According to the current cosmological theories, it's the model that explains the early life of the universe, starting from a rapid expansion of hot and dense matter.
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1answer
145 views
Current string-theory version of Big Bang
I always wondered what the description of Big Bang would be like in string theory.
How is it different from QFT version of Big Bang?
Thanks.
3
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2answers
180 views
How is it possible to come to a conclusion that Universe is a result of the Big Bang while we aren't able to observe the entire Universe?
-I'm not a religious person so this is not a denial. I'm just trying to understand the most fundamental topic about Universe.
-I know the Big Bang cosmological model is not a law but it's a theory.
...
3
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0answers
74 views
Conservation of Energy in the Universe [duplicate]
Possible Duplicate:
Is energy really conserved?
Why can’t energy be created or destroyed?
One of the laws of the universe that dazzles me the most is the law of conservation of energy. I ...
2
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4answers
358 views
Big Bang snuffed by a black hole?
Wasn't the density of the universe at the moment after the Big Bang so great as to create a black hole? If the answer is that the universe/space-time can expand anyway what does it imply about what ...
2
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2answers
177 views
Was Planck's constant $h$ the same when the Big Bang happened as it is today?
Was Planck's constant $h$ the same when the Big Bang happened as it is today?
Planck's constant :
$$h= 6.626068 × 10^{-34}\, m^2 kg / s,$$
$$E=n.h.\nu,$$
$$\epsilon=h.\nu$$
2
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1answer
51 views
Could there be a sort of “Molecular Destiny”?
Let's say we start with the Big Bang. Every bit of matter started from this event. Therefore, given EVERY variable (every particle, movements of particles, weights, times, etc) and an INFINITE amount ...
2
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1answer
65 views
How fast did hydrogen atoms travel when they were first formed in the early universe?
I can't seem to find any data on this, is it a known value?
2
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1answer
123 views
Total momentum of the Universe
What is the total momentum of the whole Universe in reference to the point in space where the Big Bang took place?
According to my reasoning (and a bit elementary knowledge) it should be exactly ...
2
votes
2answers
426 views
Big bang and time
I heard Carl Sagan talking about the Universe 15 Billion years ago, and the Big Bang. He made the statement that it was the biggest explosion of all time (at first I thought this a subtle pun). This ...
2
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1answer
210 views
How is it possible that we see light from shortly after the big bang?
How can astronomers see light from shortly after the big bang? How did we get "here" before the light that emanated from our "creation"?
2
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1answer
1k views
What did Hawking mean? 'Time started at the big bang'. Book suggestions please [closed]
After writing down this question, I have come to realize that. What I really want is reading materials on the questions below.
Before the big bang there was no such thing as 'time' (Steven Hawking on ...
2
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1answer
80 views
What was ticking just after the Big Bang?
When reading about the Big Bang, I see phrases like 3 trillionths of a second after... So, what was ticking to give a time scale like this? We define time now in terms of atomic oscillations, but ...
2
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1answer
100 views
Reference request for low entropy big bang
There is a somewhat widely accepted argument that the second law of thermodynamics exists because the universe began in a low-entropy state. I'm writing a paper that mentions this (and must be ...
2
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1answer
36 views
Why do we need the concept of dark energy to explain the expansion of the universe?
Why can't the expansion of the universe be thought as the Big Bang itself still in progress? Why do we need to introduce dark energy? The Big Bang was powerful, and that explosion itself could still ...
2
votes
3answers
232 views
Why every galaxy is moving away from every other galaxy on astronomical scale? because of an explosion or because of creation of space?
Why galaxies move away from each other in general on the astronomical scale?
Which answer is correct of the following?
It is because of the big bang theory, everything is just moving away from ...
2
votes
2answers
186 views
Frame of reference and big bang
I have read Brief History of Time in which he has wonderfully described the formation of universe. What is the frame of reference from which we are viewing the big bang? What is the frame of reference ...
2
votes
1answer
14 views
Does the expansion of the universe soon after the Big Bang affect the amount of time that light takes to reach us?
If faster than light travel is impossible, how is it that light emitted from matter so close together in the time soon after the Big Bang is only now just reaching us? I would assume that there would ...
2
votes
1answer
195 views
The relation between the speed of light and the Big Bang Theory
I would like to know how much of the Big Bang theory is dependent on the constancy of the speed of light.
P.S.: It might be guessed that I am asking this because of the recent CERN news.
Yes, of ...
2
votes
0answers
55 views
How can I read density fluctuation from microwaves?
The Cosmic Microwave Background Radiation shows temperature differences. The red and yellow areas are warmer. The green and blue areas are cooler.
For example consider this picture of CMBR ...
2
votes
4answers
283 views
How was the universe created?
I do not know much beyond high school Physics. Thus, I am asking this question from almost layman's perspective:
What, as per the best of our existing knowledge and widely accepted among the ...
2
votes
9answers
676 views
understanding time: Is time simply the rate change?
Is time simply the rate of change?
If this is the case and time was created during the big bang would it be the case that the closer you get to the start of the big bang the "slower" things change ...
2
votes
3answers
351 views
Does (it make sense to say that ) the universe has a center?
I was reading this page:
http://www.guardian.co.uk/science/2011/oct/23/brian-cox-jeff-forshaw-answers
and I found this sentence by Brian Cox:
That seems to imply that everything is flying away ...
1
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2answers
225 views
Primordial Black Hole Detection
There's ample direct evidence for the existence of galactic and stellar mass black holes. However, there is no such direct evidence of primordial black holes, those formed after the Big Bang. A recent ...
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3answers
143 views
Can space expand with unlimited speed?
At the beginning, right after the Big Bang, the universe was the size of a coin. One millionth of a second after the universe was the size of the Solar System (acording to ...
1
vote
1answer
371 views
How to calculate the density of relic neutrinos?
May be not neutrinos, but antineutrinos? Or both types?
In the last case, why they didn't annihilate and what is the ratio of relic neutrinos to relic antineutrinos? Is that ratio somehow related to ...
1
vote
2answers
164 views
Excluding big bang itself, does spacetime have a boundary?
My understanding of big bang cosmology and General Relativity is that both matter and spacetime emerged together (I'm not considering time zero where there was a singularity).
Does this mean that ...
1
vote
1answer
200 views
Is it possible that the Big Bang was caused by virtual particle creation?
As far as I understand, it is understood that throughout the universe there exists, what is known as, a quantum field from which, due to its fluctuations, temporary (pairs of) virtual particles ...
1
vote
1answer
228 views
Superluminal expansion of the early universe how is this possible?
Is this a postulate? I get the expansion of the universe, the addition of discrete bits of space time between me and a distant galaxy, until very distant parts of the universe are moving relative to ...
1
vote
1answer
336 views
Universe Expansion as an absolute time reference
Why we call "constant" to the Hubble constant?,
if the universe were really expanding then the Hubble "constant" should change, being variable, smaller and smaller..with "time".
Other example/view ...
1
vote
1answer
271 views
Branes Collision -> Big Bang
Imagine universe occurred when two parallel branes collided, Momentum of Branes converted to big bang kinetic energy after Collision. Thus, high-energy quanta are high-Vibrating strings.
what ...
1
vote
2answers
198 views
How is Big Bang related to theory of relativity?
I'm not someone with good scientific knowledge, so if my question are weird, correct me.
I was reading about big bang and I came by the theory of relativity. Can someone explain the relation between ...
1
vote
1answer
209 views
spacetime expansion and universe expansion?
First of all, does the expansion of spacetime solely cause the expansion of universe?
Secondly, if spacetime is the sole cause, do objects(matter with mass) themselves expand?
Thirdly, by spacetime ...
1
vote
1answer
430 views
Has Cosmological Natural Selection been disproved?
I've been reading Lee Smolin's Life of the Cosmos.
Great book and it makes a lot of sense that the conditions in black holes are the same as conditions at the big bang.
Question is, has his theory ...
1
vote
1answer
60 views
Assuming space is infinite can our observable universe be an island amongst an archipelego?
According to recent measurements our observable universe is roughly 93 billion light years in diameter; also it appears (according to WMAP measurements) that spacetime is flat.
Supposing space is ...
1
vote
2answers
123 views
What's the evidence supporting 1 singular Big Bang? [duplicate]
Possible Duplicate:
What has been proved about the big bang, and what has not?
I love to dabble with science, I'm by no means a scolar in this field. One thing that haven't seen proven yet ...
1
vote
4answers
159 views
Can cosmic inflation be explained by matter antimatter reactions?
The big bang theory proposes that equal amounts of matter and antimatter were created in the beginning. Shortly afterwards most of it annihilated. Could that have produced enough energy to drive ...
1
vote
1answer
2k views
Negative and positive energy and Hawking [closed]
I don't have any physics background (except the material we did in high school-long time ago).
I was watching a documentary with Stephen Hawking about whether God created the Universe and I could not ...
1
vote
1answer
1k views
List of theories supporting origin of universe [closed]
Big Bang theory is widely accepted theory when it comes to origin of universe. What other really compelling theories are out there explaining/supporting the origin of universe. I know many people ...
1
vote
1answer
77 views
In the big crunch theory, when the big crunch singularity forms, can the resulting black hole decay through hawking's radiation?
I've been pondering about this and I couldn't really find the answer for this. The big crunch theory postulates that the universe will eventually stop expanding and reverse back in on its self into a ...
1
vote
1answer
104 views
Are there still Big Bang Gravitational effects
If all matter was concentrated at one point before the big bang, I assume that the gravity was at a huge scale. For a long time many believed that the universe would eventually collapse back upon ...
1
vote
1answer
88 views
Cosmic Background Radiation: How did planets form before the CBR could reach us?
I've understood that the Cosmic Background Radiation(CBR) is an electromagnetic wave that originated from the big bang. However, we now live on a planet which that is also originating from the big ...
1
vote
3answers
138 views
Energy and Matter
I was watching a show about the big bang theory. They were saying that in the beginning all that existed was energy. After the big bang that energy transformed into matter which then started forming ...
1
vote
1answer
302 views
How did the energy/entropy/volume/pressure/temperature relationship exist at the Big Bang and how did it evolve thereafter?
According to the current Big Bang with inflation cosmological model?
I was under the mistaken impression that there was very low volume, very high temperature/pressure, very low entropy and the Big ...
1
vote
1answer
154 views
Are there any theories or suggestions for how the multiverse came into existence?
I've just seen a documentary about the multiverse. This provides an explanation for where the big bang came from. But it leaves me wondering: how did the multiverse come into existence?
Because this ...
1
vote
2answers
190 views
How to concile flat spacetime and big bang?
After reading How do we resolve a flat spacetime and the cosmological principle? I still remain perplex.
Please excuse my ignorance and try explaining to me :
I thought that basically, when we ...
1
vote
1answer
63 views
How do we know space is expanding when we are part of space? [duplicate]
From what I understand space itself is expanding, and the Big Bang attempts to describe this expansion at the very early stages of the universe.
This is usually described in a visual way as 2 dots on ...
1
vote
0answers
43 views
Is the speed of light the ultimate speed limit? [duplicate]
As we all know nothing can go faster than the speed of light as mentioned by most of our pioneer's in physics. But as I was listening to one of the statements of Sir. Stephen Hawkins he stated that at ...
1
vote
0answers
183 views
Curiosity episode with Stephen Hawking. The Big-Bang
In an episode of Discovery's Curiosity with host Stephen Hawking, he claims the Big Bang event can be explained from physics alone, and does not require the intervention of a creator.
1) His ...
1
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0answers
47 views
What evidence is there for the Big Bang Theory? [duplicate]
Possible Duplicate:
What has been proved about the big bang, and what has not?
I know the expansion of the universe is the most compelling but what else makes it so well liked and believed. ...
1
vote
2answers
63 views
proportion of dark matter/energy to other matters/energy at the beginning of the universe
How will the proportion of dark matter/energy to other matters/energy be like at the momenets after the beginning of the universe (standard Big Bang model)?
