The Cavendish experiment is cool, but seems complicated to experimentally perform. What is a simple way to recreate the experiment?
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$\begingroup$ Related: physics.stackexchange.com/q/356/2451 $\endgroup$– Qmechanic ♦Commented Sep 17, 2014 at 16:49
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1$\begingroup$ hey, it's not big $G$ on the cheap, but if you want to see how physicists perform the Cavendish experiment today, check out the U Washington apparatus, including this time-lapse video of it in operation. $\endgroup$– robert bristow-johnsonCommented Sep 17, 2014 at 17:47
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1$\begingroup$ say, i found a short physics course .pdf doc that makes an interesting reference to C. L. Stong, "How to repeat Cavendish's experiment for determining the constant of gravity", The Amateur Scientist column in Scientific American, September 1963, p267. good luck finding a copy. $\endgroup$– robert bristow-johnsonCommented Sep 17, 2014 at 18:00
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2$\begingroup$ A Cavendish experiment is rather easy to perform these days, since you can measure tiny movements with capacitive sensors or a simple optical interferometer with very high accuracy. This leaves you with the usual problems of working on a very solid table anchored to a large foundation (concrete mix is dirt cheap!), getting a bunch of lead balls and finding a torsion fiber that does not suffer from non-linearities and memory effects, but other people have done the hard work for you, see e.g. physics.uci.edu/gravity/papers/icifuasPaper.pdf. Good luck! $\endgroup$– CuriousOneCommented Sep 17, 2014 at 20:21
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1$\begingroup$ @Jon they say so themselves: “some of them wished we could have calibrated the torsion balance”. Also no attempt to compare the observed acceleration to the expected. 10 minutes to travel 6”? What mass would you need? Easy to compute… orders of magnitude off. $\endgroup$– FlorisCommented Oct 16, 2021 at 18:18
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1 Answer
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The way Cavendish did it would seem to be simplest - it can be done with 18th Century technology.
In practice its very difficult to do in a lab, alternately it is a very good way to demonstrate the resonant properties of concrete lab buildings.
If you wanted to try it for yourself then a garden shed, with an insulated inner room/box built of plywood and styrofoam and a vibration proof table made from stacks of inner tubes and paving slabs, and a telescope+webcam so you can keep it completely sealed. Seems plausible.
answered Sep 17, 2014 at 16:43
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1$\begingroup$ @WetSavannaAnimalakaRodVance, sorry 18th Century, it's standard history shorthand at least in British English. The experiment was done in 1799 $\endgroup$ Commented Dec 30, 2014 at 15:51