u1ec1u g\u1ea5p kho\u1ea3ng 100.000 l\u1ea7n. 39 T\u1ea1i sao s\u1ef1 n\u00f3ng l\u00ean to\u00e0n c\u1ea7u l\u1ea1i l\u00e0m d\u00e2ng m\u1ef1c n\u01b0\u1edbc bi\u1ec3n? \u0110\u00e2y c\u00f3 v\u1ebb nh\u01b0 l\u00e0 m\u1ed9t l\u1eddi tuy\u00ean b\u1ed1 r\u1ea5t k\u00ec l\u1ea1, v\u00ec nh\u01b0 m\u1ecdi ng\u01b0\u1eddi \u0111\u1ec1u bi\u1ebft, n\u01b0\u1edbc \u0111\u00e1 chi\u1ebfm nhi\u1ec1u th\u1ec3 t\u00edch h\u01a1n 52 https:\/\/thuviensach.vn","so v\u1edbi m\u1ed9t kh\u1ed1i l\u01b0\u1ee3ng n\u01b0\u1edbc t\u01b0\u01a1ng \u0111\u01b0\u01a1ng (\u0111\u00f3 l\u00e0 l\u00fd do v\u00ec sao n\u00f3 c\u00f3 th\u1ec3 n\u1ed5i). V\u00ec v\u1eady, c\u00f3 th\u1ec3 b\u1ea1n cho r\u1eb1ng, n\u1ebfu kh\u1ed1i b\u0103ng tr\u00f4i B\u1eafc c\u1ef1c \u0111\u01b0\u1ee3c nghi\u00ean c\u1ee9u r\u1ea5t nhi\u1ec1u kia tan ra th\u00ec m\u1ef1c n\u01b0\u1edbc bi\u1ec3n s\u1ebd th\u1ea5p h\u01a1n m\u1ed9t ch\u00fat. Th\u1ef1c t\u1ebf s\u1ebd kh\u00f4ng nh\u01b0 v\u1eady, b\u1edfi v\u00ec kh\u00f4ng ph\u1ea3i t\u1ea5t c\u1ea3 ph\u1ea7n th\u1ec3 t\u00edch tr\u1ed9i h\u01a1n c\u1ee7a n\u01b0\u1edbc \u0111\u00e1 \u0111\u1ec1u th\u1ef1c s\u1ef1 b\u1ecb nh\u1ea5n ch\u00ecm: m\u1ed9t ph\u1ea7n c\u1ee7a n\u00f3 s\u1ebd n\u1eb1m b\u00ean tr\u00ean m\u1eb7t n\u01b0\u1edbc. Khi n\u01b0\u1edbc \u0111\u00e1 tan ra, s\u1ef1 kh\u00e1c bi\u1ec7t t\u1ec9 tr\u1ecdng s\u1ebd bi\u1ebfn m\u1ea5t, k\u1ebft qu\u1ea3 l\u00e0 ph\u1ea7n n\u01b0\u1edbc \u0111\u00e1 b\u1ecb tan ra l\u1ea1i chi\u1ebfm l\u1ea5y \u0111\u00fang ph\u1ea7n th\u1ec3 t\u00edch n\u01b0\u1edbc bi\u1ec3n ban \u0111\u1ea7u b\u1ecb chi\u1ebfm ch\u1ed7. Th\u1ebf l\u00e0: m\u1ef1c n\u01b0\u1edbc bi\u1ec3n kh\u00f4ng thay \u0111\u1ed5i. Tuy nhi\u00ean, \u0111i\u1ec1u \u0111\u00f3 l\u1ea1i kh\u00f4ng \u0111\u00fang cho b\u0103ng tuy\u1ebft \u1edf Nam c\u1ef1c v\u00e0 \u1edf c\u00e1c s\u00f4ng b\u0103ng tr\u00ean kh\u1eafp th\u1ebf gi\u1edbi, b\u1edfi v\u00ec ch\u00fang hi\u1ec7n \u0111ang n\u1eb1m tr\u00ean m\u1eb7t \u0111\u1ea5t li\u1ec1n v\u00e0 do \u0111\u00f3 kh\u00f4ng g\u00f3p ph\u1ea7n t\u1ea1o n\u00ean m\u1ef1c n\u01b0\u1edbc bi\u1ec3n. Khi b\u0103ng tuy\u1ebft \u1edf \u0111\u00e2y tan ra, ch\u00fang s\u1ebd ch\u1ea3y xu\u1ed1ng bi\u1ec3n v\u00e0 l\u00e0m d\u00e2ng m\u1ef1c n\u01b0\u1edbc bi\u1ec3n. S\u1ef1 gi\u00e3n n\u1edf v\u00ec nhi\u1ec7t c\u1ee7a n\u01b0\u1edbc bi\u1ec3n, k\u1ebft h\u1ee3p v\u1edbi c\u00e1c \u0111i\u1ec1u ki\u1ec7n kh\u00e1c, c\u0169ng l\u00e0 nguy\u00ean nh\u00e2n l\u00e0m m\u1ef1c n\u01b0\u1edbc bi\u1ec3n d\u00e2ng cao khi tr\u00e1i \u0111\u1ea5t n\u00f3ng l\u00ean. Li\u1ec7u s\u1ef1 n\u00f3ng l\u00ean to\u00e0n c\u1ea7u 40 c\u00f3 l\u00e0m cho d\u00f2ng h\u1ea3i l\u01b0u Gulf Stream bi\u1ebfn m\u1ea5t? \u0110i\u1ec1u ph\u1ea3i lo l\u1eafng l\u00e0 khi tr\u00e1i \u0111\u1ea5t n\u00f3ng l\u00ean qu\u00e1 nhi\u1ec1u v\u00e0 b\u0103ng B\u1eafc c\u1ef1c tan ch\u1ea3y, t\u1ea1o th\u00e0nh n\u01b0\u1edbc ng\u1ecdt c\u00f3 t\u1ec9 53 https:\/\/thuviensach.vn","tr\u1ecdng th\u1ea5p h\u01a1n n\u01b0\u1edbc bi\u1ec3n - s\u1ebd g\u00e2y ra s\u1ef1 \u0111\u1ee9t \u0111o\u1ea1n trong l\u01b0u th\u00f4ng c\u1ee7a d\u00f2ng h\u1ea3i l\u01b0u \u1ea5m Gulf Stream. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn s\u1ef1 t\u1ee5t gi\u1ea3m nhi\u1ec7t \u0111\u1ed9 c\u1ee7a v\u01b0\u01a1ng qu\u1ed1c Anh t\u1edbi m\u1ed9t m\u1ee9c ch\u01b0a t\u1eebng th\u1ea5y k\u1ec3 t\u1eeb l\u1ea7n cu\u1ed1i c\u00f9ng n\u00f3 xu\u1ea5t hi\u1ec7n c\u00e1ch \u0111\u00e2y kho\u1ea3ng 17.500 n\u0103m. N\u0103m 1999, c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u1edf Ph\u00f2ng th\u00ed nghi\u1ec7m h\u1ea3i d\u01b0\u01a1ng h\u1ecdc Scottland, Aberdeen, \u0111\u00e3 ph\u00e2n t\u00edch n\u1ed3ng \u0111\u1ed9 mu\u1ed1i trong n\u01b0\u1edbc bi\u1ec3n n\u1eb1m gi\u1eefa Shetland v\u00e0 Faroe Islands \u0111\u01b0\u1ee3c thu th\u1eadp t\u1eeb 1893; c\u00e1c k\u1ebft qu\u1ea3 cho th\u1ea5y m\u1ed9t s\u1ef1 s\u1ee5t gi\u1ea3m r\u00f5 r\u00e0ng c\u1ee7a n\u1ed3ng \u0111\u1ed9 mu\u1ed1i trong 20 n\u0103m v\u1eeba qua so v\u1edbi th\u1ebf k\u1ef7 tr\u01b0\u1edbc. Hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y r\u1ea5t ph\u00f9 h\u1ee3p v\u1edbi s\u1ef1 gia t\u0103ng c\u1ee7a m\u1ee9c n\u01b0\u1edbc ng\u1ecdt \u0111\u1ed5 v\u00e0o bi\u1ec3n t\u1eeb B\u1eafc c\u1ef1c. L\u01b0\u1ee3ng n\u01b0\u1edbc n\u00e0y c\u00f3 v\u1ebb c\u0169ng \u0111\u00e3 l\u00e0m gi\u1ea3m s\u1ee9c ch\u1ea3y c\u1ee7a d\u00f2ng n\u01b0\u1edbc \u1ea5m \u0111i kho\u1ea3ng 20% trong 50 n\u0103m v\u1eeba qua. Tuy v\u1eady, c\u0169ng nh\u01b0 m\u1ecdi nghi\u00ean c\u1ee9u kh\u00ed h\u1eadu kh\u00e1c, th\u1eadt kh\u00f3 \u0111\u1ec3 n\u00f3i li\u1ec7u \u0111\u00e2y ch\u1ec9 l\u00e0 bi\u1ebfn \u0111\u1ed9ng nh\u1ecf hay l\u00e0 bi\u1ec3u hi\u1ec7n c\u1ee7a m\u1ed9t xu h\u01b0\u1edbng th\u1eadt s\u1ef1. N\u1ebfu c\u00f3 th\u1ec3 ch\u1ee9ng minh \u0111\u00f3 l\u00e0 m\u1ed9t xu h\u01b0\u1edbng th\u1eadt s\u1ef1, m\u1ed9t v\u00e0i nh\u00e0 khoa h\u1ecdc s\u1ebd tuy\u00ean b\u1ed1 r\u1eb1ng c\u00e1c t\u00e1c \u0111\u1ed9ng n\u00e0y s\u1ebd \u0111\u01b0\u1ee3c nh\u1eadn th\u1ea5y s\u1edbm h\u01a1n ch\u00fang ta ngh\u0129. T\u00ednh to\u00e1n tr\u00ean m\u00e1y vi t\u00ednh v\u00e0 nghi\u00ean c\u1ee9u c\u00e1c l\u00f5i b\u0103ng g\u1ee3i \u00fd r\u1eb1ng c\u00e1c d\u00f2ng h\u1ea3i l\u01b0u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c m\u1edf v\u00e0 \u0111\u00f3ng l\u1ea1i nhanh \u0111\u1ebfn b\u1ea5t ng\u1edd, g\u00e2y ra nh\u1eefng thay \u0111\u1ed5i nhi\u1ec7t \u0111\u1ed9 nghi\u00eam tr\u1ecdng ch\u1ec9 trong kho\u1ea3ng m\u1ed9t th\u1eadp ni\u00ean - m\u1ed9t c\u00e1i nh\u00e1y m\u1eaft trong quan \u0111i\u1ec3m \u0111\u1ecba ch\u1ea5t h\u1ecdc. 54 https:\/\/thuviensach.vn","41 Tr\u00e1i \u0111\u1ea5t c\u00e1ch xa m\u1eb7t tr\u1eddi nh\u1ea5t v\u00e0o th\u00e1ng 7, v\u1eady t\u1ea1i sao \u0111\u00e2y l\u1ea1i l\u00e0 th\u00e1ng n\u00f3ng nh\u1ea5t trong n\u0103m \u1edf b\u1eafc b\u00e1n c\u1ea7u? Ch\u1eafc ch\u1eafn l\u00e0 tr\u00e1i \u0111\u1ea5t c\u00e1ch xa m\u1eb7t tr\u1eddi nh\u1ea5t v\u00e0o kho\u1ea3ng th\u00e1ng 7 - xa h\u01a1n kho\u1ea3ng g\u1ea7n 4 tri\u1ec7u km so v\u1edbi th\u00e1ng gi\u00eang - v\u00e0 \u0111i\u1ec1u \u0111\u00f3 c\u00f3 ngh\u0129a l\u00e0 nhi\u1ec7t l\u01b0\u1ee3ng m\u00e0 tr\u00e1i \u0111\u1ea5t nh\u1eadn \u0111\u01b0\u1ee3c t\u1eeb m\u1eb7t tr\u1eddi s\u1ebd \u00edt \u0111i kho\u1ea3ng 6%. R\u00f5 r\u00e0ng l\u00e0 kho\u1ea3ng c\u00e1ch t\u1eeb tr\u00e1i \u0111\u1ea5t t\u1edbi m\u1eb7t tr\u1eddi kh\u00f4ng ph\u1ea3i l\u00e0 l\u00fd do t\u1ea1i sao th\u00e1ng n\u00f3ng nh\u1ea5t l\u1ea1i v\u00e0o th\u1eddi gian \u0111\u00f3: v\u00ec n\u1ebfu l\u00fd do \u0111\u00fang nh\u01b0 v\u1eady, t\u1ea5t c\u1ea3 c\u00e1c n\u01a1i tr\u00ean h\u00e0nh tinh s\u1ebd v\u00e0o m\u00f9a h\u00e8 c\u00f9ng m\u1ed9t l\u00fac. Nguy\u00ean nh\u00e2n ch\u1ee7 y\u1ebfu do h\u00e0nh tinh ch\u00fang ta b\u1ecb ng- hi\u00eang \u0111i kho\u1ea3ng 230 so v\u1edbi tr\u1ee5c th\u1eb3ng \u0111\u1ee9ng. Trong su\u1ed1t m\u00f9a h\u00e8 c\u1ee7a b\u1eafc b\u00e1n c\u1ea7u, tr\u00e1i \u0111\u1ea5t b\u1ecb nghi\u00eang v\u1ec1 ph\u00eda m\u1eb7t tr\u1eddi, l\u00e0m cho tia s\u00e1ng m\u1eb7t tr\u1eddi chi\u1ebfu xu\u1ed1ng t\u01b0\u01a1ng \u0111\u1ed1i th\u1eb3ng g\u00f3c, v\u00ec v\u1eady hi\u1ec7u \u1ee9ng nhi\u1ec7t c\u1ee7a n\u00f3 tr\u00ean m\u1ed7i m\u00e9t vu\u00f4ng l\u00e0 t\u01b0\u01a1ng \u0111\u1ed1i cao. Tuy nhi\u00ean, trong su\u1ed1t m\u00f9a \u0111\u00f4ng c\u1ee7a b\u1eafc b\u00e1n c\u1ea7u, n\u00f3 b\u1ecb nghi\u00eang ra xa m\u1eb7t tr\u1eddi, l\u00e0m cho tia s\u00e1ng m\u1eb7t tr\u1eddi chi\u1ebfu xu\u1ed1ng v\u1edbi g\u00f3c nh\u1ecf h\u01a1n, v\u00ec v\u1eady l\u00e0m gi\u1ea3m l\u01b0\u1ee3ng nhi\u1ec7t tr\u00ean m\u1ed7i m\u00e9t vu\u00f4ng. \u0110\u01b0\u01a1ng nhi\u00ean, 55 https:\/\/thuviensach.vn","c\u00e0ng \u0111i xu\u1ed1ng d\u01b0\u1edbi, s\u1ebd c\u00f3 hi\u1ec7n t\u01b0\u1ee3ng ng\u01b0\u1ee3c l\u1ea1i. V\u1eady nh\u00ecn chung, \u1edf c\u00e1c v\u0129 tuy\u1ebfn b\u1eafc, ng\u00e0y n\u00f3ng nh\u1ea5t trong n\u0103m s\u1ebd l\u00e0 ng\u00e0y h\u1ea1 ch\u00ed, 23 th\u00e1ng 6. Th\u1ef1c t\u1ebf, \u1edf Anh, n\u01a1i m\u00e0 m\u1ed9t ph\u1ea7n l\u1edbn nhi\u1ec7t l\u01b0\u1ee3ng \u0111\u1ebfn t\u1eeb c\u00e1c d\u00f2ng h\u1ea3i l\u01b0u \u1ea5m, c\u1ea7n ph\u1ea3i c\u00f3 m\u1ed9t th\u1eddi gian \u0111\u1ec3 c\u00e1c d\u00f2ng h\u1ea3i l\u01b0u b\u1eaft k\u1ecbp nhi\u1ec7t \u0111\u1ed9 b\u00ean tr\u00ean v\u00e0 do \u0111\u00f3 \u00edt nh\u1ea5t c\u0169ng ph\u1ea3i \u0111\u1ebfn th\u00e1ng 7 th\u00ec v\u01b0\u01a1ng qu\u1ed1c Anh m\u1edbi b\u1eaft \u0111\u1ea7u th\u1ea5y \u1ea5m h\u01a1n. 42 T\u1ea1i sao m\u1eb7t tr\u1eddi v\u1eabn m\u1ecdc tr\u1ec5 h\u01a1n v\u00e0o bu\u1ed5i s\u00e1ng sau ng\u00e0y ng\u1eafn nh\u1ea5t trong n\u0103m? \u0110\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 \u0111i\u1ec1u g\u00e2y t\u00f2 m\u00f2 duy nh\u1ea5t v\u1ec1 ho\u1ea1t \u0111\u1ed9ng c\u1ee7a m\u1eb7t tr\u1eddi trong m\u00f9a \u0111\u00f4ng: ng\u00e0y m\u1eb7t tr\u1eddi l\u1eb7n s\u1edbm nh\u1ea5t kh\u00f4ng tr\u00f9ng v\u1edbi ng\u00e0y ng\u1eafn nh\u1ea5t m\u00e0 l\u1ea1i x\u1ea3y ra s\u1edbm h\u01a1n m\u1ed9t tu\u1ea7n. T\u1ea5t c\u1ea3 nh\u1eefng s\u1ef1 b\u1ea5t th\u01b0\u1eddng n\u00e0y \u0111\u1ec1u l\u00e0 k\u1ebft qu\u1ea3 c\u1ee7a hai \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a h\u00e0nh tinh ch\u00fang ta: th\u1ee9 nh\u1ea5t, qu\u1ef9 \u0111\u1ea1o c\u1ee7a n\u00f3 quanh m\u1eb7t tr\u1eddi kh\u00f4ng tr\u00f2n ho\u00e0n h\u1ea3o v\u00e0 th\u1ee9 hai, tr\u1ee5c xoay c\u1ee7a n\u00f3 c\u0169ng kh\u00f4ng vu\u00f4ng g\u00f3c ho\u00e0n h\u1ea3o v\u1edbi m\u1eb7t ph\u1eb3ng qu\u1ef9 \u0111\u1ea1o c\u1ee7a n\u00f3. T\u00e1c \u0111\u1ed9ng k\u1ebft h\u1ee3p ch\u00ednh l\u00e0 s\u1ef1 thay \u0111\u1ed5i t\u1ed1c \u0111\u1ed9 ho\u00e0n th\u00e0nh h\u00e0nh tr\u00ecnh h\u00e0ng ng\u00e0y c\u1ee7a m\u1eb7t tr\u1eddi t\u1eeb \u0110\u00f4ng sang T\u00e2y t\u00f9y theo th\u1eddi \u0111i\u1ec3m trong n\u0103m. 56 https:\/\/thuviensach.vn","Trong nh\u1eefng th\u00e1ng m\u00f9a \u0111\u00f4ng, \u1edf nh\u1eefng v\u0129 tuy\u1ebfn b\u1eafc, qu\u1ef9 \u0111\u1ea1o l\u1ec7ch t\u00e2m c\u1ee7a tr\u00e1i \u0111\u1ea5t mang n\u00f3 \u0111\u1ebfn g\u1ea7n m\u1eb7t tr\u1eddi nh\u1ea5t (\u0111i\u1ec3m c\u1eadn nh\u1eadt) v\u00e0o kho\u1ea3ng ng\u00e0y 4 th\u00e1ng gi\u00eang, \u0111\u00f3 c\u0169ng l\u00e0 \u0111i\u1ec3m m\u00e0 n\u00f3 di chuy\u1ec3n nhanh nh\u1ea5t trong kh\u00f4ng gian. \u0110\u1ebfn l\u00fac n\u00e0y, g\u00f3c nghi\u00eang c\u1ee7a tr\u00e1i \u0111\u1ea5t c\u0169ng t\u00e1c \u0111\u1ed9ng v\u00e0o hi\u1ec7u \u1ee9ng tr\u00ean, v\u00e0 m\u1eb7t tr\u1eddi b\u1eaft \u0111\u1ea7u l\u00f9i v\u1ec1 h\u01b0\u1edbng b\u1eafc m\u1ed9t l\u1ea7n n\u1eefa v\u00e0o m\u00f9a h\u00e8. Do \u0111\u00f3, ng\u01b0\u1ee3c v\u1edbi nh\u1eefng g\u00ec ta th\u1ea5y, m\u1eb7t tr\u1eddi kh\u00f4ng \u0111i ngang qua b\u1ea7u tr\u1eddi v\u1edbi c\u00f9ng m\u1ed9t nh\u1ecbp \u0111\u1ed9 trong su\u1ed1t n\u0103m m\u00e0 l\u1ea1i t\u0103ng t\u1ed1c r\u1ed3i ch\u1eadm l\u1ea1i t\u00f9y theo s\u1ef1 k\u1ebft h\u1ee3p l\u1ed9n x\u1ed9n c\u1ee7a hai hi\u1ec7u \u1ee9ng n\u00e0y. \u0110i\u1ec1u \u0111\u00f3, do v\u1eady khi\u1ebfn cho m\u1eb7t tr\u1eddi kh\u00f4ng th\u1ec3 l\u00e0 m\u1ed9t \u0111\u1ed3ng h\u1ed3 l\u00fd t\u01b0\u1edfng; \u0111\u1ec3 v\u01b0\u1ee3t qua s\u1ef1 khi\u1ebfm khuy\u1ebft n\u00e0y, c\u00e1c nh\u00e0 thi\u00ean v\u0103n h\u1ecdc th\u1eddi Victoria \u0111\u00e3 ph\u00e1t minh ra m\u1ed9t phi\u00ean b\u1ea3n m\u1eb7t tr\u1eddi gi\u1ea3 m\u00e0 h\u1ecd c\u00f3 th\u1ec3 d\u1ef1a v\u00e0o, g\u1ecdi l\u00e0 M\u1eb7t tr\u1eddi Trung b\u00ecnh (Mean Sun), v\u1edbi t\u1ed1c \u0111\u1ed9 \u0111i ngang qua b\u1ea7u tr\u1eddi l\u00e0 h\u1eb1ng s\u1ed1. M\u1eb7t tr\u1eddi nh\u00e2n t\u1ea1o n\u00e0y c\u0169ng l\u00e0 c\u01a1 s\u1edf c\u1ee7a m\u00fai gi\u1edd g\u1ed1c Greenwich (Greenwich Mean Time, GMT) - gi\u1edd \u1edf \u0111\u00e2y ph\u1ee5 thu\u1ed9c v\u00e0o s\u1ef1 di chuy\u1ec3n c\u1ee7a M\u1eb7t tr\u1eddi Trung b\u00ecnh qua kinh tuy\u1ebfn Greenwich - v\u00e0 m\u00fai gi\u1edd n\u00e0y c\u0169ng \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh th\u1eddi \u0111i\u1ec3m m\u1eb7t tr\u1eddi m\u1ecdc v\u00e0 l\u1eb7n. M\u1ed9t h\u1eadu qu\u1ea3 c\u1ee7a vi\u1ec7c c\u1ed1 g\u1eafng \u00e1p \u0111\u1eb7t quy lu\u1eadt cho th\u1ebf gi\u1edbi t\u1ef1 nhi\u00ean n\u00e0y l\u00e0: s\u1ef1 kh\u00e1c nhau gi\u1eefa gi\u1edd GMT v\u1edbi nh\u1eefng chuy\u1ec3n \u0111\u1ed9ng th\u1ef1c s\u1ef1 c\u1ee7a m\u1eb7t tr\u1eddi. \u0110i\u1ec1u n\u00e0y \u0111\u01b0\u1ee3c bi\u1ec3u hi\u1ec7n ra th\u00e0nh s\u1ef1 kh\u00f4ng t\u01b0\u01a1ng \u1ee9ng gi\u1eefa nh\u1eefng ng\u00e0y m\u1eb7t tr\u1eddi m\u1ecdc tr\u1ec5 nh\u1ea5t v\u00e0 l\u1eb7n s\u1edbm nh\u1ea5t v\u1edbi ng\u00e0y ng\u1eafn nh\u1ea5t. 57 https:\/\/thuviensach.vn","43 Li\u1ec7u c\u00e1c t\u1ea3ng b\u0103ng tr\u00f4i \u1edf Nam c\u1ef1c c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c k\u00e9o v\u1ec1 nh\u1eefng mi\u1ec1n \u0111\u1ea5t kh\u00f4 c\u1eb1n? Nh\u1eefng t\u1ea3ng b\u0103ng \u1edf Nam c\u1ef1c chi\u1ebfm kho\u1ea3ng 70% l\u01b0\u1ee3ng n\u01b0\u1edbc ng\u1ecdt c\u1ee7a th\u1ebf gi\u1edbi, v\u00e0 v\u00ec 1,2 t\u1ec9 ng\u01b0\u1eddi kh\u00f4ng d\u1ec5 d\u00e0ng ti\u1ebfp c\u1eadn v\u1edbi ngu\u1ed3n n\u01b0\u1edbc u\u1ed1ng \u0111\u01b0\u1ee3c, \u00fd t\u01b0\u1edfng mang b\u0103ng v\u1ec1 t\u1eeb Nam c\u1ef1c \u0111\u00e3 \u0111\u01b0\u1ee3c nh\u1eafc l\u1ea1i nhi\u1ec1u l\u1ea7n t\u1eeb khi n\u00f3 \u0111\u01b0\u1ee3c n\u00eau ra l\u1ea7n \u0111\u1ea7u ti\u00ean c\u00e1ch \u0111\u00e2y 50 n\u0103m b\u1edfi ti\u1ebfn s\u0129 John Isaacs c\u1ee7a vi\u1ec7n H\u1ea3i d\u01b0\u01a1ng h\u1ecdc Scripps \u1edf California. V\u00e0o cu\u1ed1i nh\u1eefng n\u0103m 1970, m\u1ed9t trong nh\u1eefng ng\u01b0\u1eddi con trai c\u1ee7a vua Faisal c\u1ee7a \u1ea2 R\u1eadp Saudi th\u1eadm ch\u00ed c\u00f2n l\u1eadp n\u00ean m\u1ed9t c\u00f4ng ty \u0111\u1ec3 nghi\u00ean c\u1ee9u \u00fd t\u01b0\u1edfng n\u00e0y. \u00dd t\u01b0\u1edfng n\u00e0y kh\u00f4ng th\u1ef1c s\u1ef1 g\u00e0n d\u1edf nh\u01b0 ta t\u01b0\u1edfng, \u00edt nh\u1ea5t l\u00e0 v\u1ec1 m\u1eb7t k\u1ef9 thu\u1eadt. Nh\u1eefng ng\u01b0\u1eddi ph\u1ea3n \u0111\u1ed1i t\u1ee9c th\u00ec - r\u1eb1ng b\u0103ng s\u1ebd tan ra tr\u01b0\u1edbc khi t\u1edbi \u0111\u00edch - \u0111\u00e3 kh\u00f4ng th\u1ea5y \u0111\u01b0\u1ee3c m\u1ed9t l\u01b0\u1ee3ng nhi\u1ec7t l\u1edbn kh\u00e1c th\u01b0\u1eddng c\u1ea7n thi\u1ebft \u0111\u1ec3 chuy\u1ec3n b\u0103ng th\u00e0nh n\u01b0\u1edbc. R\u1ea5t c\u00f3 th\u1ec3 r\u1eb1ng ch\u1ec9 m\u1ed9t t\u1ec9 l\u1ec7 nh\u1ecf b\u0103ng b\u1ecb tan ra trong chuy\u1ebfn h\u00e0nh tr\u00ecnh t\u1eeb Nam c\u1ef1c c\u1ee7a n\u00f3. Nh\u1eefng chi\u1ebfc t\u00e0u \u0111\u1ee7 m\u1ea1nh \u0111\u1ec3 k\u00e9o m\u1ed9t t\u1ea3ng b\u0103ng c\u00f3 k\u00edch th\u01b0\u1edbc v\u1eeba ph\u1ea3i, n\u1eb7ng 100 tri\u1ec7u t\u1ea5n, \u0111\u00e3 xu\u1ea5t hi\u1ec7n v\u00e0 nh\u1eefng s\u1ee3i c\u00e1p \u0111\u1ee7 ch\u1eafc \u0111\u1ec3 k\u00e9o t\u1ea3ng b\u0103ng c\u0169ng c\u00f3 th\u1ec3 ch\u1ebf t\u1ea1o \u0111\u01b0\u1ee3c. Th\u1eadt h\u00e0i h\u01b0\u1edbc r\u1eb1ng v\u1ea5n \u0111\u1ec1 th\u1eadt s\u1ef1 kh\u00f3 kh\u0103n l\u1ea1i l\u00e0 l\u00e0m tan n\u00f3 58 https:\/\/thuviensach.vn","ra khi n\u00f3 \u0111\u00e3 t\u1edbi n\u01a1i - \u0111\u1ec3 cung c\u1ea5p \u0111\u01b0\u1ee3c cho d\u00e2n ch\u00fang m\u1ed9t l\u01b0\u1ee3ng n\u01b0\u1edbc h\u1ee3p l\u00fd s\u1ebd ph\u1ea3i c\u1ea7n \u0111\u1ebfn c\u00f4ng su\u1ea5t c\u1ee7a m\u1ed9t nh\u00e0 m\u00e1y \u0111i\u1ec7n l\u1edbn. Th\u00eam v\u00e0o chi ph\u00ed l\u1edbn c\u1ee7a vi\u1ec7c ph\u00e2n ph\u1ed1i n\u01b0\u1edbc t\u1edbi n\u01a1i c\u1ea7n thi\u1ebft nh\u1ea5t - th\u01b0\u1eddng l\u00e0 xa b\u1edd bi\u1ec3n - l\u00e0 chi ph\u00ed \u0111\u1ec3 k\u00e9o b\u0103ng \u0111i h\u00e0ng ng\u00e0n d\u1eb7m t\u1eeb Nam c\u1ef1c. S\u1ef1 ph\u1ea3n \u0111\u1ed1i ch\u1ee7 y\u1ebfu r\u00f5 r\u00e0ng l\u00e0 n\u1eb1m \u1edf hi\u1ec7u qu\u1ea3 kinh t\u1ebf. Th\u1ebf n\u00ean hi\u1ec7n nay, vi\u1ec7c k\u00e9o b\u0103ng v\u1eabn c\u00f2n l\u00e0 m\u1ed9t gi\u1ea5c m\u1ed9ng vi\u1ec5n v\u00f4ng c\u1ee7a c\u00e1c k\u1ef9 s\u01b0 \u0111\u01b0\u1eddng \u1ed1ng. 44 \u0110\u1ed9ng \u0111\u1ea5t \u0111\u00e3 bao gi\u1edd \u0111\u01b0\u1ee3c d\u1ef1 \u0111o\u00e1n th\u00e0nh c\u00f4ng ch\u01b0a? Th\u00e1ng 2 n\u0103m 1975, c\u00e1c nh\u00e0 \u0111\u1ecba ch\u1ea5n h\u1ecdc Trung Qu\u1ed1c, sau khi ph\u00e1t hi\u1ec7n m\u1ed9t lo\u1ea1t c\u00e1c ch\u1ea5n \u0111\u1ed9ng truy\u1ec1n qua t\u1ec9nh Haicheng, \u0111\u00e3 \u0111\u01b0a ra l\u1eddi c\u1ea3nh b\u00e1o r\u1eb1ng m\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t l\u1edbn s\u1eafp n\u1ed5 ra \u1edf Manchuria. C\u00e1c cu\u1ed9c di t\u1ea3n \u0111\u00e3 \u0111\u01b0\u1ee3c ti\u1ebfn h\u00e0nh v\u00e0 h\u00e0ng ng\u00e0n m\u1ea1ng ng\u01b0\u1eddi \u0111\u00e3 \u0111\u01b0\u1ee3c c\u1ee9u s\u1ed1ng trong tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t c\u01b0\u1eddng \u0111\u1ed9 7,3 \u0111\u1ed9 Richter \u0111\u00e3 x\u1ea3y ra trong v\u00f2ng 24 gi\u1edd sau \u0111\u00f3. Th\u1ebf nh\u01b0ng th\u00e0nh c\u00f4ng trong vi\u1ec7c d\u1ef1 b\u00e1o \u0111\u1ed9ng \u0111\u1ea5t n\u00e0y \u0111\u00e3 \u00edt \u0111\u01b0\u1ee3c ch\u00fa \u00fd. Sau n\u00e0y ng\u01b0\u1eddi ta bi\u1ebft \u0111\u01b0\u1ee3c r\u1eb1ng c\u0169ng nh\u00f3m nh\u00e0 khoa h\u1ecdc \u0111\u00f3 \u0111\u00e3 cho ra m\u1ed9t l\u1eddi ti\u00ean \u0111o\u00e1n t\u01b0\u01a1ng t\u1ef1 v\u00e0o n\u0103m tr\u01b0\u1edbc, nh\u01b0ng sau c\u00f9ng l\u1ea1i l\u00e0 m\u1ed9t b\u00e1o \u0111\u1ed9ng sai. Sau n\u00e0y m\u1ed9t n\u0103m, nh\u00f3m n\u00e0y l\u1ea1i th\u1ea5t b\u1ea1i trong vi\u1ec7c d\u1ef1 \u0111o\u00e1n tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t Tangshan, tr\u1eadn kh\u1ee7ng khi\u1ebfp nh\u1ea5t c\u1ee7a th\u1ebf k\u1ef7 20, \u0111\u1ec3 l\u1ea1i \u00edt nh\u1ea5t l\u00e0 240 ng\u00e0n ng\u01b0\u1eddi thi\u1ec7t m\u1ea1ng. 59 https:\/\/thuviensach.vn","\u0110i\u1ec1u n\u00e0y c\u0169ng kh\u00f4ng l\u00e0m nh\u1ee5t ch\u00ed nh\u1eefng ng\u01b0\u1eddi kh\u00e1c tuy\u00ean b\u1ed1 r\u1eb1ng \u0111\u00e3 ph\u00e1 \u0111\u01b0\u1ee3c c\u00e2u \u0111\u1ed1 v\u1ec1 d\u1ef1 \u0111o\u00e1n \u0111\u1ed9ng \u0111\u1ea5t b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng nh\u1eefng c\u00f4ng th\u1ee9c b\u00ed m\u1eadt c\u1ee7a ri\u00eang h\u1ecd. N\u0103m 1977, m\u1ed9t nh\u00f3m c\u00e1c nh\u00e0 \u0111\u1ecba ch\u1ea5n h\u1ecdc li\u00ean qu\u1ed1c gia \u0111\u00e3 quy\u1ebft \u0111\u1ecbnh r\u1eb1ng s\u1ef1 s\u1ee5t gi\u1ea3m ho\u1ea1t \u0111\u1ed9ng \u0111\u1ed9ng \u0111\u1ea5t g\u1ea7n Oaxaca \u1edf Nam Mexico c\u00f3 ngh\u0129a l\u00e0 m\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t r\u1ea5t l\u1edbn s\u1eafp n\u1ed5 ra. V\u00e0i th\u00e1ng sau, v\u00f9ng n\u00e0y \u0111\u00e3 g\u00e1nh ch\u1ecbu m\u1ed9t c\u01a1n \u0111\u1ed9ng \u0111\u1ea5t 7,7 \u0111\u1ed9 Richter, cho d\u00f9 m\u1ed1i li\u00ean k\u1ebft c\u1ee7a n\u00f3 v\u1edbi s\u1ef1 s\u1ee5t gi\u1ea3m ho\u1ea1t \u0111\u1ed9ng tr\u01b0\u1edbc \u0111\u00e2y l\u00e0 kh\u00f4ng bao gi\u1edd r\u00f5 r\u00e0ng. N\u0103m 1988, \u0111\u1ed9i kh\u1ea3o s\u00e1t \u0111\u1ecba ch\u1ea5t h\u1ecdc \u1edf M\u1ef9 \u0111\u00e3 c\u1ea3nh b\u00e1o r\u1eb1ng s\u1ebd c\u00f3 30% kh\u1ea3 n\u0103ng \u0111\u1ec3 m\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t x\u1ea3y ra \u1edf v\u00f9ng Loma Prieta c\u1ee7a California v\u00e0o m\u1ed9t l\u00fac n\u00e0o \u0111\u00f3 trong v\u00f2ng 30 n\u0103m t\u1edbi. L\u1eddi d\u1ef1 \u0111o\u00e1n \u0111\u00e3 th\u00e0nh s\u1ef1 th\u1eadt s\u1edbm h\u01a1n mong \u0111\u1ee3i: ng\u00e0y 18 th\u00e1ng 10 n\u0103m 1989, m\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t 7,1 \u0111\u1ed9 \u0111\u00e3 t\u1ea5n c\u00f4ng v\u00f9ng n\u00e0y, gi\u1ebft ch\u1ebft 62 ng\u01b0\u1eddi v\u00e0 g\u00e2y ra thi\u1ec7t h\u1ea1i nhi\u1ec1u t\u1ec9 \u0111\u00f4. M\u1ed9t l\u1ea7n n\u1eefa, ch\u1ec9 nh\u1eefng ng\u01b0\u1eddi theo d\u00f5i d\u1ec5 d\u00e3i nh\u1ea5t m\u1edbi t\u00ednh \u0111\u00e2y l\u00e0 m\u1ed9t l\u1eddi d\u1ef1 \u0111o\u00e1n h\u1eefu \u00edch. B\u1ea5t ch\u1ea5p s\u1ef1 ho\u00e0i nghi v\u00e0 th\u00f9 \u0111\u1ecbch, ph\u1ea7n th\u01b0\u1edfng ph\u1ea3i thu\u1ed9c v\u1ec1 nh\u00f3m c\u00e1c nh\u00e0 \u0111\u1ecba ch\u1ea5n h\u1ecdc t\u1ea1i \u0111\u1ea1i h\u1ecdc Athens, nh\u1eefng ng\u01b0\u1eddi \u0111\u00e3 th\u1ef1c hi\u1ec7n h\u00e0ng t\u00e1 d\u1ef1 b\u00e1o t\u1eeb 1987; t\u1ec9 l\u1ec7 th\u00e0nh c\u00f4ng c\u1ee7a c\u00e1c tuy\u00ean b\u1ed1 c\u1ee7a h\u1ecd kho\u1ea3ng 70%, v\u00e0 \u0111\u00e3 nh\u1eadn \u0111\u01b0\u1ee3c m\u1ed9t \u00edt s\u1ef1 tin t\u01b0\u1edfng. C\u00e1ch \u0111\u00e2y v\u00e0i n\u0103m, t\u00f4i \u0111\u00e3 nghi\u00ean c\u1ee9u nh\u1eefng t\u00ednh 60 https:\/\/thuviensach.vn","to\u00e1n \u0111\u1eb1ng sau nh\u1eefng d\u1ef1 \u0111o\u00e1n \u0111\u1ed9ng \u0111\u1ea5t v\u00e0 nh\u1eefng y\u00eau c\u1ea7u v\u1ec1 m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p d\u1ef1 \u0111o\u00e1n \u0111\u00e1ng tin c\u1eady, m\u00e0 l\u00fd t\u01b0\u1edfng l\u00e0 v\u1eeba kh\u00f4ng b\u1ecf s\u00f3t m\u1ed9t s\u1ef1 ki\u1ec7n c\u00f3 th\u1ef1c v\u1eeba kh\u00f4ng b\u00e1o \u0111\u1ed9ng gi\u1ea3. Th\u1eadt may m\u1eafn, nh\u1eefng tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t l\u1edbn hi\u1ebfm khi x\u1ea3y ra; c\u00f2n kh\u00f4ng may l\u00e0, \u0111i\u1ec1u n\u00e0y c\u0169ng c\u00f3 ngh\u0129a r\u1eb1ng tr\u1eeb khi l\u1eddi d\u1ef1 b\u00e1o ph\u1ea3i c\u1ef1c k\u1ef3 \u0111\u00e1ng tin, n\u1ebfu kh\u00f4ng n\u00f3 h\u1ea7u nh\u01b0 ch\u1eafc ch\u1eafn s\u1ebd l\u00e0 m\u1ed9t b\u00e1o \u0111\u1ed9ng gi\u1ea3. \u0110\u1ec3 m\u1ed9t h\u1ec7 th\u1ed1ng d\u1ef1 b\u00e1o l\u00e0 th\u1ef1c s\u1ef1 h\u1eefu d\u1ee5ng, n\u00f3 s\u1ebd ph\u1ea3i ch\u00ednh x\u00e1c h\u01a1n t\u1ed1i thi\u1ec3u l\u00e0 100 l\u1ea7n so v\u1edbi nh\u1eefng d\u1ef1 b\u00e1o th\u1eddi ti\u1ebft t\u1ed1t nh\u1ea5t t\u1eebng \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n. Ho\u1ea1t \u0111\u1ed9ng c\u1ef1c k\u1ef3 ph\u1ee9c t\u1ea1p c\u1ee7a nh\u1eefng t\u1ea3ng \u0111\u00e1 b\u1ecb v\u1ee1 d\u01b0\u1edbi s\u1ee9c \u00e9p v\u00e0 c\u0103ng l\u00e0m cho \u0111i\u1ec1u n\u00e0y tr\u1edf th\u00e0nh m\u1ed9t vi\u1ec5n c\u1ea3nh t\u1ed1i t\u0103m. Do \u0111\u00f3, m\u1ed9t s\u1ef1 \u0111\u1eb7t c\u01b0\u1ee3c an to\u00e0n l\u00e0: vi\u1ec7c x\u00e1c \u0111\u1ecbnh th\u1eddi gian v\u00e0 \u0111\u1ecba \u0111i\u1ec3m c\u1ee7a m\u1ed9t tr\u1eadn \u0111\u1ed9ng \u0111\u1ea5t l\u1edbn s\u1ebd kh\u00f4ng bao gi\u1edd \u0111\u01b0\u1ee3c d\u1ef1 \u0111o\u00e1n h\u1eefu hi\u1ec7u - nh\u01b0ng \u0111i\u1ec1u n\u00e0y v\u1eabn kh\u00f4ng ng\u0103n \u0111\u01b0\u1ee3c ng\u01b0\u1eddi ta ti\u1ebfp t\u1ee5c c\u1ed1 g\u1eafng. 45 T\u1ea1i sao c\u1ef1c b\u1eafc c\u1ee7a t\u1eeb tr\u01b0\u1eddng tr\u00e1i \u0111\u1ea5t kh\u00f4ng n\u1eb1m \u1edf B\u1eafc c\u1ef1c? V\u1ecb tr\u00ed c\u1ee7a b\u1eafc t\u1eeb tr\u01b0\u1eddng ph\u01b0\u01a1ng B\u1eafc ch\u01b0a bao gi\u1edd tr\u00f9ng v\u1edbi h\u01b0\u1edbng B\u1eafc th\u1eadt s\u1ef1 v\u00e0 n\u00f3 c\u0169ng kh\u00f4ng n\u1eb1m c\u1ed1 \u0111\u1ecbnh theo nh\u1eefng b\u00e1o c\u00e1o b\u1eaft \u0111\u1ea7u c\u00e1ch \u0111\u00e2y t\u1eeb h\u01a1n 500 n\u0103m v\u00e0 cho t\u1edbi gi\u1eefa th\u1ebf k\u1ef7 19 th\u00ec n\u00f3 c\u00f2n c\u00e1ch xa h\u01a1n bao gi\u1edd h\u1ebft. Sau \u0111\u00f3, c\u00e1ch \u0111\u00e2y kho\u1ea3ng 150 n\u0103m, n\u00f3 b\u1eaft \u0111\u1ea7u h\u01b0\u1edbng tr\u1edf l\u1ea1i ph\u00eda b\u1eafc, t\u1ea1o n\u00ean m\u1ed9t con \u0111\u01b0\u1eddng quanh co gi\u1eefa c\u00e1c \u0111\u1ea3o ph\u00eda B\u1eafc Canada. Trong m\u01b0\u1eddi 61 https:\/\/thuviensach.vn","n\u0103m v\u1eeba qua s\u1ef1 ti\u1ebfn t\u1edbi v\u1ec1 h\u01b0\u1edbng b\u1eafc c\u1ee7a n\u00f3 \u0111\u00e3 gia t\u1ed1c m\u1ed9t c\u00e1ch \u0111\u00e1ng ch\u00fa \u00fd v\u00e0 l\u00ean t\u1edbi kho\u1ea3ng 40km m\u1ed7i n\u0103m, mang n\u00f3 t\u1edbi v\u1ecb tr\u00ed hi\u1ec7n t\u1ea1i c\u00e1ch xa kho\u1ea3ng 966km so v\u1edbi \u0111i\u1ec3m c\u1ef1c B\u1eafc, \u1edf 800 v\u0129 b\u1eafc - 1100 kinh t\u00e2y. L\u1eddi gi\u1ea3i th\u00edch cho vi\u1ec7c \u0111i quanh co c\u1ee7a n\u00f3 n\u1eb1m \u1edf qu\u00e1 tr\u00ecnh t\u1ea1o th\u00e0nh t\u1eeb tr\u01b0\u1eddng tr\u00e1i \u0111\u1ea5t, m\u1ed9t qu\u00e1 tr\u00ecnh v\u1eabn ch\u01b0a \u0111\u01b0\u1ee3c hi\u1ec3u r\u00f5 ho\u00e0n to\u00e0n. \u0110\u1ea1i kh\u00e1i, t\u1eeb tr\u01b0\u1eddng \u0111\u01b0\u1ee3c cho l\u00e0 t\u1ea1o ra b\u1edfi \u201chi\u1ec7u \u1ee9ng \u0111\u1ed9ng\u201d, t\u01b0\u01a1ng t\u1ef1 v\u1edbi hi\u1ec7u \u1ee9ng \u0111\u00e3 bi\u1ebfn s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a b\u00e1nh xe \u0111\u1ea1p th\u00e0nh n\u0103ng l\u01b0\u1ee3ng \u0111i\u1ec7n. Trong tr\u00e1i \u0111\u1ea5t, s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng l\u00e0 c\u1ee7a nh\u1eefng d\u00f2ng \u0111\u1ed1i l\u01b0u kh\u1ed5ng l\u1ed3 c\u1ee7a s\u1eaft n\u00f3ng ch\u1ea3y b\u00ean d\u01b0\u1edbi l\u1edbp v\u1ecf tr\u00e1i \u0111\u1ea5t, g\u1ea7n 3.000km d\u01b0\u1edbi ch\u00e2n ch\u00fang ta. S\u1ef1 l\u00ean v\u00e0 xu\u1ed1ng ch\u1eadm ch\u1ea1p c\u1ee7a nh\u1eefng d\u00f2ng ch\u1ea3y n\u00e0y, c\u00f9ng v\u1edbi nh\u1eefng hi\u1ec7u \u1ee9ng g\u00e2y ra b\u1edfi s\u1ef1 quay c\u1ee7a tr\u00e1i \u0111\u1ea5t, t\u1ea1o ra m\u1ed9t d\u00f2ng \u0111i\u1ec7n c\u00f9ng v\u1edbi m\u1ed9t t\u1eeb tr\u01b0\u1eddng, t\u01b0\u01a1ng t\u1ef1 m\u1ed9t thanh nam ch\u00e2m \u0111\u01a1n gi\u1ea3n, nghi\u00eang \u0111i m\u1ed9t ch\u00fat so v\u1edbi tr\u1ee5c xoay c\u1ee7a h\u00e0nh tinh ch\u00fang ta. Theo h\u1ecdc thuy\u1ebft n\u00e0y, l\u00fd do m\u00e0 c\u1ef1c b\u1eafc c\u1ee7a t\u1eeb tr\u01b0\u1eddng kh\u00f4ng tr\u00f9ng v\u1edbi h\u01b0\u1edbng B\u1eafc th\u1ef1c l\u00e0 v\u00ec s\u1ef1 quay c\u1ee7a tr\u00e1i \u0111\u1ea5t ch\u1ec9 gi\u1eef vai tr\u00f2 th\u1ee9 y\u1ebfu trong s\u1ef1 t\u1ea1o ra t\u1eeb tr\u01b0\u1eddng, c\u00f2n \u0111\u1ec3 gi\u1ea3i th\u00edch v\u1ecb tr\u00ed ch\u00ednh x\u00e1c c\u1ee7a b\u1eafc t\u1eeb tr\u01b0\u1eddng th\u00ec l\u1ea1i th\u1ef1c s\u1ef1 l\u00e0 m\u1ed9t v\u1ea5n \u0111\u1ec1 kh\u00e1c. N\u0103m 1995, Gary Glatzmaier c\u1ee7a Ph\u00f2ng th\u00ed nghi\u1ec7m qu\u1ed1c gia Los Alamos, New Mexico v\u00e0 Paul Roberts c\u1ee7a \u0110\u1ea1i h\u1ecdc California, Los Angeles \u0111\u00e3 s\u1eed d\u1ee5ng ph\u01b0\u01a1ng ph\u00e1p m\u00f4 ph\u1ecfng b\u1eb1ng si\u00eau m\u00e1y t\u00ednh nh\u1eefng g\u00ec b\u00ean trong tr\u00e1i \u0111\u1ea5t \u0111\u1ec3 ch\u1ee9ng minh r\u1eb1ng v\u1ecb tr\u00ed c\u1ee7a c\u00e1c c\u1ef1c t\u1eeb tr\u01b0\u1eddng l\u00e0 k\u1ebft qu\u1ea3 c\u1ee7a cu\u1ed9c chi\u1ebfn \u0111\u1ea5u 62 https:\/\/thuviensach.vn","li\u00ean t\u1ee5c gi\u1eefa ch\u1ea5t l\u1ecfng \u1edf ph\u1ea7n l\u00f5i ngo\u00e0i (\u0111ang c\u1ed1 k\u00e9o t\u1eeb tr\u01b0\u1eddng v\u1ec1 b\u00ean ph\u1ea3i) v\u00e0 ch\u1ea5t r\u1eafn \u1edf ph\u1ea7n l\u00f5i trong (\u0111ang ch\u1ed1ng l\u1ea1i hi\u1ec7u \u1ee9ng kia). R\u1ea5t th\u01b0\u1eddng xuy\u00ean, ph\u1ea7n l\u00f5i r\u1eafn b\u00ean trong th\u1ea5t b\u1ea1i v\u00e0 t\u1eeb tr\u01b0\u1eddng tr\u00e1i \u0111\u1ea5t tr\u1ea3i qua m\u1ed9t s\u1ef1 \u0111\u1ea3o l\u1ed9n ho\u00e0n to\u00e0n, v\u1edbi b\u1eafc t\u1eeb tr\u01b0\u1eddng tr\u1edf th\u00e0nh nam v\u00e0 ng\u01b0\u1ee3c l\u1ea1i. 46 \u0110i\u1ec1u g\u00ec s\u1ebd x\u1ea3y ra khi c\u00e1c c\u1ef1c t\u1eeb tr\u01b0\u1eddng c\u1ee7a tr\u00e1i \u0111\u1ea5t \u0111\u1ea3o ng\u01b0\u1ee3c \u0111i? Kh\u00f4ng c\u00f3 g\u00ec \u0111\u00e1ng ng\u1edd r\u1eb1ng, v\u00e0o l\u00fac n\u00e0o \u0111\u00f3 trong t\u01b0\u01a1ng lai c\u00e1c c\u1ef1c t\u1eeb tr\u01b0\u1eddng c\u1ee7a tr\u00e1i \u0111\u1ea5t s\u1ebd \u0111\u1ea3o ng\u01b0\u1ee3c. Nh\u1eefng nghi\u00ean c\u1ee9u v\u1ec1 dung nham c\u1ed5 \u0111\u1ea1i \u0111\u00f4ng \u0111\u1eb7c l\u1ea1i theo h\u01b0\u1edbng t\u1eeb tr\u01b0\u1eddng khi b\u1ecb l\u00e0m l\u1ea1nh, cho th\u1ea5y r\u1eb1ng s\u1ef1 \u0111\u1ea3o ng\u01b0\u1ee3c nh\u01b0 v\u1eady \u0111\u00e3 x\u1ea3y ra 20 l\u1ea7n trong v\u00f2ng 5 tri\u1ec7u n\u0103m qua, l\u1ea7n g\u1ea7n nh\u1ea5t c\u00e1ch \u0111\u00e2y kho\u1ea3ng 780 ng\u00e0n n\u0103m. S\u1ef1 \u0111\u1ea3o ng\u01b0\u1ee3c t\u1ed1n kho\u1ea3ng 5-10 ng\u00e0n n\u0103m, trong th\u1eddi gian \u0111\u00f3 tr\u00e1i \u0111\u1ea5t ch\u1ec9 c\u00f2n l\u1ea1i r\u1ea5t \u00edt hay kh\u00f4ng c\u00f2n t\u1eeb tr\u01b0\u1eddng. Theo m\u1ed9t v\u00e0i nh\u00e0 khoa h\u1ecdc, m\u1ed9t s\u1ef1 \u0111\u1ea3o ng\u01b0\u1ee3c kh\u00e1c s\u1eafp x\u1ea3y ra (\u00edt nh\u1ea5t l\u00e0 theo quan \u0111i\u1ec3m \u0111\u1ecba ch\u1ea5t h\u1ecdc). T\u1eeb tr\u01b0\u1eddng c\u1ee7a tr\u00e1i \u0111\u1ea5t \u0111\u00e3 y\u1ebfu \u0111i t\u1eeb kho\u1ea3ng th\u1eddi gian \u0111\u1ea7u c\u00f4ng nguy\u00ean v\u00e0 v\u1edbi t\u1ed1c \u0111\u1ed9 hi\u1ec7n t\u1ea1i th\u00ec s\u1ebd bi\u1ebfn m\u1ea5t ho\u00e0n to\u00e0n trong v\u00f2ng v\u00e0i ng\u00e0n n\u0103m n\u1eefa. Li\u1ec7u \u0111i\u1ec1u n\u00e0y c\u00f3 \u1ea3nh h\u01b0\u1edfng g\u00ec nhi\u1ec1u t\u1edbi s\u1ef1 s\u1ed1ng hay kh\u00f4ng c\u00f2n ch\u01b0a bi\u1ebft \u0111\u01b0\u1ee3c. \u0110\u00fang l\u00e0 nh\u1eefng tia ph\u00f3ng x\u1ea1 c\u00f3 kh\u1ea3 n\u0103ng g\u00e2y nguy 63 https:\/\/thuviensach.vn","hi\u1ec3m t\u1eeb m\u1eb7t tr\u1eddi v\u00e0 ngo\u1ea1i t\u1ea7ng kh\u00f4ng gian \u0111ang b\u1ecb b\u1eaft gi\u1eef b\u1edfi t\u1eeb tr\u01b0\u1eddng tr\u00e1i \u0111\u1ea5t trong v\u00e0nh \u0111ai Van Allen, n\u1eb1m gi\u1eefa kho\u1ea3ng 4.800 \u0111\u1ebfn 28.000km tr\u00ean h\u00e0nh tinh ch\u00fang ta. V\u00e0 c\u0169ng \u0111\u00fang l\u00e0 m\u1eadt \u0111\u1ed9 ph\u00f3ng x\u1ea1 \u1edf nh\u1eefng v\u00f9ng n\u00e0y l\u00e0 \u0111\u1ee7 cao \u0111\u1ec3 t\u1ea1o ra m\u1ed9t m\u1ed1i nguy hi\u1ec3m n\u00e0o \u0111\u00f3 cho b\u1ea5t c\u1ee9 v\u1eadt g\u00ec hay b\u1ea5t c\u1ee9 ai n\u00e1n l\u1ea1i \u1edf \u0111\u00e2y. Tuy nhi\u00ean, ngay c\u1ea3 khi v\u00e0nh \u0111ai n\u00e0y bi\u1ebfn m\u1ea5t trong l\u00fac \u0111\u1ea3o ng\u01b0\u1ee3c t\u1eeb tr\u01b0\u1eddng, ta c\u0169ng kh\u00f4ng ch\u1eafc \u0111\u01b0\u1ee3c r\u1eb1ng nh\u1eefng tia ph\u00f3ng x\u1ea1 \u0111\u1ebfn \u0111\u01b0\u1ee3c tr\u00e1i \u0111\u1ea5t s\u1ebd g\u00e2y ra nhi\u1ec1u v\u1ea5n \u0111\u1ec1, b\u1edfi v\u00ec kh\u00ed quy\u1ec3n s\u1ebd v\u1eabn t\u00f3m l\u1ea5y h\u1ea7u h\u1ebft t\u1ea5t c\u1ea3 tr\u01b0\u1edbc khi ch\u00fang \u0111\u1ebfn \u0111\u01b0\u1ee3c m\u1eb7t \u0111\u1ea5t. T\u00e1c \u0111\u1ed9ng hi\u1ec3n nhi\u00ean nh\u1ea5t c\u1ee7a vi\u1ec7c t\u1eeb tr\u01b0\u1eddng bi\u1ebfn m\u1ea5t s\u1ebd l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng c\u1ef1c quang ngo\u1ea1n m\u1ee5c, do nhi\u1ec1u h\u1ea1t di chuy\u1ec3n nhanh h\u01a1n va \u0111\u1eadp v\u00e0o c\u00e1c ph\u00e2n t\u1eed kh\u00f4ng kh\u00ed \u1edf ph\u1ea7n tr\u00ean kh\u00ed quy\u1ec3n. 47 Li\u1ec7u m\u1ed9t b\u1edd bi\u1ec3n \u1edf qu\u1ea7n \u0111\u1ea3o Canary c\u00f3 th\u1ec3 t\u1ea1o ra m\u1ed9t c\u01a1n s\u00f3ng th\u1ea7n l\u1edbn kh\u00f4ng? N\u0103m 2000, nh\u1eefng c\u00e2u chuy\u1ec7n kh\u1ea3i huy\u1ec1n b\u1eaft \u0111\u1ea7u truy\u1ec1n b\u00e1 v\u1ec1 kh\u1ea3 n\u0103ng s\u1ee5p \u0111\u1ed5 c\u1ee7a Cumbre Vieja, m\u1ed9t n\u00fai l\u1eeda tr\u00ean \u0111\u1ea3o La Palma thu\u1ed9c qu\u1ea7n \u0111\u1ea3o Canary. S\u01b0\u1eddn ph\u00eda t\u00e2y c\u1ee7a n\u00f3 t\u00e1ch ra kh\u1ecfi ph\u1ea7n c\u00f2n l\u1ea1i v\u00e0 tr\u00f4ng nh\u01b0 s\u1eafp r\u01a1i xu\u1ed1ng bi\u1ec3n. V\u1edbi m\u1ed9t kh\u1ed1i l\u01b0\u1ee3ng \u01b0\u1edbc t\u00ednh kho\u1ea3ng m\u1ed9t tri\u1ec7u t\u1ec9 t\u1ea5n, l\u01b0\u1ee3ng n\u01b0\u1edbc b\u1eafn l\u00ean \u1eaft h\u1eb3n s\u1ebd r\u1ea5t ngo\u1ea1n m\u1ee5c, \u0111\u00fang h\u01a1n l\u00e0 kh\u1ee7ng khi\u1ebfp. Th\u1eadt v\u1eady, theo m\u1ed9t v\u00e0i nh\u00e0 khoa h\u1ecdc, n\u00f3 s\u1ebd sinh ra m\u1ed9t c\u01a1n s\u00f3ng th\u1ea7n cao kho\u1ea3ng 64 https:\/\/thuviensach.vn","1.000 m, tr\u00e0n ra v\u00e0 h\u1ee7y di\u1ec7t \u0111\u01b0\u1eddng b\u1edd bi\u1ec3n ch\u00e2u Phi, ch\u00e2u \u00c2u v\u00e0 ch\u00e2u M\u1ef9. T\u1ea1i sao kh\u00f4ng c\u00f3 ai l\u00e0m g\u00ec c\u1ea3? Th\u1ee9 nh\u1ea5t, kh\u00f4ng ai bi\u1ebft kh\u1ea3 n\u0103ng n\u00f3 s\u1ebd x\u1ea3y ra l\u00e0 bao nhi\u00eau: s\u1ef1 l\u1edf \u0111\u1ea5t c\u00f3 th\u1ec3 x\u1ea3y ra n\u0103m t\u1edbi hay m\u01b0\u1eddi ng\u00e0n n\u0103m t\u1edbi. Th\u1ee9 hai, ngo\u00e0i vi\u1ec7c di t\u1ea3n m\u01b0\u1eddi tri\u1ec7u d\u00e2n \u1edf nh\u1eefng v\u00f9ng b\u1ecb \u0111e do\u1ea1 th\u00ec h\u1ea7u nh\u01b0 kh\u00f4ng c\u00f2n c\u00f3 th\u1ec3 l\u00e0m g\u00ec. Ch\u1eafc ch\u1eafn l\u00e0 kh\u00f4ng c\u00f3 hy v\u1ecdng n\u00e0o bu\u1ed9c ch\u1eb7t hay n\u00e2ng \u0111\u1ee1 m\u1ed9t c\u1ea5u tr\u00fac kh\u1ed5ng l\u1ed3 nh\u01b0 v\u1eady. R\u1ea5t nhi\u1ec1u chuy\u00ean gia tin r\u1eb1ng c\u00f3 m\u1ed9t chi\u1ebfn l\u01b0\u1ee3c c\u00f3 th\u1ec3 c\u00f3 hi\u1ec7u qu\u1ea3 cao \u0111\u1ec3 \u0111\u1ed1i ph\u00f3 v\u1edbi m\u1ed1i \u0111e do\u1ea1 n\u00e0y: qu\u00ean h\u1ebft n\u00f3 \u0111i. N\u0103m 2003, m\u1ed9t \u1ee7y ban c\u00e1c chuy\u00ean gia \u0111\u00e3 ph\u00e1t h\u00e0nh m\u1ed9t th\u00f4ng c\u00e1o ch\u00ednh th\u1ee9c m\u00e0 h\u1ecd hy v\u1ecdng r\u1eb1ng s\u1ebd \u201cch\u1eb7n \u0111\u1ee9ng vi\u1ec7c phao tin \u0111\u1ed3n c\u00e1c b\u00e1o c\u00e1o kh\u00f4ng c\u00f3 c\u01a1 s\u1edf\u201d n\u00e0y. Theo \u1ee7y ban n\u00e0y, c\u00e1c th\u00ed nghi\u1ec7m v\u00e0 s\u1ef1 m\u00f4 ph\u1ecfng b\u1eb1ng m\u00e1y t\u00ednh \u0111\u00e3 \u0111\u01b0\u1ee3c ti\u1ebfn h\u00e0nh \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 m\u1ed1i \u0111e do\u1ea1 t\u1eeb La Palma v\u00e0 h\u1ecd \u0111\u00e3 ch\u1ec9 ra r\u1eb1ng c\u01a1n s\u00f3ng th\u1ea7n \u0111\u00f3 s\u1ebd kh\u00f4ng g\u00e2y ra b\u1ea5t c\u1ee9 th\u1ee9 g\u00ec gi\u1ed1ng v\u1edbi nh\u1eefng m\u1ed1i \u0111e do\u1ea1 \u0111\u00e3 t\u1eebng \u0111\u01b0\u1ee3c tuy\u00ean b\u1ed1 v\u1ec1 n\u00f3. T\u1eeb khi th\u00f4ng c\u00e1o ch\u00ednh th\u1ee9c n\u00e0y \u0111\u01b0\u1ee3c ph\u00e1t h\u00e0nh, c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u1edf Trung t\u00e2m h\u1ea3i d\u01b0\u01a1ng h\u1ecdc Southampton \u0111\u00e3 xu\u1ea5t b\u1ea3n k\u1ebft qu\u1ea3 c\u00e1c nghi\u00ean c\u1ee9u v\u1ec1 s\u1ef1 l\u1edf \u0111\u1ea5t th\u1eddi c\u1ed5 \u0111\u1ea1i c\u1ee7a La Palma v\u00e0 nh\u1eefng n\u01a1i kh\u00e1c, g\u1ee3i \u00fd r\u1eb1ng n\u00f3 s\u1ebd x\u1ea3y ra t\u1eebng ch\u00fat m\u1ed9t ch\u1ee9 kh\u00f4ng ph\u1ea3i t\u1ea5t c\u1ea3 c\u00f9ng m\u1ed9t l\u00fac. 65 https:\/\/thuviensach.vn","48 T\u1ea1i sao b\u00ean trong tr\u00e1i \u0111\u1ea5t v\u1eabn n\u00f3ng sau nhi\u1ec1u t\u1ec9 n\u0103m? C\u00e2u tr\u1ea3 l\u1eddi c\u00f3 v\u1ebb r\u1ea5t r\u00f5 r\u00e0ng: tr\u00e1i \u0111\u1ea5t v\u1eabn \u0111ang trong qu\u00e1 tr\u00ecnh l\u1ea1nh \u0111i t\u1eeb tr\u1ea1ng th\u00e1i n\u00f3ng ch\u1ea3y ban \u0111\u1ea7u c\u1ee7a n\u00f3. Tuy nhi\u00ean, vi\u1ec7c t\u00ednh to\u00e1n s\u01a1 b\u1ed9 t\u1ed1c \u0111\u1ed9 l\u00e0m l\u1ea1nh c\u1ee7a m\u1ed9t qu\u1ea3 c\u1ea7u n\u00f3ng ch\u1ea3y c\u00f3 k\u00edch th\u01b0\u1edbc c\u1ee7a tr\u00e1i \u0111\u1ea5t c\u00f3 th\u1ec3 ch\u1ea5m d\u1ee9t \u00fd t\u01b0\u1edfng n\u00e0y: h\u00e0nh tinh ch\u00fang ta l\u1ebd ra \u0111\u00e3 tr\u1edf th\u00e0nh m\u1ed9t c\u1ee5c \u0111\u00e1 l\u1ea1nh c\u00e1ch \u0111\u00e2y h\u00e0ng t\u1ec9 n\u0103m, tuy nhi\u00ean l\u01b0\u1ee3ng magma n\u00f3ng ch\u1ea3y \u0111\u01b0\u1ee3c phun ra b\u1edfi c\u00e1c n\u00fai l\u1eeda v\u00e0 s\u1ee9c n\u00f3ng \u00e2m \u1ec9 \u1edf \u0111\u00e1y c\u00e1c h\u1ea7m m\u1ecf s\u00e2u \u0111\u00e3 ch\u1ee9ng minh l\u00e0 kh\u00f4ng ph\u1ea3i. \u0110i\u1ec1u n\u00e0y g\u1ee3i \u00fd r\u1eb1ng c\u00f3 c\u00e1i g\u00ec \u0111\u00f3 \u0111ang ho\u1ea1t \u0111\u1ed9ng nh\u01b0 l\u00e0 m\u1ed9t ngu\u1ed3n cung c\u1ea5p nhi\u1ec7t l\u01b0\u1ee3ng. C\u00e1i g\u00ec \u0111\u00f3 ch\u00ednh l\u00e0 ho\u1ea1t \u0111\u1ed9ng ph\u00f3ng x\u1ea1, sinh ra b\u1edfi m\u1ed9t \u00edt uranium, thorium v\u00e0 potassium b\u1ecb gi\u1eef b\u00ean trong tr\u00e1i \u0111\u1ea5t khi tr\u00e1i \u0111\u1ea5t h\u00ecnh th\u00e0nh. Khi ch\u00fang d\u1ea7n d\u1ea7n ph\u00e2n h\u1ee7y, ch\u00fang gi\u1ea3i ph\u00f3ng ra c\u00e1c h\u1ea1t, c\u00e1c h\u1ea1t n\u00e0y va v\u00e0o v\u1eadt ch\u1ea5t xung quanh, l\u00e0m n\u00f3ng n\u00f3 l\u00ean t\u1edbi nhi\u1ec7t \u0111\u1ed9 cao kho\u1ea3ng 5.5000C \u1edf l\u00f5i tr\u00e1i \u0111\u1ea5t. \u1ede b\u1ec1 m\u1eb7t, t\u1ea5t c\u1ea3 nhi\u1ec7t l\u01b0\u1ee3ng n\u00e0y r\u00f2 r\u1ec9 d\u1ea7n d\u1ea7n v\u1edbi m\u1ed9t t\u1ed1c \u0111\u1ed9 trung b\u00ecnh kho\u1ea3ng 60 kilowatt m\u1ed7i km2. T\u00f3m l\u1ea1i, t\u1ea5t c\u1ea3 ch\u00fang ta \u0111ang s\u1ed1ng b\u00ean tr\u00ean m\u1ed9t m\u1ed9t l\u00f2 ph\u1ea3n \u1ee9ng h\u1ea1t nh\u00e2n s\u00f4i s\u1ee5c kh\u1ed5ng l\u1ed3. M\u1ed9t \u00fd ngh\u0129 th\u1eadt \u0111\u00e1ng s\u1ee3. 66 https:\/\/thuviensach.vn","N\u1ebfu b\u00ean trong tr\u00e1i \u0111\u1ea5t b\u1ecb 49 n\u00f3ng ch\u1ea3y, t\u1ea1i sao s\u1ee9c n\u00f3ng ch\u1ec9 l\u00ean t\u1edbi b\u1ec1 m\u1eb7t t\u1ea1i c\u00e1c n\u00fai l\u1eeda? Tr\u00e1i \u0111\u1ea5t th\u01b0\u1eddng \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 nh\u01b0 l\u00e0 m\u1ed9t qu\u1ea3 c\u1ea7u kh\u1ed5ng l\u1ed3 c\u1ee7a dung nham n\u00f3ng ch\u1ea3y ch\u1ee9a \u0111\u1ef1ng b\u00ean trong m\u1ed9t l\u1edbp da d\u00e0y 32km b\u1eb1ng \u0111\u00e1. Tuy nhi\u00ean s\u1ef1 ph\u00e2n t\u00edch c\u00e1c s\u00f3ng \u0111\u1ed9ng \u0111\u1ea5t truy\u1ec1n qua tr\u00e1i \u0111\u1ea5t cho th\u1ea5y r\u1eb1ng n\u00f3 ho\u00e0n to\u00e0n l\u00e0 ch\u1ea5t r\u1eafn t\u1eeb kho\u1ea3ng 200km b\u00ean d\u01b0\u1edbi b\u1ec1 m\u1eb7t tr\u00e1i \u0111\u1ea5t xu\u1ed1ng ph\u1ea7n l\u00f5i ngo\u00e0i. \u00c1p su\u1ea5t kh\u1ed5ng l\u1ed3 t\u1ea1o ra b\u1edfi nhi\u1ec1u l\u1edbp ch\u1ed3ng ch\u1ea5t n\u00e0y \u0111\u00e3 n\u00e2ng \u0111i\u1ec3m n\u00f3ng ch\u1ea3y c\u1ee7a \u0111\u00e1 l\u00ean t\u1edbi m\u1ee9c m\u00e0 n\u00f3 v\u1eabn gi\u1eef \u0111\u01b0\u1ee3c b\u1ea3n ch\u1ea5t r\u1eafn b\u1ea5t ch\u1ea5p r\u1eb1ng n\u00f3 \u0111ang \u1edf m\u1ed9t nhi\u1ec7t \u0111\u1ed9 \u0111\u00e3 cao h\u01a1n 1.7000C. D\u00f9 v\u1eady, \u0111\u00e1 v\u1eabn c\u00f3 th\u1ec3 ch\u1ea3y \u0111i v\u1edbi t\u00e1c \u0111\u1ed9ng c\u1ee7a nh\u1eefng l\u1ef1c r\u1ea5t l\u1edbn - c\u0169ng gi\u1ed1ng nh\u01b0 mi\u1ebfng kim lo\u1ea1i r\u1eafn \u1edf m\u00f3ng ng\u1ef1a tr\u1edf n\u00ean d\u1ec5 u\u1ed1n \u1edf nhi\u1ec7t \u0111\u1ed9 n\u00f3ng \u0111\u1ecf v\u00e0 c\u00f3 th\u1ec3 b\u1ecb \u00e9p th\u00e0nh nhi\u1ec1u h\u00ecnh d\u1ea1ng kh\u00e1c nhau. L\u1edbp v\u1ecf tr\u00e1i \u0111\u1ea5t kh\u00e1 m\u1ecfng - t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi l\u1edbp gi\u1ea5y l\u1ee5a d\u00e1n b\u00ean ngo\u00e0i m\u1ed9t qu\u1ea3 cam - nh\u01b0ng n\u00f3 v\u1eabn nh\u1eadn r\u1ea5t nhi\u1ec1u nhi\u1ec7t l\u01b0\u1ee3ng t\u1eeb b\u00ean d\u01b0\u1edbi \u0111\u1ec3 \u0111\u1ed1t tr\u00ean su\u1ed1t qu\u00e3ng \u0111\u01b0\u1eddng ngang qua n\u00f3 l\u00ean b\u1ec1 m\u1eb7t. Magma th\u01b0\u1eddng \u0111\u1ebfn b\u1ec1 m\u1eb7t qua nh\u1eefng v\u1ebft n\u1ee9t b\u00ean trong hay gi\u1eefa c\u00e1c \u0111\u1ecba t\u1ea7ng ki\u1ebfn t\u1ea1o kh\u1ed5ng l\u1ed3 \u0111\u00e3 t\u1ea1o n\u00ean v\u1ecf tr\u00e1i \u0111\u1ea5t. Bi\u1ec3u hi\u1ec7n ngo\u1ea1n m\u1ee5c nh\u1ea5t c\u1ee7a \u0111i\u1ec1u n\u00e0y l\u00e0 \u201cV\u00e0nh \u0111ai l\u1eeda\u201d, s\u1ef1 s\u1eafp x\u1ebfp theo v\u00f2ng tr\u00f2n c\u1ee7a c\u00e1c n\u00fai l\u1eeda \u1edf xung quanh b\u1edd Th\u00e1i B\u00ecnh D\u01b0\u01a1ng. Magma \u0111\u00f4i khi c\u00f3 th\u1ec3 phun th\u1eb3ng qua l\u1edbp v\u1ecf khi m\u1ed9t \u201cch\u00f9m v\u1ecf\u201d - m\u1ed9t kh\u1ed1i magma kh\u1ed5ng l\u1ed3 c\u1ef1c n\u00f3ng c\u00f3 d\u1ea1ng ng\u00f3n tay h\u00ecnh th\u00e0nh \u1edf bi\u00ean gi\u1edbi gi\u1eefa l\u1edbp v\u1ecf v\u00e0 67 https:\/\/thuviensach.vn","ph\u1ea7n l\u00f5i ngo\u00e0i, kho\u1ea3ng 3.000km b\u00ean d\u01b0\u1edbi, v\u1ee1 r\u1eddi ra v\u00e0 d\u00e2ng l\u00ean b\u1ec1 m\u1eb7t, k\u00edch th\u00edch m\u1ed9t c\u01a1n b\u00f9ng n\u1ed5 c\u1ef1c l\u1edbn c\u1ee7a ho\u1ea1t \u0111\u1ed9ng n\u00fai l\u1eeda. M\u1ed9t ch\u00f9m v\u1ecf c\u0169ng \u0111\u00e3 phun ra 1 tri\u1ec7u km3 dung nham v\u00e0o n\u01a1i m\u00e0 hi\u1ec7n gi\u1edd l\u00e0 Deccan Traps \u1edf \u1ea4n \u0110\u1ed9 c\u00e1ch \u0111\u00e2y 65 tri\u1ec7u n\u0103m - m\u1ed9t s\u1ef1 ki\u1ec7n m\u00e3nh li\u1ec7t ngo\u00e0i s\u1ee9c t\u01b0\u1edfng t\u01b0\u1ee3ng, v\u1edbi nh\u1eefng hi\u1ec7u \u1ee9ng kh\u00ed h\u1eadu \u0111\u00e3 gi\u00fap \u0111\u1ea9y c\u00e1c lo\u00e0i kh\u1ee7ng long v\u00e0o s\u1ef1 tuy\u1ec7t ch\u1ee7ng. T\u1eeb \u0111\u00f3 s\u1ef1 tr\u00f4i l\u1ee5c \u0111\u1ecba \u0111\u00e3 di chuy\u1ec3n \u0111i\u1ec3m m\u00e0 ch\u00f9m v\u1ecf tr\u1ed3i l\u00ean b\u1ec1 m\u1eb7t t\u1edbi \u0111\u1ea3o Reunion \u1edf \u1ea4n \u0110\u1ed9 D\u01b0\u01a1ng. Nhi\u1ec7t l\u01b0\u1ee3ng tho\u00e1t ra kh\u1ecfi tr\u00e1i \u0111\u1ea5t \u1edf t\u1ed1c \u0111\u1ed9 kho\u1ea3ng 44 ng\u00e0n t\u1ec9 t\u1ec9 watt - h\u01a1n 100 l\u1ea7n nhi\u1ec7t l\u01b0\u1ee3ng \u0111\u01b0\u1ee3c sinh ra b\u1edfi t\u1ea5t c\u1ea3 c\u00e1c nh\u00e0 m\u00e1y \u0111i\u1ec7n nguy\u00ean t\u1eed c\u1ee7a th\u1ebf gi\u1edbi - do \u0111\u00f3 nhi\u1ec1u n\u1ed7 l\u1ef1c \u0111\u00e3 \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n \u0111\u1ec3 khai th\u00e1c ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng t\u1ef1 do n\u00e0y. K\u1ebf ho\u1ea1ch n\u0103ng l\u01b0\u1ee3ng \u0111\u1ecba nhi\u1ec7t th\u01b0\u1eddng li\u00ean quan t\u1edbi vi\u1ec7c b\u01a1m n\u01b0\u1edbc v\u00e0o nh\u1eefng \u0111\u01b0\u1eddng \u1ed1ng \u0111\u1eb7t trong c\u00e1c t\u1ea3ng \u0111\u00e1 n\u00f3ng v\u00e0 s\u1eed d\u1ee5ng h\u01a1i n\u01b0\u1edbc h\u00ecnh th\u00e0nh \u0111\u1ec3 ch\u1ea1y turbine. C\u00f3 th\u1ec3 c\u00f3 r\u1ea5t nhi\u1ec1u c\u01a1 h\u1ed9i cho c\u00e1ch khai th\u00e1c n\u00e0y, ch\u1ec9 c\u1ea7n ch\u00ednh ph\u1ee7 c\u00f3 th\u1ec3 b\u1ecb thuy\u1ebft ph\u1ee5c \u0111\u1ec3 nh\u00ecn nh\u1eadn n\u00f3 m\u1ed9t c\u00e1ch nghi\u00eam t\u00fac. 50 Ng\u01b0\u1eddi ta s\u1ebd c\u00e2n nh\u1eb9 \u0111i bao nhi\u00eau khi \u1edf v\u00f9ng x\u00edch \u0111\u1ea1o? N\u1ebfu b\u1ea1n mu\u1ed1n gi\u1ea3m c\u00e2n t\u1ee9c th\u00ec v\u00e0 c\u1ea3m th\u1ea5y th\u00fa v\u1ecb tho\u1ea3i m\u00e1i trong th\u1eddi gian gi\u1ea3m c\u00e2n \u0111\u00f3 th\u00ec h\u00e3y l\u00ean m\u1ed9t chuy\u1ebfn bay t\u1edbi Singapore hay Quito. N\u1eb1m g\u1ea7n \u0111\u01b0\u1eddng x\u00edch \u0111\u1ea1o, nh\u1eefng th\u00e0nh ph\u1ed1 n\u00e0y g\u00e1nh ch\u1ecbu h\u1ea7u h\u1ebft hi\u1ec7u \u1ee9ng ly t\u00e2m ho\u00e0n to\u00e0n c\u1ee7a s\u1ef1 xoay tr\u00e1i \u0111\u1ea5t, l\u00e0m gi\u1ea3m \u0111i l\u1ef1c hi\u1ec7u d\u1ee5ng 68 https:\/\/thuviensach.vn","c\u1ee7a tr\u1ecdng l\u1ef1c. C\u00e1c th\u00e0nh ph\u1ed1 n\u00e0y c\u0169ng h\u01b0\u1edfng l\u1ee3i gi\u00e1n ti\u1ebfp t\u1eeb m\u1ed9t hi\u1ec7n t\u01b0\u1ee3ng l\u00e0 t\u00e1c \u0111\u1ed9ng ly t\u00e2m c\u0169ng l\u00e0m cho tr\u00e1i \u0111\u1ea5t ph\u00ecnh ra m\u1ed9t ch\u00fat \u1edf \u0111\u01b0\u1eddng x\u00edch \u0111\u1ea1o, do \u0111\u00f3 ch\u00fang c\u0169ng c\u00e1ch xa h\u01a1n kho\u1ea3ng 12km t\u00ednh t\u1eeb t\u00e2m tr\u00e1i \u0111\u1ea5t, c\u1eaft gi\u1ea3m nhi\u1ec1u h\u01a1n n\u1eefa c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a tr\u1ecdng l\u1ef1c. \u0110\u00e1ng bu\u1ed3n l\u00e0 ngay c\u1ea3 hi\u1ec7u \u1ee9ng c\u1ed9ng h\u1ee3p c\u1ee7a c\u1ea3 hai hi\u1ec7u \u1ee9ng tr\u00ean c\u0169ng kh\u00f4ng gi\u00fap gi\u1ea3m c\u00e2n h\u01a1n bao nhi\u00eau: kho\u1ea3ng 0,3% so v\u1edbi v\u01b0\u01a1ng qu\u1ed1c Anh. N\u00f3i c\u00e1ch kh\u00e1c, m\u1ed9t ng\u01b0\u1eddi 60 k\u00fd \u1edf London s\u1ebd c\u00e2n nh\u1eb9 h\u01a1n kho\u1ea3ng 200g \u1edf Singapore. C\u00f3 l\u1ebd c\u00e1ch gi\u1ea3m c\u00e2n r\u1ebb h\u01a1n l\u00e0 ch\u1ec9 c\u1ea7n b\u1ecf m\u1ed9t b\u1eefa \u0103n tr\u01b0a. V\u00ec ozone l\u00e0 kh\u00ed, b\u1eb1ng c\u00e1ch 51 n\u00e0o m\u00e0 m\u1ed9t th\u1ee9 \u0111\u01b0\u1ee3c cho l\u00e0 \u201cl\u1ed7 th\u1ee7ng\u201d c\u00f3 th\u1ec3 xu\u1ea5t hi\u1ec7n? Ozone th\u1ef1c ch\u1ea5t l\u00e0 kh\u00ed v\u00e0 \u0111\u1ea3m nhi\u1ec7m m\u1ed9t ch\u1ee9c n\u0103ng s\u1ed1ng c\u00f2n l\u00e0 che ch\u1eafn ch\u00fang ta kh\u1ecfi nh\u1eefng d\u1ea1ng b\u1ee9c x\u1ea1 c\u1ef1c t\u00edm (tia UV) nguy hi\u1ec3m nh\u1ea5t ph\u00e1t ra t\u1eeb m\u1eb7t tr\u1eddi. C\u1ea5u t\u1ea1o b\u1edfi ba nguy\u00ean t\u1eed oxygen, n\u00f3 \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh \u1edf c\u00e1ch m\u1eb7t \u0111\u1ea5t kho\u1ea3ng 16 t\u1edbi 48 km tr\u00ean t\u1ea7ng b\u00ecnh l\u01b0u b\u1edfi t\u00e1c \u0111\u1ed9ng c\u1ee7a tia UV l\u00ean c\u00e1c ph\u00e2n t\u1eed oxygen, m\u1ed9t s\u1ed1 ph\u00e2n t\u1eed n\u00e0y b\u1ecb ph\u00e1 v\u1ee1 ra v\u00e0 k\u1ebft h\u1ee3p l\u1ea1i d\u01b0\u1edbi d\u1ea1ng nh\u00f3m ba nguy\u00ean t\u1eed. Ozone \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh s\u1ebd b\u1eaft gi\u1eef d\u1ea1ng tia ph\u00f3ng x\u1ea1 c\u00f3 h\u1ea1i nh\u1ea5t, UV-C, nh\u1eefng tia m\u00e0 n\u1ebfu kh\u00f4ng b\u1ecb gi\u1eef l\u1ea1i s\u1ebd g\u00e2y nh\u1eefng t\u1ed5n th\u01b0\u01a1ng nghi\u00eam tr\u1ecdng t\u1edbi c\u00e1c t\u1ebf b\u00e0o s\u1ed1ng. V\u00e0o gi\u1eefa nh\u1eefng n\u0103m 1980, c\u00e1c nh\u00e0 khoa h\u1ecdc c\u1ee7a \u0110\u1ed9i kh\u1ea3o s\u00e1t Nam c\u1ef1c Anh \u0111\u00e3 ph\u00e1t hi\u1ec7n ra r\u1eb1ng n\u1ed3ng 69 https:\/\/thuviensach.vn","\u0111\u1ed9 ozone tr\u00ean kh\u1eafp l\u1ee5c \u0111\u1ecba b\u00e1n c\u1ea7u nam \u0111\u00e3 t\u1ee5t xu\u1ed1ng kho\u1ea3ng 30% trong th\u00e1ng 10. C\u00e1c ph\u00e2n t\u00edch \u0111\u00e3 ch\u1ec9 ra r\u1eb1ng m\u1ed9t v\u00f9ng r\u1ed9ng l\u1edbn ozone \u0111\u00e3 b\u1ecb ph\u00e1 h\u1ee7y, nh\u01b0 th\u1ec3 c\u00f3 m\u1ed9t b\u00e0n tay kh\u1ed5ng l\u1ed3 v\u1edbi xu\u1ed1ng v\u00e0 m\u00fac n\u00f3 \u0111i. V\u1edbi m\u1ee9c \u0111\u1ed9 nh\u01b0 v\u1eady, g\u1ecdi n\u00f3 l\u00e0 m\u1ed9t l\u1ed7 h\u1ed5ng ozone l\u00e0 r\u1ea5t d\u1ec5 hi\u1ec3u, c\u0169ng y nh\u01b0 c\u00e1ch ch\u00fang ta n\u00f3i v\u1ec1 m\u1ed9t c\u00e1i l\u1ed7 tr\u00ean m\u1eb7t \u0111\u1ea5t. C\u00e1c \u0111o l\u01b0\u1eddng sau \u0111\u00f3 \u0111\u00e3 ti\u1ebft l\u1ed9 r\u1eb1ng l\u1ed7 h\u1ed5ng \u0111ang tr\u1edf n\u00ean s\u00e2u h\u01a1n v\u00e0 r\u1ed9ng h\u01a1n, v\u1edbi nh\u1eefng \u00e1m ch\u1ec9 \u0111\u00e1ng lo ng\u1ea1i v\u1ec1 m\u1ee9c \u0111\u1ed9 tia UV \u1edf Nam b\u00e1n c\u1ea7u. C\u00e1c l\u1eddi gi\u1ea3i th\u00edch kh\u00e1c nhau \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u01b0a ra \u0111\u1ec3 gi\u1ea3i th\u00edch s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a n\u00f3, bao g\u1ed3m c\u1ea3 \u00fd t\u01b0\u1edfng r\u1eb1ng m\u1ed9t d\u1ea1ng qu\u00e1i l\u1ea1 n\u00e0o \u0111\u00f3 c\u1ee7a s\u1ef1 tu\u1ea7n ho\u00e0n kh\u00ed quy\u1ec3n \u0111\u00e3 \u0111\u1ea9y ozone \u0111i, gi\u1ed1ng nh\u01b0 ho\u1ea1t \u0111\u1ed9ng c\u1ee7a m\u00e1y s\u1ea5y qu\u1ea7n \u00e1o \u0111\u1ea9y n\u01b0\u1edbc v\u0103ng ra. Nguy\u00ean nh\u00e2n th\u1eadt s\u1ef1 h\u00f3a ra l\u1ea1i l\u00e0 c\u00e1c tinh th\u1ec3 b\u0103ng c\u00f3 nhi\u1ec1u trong kh\u00ed quy\u1ec3n Nam c\u1ef1c, ch\u00fang l\u00e0m t\u0103ng th\u00eam hi\u1ec7u qu\u1ea3 c\u1ee7a c\u00e1c ch\u1ea5t h\u00f3a h\u1ecdc c\u00f4ng nghi\u1ec7p ph\u00e1 h\u1ee7y ozone, ch\u1ea5t CFC. Nh\u1eefng ch\u1ea5t n\u00e0y hi\u1ec7n nay \u0111\u00e3 b\u1ecb c\u1ea5m v\u00e0 c\u00e1c \u0111o \u0111\u1ea1c hi\u1ec7n nay v\u1ec1 l\u1ed7 h\u1ed5ng ozone g\u1ee3i \u00fd r\u1eb1ng n\u00f3 c\u00f3 th\u1ec3 \u0111ang \u0111\u01b0\u1ee3c l\u1ea5p \u0111\u1ea7y l\u1ea1i. 52 Nh\u1eefng \u0111i\u1ec1u ki\u1ec7n tr\u00ean tr\u00e1i \u0111\u1ea5t ph\u1ea3i thay \u0111\u1ed5i t\u1edbi m\u1ee9c n\u00e0o m\u1edbi c\u00f3 th\u1ec3 lo\u1ea1i tr\u1eeb s\u1ef1 s\u1ed1ng? \u0110\u00e2y l\u00e0 m\u1ed9t v\u1ea5n \u0111\u1ec1 ch\u1ee7 ch\u1ed1t trong cu\u1ed9c tranh lu\u1eadn li\u1ec7u s\u1ef1 s\u1ed1ng c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i \u1edf nh\u1eefng n\u01a1i kh\u00e1c trong v\u0169 tr\u1ee5 kh\u00f4ng, r\u1eb1ng n\u1ebfu s\u1ef1 s\u1ed1ng l\u00e0 \u0111\u1eb7c bi\u1ec7t kh\u00f3 t\u00ednh v\u1ec1 c\u00e1c 70 https:\/\/thuviensach.vn","\u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 n\u00f3 c\u00f3 th\u1ec3 ph\u00e1t tri\u1ec3n m\u1ea1nh, kh\u1ea3 n\u0103ng t\u00ecm th\u1ea5y n\u00f3 \u1edf n\u01a1i kh\u00e1c l\u00e0 kh\u00f4ng s\u00e1ng s\u1ee7a g\u00ec. M\u1eb7c d\u00f9 c\u00e1c nh\u00e0 sinh v\u1eadt h\u1ecdc c\u00f3 th\u1ec3 tranh lu\u1eadn v\u00f4 t\u1eadn v\u1ec1 nh\u1eefng g\u00ec l\u00e0 th\u1ef1c s\u1ef1 c\u1ea7n thi\u1ebft, v\u1eabn c\u00f3 m\u1ed9t s\u1ef1 nh\u1ea5t tr\u00ed chung r\u1eb1ng s\u1ef1 s\u1ed1ng tr\u00ean tr\u00e1i \u0111\u1ea5t c\u1ea7n n\u01b0\u1edbc \u1edf d\u1ea1ng l\u1ecfng. \u0110i\u1ec1u n\u00e0y \u0111\u1eb7t ra m\u1ed9t gi\u1edbi h\u1ea1n cho nhi\u1ec7t \u0111\u1ed9 tr\u00e1i \u0111\u1ea5t: qu\u00e1 n\u00f3ng v\u00e0 n\u01b0\u1edbc s\u1ebd b\u1ed1c h\u01a1i, qu\u00e1 l\u1ea1nh v\u00e0 n\u01b0\u1edbc s\u1ebd \u0111\u00f3ng b\u0103ng. \u0110\u1ebfn l\u01b0\u1ee3t \u0111i\u1ec1u n\u00e0y l\u1ea1i \u0111\u1eb7t ra m\u1ed9t gi\u1edbi h\u1ea1n cho kho\u1ea3ng c\u00e1ch c\u00f3 th\u1ec3 c\u1ee7a tr\u00e1i \u0111\u1ea5t so v\u1edbi m\u1eb7t tr\u1eddi; c\u00e1c \u01b0\u1edbc l\u01b0\u1ee3ng hay thay \u0111\u1ed5i nh\u01b0ng ch\u00fang th\u01b0\u1eddng d\u1eabn t\u1edbi m\u1ed9t \u201cV\u00f9ng c\u00f3 kh\u1ea3 n\u0103ng s\u1ed1ng\u201d (Habitability Zone), v\u00f9ng n\u00e0y b\u1eaft \u0111\u1ea7u t\u1eeb c\u00e1c qu\u1ef9 \u0111\u1ea1o nh\u1ecf h\u01a1n c\u1ee7a tr\u00e1i \u0111\u1ea5t kho\u1ea3ng 20% v\u00e0 gi\u00e3n r\u1ed9ng ra l\u1edbn h\u01a1n qu\u1ef9 \u0111\u1ea1o tr\u00e1i \u0111\u1ea5t kho\u1ea3ng 60% - ho\u00e0n to\u00e0n kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t gi\u1edbi h\u1ea1n r\u1ed9ng, ch\u1ec9 v\u1eeba \u0111\u1ee7 \u0111\u1ec3 bao g\u1ed3m sao H\u1ecfa. V\u1edbi m\u1ed9t m\u1eabu ch\u1ec9 c\u00f3 m\u1ed9t h\u00e0nh tinh th\u00ec kh\u00f3 c\u00f3 th\u1ec3 kh\u1eb3ng \u0111\u1ecbnh, nh\u01b0ng v\u1edbi m\u1ed9t m\u1eabu kho\u1ea3ng 100 h\u00e0nh tinh \u0111\u00e3 \u0111\u01b0\u1ee3c ph\u00e1t hi\u1ec7n quanh c\u00e1c ng\u00f4i sao kh\u00e1c cho t\u1edbi hi\u1ec7n nay, v\u1eabn kh\u00f4ng c\u00f3 h\u00e0nh tinh n\u00e0o n\u1eb1m trong v\u00f9ng c\u00f3 kh\u1ea3 n\u0103ng s\u1ed1ng c\u1ee7a ng\u00f4i sao m\u1eb9 c\u1ee7a n\u00f3. B\u1edfi v\u00ec t\u1ea5t c\u1ea3 nh\u1eefng ng\u00f4i sao n\u00e0y \u0111\u1ec1u l\u00e0 c\u00e1c l\u00e1ng gi\u1ec1ng trong v\u0169 tr\u1ee5 c\u1ee7a ch\u00fang ta, v\u1eabn c\u00f2n qu\u00e1 s\u1edbm \u0111\u1ec3 cho ra m\u1ed9t con s\u1ed1 \u0111\u00e1ng tin c\u1eady v\u1ec1 l\u01b0\u1ee3ng h\u00e0nh tinh trong Ng\u00e2n h\u00e0 c\u1ee7a ch\u00fang ta m\u00e0 c\u00f3 th\u1ec3 h\u1ed7 tr\u1ee3 s\u1ef1 s\u1ed1ng (s\u1ef1 s\u1ed1ng theo c\u00e1ch ch\u00fang ta hi\u1ec3u) m\u00e0 c\u00e1c b\u1eb1ng ch\u1ee9ng th\u00ec kh\u00f4ng thuy\u1ebft ph\u1ee5c l\u1eafm. 71 https:\/\/thuviensach.vn","53 C\u00e1c t\u00e1c \u0111\u1ed9ng c\u1ee7a kh\u00ed quy\u1ec3n c\u00f3 th\u1ec3 cho ph\u00e9p m\u1ed9t ng\u01b0\u1eddi nh\u00ecn qua c\u1ea3 \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi kh\u00f4ng? C\u00e1ch th\u00f4ng th\u01b0\u1eddng \u0111\u1ec3 t\u00ednh ra kho\u1ea3ng c\u00e1ch t\u1edbi \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi th\u01b0\u1eddng gi\u1ea3 \u0111\u1ecbnh r\u1eb1ng tr\u00e1i \u0111\u1ea5t l\u00e0 m\u1ed9t qu\u1ea3 c\u1ea7u ho\u00e0n h\u1ea3o, kh\u00f4ng c\u00f3 kh\u00f4ng kh\u00ed m\u00e0 trong tr\u01b0\u1eddng h\u1ee3p \u0111\u00f3 \u00e1nh s\u00e1ng \u0111i theo nh\u1eefng \u0111\u01b0\u1eddng th\u1eb3ng v\u00e0 v\u1edbi m\u1ed9t ch\u00fat t\u00ednh to\u00e1n h\u00ecnh h\u1ecdc \u0111\u00e3 ch\u1ec9 ra r\u1eb1ng kho\u1ea3ng c\u00e1ch m\u00e0 ch\u00fang ta c\u00f3 th\u1ec3 nh\u00ecn th\u1ea5y \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1eb1ng c\u00f4ng th\u1ee9c sau: l\u1ea5y \u0111\u1ed9 cao so v\u1edbi m\u1ef1c n\u01b0\u1edbc bi\u1ec3n c\u1ee7a n\u01a1i b\u1ea1n \u0111\u1ee9ng (t\u00ednh b\u1eb1ng \u0111\u01a1n v\u1ecb b\u1ed9) c\u1ed9ng th\u00eam 50% r\u1ed3i l\u1ea5y c\u0103n b\u1eadc hai; k\u1ebft qu\u1ea3 ch\u00ednh l\u00e0 kho\u1ea3ng c\u00e1ch t\u1edbi \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi t\u00ednh b\u1eb1ng d\u1eb7m. V\u1edbi c\u00e1ch t\u00ednh n\u00e0y, m\u1ed9t ng\u01b0\u1eddi cao 6 b\u1ed9 (1,8m) \u0111\u1ee9ng \u1edf m\u1ef1c n\u01b0\u1edbc bi\u1ec3n c\u00f3 th\u1ec3 nh\u00ecn xa 3 d\u1eb7m (4,8km). Tuy nhi\u00ean, c\u00e1ch t\u00ednh n\u00e0y \u0111\u00e3 lo\u1ea1i tr\u1eeb kh\u00ed quy\u1ec3n tr\u00e1i \u0111\u1ea5t, m\u1ed9t y\u1ebfu t\u1ed1 l\u00e0m cong tia s\u00e1ng v\u00e0 nh\u00ecn chung, c\u00f3 th\u1ec3 cho ph\u00e9p ch\u00fang ta nh\u00ecn xa h\u01a1n ph\u1ea7n n\u00e0o \u0111\u00f3. V\u00ec kh\u1ea3 n\u0103ng l\u00e0m cong tia s\u00e1ng c\u1ee7a kh\u00f4ng kh\u00ed \u1edf m\u1ef1c n\u01b0\u1edbc bi\u1ec3n kh\u00e1c bi\u1ec7t 0,003% so v\u1edbi c\u1ee7a ch\u00e2n kh\u00f4ng, n\u00f3 h\u1ea7u nh\u01b0 kh\u00f4ng \u0111\u00e1ng c\u1ed9ng v\u00e0o. Tuy nhi\u00ean, th\u1eadt \u0111\u00e1ng kinh ng\u1ea1c, c\u00e1c t\u00ednh to\u00e1n chi ti\u1ebft l\u1ea1i ch\u1ec9 ra r\u1eb1ng hi\u1ec7u \u1ee9ng kh\u00fac x\u1ea1 n\u00e0y cho ph\u00e9p \u00e1nh s\u00e1ng \u0111\u1ebfn \u0111\u01b0\u1ee3c ch\u00fang ta t\u1eeb kho\u1ea3ng c\u00e1ch xa h\u01a1n kho\u1ea3ng 10% so v\u1edbi k\u1ebft qu\u1ea3 c\u1ee7a c\u00f4ng th\u1ee9c \u0111\u01a1n gi\u1ea3n. N\u00f3i c\u00e1ch kh\u00e1c, kh\u00ed quy\u1ec3n th\u1ef1c s\u1ef1 l\u00e0m t\u0103ng chi\u1ec1u cao c\u1ee7a ch\u00fang ta l\u00ean kho\u1ea3ng 20% khi ch\u00fang ta nh\u00ecn xa v\u1ec1 ch\u00e2n tr\u1eddi, v\u00ec v\u1eady n\u1ebfu \u0111\u1ee9ng t\u1eeb m\u1ed9t \u0111\u1ec9nh n\u00fai cao 3.000 72 https:\/\/thuviensach.vn","b\u1ed9 (915m), ch\u00fang ta c\u00f3 th\u1ec3 nh\u00ecn \u201cqua c\u1ea3 \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi\u201d th\u00eam kho\u1ea3ng 5 d\u1eb7m (8km) n\u1eefa. 54 Mu\u1ed1i \u1edf bi\u1ec3n t\u1eeb \u0111\u00e2u t\u1edbi v\u00e0 n\u00f3 c\u00f3 \u0111ang ti\u1ebfp t\u1ee5c t\u00edch t\u1ee5 l\u1ea1i n\u1eefa kh\u00f4ng? Bi\u1ec3n c\u1ea3 ch\u1ee9a r\u1ea5t nhi\u1ec1u h\u1ee3p ch\u1ea5t b\u1ecb c\u00e1c c\u01a1n m\u01b0a r\u1eeda tr\u00f4i sau khi h\u00f2a tan c\u00e1c ch\u1ea5t h\u00f3a h\u1ecdc trong c\u00e1c t\u1ea3ng \u0111\u00e1 l\u1ed9 thi\u00ean. Ho\u00e0n to\u00e0n t\u1ef1 nhi\u00ean, nh\u1eefng ch\u1ea5t c\u00f3 nhi\u1ec1u kh\u1ea3 n\u0103ng nh\u1ea5t \u0111\u1ec3 \u0111\u1ebfn \u0111\u01b0\u1ee3c bi\u1ec3n ch\u00ednh l\u00e0 nh\u1eefng ch\u1ea5t tan trong n\u01b0\u1edbc nhi\u1ec1u nh\u1ea5t, \u0111\u00f3 l\u00e0 Cl v\u00e0 Na - th\u00e0nh ph\u1ea7n c\u0103n b\u1ea3n c\u1ee7a mu\u1ed1i th\u01b0\u1eddng; ch\u00fang chi\u1ebfm t\u1edbi g\u1ea7n 90% t\u1ea5t c\u1ea3 c\u00e1c h\u1ee3p ch\u1ea5t h\u00f2a tan \u1edf trong bi\u1ec3n. Qua nhi\u1ec1u tri\u1ec7u n\u0103m, qu\u00e1 tr\u00ecnh x\u00f3i m\u00f2n \u0111\u00e3 k\u00e9o m\u1ed9t l\u01b0\u1ee3ng mu\u1ed1i t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi kho\u1ea3ng b\u1ed1n th\u00eca u\u1ed1ng tr\u00e0 \u0111\u1ea7y v\u00e0o trong m\u1ed7i n\u1eeda l\u00edt n\u01b0\u1edbc bi\u1ec3n - m\u1ed9t n\u1ed3ng \u0111\u1ed9 m\u00e0 n\u1ebfu \u0111\u01b0\u1ee3c chi\u1ebft t\u00e1ch ra kh\u1ecfi t\u1ea5t c\u1ea3 c\u00e1c \u0111\u1ea1i d\u01b0\u01a1ng th\u00ec s\u1ebd t\u1ea1o ra m\u1ed9t l\u1edbp mu\u1ed1i d\u1ea7y 45m. Nghe c\u00f3 v\u1ebb r\u1ea5t nhi\u1ec1u, nh\u01b0ng c\u00e1c t\u00ednh to\u00e1n l\u00f9i tr\u1edf l\u1ea1i c\u00f2n g\u1ee3i \u00fd r\u1eb1ng c\u00f3 l\u1ebd hi\u1ec7n gi\u1edd bi\u1ec3n \u0111\u00e3 ho\u00e0n to\u00e0n b\u00e3o h\u00f2a v\u1edbi mu\u1ed1i - v\u00e0 c\u0169ng ch\u1ebft ch\u00f3c nh\u01b0 bi\u1ec3n Ch\u1ebft. \u0110\u01b0\u01a1ng nhi\u00ean l\u00e0 \u0111i\u1ec1u \u0111\u00f3 kh\u00f4ng x\u1ea3y ra, cho n\u00ean \u0111i\u1ec1u b\u00ed \u1ea9n kh\u00f4ng ph\u1ea3i l\u00e0 t\u1ea1i sao bi\u1ec3n l\u1ea1i m\u1eb7n m\u00e0 l\u00e0 t\u1ea1i sao n\u00f3 l\u1ea1i kh\u00f4ng b\u1ecb b\u00e3o h\u00f2a mu\u1ed1i? M\u1ed9t l\u1eddi gi\u1ea3i th\u00edch \u0111\u01b0\u1ee3c \u0111\u01b0a ra v\u00e0o nh\u1eefng n\u0103m 1970, b\u1edfi m\u1ed9t nh\u00e0 sinh th\u00e1i h\u1ecdc kh\u00e1 n\u1ed5i ti\u1ebfng James Lovelock 73 https:\/\/thuviensach.vn","b\u1eb1ng vi\u1ec7c ph\u00e1t tri\u1ec3n \u201cgi\u1ea3 thuy\u1ebft Gaia\u201d c\u1ee7a \u00f4ng, m\u00e0 theo \u0111\u00f3 nh\u1eefng c\u01a1 th\u1ec3 s\u1ed1ng t\u01b0\u01a1ng t\u00e1c v\u1edbi tr\u00e1i \u0111\u1ea5t b\u1eb1ng nhi\u1ec1u c\u00e1ch gi\u00fap gi\u1eef cho h\u00e0nh tinh n\u00e0y v\u1eabn lu\u00f4n th\u00edch h\u1ee3p cho s\u1ef1 s\u1ed1ng. N\u1ed3ng \u0111\u1ed9 mu\u1ed1i qu\u00e1 cao s\u1ebd ra m\u1ed9t m\u1ed1i \u0111e do\u1ea1 h\u1ee7y di\u1ec7t cho s\u1ef1 s\u1ed1ng d\u01b0\u1edbi bi\u1ec3n v\u00e0 Lovelock t\u1ef1 h\u1ecfi li\u1ec7u c\u00f3 m\u1ed9t s\u1ed1 sinh v\u1eadt c\u00f3 th\u1ec3 gi\u1eef \u1ed5n \u0111\u1ecbnh n\u1ed3ng \u0111\u1ed9 mu\u1ed1i b\u1ea5t ch\u1ea5p s\u1ef1 x\u00f3i m\u00f2n \u0111\u1ea5t li\u1ec1n to\u00e0n c\u1ea7u hay kh\u00f4ng. \u00d4ng \u0111\u00e3 t\u00ecm ra m\u1ed9t \u1ee9ng c\u1eed vi\u00ean trong c\u00e1c lo\u00e0i vi sinh v\u1eadt nguy\u00ean sinh ch\u1ecbu tr\u00e1ch nhi\u1ec7m t\u1ea1o ra c\u00e1c ph\u00e1 c\u1ea1n kh\u1ed5ng l\u1ed3 \u1edf c\u00e1c v\u00f9ng b\u1edd bi\u1ec3n nh\u01b0 Baja California (ph\u00e1 l\u00e0 m\u1ed9t c\u00e1i h\u1ed3 b\u1ecb ng\u0103n c\u00e1ch v\u1edbi bi\u1ec3n b\u1edfi m\u1ed9t d\u1ea3i \u0111\u00e1 ng\u1ea7m hay c\u00e1t). Nhi\u1ec7t l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi tr\u00ean c\u00e1c ph\u00e1 n\u00e0y l\u00e0m n\u01b0\u1edbc b\u1ed1c h\u01a1i \u0111i khi\u1ebfn mu\u1ed1i b\u1ecb l\u1eafng l\u1ea1i t\u1ea1i \u0111\u00e2y, sau \u0111\u00f3 n\u01b0\u1edbc bi\u1ec3n l\u1ea1i ch\u1ea3y v\u00e0o v\u00e0 qu\u00e1 tr\u00ecnh \u0111\u01b0\u1ee3c l\u1eb7p l\u1ea1i. Kh\u00f4ng th\u1ec3 bi\u1ebft \u0111\u01b0\u1ee3c qu\u00e1 tr\u00ecnh n\u00e0y c\u00f3 \u0111\u1ee7 s\u1ee9c m\u1ea1nh \u0111\u1ec3 gi\u1eef nguy\u00ean \u0111\u1ed9 m\u1eb7n c\u1ee7a bi\u1ec3n hay kh\u00f4ng, nh\u01b0ng n\u00f3 v\u1eabn l\u00e0 m\u1ed9t gi\u1ea3i \u0111\u00e1p h\u1ea5p d\u1eabn thay v\u00ec ph\u1ea3i ch\u1ea5p nh\u1eadn m\u1ed9t b\u00ed \u1ea9n th\u1eadt kh\u00f3 ch\u1ecbu. M\u00e1y bay Concorde \u0111\u00e3 bay 55 b\u00ean cao h\u01a1n kh\u00ed quy\u1ec3n bao nhi\u00eau ph\u1ea7n tr\u0103m ? Nh\u1eefng ng\u01b0\u1eddi say m\u00ea chi\u1ebfc phi c\u01a1 si\u00eau thanh qu\u00e1 c\u1ed1 th\u01b0\u1eddng nh\u1ea5n m\u1ea1nh t\u1edbi t\u1ed1c \u0111\u1ed9 bay v\u00f4 \u0111\u1ecbch th\u1ebf gi\u1edbi c\u1ee7a n\u00f3, h\u01a1n 600m\/s. Nh\u01b0ng \u0111\u1ed9 cao m\u00e0 n\u00f3 bay c\u0169ng kh\u00f4ng k\u00e9m ph\u1ea7n g\u00e2y s\u1eedng s\u1ed1t, h\u01a1n 18 km, g\u1ea7n g\u1ea5p hai l\u1ea7n \u0111\u1ed9 74 https:\/\/thuviensach.vn","bay cao c\u1ee7a c\u00e1c phi c\u01a1 h\u00e0nh kh\u00e1ch th\u00f4ng th\u01b0\u1eddng; \u0111\u1ee7 cao \u0111\u1ec3 nh\u00ecn th\u1ea5y \u0111\u1ed9 cong c\u1ee7a tr\u00e1i \u0111\u1ea5t. Kh\u1ea3 n\u0103ng bay n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0a Concorde v\u00e0o t\u1ea7ng b\u00ecnh l\u01b0u, cao h\u01a1n b\u1ea7u kh\u00ed quy\u1ec3n kho\u1ea3ng 85%, n\u01a1i m\u00e0 m\u1eadt \u0111\u1ed9 kh\u00f4ng kh\u00ed ch\u1ec9 c\u00f2n b\u1eb1ng 1\/3 so v\u1edbi m\u1eadt \u0111\u1ed9 t\u1ea1i \u0111\u1ed9 cao c\u1ee7a c\u00e1c ph\u1ea3n l\u1ef1c c\u01a1 th\u00f4ng th\u01b0\u1eddng. 75 https:\/\/thuviensach.vn","TR\u00caN THI\u00caN \u0110\u00c0NG 56 Kh\u00f4ng gian \u0111\u01b0\u1ee3c t\u00ednh t\u1eeb \u0111\u00e2u? H\u01a1n 40 n\u0103m sau khi c\u00e1c phi h\u00e0nh gia b\u1eaft \u0111\u1ea7u th\u00e1m hi\u1ec3m kh\u00f4ng gian, v\u1eabn kh\u00f4ng c\u00f3 m\u1ed9t \u0111\u1ecbnh ngh\u0129a \u0111\u01b0\u1ee3c ch\u1ea5p nh\u1eadn r\u1ed9ng r\u00e3i r\u1eb1ng n\u00f3 b\u1eaft \u0111\u1ea7u t\u1eeb \u0111\u00e2u. NASA t\u1eeb l\u00e2u \u0111\u00e3 c\u00f3 m\u1ed9t truy\u1ec1n th\u1ed1ng trao th\u01b0\u1edfng cho b\u1ea5t k\u1ef3 ai \u0111\u1ebfn \u0111\u01b0\u1ee3c \u0111\u1ed9 cao 80km, ch\u1ee9ng t\u1ecf r\u1eb1ng h\u1ecd \u0111\u00e3 t\u1eebng v\u00e0o kh\u00f4ng gian. Trong nh\u1eefng n\u0103m 1960, t\u00e1m phi c\u00f4ng c\u1ee7a t\u00ean l\u1eeda th\u00ed nghi\u1ec7m X-15 \u0111\u00e3 c\u00f9ng v\u1edbi c\u00e1c phi h\u00e0nh gia c\u1ee7a ch\u01b0\u01a1ng tr\u00ecnh Apollo, Gemini, Mecury nh\u1eadn gi\u1ea3i th\u01b0\u1edfng v\u1edbi phi c\u00f4ng Joe Walker, ng\u01b0\u1eddi \u0111\u00e3 \u0111\u1ea1t t\u1edbi \u0111\u1ed9 cao 100km trong hai chuy\u1ebfn bay v\u00e0o n\u0103m 1963. H\u1ea7u h\u1ebft c\u00e1c chuy\u00ean gia kh\u00f4ng gian \u0111\u1ed3ng \u00fd v\u1edbi \u0111\u1ed9 cao 100km n\u00e0y, t\u1ea1o th\u00e0nh m\u1ed9t chuy\u1ebfn du h\u00e0nh kh\u00f4ng gian th\u1ef1c s\u1ef1 v\u00e0 n\u00f3 c\u00f2n c\u00f3 th\u1ec3 tr\u1edf th\u00e0nh m\u1ed9t ti\u00eau chu\u1ea9n ph\u00e1p l\u00fd: n\u0103m 2002, n\u01b0\u1edbc \u00dac tr\u1edf th\u00e0nh n\u01b0\u1edbc \u0111\u1ea7u ti\u00ean ch\u1ea5p nh\u1eadn 100km l\u00e0 \u0111i\u1ec3m kh\u00f4ng gian b\u1eaft \u0111\u1ea7u. 76 https:\/\/thuviensach.vn","57 T\u1ea1i sao ch\u00fang ta kh\u00f4ng c\u1ea3m nh\u1eadn \u0111\u01b0\u1ee3c chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a tr\u00e1i \u0111\u1ea5t khi ch\u00fang ta quay quanh m\u1eb7t tr\u1eddi? \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 kh\u00f3 tin nh\u01b0ng t\u1ea5t c\u1ea3 ch\u00fang ta \u0111\u1ec1u \u0111ang bay r\u1ea5t nhanh xung quanh m\u1eb7t tr\u1eddi v\u1edbi v\u1eadn t\u1ed1c 30km\/s m\u00e0 kh\u00f4ng c\u00f3 m\u1ed9t ph\u01b0\u01a1ng ti\u1ec7n n\u00e2ng \u0111\u1ee1 r\u00f5 r\u00e0ng n\u00e0o. L\u00fd do m\u00e0 ch\u00fang ta kh\u00f4ng nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c chuy\u1ec7n n\u00e0y l\u00e0: v\u1eadn t\u1ed1c kh\u00f4ng ph\u1ea3i l\u00e0 th\u1ee9 cho ch\u00fang ta c\u1ea3m gi\u00e1c v\u1ec1 chuy\u1ec3n \u0111\u1ed9ng m\u00e0 \u0111\u00fang ra l\u00e0 s\u1ef1 thay \u0111\u1ed5i v\u1eadn t\u1ed1c - t\u1ee9c l\u00e0 gia t\u1ed1c. \u0110\u00fang l\u00e0 khi ch\u00fang ta bay theo qu\u1ef9 \u0111\u1ea1o quanh m\u1eb7t tr\u1eddi, t\u1ed1c \u0111\u1ed9 c\u1ee7a ch\u00fang ta l\u00e0 kh\u00f4ng \u0111\u1ed5i nh\u01b0ng h\u01b0\u1edbng c\u1ee7a ch\u00fang ta th\u00ec thay \u0111\u1ed5i li\u00ean t\u1ee5c, t\u1ea1o ra m\u1ed9t gia t\u1ed1c; nh\u01b0ng b\u00e1n k\u00ednh c\u1ee7a qu\u1ef9 \u0111\u1ea1o n\u00e0y l\u1ea1i t\u1edbi 150 tri\u1ec7u km, qu\u00e1 l\u1edbn \u0111\u1ebfn n\u1ed7i ngay c\u1ea3 khi di chuy\u1ec3n \u1edf t\u1ed1c \u0111\u1ed9 \u0111\u00f3, gia t\u1ed1c c\u1ee7a ch\u00fang ta nh\u1ecf h\u01a1n t\u1edbi 1.700 l\u1ea7n so v\u1edbi gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng, th\u1ee9 \u0111ang gi\u1eef ch\u00fang ta l\u1ea1i tr\u00ean b\u1ec1 m\u1eb7t tr\u00e1i \u0111\u1ea5t. V\u00e0 nh\u01b0 th\u1ebf l\u00e0 qu\u00e1 nh\u1ecf \u0111\u1ec3 ch\u00fang ta c\u00f3 th\u1ec3 nh\u1eadn th\u1ea5y. 77 https:\/\/thuviensach.vn","58 T\u1ea1i sao m\u1eb7t tr\u0103ng c\u00f3 v\u1ebb l\u1edbn h\u01a1n khi n\u00f3 \u1edf tr\u00ean \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi? Th\u01b0\u1eddng \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u201c\u1ea3o gi\u00e1c m\u1eb7t tr\u0103ng\u201d, \u0111i\u1ec1u n\u00e0y \u0111\u00e3 lu\u00f4n th\u00e1ch \u0111\u1ed1 con ng\u01b0\u1eddi, \u00edt nh\u1ea5t l\u00e0 t\u1eeb th\u1eddi Aristotle. Nhi\u1ec1u ng\u01b0\u1eddi nghi ng\u1edd r\u1eb1ng n\u00f3 l\u00e0 k\u1ebft qu\u1ea3 c\u1ee7a s\u1ef1 kh\u00fac x\u1ea1 khi \u00e1nh tr\u0103ng \u0111i xuy\u00ean qua ph\u1ea7n d\u00e0y h\u01a1n c\u1ee7a kh\u00ed quy\u1ec3n. Nh\u01b0ng m\u1eb7c d\u00f9 kh\u00fac x\u1ea1 c\u00f3 th\u1ec3 c\u00f3 m\u1ed9t v\u00e0i t\u00e1c \u0111\u1ed9ng, n\u00f3 c\u00f3 xu h\u01b0\u1edbng ch\u1ee7 y\u1ebfu l\u00e0 song song v\u1edbi \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi, t\u1ea1o ra hi\u1ec7u \u1ee9ng n\u00e9n kh\u00e1 quen thu\u1ed9c trong c\u00e1c b\u1ee9c \u1ea3nh bu\u1ed5i ho\u00e0ng h\u00f4n. N\u1ebfu b\u1ea1n th\u1ef1c s\u1ef1 \u0111o k\u00edch th\u01b0\u1edbc c\u1ee7a m\u1eb7t tr\u0103ng khi n\u00f3 \u0111ang \u1edf tr\u00ean \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi v\u00e0 khi \u1edf tr\u00ean \u0111\u1ea7u, b\u1ea1n s\u1ebd th\u1ea5y n\u00f3 c\u0169ng g\u1ea7n nh\u01b0 v\u1eady, ch\u1ee9ng t\u1ecf r\u1eb1ng ch\u00fang ta ch\u1ec9 \u0111ang ch\u1ee9ng ki\u1ebfn m\u1ed9t \u1ea3o gi\u00e1c, kh\u00f4ng ph\u1ea3i s\u1ef1 th\u1eadt. L\u1eddi gi\u1ea3i th\u00edch \u0111\u01b0\u1ee3c n\u00eau ra ph\u1ed5 bi\u1ebfn nh\u1ea5t t\u1eadp trung v\u00e0o m\u1ed9t hi\u1ec7u \u1ee9ng th\u1ecb gi\u00e1c, l\u1ea7n \u0111\u1ea7u ti\u00ean \u0111\u01b0\u1ee3c ch\u1ec9 ra b\u1edfi Mario Ponzo, m\u1ed9t nh\u00e0 t\u00e2m l\u00fd h\u1ecdc nh\u1eadn th\u1ee9c, v\u00e0o n\u0103m 1913. Khi ch\u00fang ta nh\u00ecn ra xa, c\u00e1c \u0111\u01b0\u1eddng th\u1eb3ng song song ch\u1eb3ng h\u1ea1n nh\u01b0 c\u00e1c \u0111\u01b0\u1eddng ray xe l\u1eeda hay c\u00e1c con \u0111\u01b0\u1eddng d\u01b0\u1eddng nh\u01b0 h\u1ed9i t\u1ee5 l\u1ea1i \u1edf \u201c\u0111i\u1ec3m bi\u1ebfn m\u1ea5t\u201d nh\u01b0 th\u1ec3 ch\u00fang b\u1ecb bi\u1ebfn m\u1ea5t v\u00e0 do \u0111\u00f3 ch\u00fang ta c\u00f3 khuynh h\u01b0\u1edbng ngh\u0129 r\u1eb1ng nh\u1eefng v\u1eadt th\u1ec3 \u1edf g\u1ea7n \u201c\u0111i\u1ec3m bi\u1ebfn m\u1ea5t\u201d nh\u01b0 \u0111ang \u0111i xa ra. H\u01a1n n\u1eefa, nh\u1eefng v\u1eadt \u1edf xa ph\u1ea3i tr\u00f4ng nh\u1ecf h\u01a1n b\u00ecnh th\u01b0\u1eddng; theo Ponzo, 78 https:\/\/thuviensach.vn","\u0111i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 g\u00e2y ra v\u1ea5n \u0111\u1ec1 khi ch\u00fang ta nh\u00ecn m\u1ed9t v\u1eadt g\u00ec \u0111\u00f3 m\u00e0 ch\u00fang ta ngh\u0129 r\u1eb1ng n\u00f3 \u1edf xa h\u01a1n nh\u01b0ng n\u00f3 l\u1ea1i kh\u00f4ng thay \u0111\u1ed5i k\u00edch th\u01b0\u1edbc. \u0110\u00e2y c\u0169ng ch\u00ednh l\u00e0 nh\u1eefng g\u00ec \u0111\u00e3 x\u1ea3y ra v\u1edbi m\u1eb7t tr\u0103ng: k\u00edch th\u01b0\u1edbc v\u00e0 kho\u1ea3ng c\u00e1ch c\u1ee7a n\u00f3 t\u1edbi ch\u00fang ta g\u1ea7n nh\u01b0 kh\u00f4ng \u0111\u1ed5i nh\u01b0ng khi n\u00f3 c\u00f3 v\u1ebb g\u1ea7n v\u1edbi \u201c\u0111i\u1ec3m bi\u1ebfn m\u1ea5t\u201d, b\u1ed9 n\u00e3o quy\u1ebft \u0111\u1ecbnh r\u1eb1ng n\u00f3 ph\u1ea3i \u0111ang \u1edf xa v\u00e0 do \u0111\u00f3 b\u1ecb \u00e9p ph\u1ea3i k\u1ebft lu\u1eadn r\u1eb1ng l\u00fd do m\u00e0 n\u00f3 v\u1eabn chi\u1ebfm m\u1ed9t v\u00f9ng tr\u1eddi nh\u01b0 c\u0169 (c\u00f3 m\u1ed9t k\u00edch th\u01b0\u1edbc kh\u00f4ng \u0111\u1ed5i) l\u00e0 b\u1edfi v\u00ec n\u00f3 \u0111\u00e3 gi\u00e3n r\u1ed9ng ra. Khi n\u00f3i nh\u01b0 v\u1eady, l\u00fd thuy\u1ebft c\u1ee7a Ponzo c\u0169ng kh\u00f4ng gi\u1ea3i th\u00edch r\u00f5 r\u00e0ng \u0111\u01b0\u1ee3c t\u1ea1i sao c\u00e1c phi c\u00f4ng b\u00ean tr\u00ean c\u00e1c t\u1ea7ng m\u00e2y, kh\u00f4ng th\u1ec3 nh\u00ecn th\u1ea5y b\u1ea5t c\u1ee9 \u201c\u0111i\u1ec3m bi\u1ebfn m\u1ea5t\u201d n\u00e0o, v\u1eabn tr\u00f4ng th\u1ea5y m\u1eb7t tr\u0103ng c\u00f3 v\u1ebb l\u1edbn h\u01a1n khi n\u00f3 t\u1edbi g\u1ea7n \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi. C\u00f3 l\u1ebd \u201c\u1ea3o gi\u00e1c m\u1eb7t tr\u0103ng\u201d h\u00ecnh th\u00e0nh l\u00e0 v\u00ec khi nh\u00ecn th\u1ea5y m\u1ed9t v\u1eadt th\u1ec3 tr\u00ean \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi khi\u1ebfn ta ngh\u0129 n\u00f3 \u1edf xa h\u01a1n l\u00e0 n\u1ebfu n\u00f3 \u0111ang \u1edf tr\u00ean \u0111\u1ea7u. Ch\u1ec9 \u0111i\u1ec1u n\u00e0y c\u0169ng s\u1ebd \u0111\u00e1nh l\u1eeba b\u1ed9 n\u00e3o ch\u00fang ta r\u1eb1ng m\u1eb7t tr\u0103ng tr\u00ean \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi th\u00ec \u1edf xa h\u01a1n b\u00ecnh th\u01b0\u1eddng v\u00e0 do \u0111\u00f3 \u1eaft h\u1eb3n l\u00e0 n\u00f3 \u0111\u00e3 gi\u00e3n r\u1ed9ng. T\u1ea1i sao t\u1ea5t c\u1ea3 c\u00e1c h\u00e0nh tinh 59 \u0111\u1ec1u c\u00f3 h\u00ecnh c\u1ea7u? H\u00ecnh d\u1ea1ng c\u1ee7a m\u1ed9t v\u1eadt th\u1ec3 l\u00e0 k\u1ebft qu\u1ea3 c\u1ee7a nhi\u1ec1u l\u1ef1c kh\u00e1c nhau t\u00e1c \u0111\u1ed9ng l\u00ean n\u00f3. \u0110\u1ed1i v\u1edbi c\u00e1c h\u00e0nh tinh, kh\u1ed1i l\u01b0\u1ee3ng kh\u1ed5ng l\u1ed3 c\u1ee7a n\u00f3 \u0111\u00e3 khi\u1ebfn cho tr\u1ecdng l\u1ef1c tr\u1edf th\u00e0nh l\u1ef1c quan tr\u1ecdng nh\u1ea5t. B\u1eb1ng vi\u1ec7c k\u00e9o c\u00e1c v\u1eadt ch\u1ea5t l\u1ea1i v\u1edbi 79 https:\/\/thuviensach.vn","nhau v\u1edbi m\u1ed9t l\u1ef1c m\u1ea1nh nh\u01b0 nhau \u1edf c\u00e1c kho\u1ea3ng c\u00e1ch b\u1eb1ng nhau t\u1eeb trung t\u00e2m c\u1ee7a h\u00e0nh tinh, tr\u1ecdng l\u1ef1c t\u1ea1o n\u00ean m\u1ed9t s\u1ea3n ph\u1ea9m cu\u1ed1i c\u00f3 h\u00ecnh c\u1ea7u - hay c\u00e0ng gi\u1ed1ng h\u00ecnh c\u1ea7u n\u1ebfu n\u00f3 c\u00e0ng kh\u1ed1ng ch\u1ebf \u0111\u01b0\u1ee3c s\u1ef1 hi\u1ec7n di\u1ec7n c\u1ee7a c\u00e1c l\u1ef1c kh\u00e1c, bao g\u1ed3m c\u1ea3 c\u00e1c l\u1ef1c li\u00ean nguy\u00ean t\u1eed b\u00ean trong v\u1eadt ch\u1ea5t t\u1ea1o th\u00e0nh h\u00e0nh tinh, th\u1ee9 ch\u1ed1ng l\u1ea1i c\u00e1c l\u1ef1c h\u01b0\u1edbng v\u00e0o trong c\u1ee7a tr\u1ecdng l\u1ef1c v\u00e0 c\u00e1c t\u00e1c \u0111\u1ed9ng c\u1ee7a nhi\u1ec7t hay b\u1ea5t k\u1ef3 s\u1ef1 xoay n\u00e0o. K\u1ebft qu\u1ea3 cu\u1ed1i c\u00f9ng th\u01b0\u1eddng kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t h\u00ecnh c\u1ea7u ho\u00e0n h\u1ea3o. V\u00ed d\u1ee5, s\u1ef1 xoay h\u00e0ng ng\u00e0y c\u1ee7a tr\u00e1i \u0111\u1ea5t \u0111\u00e3 khi\u1ebfn \u0111\u01b0\u1eddng x\u00edch \u0111\u1ea1o gi\u00e3n ra, r\u1ed9ng h\u01a1n 44km so v\u1edbi b\u00e1n k\u00ednh \u1edf c\u00e1c c\u1ef1c. H\u01a1n n\u1eefa c\u00f2n c\u00f3 c\u00e1c ch\u1ed7 l\u1ed3i v\u00e0 tr\u0169ng b\u1ecb \u0111\u1ec3 l\u1ea1i do s\u1ef1 b\u1ea5t l\u1ef1c c\u1ee7a tr\u1ecdng l\u1ef1c trong vi\u1ec7c v\u01b0\u1ee3t qua c\u00e1c l\u1ef1c li\u00ean nguy\u00ean t\u1eed trong c\u00e1c kh\u1ed1i \u0111\u00e1 c\u1ee7a tr\u00e1i \u0111\u1ea5t. C\u00e1c v\u00ed d\u1ee5 r\u00f5 r\u00e0ng nh\u1ea5t ch\u00ednh l\u00e0 c\u00e1c d\u00e3y n\u00fai v\u00e0 c\u00e1c v\u1ef1c s\u00e2u \u1edf \u0111\u1ea1i d\u01b0\u01a1ng nh\u01b0ng s\u1ef1 nh\u1ea5p nh\u00f4 \u1edf quy m\u00f4 l\u1edbn h\u01a1n c\u0169ng \u0111\u00e3 \u0111\u01b0\u1ee3c ti\u1ebft l\u1ed9 nh\u1edd c\u00e1c nghi\u00ean c\u1ee9u t\u1eeb v\u1ec7 tinh, v\u1edbi qu\u1ef9 \u0111\u1ea1o v\u1ec7 tinh b\u1ecb t\u00e1c \u0111\u1ed9ng do s\u1ef1 thay \u0111\u1ed5i c\u1ee7a tr\u01b0\u1eddng tr\u1ecdng l\u1ef1c. Th\u00e1ng 12 n\u0103m 1958, c\u00e1c nh\u00e0 khoa h\u1ecdc M\u1ef9 \u0111\u00e3 th\u00f4ng b\u00e1o v\u1ec1 vi\u1ec7c kh\u00e1m ph\u00e1 \u0111\u1ed9 tr\u0169ng 15m \u1edf Nam c\u1ef1c, ng\u1ee5 \u00fd r\u1eb1ng tr\u00e1i \u0111\u1ea5t l\u00e0 m\u1ed9t qu\u1ea3 l\u00ea r\u1ea5t m\u1eadp. T\u1eeb \u0111\u00f3, c\u00e1c t\u00e0u th\u0103m d\u00f2 \u0111\u00e3 \u0111\u1ebfn th\u0103m t\u1ea5t c\u1ea3 c\u00e1c h\u00e0nh tinh l\u00e1ng gi\u1ec1ng c\u1ee7a ch\u00fang ta ngo\u1ea1i tr\u1eeb sao Di\u00eam V\u01b0\u01a1ng v\u00e0 ti\u1ebfn h\u00e0nh c\u00e1c nghi\u00ean 80 https:\/\/thuviensach.vn","c\u1ee9u chi ti\u1ebft v\u1ec1 h\u00ecnh d\u1ea1ng c\u1ee7a ch\u00fang. C\u00e1c nghi\u00ean c\u1ee9u n\u00e0y \u0111\u00e3 kh\u1eb3ng \u0111\u1ecbnh r\u1eb1ng sao Th\u1ed5 l\u00e0 h\u00e0nh tinh \u00edt tr\u00f2n nh\u1ea5t, t\u1ed1c \u0111\u1ed9 xoay nhanh c\u1ee7a n\u00f3 khi\u1ebfn cho n\u00f3 r\u1ed9ng h\u01a1n 11.000km t\u1ea1i \u0111\u01b0\u1eddng x\u00edch \u0111\u1ea1o so v\u1edbi t\u1ea1i c\u00e1c c\u1ef1c. 60 T\u1ea1i sao t\u1ea5t c\u1ea3 c\u00e1c h\u00e0nh tinh, c\u00e1c ng\u00f4i sao v\u00e0 c\u00e1c thi\u00ean h\u00e0 \u0111\u1ec1u xoay? Nguy\u00ean nh\u00e2n ch\u00ednh l\u00e0 do m\u1ed9t s\u1ef1 k\u1ebft h\u1ee3p gi\u1eefa tr\u1ecdng l\u1ef1c v\u00e0 s\u1ef1 b\u1ea3o t\u1ed3n moment g\u00f3c. Khi s\u1ef1 t\u00edch t\u1ee5 c\u1ee7a kh\u00ed v\u00e0 b\u1ee5i v\u0169 tr\u1ee5 gi\u1ea3m xu\u1ed1ng d\u01b0\u1edbi ho\u1ea1t \u0111\u1ed9ng c\u1ee7a tr\u1ecdng l\u1ef1c, ch\u1ec9 m\u1ed9t s\u1ef1 xo\u00e1y nh\u1ecf trong v\u1eadt ch\u1ea5t nguy\u00ean th\u1ee7y (c\u00f3 th\u1ec3 li\u00ean quan t\u1edbi s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng h\u1ed7n lo\u1ea1n c\u1ee7a kh\u00ed v\u00e0 b\u1ee5i) c\u0169ng s\u1ebd b\u1ecb khu\u1ebfch \u0111\u1ea1i th\u00e0nh s\u1ef1 xoay th\u1ef1c s\u1ef1 c\u1ee7a v\u1eadt th\u1ec3 cu\u1ed1i c\u00f9ng - gi\u1ed1ng nh\u01b0 m\u1ed9t v\u1eadn \u0111\u1ed9ng vi\u00ean tru\u1ee3t b\u0103ng k\u00e9o c\u00e1c c\u00e1nh tay c\u1ee7a m\u00ecnh. S\u1ef1 va ch\u1ea1m g\u1ea7n v\u1edbi l\u1ef1c tr\u1ecdng tr\u01b0\u1eddng v\u00e0 nh\u1eefng va ch\u1ea1m th\u1ef1c s\u1ef1 c\u0169ng c\u00f3 th\u1ec3 t\u1ea1o n\u00ean moment xoay, \u0111\u1eb7c bi\u1ec7t l\u00e0 \u1edf nh\u1eefng v\u1eadt th\u1ec3 c\u00f3 k\u00edch th\u01b0\u1edbc nh\u1ecf h\u01a1n c\u00e1c h\u00e0nh tinh. Tr\u00e1i \u0111\u1ea5t \u0111\u01b0\u1ee3c cho l\u00e0 \u0111\u00e3 nh\u1eadn \u0111\u01b0\u1ee3c moment xoay sau khi b\u1ecb va ch\u1ea1m v\u1edbi m\u1ed9t v\u1eadt th\u1ec3 c\u00f3 k\u00edch th\u01b0\u1edbc c\u1ee1 sao H\u1ecfa ngay sau khi n\u00f3 \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh. 81 https:\/\/thuviensach.vn","Tuy nhi\u00ean, trong khi c\u00e1c hi\u1ec7u \u1ee9ng n\u00e0y c\u00f3 th\u1ec3 gi\u1ea3i th\u00edch \u0111\u01b0\u1ee3c hi\u1ec7n t\u01b0\u1ee3ng c\u0103n b\u1ea3n th\u00ec vi\u1ec7c gi\u1ea3i th\u00edch chi ti\u1ebft ch\u00ednh x\u00e1c l\u1ea1i kh\u00f3 h\u01a1n nhi\u1ec1u. V\u00ed d\u1ee5, n\u1ebfu c\u1ea3 m\u1eb7t tr\u1eddi v\u00e0 c\u00e1c h\u00e0nh tinh \u0111\u1ec1u \u0111\u01b0\u1ee3c c\u00f4 \u0111\u1eb7c l\u1ea1i t\u1eeb m\u1ed9t kh\u1ed1i chung c\u00e1c v\u1eadt ch\u1ea5t \u0111ang xoay, hi\u1ec7u \u1ee9ng khu\u1ebfch \u0111\u1ea1i c\u00f3 th\u1ec3 khi\u1ebfn m\u1eb7t tr\u1eddi ph\u1ea3i xoay nhanh h\u01a1n nhi\u1ec1u so v\u1edbi hi\u1ec7n nay; chu k\u1ef3 xoay ung dung 25 ng\u00e0y c\u1ee7a n\u00f3 g\u1ee3i \u00fd r\u1eb1ng c\u00f3 m\u1ed9t \u201chi\u1ec7u \u1ee9ng phanh\u201d tinh vi n\u00e0o \u0111\u00f3. 61 T\u1ea1i sao \u0111\u00f4i khi b\u1ea1n c\u00f3 th\u1ec3 th\u1ea5y n\u1eeda t\u1ed1i c\u1ee7a m\u1ed9t m\u1eb7t tr\u0103ng l\u01b0\u1ee1i li\u1ec1m? Nguy\u00ean nh\u00e2n c\u1ee7a hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y ch\u00ednh l\u00e0 \u201c\u00e1nh m\u1eb7t \u0111\u1ea5t\u201d, \u0111\u01b0\u1ee3c t\u1ea1o ra do m\u1eb7t tr\u0103ng \u0111ang \u0111\u01b0\u1ee3c chi\u1ebfu s\u00e1ng b\u1edfi \u00e1nh s\u00e1ng m\u1eb7t tr\u1eddi d\u1ed9i l\u1ea1i t\u1eeb tr\u00e1i \u0111\u1ea5t. Hi\u1ec7u \u1ee9ng n\u00e0y \u0111\u01b0\u1ee3c gi\u1ea3i th\u00edch l\u1ea7n \u0111\u1ea7u b\u1edfi Leonardo da Vinci c\u00e1ch \u0111\u00e2y g\u1ea7n 500 n\u0103m v\u00e0 h\u00ecnh d\u1ea1ng c\u1ee7a n\u00f3 g\u1ea7n gi\u1ed1ng tr\u0103ng non, khi tr\u00e1i \u0111\u1ea5t \u0111\u01b0\u1ee3c chi\u1ebfu s\u00e1ng \u0111\u1ea7y \u0111\u1ee7 b\u1edfi m\u1eb7t tr\u1eddi v\u00e0 do \u0111\u00f3 ph\u1ea3n chi\u1ebfu h\u1ea7u h\u1ebft \u00e1nh s\u00e1ng m\u1eb7t tr\u1eddi l\u00ean m\u1eb7t tr\u0103ng - thi\u00ean th\u1ec3 \u0111\u1ed3ng h\u00e0nh c\u1ee7a n\u00f3. \u00c1nh m\u1eb7t \u0111\u1ea5t m\u1ea1nh h\u01a1n khi trong kh\u00ed quy\u1ec3n c\u1ee7a ch\u00fang ta c\u00f3 nhi\u1ec1u \u0111\u00e1m m\u00e2y ph\u1ea3n chi\u1ebfu \u00e1nh s\u00e1ng h\u01a1n - do \u0111\u00f3 \u0111\u00e3 d\u1eabn d\u1eaft m\u1ed9t 82 https:\/\/thuviensach.vn","s\u1ed1 nh\u00e0 khoa h\u1ecdc t\u1edbi vi\u1ec7c s\u1eed d\u1ee5ng \u00e1nh m\u1eb7t \u0111\u1ea5t \u0111\u1ec3 theo d\u00f5i s\u1ef1 thay \u0111\u1ed5i kh\u00ed h\u1eadu tr\u00e1i \u0111\u1ea5t. 62 T\u1ea1i sao m\u1eb7t tr\u0103ng lu\u00f4n h\u01b0\u1edbng c\u00f9ng m\u1ed9t m\u1eb7t v\u1ec1 ph\u00eda tr\u00e1i \u0111\u1ea5t? B\u1ea5t ch\u1ea5p b\u1ec1 ngo\u00e0i, m\u1eb7t tr\u0103ng xoay quanh tr\u1ee5c c\u1ee7a n\u00f3 m\u1ed9t v\u00f2ng m\u1ed7i 27,3 ng\u00e0y. L\u00fd do ch\u00fang ta kh\u00f4ng nh\u1eadn ra l\u00e0 v\u00ec n\u00f3 tr\u00f9ng h\u1ee3p v\u1edbi v\u1eadn t\u1ed1c m\u00e0 m\u1eb7t tr\u0103ng xoay quanh tr\u00e1i \u0111\u1ea5t, do \u0111\u00f3 \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00f9ng m\u1ed9t m\u1eb7t s\u1ebd lu\u00f4n lu\u00f4n \u0111\u01b0\u1ee3c h\u01b0\u1edbng v\u1ec1 ph\u00eda ch\u00fang ta (m\u1eb7c d\u00f9 c\u00f3 m\u1ed9t v\u00e0i hi\u1ec7u \u1ee9ng kh\u00f3 th\u1ea5y th\u1ef1c s\u1ef1 cho ph\u00e9p ch\u00fang ta h\u00e9 nh\u00ecn qua m\u1ed7i b\u00ean v\u00e0 th\u1ea5y \u0111\u01b0\u1ee3c t\u1edbi 59% b\u1ec1 m\u1eb7t). S\u1ef1 xoay \u0111\u1ed3ng b\u1ed9 n\u00e0y \u0111\u01b0\u1ee3c g\u00e2y ra ch\u1ee7 y\u1ebfu l\u00e0 do tr\u1ecdng l\u1ef1c c\u1ee7a tr\u00e1i \u0111\u1ea5t \u0111\u00e3 l\u00e0m sai l\u1ec7ch d\u1ea1ng quay c\u1ee7a m\u1eb7t tr\u0103ng khi n\u00f3 bay quanh ch\u00fang ta, t\u00e1c \u0111\u1ed9ng m\u1ed9t l\u1ef1c phanh khi\u1ebfn cho m\u1eb7t tr\u0103ng b\u1ecb th\u00fac \u00e9p ph\u1ea3i \u0111\u1ed3ng b\u1ed9 t\u1ed1c \u0111\u1ed9 t\u1ef1 xoay v\u1edbi chu k\u1ef3 qu\u1ef9 \u0111\u1ea1o c\u1ee7a n\u00f3. H\u1ea7u nh\u01b0 t\u1ea5t c\u1ea3 m\u1eb7t tr\u0103ng trong h\u1ec7 m\u1eb7t tr\u1eddi \u0111\u1ec1u bi\u1ec3n hi\u1ec7n s\u1ef1 xoay \u0111\u1ed3ng b\u1ed9 nh\u01b0ng ch\u1ec9 c\u00f3 m\u1ed9t h\u00e0nh tinh c\u00f3 c\u00e1c d\u1ea5u hi\u1ec7u chuy\u1ec3n \u0111\u1ed9ng t\u01b0\u01a1ng t\u1ef1: sao Th\u1ee7y, do s\u1ef1 k\u1ec1 c\u1eadn t\u01b0\u01a1ng \u0111\u1ed1i v\u1edbi m\u1eb7t tr\u1eddi \u0111\u00e3 l\u00e0m ch\u1eadm t\u1ed1c \u0111\u1ed9 t\u1ef1 xoay c\u1ee7a n\u00f3 t\u1edbi m\u1ed9t v\u00f2ng m\u1ed7i 58 ng\u00e0y. Tr\u00e1i \u0111\u1ea5t th\u00ec qu\u00e1 xa m\u1eb7t tr\u1eddi khi\u1ebfn cho l\u1ef1c phanh n\u00e0y c\u1ef1c k\u1ef3 y\u1ebfu v\u00e0 do \u0111\u00f3 kh\u00f4ng c\u00f3 nguy c\u01a1 (hay hy v\u1ecdng, t\u00f9y quan \u0111i\u1ec3m m\u1ed7i ng\u01b0\u1eddi) n\u00e0o \u0111\u1ec3 cho t\u1ed1c \u0111\u1ed9 t\u1ef1 xoay c\u1ee7a n\u00f3 cu\u1ed1i c\u00f9ng l\u1ea1i \u0111\u1ea1t t\u1edbi \u0111i\u1ec3m m\u00e0 m\u1ed9t m\u1eb7t c\u1ee7a h\u00e0nh tinh ch\u00fang ta \u0111\u1ed1i di\u1ec7n th\u01b0\u1eddng xuy\u00ean v\u1edbi m\u1eb7t tr\u1eddi. 83 https:\/\/thuviensach.vn","63 Kh\u1ea3 n\u0103ng s\u1ef1 s\u1ed1ng t\u01b0\u01a1ng t\u1ef1 nh\u01b0 \u1edf tr\u00e1i \u0111\u1ea5t t\u1ed3n t\u1ea1i \u1edf c\u00e1c n\u01a1i kh\u00e1c trong v\u0169 tr\u1ee5 l\u00e0 bao nhi\u00eau? N\u1ebfu c\u1ee9 h\u00ecnh dung theo b\u1ed9 phim khoa h\u1ecdc vi\u1ec5n t\u01b0\u1edfng Star Trek, v\u0169 tr\u1ee5 c\u00f3 \u0111\u1ea7y c\u00e1c d\u1ea1ng s\u1ed1ng tr\u00f4ng r\u1ea5t gi\u1ed1ng con ng\u01b0\u1eddi, ngo\u1ea1i tr\u1eeb vi\u1ec7c h\u1ecd c\u00f3 c\u00e1c l\u1ed7 tai nh\u1ecdn hay ng\u00f3n tay tr\u1ecf to\u1ea3 s\u00e1ng. N\u1ebfu v\u0169 tr\u1ee5 c\u1ee7a ch\u00fang ta th\u1eadt s\u1ef1 l\u00e0 v\u00f4 h\u1ea1n (v\u00e0 nh\u01b0 tri\u1ebft gia La M\u00e3 Lucretius \u0111\u00e3 ch\u1ec9 ra, n\u00f3 c\u00f2n c\u00f3 th\u1ec3 l\u00e0 g\u00ec ch\u1ee9?), v\u1eady th\u00ec ho\u00e0n to\u00e0n ch\u1eafc ch\u1eafn l\u00e0 s\u1ebd c\u00f3 c\u00e1c d\u1ea1ng s\u1ed1ng gi\u1ed1ng nh\u01b0 ch\u00fang ta t\u1edbi t\u1eebng chi ti\u1ebft t\u1ed3n t\u1ea1i \u0111\u00e2u \u0111\u00f3 ngo\u00e0i v\u0169 tr\u1ee5 kia - tuy nhi\u00ean, c\u0169ng c\u00f3 m\u1ed9t \u0111i\u1ec1u ch\u1eafc ch\u1eafn r\u1eb1ng, ch\u00fang ta c\u00f3 v\u1ebb nh\u01b0 s\u1ebd kh\u00f4ng bao gi\u1edd c\u00f3 th\u1ec3 g\u1eb7p \u0111\u01b0\u1ee3c h\u1ecd. Ch\u1ec9 c\u1ea7n m\u1ed9t ki\u1ebfn th\u1ee9c s\u01a1 l\u01b0\u1ee3c v\u1ec1 qu\u00e1 tr\u00ecnh ti\u1ebfn h\u00f3a c\u1ee7a s\u1ef1 s\u1ed1ng tr\u00ean h\u00e0nh tinh n\u00e0y c\u0169ng \u0111\u1ee7 \u0111\u1ec3 th\u1ea5y r\u00f5 r\u1eb1ng ch\u1ec9 c\u00f3 m\u1ed9t kh\u1ea3 n\u0103ng v\u00f4 c\u00f9ng nh\u1ecf \u0111\u1ec3 m\u1ed9t chu\u1ed7i c\u00e1c s\u1ef1 ki\u1ec7n gi\u1ed1ng nh\u01b0 v\u1eady s\u1ebd \u0111\u01b0\u1ee3c l\u1eb7p l\u1ea1i \u1edf n\u01a1i kh\u00e1c, \u00edt nh\u1ea5t l\u00e0 \u1edf trong v\u00f9ng v\u0169 tr\u1ee5 \u0111\u00e3 bi\u1ebft c\u1ee7a ch\u00fang ta. \u0110\u1ea7u ti\u00ean c\u1ea7n ph\u1ea3i c\u00f3 s\u1ef1 h\u00ecnh th\u00e0nh c\u1ee7a m\u1ed9t h\u00e0nh tinh gi\u1ed1ng nh\u01b0 c\u1ee7a ch\u00fang ta, v\u1edbi \u0111\u00fang m\u1ed9t kho\u1ea3ng c\u00e1ch nh\u01b0 v\u1eady t\u1edbi m\u1ed9t ng\u00f4i sao c\u0169ng gi\u1ed1ng nh\u01b0 m\u1eb7t tr\u1eddi v\u00e0 c\u00f3 m\u1ed9t h\u1ed7n h\u1ee3p c\u00e1c ch\u1ea5t kh\u00ed trong kh\u00ed quy\u1ec3n th\u1eadt ph\u00f9 h\u1ee3p. Sau \u0111\u00f3 c\u00e1c qu\u00e1 tr\u00ecnh sinh h\u00f3a d\u1eabn t\u1edbi s\u1ef1 xu\u1ea5t hi\u1ec7n c\u1ee7a m\u1ed9t d\u1ea1ng s\u1ed1ng d\u1ef1a tr\u00ean DNA ph\u1ea3i \u0111\u01b0\u1ee3c l\u1eb7p l\u1ea1i. Do ch\u00fang ta v\u1eabn ch\u01b0a bi\u1ebft ch\u00ednh x\u00e1c c\u00e1c qu\u00e1 tr\u00ecnh tr\u00ean di\u1ec5n ra nh\u01b0 th\u1ebf n\u00e0o, n\u00ean th\u1eadt kh\u00f3 \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 nh\u01b0ng ng\u01b0\u1eddi ta \u0111\u00e3 \u01b0\u1edbc l\u01b0\u1ee3ng r\u1eb1ng m\u1ed9t t\u1ebf b\u00e0o s\u1ed1ng \u0111\u01a1n gi\u1ea3n nh\u1ea5t c\u1ea7n \u00edt nh\u1ea5t 50 gen v\u00e0 84 https:\/\/thuviensach.vn","c\u01a1 may \u0111\u1ec3 m\u1ed9t chu\u1ed7i DNA ch\u00ednh x\u00e1c nh\u01b0 v\u1eady \u0111\u01b0\u1ee3c l\u1eb7p l\u1ea1i m\u1ed9t l\u1ea7n n\u1eefa l\u00e0 1\/10 ti\u1ebfp t\u1ee5c v\u1edbi 5400 con s\u1ed1 0. C\u00e1c \u0111i\u1ec1u ng\u1eabu nhi\u00ean kh\u00f4ng th\u1ec3 xu\u1ea5t hi\u1ec7n li\u00ean t\u1ee5c l\u00e2u nh\u01b0 th\u1ebf. \u00dd t\u01b0\u1edfng v\u1ec1 tr\u1ecdng l\u1ef1c 64 nh\u00e2n t\u1ea1o trong c\u00e1c t\u00e0u kh\u00f4ng gian \u0111\u00e3 \u0111i v\u1ec1 \u0111\u00e2u? Ai \u0111\u00e3 t\u1eebng bi\u1ebft qua c\u00e2u chuy\u1ec7n Dan Dare v\u00e0 2001: M\u1ed9t cu\u1ed9c phi\u00eau l\u01b0u kh\u00f4ng gian, ch\u1eafc s\u1ebd t\u01b0\u1edfng t\u01b0\u1ee3ng l\u00e0 c\u00e1c tr\u1ea1m kh\u00f4ng gian bay b\u00ean tr\u00ean ch\u00fang ta s\u1ebd th\u1ef1c hi\u1ec7n m\u1ed9t s\u1ef1 xoay tr\u00f2n \u1ed5n \u0111\u1ecbnh \u0111\u1ec3 t\u1ea1o cho nh\u1eefng ng\u01b0\u1eddi s\u1ed1ng trong \u0111\u00f3 c\u1ea3m gi\u00e1c v\u1ec1 tr\u1ecdng l\u1ef1c nh\u1edd hi\u1ec7u \u1ee9ng ly t\u00e2m gi\u1ed1ng nh\u01b0 \u201cm\u00e1y s\u1ea5y qu\u1ea7n \u00e1o\u201d. Tuy nhi\u00ean, gi\u1edd \u0111\u00e3 qua n\u0103m 2001 t\u1eeb l\u00e2u v\u00e0 c\u00e1c phi h\u00e0nh gia tr\u00ean Tr\u1ea1m kh\u00f4ng gian qu\u1ed1c t\u1ebf v\u1eabn c\u00f2n tr\u00f4i v\u00f4 \u0111\u1ecbnh xung quanh gi\u1ed1ng nh\u01b0 nh\u1eefng qu\u1ea3 bong b\u00f3ng. M\u1eb7c d\u00f9 r\u1ea5t \u0111\u01a1n gi\u1ea3n t\u1eeb kh\u00eda c\u1ea1nh k\u1ef9 thu\u1eadt, ph\u01b0\u01a1ng ph\u00e1p \u201cm\u00e1y s\u1ea5y\u201d v\u1eabn t\u00e0n ph\u00e1 sinh l\u00fd c\u01a1 th\u1ec3 ng\u01b0\u1eddi. C\u00e1c th\u00ed nghi\u1ec7m ti\u1ebfn h\u00e0nh trong su\u1ed1t nh\u1eefng n\u0103m 1960 v\u00e0 1970 ph\u00e1t hi\u1ec7n r\u1eb1ng con ng\u01b0\u1eddi b\u1eaft \u0111\u1ea7u c\u1ea3m th\u1ea5y bu\u1ed3n n\u00f4n khi b\u1ecb xoay \u1edf v\u1eadn t\u1ed1c l\u1edbn h\u01a1n hai v\u00f2ng m\u1ed7i ph\u00fat. Nh\u01b0 v\u1eady l\u00e0 qu\u00e1 ch\u1eadm \u0111\u1ec3 m\u1ed9t tr\u1ea1m kh\u00f4ng gian r\u1ed9ng h\u01a1n 85 https:\/\/thuviensach.vn","300km c\u00f3 th\u1ec3 m\u00f4 ph\u1ecfng m\u1ed9t l\u1ef1c ly t\u00e2m gi\u1ed1ng nh\u01b0 tr\u1ecdng l\u1ef1c c\u1ee7a tr\u00e1i \u0111\u1ea5t - l\u1ef1c l\u1edbn h\u01a1n nhi\u1ec1u so v\u1edbi nh\u1eefng g\u00ec c\u00f3 th\u1ec3 l\u00e0m trong hi\u1ec7n t\u1ea1i. N\u1ebfu con ng\u01b0\u1eddi mu\u1ed1n th\u00e1m hi\u1ec3m kh\u00f4ng gian xa h\u01a1n n\u1eefa, v\u1ea5n \u0111\u1ec1 tr\u1ecdng l\u1ef1c nh\u00e2n t\u1ea1o nh\u1ea5t \u0111\u1ecbnh ph\u1ea3i \u0111\u01b0\u1ee3c gi\u1ea3i quy\u1ebft, v\u00ec nh\u1eefng nghi\u00ean c\u1ee9u tr\u00ean c\u00e1c phi h\u00e0nh gia trong c\u00e1c s\u1ee9 m\u1ec7nh kh\u00f4ng gian l\u00e2u d\u00e0i \u0111\u00e3 ch\u1ec9 ra r\u1eb1ng \u1edf trong t\u00ecnh tr\u1ea1ng kh\u00f4ng tr\u1ecdng l\u1ef1c k\u00e9o d\u00e0i s\u1ebd l\u00e0m y\u1ebfu c\u01a1 v\u00e0 x\u01b0\u01a1ng. M\u1ed9t \u00fd t\u01b0\u1edfng kh\u00e1c l\u00e0 cho c\u00e1c phi h\u00e0nh gia \u0111\u01b0\u1ee3c \u1edf trong m\u00f4i tr\u01b0\u1eddng tr\u1ecdng l\u1ef1c t\u1eebng l\u00fac m\u1ed9t, trong m\u1ed9t \u201cm\u00e1y s\u1ea5y\u201d \u1edf tr\u00ean t\u00e0u v\u1edbi k\u00edch th\u01b0\u1edbc v\u1eeba m\u1ed9t ng\u01b0\u1eddi. Nh\u1eefng k\u00edch th\u01b0\u1edbc nh\u1ecf c\u1ee7a m\u00e1y n\u00e0y c\u00f3 ngh\u0129a l\u00e0 v\u1eadn t\u1ed1c xoay ph\u1ea3i \u0111\u1ea1t t\u1edbi 20 v\u00f2ng m\u1ed7i ph\u00fat v\u00e0 c\u00e1c th\u00ed nghi\u1ec7m \u0111\u00e3 ch\u1ee9ng t\u1ecf r\u1eb1ng n\u00f4n \u00f3i th\u1ef1c s\u1ef1 l\u00e0 m\u1ed9t v\u1ea5n \u0111\u1ec1. C\u0169ng c\u00f3 \u0111\u1ec1 xu\u1ea5t t\u1ea1o ra tr\u1ecdng l\u1ef1c nh\u00e2n t\u1ea1o b\u1eb1ng c\u00e1ch \u0111\u1ea9y c\u1ea3 phi thuy\u1ec1n t\u1edbi tr\u01b0\u1edbc v\u1edbi gia t\u1ed1c gi\u1ed1ng nh\u01b0 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng c\u1ee7a tr\u00e1i \u0111\u1ea5t. Th\u1eadt kh\u00f4ng may, ch\u01b0a ai c\u00f3 th\u1ec3 ph\u00e1t minh m\u1ed9t h\u1ec7 th\u1ed1ng \u0111\u1ea9y c\u00f3 kh\u1ea3 n\u0103ng phi th\u01b0\u1eddng nh\u01b0 v\u1eady. 65 B\u1eb1ng c\u00e1ch n\u00e0o t\u00ecnh tr\u1ea1ng kh\u00f4ng tr\u1ecdng l\u1ef1c \u0111\u01b0\u1ee3c t\u1ea1o ra trong m\u1ed9t m\u00e1y bay? C\u00e1i m\u1eb9o l\u00e0 h\u00e3y \u0111\u1eb7t m\u00e1y bay v\u00e0o m\u1ed9t \u0111\u01b0\u1eddng bay ch\u00fac xu\u1ed1ng gi\u1ed1ng nh\u01b0 \u0111\u01b0\u1eddng bay c\u1ee7a m\u1ed9t v\u1eadt th\u1ec3 b\u1ecb n\u00e9m kh\u1ecfi v\u00e1ch \u0111\u00e1 v\u1edbi c\u00f9ng m\u1ed9t v\u1eadn t\u1ed1c ngang gi\u1ed1ng nh\u01b0 m\u00e1y bay. H\u00ecnh d\u1ea1ng c\u1ee7a \u0111\u01b0\u1eddng bay n\u00e0y l\u00e0 m\u1ed9t ph\u1ea7n 86 https:\/\/thuviensach.vn","parabol v\u00e0 trong khi \u0111i theo d\u1ea1ng \u0111\u00f3, m\u00e1y bay v\u00e0 c\u00e1c v\u1eadt b\u00ean trong s\u1ebd ho\u1ea1t \u0111\u1ed9ng nh\u01b0 \u0111ang r\u01a1i t\u1ef1 do, t\u1ea5t c\u1ea3 m\u1ecdi th\u1ee9 r\u01a1i th\u1eb3ng v\u1ec1 m\u1eb7t \u0111\u1ea5t v\u1edbi c\u00f9ng m\u1ed9t gia t\u1ed1c. Do \u0111\u00f3, v\u00ec phi h\u00e0nh \u0111o\u00e0n v\u00e0 h\u00e0nh kh\u00e1ch trong m\u00e1y bay \u0111\u1ec1u \u0111ang r\u01a1i nhanh nh\u01b0 s\u00e0n c\u1ee7a m\u00e1y bay, h\u1ecd c\u1ea3m th\u1ea5y nh\u01b0 \u0111ang l\u01a1 l\u1eedng trong kh\u00f4ng trung b\u00ean trong m\u00e1y bay. C\u1ea3m gi\u00e1c n\u00e0y kh\u00f4ng gi\u1ed1ng nhau \u0111\u1ed1i v\u1edbi t\u1ea5t c\u1ea3 m\u1ecdi ng\u01b0\u1eddi, v\u00ec NASA \u0111\u00e3 ph\u00e1t hi\u1ec7n r\u1eb1ng khi h\u1ecd s\u1eed d\u1ee5ng nh\u1eefng chuy\u1ebfn bay d\u1ea1ng parabol n\u00e0y \u0111\u1ec3 cho c\u00e1c phi h\u00e0nh gia t\u01b0\u01a1ng lai c\u1ea3m gi\u00e1c kh\u00f4ng tr\u1ecdng l\u1ef1c trong kho\u1ea3ng 30 gi\u00e2y, g\u1ea7n 1\/3 nh\u1eefng ng\u01b0\u1eddi n\u00e0y \u0111\u00e3 tr\u1edf n\u00ean bu\u1ed3n n\u00f4n nghi\u00eam tr\u1ecdng. Chi\u1ebfc m\u00e1y bay \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 th\u1ef1c hi\u1ec7n c\u00e1c chuy\u1ebfn bay \u0111\u00f3 sau n\u00e0y \u0111\u01b0\u1ee3c g\u1ecdi v\u1edbi c\u00e1i t\u00ean \u201cSao ch\u1ed5i n\u00f4n\u201d! 66 T\u1ea1i sao nh\u1eefng ng\u01b0\u1eddi \u1edf ph\u00eda nam c\u1ee7a \u0111\u01b0\u1eddng x\u00edch \u0111\u1ea1o kh\u00f4ng c\u1ea3m th\u1ea5y h\u1ecd b\u1ecb l\u1ed9n ng\u01b0\u1ee3c? C\u1ea3m gi\u00e1c c\u1ee7a ch\u00fang ta v\u1ec1 vi\u1ec7c l\u00ean v\u00e0 xu\u1ed1ng c\u00f3 \u0111\u01b0\u1ee3c l\u00e0 do s\u1ecfi th\u00ednh gi\u00e1c \u1edf tai trong. M\u1ed7i c\u01a1 quan n\u00e0y c\u00f3 m\u1ed9t v\u00f9ng c\u1ea3m gi\u00e1c nh\u1ecf, r\u1ed9ng kho\u1ea3ng 2mm, ch\u1ee9a nhi\u1ec1u ng\u00e0n t\u1ebf b\u00e0o l\u00f4ng. Nh\u1eefng s\u1ee3i l\u00f4ng nh\u1ecf nh\u00f4 ra t\u1eeb c\u00e1c t\u1ebf b\u00e0o n\u00e0y d\u00f2 t\u00ecm c\u00e1c chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a c\u00e1c h\u1ea1t s\u1ecfi th\u00ednh gi\u00e1c gi\u1ed1ng nh\u01b0 ph\u1ea5n. V\u00ec chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a c\u00e1c h\u1ea1t n\u00e0y b\u1ecb t\u00e1c \u0111\u1ed9ng b\u1edfi tr\u1ecdng l\u1ef1c n\u00ean t\u1ea1o 87 https:\/\/thuviensach.vn","cho ch\u00fang ta c\u1ea3m gi\u00e1c \u0111\u1ee9ng th\u1eb3ng hay l\u1ed9n ng\u01b0\u1ee3c m\u1ed9t c\u00e1ch t\u01b0\u01a1ng \u0111\u1ed1i so v\u1edbi tr\u1ecdng l\u1ef1c. 67 B\u1eb1ng c\u00e1ch n\u00e0o v\u00e0 khi n\u00e0o m\u00e0 tr\u00e1i \u0111\u1ea5t c\u00f3 \u0111\u01b0\u1ee3c m\u1eb7t tr\u0103ng? Ch\u01b0\u01a1ng tr\u00ecnh Apollo th\u01b0\u1eddng b\u1ecb ch\u1ec9 tr\u00edch v\u00ec \u0111\u00e3 quan t\u00e2m chuy\u1ec7n \u0111\u00e1nh b\u1ea1i ng\u01b0\u1eddi Nga h\u01a1n l\u00e0 \u0111\u00f3ng g\u00f3p cho hi\u1ec3u bi\u1ebft c\u1ee7a con ng\u01b0\u1eddi ngo\u1ea1i tr\u1eeb m\u1ed9t kh\u1ed1i \u0111\u00e1 m\u1eb7t tr\u0103ng n\u1eb7ng 387kg m\u00e0 h\u1ecd \u0111\u00e3 k\u00e9o v\u1ec1 v\u00e0 gi\u00fap soi r\u1ecdi \u00e1nh s\u00e1ng ch\u1ee7 y\u1ebfu v\u1ec1 ngu\u1ed3n g\u1ed1c c\u1ee7a thi\u00ean th\u1ec3 l\u00e1ng gi\u1ec1ng g\u1ea7n nh\u1ea5t c\u1ee7a ch\u00fang ta. Tr\u01b0\u1edbc khi Neil Armstrong b\u01b0\u1edbc l\u00ean m\u1eb7t tr\u0103ng, c\u00f3 r\u1ea5t nhi\u1ec1u h\u1ecdc thuy\u1ebft c\u1ea1nh tranh v\u1edbi nhau, t\u1eeb vi\u1ec7c tr\u00e1i \u0111\u1ea5t ch\u1ec9 \u0111\u01a1n gi\u1ea3n gi\u1eef l\u1ea5y m\u1eb7t tr\u0103ng khi n\u00f3 \u0111i lang thang qua cho t\u1edbi vi\u1ec7c m\u1eb7t tr\u0103ng b\u1ecb phun ra nh\u01b0 m\u1ed9t gi\u1ecdt n\u01b0\u1edbc kh\u1ed5ng l\u1ed3 khi tr\u00e1i \u0111\u1ea5t v\u1eabn c\u00f2n n\u00f3ng ch\u1ea3y. Nh\u1eefng ph\u00e2n t\u00edch h\u00f3a h\u1ecdc c\u1ee7a c\u00e1c m\u1eabu \u0111\u00e1 m\u1eb7t tr\u0103ng \u0111\u00e3 gi\u00f3ng l\u00ean h\u1ed3i chu\u00f4ng b\u00e1o t\u1eed cho h\u1ea7u h\u1ebft c\u00e1c h\u1ecdc thuy\u1ebft, b\u1edfi v\u00ec ch\u00fang \u0111\u00e3 ti\u1ebft l\u1ed9 nh\u1eefng t\u01b0\u01a1ng \u0111\u1ed3ng s\u00e2u s\u1eafc v\u1edbi th\u00e0nh ph\u1ea7n c\u1ee7a v\u1ecf tr\u00e1i \u0111\u1ea5t. T\u1edbi gi\u1eefa nh\u1eefng n\u0103m 1970, m\u1ed9t h\u1ecdc thuy\u1ebft m\u1edbi l\u1ea1i b\u1eaft \u0111\u1ea7u n\u1ed5i l\u00ean, trong \u0111\u00f3 m\u1eb7t tr\u0103ng l\u00e0 s\u1ea3n ph\u1ea9m c\u1ee7a m\u1ed9t c\u00fa va ch\u1ea1m kh\u1ee7ng khi\u1ebfp gi\u1eefa tr\u00e1i \u0111\u1ea5t v\u1edbi m\u1ed9t v\u00e0i thi\u00ean th\u1ec3 kh\u00e1c c\u00f3 k\u00edch th\u01b0\u1edbc c\u1ee1 h\u00e0nh tinh, ngay sau s\u1ef1 h\u00ecnh l\u1eadp c\u1ee7a h\u1ec7 m\u1eb7t tr\u1eddi. C\u00fa va ch\u1ea1m kh\u1ee7ng khi\u1ebfp t\u1edbi m\u1ee9c \u0111\u00e3 kho\u00e9t m\u1ed9t m\u1ea3nh v\u1ee1 l\u1edbn t\u1eeb c\u00e1c v\u1eadt ch\u1ea5t b\u00ean trong tr\u00e1i \u0111\u1ea5t v\u00e0 m\u1ea3nh v\u1ee1 n\u00e0y sau 88 https:\/\/thuviensach.vn","\u0111\u00f3 \u0111\u00e3 t\u1ee5 h\u1ecdp l\u1ea1i d\u01b0\u1edbi tr\u1ecdng l\u1ef1c c\u1ee7a ch\u00ednh n\u00f3 th\u00e0nh m\u1ed9t qu\u1ea3 c\u1ea7u g\u1ecdn g\u00e0ng m\u00e0 ch\u00fang ta g\u1ecdi l\u00e0 m\u1eb7t tr\u0103ng. T\u00ednh to\u00e1n chi ti\u1ebft h\u01a1n, ch\u1eb3ng h\u1ea1n nh\u01b0 v\u1ec1 k\u00edch th\u01b0\u1edbc c\u1ee7a v\u1eadt th\u1ec3 \u0111\u00e3 va v\u00e0o tr\u00e1i \u0111\u1ea5t, ph\u1ea3i \u0111\u1ee3i t\u1edbi s\u1ef1 xu\u1ea5t hi\u1ec7n c\u1ee7a c\u00e1c si\u00eau m\u00e1y t\u00ednh \u0111\u1ee7 m\u1ea1nh \u0111\u1ec3 m\u00f4 ph\u1ecfng l\u1ea1i c\u00e1c hi\u1ec7u \u1ee9ng ph\u1ee9c t\u1ea1p c\u1ee7a c\u00fa va ch\u1ea1m v\u00e0 h\u1eadu qu\u1ea3 c\u1ee7a n\u00f3. Trong nh\u1eefng n\u0103m v\u1eeba qua, nh\u1eefng m\u00f4 ph\u1ecfng nh\u01b0 v\u1eady \u0111\u00e3 d\u1eabn \u0111\u1ebfn quan \u0111i\u1ec3m r\u1eb1ng tr\u00e1i \u0111\u1ea5t \u0111\u00e3 b\u1ecb va b\u1edfi m\u1ed9t thi\u00ean th\u1ec3 c\u00f3 k\u00edch th\u01b0\u1edbc c\u1ee1 sao H\u1ecfa v\u00e0 m\u1ea3nh v\u1ee1 - v\u1edbi kho\u1ea3ng 30% c\u1ee7a n\u00f3 l\u00e0 t\u1eeb tr\u00e1i \u0111\u1ea5t - \u0111\u00e3 t\u1ea1o n\u00ean m\u1eb7t tr\u0103ng v\u00e0o m\u1ed9t l\u00fac n\u00e0o \u0111\u00f3 trong 100 tri\u1ec7u n\u0103m \u0111\u1ea7u ti\u00ean c\u1ee7a l\u1ecbch s\u1eed tr\u00e1i \u0111\u1ea5t. Nh\u1eefng nghi\u00ean c\u1ee9u v\u1ec1 c\u00e1c thi\u00ean th\u1ea1ch ch\u1ec9 ra r\u1eb1ng c\u00e1c h\u00e0nh tinh \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh c\u00e1ch \u0111\u00e2y kho\u1ea3ng 4.540 tri\u1ec7u n\u0103m. Trong khi \u0111\u00f3 c\u00e1c ph\u00e2n t\u00edch c\u1ee7a \u0111\u00e1 m\u1eb7t tr\u0103ng l\u1ea1i g\u1ee3i \u00fd r\u1eb1ng m\u1eb7t tr\u0103ng \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh c\u00e1ch \u0111\u00e2u t\u1eeb 4.500 t\u1edbi 4.520 tri\u1ec7u n\u0103m. G\u1ed9p chung l\u1ea1i, ch\u00fang g\u1ee3i \u00fd r\u1eb1ng m\u1eb7t tr\u0103ng \u0111\u00e3 chuy\u1ec3n \u0111\u1ed9ng xung quanh tr\u00e1i \u0111\u1ea5t t\u1eeb sau khi tr\u00e1i \u0111\u1ea5t xu\u1ea5t hi\u1ec7n kho\u1ea3ng 20-40 tri\u1ec7u n\u0103m. 68 T\u1ea1i sao m\u1ed7i ng\u00e0y c\u00f3 hai \u0111\u1ee3t th\u1ee7y tri\u1ec1u l\u00ean? M\u1ed7i ng\u00e0y c\u0169ng c\u00f3 hai \u0111\u1ee3t th\u1ee7y tri\u1ec1u xu\u1ed1ng (n\u00f3i cho ch\u00ednh x\u00e1c th\u00ec l\u00e0 24 gi\u1edd 50 ph\u00fat, k\u1ebft qu\u1ea3 c\u1ee7a vi\u1ec7c m\u1eb7t tr\u0103ng \u0111\u00e3 di chuy\u1ec3n m\u1ed9t ch\u00fat tr\u00ean qu\u1ef9 \u0111\u1ea1o c\u1ee7a n\u00f3). M\u1ed9t suy ngh\u0129 d\u01b0\u1eddng nh\u01b0 h\u1ee3p l\u00fd r\u1eb1ng m\u1ed7i ng\u00e0y ch\u1ec9 c\u00f3 m\u1ed9t 89 https:\/\/thuviensach.vn","\u0111\u1ee3t th\u1ee7y tri\u1ec1u, khi ph\u1ea7n tr\u00e1i \u0111\u1ea5t c\u1ee7a ch\u00fang ta xoay tr\u00f2n \u0111\u1ec3 \u0111\u1ed1i di\u1ec7n v\u1edbi m\u1eb7t tr\u0103ng v\u00e0 do \u0111\u00f3 ch\u1ecbu t\u00e1c \u0111\u1ed9ng ho\u00e0n to\u00e0n b\u1edfi l\u1ef1c h\u1ea5p d\u1eabn c\u1ee7a n\u00f3. \u0110i\u1ec1u n\u00e0y \u0111\u00e3 b\u1ecf qua m\u1ed9t s\u1ef1 th\u1eadt l\u00e0 l\u1ef1c h\u1ea5p d\u1eabn kh\u00f4ng ch\u1ec9 \u0111\u01a1n gi\u1ea3n t\u00f3m l\u1ea5y b\u1ea5t c\u1ee9 th\u1ee9 g\u00ec g\u1ea7n nh\u1ea5t: n\u00f3 t\u00e1c \u0111\u1ed9ng t\u1edbi m\u1ecdi th\u1ee9, bao g\u1ed3m c\u1ea3 c\u00e1c \u0111\u1ea1i d\u01b0\u01a1ng \u1edf m\u1eb7t b\u00ean kia c\u1ee7a tr\u00e1i \u0111\u1ea5t, cho d\u00f9 ch\u1ec9 \u1edf m\u1ed9t m\u1ee9c \u0111\u1ed9 r\u1ea5t nh\u1ecf. N\u00f3 c\u0169ng \u0111\u00e3 b\u1ecf qua m\u1ed9t hi\u1ec7u \u1ee9ng tinh vi do s\u1ef1 k\u1ec1 c\u1eadn c\u1ee7a m\u1eb7t tr\u0103ng, hi\u1ec7u \u1ee9ng l\u00e0m cho tr\u00e1i \u0111\u1ea5t v\u00e0 m\u1eb7t tr\u0103ng xoay quanh nhau, t\u1ea1o ra m\u1ed9t l\u1ef1c ly t\u00e2m \u1edf m\u1eb7t b\u00ean kia c\u1ee7a tr\u00e1i \u0111\u1ea5t. Ch\u00ednh s\u1ef1 k\u1ebft h\u1ee3p c\u1ee7a hai hi\u1ec7u \u1ee9ng n\u00e0y \u0111\u00e3 d\u1eabn t\u1edbi s\u1ef1 h\u00ecnh th\u00e0nh c\u1ee7a hai ch\u1ed7 ph\u00ecnh c\u1ee7a \u0111\u1ea1i d\u01b0\u01a1ng. Th\u1ee9 nh\u1ea5t, c\u00f3 m\u1ed9t ch\u1ed7 ph\u00ecnh d\u1ec5 hi\u1ec3u \u1edf m\u1eb7t g\u1ea7n m\u1eb7t tr\u0103ng nh\u1ea5t c\u1ee7a tr\u00e1i \u0111\u1ea5t; k\u1ebf \u0111\u00f3 l\u00e0 ch\u1ed7 ph\u00ecnh th\u1ee9 hai \u1edf m\u1eb7t b\u00ean kia, h\u00ecnh th\u00e0nh b\u1edfi hi\u1ec7u \u1ee9ng ly t\u00e2m v\u00e0 b\u1edfi t\u00e1c \u0111\u1ed9ng nh\u1ecf c\u1ee7a tr\u1ecdng tr\u01b0\u1eddng m\u1eb7t tr\u0103ng. Khi tr\u00e1i \u0111\u1ea5t xoay, ch\u00fang ta s\u1ebd g\u1eb7p c\u1ea3 hai ch\u1ed7 ph\u00ecnh, th\u1ee9 m\u00e0 ta th\u01b0\u1eddng g\u1ecdi l\u00e0 th\u1ee7y tri\u1ec1u l\u00ean. Gi\u1ed1ng nh\u01b0 b\u1ea5t c\u1ee9 th\u1ee9 g\u00ec kh\u00e1c trong h\u1ec7 tr\u00e1i \u0111\u1ea5t-m\u1eb7t tr\u0103ng, nh\u1eefng chi ti\u1ebft c\u1ea7n thi\u1ebft cho vi\u1ec7c d\u1ef1 \u0111o\u00e1n th\u1ee7y tri\u1ec1u ch\u00ednh x\u00e1c th\u00ec ph\u1ee9c t\u1ea1p h\u01a1n nhi\u1ec1u (Isaac Newton \u0111\u00e3 than phi\u1ec1n r\u1eb1ng v\u1ea5n \u0111\u1ec1 \u0111\u00f3 ch\u00ednh l\u00e0 \u0111i\u1ec1u duy nh\u1ea5t \u0111\u00e3 l\u00e0m cho \u00f4ng m\u1eafc b\u1ec7nh \u0111au \u0111\u1ea7u). Ngo\u00e0i ra c\u00f2n c\u00f3 vai tr\u00f2 c\u1ee7a m\u1eb7t tr\u1eddi l\u00e0m t\u0103ng s\u1ee9c k\u00e9o c\u1ee7a m\u1eb7t tr\u0103ng trong nh\u1eefng l\u00fac tr\u0103ng tr\u00f2n, t\u1ea1o th\u00e0nh c\u01a1n th\u1ee7y tri\u1ec1u l\u1edbn. Kh\u00f4ng ch\u1ec9 c\u00f3 bi\u1ec3n c\u1ea3 l\u00e0 b\u1ecb t\u00e1c 90 https:\/\/thuviensach.vn","\u0111\u1ed9ng: hai l\u1ea7n m\u1ed9t ng\u00e0y, b\u1ec1 m\u1eb7t tr\u00e1i \u0111\u1ea5t c\u0169ng d\u00e2ng l\u00ean h\u1ea1 xu\u1ed1ng kho\u1ea3ng m\u1ed9t th\u01b0\u1edbc \u1edf \u0111\u01b0\u1eddng x\u00edch \u0111\u1ea1o. 69 Tr\u00e1i \u0111\u1ea5t b\u1ecb t\u00e1c \u0111\u1ed9ng b\u1edfi c\u00e1c h\u00e0nh tinh kh\u00e1c t\u1edbi m\u1ee9c \u0111\u1ed9 n\u00e0o? M\u1eb7c d\u00f9 c\u00e1c h\u00e0nh tinh c\u00f3 th\u1ec3 kh\u00f4ng t\u00e1c \u0111\u1ed9ng t\u1edbi ch\u00fang ta theo c\u00e1ch m\u00e0 c\u00e1c nh\u00e0 thi\u00ean v\u0103n h\u1ecdc mu\u1ed1n ch\u00fang ta tin, c\u00e1c s\u1ef1 ki\u1ec7n tr\u00ean tr\u00e1i \u0111\u1ea5t th\u00ec v\u1eabn ch\u1eafc ch\u1eafn l\u00e0 b\u1ecb \u1ea3nh h\u01b0\u1edfng b\u1edfi l\u1ef1a h\u1ea5p d\u1eabn c\u1ee7a c\u00e1c thi\u00ean th\u1ec3 l\u00e1ng gi\u1ec1ng c\u1ee7a ch\u00fang ta, v\u00e0 h\u1eadu qu\u1ea3 th\u00ec th\u1eadt s\u1ef1 nghi\u00eam tr\u1ecdng. S\u1ef1 \u0111\u1ea9y v\u00e0 k\u00e9o b\u1edfi c\u00e1c h\u00e0nh tinh kh\u00e1c, ch\u1ee7 y\u1ebfu l\u00e0 sao M\u1ed9c v\u00e0 v\u00e0 sao Kim, l\u00e0m thay \u0111\u1ed5i k\u00edch th\u01b0\u1edbc, h\u00ecnh d\u1ea1ng v\u00e0 h\u01b0\u1edbng c\u1ee7a qu\u1ef9 \u0111\u1ea1o tr\u00e1i \u0111\u1ea5t. Trong khi tr\u1ee5c c\u1ee7a qu\u1ef9 \u0111\u1ea1o tr\u00e1i \u0111\u1ea5t th\u00ec dao \u0111\u1ed9ng xung quanh d\u01b0\u1edbi t\u00e1c \u0111\u1ed9ng li\u00ean k\u1ebft c\u1ee7a m\u1eb7t tr\u1eddi v\u00e0 m\u1eb7t tr\u0103ng. Ba trong s\u1ed1 nh\u1eefng t\u00e1c \u0111\u1ed9ng sau \u0111\u00e2y l\u00e0 \u0111\u1eb7c bi\u1ec7t quan tr\u1ecdng. Th\u1ee9 nh\u1ea5t, s\u1ef1 l\u1ec7ch t\u00e2m c\u1ee7a qu\u1ef9 \u0111\u1ea1o tr\u00e1i \u0111\u1ea5t - t\u1ee9c l\u00e0 s\u1ef1 tu\u1ea7n ho\u00e0n k\u00e9m ho\u00e0n h\u1ea3o - thay \u0111\u1ed5i t\u1eeb g\u1ea7n zero t\u1edbi 0,12% m\u1ed7i 100 ng\u00e0n n\u0103m. Th\u1ee9 hai, s\u1ef1 nghi\u00eang t\u01b0\u01a1ng \u0111\u1ed1i c\u1ee7a tr\u1ee5c tr\u00e1i \u0111\u1ea5t so v\u1edbi qu\u1ef9 \u0111\u1ea1o c\u1ee7a n\u00f3 c\u0169ng thay \u0111\u1ed5i, t\u1eeb gi\u00e1 tr\u1ecb hi\u1ec7n t\u1ea1i kho\u1ea3ng 23,50 xu\u1ed1ng t\u1edbi m\u1ee9c 21,60 v\u00e0 l\u00ean t\u1edbi m\u1ee9c 24,50 qua m\u1ed7i 41 ng\u00e0n n\u0103m. Cu\u1ed1i c\u00f9ng, th\u1eddi gian m\u00e0 tr\u00e1i \u0111\u1ea5t ti\u1ebfn g\u1ea7n m\u1eb7t tr\u1eddi nh\u1ea5t b\u1ecb t\u00e1c \u0111\u1ed9ng b\u1edfi c\u00e1c h\u00e0nh tinh kh\u00e1c, m\u1eb7t tr\u1eddi v\u00e0 m\u1eb7t tr\u0103ng. Ng\u00e0y nay, tr\u00e1i \u0111\u1ea5t \u0111\u1ebfn g\u1ea7n m\u1eb7t tr\u1eddi nh\u1ea5t v\u00e0o \u0111\u1ea7u th\u00e1ng 1, khi b\u1eafc b\u00e1n c\u1ea7u \u0111ang nghi\u00eang ra xa m\u1eb7t tr\u1eddi. Tuy nhi\u00ean, kho\u1ea3ng 11.500 n\u0103m sau, tr\u1ee5c 91 https:\/\/thuviensach.vn","c\u1ee7a tr\u00e1i \u0111\u1ea5t \u0111\u00e3 b\u1ecb k\u00e9o l\u1ea1i, do \u0111\u00f3 b\u1eafc b\u00e1n c\u1ea7u s\u1ebd h\u01b0\u1edbng v\u1ec1 ph\u00eda m\u1eb7t tr\u1eddi khi tr\u00e1i \u0111\u1ea5t \u0111ang \u0111\u1ebfn g\u1ea7n m\u1eb7t tr\u1eddi nh\u1ea5t. Ngo\u1ea1i tr\u1eeb vi\u1ec7c chuy\u1ec3n Gi\u00e1ng sinh v\u1ec1 gi\u1eefa m\u00f9a h\u00e8 \u1edf ph\u01b0\u01a1ng b\u1eafc, nh\u1eefng thay \u0111\u1ed5i c\u00f3 chu k\u1ef3 n\u00e0y, \u0111\u01b0\u1ee3c bi\u1ebft d\u01b0\u1edbi t\u00ean l\u00e0 chu k\u1ef3 Milankovitch, \u0111\u01b0\u1ee3c tin l\u00e0 c\u00f3 nh\u1eefng t\u00e1c \u0111\u1ed9ng s\u00e2u s\u1eafc t\u1edbi kh\u00ed h\u1eadu tr\u00e1i \u0111\u1ea5t, b\u1eb1ng vi\u1ec7c thay \u0111\u1ed5i l\u01b0\u1ee3ng nhi\u1ec7t c\u1ee7a m\u1eb7t tr\u1eddi \u0111\u1ebfn \u0111\u01b0\u1ee3c h\u00e0nh tinh n\u00e0y. T\u00e1c \u0111\u1ed9ng tr\u1ef1c ti\u1ebfp l\u00e0 r\u1ea5t nh\u1ecf nh\u01b0ng s\u1ef1 nh\u1ea1y c\u1ea3m c\u1ee7a kh\u00ed h\u1eadu tr\u00e1i \u0111\u1ea5t s\u1ebd d\u1eabn t\u1edbi nh\u1eefng h\u1eadu qu\u1ea3 nghi\u00eam tr\u1ecdng. C\u00e1c chu k\u1ef3 Milankovitch ng\u00e0y nay \u0111\u01b0\u1ee3c cho l\u00e0 c\u00f3 vai tr\u00f2 trong s\u1ef1 xu\u1ea5t hi\u1ec7n v\u00e0 suy t\u00e0n c\u1ee7a K\u1ef7 b\u0103ng h\u00e0, v\u00e0 g\u1ea7n \u0111\u00e2y \u0111\u00e3 \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi nh\u1eefng thay \u0111\u1ed5i \u0111\u1ed9t ng\u1ed9t c\u1ee7a kh\u00ed h\u1eadu \u0111\u00e3 d\u1eabn t\u1edbi s\u1ef1 h\u00ecnh th\u00e0nh sa m\u1ea1c Sahara, c\u00e1ch \u0111\u00e2y kho\u1ea3ng 5.500 n\u0103m. 70 Thi\u00ean th\u1ea1ch c\u00f3 g\u00e2y ra ti\u1ebfng \u0111\u1ed9ng khi ch\u00fang r\u01a1i v\u00e0o tr\u00e1i \u0111\u1ea5t kh\u00f4ng? \u0110i v\u00e0o kh\u00ed quy\u1ec3n tr\u00e1i \u0111\u1ea5t \u1edf t\u1ed1c \u0111\u1ed9 18.000m\/s ho\u1eb7c h\u01a1n n\u1eefa, h\u1ea7u h\u1ebft c\u00e1c kh\u1ed1i m\u1ea3nh v\u1ee1 v\u0169 tr\u1ee5 n\u00e0y \u0111\u1ec1u ch\u00e1y h\u1ebft \u1edf qu\u00e1 cao \u0111\u1ec3 sinh ra b\u1ea5t c\u1ee9 ti\u1ebfng \u0111\u1ed9ng n\u00e0o m\u00e0 ch\u00fang ta c\u00f3 th\u1ec3 nghe th\u1ea5y t\u1eeb m\u1eb7t \u0111\u1ea5t. C\u00f2n c\u00e1c thi\u00ean th\u1ec3 m\u00e0 x\u00e2m nh\u1eadp s\u00e2u v\u00e0o kh\u00ed quy\u1ec3n th\u00ec t\u1ea1o ra m\u1ed9t s\u00f3ng ch\u1ea5n \u0111\u1ed9ng b\u1edfi kh\u00f4ng kh\u00ed b\u1ecb n\u00e9n \u1edf ph\u00eda tr\u01b0\u1edbc ch\u00fang, v\u00e0 c\u00f3 th\u1ec3 \u0111\u1ebfn \u0111\u01b0\u1ee3c m\u1eb7t \u0111\u1ea5t nh\u01b0 m\u1ed9t qu\u1ea3 bom \u00e2m thanh nghe \u0111\u01b0\u1ee3c. 92 https:\/\/thuviensach.vn","Trong nhi\u1ec1u tr\u01b0\u1eddng h\u1ee3p, s\u1ef1 n\u00e9n kh\u00ed \u0111\u1ed9ng h\u1ecdc l\u1edbn t\u1edbi m\u1ee9c c\u00e1c sao b\u0103ng n\u1ed5 ra trong kh\u00f4ng trung, v\u1edbi m\u1ed9t t\u00e1c \u0111\u1ed9ng nghi\u00eam tr\u1ecdng. N\u0103m 1999, c\u00e1c nh\u00e0 khoa h\u1ecdc \u1edf ph\u00e2n vi\u1ec7n \u0111\u1ecba ch\u1ea5n h\u1ecdc c\u1ee7a Vi\u1ec7n thi\u00ean th\u1ea1ch h\u1ecdc ho\u00e0ng gia H\u00e0 Lan \u0111\u00e3 ph\u00e1t hi\u1ec7n c\u00e1c s\u00f3ng h\u1ea1 \u00e2m ph\u00e1t ra b\u1edfi m\u1ed9t sao b\u0103ng b\u1ecb v\u1ee1 \u1edf \u0111\u1ed9 cao kho\u1ea3ng 15.000 m\u00e9t, v\u1edbi s\u1ef1 m\u00e3nh li\u1ec7t c\u1ee7a m\u1ed9t qu\u1ea3 bom nguy\u00ean t\u1eed nh\u1ecf. \u0110\u00f4i khi c\u00e1c v\u1ee5 n\u1ed5 trong kh\u00f4ng kh\u00ed n\u00e0y c\u00f3 th\u1ec3 nghe tr\u1ef1c ti\u1ebfp \u0111\u01b0\u1ee3c, theo nh\u01b0 ph\u00e1t hi\u1ec7n c\u1ee7a c\u00e1c c\u01b0 d\u00e2n m\u1ed9t v\u00f9ng xa x\u00f4i \u1edf \u0111\u1ea3o b\u1eafc New Zealand v\u00e0o ng\u00e0y 8 th\u00e1ng 7 n\u0103m 1999. Hi\u1ebfm h\u01a1n n\u1eefa, sao b\u0103ng t\u00ecm \u0111\u01b0\u1ee3c \u0111\u01b0\u1eddng xu\u1ed1ng t\u1edbi tr\u00e1i \u0111\u1ea5t v\u00e0 chuy\u1ec3n th\u00e0nh c\u00e1c \u201cthi\u00ean th\u1ea1ch\u201d b\u1eb1ng vi\u1ec7c va v\u00e0o m\u1eb7t \u0111\u1ea5t nh\u01b0 m\u1ed9t qu\u1ea3 \u0111\u1ea5m m\u1ea1nh. \u0110i\u1ec1u \u0111\u00e1ng bu\u1ed3n l\u00e0 hi\u1ebfm c\u00f3 ai \u1edf quanh \u0111\u00f3 \u0111\u1ec3 nghe n\u00f3 v\u00e0 s\u1ef1 t\u1edbi n\u01a1i c\u1ee7a m\u1ed9t ngu\u1ed3n v\u1eadt ch\u1ea5t li\u00ean h\u00e0nh tinh qu\u00fd gi\u00e1 kh\u00e1c \u0111\u00e3 kh\u00f4ng \u0111\u01b0\u1ee3c ph\u00e1t hi\u1ec7n. 71 V\u1eadt th\u1ec3 xa nh\u1ea5t c\u00f3 th\u1ec3 th\u1ea5y \u0111\u01b0\u1ee3c b\u1eb1ng m\u1eaft th\u01b0\u1eddng l\u00e0 g\u00ec? \u0110\u00e2y l\u00e0 m\u1ed9t trong nh\u1eefng c\u00e2u \u0111\u1ed1 m\u1eb9o th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111\u1eb7t ra d\u01b0\u1edbi d\u1ea1ng \u201cB\u1ea1n c\u00f3 th\u1ec3 nh\u00ecn xa bao nhi\u00eau v\u1edbi m\u1eaft tr\u1ea7n?\u201d. B\u1ea1n c\u00f3 th\u1ec3 ngh\u0129 ra n\u00f3 v\u00e0o kho\u1ea3ng 160km, gi\u1ea3 s\u1eed l\u00e0 t\u1eeb \u0111\u1ec9nh Everest hay \u0111i\u1ec3m n\u00e0o \u0111\u00f3 cao g\u1ea7n nh\u01b0 v\u1eady. 93 https:\/\/thuviensach.vn","C\u00e2u tr\u1ea3 l\u1eddi th\u1ef1c s\u1ef1 ph\u1ee5 thu\u1ed9c v\u00e0o t\u1ea7m m\u1eaft c\u1ee7a b\u1ea1n t\u1ed1t t\u1edbi m\u1ee9c n\u00e0o nh\u01b0ng xa h\u01a1n nhi\u1ec1u so v\u1edbi b\u1ea1n ngh\u0129. B\u1ea5t c\u1ee9 ai v\u1edbi t\u1ea7m nh\u00ecn trung b\u00ecnh c\u0169ng c\u00f3 th\u1ec3 nh\u00ecn th\u1ea5y thi\u00ean h\u00e0 trong ch\u00f2m sao Ti\u00ean n\u1eef (Andromeda), c\u00e1ch tr\u00e1i \u0111\u1ea5t kho\u1ea3ng 2.200.000 n\u0103m \u00e1nh s\u00e1ng hay kho\u1ea3ng 20 t\u1ec9 t\u1ec9 km. C\u00f2n nh\u1eefng ai v\u1edbi t\u1ea7m nh\u00ecn th\u1ef1c s\u1ef1 t\u1ed1t th\u00ec th\u1eadm ch\u00ed c\u00f2n c\u00f3 th\u1ec3 nh\u00ecn tho\u00e1ng qua c\u0169ng th\u1ea5y thi\u00ean h\u00e0 M33 trong ch\u00f2m sao Tam gi\u00e1c (Triangulum). Thi\u00ean h\u00e0 n\u00e0y ch\u1ec9 c\u00f3 th\u1ec3 nh\u00ecn th\u1ea5y khi b\u1ea7u tr\u1eddi th\u1eadt s\u1ef1 trong v\u00e0 n\u00f3 c\u00e1ch xa tr\u00e1i \u0111\u1ea5t 3.000.000 n\u0103m \u00e1nh s\u00e1ng, g\u1ea7n g\u1ea5p r\u01b0\u1ee1i so v\u1edbi ch\u00f2m sao Ti\u00ean n\u1eef. 72 Khi m\u1ed9t thi\u00ean th\u1ea1ch \u0111\u1ebfn g\u1ea7n tr\u00e1i \u0111\u1ea5t, t\u1ea1i sao l\u1ef1c h\u1ea5p d\u1eabn kh\u00f4ng k\u00e9o n\u00f3 v\u00e0o v\u00e0 g\u00e2y n\u00ean m\u1ed9t c\u00fa va ch\u1ea1m? Tr\u00e1i \u0111\u1ea5t \u0111\u00e3 su\u00fdt l\u00e2m nguy v\u00e0o n\u0103m 2002, khi m\u1ed9t thi\u00ean th\u1ea1ch r\u1ed9ng kho\u1ea3ng 100m, t\u00ean l\u00e0 2002MN, \u0111\u1ebfn g\u1ea7n 120.000km so v\u1edbi tr\u00e1i \u0111\u1ea5t. N\u1ebfu l\u00fac \u0111\u00f3 n\u00f3 va v\u00e0o tr\u00e1i \u0111\u1ea5t, c\u00fa va ch\u1ea1m s\u1ebd c\u00f3 s\u1ee9c m\u1ea1nh h\u1ee7y di\u1ec7t c\u1ee7a g\u1ea7n m\u1ed9t ch\u1ee5c qu\u1ea3 bom khinh kh\u00ed (H-bomb). Theo c\u00e1ch n\u00f3i th\u01b0\u1eddng ng\u00e0y, 120.000km d\u01b0\u1eddng nh\u01b0 l\u00e0 m\u1ed9t kho\u1ea3ng c\u00e1ch 94 https:\/\/thuviensach.vn","r\u1ea5t l\u1edbn nh\u01b0ng tr\u1ecdng l\u1ef1c c\u1ee7a tr\u00e1i \u0111\u1ea5t v\u1eabn c\u00f2n m\u1ed9t v\u00e0i \u1ea3nh h\u01b0\u1edfng c\u00f2n xa h\u01a1n nhi\u1ec1u trong kh\u00f4ng gian (b\u1eb1ng ch\u1ee9ng l\u00e0 m\u1eb7t tr\u0103ng c\u1ee7a ch\u00fang ta, v\u1edbi kho\u1ea3ng c\u00e1ch xa h\u01a1n g\u1ea5p ba l\u1ea7n). L\u00fd do khi\u1ebfn 2002MN tr\u01b0\u1ee3t kh\u1ecfi t\u1ea7m ng\u1eafm c\u1ee7a tr\u00e1i \u0111\u1ea5t l\u00e0 chuy\u1ec3n \u0111\u1ed9ng t\u01b0\u01a1ng \u0111\u1ed1i c\u1ee7a n\u00f3 so v\u1edbi tr\u00e1i \u0111\u1ea5t th\u00ec qu\u00e1 nhanh - kho\u1ea3ng 10.000 m\/s - \u0111\u1ebfn n\u1ed7i n\u00f3 \u0111\u00e3 c\u00f3 \u0111\u1ee7 n\u0103ng l\u01b0\u1ee3ng \u0111\u1ec3 tho\u00e1t ra kh\u1ecfi \u201cgi\u1ebfng tr\u1ecdng l\u1ef1c\u201d c\u1ee7a tr\u00e1i \u0111\u1ea5t v\u00e0 tr\u1edf v\u1ec1 v\u1edbi kh\u00f4ng gian s\u00e2u th\u1eb3m. M\u1ed9t t\u00ednh to\u00e1n nhanh cho th\u1ea5y r\u1eb1ng 2002MN ph\u1ea3i t\u1edbi g\u1ea7n 3.200km so v\u1edbi m\u1eb7t \u0111\u1ea5t \u0111\u1ec3 c\u00f3 th\u1ec3 b\u1ecb h\u00fat v\u00e0o v\u00e0 g\u00e2y ra m\u1ed9t v\u1ee5 va ch\u1ea1m. H\u1ea7u h\u1ebft c\u00e1c thi\u00ean th\u1ea1ch c\u00f3 m\u1ed9t t\u1ed1c \u0111\u1ed9 c\u00f2n cao h\u01a1n v\u00e0 ph\u1ea3i \u0111\u1ebfn g\u1ea7n 1.600 km so v\u1edbi tr\u00e1i \u0111\u1ea5t \u0111\u1ec3 va v\u00e0o \u0111\u01b0\u1ee3c ch\u00fang ta. Tuy nhi\u00ean, \u0111\u00f3 ch\u1ec9 l\u00e0 v\u1ea5n \u0111\u1ec1 th\u1eddi gian cho t\u1edbi khi c\u00f3 m\u1ed9t thi\u00ean th\u1ec3 l\u00e0m \u0111\u01b0\u1ee3c \u0111i\u1ec1u \u0111\u00f3. 73 Th\u1eddi \u0111i\u1ec3m ch\u00ednh x\u00e1c c\u1ee7a m\u1eb7t tr\u1eddi m\u1ecdc v\u00e0 m\u1eb7t tr\u1eddi l\u1eb7n \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh nh\u01b0 th\u1ebf n\u00e0o? N\u1ebfu cho r\u1eb1ng thi\u00ean v\u0103n h\u1ecdc l\u00e0 m\u1ed9t khoa h\u1ecdc l\u00e2u \u0111\u1eddi nh\u1ea5t v\u00e0 m\u1eb7t tr\u1eddi m\u1ecdc v\u00e0 l\u1eb7n l\u00e0 nh\u1eefng hi\u1ec7n t\u01b0\u1ee3ng thi\u00ean nhi\u00ean h\u1ebft s\u1ee9c c\u0103n b\u1ea3n, c\u00f3 th\u1ec3 b\u1ea1n s\u1ebd ngh\u0129 r\u1eb1ng c\u00e2u h\u1ecfi n\u00e0y \u0111\u00e3 \u0111\u01b0\u1ee3c gi\u1ea3i quy\u1ebft nhi\u1ec1u th\u1ebf k\u1ef7 tr\u01b0\u1edbc. Ho\u00e0n to\u00e0n 95 https:\/\/thuviensach.vn","kh\u00f4ng ph\u1ea3i v\u1eady. Ch\u00fang ta s\u1ed1ng tr\u00ean m\u1ed9t qu\u1ea3 c\u1ea7u \u0111\u00e1 bao quanh b\u1edfi kh\u00f4ng kh\u00ed, \u0111i\u1ec1u n\u00e0y khi\u1ebfn cho vi\u1ec7c ch\u1ec9 ra ch\u00ednh x\u00e1c th\u1eddi \u0111i\u1ec3m m\u1eb7t tr\u1eddi m\u1ecdc v\u00e0 l\u1eb7n l\u00e0 r\u1ea5t kh\u00f3 kh\u0103n. V\u00ed d\u1ee5, ph\u1ea7n n\u00e0o c\u1ee7a m\u1eb7t tr\u1eddi s\u1ebd h\u00e9 qua \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi v\u00e0 \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi n\u00e0o: m\u1ed9t b\u1ec1 m\u1eb7t t\u01b0\u1edfng t\u01b0\u1ee3ng ph\u1eb3ng ho\u00e0n h\u1ea3o hay b\u1ec1 m\u1eb7t c\u00f3 t\u00ednh t\u1edbi c\u00e1c \u0111i\u1ec1u ki\u1ec7n c\u1ee7a \u0111\u1ecba ph\u01b0\u01a1ng nh\u01b0 thung l\u0169ng v\u00e0 n\u00fai? H\u01a1n n\u1eefa, ch\u00fang ta ch\u1ec9 c\u00f3 th\u1ec3 th\u1ea5y m\u1eb7t tr\u1eddi sau khi \u00e1nh s\u00e1ng c\u1ee7a n\u00f3 \u0111i xuy\u00ean qua kh\u00ed quy\u1ec3n tr\u00e1i \u0111\u1ea5t. S\u1ef1 kh\u00fac x\u1ea1 sau \u0111\u00f3 c\u00f3 ngh\u0129a l\u00e0 m\u1eb7t tr\u1eddi kh\u00f4ng th\u1ef1c s\u1ef1 \u1edf n\u01a1i n\u00f3 c\u00f3 v\u1ebb nh\u01b0 \u0111ang \u0111\u1ee9ng. M\u00e0 hi\u1ec7u \u1ee9ng kh\u00fac x\u1ea1 n\u00e0y l\u1ea1i thay \u0111\u1ed5i theo v\u0129 \u0111\u1ed9 v\u00e0 c\u00e1c \u0111i\u1ec1u ki\u1ec7n th\u1eddi ti\u1ebft. Nh\u1eefng nh\u00e0 thi\u00ean v\u0103n h\u1ecdc gi\u1ecfi nh\u1ea5t cu\u1ed1i c\u00f9ng \u0111\u00e3 ch\u1ecdn \u0111\u1ecbnh ngh\u0129a m\u1eb7t tr\u1eddi m\u1ecdc v\u00e0 l\u1eb7n l\u00e0 th\u1eddi \u0111i\u1ec3m m\u00e0 t\u00e2m m\u1eb7t tr\u1eddi t\u1ea1o th\u00e0nh m\u1ed9t g\u00f3c 90,83330 v\u1edbi thi\u00ean \u0111\u1ec9nh, t\u1ee9c l\u00e0 \u0111i\u1ec3m n\u1eb1m ngay tr\u00ean \u0111\u1ea7u ng\u01b0\u1eddi quan s\u00e1t. \u0110i\u1ec1u n\u00e0y \u0111\u00e3 lo\u1ea1i tr\u1eeb \u0111\u01b0\u1ee3c v\u1ea5n \u0111\u1ec1 h\u00f3c b\u00faa trong vi\u1ec7c x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi chu\u1ea9n nh\u01b0ng t\u1ea1i sao g\u00f3c \u0111\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 \u0111\u00fang 900? Th\u1ee9 nh\u1ea5t, trung b\u00ecnh trong v\u00f2ng m\u1ed9t n\u0103m, m\u1eb7t tr\u1eddi d\u01b0\u1eddng nh\u01b0 che ph\u1ee7 m\u1ed9t v\u00f9ng 0,533330 c\u1ee7a b\u1ea7u tr\u1eddi, v\u1eady n\u00ean kho\u1ea3ng c\u00e1ch gi\u1eefa t\u00e2m m\u1eb7t tr\u1eddi v\u00e0 b\u1edd c\u1ee7a n\u00f3 l\u00e0 kho\u1ea3ng m\u1ed9t n\u1eeda s\u1ed1 \u0111\u00f3, t\u1ee9c l\u00e0 0,266670. Th\u1ee9 hai, kh\u00ed quy\u1ec3n tr\u00e1i \u0111\u1ea5t b\u1ebb cong \u00e1nh s\u00e1ng m\u1eb7t tr\u1eddi trung b\u00ecnh kho\u1ea3ng 0,566660 v\u00e0 s\u1ed1 n\u00e0y ph\u1ea3i \u0111\u01b0\u1ee3c c\u1ed9ng v\u00e0o b\u00e1n k\u00ednh m\u1eb7t tr\u1eddi \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o s\u1ef1 tr\u00f9ng kh\u1edbp gi\u1eefa b\u1ec1 ngo\u00e0i v\u00e0 th\u1ef1c t\u1ebf, t\u1ea1o n\u00ean con s\u1ed1 cu\u1ed1i c\u00f9ng l\u00e0 0,83330. Do \u0111\u00f3, vi\u1ec7c x\u00e1c \u0111\u1ecbnh th\u1eddi \u0111i\u1ec3m m\u1eb7t tr\u1eddi m\u1ecdc v\u00e0 l\u1eb7n n\u00e0y c\u00f3 v\u1ebb nh\u01b0 l\u00e0 m\u1ed9t s\u1ef1 ch\u1ea5p v\u00e1 v\u1ee5ng v\u1ec1, \u0111\u1eb7t c\u01a1 s\u1edf tr\u00ean 96 https:\/\/thuviensach.vn","trung b\u00ecnh n\u0103m v\u00e0 b\u1ecf qua c\u00e1c \u0111i\u1ec1u ki\u1ec7n \u0111\u1ecba ph\u01b0\u01a1ng. V\u1eady n\u00ean, th\u1eddi \u0111i\u1ec3m m\u1eb7t tr\u1eddi m\u1ecdc v\u00e0 l\u1eb7n kh\u00f4ng th\u1ec3 \u0111\u01b0\u1ee3c d\u1ef1 b\u00e1o ch\u00ednh x\u00e1c cho b\u1ea5t k\u1ef3 \u0111\u1ecba ph\u01b0\u01a1ng n\u00e0o (\u0111\u1eb7c bi\u1ec7t l\u00e0 \u1edf c\u00e1c v\u0129 \u0111\u1ed9 t\u01b0\u01a1ng \u0111\u1ed1i cao, n\u01a1i m\u00e0 hi\u1ec7u \u1ee9ng kh\u00fac x\u1ea1 kh\u00e1 m\u1ea1nh) v\u00e0 c\u00e1c gi\u00e1 tr\u1ecb \u0111\u01b0\u1ee3c \u0111\u0103ng tr\u00ean c\u00e1c t\u1edd b\u00e1o c\u00f3 th\u1ec3 tr\u1edf th\u00e0nh sai ch\u1ec9 trong v\u00f2ng m\u1ed9t v\u00e0i ph\u00fat sau khi \u0111\u0103ng. 74 C\u00f3 tr\u01b0\u1eddng h\u1ee3p n\u00e0o phi thuy\u1ec1n b\u1ecb ph\u00e1 h\u1ecfng b\u1edfi \u201cm\u1ea3nh v\u1ee1 kh\u00f4ng gian\u201d kh\u00f4ng? C\u00e1c tuy\u00ean b\u1ed1 r\u1eb1ng Tr\u1ea1m kh\u00f4ng gian qu\u1ed1c t\u1ebf c\u00f3 th\u1ec3 b\u1ecb ph\u00e1 h\u1ee7y b\u1edfi s\u1ef1 va ch\u1ea1m c\u1ee7a m\u1ed9t vi\u00ean \u0111\u1ea1n kim lo\u1ea1i bay tr\u00ean qu\u1ef9 \u0111\u1ea1o th\u1ef1c s\u1ef1 c\u00f3 m\u1ed9t s\u1ed1 c\u01a1 s\u1edf. N\u0103ng l\u01b0\u1ee3ng trong m\u1ed9t c\u00fa va ch\u1ea1m nh\u01b0 v\u1eady th\u00ec th\u1ef1c s\u1ef1 l\u00e0 r\u1ea5t \u0111\u00e1ng s\u1ee3. \u1ede qu\u1ef9 \u0111\u1ea1o tr\u00e1i \u0111\u1ea5t th\u1ea5p, t\u1ed1c \u0111\u1ed9 va ch\u1ea1m trung b\u00ecnh l\u00e0 kho\u1ea3ng 1.000m\/s, m\u1ed9t t\u1ed1c \u0111\u1ed9 m\u00e0 s\u1ebd bi\u1ebfn ngay c\u1ea3 m\u1ed9t vi\u00ean \u0111\u1ea1n nh\u1ecf th\u00e0nh m\u1ed9t c\u00fa h\u00fac c\u00f3 kh\u1ea3 n\u0103ng h\u1ee7y di\u1ec7t c\u1ee7a m\u1ed9t chi\u1ebfc \u00f4t\u00f4 \u0111ang ch\u1ea1y kho\u1ea3ng h\u01a1n 200km\/h. V\u00e0 kh\u00f4ng h\u1ec1 thi\u1ebfu nh\u1eefng v\u1eadt th\u1ec3 c\u00f3 th\u1ec3 t\u1ea1o ra m\u1ed9t c\u00fa va ch\u1ea1m kinh kh\u1ee7ng nh\u01b0 v\u1eady. C\u00e1c nh\u00e0 thi\u00ean v\u0103n h\u1ecdc \u01b0\u1edbc t\u00ednh r\u1eb1ng c\u00f3 kho\u1ea3ng 100.000 m\u1ea3nh kim lo\u1ea1i v\u1edbi chi\u1ec1u ngang t\u1eeb 1 t\u1edbi 10 cm \u0111ang bay l\u01a1 l\u1eedng xung quanh qu\u1ef9 \u0111\u1ea1o tr\u00e1i \u0111\u1ea5t. 97 https:\/\/thuviensach.vn","Th\u1eadt may m\u1eafn, cho \u0111\u1ebfn gi\u1edd, m\u1ed1i \u0111e do\u1ea1 t\u1eeb c\u00e1c m\u1ea3nh v\u1ee1 kh\u00f4ng gian v\u1eabn ch\u01b0a g\u00e2y ra nhi\u1ec1u c\u00fa va ch\u1ea1m l\u1eafm. Li\u00ean X\u00f4 (c\u0169) \u0111\u00e3 nghi ng\u1edd r\u1eb1ng s\u1ef1 bi\u1ebfn m\u1ea5t \u0111\u1ea7y b\u00ed \u1ea9n c\u1ee7a v\u1ec7 tinh Kosmos 1275 n\u0103m 1981 c\u1ee7a h\u1ecd l\u00e0 k\u1ebft qu\u1ea3 c\u1ee7a m\u1ed9t s\u1ef1 va ch\u1ea1m v\u1edbi c\u00e1c m\u1ea3nh v\u1ee1 kh\u00f4ng gian. Nh\u01b0ng tr\u01b0\u1eddng h\u1ee3p \u0111\u1ea7u ti\u00ean \u0111\u01b0\u1ee3c x\u00e1c nh\u1eadn l\u00e0 v\u00e0o th\u00e1ng 7 n\u0103m 1996, khi m\u1ed9t v\u1ec7 tinh gi\u00e1n \u0111i\u1ec7p c\u1ee7a Ph\u00e1p b\u1ecb va ph\u1ea3i b\u1edfi m\u1ed9t m\u1ea3nh kim lo\u1ea1i bay \u1edf t\u1ed1c \u0111\u1ed9 14.000m\/s. \u0110\u01b0\u1ee3c \u0111\u1eb7t t\u00ean l\u00e0 Cerise, chi\u1ebfc v\u1ec7 tinh n\u1eb7ng h\u01a1n 45kg \u0111\u01b0\u1ee3c ph\u00f3ng l\u00ean n\u0103m 1995 \u0111\u1ec3 nghe tr\u1ed9m c\u00e1c li\u00ean l\u1ea1c \u0111i\u1ec7n t\u1eed c\u1ee7a c\u00e1c ch\u00ednh ph\u1ee7 n\u01b0\u1edbc ngo\u00e0i. K\u1ebb t\u1ea5n c\u00f4ng n\u00f3 l\u00e0 m\u1ed9t kh\u1ed1i c\u00f3 k\u00edch th\u01b0\u1edbc m\u1ed9t g\u00f3i ng\u0169 c\u1ed1c nh\u1ecf c\u1ee7a t\u00ean l\u1eeda n\u00e2ng \u0111\u1ee1 Aria ph\u00f3ng l\u00ean v\u00e0o n\u0103m 1986. Th\u1eadt ng\u1ea1c nhi\u00ean, b\u1ea5t k\u1ec3 h\u1ec7 th\u1ed1ng gi\u1eef th\u0103ng b\u1eb1ng c\u1ee7a c\u00f3 \u0111\u00e3 b\u1ed1c h\u01a1i sau c\u00fa va ch\u1ea1m, b\u1ed9 \u0111i\u1ec1u khi\u1ec3n c\u1ee7a Cerise v\u1eabn c\u00f3 th\u1ec3 v\u00e1 n\u00f3 l\u1ea1i v\u00e0 ti\u1ebfp t\u1ee5c nhi\u1ec7m v\u1ee5. Cho t\u1edbi gi\u1edd, nh\u1eefng ng\u01b0\u1eddi M\u1ef9 kh\u00f4ng ngh\u0129 h\u1ecd \u0111\u00e3 m\u1ea5t b\u1ea5t c\u1ee9 m\u1ed9t phi thuy\u1ec1n n\u00e0o b\u1edfi c\u00e1c m\u1ea3nh v\u1ee1 kh\u00f4ng gian. Trong khi c\u00e1c tr\u01b0\u1eddng h\u1ee3p hi h\u1eefu \u0111\u00f3 kh\u00f4ng th\u1ef1c s\u1ef1 \u0111\u1eb7t ra m\u1ed9t m\u1ed1i \u0111e d\u1ecda, ta v\u1eabn ph\u1ea3i e ng\u1ea1i m\u1ed9t \u201chi\u1ec7u \u1ee9ng th\u00e1c \u0111\u1ed5\u201d, trong \u0111\u00f3 khi m\u1ed9t c\u00fa va ch\u1ea1m ph\u00e1 h\u1ee7y m\u1ed9t phi thuy\u1ec1n, n\u00f3 t\u1ea1o ra r\u1ea5t nhi\u1ec1u m\u1ea3nh v\u1ee1 m\u00e0 sau \u0111\u00f3 l\u1ea1i ph\u00e1 h\u1ee7y c\u00e1c phi thuy\u1ec1n kh\u00e1c v\u00e0 c\u1ee9 ti\u1ebfp t\u1ee5c nh\u01b0 v\u1eady, trong m\u1ed9t ph\u1ea3n \u1ee9ng d\u00e2y chuy\u1ec1n h\u1ee7y di\u1ec7t. \u0110\u00e3 c\u00f3 nhi\u1ec1u \u0111\u1ec1 xu\u1ea5t nh\u1eb1m \u0111\u1ea9y l\u00f9i tai h\u1ecda ti\u1ec1m t\u00e0ng n\u00e0y b\u1eb1ng c\u00e1ch g\u1edfi l\u00ean nhi\u1ec1u v\u1ec7 tinh nh\u1ecf \u0111\u1ec3 d\u1ecdn d\u1eb9p v\u00f9ng v\u0169 tr\u1ee5 b\u00ean c\u1ea1nh ch\u00fang ta. Cho t\u1edbi gi\u1edd, c\u00e1c k\u1ebf ho\u1ea1ch d\u1ecdn d\u1eb9p nh\u01b0 v\u1eady \u0111\u00e3 \u0111\u01b0\u1ee3c h\u01b0\u1edfng \u1ee9ng r\u1ea5t nhi\u1ec7t t\u00ecnh. 98 https:\/\/thuviensach.vn","75 C\u00e1c phi h\u00e0nh gia \u1edf tr\u1ea1m kh\u00f4ng gian t\u00ecm \u0111\u00e2u ra kh\u00f4ng kh\u00ed? C\u00e1c phi h\u00e0nh gia l\u1ea7n \u0111\u1ea7u ti\u00ean \u0111i v\u00e0o Tr\u1ea1m kh\u00f4ng gian qu\u1ed1c t\u1ebf (International Space Station, ISS) c\u00e1ch \u0111\u00e2y h\u01a1n b\u1ed1n n\u0103m v\u00e0 t\u1eeb khi \u0111\u00f3 h\u1ecd \u0111\u00e3 \u0111\u01b0\u1ee3c cung c\u1ea5p oxygen t\u1ea1o ra t\u1eeb m\u1ed9t qu\u00e1 tr\u00ecnh \u0111\u01b0\u1ee3c ph\u00e1t hi\u1ec7n b\u1edfi nh\u00e0 h\u00f3a h\u1ecdc Wiliam Nicholson c\u00e1ch \u0111\u00e2y h\u01a1n 200 n\u0103m: qu\u00e1 tr\u00ecnh \u0111i\u1ec7n ph\u00e2n. N\u01b0\u1edbc \u0111\u01b0\u1ee3c v\u1eadn chuy\u1ec3n t\u1eeb tr\u00e1i \u0111\u1ea5t l\u00ean ISS, n\u01a1i m\u1ed9t b\u1ed9 m\u00e1y do Nga ch\u1ebf t\u1ea1o, Elektron, s\u1eed d\u1ee5ng \u0111i\u1ec7n n\u0103ng t\u1eeb c\u00e1c t\u1ea5m pin n\u0103ng l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi \u0111\u1ec3 ph\u00e2n c\u1eaft c\u00e1c ph\u00e2n t\u1eed n\u01b0\u1edbc th\u00e0nh oxygen v\u00e0 hyrogen, ph\u1ea7n oxygen n\u00e0y \u0111\u01b0\u1ee3c b\u01a1m v\u00e0o trong tr\u1ea1m c\u00f2n hydrogen s\u1ebd b\u1ecb phun v\u00e0o kh\u00f4ng gian. \u0110\u1ec3 cung c\u1ea5p m\u1ed9t b\u1ea7u kh\u00f4ng kh\u00ed an to\u00e0n, gi\u1ed1ng tr\u00e1i \u0111\u1ea5t v\u00e0 gi\u1eef m\u1ed9t m\u1ee9c \u0111\u1ed9 \u00e1p su\u1ea5t kh\u00f4ng kh\u00ed v\u1eeba ph\u1ea3i, kh\u00ed oxygen \u0111\u01b0\u1ee3c h\u00f2a tr\u1ed9n v\u1edbi m\u1ed9t ch\u1ea5t kh\u00ed t\u01b0\u01a1ng \u0111\u1ed1i tr\u01a1 l\u00e0 nitrogen trong nh\u1eefng chi\u1ebfc b\u1ed3n tr\u00ean tr\u1ea1m. Trong khi k\u1ef9 thu\u1eadt c\u0103n b\u1ea3n \u0111\u00e3 c\u00f3 t\u1eeb tr\u01b0\u1edbc th\u1eddi Victoria, s\u1ef1 t\u00e0i t\u00ecnh l\u00e0 \u1edf ch\u1ed7 t\u00e1ch cho \u0111\u1ebfn nh\u1eefng ng\u1ee5m oxygen cu\u1ed1i c\u00f9ng t\u1eeb n\u01b0\u1edbc: g\u1ea7n 98% n\u01b0\u1edbc s\u1eed d\u1ee5ng r\u1ed3i \u0111\u01b0\u1ee3c t\u00e1i ch\u1ebf - t\u1edbi c\u1ea3 nh\u1eefng l\u01b0\u1ee3ng m\u1ed3 h\u00f4i nh\u1ecf v\u00e0 h\u01a1i n\u01b0\u1edbc trong h\u01a1i th\u1edf c\u1ee7a c\u00e1c phi h\u00e0nh gia. Ngo\u00e0i Elektron ra tr\u1ea1m ISS c\u00f2n mang nh\u1eefng ngu\u1ed3n oxygen kh\u1ea9n c\u1ea5p trong c\u00e1c b\u1ed3n ch\u1ee9a, \u0111\u01b0\u1ee3c ch\u1ee9a 99 https:\/\/thuviensach.vn"]
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