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3
votes
1answer
241 views

What is the universe 'expanding' into? [duplicate]

We say the universe is expanding, and by expanding we mean the distance between objects gets larger over time. We call that "Metric Expansion of the Universe". So far so good. I kind of get the idea ...
1
vote
1answer
107 views

What arguments are in favour of an atomic structure to space-time?

The atomic theory as first theorised by Democritus has been successfully applied to matter and to energy (quanta). Space-time is still generally seen as a continuum. What arguments are there (if any) ...
1
vote
0answers
27 views

CMB radiation and holography

If in principle someone have the exact data of the CMB of our universe and unlimited computability power, to what extent it is possible to determine how the universe should look like? Does it fully ...
1
vote
2answers
60 views

Expanding universe and the peculiar velocity

Hubble's law states that the universe is expanding with a velocity equals Hubble's constant*distance from earth. But, recent findings show that the Andromeda galaxy is actually blueshifting towards us ...
3
votes
0answers
94 views

What is the theoretical geometry of bubble universes?

My research has led me to look into the idea of bubble universes which I don't know very much about. The first thing that I am looking for is understanding or visualising how could many bubbles ...
0
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0answers
58 views

What is the future of our universe?

Is the universe heading towards a Big Freeze, a Big Rip, a Big Crunch or a Big Bounce? Or is it part of an infinitely recurring cyclic model?
3
votes
3answers
147 views

Faster than light galaxies/clusters?

A few years ago in an astronomy course, we calculated some (transverse?) velocity of a moving object and got super luminal results. The answer was apparent and not physical velocity of the object. ...
2
votes
2answers
109 views

Is it possible to detect if everyting in the Universe is changing size?

This may be a trivial question, but I cannot find a good answer to it. What would happen if the size of everything in the Universe is multiplied by some constant factor at the same time, let's say ...
0
votes
1answer
70 views

Boundaries of Black Hole and Observable Universe

Are the boundaries of a black hole, the event horizon, similar to the boundary at the end of our observable universe?
0
votes
1answer
89 views

How long would it take for a galaxy to collapse without dark matter?

I am trying to understand the effects of gravity in the Cosmos without complications of Dark Matter/Dark energy issues. So my question is, assuming that a galaxy (for example, the Milky Way) does not ...
0
votes
1answer
49 views

A well-defined quantum probability in the beginning of the universe?

In mathematics or statistics, a well defined probability requires a large sample space. However, in the beginning of the universe, when the first quantum collapse happened, the sample space contains ...
1
vote
0answers
64 views

How is dark energy calculated

This should be a very simple question. What would be the proper way to calculate Dark Energy in Joules at any point in history and that is consistent with the Standard Model? I'm thinking that ...
1
vote
1answer
58 views

Speed of light's relation with the expansion of the universe [duplicate]

If nothing can travel at the speed of light and light cannot escape the universe, then the rate of expansion of the universe should be equal to the speed of light, why it is not?
0
votes
1answer
49 views

How the mass loss rate by stellar wind is calculated for massive stars?

I have been searching for some examples about the different rates at which massive stars lose their mass by stellar wind, but I haven't been able to get anything other for the sun. To be more ...
-1
votes
3answers
144 views

Can the Cosmological Constant explain an accelerated expansion?

From what I've learned so far, it appears that all models that attempt to explain the expansion of the universe are either based on Lambda-CDM or quintessence. The former support a big bang with ...
2
votes
1answer
96 views

What is the equation for the scale factor of the universe, a(t), for the best fit of data to the $\Lambda CDM$ Model of Cosmology?

Ideally I like a single formula or multiple formulas for different time ranges that would cover the time from the end of inflation through 100+ billion years after the big bang using the $\Lambda ...
1
vote
1answer
139 views

Equation for Hubble Value as a function of time

I am trying to write the equation for the situation where the Hubble parameter $H$ would be changing over time. In other words, it would represent an accelerated expansion of the Universe. That is, ...
0
votes
1answer
73 views

How is it possible for you to be at the centre of the universe wherever you are? [duplicate]

I saw on Richard Hammond Builds A Universe on BBC2 a few days ago that you are always at the center of the universe wherever you are. Surely this is illogical, because you could never get to the edge ...
-1
votes
1answer
94 views

If the universe can expand at a speed faster than that of light, why don't we feel the effect? [closed]

the universe, as I have read, is capable of inflating at a speed faster than that of light! How is that even possible if we don't feel the effect? or does it affect us?
1
vote
0answers
114 views

Does space expand locally without restriction in freefall to central region of black hole?

It is often stated that a distant observer will observe a freefalling object as experiencing an infinite journey to the event horizon, but that a traveler in the local frame will experience a ...
1
vote
1answer
116 views

Metric expansion of space - past, present and future

Scientists say that out universe is expanding faster and faster. This was detected via the red-shift effect. Farther galaxies are moving from us faster than those that are more closely. But how can ...
4
votes
1answer
286 views

Is there a center of the Universe if the Universe is finite?

Ok, let me make myself clear. I saw all the other questions related to the question, but none of them actually asks the question the way I would put it and therefore no one answers it the way I want ...
1
vote
4answers
229 views

The universe is expanding but why the galaxies have no motion?

It is said that the universe is expanding and the galaxies are moving apart. I understand that the space between every two galaxies is increasing. Doesn't this seem to imply that the galaxies will ...
0
votes
1answer
97 views

LHC Experiments for finding parallel universes?

I watched this video featuring Michio Kaku explaining parallel universes. In the last two minutes he said that experiments in the LHC could reveal that there might be parallel universes and then he ...
8
votes
8answers
397 views

As the universe ages, will we see more stars or less?

After a very long time will we see more stars (due to the fact that more light is get to us) or less stars (as the universe expends and light have to pass larger distance)? In general, can stellar ...
6
votes
3answers
193 views

If the universe is full of dark matter, why is it only 2.73 K cold?

people! I am just a physics layman, but I recently watched a documentary about the universe and it was told that the universe is full of dark matter and energy and the universe is empty, so that ...
5
votes
1answer
114 views

Lower limit of the size of the Universe? (WMAP)

The measurement of the WMAP satellite resulted a planar geometry of the universe with a 0.4% uncertainity (http://en.wikipedia.org/wiki/Shape_of_the_universe). If there is a little deviation from the ...
1
vote
1answer
132 views

How certain is the heat death of the universe?

According to our current scientific knowledge, how certain is it that heat death shall be the ultimate fate of our universe, and why? Are there any serious hypotheses competing with heat death, and if ...
0
votes
3answers
564 views

Whats left at the center of the Universe after Big bang?

If you consider big bang. According to that What's left at the center of universe where the Big bang occured?
2
votes
1answer
97 views

The universe being finite

I always thought we didn't know if the universe is finite or infinite. However is it true that the universe (not just the observable one) is finite with no boundaries? The articles arXiv:0901.3354 ...
0
votes
5answers
237 views

Why does the universe follow the uncertainty principle?

I have been thinking about this question for quiet a long time but, couldn't make up an answer myself. Usually when someone asks about why a system is the way it is we answer it by saying that it is ...
4
votes
1answer
138 views

Can the total amount of energy in the entire universe be quantified?

Classical thermodynamics leads one to believe that if energy is transferred, and the universe is heading for maximum entropy, then back extrapolating to moments before the big bang, one could find a ...
8
votes
1answer
126 views

Different age of universe

According to general relativity time runs slowly near a massive body. So, I have a question bothering me from some time, that if time for every body/object in universe runs at a different rate, then ...
0
votes
1answer
114 views

Big Bang and Spherical Symmetry

If the universe did indeed start with the big bang why is the universe not spherically symmetric? As per Wikipedia entry on Big Bang, (and my understanding as well) big bang is the best explanation ...
0
votes
2answers
137 views

Does light have an unending journey?

When we shine a torch in a room its light travels to the back of the room. What happens to the light of a star ? I dont suppose we can say it continues to travel to the back of the universe as the ...
3
votes
1answer
174 views

Can universal continuity be experimentally falsified?

It is an unresolved question whether the universe is discrete or continuous in its intricate quantum level structure. See for example: Is the universe finite and discrete? How could spacetime become ...
-2
votes
1answer
181 views

Why does mass in the universe have no limit in large size, but has a limit in small size?

We found VY Canis Majoris, a star so big it can't even be seen in scaled illustratations with the sun itself. However, we stop at particle physics, or quantum mechanics, i.e. particles, subatomic, ...
0
votes
2answers
134 views

Big Bang, What is wrong with such thinking? [closed]

Also if I think the Expanding of Universe like this: At the Start : The Amount of Matter and Anti-Matter is equal and they annihilate and all we had is Large Amount of energy. But some 'X' Thing, ...
4
votes
3answers
207 views

What is the opposite of the Planck length?

What "large size" unit of length could be considered at the opposite end of spectrum from Planck's length? Is there a table of smallest and largest value for various physical quantities that can be ...
0
votes
3answers
169 views

Age of the universe in years

It seems to be commonly accepted that the Big Bang occurred roughly 13.7 billion years ago. My question is what is the meaning of the year in this context? When I type year definition into google, ...
3
votes
4answers
348 views

The inner workings of the Olbers paradox

A long time ago I was told that the universe is finite. The provided "proof" (or reasoning), known as Olbers' paradox, was that on infinite universe there would be an infinite number of stars, and ...
12
votes
5answers
744 views

Proof that Our Planet is 1D

I have took a discrete mathematics course this summer and there we talked about power of groups and functions,and yesterday I though and realize that if we can map all the 3D coordinates with a one on ...
2
votes
1answer
60 views

Thermodynamics and Energy conservation in the Scope of the Universe

According to the 2nd law of thermodynamics, no system can be a 100% efficient. Looking at the universe as it's own system, is it an exception to the rule (a system that doesn't lose any energy)? If ...
4
votes
1answer
283 views

Is “A Brief History of Time” still up to date?

I have recently found my copy of Hawkings' A Brief History of Time which I have never finished. This time I'm determined to read it all the way through. However, the book is now almost 25 years old. ...
2
votes
0answers
82 views

Is everything in the universe discrete? [duplicate]

When beginning my education, I regarded nearly everything as continuous and analog in nature: Physical objects could have any mass on a continuous scale Light sources could emit any intensity of ...
0
votes
0answers
88 views

Calculating the age of the Universe now and 30 billion years from now [duplicate]

I am confused about the age of the Universe. If you calculate it by $1 / H_0$, won't the answer be roughly the same today as it will be 30 billion years from now? I know $H_0$ is a parameter, not a ...
1
vote
2answers
152 views

Does the black hole only increase?

I don't understand this: The more mass a Black Hole has, the more gravity it create! The more gravity it has, the more mass it can get! With this lines, someday, all the universe will be a black ...
1
vote
3answers
96 views

What happened to high temperatures in the universe?

We know that after the big bang the temperature was about 10^32 K. But now the average temperature of the universe is about 4 K. What happened to the temperature at that time? Where did it go?
0
votes
2answers
150 views

What is the universe expanding into? [duplicate]

Due to curiosity, it made me wonder what is outside of the universe, is it a new chemical or just empty space? But empty space have protons appearing and disappearing in it, it basically still has ...
-5
votes
2answers
608 views

Is the total mass of the universe constant in time? [duplicate]

Is the total mass of the universe constant in time?