# Tagged Questions

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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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 ...
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 ...
1answer
66 views

### Explanation for the notion that physical laws break down at the Big Bang

I've often heard the phrase "physical laws break down at the big bang". Why is this? Divide by zero? Please provide the mathematics.
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 ...
4answers
1k views

### Did time exist before the creation of matter in the universe?

Does time stretch all the way back for infinity or was there a point when time appears to start in the universe? I remember reading long ago somewhere that according to one theory time began shortly ...
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)?
2answers
167 views

### Simplifying the explanation of a low-entropy Big Bang

The claim that the young universe was in a low-entropy state seems at odds with maximal entropy being thermal equilibrium, and the young universe being in thermal equilibrium. I've looked at some ...
1answer
131 views

### Early time in the Big Bang

I am not a physicist, so I would really appreciate using a simple language for the explanation of my question. From what I understood at the early Big Bang the four fundamental forces were unified to ...
2answers
110 views

### Is this a great flaw in big bang theory? [duplicate]

Einstein said that, Time & Space cannot exists without one another. Big bang says, time didn't exist before the big bang. So the Primordial ball referred in the Big Bang theory didn't had any ...
4answers
280 views

### Before the Big Bang

I've heard this saying before I don't know about anyone else. It says, "What ever was before the big bang is something physics can't explain..! Is this saying true (accurate)?
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?
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?
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 ...
3answers
418 views

### How can a quasar be 29 billion light-years away from Earth if Big Bang happened only 13.8 billion years ago?

I was reading through the Wikipedia article on Quasars and came across the fact that the most distant Quasar is 29 Billion Light years. This is what the article exactly says The highest redshift ...
5answers
3k views

### How can something happen when time does not exist?

I saw this documentary hosted by Stephen Hawkins: www.youtube.com/watch?v=WQhd05ZVYWg And if I didn't get it wrong, it says that there was no time before the big bang, time was created there. So how ...
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 ...
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 ...
1answer
102 views

### why gravity exists? [closed]

I always have a doubt on gravity , why does gravity exists ? is there any scientific explanation on gravity ? I know that Gravity exists , i can feel it. But Who is creating all these rules ? ...
1answer
63 views

### What is the age of universe? [closed]

As we know at the time of big bang as mentioned by the scientist the universe expanded faster than the speed of light. So does it mean that at that time all the particles present travelled in the time ...
1answer
82 views

### Is it possible that a black hole sucks energy that is the origin of another universes big bang?

The universe expanded from nothing, right? And black holes may be a "gate" to parallel universes, is it possible that stars that is being sucked in by black holes in our universe may be the origin of ...
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 ...
0answers
25 views

### Where is universe expanding? [duplicate]

According to many physicist space, time and universe came to existence after the big bang. The universe is now expanding since after the big bang continuously. So my question is where our universe id ...
4answers
354 views

### Origins of the universe questions

If the universe is expanding, what is it expanding into? Similarly when the big bang happened where and how did it occur? - Where did the energy come from? Energy can not be created or destroyed does ...
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?
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 ...
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 ...
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 ...
3answers
1k views

### What has been proved about the big bang, and what has not?

Ok so the universe is in constant expansion, that has been proven, right? And that means that it was smaller in the past.. But what's the smallest size we can be sure the universe has ever had? I ...
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 ...
3answers
1k views

### Where does matter come from?

I admit, it's been a few years since I've studied physics, but the following question came to me when I was listening to a talk by Lawrence Krauss. Is there any knowledge of from where matter that ...
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 ...
2answers
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### 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 ...
1answer
299 views

### LHC Big Bang Temperatures

It's been claimed that the LHC's 14 TeV energy produces temperatures comparable to that which occurred very soon after the Big Bang. The well-known $E=1.5kT$ formula from classical statistical ...
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 ...
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 ...
2answers
100 views

### Was the singularity at Big Bang perfectly uniform and if so, why did the universe lose its uniformity?

Am I right in understanding that current theory states that Big Bang originated from a single point of singularity? If so, would this mean that this was a uniform point? If so, as the universe ...
4answers
1k views

### What is our location relative to the Big Bang?

Given what we know about space, time and the movement of galaxies, have we or can we determine what our position is in relation to the projected location of the Big Bang? I've read some introductory ...
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 ...
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 ...
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 ...
1answer
356 views

### Do all the forces become one?

Were the forces of nature combined in one unifying force at the time of the Big Bang? By which symmetry is this unification governed? Are there any evidence for such unification of forces? Has ever ...
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. ...
4answers
323 views

### Does the universe have a center?

If the big bang was the birth of everything, and the big bang was an event in the sense that it had a location and a time (time 0), wouldn't that mean that our universe has a center? Where was the ...
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 ...
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?
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 ...
0answers
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### 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) / ...
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 ...
0answers
401 views

### Was the Big Bang a result of a decayed white hole singularity? [closed]

From my understanding, the Big Bang is theorized to have been a result of matter ejecting from a decayed white hole space/time singularity. ...
4answers
518 views

### Atoms pop out of nothing/vacuum/pre-big-bang?

I saw a great documentary last night about 'nothing'. It's about vacuums, and how if you have a total vacuum atoms will pop out of nowhere! Pretty crazy stuff. Atoms literally coming out of ...
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