N\u1ebfu ng\u01b0\u1eddi ta h\u1ecfi b\u1ea1n: “s\u00f3ng \u00e1nh s\u00e1ng v\u00e0 s\u00f3ng \u0111i\u1ec7n, s\u00f3ng n\u00e0o truy\u1ec1n nhanh h\u01a1n? Ch\u1eafc ch\u1eafn b\u1ea1n s\u1ebd ngh\u0129, t\u1ea5t nhi\u00ean l\u00e0 s\u00f3ng \u00e1nh s\u00e1ng ch\u1ea1y nhanh h\u01a1n! M\u1ecdi ng\u01b0\u1eddi \u0111\u1ec1u bi\u1ebft, s\u00f3ng \u00e1nh s\u00e1ng l\u00e0 th\u1ee9 ch\u1ea1y nhanh nh\u1ea5t tr\u00ean th\u1ebf gi\u1edbi. T\u1ed1c \u0111\u1ed9 lan truy\u1ec1n c\u1ee7a n\u00f3 l\u00e0 300.000 km\/s. Trong m\u1ed9t gi\u00e2y, n\u00f3 c\u00f3 th\u1ec3 chuy\u1ec3n \u0111\u1ed9ng quanh Tr\u00e1i \u0110\u1ea5t \u0111\u1ebfn 7,5 v\u00f2ng kia \u0111\u1ea5y!<\/p>\n\n\n\n
Ch\u00fang ta h\u00e3y xem x\u00e9t s\u00f3ng \u0111i\u1ec7n tr\u01b0\u1edbc \u0111\u00e3. S\u00f3ng \u0111i\u1ec7n t\u1ee9c l\u00e0 s\u00f3ng \u0111i\u1ec7n t\u1eeb. Ch\u00ednh l\u00e0 th\u00f4ng qua vi\u1ec7c ph\u00e1t x\u1ea1 s\u00f3ng \u0111i\u1ec7n t\u1eeb m\u00e0 \u0111\u00e0i ph\u00e1t thanh v\u00e0 \u0111\u00e0i truy\u1ec1n h\u00ecnh \u0111\u01b0a c\u00e1c ti\u1ebft m\u1ee5c \u0111\u1eb7c s\u1eafc \u0111\u1ebfn h\u00e0ng ng\u00e0n, h\u00e0ng v\u1ea1n gia \u0111\u00ecnh. Ch\u00fang ta v\u1eeba b\u1eadt ra\u0111i\u00f4 ho\u1eb7c tivi l\u00ean l\u00e0 l\u1eadp t\u1ee9c c\u00f3 th\u1ec3 thu nghe ho\u1eb7c thu nh\u00ecn \u0111\u01b0\u1ee3c c\u00e1c ti\u1ebft m\u1ee5c t\u1ea1i ch\u1ed7 c\u00e1ch xa t\u1edbi v\u00e0i ch\u1ee5c ngh\u00ecn kil\u00f4m\u00e9t. \u0110i\u1ec7n tho\u1ea1i di \u0111\u1ed9ng c\u0169ng c\u00f3 th\u1ec3 l\u1ee3i d\u1ee5ng s\u00f3ng \u0111i\u1ec7n t\u1eeb \u0111\u1ec3 truy\u1ec1n th\u00f4ng tin. Th\u00f4ng qua \u0111i\u1ec7n tho\u1ea1i di \u0111\u1ed9ng, b\u1ea1n chuy\u1ec7n tr\u00f2 c\u00f9ng ng\u01b0\u1eddi th\u00e2n ho\u1eb7c b\u1ea1n b\u00e8 c\u1ee9 nh\u01b0 l\u00e0 \u1edf b\u00ean c\u1ea1nh m\u00ecnh v\u1eady. Xem ra, t\u1ed1c \u0111\u1ed9 c\u1ee7a s\u00f3ng \u0111i\u1ec7n t\u1eeb ch\u1eafc c\u0169ng r\u1ea5t nhanh nh\u1ec9? \u0110\u00fang th\u1ebf! C\u00e1c nh\u00e0 khoa h\u1ecdc \u0111o \u0111\u01b0\u1ee3c t\u1ed1c \u0111\u1ed9 truy\u1ec1n c\u1ee7a s\u00f3ng \u0111i\u1ec7n t\u1eeb c\u0169ng l\u00e0 300.000 km\/s, kh\u00f4ng h\u1ec1 ch\u1eadm h\u01a1n s\u00f3ng \u00e1nh s\u00e1ng t\u00ed n\u00e0o!<\/p>\n\n\n\n
T\u1ed1c \u0111\u1ed9 c\u1ee7a s\u00f3ng \u00e1nh s\u00e1ng v\u00e0 s\u00f3ng \u0111i\u1ec7n t\u1eeb b\u1eb1ng nhau, \u0111\u00f3 thu\u1ea7n tu\u00fd ch\u1ec9 l\u00e0 m\u1ed9t lo\u1ea1i tr\u00f9ng h\u1ee3p ng\u1eabu nhi\u00ean ch\u0103ng? C\u1ed1 nhi\u00ean l\u00e0 kh\u00f4ng! N\u0103m 1865, nh\u00e0 v\u1eadt l\u00ed ng\u01b0\u1eddi Anh, Maxwell, \u0111\u00e3 d\u00f9ng nh\u00f3m ph\u01b0\u01a1ng tr\u00ecnh c\u1ee7a \u00f4ng, t\u00ednh ra t\u1ed1c \u0111\u1ed9 c\u1ee7a s\u00f3ng \u0111i\u1ec7n t\u1eeb b\u1eb1ng v\u1edbi t\u1ed1c \u0111\u1ed9 c\u1ee7a \u00e1nh s\u00e1ng, v\u00e0 d\u1ef1a v\u00e0o \u0111\u00f3 m\u00e0 m\u1ea1nh d\u1ea1n d\u1ef1 \u0111o\u00e1n: \u00e1nh s\u00e1ng \u0111\u00fang l\u00e0 m\u1ed9t lo\u1ea1i s\u00f3ng \u0111i\u1ec7n t\u1eeb. L\u00e0m sao c\u00f3 th\u1ec3 nh\u1eadp \u00e1nh s\u00e1ng v\u00e0o s\u00f3ng \u0111i\u1ec7n t\u1eeb \u0111\u01b0\u1ee3c? Ch\u00fang ta c\u00f3 th\u1ec3 nh\u00ecn th\u1ea5y \u00e1nh s\u00e1ng, song l\u1ea1i ch\u1eb3ng h\u1ec1 nghe n\u00f3i c\u00f3 th\u1ec3 tr\u00f4ng th\u1ea5y s\u00f3ng \u0111i\u1ec7n t\u1eeb c\u1ee7a \u0111\u00e0i ph\u00e1t thanh, \u0111\u00e0i truy\u1ec1n h\u00ecnh ph\u00e1t ra. K\u00ec th\u1ef1c th\u00ec \u0111\u00f3 l\u00e0 b\u1edfi l\u00ed do t\u1ea7n s\u1ed1 c\u1ee7a ch\u00fang kh\u00e1c nhau \u0111\u1ea5y th\u00f4i. S\u00f3ng \u0111i\u1ec7n t\u1eeb m\u00e0 m\u1eaft ng\u01b0\u1eddi c\u00f3 th\u1ec3 nh\u00ecn th\u1ea5y ch\u1ec9 l\u00e0 m\u1ed9t d\u1ea3i r\u1ea5t h\u1eb9p, ch\u1ec9 c\u00f3 s\u00f3ng \u0111i\u1ec7n t\u1eeb t\u1ea7n s\u1ed1 t\u1eeb 410 tri\u1ec7u – 770 tri\u1ec7u megahec m\u1edbi c\u00f3 th\u1ec3 k\u00edch th\u00edch th\u1ecb gi\u00e1c c\u1ee7a ng\u01b0\u1eddi. \u0110\u00f3 t\u1ee9c l\u00e0 \u00e1nh s\u00e1ng nh\u00ecn th\u1ea5y. S\u00f3ng \u0111i\u1ec7n t\u1eeb c\u00f3 t\u1ea7n s\u1ed1 cao h\u01a1n \u00e1nh s\u00e1ng nh\u00ecn th\u1ea5y l\u1ea7n l\u01b0\u1ee3t l\u00e0 tia t\u1eed ngo\u1ea1i, tia X, tia \u03b3. C\u00f2n s\u00f3ng \u0111i\u1ec7n t\u1eeb c\u00f3 t\u1ea7n s\u1ed1 th\u1ea5p h\u01a1n \u00e1nh s\u00e1ng nh\u00ecn th\u1ea5y l\u00e0 tia h\u1ed3ng ngo\u1ea1i, vi s\u00f3ng, s\u00f3ng v\u00f4 tuy\u1ebfn \u0111i\u1ec7n v.v. Nh\u1eefng s\u00f3ng \u0111i\u1ec7n t\u1eeb n\u00e0y kh\u00f4ng sao k\u00edch th\u00edch \u0111\u01b0\u1ee3c th\u1ecb gi\u00e1c c\u1ee7a ng\u01b0\u1eddi, m\u1eaft ch\u00fang ta kh\u00f4ng nh\u00ecn th\u1ea5y \u0111\u01b0\u1ee3c.<\/p>\n\n\n\n
S\u00f3ng \u0111i\u1ec7n t\u1eeb do \u0111\u00e0i ph\u00e1t thanh, \u0111\u00e0i truy\u1ec1n h\u00ecnh ph\u00e1t ra l\u00e0 s\u00f3ng v\u00f4 tuy\u1ebfn \u0111i\u1ec7n c\u00f3 t\u1ea7n s\u1ed1 t\u1eeb v\u00e0i tr\u0103m kilohec \u0111\u1ebfn v\u00e0i ch\u1ee5c ngh\u00ecn megahec. V\u00ed d\u1ee5 nh\u01b0 \u0110\u00e0i ph\u00e1t thanh Nh\u00e2n d\u00e2n c\u1ee7a th\u00e0nh ph\u1ed1 Th\u01b0\u1ee3ng H\u1ea3i s\u1eed d\u1ee5ng s\u00f3ng \u0111i\u1ec7n t\u1eeb c\u00f3 t\u1ea7n s\u1ed1 990 kilohec, c\u00f2n \u0111i\u1ec1u t\u1ea7n FM \u1edf \u0111\u00f3 s\u1eed d\u1ee5ng s\u00f3ng \u0111i\u1ec7n t\u1eeb c\u00f3 t\u1ea7n s\u1ed1 l\u00e0 103,7 megahec. T\u1ea7n s\u1ed1 c\u1ee7a ch\u00fang c\u00e1ch bi\u1ec7t r\u1ea5t xa v\u1edbi t\u1ea7n s\u1ed1 c\u1ee7a \u00e1nh s\u00e1ng nh\u00ecn th\u1ea5y, cho n\u00ean m\u1eaft ng\u01b0\u1eddi ho\u00e0n to\u00e0n kh\u00f4ng nh\u00ecn th\u1ea5y \u0111\u01b0\u1ee3c.<\/p>\n\n\n\n
\u00c1nh s\u00e1ng v\u00e0 s\u00f3ng \u0111i\u1ec7n ph\u00e1t ra t\u1eeb \u0111\u00e0i ph\u00e1t thanh v\u00e0 \u0111\u00e0i truy\u1ec1n h\u00ecnh \u0111\u1ec1u l\u00e0 s\u00f3ng \u0111i\u1ec7n t\u1eeb c\u1ea3, ch\u1ec9 c\u00f3 d\u1ea3i t\u1ea7n s\u1ed1 c\u1ee7a hai lo\u1ea1i \u0111\u00f3 kh\u00e1c nhau, m\u00e0 t\u1ed1c \u0111\u1ed9 truy\u1ec1n c\u1ee7a s\u00f3ng \u0111i\u1ec7n t\u1eeb kh\u00f4ng li\u00ean quan g\u00ec v\u1edbi t\u1ea7n s\u1ed1, v\u00ec v\u1eady t\u1ed1c \u0111\u1ed9 c\u1ee7a s\u00f3ng \u00e1nh s\u00e1ng v\u00e0 s\u00f3ng \u0111i\u1ec7n b\u1eb1ng nhau l\u00e0 \u0111i\u1ec1u t\u1ea5t nhi\u00ean r\u1ed3i.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: S\u00f3ng \u00e1nh s\u00e1ng; T\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng;S\u00f3ng \u0111i\u1ec7n; S\u00f3ng \u0111i\u1ec7n t\u1eeb.<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
N\u1ebfu ng\u01b0\u1eddi ta h\u1ecfi b\u1ea1n: “s\u00f3ng \u00e1nh s\u00e1ng v\u00e0 s\u00f3ng \u0111i\u1ec7n, s\u00f3ng n\u00e0o truy\u1ec1n nhanh h\u01a1n? Ch\u1eafc ch\u1eafn b\u1ea1n s\u1ebd ngh\u0129, t\u1ea5t nhi\u00ean l\u00e0 s\u00f3ng \u00e1nh s\u00e1ng ch\u1ea1y nhanh h\u01a1n! M\u1ecdi ng\u01b0\u1eddi \u0111\u1ec1u bi\u1ebft, s\u00f3ng \u00e1nh s\u00e1ng l\u00e0 th\u1ee9 ch\u1ea1y nhanh nh\u1ea5t tr\u00ean th\u1ebf gi\u1edbi. T\u1ed1c \u0111\u1ed9 lan truy\u1ec1n c\u1ee7a n\u00f3 l\u00e0 300.000 km\/s. Trong […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,7],"tags":[],"class_list":["post-5742","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-vat-ly"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5742","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=5742"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5742\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=5742"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=5742"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=5742"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}