Questions tagged [big-bang-theory]
Questions regarding the currently prevalent cosmological model for the origin of the universe.
133
questions
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1answer
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Understanding The Fluctuations In The CMB Maps
If I'm understanding this correctly the fluctuations in CMB are a result of the "last scatter" of photons when electrons joined together with nuclei that before this formed plasma. CMB is among other ...
8
votes
1answer
132 views
How do we know so many details about Big Bang, but we do not know if Universe is finite/infinite?
I understand that this question may be too vague, but I am confused about the following:
On one hand we know a lot of "details" about Big Bang, like really precise details, evolution of universe, age ...
0
votes
1answer
163 views
If space is negative energy and matter is positive energy then does that mean the universe is finite?
I was reading a book by Stephen Hawking, it was written that universe is made up of 2 ingredients,i.e., space and energy and space was the negative energy, so they add up to 0. But since space is ...
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1answer
162 views
What does it mean for space to expand?
In this YT video Michelle Thaller says The Big Bang wasn’t an explosion but an expansion and as such there's no empty center where the explosion would've been.
To explain expansion she uses the ...
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0answers
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Expansion of space or constriction of length scales?
According to wikipedia,
"Technically, neither space nor objects in space move. Instead it is
the metric governing the size and geometry of spacetime itself that
changes in scale. Although ...
24
votes
6answers
7k views
Why do galaxies collide?
If the universe is expanding outward, what is the processes for one galaxy to get off track enough to collide with another?
Say, the Andromeda Galaxy and the Milky Way.
0
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1answer
58 views
Have we measured or found evidence of a detectable origin point of the big bang? [duplicate]
Based on reading the wiki page of the big bang, a simple question with a probably not a simple answer came to mind.
The statement on the wikipedia page was.
Since Georges Lemaître first noted in ...
1
vote
0answers
64 views
Is it possible for 'pre-big bang' empty space to have the property of being able to spawn matter and/or energy into existence? [closed]
.. and if so, wouldn't this also mean that during this event, time would be created as a collateral, as a canvas for this property to manifest?
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vote
0answers
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Expansion of space - how do we end up with an unobservable region?
I've just been answering a question on this issue,in physics SE,and realised that my answer conceals a point I don't myself understand.
I understand that
The expansion of metric isn't affected by ...
4
votes
1answer
125 views
How much helium has been created since the Big Bang?
When I try to find figures for the amount of helium today and just after the Big Bang, I get similar figures. I was expecting that all of the stars since then would have created more helium. Is the ...
3
votes
0answers
40 views
How did the Big Bang occured if before that there was no time? [duplicate]
I am thinking, that if the Big Bang created time, it implies that before the Big Bang there was no time (correct me if I am wrong).
My question is that, if there was no time before the Big Bang, how ...
4
votes
1answer
113 views
How can you verify the theories presented on TV shows like “How the Universe Works” is current and/or valid? [closed]
There are many TV shows such as "How the Universe Works" that explain theories about the origin of the universe such as the Big-Bang Theory.
What resources can I access to verify the scientific ...
0
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2answers
132 views
How does science knows what is the early universe?
I've read about Hubble seeing the brightest quasar in the early universe. Question is, how does science knows what is early and what is late?
Please correct me if I'm wondering, but after the big ...
1
vote
1answer
131 views
Why more matter still left after collision with anti-matter?
Question implies all, why is that? Why we exist even after equally creation of matter and anti-matter, any possible exception?
2
votes
0answers
73 views
Is there a theory about a collision between a shrinking universe and a new expanding universe?
I recently read a post on a discussion board about the creation of our current universe that stated, and I quote:
[T]he shrinkage activity of the old universe and the new Big Bang expansion ...
2
votes
2answers
257 views
How could time only have started with the Big Bang?
I understand that before the Big Bang time (as well as dimensions) didn't exist. But how could this be? If there was no time then nothing could change, and so time itself couldn't come into existence.
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vote
1answer
130 views
Is it possible that the Universe is expanding due to additional Big Bang events?
Is it theoretically possible that the Universe is expanding due to additional Big Bang events that have occurred at the same location that the original Big Bang occurred at?
Perhaps there has been an ...
1
vote
1answer
121 views
How thick is the cosmic microwave background, including the part we cannot see within the observable universe?
What I want to know is how thick the observable universe is from the point of the cosmic microwave background and beyond.
It appears the thickness of the cosmic microwave background itself (the part ...
1
vote
3answers
101 views
If the Higgs field only formed after the Big Bang, how was hydrogen formed?
These two statements seem to conflict, but since we're here they can't:
Electrically charged particles cannot be massless.
Hydrogen was created at the moment of the Big Bang.
However, the Higgs ...
1
vote
3answers
394 views
How did space start?
How did this 'black fabric' that we call space start? How was it made? How was the initial singularity formed? How did the first atom come into existence?
If it all started from a tiny particle that ...
0
votes
1answer
850 views
What created the big bang's singularity?
I have heard theories for the big bang like: of another universe existing before the Big Bang, or an unstable white hole that blew up, or our universe detaching from our mother universe, or our ...
0
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1answer
71 views
Fundamental axioms in LCDM
What are the axioms (if any) behind the LCDM model of cosmology?
NB: axioms, not postulates (e.g., inflation)
2
votes
1answer
107 views
Just after the Big Bang, was the space, in its entirety, filled with Hot gas?
After the Big bang occurred, was the space filled with hot gas totally?
If there's any problem in my question please inform me. Thanks!
3
votes
1answer
55 views
calculation of characteristic expansion time of the universe
Hubble's constant is estimated at 15km/s at a distance of million light years, without considering effects of mutual gravity, relativity, etc.
I am trying to calculate the characteristic expansion ...
0
votes
1answer
56 views
Location of Big Bang [duplicate]
Can I point to somewhere in the sky where the Big Bang happened? A pathway so to speak on where we (and our progenitor elements) came from?
0
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1answer
85 views
Singularity at the time of origins
According to the big Bang Theory, the universe have started from a point and it describes how the universe expanded from a very high-density and high-temperature state.The initial singularity was a ...
5
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1answer
128 views
Why Helium could be produced in first minutes of big bang but not heavier elements
At what extent could be sure that no heavier elements than helium could be produced, if we know that matter in universe today is about 25% composed on helium, why could be so sure that the kind of ...
3
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2answers
183 views
BIg Bang Happened everywhere
According to the Friedmann equations big bang happened everywhere, but if we account for inflation theory, big bang did not happened everywhere. How ? Anyone please explain. Please see the video for ...
2
votes
1answer
110 views
Is it fruitful to search for a correlation between rates of in-falling matter in black holes and the expansion rate of our universe? [duplicate]
To my understanding, white holes are hypothetical objects that are time-reversed black holes; black holes gravitationally "suck in" matter whereas white holes "spit" matter back out. As such, I think ...
2
votes
1answer
555 views
How could the universe be a few light years across just 1 second after the big bang?
I was skimming through Neil deGrasse Tyson's book Astrophysics for People in a Hurry when I noticed he says something curious on page 26:
"By now, one second of time has passed [since the big bang]. ...
9
votes
1answer
658 views
Was the whole Universe close to Big Bang very small, or just very dense?
I am sorry this question is probably silly for professional astronomers, of which I am not one.
I often hear at lectures that immediately after the Big Bang, the universe was small, say, the size of ...
2
votes
0answers
50 views
How the observed deuterium abundance constrains big bang nucleosynthesis?
I know deuterium can be used as a good tracer to constrain the big bang nucleosynthesis. But can anyone tell me the in details how this is actually done?
2
votes
1answer
121 views
How does inflation justify the nonexistence of magnetic monopoles?
It is said that inflation justifies that magnetic monopoles don't exist. Can anyone explain how inflation theory explains the non existence of magnetic monopoles?
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vote
1answer
485 views
What is beyond the observable universe? [closed]
What is beyond the edge of the observable universe? Scientists say that the Big Bang is the cause of all creation in the known universe, but it would seem the bang must have happened in the center of ...
3
votes
3answers
610 views
How can the universe be expanding faster than speed of light? [duplicate]
So the story goes like this:
A long time ago, 13.799±0.021 billion years to be exact, something happened. It was a big bang, loud explosion and universe came to existence. It grew and grew, and now ...
0
votes
1answer
238 views
Why do we we even exist? [closed]
It came to my mind one day that why does this universe even exist and why do we even exist and like we are enclosed in the so called atmosphere and a floating rock in space called the Earth, so is ...
3
votes
2answers
168 views
Is there a way to know how the magnetic field was at the very beginning of our universe?
I recently read that
Gamma-ray bursts are catastrophic events, related to the explosion of massive stars 50 times the size of our sun. If you ranked all the explosions in the universe based on ...
1
vote
1answer
162 views
Was Milky Way formed after Sagittarius A Explosion?
Is it possible that most galaxies (and our galaxy) were formed from leftovers of supernova explosions?
In order to have a black hole 4,000,000 x solar mass the initial mass of the star should have ...
2
votes
1answer
2k views
Why did the big bang produce a low entropy universe?
In order for the universe to be as it is, containing stars and galaxies, it is a requirement that the early universe was at a relatively low entropy state.
Why did the big bang produce this low ...
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vote
1answer
311 views
Does a White hole lies behind a Black hole?
While reading about a White holes, I stumbled upon a question "Where does the matter emitted by a White hole come from?" There seems to be 2 possible candidates:
It was the matter engulfed by a ...
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votes
2answers
132 views
How does the earth not continue accelerating? [closed]
I'm not scientist at all so the answer might be obvious but I was pondering about the big bang. I started wondering how is it possible that the earth had to accelerate at some point in history to the ...
0
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1answer
106 views
From where so much of energy would have arrived as was required for such a giant universe to have come into existence? [closed]
If we convert the mass of all the stars and all the planets which must be weighing trillions and trillions of tonnes by the equation E = m.c^2 it gets converted into an unimaginable amount of energy. ...
5
votes
2answers
323 views
Could the big bang have created super massive black holes?
I understand that space was compressed to a single point and that during the big bang all points within that expanded away from each other at phenomenal speeds. I also have heard that during this the ...
4
votes
1answer
2k views
Amount of energy of the Big Bang
What is the currently accepted estimated range of the amount of energy of the Big Bang event?
In joules at some estimated size, so a temperature may be calculated.
For context, I wonder if the ...
3
votes
2answers
141 views
Collision of Galaxies
According to the big bang theory, the universe started from a small intial point and is essentially expanding. However, my question is that if the universe is expanding how is it possible for galactic ...
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vote
2answers
412 views
Which constellation would appear to revolve around Denab,Vega or Thuban when axis of the earth would point toward them?
We have been calling the star by looking at which we can make out the direction of the North Pole the North Star. This was the only method at the disposal of the sailors during the days when they did ...
4
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1answer
297 views
What existed before the big bang [closed]
What existed before the big bang?
What all thing are there inside big bang object ?.
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3answers
162 views
What made cooler temperatures suitable for atom formation?
I have read in relation to Big Bang theory that after 300,000 years of big Bang temperature was reduced to 4500 Kelvin and this gave rise to Atomic matter.So,my question is why reduction in ...
9
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2answers
157 views
How Good Are the Upper Limits on Heavy Elements?
There are between 90 and 254 stable nuclei all the way up to element number 82. In discussions and graphs about big bang nucleosynthesis nothing above lithium is even mentioned. It's a pretty safe bet ...
2
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1answer
513 views
Did uncertainty principle triggered big bang? [closed]
So i want to know why world changed from the empty state ( no materials, energy and ...) from to the it's staring state in the big bang shape?
based of this answer's to this question:
big-bang-thoery-...
