Ball's Out Physics : Part 4 of 11 - The Gravitational Constant

"Excellent short video on Gravity and Relativity: https://www.youtube.com/watch?v=W_axe...

In this episode we look at how the equation for gravity was developed and the experiment that was allegedly used to determine the Gravitational Constant, big G. It appears that the original experiment is very difficult to reproduce and that is very questionable since it was performed over 200 years ago.

Link to the Human Universe: Episode 4 Preview, mentioned in this episode: https://www.youtube.com/watch?v=E43-C...

Cavendish Method Demonstration: https://www.youtube.com/watch?v=4JGgY...

Physics professor talking about Cavendish and the Torsion Balance (3:00): https://www.youtube.com/watch?v=2PdiU...

Miles Mathis' excellent argument against the Torsion Balance experiments: http://milesmathis.com/caven.html

Conclusion Summary:
I am 50/50 on whether the value of big G has ever been determined through experiment, let alone if Cavendish successfully performed it. After hours of research, I have not been able to find any video evidence of a simple torsion balance actually working. All I can find are articles that show pictures of devices and claim that they work. Many people are also claiming that they do not work. So it is possible that Cavendish originally estimated the average density and mass of Earth, and now his successors are keeping the illusion going by claiming that the value is changing through new experiments that may not be real. However, what is really important about this episode is understanding F=MA and how the mass of the Earth is calculated by setting the gravity equation equal to the weight equation. This sets the stage for episode 3, where we will look at the relationship between the centripetal force equation and gravity: https://www.youtube.com/watch?v=Eh9Yu"