# Aliens haven't contacted us yet because there has not until recently been signs of intelligent life on earth.

#### Eightcrackers

##### Well-known member
Gravity relates to the mass of an object, so its gravitational force projected cannot be infinite.
Why?
Two curves can decay to infinity with one always less than the other. Indeed, one always half of the other, for example.

#### Eightcrackers

##### Well-known member
Fine - two force curves can decay asymptotically towards zero, with one always less than the other.

Finite mass does not connote finite range.

#### cjab

##### Well-known member
Fine - two force curves can decay asymptotically towards zero, with one always less than the other.

Finite mass does not connote finite range.
You'll have to explain what you mean in more detail and how it relates to your gravity point.

#### Eightcrackers

##### Well-known member
You'll have to explain what you mean in more detail and how it relates to your gravity point.
You asserted that a finite mass's gravitational field vanishes after a finite distance - I want to know why this follows.

#### cjab

##### Well-known member
You asserted that a finite mass's gravitational field vanishes after a finite distance - I want to know why this follows.
No, you misunderstood me. I asserted that a finite mass's gravitational field exerts proportionally less force on distant objects of increasing mass. Thus the gravitational pull of the earth's field on the Sun is very weak proportionally, as compared with the gravitational pull of the Sun's field on the earth. However conventionally gravity is measured by taking the mass of both objects into account.

#### Eightcrackers

##### Well-known member
No, you misunderstood me. I asserted that a finite mass's gravitational field exerts proportionally less force on distant objects of increasing mass. Thus the gravitational pull of the earth's field on the Sun is very weak proportionally, as compared with the gravitational pull of the Sun's field on the earth. However conventionally gravity is measured by taking the mass of both objects into account.
Why can't two objects of equal rest mass, accelerate towards each other past the speed of light?

Both objects' relativistic mass would increase at the same rate, and always be equal.

#### cjab

##### Well-known member
Why can't two objects of equal rest mass, accelerate towards each other past the speed of light?

Both objects' relativistic mass would increase at the same rate, and always be equal.