A falling universe

cottonkat5

I'm sure this will sound like quite a childish question, but Is it possible that there are high amounts of gravity throughout the whole universe (probably not the right wording), and that all celestial bodies are falling in "nothing" at the same rate of speed.

mathman

The universe is expanding and the expansion is accelerating, opposite of the effect that you are asking about.

Drakkith

There is no reason to believe that everything in the universe is in free fall.

Vincent Amato

After reading Koestler's The Sleepwalkers, and not being a mathematician, the construct that seemed to best fill the requirements of orbiting bodies and gravity was a universe in which everything was in free fall relative to its location. That is to say that our star, the Sun, is in free fall as part of the larger galaxy, taking along with it Earth and the other planets. As there is no center to the universe, it would seem silly to say falling "down," rather everything is in free fall regardless of direction. As larger objects fall, they draw in smaller objects. I won't go on--although I could.

zhermes

Quote by cottonkat5

I'm sure this will sound like quite a childish question, but Is it possible that there are high amounts of gravity throughout the whole universe (probably not the right wording), and that all celestial bodies are falling in "nothing" at the same rate of speed.

There seem to be two aspects of your question:
1) 'free fall' / 'gravity' --- this doesn't make sense. The universe is effectively defined as the region of spacetime that is interacting... thus anything causing gravity is necessarily 'in' the universe. Additionally, whats almost always important is the difference in gravity between regions---thus if there were a 'constant' gravitational field the entire universe 'felt' --- it wouldn't have any effect (for the most part).

2) It sounds like you're asking if ever object in the universe is moving in some direction, at the same speed. In relativity there is no concept of absolute velocity (speed). Therefore if everything were moving at the same relative velocity, we would just call that 'zero velocity'.

Chronos

Agreed. All bodies in orbit are in free fall. The earth falls around the sun, but, is moving too fast to fall into it [which is good]. A satellite launched into orbit free falls around the earth, but, is going too fast to crash into it. All courtesy of gravity. The only direction gravity knows is towards the largest nearby center of mass.

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cottonkat5	A falling universe Tweet I'm sure this will sound like quite a childish question, but Is it possible that there are high amounts of gravity throughout the whole universe (probably not the right wording), and that all celestial bodies are falling in "nothing" at the same rate of speed.

mathman Recognitions: Science Advisor	The universe is expanding and the expansion is accelerating, opposite of the effect that you are asking about.

Drakkith Recognitions: Gold Member	There is no reason to believe that everything in the universe is in free fall.

Chronos Recognitions: Gold Member Science Advisor	Agreed. All bodies in orbit are in free fall. The earth falls around the sun, but, is moving too fast to fall into it [which is good]. A satellite launched into orbit free falls around the earth, but, is going too fast to crash into it. All courtesy of gravity. The only direction gravity knows is towards the largest nearby center of mass.