All forces neuralized at big bang, & space expansion

AI Thread Summary
The discussion centers on the expansion of space following the big bang and why gravity did not prevent this expansion. It explains that at the big bang, gravity was uniformly distributed, resulting in a net gravitational effect of zero, which allowed for the expansion of space rather than the movement of particles. The concept introduced is that space itself is increasing, rather than forces pushing matter apart. This leads to further inquiries about the nature of space expansion and its causes, including theories like the decay of a false vacuum and the influence of dark energy. Ultimately, the conversation highlights the unique properties of space and the ongoing mysteries surrounding its expansion.
CosmicVoyager
Messages
164
Reaction score
0
What caused and is causing space to increase or expand?

Greetings,

The answer to a major question has raised another problem...then solution...then questions.

Why didn't gravity keep everything together at the big bang like a black hole? Because *all* of space was filled with matter/energy so gravity pulled equally on everything from all directions. There was no place where gravity was stronger. It is like being at the center of the earth. You are surrounded by matter, but the net effect of gravity is zero. But unlike the earth, at the beginning of the universe the center was everywhere, either because the universe is hypersherical or because it is infinite.

Yay! Problem solved. But wait. This would also be true for all forces. Matter/energy being everywhere would mean every force was pulling equally on everything in all directions, so the net effect of any force was zero. So there was no force to push things apart! So how the heck did the universe expand?

I suddenly realized that the universe was not expanding because a force was pushing matter/energy apart, but because space was increasing! The distance between particles was not increasing because of a force pushing them or because they had velocity, but the distance was increasing because the space between them was increasing! Wow! The particles were not actually moving apart. The space they were in was moving! Epiphany!

This raises other questions...

What does it mean exactly for space to expand?

And what caused (and is causing) space to expand?


Thanks
 
Last edited:
Space news on Phys.org
Hey

When space expands the amount of space between any two points increases.

On the deepest level of reality things are based on the laws, and the laws have given space the property of acting like a fabric, and emptiness at the same time. Think of the universe as like a computer simulation. And in a simulation things can be given the property of behaving in two different ways.

You will probably need to do some research on this one because I don't know everything for sure, but I do know that the expansion of space can be caused by two things. A false vacuum decaying into a true vacuum (which caused inflation), and the cosmological constant (also called dark energy), which is a form of anti gravity.
 
What does it mean exactly for space to expand?

And what caused (and is causing) space to expand?

It is just like you said. The distance between every point in space is always increasing. Not the distance between objects, but the distance between points in space. If you imagined space as the surface of a balloon, then if you blew up the baloon everything on the surface would get further apart but have no velocity relative to the space. As for what caused this, I can't say.
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
Why was the Hubble constant assumed to be decreasing and slowing down (decelerating) the expansion rate of the Universe, while at the same time Dark Energy is presumably accelerating the expansion? And to thicken the plot. recent news from NASA indicates that the Hubble constant is now increasing. Can you clarify this enigma? Also., if the Hubble constant eventually decreases, why is there a lower limit to its value?

Similar threads

Back
Top