K\u00ednh l\u00fap l\u00e0 m\u1ed9t lo\u1ea1i kh\u00ed c\u1ee5 quang h\u1ecdc \u0111\u01a1n gi\u1ea3n, d\u00f9ng n\u00f3 \u0111\u1ec3 \u0111\u1ecdc s\u00e1ch th\u00ec n\u00e9t ch\u1eef nh\u1ecf \u0111\u01b0\u1ee3c ph\u00f3ng to l\u00ean, nh\u00ecn r\u1ea5t r\u00f5 n\u00e9t. K\u00ednh l\u00fap \u0111\u01b0\u1ee3c ch\u1ebf ra b\u1eb1ng c\u00e1ch m\u00e0i ch\u1ea5t c\u00f3 \u0111\u1ed9 trong su\u1ed1t r\u1ea5t t\u1ed1t (nh\u01b0 thu\u1ef7 tinh). N\u00f3 d\u00e0y \u1edf gi\u1eefa, m\u1ecfng \u1edf m\u00e9p vi\u1ec1n, l\u00e0 m\u1ed9t mi\u1ebfng th\u1ea5u k\u00ednh l\u1ed3i. Hai m\u1eb7t c\u1ee7a n\u00f3 c\u00f3 th\u1ec3 \u0111\u1ec1u l\u00e0 m\u1eb7t c\u1ea7u, ho\u1eb7c m\u1ed9t m\u1eb7t l\u00e0 m\u1eb7t c\u1ea7u, m\u1eb7t kia ph\u1eb3ng.<\/p>\n\n\n\n
\u0110\u1eb7t m\u1ed9t k\u00ednh l\u00fap h\u01b0\u1edbng v\u1ec1 ph\u00eda \u00e1nh M\u1eb7t Tr\u1eddi (th\u1ea5u k\u00ednh th\u1eb3ng g\u00f3c v\u1edbi tia s\u00e1ng), tia s\u00e1ng \u0111i qua k\u00ednh l\u00fap s\u1ebd t\u1ee5 th\u00e0nh m\u1ed9t \u0111i\u1ec3m. \u0110i\u1ec3m \u0111\u00f3 t\u1ee9c l\u00e0 ti\u00eau \u0111i\u1ec3m. N\u1ebfu \u0111\u1eb7t \u0111\u1ea7u m\u1ed9t que di\u00eam \u0111\u00fang v\u00e0o ch\u1ed7 ti\u00eau \u0111i\u1ec3m, ch\u1eb3ng m\u1ea5y ch\u1ed1c que di\u00eam b\u00f9ng ch\u00e1y l\u00ean. Kho\u1ea3ng c\u00e1ch gi\u1eefa t\u00e2m th\u1ea5u k\u00ednh \u0111\u1ebfn ti\u00eau \u0111i\u1ec3m g\u1ecdi l\u00e0 ti\u00eau c\u1ef1.<\/p>\n\n\n\n
N\u1ebfu \u0111\u1eb7t m\u1ed9t v\u1eadt th\u1ec3 v\u00e0o trong ti\u00eau c\u1ef1 c\u1ee7a k\u00ednh l\u00fap, do th\u1ea5u k\u00ednh l\u1ed3i c\u00f3 t\u00ednh n\u0103ng t\u1ee5 quang, ng\u01b0\u1eddi quan s\u00e1t li\u1ec1n c\u00f3 th\u1ec3 th\u1ea5y \u0111\u01b0\u1ee3c m\u1ed9t \u1ea3nh \u1ea3o \u0111\u01b0\u1ee3c ph\u00f3ng to \u1edf m\u1ed9t n\u01a1i l\u1edbn h\u01a1n c\u1ef1 li c\u1ee7a v\u1eadt. Nh\u01b0 v\u1eady, b\u1ed9 ph\u1eadn nh\u1ecf x\u00edu v\u1ed1n nh\u00ecn kh\u00f4ng r\u00f5, th\u00f4ng qua t\u00e1c d\u1ee5ng ph\u00f3ng to c\u1ee7a k\u00ednh l\u00fap, li\u1ec1n c\u00f3 th\u1ec3 th\u1ea5y r\u00f5 r\u00e0ng h\u01a1n.<\/p>\n\n\n\n
\u0110\u1ed9 ph\u00f3ng \u0111\u1ea1i c\u1ee7a k\u00ednh l\u00fap n\u00f3i \u0111\u1ebfn trong quang h\u1ecdc l\u00e0 x\u00e9t t\u1eeb g\u00f3c \u0111\u1ed9 c\u1ee7a “g\u00f3c nh\u00ecn”. N\u1ebfu d\u00f9ng ra\u0111ian \u0111\u1ec3 bi\u1ec3u th\u1ecb g\u00f3c nh\u00ecn, \u0111\u1ed9 l\u1edbn c\u1ee7a n\u00f3 b\u1eb1ng t\u1ec9 l\u1ec7 gi\u1eefa \u0111\u1ed9 d\u00e0i c\u1ee7a v\u1eb7t th\u1ec3 v\u1edbi kho\u1ea3ng c\u00e1ch t\u1eeb m\u1eaft \u0111\u1ebfn v\u1eadt. Khi g\u00f3c nh\u00ecn nh\u1ecf h\u01a1n 1′ (t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi g\u00f3c nh\u00ecn c\u1ee7a m\u1ed9t v\u1eadt d\u00e0i 1 cm \u1edf c\u00e1ch m\u1eaft ngo\u00e0i 34 m). Trong tr\u01b0\u1eddng h\u1ee3p \u00e1nh s\u00e1ng c\u1ee7a m\u00f4i tr\u01b0\u1eddng xung quanh kh\u00f4ng t\u1ed1t, g\u00f3c nh\u00ecn \u0111\u00f3 ph\u1ea3i \u0111\u01b0\u1ee3c t\u0103ng l\u00ean, th\u1eadm ch\u00ed \u0111\u1ea1t t\u1edbi 1\u00b0 m\u1edbi \u0111\u01b0\u1ee3c.<\/p>\n\n\n\n
T\u00e1c d\u1ee5ng c\u1ee7a k\u00ednh l\u00fap l\u00e0 th\u00f4ng qua vi\u1ec7c l\u00e0m t\u0103ng g\u00f3c nh\u00ecn m\u00e0 \u0111\u1ea1t \u0111\u01b0\u1ee3c m\u1ee5c \u0111\u00edch ph\u00f3ng to \u1ea3nh v\u1eadt. Theo t\u00ednh to\u00e1n, \u0111\u1ed9 ph\u00f3ng \u0111\u1ea1i c\u1ee7a k\u00ednh l\u00fap b\u1eb1ng kho\u1ea3ng c\u00e1ch th\u1ea5y r\u00f5 chia cho kho\u1ea3ng c\u00e1ch gi\u1eefa v\u1eadt th\u1ec3 v\u00e0 m\u1eaft.<\/p>\n\n\n\n
D\u00f9ng k\u00ednh l\u00fap xem v\u1eadt, ph\u1ea3i \u0111\u1eb7t v\u1eadt th\u1ec3 b\u00ean trong ti\u00eau c\u1ef1. Ti\u00eau c\u1ef1 c\u1ee7a k\u00ednh l\u00fap trong kho\u1ea3ng 1,0 – 10 cm, kho\u1ea3ng c\u00e1ch th\u1ea5y r\u00f5 l\u00e0 25 cm, cho n\u00ean \u0111\u1ed9 ph\u00f3ng \u0111\u1ea1i c\u1ee7a k\u00ednh l\u00fap \u1edf gi\u1eefa 2,5 – 25 l\u1ea7n.<\/p>\n\n\n\n
K\u00ednh l\u00e3o m\u00e0 ng\u01b0\u1eddi gi\u00e0 d\u00f9ng c\u0169ng l\u00e0 m\u1ed9t lo\u1ea1i th\u1ea5u k\u00ednh l\u1ed3i. Ai c\u0169ng bi\u1ebft r\u1eb1ng, \u00e1nh s\u00e1ng c\u1ee7a v\u1eadt th\u1ec3 ph\u00e1t ra ch\u1ec9 c\u00f3 th\u00f4ng qua t\u00e1c d\u1ee5ng kh\u00fac x\u1ea1 c\u1ee7a thu\u1ef7 tinh th\u1ec3 trong nh\u00e3 n c\u1ea7u, h\u1ed9i t\u1ee5 \u0111\u1ebfn v\u00f5ng m\u1ea1c nh\u00ecn tr\u00ean v\u00e1ch sau c\u1ee7a nh\u00e3 n c\u1ea7u th\u00ec m\u1edbi \u0111\u01b0\u1ee3c th\u1ea5y r\u00f5. Khi nh\u00ecn v\u1eadt th\u1ec3 r\u1ea5t xa, m\u1eaft c\u00f3 th\u1ec3 \u1edf v\u00e0o tr\u1ea1ng th\u00e1i bu\u00f4ng l\u1ecfng, tr\u00ean v\u00f5ng m\u1ea1c nh\u00ecn th\u00e0nh \u1ea3nh r\u00f5 r\u1ec7t. Nh\u01b0ng nh\u00ecn v\u00e0o v\u1eadt th\u1ec3 \u1edf g\u1ea7n th\u00ec ph\u1ea3i \u0111i\u1ec1u ti\u1ebft m\u1eaft \u0111\u1ec3 l\u00e0m t\u0103ng chi\u1ebft su\u1ea5t c\u1ee7a thu\u1ef7 tinh th\u1ec3. V\u00ec n\u0103ng l\u1ef1c \u0111i\u1ec1u ti\u1ebft c\u1ee7a ng\u01b0\u1eddi gi\u00e0 \u0111\u00e3 suy tho\u00e1i, \u0111\u1ebfn n\u1ed7i ch\u1ec9 c\u00f3 th\u1ec3 \u0111\u1ec3 tia s\u00e1ng h\u1ed9i t\u1ee5 \u1edf \u0111\u1eb1ng sau c\u1ee7a v\u00f5ng m\u1ea1c m\u1eaft. \u0110\u1eb7t m\u1ed9t th\u1ea5u k\u00ednh l\u1ed3i tr\u01b0\u1edbc con m\u1eaft, \u0111\u1ec3 tia s\u00e1ng h\u1ed9i t\u1ee5 th\u00eam m\u1ed9t l\u1ea7n th\u00ec c\u00f3 th\u1ec3 l\u00e0m cho \u1ea3nh r\u01a1i v\u00e0o v\u00f5ng m\u1ea1c, m\u1eaft ng\u01b0\u1eddi gi\u00e0 nh\u1edd \u0111\u00f3 m\u1edbi kh\u00f4ng m\u1edd t\u1ed1i.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: Th\u1ea5u k\u00ednh l\u1ed3i; K\u00ednh l\u00fap; K\u00ednh l\u00e3o; \u0110\u1ed9 ph\u00f3ng \u0111\u1ea1i; G\u00f3c nh\u00ecn;<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
K\u00ednh l\u00fap l\u00e0 m\u1ed9t lo\u1ea1i kh\u00ed c\u1ee5 quang h\u1ecdc \u0111\u01a1n gi\u1ea3n, d\u00f9ng n\u00f3 \u0111\u1ec3 \u0111\u1ecdc s\u00e1ch th\u00ec n\u00e9t ch\u1eef nh\u1ecf \u0111\u01b0\u1ee3c ph\u00f3ng to l\u00ean, nh\u00ecn r\u1ea5t r\u00f5 n\u00e9t. K\u00ednh l\u00fap \u0111\u01b0\u1ee3c ch\u1ebf ra b\u1eb1ng c\u00e1ch m\u00e0i ch\u1ea5t c\u00f3 \u0111\u1ed9 trong su\u1ed1t r\u1ea5t t\u1ed1t (nh\u01b0 thu\u1ef7 tinh). N\u00f3 d\u00e0y \u1edf gi\u1eefa, m\u1ecfng \u1edf m\u00e9p vi\u1ec1n, l\u00e0 […]<\/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-5782","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\/5782","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=5782"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5782\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=5782"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=5782"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=5782"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}