Cavendish experiment

[[File:Cavendish Experiment.png|thumb|right|165px|A schematic of the original Cavendish experiment]]
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The '''Cavendish experiment''' was the first experiment that measured the force of [[gravity]] between [[Mass (physics)|masses]] in laboratory conditions, and the first one to produce an accurate value for the gravitational constant. The experiment was performed by {{wpl|Henry_Cavendish|Henry Cavendish}} in 1797-1798.

==The experiment==

The basic idea of the Cavendish experiment was to suspend two lead 0.73kg spheres attached to a 6ft (1.8m) wooden rod, that was suspended from a wire that resisted torsion. Next to this object, two 348 pound (158 kg) lead spheres suspended on a separate rod. As the larger balls were moved in close proximity of the smaller ones, they would attract each other. By measuring the angle of the rod, and by knowing the twisting force for that angle, Cavendish determined the gravitational force between the objects. For more details, see {{wpl|Cavendish_experiment#The_experiment|Wikipedia.}}

==Rejection by Flat Earthers==
{{main|Flat Earth}}
This experiment is a sensitive matter for [[Flat Earth]]ers, whose ideas are threatened by it. For example, [https://youtu.be/J7RwAcL4Iq0?si=IDeVXlge4vwRzN-c&t=9021 Eric Dubay] misrepresents, even blatantly lies about the experiment, as part of defending his worldview.

Dubay's first claim is, that the experiment "has been widely criticized by the scientific community" which straight up contradicts with what he blurts out a bit later, that "the experiment went down in history as a great success".<ref group=note>This is intentional. [[Cult]]s like flat Earth contradict themselves all the time as a litmus test to ensure the members are willing to accept anything the cult leaders say. It's not about truth, it's about loyalty to the leader.</ref> The truth is, the experiment was an amazing achievement, as said [https://youtu.be/Uz4tjI0cla0?si=PSkWY7tOxL5bF35U&t=83 here] by Richard Feynman. Dubay lies on:

'''"No one has ever been able to relpicate the Cavendish experiment in over 200 years"'''

YouTube has tons of amateurs doing it but that would be too easy to dismiss. Here's experiments done with proper scientific instruments:

{{#ev:youtube|https://www.youtube.com/watch?v=70-_GBymrck|||||start=440}}

[https://asd.gsfc.nasa.gov/Stephen.Merkowitz/G/Big_G.html Here] [https://sciencedemonstrations.fas.harvard.edu/presentations/cavendish-experiment are] [https://www.youtube.com/watch?v=mJXHX08_M1c some] [https://www.youtube.com/watch?v=GEz1piaJCXw more] [https://www.youtube.com/watch?v=4DlyZL436hE replications], [https://youtu.be/sdJTaw68hPo?si=Atbg1VZKZ0zMiP0y&t=162 JFC!] [https://www.youtube.com/watch?v=wtT_2zZcYuE There's] [https://www.youtube.com/watch?v=fw9n1qQYAfQ too] [https://www.youtube.com/watch?v=pFg6qCQ-QC8 many] [https://www.youtube.com/watch?v=eA--AOM0D-k of] [https://www.youtube.com/watch?v=rmn_ecxky3U them!] [https://www.youtube.com/watch?v=O1iquvRj61U AAAAAA!]

"'''But you can't interact with the system without causing oscillation!'''"

Next Dubay claims that it's not possible to interact with the system without interfering it, and that Cavendish himself had to deal with annoying oscillation. The oscillating movement is obviously visible in the replication, but it slowly dies out. The fact there is oscillation is however required to calculate G (which is what the experiment was about).

'''But the experiment does not control for electromagnetism!'''

Dubay then complains about lack of control experiment because electromagnetism could have been responsible. What he failed to realize, is that lead is {{wpl|Diamagnetism|diamagnetic|,}} i.e. it can not be magnetized, because it's 82 electrons are in the configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p², i.e., it doesn't have unpaired electrons that would allow it to be magnetized.

"'''But the experiment does not control for static electricity!'''"

Dubay then states that because "the balls might be magnetic, thus they might attract each other via static electricity", and especially, that "this can not be controlled for". However, since lead conducts electricity, simply grounding the balls, or making them touch will balance out the electric charge between them. Static electricity has been demonstrated and controlled for a long time, as can be seen in [https://youtu.be/VYf-Glwtr68?si=fEAx9_OUYfC18wlc&t=306 this] old film, that uses a metal mesh to block the static electricity between a water bottle and sand bag used in place of the lead balls. (The video provides much more debunking wrt static electricity being the cause, so watch all the way to the end). Modern research grade systems are grounded. So, it's actually trivial to control.

==See also==
*[[Gravity]]
*[[Mass (physics)]]

==Notes==
{{reflist|group=note}}

==References==
{{reflist|2|80%}}

[[Category:Silly "Earth" theories]]
[[Category:Flat Earth]]
[[Category:Physics]]

Categories: Silly "Earth" theories, Flat Earth, Physics