Tuesday, April 7, 2009

Space-time, gravity, speedily expanding universe

Einstein's theory states gravity is not a force, but bending of space-time around massive objects. The more massive the object, the more bend, and hence more gravity. This is a proven theory.

Now, lets put this in the context of big bang and expanding universe.

We have mass-energy and space-time taking birth at big bang. Some say this mass-energy comes from vacuum and negative vaccum pressure is causing accelerated expansion of the universe. Others stick to string theory for cause of big bang. Further, on blaming some "dark energy" for expanding universe.

Lets get down to basics and do this thought experiment. To explain expanding universe, it says "acclerating" expansion of universe. In simple language I understand it is space with matter is expanding in a lesser time. Or as normally seen in normal time, space with matter is expanding faster. Its like space is stretching with time contracting.

If gravity is bending of space-time, what could be the explanation for the expansion of universe with increasing space in deceasing time, in terms of bending space-time??



Fine!

Let's continue with another, but little bit skewed explanation in this thought experiment.

The basis for proposing the big bang theory and further the accelerated expansion of the present universe is the observation of this expansion in all directions from the time of Hubble to the present time of WMAP satellite observation.

Now basically the WMAP has clearly detected microwave background radiation to explain the big bang theory. How does this clearly explain that there was only one big bang?

Why couldn't there be multiple big bangs (from possible multiple naked singularities that existed prior to these big bangs) to explain the scattering of the matter in the universe over vast distances of more than 100 billion light years with most matter being not more than 14 billion years old.

I know, I'm taking liberties here of doing away with cosmic inflation theory and may be hinting at a scenario of multiple big bangs and hinting at big crunches (which must've led to multiple naked singularities) before them.

Even the present actual scenario seems that only the black holes will be the last remnants of the present universe, before they're supposed to either first gulp each other and/or evaporate on their own individually (by hawking's radiation) in a long time. Question then arises that why couldn't these be leading to the scenario similar to multiple naked singularities that might have existed prior to multiple big bangs. But that's a lot of hypothesis.

One clear observation to undo the theory of multiple big bangs is that, if there were multiple big bangs, at least some matter on the border of 2 big bangs on explosion should come nearer. Actual observation is that every object in the universe is moving away from each other.

First somebody clear this to me: How does the evidence of microwave background radiation detected by WMAP rule out multiple big bangs? Can anybody give me layman's proof for this? (I'm not good at understanding explanations using complex mathematic equations)

I got A Answer:

You have it backwards. The warping of Space/Time is not caused by Gravity. Gravitational attraction is the effect of this warping, which is caused by Mass.

Read section #4 in the following...
http://helios.gsfc.nasa.gov/qa_gp_gr.html



Are There Any Other Links Which Explains My Question in Better Way??

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