Physics Stack Exchange by Kiwix

Q&A for active researchers, academics and students of physics

Most popular questions

599 Cooling a cup of coffee with help of a spoon 2011-02-16T12:09:27.020

384 Can I compute the mass of a coin based on the sound of its fall? 2014-06-26T11:27:38.900

344 How does light bend around my finger tip? 2014-05-03T00:20:47.187

338 How does gravity escape a black hole? 2010-11-16T17:39:59.213

281 A mirror flips left and right, but not up and down 2011-04-07T19:39:39.457

278 Book recommendations 2011-07-12T06:04:21.747

250 Do we know why there is a speed limit in our universe? 2016-01-20T17:07:17.560

243 Why don't metals bond when touched together? 2013-11-19T18:29:00.520

242 Why do ballpoint pens write better on pages that have pages below them? 2017-10-08T13:39:06.593

236 What experiment would disprove string theory? 2010-11-02T19:51:03.887

212 If I sliced the universe in half, would the slice go through a star? 2018-02-26T12:15:12.960

211 Why are four-legged chairs so common? 2016-01-20T15:58:46.377

211 How do towels stay on hooks? 2018-01-23T21:10:25.330

206 What really allows airplanes to fly? 2010-11-06T03:23:18.563

201 Did the Big Bang happen at a point? 2014-09-23T10:03:58.110

193 Don't heavier objects actually fall faster because they exert their own gravity? 2011-01-21T20:10:15.837

186 Why is the detection of gravitational waves so significant? 2016-02-11T14:18:42.637

181 Surviving under water in air bubble 2013-06-13T21:56:04.640

178 Why does kinetic energy increase quadratically, not linearly, with speed? 2010-11-10T23:59:43.297

177 Strange ice found in my garden 2018-02-22T09:58:09.703

170 What exactly is a photon? 2016-08-07T10:27:03.637

168 Does Earth really have two high-tide bulges on opposite sides? 2014-06-25T21:59:42.257

158 When separating an Oreo cookie, why does the cream stick to just one side only? 2017-05-31T20:24:18.367

155 Why does NASA use gold foil on equipment and gold-coated visors? 2013-08-17T11:03:26.700

151 How does a knife cut things at the atomic level? 2014-09-05T18:09:07.077

147 Are units of angle really dimensionless? 2016-04-27T00:54:45.537

146 Could Legolas actually see that far? 2014-07-02T16:54:49.210

146 Why doesn't matter pass through other matter if atoms are 99.999% empty space? 2014-07-14T19:36:10.020

145 How do I explain to a six year old why people on the other side of the Earth don't fall off? 2014-01-20T13:29:55.347

141 Stupid yet tricky question: Why do we actually see the sun? 2013-07-03T19:52:25.150

141 Why do sunbeams diverge even though the sun is much more than a few kilometers away? 2014-12-25T11:14:54.877

140 Why does Stephen Hawking say black holes don't exist? 2014-01-26T15:44:30.467

138 Why do shadows from the sun join each other when near enough? 2014-01-18T15:15:04.017

134 Why is my hand not burned by the air in an oven at 200°C? 2017-01-28T18:50:27.967

133 Why is nuclear waste more dangerous than the original nuclear fuel? 2016-11-16T02:55:13.973

132 Why are the harmonics of a piano tone not multiples of the base frequency? 2016-07-17T16:45:32.343

131 Why does a mirror split my laser beam? 2016-03-02T15:01:41.830

128 Why do we not have spin greater than 2? 2011-09-21T13:36:34.750

127 Is $\pi^2 \approx g$ a coincidence? 2016-08-22T02:13:11.797

126 If photons have no mass, how can they have momentum? 2010-12-24T13:17:10.747

125 Why does space expansion not expand matter? 2010-12-21T03:59:29.420

125 If you view the Earth from far enough away can you observe its past? 2011-07-06T15:39:21.670

125 Why are the windows of bridges of ships always inclined? 2017-01-08T20:45:37.587

123 Why can I touch aluminum foil in the oven and not get burned? 2018-02-12T01:11:08.543

121 Why are the wet patches on these floor tiles circular? 2018-03-03T22:04:19.710

119 Is the butterfly effect real? 2016-01-26T14:48:58.647

118 Why don't electrons crash into the nuclei they "orbit"? 2012-01-25T15:04:37.523

116 How can you weigh your own head in an accurate way? 2013-07-12T08:51:59.347

116 Why is the vibration in my wire acting so oddly? 2016-07-09T21:01:48.193

114 Gauge symmetry is not a symmetry? 2011-08-23T02:48:20.713


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