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Hi Doc,

Thanks for the insight. Using "your" own numbers. I subtracted the acceleration of gravity (5.92E-3 from the acceleration of the sunlight 6.79E-3 to yield a net positive outward acceleration of 8.7E-4 m/s^2. This makes sense because if it was not true then solar sails would not work and comet tails would not point away from the sun, agreed.

OK, put that acceleration into Newton's constant acceleration equation, x = x0 + v0*t + 0.5*a*t^2, with x=0 and v0=0 and t=1 billion years. You get an outward orbital change of 4.3E29 meters! Your number ends up bigger than mine :)

Argue with me all you want, but the FACTS are:

1 - The Earth orbits around the sun in a vacuum. Orbital mechanics tells us its orbit is constant WITHOUT any external force being applied to it.
2 - Light emitted from the Sun produces an outward force. Comet tails pointing away from the sun and solar sails attest to this.
3 - A billion years is a lot of seconds, then you gotta square it to make it bigger.
4 - Whatever acceleration number you use, will give you a massive change in orbit over a billion years, because a billion years is a lllloooonnnngggg time.

There is no way the Earth's orbit has been constant for a BILLION years because whatever kinetic energy it had at time 0 will increase over time as it absorbs light energy in 1 direction (outward). The solar system is not static because the fusion furnace of the sun is slowly pushing everything away from it. The fact that we do NOT see everything spiraling away from the sun at a high velocity is PROOF that the solar system is not even millions of years old.

F H

I subtracted the acceleration of gravity (5.92E-3 from the acceleration of the sunlight 6.79E-3 to yield a net positive outward acceleration of 8.7E-4 m/s^2.

You'll see from the article that those are the figures for a 1 micron particle. Givining a ratio of aolar accelartaion/sun gravity of 1.17, greater than 1 so particles in a comet tail are swept away from the sun.

For a earth size object the ratio is 1.63 x 10^-14. less than one, so the sun's gravity is able to hold the Earth in a stable orbit. The effect of the solar acceleration is to reduce the gravitational attraction ever so slightly.

Which actully means that the orbit is closer to the sun (maybe by a few millimetres) than it would be if the outward solar aceleration was ignored in calculating from the orbital velocity.