[SOLVED] big bang doubt, what made them decelarate

[achaleus]

Hello all, It was said that whole thing originates from big bang.
This whole universe,galaxies,gravitational waves all came from a very very small densely packed with infinite volume particle (what so ever I don't know what it is ) exploded...

my question is as there is no external force acting on it, according to law of inertia

1) what made it exploded.
2) If it is exploded with certain acceleration, what made them to decelerate(as there is no external force as such)

had lots of ques.. where can I find my sol...

thanks

 

[BradtheRad]

Gravitational attraction causes the deceleration. Astrophysicists have debated whether the universe will slow its expansion and collapse eventually. Latest evidence says it will continue to expand forever.

This is similar to the concept of escape velocity. At Earth's surface it is 7 miles per second. For the universe it could have been a large percentage of the speed of light.

As for your first question...
We humans cannot fathom why the initial proto-particle exploded when it did, or where it came from, or what held it together before it did explode, etc. And believing in an intelligent First Cause does not make the questions less fascinating.

 

[123jack]

Assuming of course such a "proto-particle" existed in the first place.
As I understand it that is just an extrapolation with no evidence found yet so
maybe is didnt start out as small as that in the first place - which would have all manner
of consequences I expect.

I'm of the opinion the acceleration at the edges is caused by gravity and nothing else.
(A big hulking mass we have no knowledge of at all) - its just an opinion of course.
But that makes far more sense to me than the highly convoluted alternatives.