\u0110\u1ecbnh ngh\u0129a chu\u1ea9n<\/strong><\/h3>\nTheo \u0111\u1ecbnh ngh\u0129a chu\u1ea9n c\u1ee7a H\u1ec7 \u0111o l\u01b0\u1eddng qu\u1ed1c t\u1ebf (SI), gi\u00e1 tr\u1ecb ch\u00ednh x\u00e1c c\u1ee7a t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng l\u00e0 <\/span>299.792.458 m\u00e9t\/gi\u00e2y<\/b>. Trong c\u00e1c t\u00ednh to\u00e1n th\u00f4ng th\u01b0\u1eddng ho\u1eb7c gi\u00e1o d\u1ee5c ph\u1ed5 th\u00f4ng, con s\u1ed1 n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c l\u00e0m tr\u00f2n th\u00e0nh 300.000 km\/s \u0111\u1ec3 d\u1ec5 nh\u1edb v\u00e0 thu\u1eadn ti\u1ec7n cho vi\u1ec7c \u01b0\u1edbc l\u01b0\u1ee3ng nhanh ch\u00f3ng. \u0110\u00e2y kh\u00f4ng ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 t\u1ed1c \u0111\u1ed9 di chuy\u1ec3n c\u1ee7a c\u00e1c h\u1ea1t photon m\u00e0 c\u00f2n l\u00e0 t\u1ed1c \u0111\u1ed9 gi\u1edbi h\u1ea1n tuy\u1ec7t \u0111\u1ed1i c\u1ee7a v\u0169 tr\u1ee5 \u0111\u1ed1i v\u1edbi m\u1ecdi v\u1eadt ch\u1ea5t v\u00e0 th\u00f4ng tin. \u0110\u1ec3 hi\u1ec3u s\u00e2u h\u01a1n v\u1ec1 \u0111i\u1ec1u n\u00e0y, ch\u00fang ta c\u1ea7n kh\u00e1m ph\u00e1 v\u1ec1 <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> m\u1ed9t c\u00e1ch chi ti\u1ebft.<\/span><\/p>\n![\"toc-do-anh-sang\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang.jpg\")
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Kh\u00e1i ni\u1ec7m v\u1ec1 t\u1ed1c \u0111\u1ed9 gi\u1edbi h\u1ea1n n\u00e0y \u0111\u00f3ng vai tr\u00f2 trung t\u00e2m trong n\u1ec1n t\u1ea3ng v\u1eadt l\u00fd l\u00fd thuy\u1ebft, \u0111\u1eb7c bi\u1ec7t l\u00e0 trong Thuy\u1ebft t\u01b0\u01a1ng \u0111\u1ed1i h\u1eb9p do nh\u00e0 v\u1eadt l\u00fd thi\u00ean t\u00e0i Albert Einstein c\u00f4ng b\u1ed1 v\u00e0o n\u0103m 1905. Theo l\u00fd thuy\u1ebft n\u00e0y, kh\u00f4ng m\u1ed9t v\u1eadt th\u1ec3 n\u00e0o c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ngh\u1ec9 d\u01b0\u01a1ng c\u00f3 th\u1ec3 \u0111\u1ea1t t\u1edbi ho\u1eb7c v\u01b0\u1ee3t qua t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong ch\u00e2n kh\u00f4ng. Khi m\u1ed9t v\u1eadt th\u1ec3 t\u0103ng t\u1ed1c \u0111\u1ed9 \u0111\u1ec3 ti\u1ec7m c\u1eadn v\u1edbi c, kh\u1ed1i l\u01b0\u1ee3ng t\u01b0\u01a1ng \u0111\u1ed1i t\u00ednh c\u1ee7a n\u00f3 s\u1ebd t\u0103ng l\u00ean v\u00f4 h\u1ea1n, \u0111\u00f2i h\u1ecfi m\u1ed9t ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng v\u00f4 t\u1eadn \u0111\u1ec3 ti\u1ebfp t\u1ee5c gia t\u1ed1c, \u0111i\u1ec1u n\u00e0y l\u00e0 b\u1ea5t kh\u1ea3 thi v\u1ec1 m\u1eb7t v\u1eadt l\u00fd.<\/span><\/p>\nL\u1ecbch s\u1eed ph\u00e1t tri\u1ec3n<\/strong><\/h3>\nTr\u01b0\u1edbc khi Einstein \u0111\u01b0a ra nh\u1eefng l\u00fd thuy\u1ebft mang t\u00ednh c\u00e1ch m\u1ea1ng n\u00e0y, nh\u00e0 v\u1eadt l\u00fd James Clerk Maxwell \u0111\u00e3 \u0111\u1eb7t n\u1ec1n m\u00f3ng quan tr\u1ecdng t\u1eeb n\u0103m 1865. Th\u00f4ng qua h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh Maxwell n\u1ed5i ti\u1ebfng, \u00f4ng \u0111\u00e3 ch\u1ee9ng minh r\u1eb1ng s\u00f3ng \u0111i\u1ec7n t\u1eeb lan truy\u1ec1n trong kh\u00f4ng gian v\u1edbi t\u1ed1c \u0111\u1ed9 c\u1ed1 \u0111\u1ecbnh v\u00e0 d\u1ef1 \u0111o\u00e1n r\u1eb1ng \u00e1nh s\u00e1ng ch\u00ednh l\u00e0 m\u1ed9t d\u1ea1ng s\u00f3ng \u0111i\u1ec7n t\u1eeb. H\u1eb1ng s\u1ed1 c t\u1eeb \u0111\u00f3 tr\u1edf th\u00e0nh c\u1ea7u n\u1ed1i th\u1ed1ng nh\u1ea5t gi\u1eefa \u0111i\u1ec7n t\u1eeb h\u1ecdc, quang h\u1ecdc v\u00e0 sau n\u00e0y l\u00e0 c\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed, \u0111\u00f3ng vai tr\u00f2 l\u00e0 “t\u1ed1c \u0111\u1ed9 c\u1ee7a nh\u00e2n qu\u1ea3” trong c\u1ea5u tr\u00fac kh\u00f4ng-th\u1eddi gian.<\/span><\/p>\n\n- Gi\u00e1 tr\u1ecb ch\u00ednh x\u00e1c:<\/b> 299.792.458 m\/s (kh\u00f4ng c\u00f3 sai s\u1ed1 \u0111o l\u01b0\u1eddng do \u0111\u1ecbnh ngh\u0129a m\u00e9t d\u1ef1a tr\u00ean gi\u00e2y).<\/span><\/li>\n
- K\u00fd hi\u1ec7u:<\/b> “c” (vi\u1ebft t\u1eaft c\u1ee7a t\u1eeb “celeritas” trong ti\u1ebfng Latinh, ngh\u0129a l\u00e0 t\u1ed1c \u0111\u1ed9).<\/span><\/li>\n
- Vai tr\u00f2:<\/b> Gi\u1edbi h\u1ea1n t\u1ed1c \u0111\u1ed9 truy\u1ec1n th\u00f4ng tin v\u00e0 v\u1eadt ch\u1ea5t trong v\u0169 tr\u1ee5.<\/span><\/li>\n
- L\u00fd thuy\u1ebft li\u00ean quan:<\/b> Thuy\u1ebft \u0111i\u1ec7n t\u1eeb c\u1ee7a Maxwell v\u00e0 Thuy\u1ebft t\u01b0\u01a1ng \u0111\u1ed1i h\u1eb9p c\u1ee7a Einstein.<\/span><\/li>\n<\/ul>\n
![\"toc-do-anh-sang-1\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-1.jpg\")
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Vi\u1ec7c hi\u1ec3u r\u00f5 b\u1ea3n ch\u1ea5t c\u1ee7a h\u1eb1ng s\u1ed1 c gi\u00fap ch\u00fang ta gi\u1ea3i m\u00e3 \u0111\u01b0\u1ee3c c\u1ea5u tr\u00fac c\u1ee7a v\u0169 tr\u1ee5, t\u1eeb nh\u1eefng h\u1ea1t h\u1ea1 nguy\u00ean t\u1eed nh\u1ecf b\u00e9 nh\u1ea5t cho \u0111\u1ebfn s\u1ef1 gi\u00e3n n\u1edf c\u1ee7a c\u00e1c thi\u00ean h\u00e0 xa x\u00f4i. N\u00f3 kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t con s\u1ed1 kh\u00f4 khan m\u00e0 l\u00e0 ch\u00eca kh\u00f3a \u0111\u1ec3 m\u1edf ra c\u00e1nh c\u1eeda hi\u1ec3u bi\u1ebft v\u1ec1 kh\u00f4ng gian, th\u1eddi gian v\u00e0 n\u0103ng l\u01b0\u1ee3ng.<\/span><\/p>\nL\u1ecbch S\u1eed \u0110o L\u01b0\u1eddng T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng<\/b><\/h2>\n
Trong su\u1ed1t nhi\u1ec1u th\u1ebf k\u1ef7, nh\u00e2n lo\u1ea1i \u0111\u00e3 t\u1eebng tin r\u1eb1ng \u00e1nh s\u00e1ng lan truy\u1ec1n t\u1ee9c th\u1eddi, t\u1ee9c l\u00e0 t\u1ed1c \u0111\u1ed9 c\u1ee7a n\u00f3 l\u00e0 v\u00f4 h\u1ea1n. Ph\u1ea3i \u0111\u1ebfn th\u1ebf k\u1ef7 17, c\u00e1c nh\u00e0 khoa h\u1ecdc m\u1edbi b\u1eaft \u0111\u1ea7u t\u00ecm ki\u1ebfm b\u1eb1ng ch\u1ee9ng th\u1ef1c nghi\u1ec7m \u0111\u1ec3 ch\u1ee9ng minh r\u1eb1ng <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> l\u00e0 h\u1eefu h\u1ea1n. <\/span><\/p>\nTh\u1ebf k\u1ef7 17<\/strong><\/h3>\nNg\u01b0\u1eddi ti\u00ean phong trong l\u0129nh v\u1ef1c n\u00e0y l\u00e0 nh\u00e0 thi\u00ean v\u0103n h\u1ecdc ng\u01b0\u1eddi \u0110an M\u1ea1ch Ole R\u00f8mer. <\/span>V\u00e0o n\u0103m 1676, th\u00f4ng qua vi\u1ec7c quan s\u00e1t t\u1ec9 m\u1ec9 c\u00e1c v\u1ec7 tinh c\u1ee7a Sao M\u1ed9c, \u0111\u1eb7c bi\u1ec7t l\u00e0 m\u1eb7t tr\u0103ng Io, R\u00f8mer \u0111\u00e3 nh\u1eadn th\u1ea5y s\u1ef1 sai l\u1ec7ch v\u1ec1 th\u1eddi gian trong c\u00e1c l\u1ea7n nguy\u1ec7t th\u1ef1c c\u1ee7a Io t\u00f9y thu\u1ed9c v\u00e0o kho\u1ea3ng c\u00e1ch gi\u1eefa Tr\u00e1i \u0110\u1ea5t v\u00e0 Sao M\u1ed9c.<\/span><\/p>\n![\"toc-do-anh-sang-2\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-2.jpg\")
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D\u1ef1a tr\u00ean nh\u1eefng d\u1eef li\u1ec7u quan s\u00e1t thi\u00ean v\u0103n n\u00e0y, R\u00f8mer \u0111\u00e3 \u0111\u01b0a ra \u01b0\u1edbc t\u00ednh \u0111\u1ea7u ti\u00ean v\u1ec1 t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng, kho\u1ea3ng 227.000 km\/s. M\u1eb7c d\u00f9 con s\u1ed1 n\u00e0y th\u1ea5p h\u01a1n kho\u1ea3ng 26% so v\u1edbi gi\u00e1 tr\u1ecb th\u1ef1c t\u1ebf ng\u00e0y nay, nh\u01b0ng \u0111\u00e2y l\u00e0 m\u1ed9t b\u01b0\u1edbc ngo\u1eb7t l\u1ecbch s\u1eed v\u0129 \u0111\u1ea1i, b\u00e1c b\u1ecf quan ni\u1ec7m ng\u00e0n n\u0103m v\u1ec1 s\u1ef1 truy\u1ec1n \u00e1nh s\u00e1ng t\u1ee9c th\u1eddi. Sau R\u00f8mer, nhi\u1ec1u nh\u00e0 khoa h\u1ecdc kh\u00e1c nh\u01b0 Hippolyte Fizeau v\u00e0 L\u00e9on Foucault \u0111\u00e3 ph\u00e1t tri\u1ec3n c\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u0111o \u0111\u1ea1c tr\u00ean m\u1eb7t \u0111\u1ea5t s\u1eed d\u1ee5ng b\u00e1nh xe r\u0103ng c\u01b0a quay v\u00e0 g\u01b0\u01a1ng quay, gi\u00fap tinh ch\u1ec9nh con s\u1ed1 n\u00e0y v\u1edbi \u0111\u1ed9 ch\u00ednh x\u00e1c ng\u00e0y c\u00e0ng cao h\u01a1n qua t\u1eebng th\u1ebf k\u1ef7.<\/span><\/p>\nTh\u1ebf k\u1ef7 20<\/strong><\/h3>\n\u0110\u1ebfn th\u1ebf k\u1ef7 20, v\u1edbi s\u1ef1 ra \u0111\u1eddi c\u1ee7a c\u00f4ng ngh\u1ec7 laser v\u00e0 \u0111\u1ed3ng h\u1ed3 nguy\u00ean t\u1eed cesium c\u00f3 \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ef1c cao, vi\u1ec7c \u0111o \u0111\u1ea1c <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> \u0111\u00e3 \u0111\u1ea1t \u0111\u1ebfn gi\u1edbi h\u1ea1n c\u1ee7a sai s\u1ed1 th\u1ef1c nghi\u1ec7m. V\u00e0o n\u0103m 1983, t\u1ea1i H\u1ed9i ngh\u1ecb To\u00e0n th\u1ec3 v\u1ec1 C\u00e2n \u0111o (CGPM), c\u1ed9ng \u0111\u1ed3ng khoa h\u1ecdc qu\u1ed1c t\u1ebf \u0111\u00e3 \u0111i \u0111\u1ebfn m\u1ed9t quy\u1ebft \u0111\u1ecbnh mang t\u00ednh l\u1ecbch s\u1eed. Thay v\u00ec c\u1ed1 g\u1eafng \u0111o t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng ng\u00e0y c\u00e0ng ch\u00ednh x\u00e1c h\u01a1n, h\u1ecd \u0111\u00e3 \u0111\u1ecbnh ngh\u0129a l\u1ea1i \u0111\u01a1n v\u1ecb “m\u00e9t” d\u1ef1a tr\u00ean h\u1eb1ng s\u1ed1 c. Theo \u0111\u00f3, 1 m\u00e9t l\u00e0 qu\u00e3ng \u0111\u01b0\u1eddng \u00e1nh s\u00e1ng \u0111i \u0111\u01b0\u1ee3c trong ch\u00e2n kh\u00f4ng trong kho\u1ea3ng th\u1eddi gian 1\/299.792.458 gi\u00e2y.<\/span><\/p>\n\n- N\u0103m 1676:<\/b> Ole R\u00f8mer \u01b0\u1edbc t\u00ednh c ~ 227.000 km\/s qua quan s\u00e1t v\u1ec7 tinh Io c\u1ee7a Sao M\u1ed9c.<\/span><\/li>\n
- N\u0103m 1729:<\/b> James Bradley s\u1eed d\u1ee5ng hi\u1ec7n t\u01b0\u1ee3ng tinh sai \u00e1nh s\u00e1ng \u0111\u1ec3 x\u00e1c nh\u1eadn c h\u1eefu h\u1ea1n.<\/span><\/li>\n
- N\u0103m 1849:<\/b> Hippolyte Fizeau d\u00f9ng b\u00e1nh xe r\u0103ng c\u01b0a, \u0111o \u0111\u01b0\u1ee3c c ~ 313.300 km\/s.<\/span><\/li>\n
- N\u0103m 1983:<\/b> \u0110\u1ecbnh ngh\u0129a chu\u1ea9n qu\u1ed1c t\u1ebf: c = 299.792.458 m\/s, d\u00f9ng l\u00e0m c\u01a1 s\u1edf \u0111\u1ecbnh ngh\u0129a m\u00e9t.<\/span><\/li>\n<\/ul>\n
![\"toc-do-anh-sang-3\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-3.jpg\")
<\/p>\n
Quy\u1ebft \u0111\u1ecbnh n\u0103m 1983 \u0111\u00e3 bi\u1ebfn t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng t\u1eeb m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng c\u1ea7n \u0111o \u0111\u1ea1c th\u00e0nh m\u1ed9t h\u1eb1ng s\u1ed1 \u0111\u1ecbnh ngh\u0129a tuy\u1ec7t \u0111\u1ed1i. \u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 gi\u00e1 tr\u1ecb c\u1ee7a c s\u1ebd kh\u00f4ng bao gi\u1edd thay \u0111\u1ed5i n\u1eefa trong h\u1ec7 th\u1ed1ng \u0111o l\u01b0\u1eddng c\u1ee7a ch\u00fang ta, v\u00e0 b\u1ea5t k\u1ef3 s\u1ef1 c\u1ea3i ti\u1ebfn n\u00e0o trong c\u00f4ng ngh\u1ec7 \u0111o l\u01b0\u1eddng s\u1ebd ch\u1ec9 l\u00e0m thay \u0111\u1ed5i \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a \u0111\u1ecbnh ngh\u0129a v\u1ec1 \u0111\u1ed9 d\u00e0i m\u00e9t m\u00e0 th\u00f4i.<\/span><\/p>\nT\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng Trong C\u00e1c M\u00f4i Tr\u01b0\u1eddng Kh\u00e1c<\/b><\/h2>\n
Khi nh\u1eafc \u0111\u1ebfn con s\u1ed1 x\u1ea5p x\u1ec9 300.000 km\/s, ch\u00fang ta \u0111ang n\u00f3i \u0111\u1ebfn <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> t\u1ed1i \u0111a trong m\u00f4i tr\u01b0\u1eddng ch\u00e2n kh\u00f4ng ho\u00e0n h\u1ea3o. Tuy nhi\u00ean, trong th\u1ef1c t\u1ebf, \u00e1nh s\u00e1ng th\u01b0\u1eddng xuy\u00ean ph\u1ea3i di chuy\u1ec3n qua c\u00e1c m\u00f4i tr\u01b0\u1eddng v\u1eadt ch\u1ea5t nh\u01b0 kh\u00f4ng kh\u00ed, n\u01b0\u1edbc, th\u1ee7y tinh hay kim c\u01b0\u01a1ng. Khi \u0111i qua c\u00e1c m\u00f4i tr\u01b0\u1eddng n\u00e0y, t\u1ed1c \u0111\u1ed9 c\u1ee7a \u00e1nh s\u00e1ng s\u1ebd b\u1ecb gi\u1ea3m \u0111i do s\u1ef1 t\u01b0\u01a1ng t\u00e1c \u0111i\u1ec7n t\u1eeb gi\u1eefa c\u00e1c photon \u00e1nh s\u00e1ng v\u00e0 c\u00e1c h\u1ea1t mang \u0111i\u1ec7n (electron) trong c\u1ea5u tr\u00fac nguy\u00ean t\u1eed c\u1ee7a v\u1eadt li\u1ec7u. T\u1ef7 l\u1ec7 gi\u1eefa t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong ch\u00e2n kh\u00f4ng (c) v\u00e0 t\u1ed1c \u0111\u1ed9 trong m\u00f4i tr\u01b0\u1eddng (v) \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 chi\u1ebft su\u1ea5t (n), v\u1edbi c\u00f4ng th\u1ee9c n = c\/v.<\/span><\/p>\n\n- Ch\u00e2n kh\u00f4ng (n=1):<\/b> 299.792.458 m\/s (T\u1ed1c \u0111\u1ed9 t\u1ed1i \u0111a tuy\u1ec7t \u0111\u1ed1i).<\/span><\/li>\n
- Kh\u00f4ng kh\u00ed (n\u22481.0003):<\/b> ~299.702.547 m\/s (Ch\u1eadm h\u01a1n ch\u00e2n kh\u00f4ng r\u1ea5t \u00edt).<\/span><\/li>\n
- N\u01b0\u1edbc (n\u22481.33):<\/b> ~225.000 km\/s (Gi\u1ea3m kho\u1ea3ng 25% so v\u1edbi c).<\/span><\/li>\n
- Th\u1ee7y tinh (n\u22481.5):<\/b> ~200.000 km\/s (T\u00f9y thu\u1ed9c v\u00e0o lo\u1ea1i th\u1ee7y tinh).<\/span><\/li>\n
- Kim c\u01b0\u01a1ng (n\u22482.42):<\/b> ~124.000 km\/s (Gi\u1ea3m h\u01a1n 50% so v\u1edbi c, g\u00e2y t\u00e1n s\u1eafc m\u1ea1nh).<\/span><\/li>\n<\/ul>\n
![\"toc-do-anh-sang-4\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-4.jpg\")
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Hi\u1ec3u bi\u1ebft v\u1ec1 t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong c\u00e1c m\u00f4i tr\u01b0\u1eddng kh\u00e1c nhau l\u00e0 c\u01a1 s\u1edf \u0111\u1ec3 ch\u1ebf t\u1ea1o c\u00e1c thi\u1ebft b\u1ecb quang h\u1ecdc nh\u01b0 k\u00ednh m\u1eaft, \u1ed1ng k\u00ednh m\u00e1y \u1ea3nh, k\u00ednh hi\u1ec3n vi v\u00e0 \u0111\u1eb7c bi\u1ec7t l\u00e0 c\u00f4ng ngh\u1ec7 s\u1ee3i quang, n\u01a1i \u00e1nh s\u00e1ng \u0111\u01b0\u1ee3c d\u1eabn truy\u1ec1n b\u00ean trong l\u00f5i th\u1ee7y tinh \u0111\u1ec3 truy\u1ec1n t\u1ea3i d\u1eef li\u1ec7u Internet \u0111i kh\u1eafp th\u1ebf gi\u1edbi.<\/span><\/p>\nT\u1ea1i Sao T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng Quan Tr\u1ecdng Trong V\u1eadt L\u00fd?<\/b><\/h2>\n
T\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t con s\u1ed1 \u0111o v\u1eadn t\u1ed1c di chuy\u1ec3n, m\u00e0 n\u00f3 l\u00e0 h\u1eb1ng s\u1ed1 c\u1ea5u tr\u00fac c\u1ee7a v\u0169 tr\u1ee5, \u0111\u00f3ng vai tr\u00f2 then ch\u1ed1t trong nhi\u1ec1u l\u0129nh v\u1ef1c v\u1eadt l\u00fd t\u1eeb vi m\u00f4 \u0111\u1ebfn v\u0129 m\u00f4. T\u1ea7m quan tr\u1ecdng n\u1ed5i ti\u1ebfng nh\u1ea5t c\u1ee7a c n\u1eb1m trong ph\u01b0\u01a1ng tr\u00ecnh huy\u1ec1n tho\u1ea1i E=mc\u00b2 c\u1ee7a Albert Einstein, n\u01a1i <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> \u0111\u00f3ng vai tr\u00f2 trung t\u00e2m. Ph\u01b0\u01a1ng tr\u00ecnh n\u00e0y cho th\u1ea5y n\u0103ng l\u01b0\u1ee3ng (E) v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng (m) l\u00e0 hai m\u1eb7t c\u1ee7a c\u00f9ng m\u1ed9t \u0111\u1ed3ng xu, v\u00e0 ch\u00fang c\u00f3 th\u1ec3 chuy\u1ec3n h\u00f3a cho nhau th\u00f4ng qua b\u00ecnh ph\u01b0\u01a1ng t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng. V\u00ec c l\u00e0 m\u1ed9t con s\u1ed1 r\u1ea5t l\u1edbn, n\u00ean m\u1ed9t l\u01b0\u1ee3ng kh\u1ed1i l\u01b0\u1ee3ng c\u1ef1c nh\u1ecf c\u0169ng ch\u1ee9a \u0111\u1ef1ng m\u1ed9t ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng kh\u1ed5ng l\u1ed3.<\/span><\/p>\n\n- Ph\u01b0\u01a1ng tr\u00ecnh E=mc\u00b2:<\/b> Quy \u0111\u1ecbnh m\u1ed1i quan h\u1ec7 m\u1eadt thi\u1ebft gi\u1eefa n\u0103ng l\u01b0\u1ee3ng v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng.<\/span><\/li>\n
- H\u1ec7 th\u1ed1ng \u0111\u1ecbnh v\u1ecb GPS:<\/b> Y\u00eau c\u1ea7u hi\u1ec7u ch\u1ec9nh th\u1eddi gian d\u1ef1a tr\u00ean thuy\u1ebft t\u01b0\u01a1ng \u0111\u1ed1i v\u00e0 t\u1ed1c \u0111\u1ed9 c \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o \u0111\u1ed9 ch\u00ednh x\u00e1c.<\/span><\/li>\n
- \u0110o \u0111\u1ea1c v\u0169 tr\u1ee5:<\/b> S\u1eed d\u1ee5ng “n\u0103m \u00e1nh s\u00e1ng” (9,46 ngh\u00ecn t\u1ef7 km) l\u00e0m \u0111\u01a1n v\u1ecb \u0111o kho\u1ea3ng c\u00e1ch li\u00ean sao.<\/span><\/li>\n
- T\u00ednh nh\u00e2n qu\u1ea3:<\/b> c \u0111\u1ea3m b\u1ea3o nguy\u00ean nh\u00e2n lu\u00f4n x\u1ea3y ra tr\u01b0\u1edbc k\u1ebft qu\u1ea3 trong m\u1ecdi h\u1ec7 quy chi\u1ebfu qu\u00e1n t\u00ednh.<\/span><\/li>\n<\/ul>\n
![\"toc-do-anh-sang-5\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-5.jpg\")
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Nh\u01b0 v\u1eady, h\u1eb1ng s\u1ed1 c l\u00e0 s\u1ee3i d\u00e2y li\u00ean k\u1ebft m\u1ecdi hi\u1ec7n t\u01b0\u1ee3ng v\u1eadt l\u00fd, t\u1eeb n\u0103ng l\u01b0\u1ee3ng c\u1ee7a m\u1ed9t nguy\u00ean t\u1eed nh\u1ecf b\u00e9 \u0111\u1ebfn c\u1ea5u tr\u00fac kh\u00f4ng-th\u1eddi gian c\u1ee7a to\u00e0n b\u1ed9 v\u0169 tr\u1ee5 bao la.<\/span><\/p>\nTrong V\u0169 Tr\u1ee5 C\u00f3 Th\u1ee9 G\u00ec Nhanh H\u01a1n \u00c1nh S\u00e1ng Kh\u00f4ng?<\/b><\/h2>\n
Theo Thuy\u1ebft t\u01b0\u01a1ng \u0111\u1ed1i h\u1eb9p, <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> trong ch\u00e2n kh\u00f4ng l\u00e0 gi\u1edbi h\u1ea1n t\u1ed1c \u0111\u1ed9 nghi\u00eam ng\u1eb7t \u0111\u1ed1i v\u1edbi b\u1ea5t k\u1ef3 v\u1eadt ch\u1ea5t n\u00e0o mang th\u00f4ng tin ho\u1eb7c n\u0103ng l\u01b0\u1ee3ng. Tuy nhi\u00ean, c\u00e2u h\u1ecfi “c\u00f3 g\u00ec nhanh h\u01a1n \u00e1nh s\u00e1ng kh\u00f4ng” lu\u00f4n l\u00e0 \u0111\u1ec1 t\u00e0i h\u1ea5p d\u1eabn v\u00e0 g\u00e2y nhi\u1ec1u tranh c\u00e3i. Trong th\u1ef1c t\u1ebf, c\u00f3 m\u1ed9t s\u1ed1 hi\u1ec7n t\u01b0\u1ee3ng v\u1eadt l\u00fd d\u01b0\u1eddng nh\u01b0 vi ph\u1ea1m quy t\u1eafc n\u00e0y, nh\u01b0ng khi xem x\u00e9t k\u1ef9 l\u01b0\u1ee1ng, ch\u00fang kh\u00f4ng h\u1ec1 m\u00e2u thu\u1eabn v\u1edbi nguy\u00ean l\u00fd c\u1ee7a Einstein.<\/span><\/p>\nTr\u01b0\u1eddng h\u1ee3p ph\u1ed5 bi\u1ebfn nh\u1ea5t th\u01b0\u1eddng \u0111\u01b0\u1ee3c nh\u1eafc \u0111\u1ebfn l\u00e0 s\u1ef1 gi\u00e3n n\u1edf c\u1ee7a v\u0169 tr\u1ee5. C\u00e1c thi\u00ean h\u00e0 \u1edf r\u1ea5t xa Tr\u00e1i \u0110\u1ea5t \u0111ang r\u1eddi xa ch\u00fang ta v\u1edbi t\u1ed1c \u0111\u1ed9 nhanh h\u01a1n \u00e1nh s\u00e1ng. Tuy nhi\u00ean, \u0111i\u1ec1u n\u00e0y kh\u00f4ng ph\u1ea3i do c\u00e1c thi\u00ean h\u00e0 t\u1ef1 di chuy\u1ec3n trong kh\u00f4ng gian nhanh h\u01a1n c, m\u00e0 l\u00e0 do ch\u00ednh kh\u00f4ng gian gi\u1eefa c\u00e1c thi\u00ean h\u00e0 \u0111ang gi\u00e3n n\u1edf.\u00a0<\/span><\/p>\n\n- S\u1ef1 gi\u00e3n n\u1edf v\u0169 tr\u1ee5:<\/b> Kh\u00f4ng gian c\u00f3 th\u1ec3 gi\u00e3n n\u1edf nhanh h\u01a1n c, khi\u1ebfn c\u00e1c thi\u00ean h\u00e0 xa r\u1eddi nhau v\u1edbi t\u1ed1c \u0111\u1ed9 bi\u1ec3u ki\u1ebfn > c.<\/span><\/li>\n
- S\u1ef1 ki\u1ec7n Neutrino (2011):<\/b> M\u1ed9t sai l\u1ea7m th\u1ef1c nghi\u1ec7m n\u1ed5i ti\u1ebfng do l\u1ed7i k\u1ef9 thu\u1eadt, sau \u0111\u00f3 \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u00ednh ch\u00ednh l\u00e0 tu\u00e2n th\u1ee7 c.<\/span><\/li>\n
- Hi\u1ec7n t\u01b0\u1ee3ng v\u01b0\u1edbng v\u00edu l\u01b0\u1ee3ng t\u1eed:<\/b> Hai h\u1ea1t t\u01b0\u01a1ng t\u00e1c t\u1ee9c th\u1eddi b\u1ea5t k\u1ec3 kho\u1ea3ng c\u00e1ch, nh\u01b0ng kh\u00f4ng th\u1ec3 d\u00f9ng \u0111\u1ec3 truy\u1ec1n tin nhanh h\u01a1n c.<\/span><\/li>\n
- Tia Plasma t\u1eeb l\u1ed7 \u0111en:<\/b> N\u0103m 2020, quan s\u00e1t tia plasma t\u1eeb m\u1ed9t quasar \u0111\u1ea1t 94% c, l\u00e0 v\u1eadt ch\u1ea5t th\u1ef1c t\u1ebf g\u1ea7n c nh\u1ea5t t\u1eebng ghi nh\u1eadn.<\/span><\/li>\n<\/ul>\n
![\"toc-do-anh-sang-6\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-6.jpg\")
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Ngo\u00e0i ra, trong m\u00f4i tr\u01b0\u1eddng v\u1eadt ch\u1ea5t (nh\u01b0 n\u01b0\u1edbc), c\u00e1c h\u1ea1t c\u00f3 th\u1ec3 di chuy\u1ec3n nhanh h\u01a1n \u00e1nh s\u00e1ng *trong m\u00f4i tr\u01b0\u1eddng \u0111\u00f3* (nh\u01b0ng v\u1eabn ch\u1eadm h\u01a1n c trong ch\u00e2n kh\u00f4ng).\u00a0<\/span><\/p>\n\u1ee8ng D\u1ee5ng Th\u1ef1c T\u1ebf C\u1ee7a T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng<\/b><\/h2>\n
M\u1eb7c d\u00f9 <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> l\u00e0 m\u1ed9t h\u1eb1ng s\u1ed1 v\u1eadt l\u00fd c\u00f3 v\u1ebb tr\u1eebu t\u01b0\u1ee3ng, nh\u01b0ng n\u00f3 l\u1ea1i l\u00e0 n\u1ec1n t\u1ea3ng cho v\u00f4 s\u1ed1 c\u00f4ng ngh\u1ec7 hi\u1ec7n \u0111\u1ea1i m\u00e0 ch\u00fang ta s\u1eed d\u1ee5ng h\u00e0ng ng\u00e0y. \u1ee8ng d\u1ee5ng ph\u1ed5 bi\u1ebfn v\u00e0 quan tr\u1ecdng nh\u1ea5t ch\u00ednh l\u00e0 c\u00f4ng ngh\u1ec7 c\u00e1p quang. Internet to\u00e0n c\u1ea7u ho\u1ea1t \u0111\u1ed9ng d\u1ef1a tr\u00ean vi\u1ec7c truy\u1ec1n t\u1ea3i c\u00e1c xung \u00e1nh s\u00e1ng mang d\u1eef li\u1ec7u \u0111i qua c\u00e1c s\u1ee3i th\u1ee7y tinh m\u1ecfng v\u1edbi t\u1ed1c \u0111\u1ed9 \u0111\u1ea1t kho\u1ea3ng 200.000 km\/s (t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong th\u1ee7y tinh). Nh\u1edd t\u1ed1c \u0111\u1ed9 c\u1ef1c cao n\u00e0y, ch\u00fang ta c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n c\u00e1c cu\u1ed9c g\u1ecdi video th\u1eddi gian th\u1ef1c, giao d\u1ecbch t\u00e0i ch\u00ednh qu\u1ed1c t\u1ebf v\u00e0 truy c\u1eadp th\u00f4ng tin t\u1eeb n\u1eeda kia b\u00e1n c\u1ea7u ch\u1ec9 trong t\u00edch t\u1eafc.<\/span><\/p>\n![\"toc-do-anh-sang-7\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-7.jpg\")
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C\u00f4ng ngh\u1ec7 Laser c\u0169ng l\u00e0 m\u1ed9t \u1ee9ng d\u1ee5ng tr\u1ef1c ti\u1ebfp kh\u00e1c. T\u1eeb c\u00e1c \u0111\u1ea7u \u0111\u1ecdc m\u00e3 v\u1ea1ch trong si\u00eau th\u1ecb, ph\u1eabu thu\u1eadt m\u1eaft LASIK trong y t\u1ebf, cho \u0111\u1ebfn c\u00e1c m\u00e1y c\u1eaft kim lo\u1ea1i ch\u00ednh x\u00e1c trong c\u00f4ng nghi\u1ec7p, t\u1ea5t c\u1ea3 \u0111\u1ec1u d\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t v\u00e0 t\u1ed1c \u0111\u1ed9 c\u1ee7a ch\u00f9m tia s\u00e1ng t\u1eadp trung. Trong l\u0129nh v\u1ef1c \u0111o \u0111\u1ea1c, c\u00e1c thi\u1ebft b\u1ecb \u0111o kho\u1ea3ng c\u00e1ch b\u1eb1ng laser (LiDAR) \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i trong x\u00e2y d\u1ef1ng, tr\u1eafc \u0111\u1ecba v\u00e0 \u0111\u1eb7c bi\u1ec7t l\u00e0 trong c\u00f4ng ngh\u1ec7 xe t\u1ef1 l\u00e1i \u0111\u1ec3 l\u1eadp b\u1ea3n \u0111\u1ed3 m\u00f4i tr\u01b0\u1eddng xung quanh xe v\u1edbi t\u1ed1c \u0111\u1ed9 ph\u1ea3n h\u1ed3i t\u1ee9c th\u00ec.<\/span><\/p>\nTrong nghi\u00ean c\u1ee9u khoa h\u1ecdc, t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng cho ph\u00e9p c\u00e1c nh\u00e0 thi\u00ean v\u0103n h\u1ecdc nh\u00ecn ng\u01b0\u1ee3c v\u1ec1 qu\u00e1 kh\u1ee9. K\u00ednh vi\u1ec5n v\u1ecdng kh\u00f4ng gian Hubble v\u00e0 g\u1ea7n \u0111\u00e2y l\u00e0 James Webb ho\u1ea1t \u0111\u1ed9ng nh\u01b0 nh\u1eefng c\u1ed7 m\u00e1y th\u1eddi gian, thu nh\u1eadn \u00e1nh s\u00e1ng t\u1eeb c\u00e1c thi\u00ean h\u00e0 xa x\u00f4i nh\u01b0 GN-z11 (c\u00e1ch ch\u00fang ta 13,4 t\u1ef7 n\u0103m \u00e1nh s\u00e1ng).\u00a0<\/span><\/p>\nC\u00e2u H\u1ecfi Th\u01b0\u1eddng G\u1eb7p V\u1ec1 T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng (FAQ)<\/b><\/h2>\n
Ch\u1ee7 \u0111\u1ec1 v\u1ec1 <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> lu\u00f4n g\u1ee3i m\u1edf s\u1ef1 t\u00f2 m\u00f2 v\u00e0 \u0111i k\u00e8m v\u1edbi nhi\u1ec1u th\u1eafc m\u1eafc th\u00fa v\u1ecb. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 gi\u1ea3i \u0111\u00e1p cho nh\u1eefng c\u00e2u h\u1ecfi ph\u1ed5 bi\u1ebfn nh\u1ea5t m\u00e0 m\u1ecdi ng\u01b0\u1eddi th\u01b0\u1eddng \u0111\u1eb7t ra khi t\u00ecm hi\u1ec3u v\u1ec1 h\u1eb1ng s\u1ed1 v\u1eadt l\u00fd \u0111\u1eb7c bi\u1ec7t n\u00e0y, gi\u00fap quy \u0111\u1ed5i c\u00e1c con s\u1ed1 kh\u1ed5ng l\u1ed3 v\u1ec1 c\u00e1c \u0111\u01a1n v\u1ecb quen thu\u1ed9c h\u01a1n.<\/span><\/p>\nT\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng b\u1eb1ng bao nhi\u00eau km\/h? <\/b>X\u1ea5p x\u1ec9 <\/span>1.079.252.848 km\/h<\/b>. M\u1ed9t con s\u1ed1 kh\u1ed5ng l\u1ed3 v\u01b0\u1ee3t xa m\u1ecdi ph\u01b0\u01a1ng ti\u1ec7n nh\u00e2n t\u1ea1o.<\/span><\/p>\n1 gi\u00e2y \u00e1nh s\u00e1ng b\u1eb1ng bao nhi\u00eau km? <\/b>Trong 1 gi\u00e2y, \u00e1nh s\u00e1ng \u0111i \u0111\u01b0\u1ee3c <\/span>299.792 km<\/b>, \u0111\u1ee7 \u0111\u1ec3 quay quanh Tr\u00e1i \u0110\u1ea5t h\u01a1n 7,5 v\u00f2ng.<\/span><\/p>\nT\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng so v\u1edbi \u00e2m thanh? <\/b>\u00c1nh s\u00e1ng (trong ch\u00e2n kh\u00f4ng) nhanh g\u1ea5p kho\u1ea3ng <\/span>874.030 l\u1ea7n<\/b> so v\u1edbi \u00e2m thanh (trong kh\u00f4ng kh\u00ed).<\/span><\/p>\n![\"toc-do-anh-sang-8\"](\"https:\/\/hoanghamobile.com\/tin-tuc\/wp-content\/uploads\/2026\/02\/toc-do-anh-sang-8.jpg\")
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M\u1ea5t bao l\u00e2u \u0111\u1ec3 \u00e1nh s\u00e1ng t\u1eeb M\u1eb7t Tr\u1eddi \u0111\u1ebfn Tr\u00e1i \u0110\u1ea5t? <\/b>Trung b\u00ecnh kho\u1ea3ng <\/span>8 ph\u00fat 20 gi\u00e2y<\/b>. N\u1ebfu M\u1eb7t Tr\u1eddi t\u1eaft ng\u1ea5m ngay b\u00e2y gi\u1edd, h\u01a1n 8 ph\u00fat sau ch\u00fang ta m\u1edbi bi\u1ebft.<\/span><\/p>\nC\u00f3 c\u00e1ch n\u00e0o \u0111i nhanh h\u01a1n \u00e1nh s\u00e1ng (FTL) kh\u00f4ng? <\/b>V\u1ec1 m\u1eb7t v\u1eadt l\u00fd th\u1ef1c nghi\u1ec7m hi\u1ec7n t\u1ea1i l\u00e0 KH\u00d4NG. C\u00e1c kh\u00e1i ni\u1ec7m nh\u01b0 Wormhole hay Warp drive v\u1eabn ch\u1ec9 n\u1eb1m tr\u00ean l\u00fd thuy\u1ebft to\u00e1n h\u1ecdc.<\/span><\/p>\nNh\u1eefng con s\u1ed1 v\u00e0 s\u1ef1 ki\u1ec7n n\u00e0y nh\u1eafc nh\u1edf ch\u00fang ta v\u1ec1 s\u1ef1 gi\u1edbi h\u1ea1n c\u1ee7a con ng\u01b0\u1eddi tr\u01b0\u1edbc s\u1ef1 v\u0129 \u0111\u1ea1i c\u1ee7a c\u00e1c quy lu\u1eadt v\u1eadt l\u00fd, \u0111\u1ed3ng th\u1eddi kh\u01a1i d\u1eady kh\u00e1t v\u1ecdng kh\u00e1m ph\u00e1 nh\u1eefng ch\u00e2n tr\u1eddi m\u1edbi trong khoa h\u1ecdc v\u0169 tr\u1ee5.<\/span><\/p>\nT\u1ea1m k\u1ebft<\/strong><\/h2>\nT\u00f3m l\u1ea1i, vi\u1ec7c t\u00ecm hi\u1ec3u t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng l\u00e0 bao nhi\u00eau km\/s gi\u00fap ch\u00fang ta hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 nh\u1eefng quy lu\u1eadt n\u1ec1n t\u1ea3ng chi ph\u1ed1i v\u0169 tr\u1ee5. V\u1edbi gi\u00e1 tr\u1ecb ch\u00ednh x\u00e1c kho\u1ea3ng 299.792 km\/s, t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng kh\u00f4ng ch\u1ec9 \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong v\u1eadt l\u00fd hi\u1ec7n \u0111\u1ea1i m\u00e0 c\u00f2n l\u00e0 c\u01a1 s\u1edf cho nhi\u1ec1u \u1ee9ng d\u1ee5ng c\u00f4ng ngh\u1ec7 v\u00e0 nghi\u00ean c\u1ee9u thi\u00ean v\u0103n.<\/p>\n
Xem th\u00eam:<\/p>\n
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Kh\u00e1i ni\u1ec7m v\u1ec1 t\u1ed1c \u0111\u1ed9 gi\u1edbi h\u1ea1n n\u00e0y \u0111\u00f3ng vai tr\u00f2 trung t\u00e2m trong n\u1ec1n t\u1ea3ng v\u1eadt l\u00fd l\u00fd thuy\u1ebft, \u0111\u1eb7c bi\u1ec7t l\u00e0 trong Thuy\u1ebft t\u01b0\u01a1ng \u0111\u1ed1i h\u1eb9p do nh\u00e0 v\u1eadt l\u00fd thi\u00ean t\u00e0i Albert Einstein c\u00f4ng b\u1ed1 v\u00e0o n\u0103m 1905. Theo l\u00fd thuy\u1ebft n\u00e0y, kh\u00f4ng m\u1ed9t v\u1eadt th\u1ec3 n\u00e0o c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng ngh\u1ec9 d\u01b0\u01a1ng c\u00f3 th\u1ec3 \u0111\u1ea1t t\u1edbi ho\u1eb7c v\u01b0\u1ee3t qua t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong ch\u00e2n kh\u00f4ng. Khi m\u1ed9t v\u1eadt th\u1ec3 t\u0103ng t\u1ed1c \u0111\u1ed9 \u0111\u1ec3 ti\u1ec7m c\u1eadn v\u1edbi c, kh\u1ed1i l\u01b0\u1ee3ng t\u01b0\u01a1ng \u0111\u1ed1i t\u00ednh c\u1ee7a n\u00f3 s\u1ebd t\u0103ng l\u00ean v\u00f4 h\u1ea1n, \u0111\u00f2i h\u1ecfi m\u1ed9t ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng v\u00f4 t\u1eadn \u0111\u1ec3 ti\u1ebfp t\u1ee5c gia t\u1ed1c, \u0111i\u1ec1u n\u00e0y l\u00e0 b\u1ea5t kh\u1ea3 thi v\u1ec1 m\u1eb7t v\u1eadt l\u00fd.<\/span><\/p>\n Tr\u01b0\u1edbc khi Einstein \u0111\u01b0a ra nh\u1eefng l\u00fd thuy\u1ebft mang t\u00ednh c\u00e1ch m\u1ea1ng n\u00e0y, nh\u00e0 v\u1eadt l\u00fd James Clerk Maxwell \u0111\u00e3 \u0111\u1eb7t n\u1ec1n m\u00f3ng quan tr\u1ecdng t\u1eeb n\u0103m 1865. Th\u00f4ng qua h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh Maxwell n\u1ed5i ti\u1ebfng, \u00f4ng \u0111\u00e3 ch\u1ee9ng minh r\u1eb1ng s\u00f3ng \u0111i\u1ec7n t\u1eeb lan truy\u1ec1n trong kh\u00f4ng gian v\u1edbi t\u1ed1c \u0111\u1ed9 c\u1ed1 \u0111\u1ecbnh v\u00e0 d\u1ef1 \u0111o\u00e1n r\u1eb1ng \u00e1nh s\u00e1ng ch\u00ednh l\u00e0 m\u1ed9t d\u1ea1ng s\u00f3ng \u0111i\u1ec7n t\u1eeb. H\u1eb1ng s\u1ed1 c t\u1eeb \u0111\u00f3 tr\u1edf th\u00e0nh c\u1ea7u n\u1ed1i th\u1ed1ng nh\u1ea5t gi\u1eefa \u0111i\u1ec7n t\u1eeb h\u1ecdc, quang h\u1ecdc v\u00e0 sau n\u00e0y l\u00e0 c\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed, \u0111\u00f3ng vai tr\u00f2 l\u00e0 “t\u1ed1c \u0111\u1ed9 c\u1ee7a nh\u00e2n qu\u1ea3” trong c\u1ea5u tr\u00fac kh\u00f4ng-th\u1eddi gian.<\/span><\/p>\n Vi\u1ec7c hi\u1ec3u r\u00f5 b\u1ea3n ch\u1ea5t c\u1ee7a h\u1eb1ng s\u1ed1 c gi\u00fap ch\u00fang ta gi\u1ea3i m\u00e3 \u0111\u01b0\u1ee3c c\u1ea5u tr\u00fac c\u1ee7a v\u0169 tr\u1ee5, t\u1eeb nh\u1eefng h\u1ea1t h\u1ea1 nguy\u00ean t\u1eed nh\u1ecf b\u00e9 nh\u1ea5t cho \u0111\u1ebfn s\u1ef1 gi\u00e3n n\u1edf c\u1ee7a c\u00e1c thi\u00ean h\u00e0 xa x\u00f4i. N\u00f3 kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t con s\u1ed1 kh\u00f4 khan m\u00e0 l\u00e0 ch\u00eca kh\u00f3a \u0111\u1ec3 m\u1edf ra c\u00e1nh c\u1eeda hi\u1ec3u bi\u1ebft v\u1ec1 kh\u00f4ng gian, th\u1eddi gian v\u00e0 n\u0103ng l\u01b0\u1ee3ng.<\/span><\/p>\n Trong su\u1ed1t nhi\u1ec1u th\u1ebf k\u1ef7, nh\u00e2n lo\u1ea1i \u0111\u00e3 t\u1eebng tin r\u1eb1ng \u00e1nh s\u00e1ng lan truy\u1ec1n t\u1ee9c th\u1eddi, t\u1ee9c l\u00e0 t\u1ed1c \u0111\u1ed9 c\u1ee7a n\u00f3 l\u00e0 v\u00f4 h\u1ea1n. Ph\u1ea3i \u0111\u1ebfn th\u1ebf k\u1ef7 17, c\u00e1c nh\u00e0 khoa h\u1ecdc m\u1edbi b\u1eaft \u0111\u1ea7u t\u00ecm ki\u1ebfm b\u1eb1ng ch\u1ee9ng th\u1ef1c nghi\u1ec7m \u0111\u1ec3 ch\u1ee9ng minh r\u1eb1ng <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> l\u00e0 h\u1eefu h\u1ea1n. <\/span><\/p>\n Ng\u01b0\u1eddi ti\u00ean phong trong l\u0129nh v\u1ef1c n\u00e0y l\u00e0 nh\u00e0 thi\u00ean v\u0103n h\u1ecdc ng\u01b0\u1eddi \u0110an M\u1ea1ch Ole R\u00f8mer. <\/span>V\u00e0o n\u0103m 1676, th\u00f4ng qua vi\u1ec7c quan s\u00e1t t\u1ec9 m\u1ec9 c\u00e1c v\u1ec7 tinh c\u1ee7a Sao M\u1ed9c, \u0111\u1eb7c bi\u1ec7t l\u00e0 m\u1eb7t tr\u0103ng Io, R\u00f8mer \u0111\u00e3 nh\u1eadn th\u1ea5y s\u1ef1 sai l\u1ec7ch v\u1ec1 th\u1eddi gian trong c\u00e1c l\u1ea7n nguy\u1ec7t th\u1ef1c c\u1ee7a Io t\u00f9y thu\u1ed9c v\u00e0o kho\u1ea3ng c\u00e1ch gi\u1eefa Tr\u00e1i \u0110\u1ea5t v\u00e0 Sao M\u1ed9c.<\/span><\/p>\n D\u1ef1a tr\u00ean nh\u1eefng d\u1eef li\u1ec7u quan s\u00e1t thi\u00ean v\u0103n n\u00e0y, R\u00f8mer \u0111\u00e3 \u0111\u01b0a ra \u01b0\u1edbc t\u00ednh \u0111\u1ea7u ti\u00ean v\u1ec1 t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng, kho\u1ea3ng 227.000 km\/s. M\u1eb7c d\u00f9 con s\u1ed1 n\u00e0y th\u1ea5p h\u01a1n kho\u1ea3ng 26% so v\u1edbi gi\u00e1 tr\u1ecb th\u1ef1c t\u1ebf ng\u00e0y nay, nh\u01b0ng \u0111\u00e2y l\u00e0 m\u1ed9t b\u01b0\u1edbc ngo\u1eb7t l\u1ecbch s\u1eed v\u0129 \u0111\u1ea1i, b\u00e1c b\u1ecf quan ni\u1ec7m ng\u00e0n n\u0103m v\u1ec1 s\u1ef1 truy\u1ec1n \u00e1nh s\u00e1ng t\u1ee9c th\u1eddi. Sau R\u00f8mer, nhi\u1ec1u nh\u00e0 khoa h\u1ecdc kh\u00e1c nh\u01b0 Hippolyte Fizeau v\u00e0 L\u00e9on Foucault \u0111\u00e3 ph\u00e1t tri\u1ec3n c\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u0111o \u0111\u1ea1c tr\u00ean m\u1eb7t \u0111\u1ea5t s\u1eed d\u1ee5ng b\u00e1nh xe r\u0103ng c\u01b0a quay v\u00e0 g\u01b0\u01a1ng quay, gi\u00fap tinh ch\u1ec9nh con s\u1ed1 n\u00e0y v\u1edbi \u0111\u1ed9 ch\u00ednh x\u00e1c ng\u00e0y c\u00e0ng cao h\u01a1n qua t\u1eebng th\u1ebf k\u1ef7.<\/span><\/p>\n \u0110\u1ebfn th\u1ebf k\u1ef7 20, v\u1edbi s\u1ef1 ra \u0111\u1eddi c\u1ee7a c\u00f4ng ngh\u1ec7 laser v\u00e0 \u0111\u1ed3ng h\u1ed3 nguy\u00ean t\u1eed cesium c\u00f3 \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ef1c cao, vi\u1ec7c \u0111o \u0111\u1ea1c <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> \u0111\u00e3 \u0111\u1ea1t \u0111\u1ebfn gi\u1edbi h\u1ea1n c\u1ee7a sai s\u1ed1 th\u1ef1c nghi\u1ec7m. V\u00e0o n\u0103m 1983, t\u1ea1i H\u1ed9i ngh\u1ecb To\u00e0n th\u1ec3 v\u1ec1 C\u00e2n \u0111o (CGPM), c\u1ed9ng \u0111\u1ed3ng khoa h\u1ecdc qu\u1ed1c t\u1ebf \u0111\u00e3 \u0111i \u0111\u1ebfn m\u1ed9t quy\u1ebft \u0111\u1ecbnh mang t\u00ednh l\u1ecbch s\u1eed. Thay v\u00ec c\u1ed1 g\u1eafng \u0111o t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng ng\u00e0y c\u00e0ng ch\u00ednh x\u00e1c h\u01a1n, h\u1ecd \u0111\u00e3 \u0111\u1ecbnh ngh\u0129a l\u1ea1i \u0111\u01a1n v\u1ecb “m\u00e9t” d\u1ef1a tr\u00ean h\u1eb1ng s\u1ed1 c. Theo \u0111\u00f3, 1 m\u00e9t l\u00e0 qu\u00e3ng \u0111\u01b0\u1eddng \u00e1nh s\u00e1ng \u0111i \u0111\u01b0\u1ee3c trong ch\u00e2n kh\u00f4ng trong kho\u1ea3ng th\u1eddi gian 1\/299.792.458 gi\u00e2y.<\/span><\/p>\n Quy\u1ebft \u0111\u1ecbnh n\u0103m 1983 \u0111\u00e3 bi\u1ebfn t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng t\u1eeb m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng c\u1ea7n \u0111o \u0111\u1ea1c th\u00e0nh m\u1ed9t h\u1eb1ng s\u1ed1 \u0111\u1ecbnh ngh\u0129a tuy\u1ec7t \u0111\u1ed1i. \u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 gi\u00e1 tr\u1ecb c\u1ee7a c s\u1ebd kh\u00f4ng bao gi\u1edd thay \u0111\u1ed5i n\u1eefa trong h\u1ec7 th\u1ed1ng \u0111o l\u01b0\u1eddng c\u1ee7a ch\u00fang ta, v\u00e0 b\u1ea5t k\u1ef3 s\u1ef1 c\u1ea3i ti\u1ebfn n\u00e0o trong c\u00f4ng ngh\u1ec7 \u0111o l\u01b0\u1eddng s\u1ebd ch\u1ec9 l\u00e0m thay \u0111\u1ed5i \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a \u0111\u1ecbnh ngh\u0129a v\u1ec1 \u0111\u1ed9 d\u00e0i m\u00e9t m\u00e0 th\u00f4i.<\/span><\/p>\n Khi nh\u1eafc \u0111\u1ebfn con s\u1ed1 x\u1ea5p x\u1ec9 300.000 km\/s, ch\u00fang ta \u0111ang n\u00f3i \u0111\u1ebfn <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> t\u1ed1i \u0111a trong m\u00f4i tr\u01b0\u1eddng ch\u00e2n kh\u00f4ng ho\u00e0n h\u1ea3o. Tuy nhi\u00ean, trong th\u1ef1c t\u1ebf, \u00e1nh s\u00e1ng th\u01b0\u1eddng xuy\u00ean ph\u1ea3i di chuy\u1ec3n qua c\u00e1c m\u00f4i tr\u01b0\u1eddng v\u1eadt ch\u1ea5t nh\u01b0 kh\u00f4ng kh\u00ed, n\u01b0\u1edbc, th\u1ee7y tinh hay kim c\u01b0\u01a1ng. Khi \u0111i qua c\u00e1c m\u00f4i tr\u01b0\u1eddng n\u00e0y, t\u1ed1c \u0111\u1ed9 c\u1ee7a \u00e1nh s\u00e1ng s\u1ebd b\u1ecb gi\u1ea3m \u0111i do s\u1ef1 t\u01b0\u01a1ng t\u00e1c \u0111i\u1ec7n t\u1eeb gi\u1eefa c\u00e1c photon \u00e1nh s\u00e1ng v\u00e0 c\u00e1c h\u1ea1t mang \u0111i\u1ec7n (electron) trong c\u1ea5u tr\u00fac nguy\u00ean t\u1eed c\u1ee7a v\u1eadt li\u1ec7u. T\u1ef7 l\u1ec7 gi\u1eefa t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong ch\u00e2n kh\u00f4ng (c) v\u00e0 t\u1ed1c \u0111\u1ed9 trong m\u00f4i tr\u01b0\u1eddng (v) \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 chi\u1ebft su\u1ea5t (n), v\u1edbi c\u00f4ng th\u1ee9c n = c\/v.<\/span><\/p>\n Hi\u1ec3u bi\u1ebft v\u1ec1 t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong c\u00e1c m\u00f4i tr\u01b0\u1eddng kh\u00e1c nhau l\u00e0 c\u01a1 s\u1edf \u0111\u1ec3 ch\u1ebf t\u1ea1o c\u00e1c thi\u1ebft b\u1ecb quang h\u1ecdc nh\u01b0 k\u00ednh m\u1eaft, \u1ed1ng k\u00ednh m\u00e1y \u1ea3nh, k\u00ednh hi\u1ec3n vi v\u00e0 \u0111\u1eb7c bi\u1ec7t l\u00e0 c\u00f4ng ngh\u1ec7 s\u1ee3i quang, n\u01a1i \u00e1nh s\u00e1ng \u0111\u01b0\u1ee3c d\u1eabn truy\u1ec1n b\u00ean trong l\u00f5i th\u1ee7y tinh \u0111\u1ec3 truy\u1ec1n t\u1ea3i d\u1eef li\u1ec7u Internet \u0111i kh\u1eafp th\u1ebf gi\u1edbi.<\/span><\/p>\n T\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t con s\u1ed1 \u0111o v\u1eadn t\u1ed1c di chuy\u1ec3n, m\u00e0 n\u00f3 l\u00e0 h\u1eb1ng s\u1ed1 c\u1ea5u tr\u00fac c\u1ee7a v\u0169 tr\u1ee5, \u0111\u00f3ng vai tr\u00f2 then ch\u1ed1t trong nhi\u1ec1u l\u0129nh v\u1ef1c v\u1eadt l\u00fd t\u1eeb vi m\u00f4 \u0111\u1ebfn v\u0129 m\u00f4. T\u1ea7m quan tr\u1ecdng n\u1ed5i ti\u1ebfng nh\u1ea5t c\u1ee7a c n\u1eb1m trong ph\u01b0\u01a1ng tr\u00ecnh huy\u1ec1n tho\u1ea1i E=mc\u00b2 c\u1ee7a Albert Einstein, n\u01a1i <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> \u0111\u00f3ng vai tr\u00f2 trung t\u00e2m. Ph\u01b0\u01a1ng tr\u00ecnh n\u00e0y cho th\u1ea5y n\u0103ng l\u01b0\u1ee3ng (E) v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng (m) l\u00e0 hai m\u1eb7t c\u1ee7a c\u00f9ng m\u1ed9t \u0111\u1ed3ng xu, v\u00e0 ch\u00fang c\u00f3 th\u1ec3 chuy\u1ec3n h\u00f3a cho nhau th\u00f4ng qua b\u00ecnh ph\u01b0\u01a1ng t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng. V\u00ec c l\u00e0 m\u1ed9t con s\u1ed1 r\u1ea5t l\u1edbn, n\u00ean m\u1ed9t l\u01b0\u1ee3ng kh\u1ed1i l\u01b0\u1ee3ng c\u1ef1c nh\u1ecf c\u0169ng ch\u1ee9a \u0111\u1ef1ng m\u1ed9t ngu\u1ed3n n\u0103ng l\u01b0\u1ee3ng kh\u1ed5ng l\u1ed3.<\/span><\/p>\n Nh\u01b0 v\u1eady, h\u1eb1ng s\u1ed1 c l\u00e0 s\u1ee3i d\u00e2y li\u00ean k\u1ebft m\u1ecdi hi\u1ec7n t\u01b0\u1ee3ng v\u1eadt l\u00fd, t\u1eeb n\u0103ng l\u01b0\u1ee3ng c\u1ee7a m\u1ed9t nguy\u00ean t\u1eed nh\u1ecf b\u00e9 \u0111\u1ebfn c\u1ea5u tr\u00fac kh\u00f4ng-th\u1eddi gian c\u1ee7a to\u00e0n b\u1ed9 v\u0169 tr\u1ee5 bao la.<\/span><\/p>\n Theo Thuy\u1ebft t\u01b0\u01a1ng \u0111\u1ed1i h\u1eb9p, <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> trong ch\u00e2n kh\u00f4ng l\u00e0 gi\u1edbi h\u1ea1n t\u1ed1c \u0111\u1ed9 nghi\u00eam ng\u1eb7t \u0111\u1ed1i v\u1edbi b\u1ea5t k\u1ef3 v\u1eadt ch\u1ea5t n\u00e0o mang th\u00f4ng tin ho\u1eb7c n\u0103ng l\u01b0\u1ee3ng. Tuy nhi\u00ean, c\u00e2u h\u1ecfi “c\u00f3 g\u00ec nhanh h\u01a1n \u00e1nh s\u00e1ng kh\u00f4ng” lu\u00f4n l\u00e0 \u0111\u1ec1 t\u00e0i h\u1ea5p d\u1eabn v\u00e0 g\u00e2y nhi\u1ec1u tranh c\u00e3i. Trong th\u1ef1c t\u1ebf, c\u00f3 m\u1ed9t s\u1ed1 hi\u1ec7n t\u01b0\u1ee3ng v\u1eadt l\u00fd d\u01b0\u1eddng nh\u01b0 vi ph\u1ea1m quy t\u1eafc n\u00e0y, nh\u01b0ng khi xem x\u00e9t k\u1ef9 l\u01b0\u1ee1ng, ch\u00fang kh\u00f4ng h\u1ec1 m\u00e2u thu\u1eabn v\u1edbi nguy\u00ean l\u00fd c\u1ee7a Einstein.<\/span><\/p>\n Tr\u01b0\u1eddng h\u1ee3p ph\u1ed5 bi\u1ebfn nh\u1ea5t th\u01b0\u1eddng \u0111\u01b0\u1ee3c nh\u1eafc \u0111\u1ebfn l\u00e0 s\u1ef1 gi\u00e3n n\u1edf c\u1ee7a v\u0169 tr\u1ee5. C\u00e1c thi\u00ean h\u00e0 \u1edf r\u1ea5t xa Tr\u00e1i \u0110\u1ea5t \u0111ang r\u1eddi xa ch\u00fang ta v\u1edbi t\u1ed1c \u0111\u1ed9 nhanh h\u01a1n \u00e1nh s\u00e1ng. Tuy nhi\u00ean, \u0111i\u1ec1u n\u00e0y kh\u00f4ng ph\u1ea3i do c\u00e1c thi\u00ean h\u00e0 t\u1ef1 di chuy\u1ec3n trong kh\u00f4ng gian nhanh h\u01a1n c, m\u00e0 l\u00e0 do ch\u00ednh kh\u00f4ng gian gi\u1eefa c\u00e1c thi\u00ean h\u00e0 \u0111ang gi\u00e3n n\u1edf.\u00a0<\/span><\/p>\n Ngo\u00e0i ra, trong m\u00f4i tr\u01b0\u1eddng v\u1eadt ch\u1ea5t (nh\u01b0 n\u01b0\u1edbc), c\u00e1c h\u1ea1t c\u00f3 th\u1ec3 di chuy\u1ec3n nhanh h\u01a1n \u00e1nh s\u00e1ng *trong m\u00f4i tr\u01b0\u1eddng \u0111\u00f3* (nh\u01b0ng v\u1eabn ch\u1eadm h\u01a1n c trong ch\u00e2n kh\u00f4ng).\u00a0<\/span><\/p>\n M\u1eb7c d\u00f9 <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> l\u00e0 m\u1ed9t h\u1eb1ng s\u1ed1 v\u1eadt l\u00fd c\u00f3 v\u1ebb tr\u1eebu t\u01b0\u1ee3ng, nh\u01b0ng n\u00f3 l\u1ea1i l\u00e0 n\u1ec1n t\u1ea3ng cho v\u00f4 s\u1ed1 c\u00f4ng ngh\u1ec7 hi\u1ec7n \u0111\u1ea1i m\u00e0 ch\u00fang ta s\u1eed d\u1ee5ng h\u00e0ng ng\u00e0y. \u1ee8ng d\u1ee5ng ph\u1ed5 bi\u1ebfn v\u00e0 quan tr\u1ecdng nh\u1ea5t ch\u00ednh l\u00e0 c\u00f4ng ngh\u1ec7 c\u00e1p quang. Internet to\u00e0n c\u1ea7u ho\u1ea1t \u0111\u1ed9ng d\u1ef1a tr\u00ean vi\u1ec7c truy\u1ec1n t\u1ea3i c\u00e1c xung \u00e1nh s\u00e1ng mang d\u1eef li\u1ec7u \u0111i qua c\u00e1c s\u1ee3i th\u1ee7y tinh m\u1ecfng v\u1edbi t\u1ed1c \u0111\u1ed9 \u0111\u1ea1t kho\u1ea3ng 200.000 km\/s (t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng trong th\u1ee7y tinh). Nh\u1edd t\u1ed1c \u0111\u1ed9 c\u1ef1c cao n\u00e0y, ch\u00fang ta c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n c\u00e1c cu\u1ed9c g\u1ecdi video th\u1eddi gian th\u1ef1c, giao d\u1ecbch t\u00e0i ch\u00ednh qu\u1ed1c t\u1ebf v\u00e0 truy c\u1eadp th\u00f4ng tin t\u1eeb n\u1eeda kia b\u00e1n c\u1ea7u ch\u1ec9 trong t\u00edch t\u1eafc.<\/span><\/p>\n C\u00f4ng ngh\u1ec7 Laser c\u0169ng l\u00e0 m\u1ed9t \u1ee9ng d\u1ee5ng tr\u1ef1c ti\u1ebfp kh\u00e1c. T\u1eeb c\u00e1c \u0111\u1ea7u \u0111\u1ecdc m\u00e3 v\u1ea1ch trong si\u00eau th\u1ecb, ph\u1eabu thu\u1eadt m\u1eaft LASIK trong y t\u1ebf, cho \u0111\u1ebfn c\u00e1c m\u00e1y c\u1eaft kim lo\u1ea1i ch\u00ednh x\u00e1c trong c\u00f4ng nghi\u1ec7p, t\u1ea5t c\u1ea3 \u0111\u1ec1u d\u1ef1a v\u00e0o t\u00ednh ch\u1ea5t v\u00e0 t\u1ed1c \u0111\u1ed9 c\u1ee7a ch\u00f9m tia s\u00e1ng t\u1eadp trung. Trong l\u0129nh v\u1ef1c \u0111o \u0111\u1ea1c, c\u00e1c thi\u1ebft b\u1ecb \u0111o kho\u1ea3ng c\u00e1ch b\u1eb1ng laser (LiDAR) \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i trong x\u00e2y d\u1ef1ng, tr\u1eafc \u0111\u1ecba v\u00e0 \u0111\u1eb7c bi\u1ec7t l\u00e0 trong c\u00f4ng ngh\u1ec7 xe t\u1ef1 l\u00e1i \u0111\u1ec3 l\u1eadp b\u1ea3n \u0111\u1ed3 m\u00f4i tr\u01b0\u1eddng xung quanh xe v\u1edbi t\u1ed1c \u0111\u1ed9 ph\u1ea3n h\u1ed3i t\u1ee9c th\u00ec.<\/span><\/p>\n Trong nghi\u00ean c\u1ee9u khoa h\u1ecdc, t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng cho ph\u00e9p c\u00e1c nh\u00e0 thi\u00ean v\u0103n h\u1ecdc nh\u00ecn ng\u01b0\u1ee3c v\u1ec1 qu\u00e1 kh\u1ee9. K\u00ednh vi\u1ec5n v\u1ecdng kh\u00f4ng gian Hubble v\u00e0 g\u1ea7n \u0111\u00e2y l\u00e0 James Webb ho\u1ea1t \u0111\u1ed9ng nh\u01b0 nh\u1eefng c\u1ed7 m\u00e1y th\u1eddi gian, thu nh\u1eadn \u00e1nh s\u00e1ng t\u1eeb c\u00e1c thi\u00ean h\u00e0 xa x\u00f4i nh\u01b0 GN-z11 (c\u00e1ch ch\u00fang ta 13,4 t\u1ef7 n\u0103m \u00e1nh s\u00e1ng).\u00a0<\/span><\/p>\n Ch\u1ee7 \u0111\u1ec1 v\u1ec1 <\/span>t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng<\/b> lu\u00f4n g\u1ee3i m\u1edf s\u1ef1 t\u00f2 m\u00f2 v\u00e0 \u0111i k\u00e8m v\u1edbi nhi\u1ec1u th\u1eafc m\u1eafc th\u00fa v\u1ecb. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 gi\u1ea3i \u0111\u00e1p cho nh\u1eefng c\u00e2u h\u1ecfi ph\u1ed5 bi\u1ebfn nh\u1ea5t m\u00e0 m\u1ecdi ng\u01b0\u1eddi th\u01b0\u1eddng \u0111\u1eb7t ra khi t\u00ecm hi\u1ec3u v\u1ec1 h\u1eb1ng s\u1ed1 v\u1eadt l\u00fd \u0111\u1eb7c bi\u1ec7t n\u00e0y, gi\u00fap quy \u0111\u1ed5i c\u00e1c con s\u1ed1 kh\u1ed5ng l\u1ed3 v\u1ec1 c\u00e1c \u0111\u01a1n v\u1ecb quen thu\u1ed9c h\u01a1n.<\/span><\/p>\n T\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng b\u1eb1ng bao nhi\u00eau km\/h? <\/b>X\u1ea5p x\u1ec9 <\/span>1.079.252.848 km\/h<\/b>. M\u1ed9t con s\u1ed1 kh\u1ed5ng l\u1ed3 v\u01b0\u1ee3t xa m\u1ecdi ph\u01b0\u01a1ng ti\u1ec7n nh\u00e2n t\u1ea1o.<\/span><\/p>\n 1 gi\u00e2y \u00e1nh s\u00e1ng b\u1eb1ng bao nhi\u00eau km? <\/b>Trong 1 gi\u00e2y, \u00e1nh s\u00e1ng \u0111i \u0111\u01b0\u1ee3c <\/span>299.792 km<\/b>, \u0111\u1ee7 \u0111\u1ec3 quay quanh Tr\u00e1i \u0110\u1ea5t h\u01a1n 7,5 v\u00f2ng.<\/span><\/p>\n T\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng so v\u1edbi \u00e2m thanh? <\/b>\u00c1nh s\u00e1ng (trong ch\u00e2n kh\u00f4ng) nhanh g\u1ea5p kho\u1ea3ng <\/span>874.030 l\u1ea7n<\/b> so v\u1edbi \u00e2m thanh (trong kh\u00f4ng kh\u00ed).<\/span><\/p>\n M\u1ea5t bao l\u00e2u \u0111\u1ec3 \u00e1nh s\u00e1ng t\u1eeb M\u1eb7t Tr\u1eddi \u0111\u1ebfn Tr\u00e1i \u0110\u1ea5t? <\/b>Trung b\u00ecnh kho\u1ea3ng <\/span>8 ph\u00fat 20 gi\u00e2y<\/b>. N\u1ebfu M\u1eb7t Tr\u1eddi t\u1eaft ng\u1ea5m ngay b\u00e2y gi\u1edd, h\u01a1n 8 ph\u00fat sau ch\u00fang ta m\u1edbi bi\u1ebft.<\/span><\/p>\n C\u00f3 c\u00e1ch n\u00e0o \u0111i nhanh h\u01a1n \u00e1nh s\u00e1ng (FTL) kh\u00f4ng? <\/b>V\u1ec1 m\u1eb7t v\u1eadt l\u00fd th\u1ef1c nghi\u1ec7m hi\u1ec7n t\u1ea1i l\u00e0 KH\u00d4NG. C\u00e1c kh\u00e1i ni\u1ec7m nh\u01b0 Wormhole hay Warp drive v\u1eabn ch\u1ec9 n\u1eb1m tr\u00ean l\u00fd thuy\u1ebft to\u00e1n h\u1ecdc.<\/span><\/p>\n Nh\u1eefng con s\u1ed1 v\u00e0 s\u1ef1 ki\u1ec7n n\u00e0y nh\u1eafc nh\u1edf ch\u00fang ta v\u1ec1 s\u1ef1 gi\u1edbi h\u1ea1n c\u1ee7a con ng\u01b0\u1eddi tr\u01b0\u1edbc s\u1ef1 v\u0129 \u0111\u1ea1i c\u1ee7a c\u00e1c quy lu\u1eadt v\u1eadt l\u00fd, \u0111\u1ed3ng th\u1eddi kh\u01a1i d\u1eady kh\u00e1t v\u1ecdng kh\u00e1m ph\u00e1 nh\u1eefng ch\u00e2n tr\u1eddi m\u1edbi trong khoa h\u1ecdc v\u0169 tr\u1ee5.<\/span><\/p>\n T\u00f3m l\u1ea1i, vi\u1ec7c t\u00ecm hi\u1ec3u t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng l\u00e0 bao nhi\u00eau km\/s gi\u00fap ch\u00fang ta hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 nh\u1eefng quy lu\u1eadt n\u1ec1n t\u1ea3ng chi ph\u1ed1i v\u0169 tr\u1ee5. V\u1edbi gi\u00e1 tr\u1ecb ch\u00ednh x\u00e1c kho\u1ea3ng 299.792 km\/s, t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng kh\u00f4ng ch\u1ec9 \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong v\u1eadt l\u00fd hi\u1ec7n \u0111\u1ea1i m\u00e0 c\u00f2n l\u00e0 c\u01a1 s\u1edf cho nhi\u1ec1u \u1ee9ng d\u1ee5ng c\u00f4ng ngh\u1ec7 v\u00e0 nghi\u00ean c\u1ee9u thi\u00ean v\u0103n.<\/p>\n Xem th\u00eam:<\/p>\nL\u1ecbch s\u1eed ph\u00e1t tri\u1ec3n<\/strong><\/h3>\n
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<\/p>\nL\u1ecbch S\u1eed \u0110o L\u01b0\u1eddng T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng<\/b><\/h2>\n
Th\u1ebf k\u1ef7 17<\/strong><\/h3>\n
<\/p>\nTh\u1ebf k\u1ef7 20<\/strong><\/h3>\n
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<\/p>\nT\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng Trong C\u00e1c M\u00f4i Tr\u01b0\u1eddng Kh\u00e1c<\/b><\/h2>\n
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<\/p>\nT\u1ea1i Sao T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng Quan Tr\u1ecdng Trong V\u1eadt L\u00fd?<\/b><\/h2>\n
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<\/p>\nTrong V\u0169 Tr\u1ee5 C\u00f3 Th\u1ee9 G\u00ec Nhanh H\u01a1n \u00c1nh S\u00e1ng Kh\u00f4ng?<\/b><\/h2>\n
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<\/p>\n\u1ee8ng D\u1ee5ng Th\u1ef1c T\u1ebf C\u1ee7a T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng<\/b><\/h2>\n
<\/p>\nC\u00e2u H\u1ecfi Th\u01b0\u1eddng G\u1eb7p V\u1ec1 T\u1ed1c \u0110\u1ed9 \u00c1nh S\u00e1ng (FAQ)<\/b><\/h2>\n
<\/p>\nT\u1ea1m k\u1ebft<\/strong><\/h2>\n