Thanks to
Marty who pointed out that Peter Dunns
example is flawed. If we use the simple equation Ve=SQRT(2gr) with the constants g=274 m/s^2 and r=6.96x10^8 m we get the suns Ve=617.5 km/s. This is about 384 mi/s which is still well below 186,411 mi/s. My bad for not checking the math. (I can see
OS shaking his head right now) First let me present a couple of interesting reads regarding gravity:
I'm not saying I agree with the preceding articles, just that they present interesting views of gravity.
Let me now ask another question. How do we truly know the mass of the earth or the sun? It has been calculated using Kepler's Third Law which is: P^2 = ((4pi^2)/(GM))a^3. Hmmm...seems we are relying on G again. My problem with all of this is that all these equations are based off of a set of localized observations. As stated
here, " The key to proving Kepler’s Laws lay in Newton’s equation for gravitational force, which states that the gravitational force between two bodies is equal to the product of the gravitational constant G". The gravitational constant was originally proposed by Henery Cavendish in 1798 using a
torsion bar expiriment. What is this constant G = 6.67 × 10^-11 N m^2 kg^-2? It's nice for describing behavior, but what generates it? The same question can be asked for vacuum permittivity (e0), what causes this value to be 8.854 X 10^-12? More food for thought.