The Small Particle That Started The Big Bang

In summary, the conversation discusses the origins of the universe and the role of the Big Bang theory in explaining it. It also touches on the concept of spacetime and its relationship to particles. However, due to the limitations of our current understanding of physics, we are unable to fully explain the beginnings of the universe and can only make educated guesses based on scientific laws and theories.
  • #36
Pattonias said:
But isn't this pure theory, can you give me reference, because their must be something that I need to read - instead of picking up this idea one piece at a time?

What would indicate that the edge of the universe loops around to the other side, and what difference would it make if it did?
The difference it makes is that it shows that there is no "place outside of the universe into which the universe is growing".

Sorry, I don't have any references available right now.
 
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  • #37
DaveC426913 said:
The difference it makes is that it shows that there is no "place outside of the universe into which the universe is growing".

You have to put that bubble somewhere. I, on the other hand, think that flat universe solves that issue very nicely.
 
  • #38
Does our Universe give some sign that there are no other universes that exist (somewhere else) that could have originated by a big bang or other matter generating event?
 
  • #39
We can only speculate about other universes. No physical evidence exists.
 
  • #40
Thank you S. Vasojevic for the reference, it is making this a little easier to understand.

Are there particles or masses in the Universe that are more or less sensitive to gravity than others?

For instance, I have heard it said that light has no mass, yet it can be trapped by a black hole. Is it possible that it is only sensitive to extreme gravity?
For instance, the slight bend of a beam of light as it passes near a star. Is it possible that light is actually unaffected by gravity below a certain strength or that gravity below a certain strength has no effect on certain particles at all?

Does the intensity of a gravity actually affect the speed at which it reaches out to an object?
 
  • #42
Pattonias said:
Are there particles or masses in the Universe that are more or less sensitive to gravity than others?

No. Gravity affects everything.

For instance, I have heard it said that light has no mass, yet it can be trapped by a black hole. Is it possible that it is only sensitive to extreme gravity?
For instance, the slight bend of a beam of light as it passes near a star. Is it possible that light is actually unaffected by gravity below a certain strength or that gravity below a certain strength has no effect on certain particles at all?

Light is affected by gravity. There is no treshold of sensitivity. Smaller the potentials -smaller the result.

Does the intensity of a gravity actually affect the speed at which it reaches out to an object?

Not at all. Gravity propagates at C, same speed as light do.
 
  • #43
S.Vasojevic said:
Not at all. Gravity propagates at C, same speed as light do.
Well...

Gravity does not travel at all. Gravity is a field, which means it is always everywhere, all the time. Changes in gravity do, however, propogate at the speed of light.
 
  • #44
DaveC426913 said:
Well...

Gravity does not travel at all. Gravity is a field, which means it is always everywhere, all the time. Changes in gravity do, however, propogate at the speed of light.

That makes sense, I have seen gravity described as a fabric and the fluctuations in gravity around a black hole as ripples in this fabric. (Feel free to disect this statement, but I was putting no weight into it :wink: )
 
  • #45
S.Vasojevic said:
DaveC426913 said:
The difference it makes is that it shows that there is no "place outside of the universe into which the universe is growing".
You have to put that bubble somewhere.
No, you don't.
 
  • #46
Official WMAP site:
WMAP nailed down the curvature of space to within 1% of "flat" Euclidean, improving on the precision of previous award-winning measurements by over an order of magnitude


DaveC426913 said:
No, you don't.

That doesn't even matter. Question is, is it curved or is it flat, and we will probably never know. If we could measure its curvature we can exclude it being flat, but not the other way around. Even when some future measurement comes out saying "flat-Euclidean within 0.1%", we could always say that curvature is so slight that it lays within error margin.
It is again Nature playing tricks on ourselves. You want to know do you live in finite or infinite universe? You will have to try much harder than that.
 
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