Originally Posted by **avito009** Now we come to relativity. Suppose the earth orbits the sun at the speed of light. |

Which is impossible. What you write below indicates that you're merely thinking of the Earth moving at speeds which are merely close to the speed of light. Let's go with that.

Originally Posted by **avito009** Then its mass should increase. Now when we keep r constant that means the distance between the sun and earth is the same when Earth orbits the Sun. Now mass has increased due to higher speed. But r is constant so since mass has increased the velocity is decreased. So is this another way of proving Relativity? |

First off you're being unclear. First you wrote "Then its mass should increase" which, if speaking about the Earth's relativistic mass, is correct. An increase in speed results in an increase in mass. Then you go on to conclude so since mass has increased the velocity is decreased" which is contradicting what the assumption that you started with. The problem with your assumption is the expression L= mxvxr. This is only an approximation and as such it will only hold when the speed of the object is much less than the speed of light.

The correct expression is

**L** =

**r** x

**p**
where

**p** = m

**v**. In this expression m is a function of v.

Regarding

*So is this another way of proving Relativity?* - No. Relativity cannot be proved. No scientific theory can be proved.