Expansion vs Gravity

When the universe first started to inflate there were no galaxies, stars, or even atoms, just a hot dense soup of particles and photons. Atoms condensed a few hundred thousand years after the big bang, stars and galaxies within a billion years.

Where there is a large clump of mass such as a galaxy, its gravitational force is stronger than the expansion force due to dark energy. In the vast voids between galaxies, it is not and the space between them widens. Galaxies collide because their local velocity exceeds the speed of expansion (Hubble's constant, about 71 km/sec per megaparsec).

Yup. Terry beat me to it.

All rigth, but there was matter, or energy which became matter later. So, if all of that was everywhere (as homogeneuos universe) the expansion would affect all that matter or energy. In principle there must be something that provoked matter concentrations.



Ok; what I wanted to say it´s that precisely. First galaxies should be very near one to another according to the years of expansion as predicted Hubble. Or they weren´t so near as it´s said.

Immediately after the big bang (think time scales of a trillionth of a trillionith of a trillionith of a second) all existence had the form of energy, not matter. It was way too hot for matter to form for a long time after the big bang.

In fact energy levels or temperatures were so hot that the four forces we experience everywhere today (electromagnetic, gravity, strong and weak nuclear forces) in our relativistic universe (one generally obeying Einstein's laws) according to theory where combined into one force called quantum gravity.

A universe ruled by quantum gravity rather than the four forces has very different rules of physics.

As the Universe expanded it cooled. Certain propers of SuperSymmetry (or SuSy) don't let the quantum gravity exist once average temperatures drop so when energy levels fall much below a stupendous 10 ^ 19 GeV - so the dominant forces of reality start splitting apart - a phase change occurs - and their (the four forces) rules of physics start to dominate the existence of the Universe.

Big Bang



So theory goes big bang -> hyper inflation (spacetime unfolded faster than gravity could propogate to stop it, at least 50,000 times lightspeed) -> at time < 10 ^ -34 seconds after the big bang the universe was the size of a basketball, by then it had cooled sufficiently for the four forces to seperate and relativity - with a constant speed of light, to start governing, but by this stage the Universe was way too big and fast expanding for emerging gravity on the right side of the basketball sized universe to every reach the left side of universe and vice-versa.

The creation event begining with quantum gravity physics left about 70% of the Universe casually disconnected under relativistic physics (gravity nor any other force carrier from one side of the Universe can never reach the other).

Some nice piccys here might help chart what happened

http://particleadventure.org/particleadventure/frameless/chart_print.html

especially



Large version (1.1MB) http://particleadventure.org/particleadventure/frameless/chart_cutouts/universe_original.jpg

Yes, although isn´t clear that Universe had a "seize". Of course if there was an origin from "nothing" it had to have a seize like a basketball or like a nutshell (as said Hawking).

Anyway, I can be wrong but it doesn´t have to do quantum gravity with classical one. Macro and micro worlds have different behaviour.

???

Seize? or Size?

Origin could have been from two membranes in M-Theory with their own 11 dimensional reality combining into a new membrane with its own defining 11 dimensions!

You can be wrong - agreed.

"I can be wrong but it doesn´t have to do quantum gravity with classical one" - try that again in English and I'll respond.

"Macro and micro worlds have different behaviour" - this is the critical challenge marrying quantum and relativistic physics

Sorry, I meant size.



Yes, it´s the only way to reach how things are. I agree too.



Maybe I had to say quantum gravity doesn´t have to do with classical one. Anyway, you understood it; it isn´t necessary you reply. It´s better to let Universe does what it wants. Thanks.

Priamus

The question how are quantum mechanics and relativity linked is probably the major science question of this new century!

Thousands of brilliant reseachers and hundreds of billions of research dollars are going in to find a quantum theory of gravity.

I sense English is not your native tongue, it's hard asking questions in a second or third language - sorry if I was abrupt before. I couldn't ask questions of any depth in a foreign langauge!

Don´t worry; you are right. English isn´t my native tongue; though I understand correctly it´s much more difficult to convey what I think. For that reason it can be sometimes hard. But in this life everything has to be improved.

Well, my native language is spanish (Spain); and I have to improve it as well

Thanks again you´ve been very polite.