Quote (card_sultan @ Jun 9 2016 10:47am)
According to the Heliocentric model - aren't we constantly rotating around the constant gravity of the sun and constantly traveling at 66,600 miles per hour? Are you suggesting that if the Sun's constant force of Gravity - the earth should be accelerating its orbit? So like next year it will be orbiting at a billion miles an hour and in ten years it should be a trillion miles an hour?
Here's a question for you, if all objects have gravity and if the Gravity on the moon is less than the earth because of its size (As was comically shown by Nasa) and the the Sun is like 1000x bigger - why aren't we sucked into the sun? I mean this supposed gravity is constantly keeping pluto in orbit too - that's a lot of gravity it must have.
We are constantly accelerating due to the sun, but in the direction of the sun, not in the direction of our orbit. Here's a crude diagram I made in paint.
We have forward momentum which tries to carry us away from the Sun. However, the force of gravity from the sun tries to pull us in. The net result is that Earth follows a roughly circular. If there was no gravity we would fly away from the Sun due to our forward momentum.
The Sun accelerates us in the direction of the Sun at all times, so at every point the acceleration is at a 90 degree angle to our forward momentum, and the path is circular.
(it's actually an elipse, but you have to know more calculus than I do to derive that)