Gravity at its maximum range question.

In summary, the Newtonian gravitational field extends out to infinity in all directions and only goes to zero at infinity. As for space-time eventually flattening out, it will eventually flatten out in isolated systems, known as asymptotically flat space-times. The bending of space and time is what causes gravity to act on objects, and this curvature asymptotically becomes flat as you approach spatial infinity. This means that although gravity has infinite range, space-time does not, as it approaches flatness at infinity.
  • #1
solar71
30
0
Hey guys. I have an unusual question.

Lets say the universe is 100,000,000,000 Light years across. (100 billion I think)

Lets say there are only 2 bodies that have mass in said universe.
One body is at one end of this universe and the other body is at the opposite end.

Do these 2 bodies pull on each other? Does gravity have a finite range?
Or does gravity have infinite range but only gets infinitely weaker with distance?

Does space/time eventually flatten out?

Thanks
 
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  • #2
The Newtonian gravitational field extends out to infinity in all directions and only goes to zero at infinity. As for space-time eventually flattening out, if you have a system consisting of isolated bodies (bodies that are always localized to some fixed region of space) then yes space-time will eventually flatten out (such space-times are called asymptotically flat).
 
  • #3
Ok thanks for your well informed reply. Much appreciated.

One more question. I was under the impression that the bending of space and therefor time is what caused gravity to act on objects. So how is it possible for gravity to have infinite range but space/time not to?

Doesn't space have to be slightly bent for gravity to be present? And if gravity has infinite range doesn't that mean that the bending of space also has infinite range as well? And if so doesn't that mean that time is also slightly bent/stretched as well?

I'm a little confused. Please enlighten me.

Thanks
 
  • #4
Consider for example an isolated stationary star. The space-time curvature produced by the star asymptotically becomes flat meaning it approaches flat space-time as you approach spatial infinity. So in this sense it is exactly like the Newtonian gravitational field which itself approaches zero as you approach spatial infinity. Sorry if that wasn't clear before; I wasn't implying that the Newtonian gravitational field is non-zero everywhere, I was implying that it asymptotically approached zero as you approach spatial infinity.
 
  • #5
for your question! It's a very interesting one to think about.

First, to answer your question, yes, these two bodies would still pull on each other even at such a vast distance. Gravity has an infinite range, meaning that any two objects with mass will exert a gravitational force on each other regardless of distance.

However, as you mentioned, gravity does get weaker with distance. This is due to the inverse square law, which states that the force of gravity between two objects is inversely proportional to the square of the distance between them. This means that as the distance between the two bodies increases, the force of gravity decreases exponentially.

As for whether space/time eventually flattens out, this is a topic of ongoing research and debate in the field of cosmology. Some theories suggest that the expansion of the universe will eventually slow down and reach a steady state, while others propose that the universe will continue to expand indefinitely. The concept of a "flat" universe also has different interpretations in different theories. Overall, there is still much to discover and understand about the nature of space and time in our universe.
 

1. What is the maximum range of gravity?

The maximum range of gravity is infinite. Gravity is a force that extends infinitely, but its strength decreases as distance increases.

2. How is the maximum range of gravity calculated?

The maximum range of gravity can be calculated using the formula R = (2GM)/v2, where R is the maximum range, G is the gravitational constant, M is the mass of the object, and v is the initial velocity.

3. What factors affect the maximum range of gravity?

The maximum range of gravity is affected by the mass and initial velocity of the object, as well as the strength of the gravitational force between the two objects.

4. Can the maximum range of gravity be altered?

No, the maximum range of gravity cannot be altered. It is a fundamental property of the gravitational force and is determined by the mass and distance between two objects.

5. How does the maximum range of gravity relate to escape velocity?

The maximum range of gravity is directly related to escape velocity. If an object achieves escape velocity, it will escape the gravitational pull of another object and continue on an infinite path, essentially reaching the maximum range of gravity.

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