Tagged Questions
1
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1answer
58 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
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2answers
161 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 ...
0
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1answer
103 views
Did space and time exist before the Big Bang? [duplicate]
I accept the Big Bang theory. What I can't understand is how there can be a where or when to the Big Bang if space time did not exist prior to it. Did space and time exist prior to the Big Bang?
2
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1answer
64 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?
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1answer
68 views
Which was first, energy or matter in the creation of our universe?
Was it the Big Bang or was it something else that gives us our universe in its present condition?
Did it all begin with just pure energy that eventually evolved into simple atoms of matter, that ...
1
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3answers
142 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
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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 ...
0
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1answer
95 views
Particles entangled after the big bang
Is that true that the big bang caused the quantum entanglement of all the particles of the universe so every particle is entangled to each other particle of the universe?
1
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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 ...
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 ...
0
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0answers
105 views
Did force of gravity cause macroevolution?
Did big bang create gravity?
What role gravity is assumed to have played in the formation (starting from the big bang) of large structures of our universe and what other important physical mechanisms ...
-2
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2answers
86 views
How exactly, or whats the process, rather, of energy changing into matter?
$E=mc^2$ this is the equation by Einstein claiming energy can change from energy to mass. this would happened at the big bang I assume, when electrons and protons were made to create hydrogen and some ...
2
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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 ...
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1answer
69 views
How to understand movement in expanding universe?
I know that universe is expanding equally between every pair of points but it was a single point in it's very past... so I was wondering if we could locate this center point of universe. Now I know ...
1
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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 ...
3
votes
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 ...
1
vote
1answer
199 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 ...
0
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0answers
35 views
What's a compact scientific answer to question “(Why there is) / (what is before) the Big Bang?” [duplicate]
Possible Duplicate:
Did spacetime start with the Big bang?
on causality and The Big Bang Theory
Before the Big Bang
What's a compact scientific answer to question "(Why there is) / ...
4
votes
3answers
220 views
Do new universes form on the other side of black holes?
I have four questions about black holes and universe formations.
Do new universes form on the other side of black holes?
Was our own universe formed by this process?
Was our big bang a black hole ...
1
vote
1answer
268 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 ...
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.
...
2
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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 ...
0
votes
0answers
50 views
Energy can't be created or destoryed? [duplicate]
Possible Duplicate:
Conservation law of energy and Big Bang?
If energy can't be created or destroyed then how did the big bang create energy? and if energy can't be created then does that ...
4
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3answers
191 views
Is the cosmic horizon related to the Big Bang event?
The Universe expands according to the Hubble's law: velocity is proportional to distance.
There must be some distance, therefore, at which the velocity reaches the speed of light. This defines the ...
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9answers
740 views
Can a universe emerge from nothing?
If the Universe is flat and the total energy of the universe can be zero (we don't know if it is, but many theorists support the idea, i.e. at BB initial conditions:
t = 0, V = 0, E = 0) then is it ...
5
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3answers
207 views
Why the red-shift of distant galaxies is considered to be the effect of expanding spacetime?
Why it's not explained just by Doppler redshift caused by faster movement of those galaxies billions of years ago when that light was emitted?
Would the speeds of the galaxies necessary for Doppler ...
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3answers
118 views
Accelerating expansion of the universe and cyclic model
So I've heard that recent observations indicated that the rate of expansion of the universe is accelerating. Does this indicate that the universe can NOT be cyclical, with an infinite series of big ...
2
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1answer
122 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 ...
4
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3answers
124 views
If the universe started again with exactly the same conditions… would it be the same?
Sorry if this is a basic question but I can't find anywhere to ask else to ask it:
If the universe was created again and exactly the same conditions where in place at the beginning, would everything ...
0
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1answer
52 views
Can anything come out from the big bang?
If any configuration of matter can fall into a black hole and hit the singularity, and ditto for the big crunch, and there is time reversal CPT invariance, does it mean anything can pop out of the ...
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 :
$$h= 6.626068 × 10^{-34}\, m^2 kg / s,$$
$$E=n.h.\nu,$$
$$\epsilon=h.\nu$$
3
votes
2answers
118 views
Shouldn't LHC have used $p\bar{p}$ collisions, instead of $pp$ collisions, to study baryogenesis?
Baryogenesis is the physical process(es) that produced baryon antibaryon asymmetry in the early universe. That means, the laws that governed the bigbang was baryon-antibaryon symmetric.
On the other ...
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1answer
99 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 ...
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4answers
158 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 ...
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11answers
493 views
Are there any theories that explain the very beginning of absolutely everything? [closed]
Of course there's the theory of The Big Bang, and there are theories on what caused The Big Bang, but what was the cause of the very first thing that ever happened? What started every
I also won't ...
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)?
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1answer
46 views
observation and implied time since creation
I read on a post
Big Bang and Cosmic microwave background radiation?
We detect light from another 13 billion years ago does this mean that one billion years ago we could only detect light from about ...
2
votes
1answer
208 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"?
1
vote
2answers
192 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
207 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
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 ...
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 ...
5
votes
2answers
112 views
Why does the homogeneity of the universe require inflation?
They say inflation must have occured because the universe is very homogeneous. Otherwise, how could one part of the universe reach the same temperature as another when the distance between the parts ...
6
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3answers
154 views
Where does the light of the Big Bang come from?
I'm wondering whether the residual light of the Big Bang comes from one particular direction and what possibilities do we have to detect its position?
8
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4answers
411 views
Did really everything begin with a state with very low entropy?
As emphasized by Penrose many years ago, cosmology can only make sense if the world
started in a state of exceptionally low entropy. The low entropy starting point is the
ultimate reason that the ...
6
votes
1answer
188 views
Was the universe a black hole at the beginning?
Big bang cosmology, as far as I understand it, says that the universe was super hot and super dense and super small. It looks like that all the current matter, seen and unseen, were compressed to ...
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 ...
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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
227 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 ...
