在微波炉里放一块巧克力，看哪融化，真能“量”出光速吗？
Can you really 'measure' the speed of light with chocolate in a microwave?
微波炉里的微波形成驻波，只有某些点最热。量出两块融化区的距离就是半个波长，再乘已知的微波频率，就能算出光速。方法粗糙但原理和科学家一样。
Microwave energy forms standing waves with hot spots. Measuring the gap between two melted spots gives half a wavelength; multiply by the known microwave frequency and you get the speed of light. Crude, but the principle matches the real method.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
A. A. Michelson,《Measurement of the Velocity of Light Between Mount Wilson and Mount San Antonio》,The Astrophysical Journal 65, 1,1927 (DOI: 10.1086/143021)
A. A. Michelson, 'Measurement of the Velocity of Light Between Mount Wilson and Mount San Antonio', The Astrophysical Journal 65, 1, 1927, DOI: 10.1086/143021
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1086/143021
#微波炉 #驻波 #光速
为什么先看到闪电、后听到雷声，还能用它估出雷暴离你多远？
Why do we see lightning before thunder — and can that tell how far the storm is?
光比声音快得多：闪电的光几乎瞬间到，雷声却要慢慢爬。看到闪后数几秒才听到雷，用“秒数÷3”大约就是多少公里远。
Light is far faster than sound: the flash arrives instantly, thunder crawls. Count seconds after the flash until thunder; divide by 3 for roughly the distance in kilometers.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 4 条独立证据
来源 · Source
Halliday, Resnick, Walker,《Fundamentals of Physics》第10版,Wiley,2013
David Halliday, Robert Resnick, Jearl Walker, Fundamentals of Physics, 10th ed., Wiley, 2013
独立核验依据 · Independent verification: 核验依据 3 angusrobertson.com.au
#闪电 #雷声 #测距
用一根棍子和它的影子，怎么在没有尺子时估出大树的高度？
With just a stick and its shadow, how can you estimate a tree's height without a ruler?
同一时刻，实物和影子的长度比例对谁都一样（相似三角形）。量出小棍长、小棍影、大树影，用“树高/树影 = 棍长/棍影”一算就出来了。
At the same moment, the ratio of object to shadow is the same for everything (similar triangles). Measure stick, stick-shadow and tree-shadow, then tree height = stick × (tree-shadow / stick-shadow).
难度 入门 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Euclid（欧几里得）, 《Elements》（几何原本）
Euclid, Elements
独立核验依据 · Independent verification: 核验依据 1 ISBN 9780665590955 (2002)
#影子 #相似三角形 #估算