Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange
Join us in building a kind, collaborative learning community via our updated Code of Conduct.

Questions regarding the universe shortly after it's formation

-1
votes
1answer
16 views

Field excitement in quantum field theory? [closed]

How at the beginning of this universe the fields as proposed in quantum fields theory get excited?? How exactly these fields originated?
0
votes
2answers
117 views

Why do we presume that the universe has always expanded?

When I read about the universe having always expanded from a 'singularity', I can't help but wonder if that is perhaps not the case. If a singularity is a point at which everything is infinite and is, ...
7
votes
1answer
114 views

Does the CMB pattern evolve in a human lifetime?

I was thinking, as CMB is a snapshot of a slice of the Universe during recombination, how much the cmb is changing with time ? I mean as we progress in time we look a CMB a bit more faraway each time, ...
1
vote
1answer
47 views

Who discovered the relation between CMB fluctuations and large-scale structure formation?

I haven't been able to find a reference to the first who showed that the small density fluctuations in the cosmic microwave background led to the formation of large scale structure as we know it.
6
votes
1answer
181 views

Portion of universe visible if gathering image from inflationary epoch

Apologies in advance for my over-exposure to pop science. I want to propose a telescope powerful enough to collect imagery from 10^-32 seconds after the “Big Bang”, or as soon as the end of the ...
-5
votes
1answer
87 views

Estimates VOLUME of the ur-Supermassive Black Hole of this universe

Assuming Prof. Poplawski's "universe in a black hole" ( and at Arxiv here ) concept is true--that our universe is the result of a nonsingular Big Bounce from a supermassive black hole (SMBH) under ...
1
vote
0answers
30 views

Question about finding energy density of a fermionic-bosonic gas

We know that energy density is given by this formula: $$u = \frac{1}{V}\int_0^\infty\epsilon_pf(\epsilon_p) g_s V/h^3 4\pi p^2 dp$$ Where $\epsilon_p=pc$ for relativistic particles. also $f(\...
1
vote
1answer
91 views

Primordial supermassive black holes. How old are they?

I know that astronomers have detected supermassive black holes in the early universe. What was the age of the universe at which these black holes were detected? In other words how long is it thought ...
1
vote
2answers
83 views

Expanding universe

If the first stars in the universe were formed 400 million years after the big bang, and the universe is expanding, should that stars at that time not been in our cosmic backyard? And should their ...
4
votes
2answers
223 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 ...
3
votes
1answer
59 views

Ionization Fraction of Helium in alternate, He dominated early universe

I'm asked to verify an expression for the ionization fraction of helium in a universe in which helium dominates baryonic matter. I'm given that the ionization fraction $X = \frac{n_{He^+}}{n_{He^+}+...
7
votes
2answers
355 views

How were the first stars formed?

In class, we read a Scientific American article, "Cloudy with a Chance of Stars" that explained how the cores and the dust around them formed stars(he called them eggs for a chicken/egg analogy, where ...
0
votes
2answers
133 views

What is the probability that we are the first ever intelligent life in the whole universe? [closed]

What is the probability that we are the first ever intelligent life developed all over the universe? Everything starts somewhere, Is there any probability that we are the beginners to be part of ...
4
votes
1answer
234 views

What existed before the big bang [closed]

What existed before the big bang? What all thing are there inside big bang object ?.
29
votes
1answer
4k views

Why didn't the Big Bang produce heavier elements?

Shortly after the Big Bang, temperatures cooled from the Planck temperature. Once temperatures lowered to 116 gigakelvins, nucleosynthesis took place and helium, lithium and trace amounts of other ...
2
votes
1answer
243 views

What is the meaning tiny bundle of energy smaller than an atom

At the beginning of a video on youtube titled "history of the world in 2 hours", it is said that "every thing begins with this tiny bundle of energy smaller than an atom". I want to know what it means....
1
vote
1answer
155 views

How could lithium burning take place in a quasi-star?

According to Begelman et al. (2008), one of the most distinguishing features of the hypothetical quasi-star is that it's supported by radiation pressure from the accretion disk of the black hole in ...
0
votes
0answers
87 views

$\Lambda$CDM Model and the early stages of the Universe

We know that the radiation dominant era lasted for 50,000 years, how? What equations give us the result of 50,000 years and how are we certain that we are talking about radiation dominant era, same ...
4
votes
1answer
168 views

Is it possible to get a glimpse of the Big Bang through gravitation waves?

I read in an article announcing the detection of gravitational waves by LIGO that it will be possible to detect them from the Big Bang. Is this true?
0
votes
1answer
69 views

What was the entity/particle/state at the time of the Big bang?

At the time of the big bang if there was an original entity, what were it's attributes(if applicable) - mass, electric charge, color charge or spin? Can the current matter and dark energy together ...
1
vote
2answers
164 views

What happened just before the Big bang? [duplicate]

Does the CMB contain any clues to what caused the Big Bang? Does a mathematical model theorize it?
2
votes
2answers
251 views

Is time itself speeding up universally?

Time moves more slowly near a mass than in relatively empty space. For example, I get that an observer would see someone falling into a black hole to appear to move more slowly and get "stuck" on the ...
1
vote
1answer
77 views

How come, in our lifetime, we will see the first stars which ever formed?

Isn't it an unlikely coincidence that we live in such special times, that we will have observatories (JWST) that see all the way back to the first starlight in the universe? Are we dreaming, and is it ...
2
votes
1answer
317 views

Mass distribution in the early universe

The latest big quasar find at ~12.8 bn LJ with an estimated mass of 12 bn M☉ (see e.g. http://www.newscientist.com/article/mg22530104.000-ancient-black-hole-had-an-inexplicable-growth-spurt.html) puts ...
2
votes
1answer
480 views

Big Bang / Big Crunch cycle?

I've been reading some of Stephen Hawking's work on the theory of the expansion (and ultimate contraction) of the universe and was curious if anyone has every hypothesized that the universe has ...
3
votes
1answer
146 views

Matter and Antimatter Interaction in the early Universe

Well it is said that during the Big Bang, things were created in pairs: one matter and one anti-matter. I think its a part of the Big-Bang Theory. It is also said that matter + anti-matter - Energy ...
2
votes
1answer
610 views

Time-density and time-temperature functions of the Universe since the Big Bang

I am looking for these... functions. I want to be able to say, "at a 1873. second there were around 54230000000 K temperature and 0.00435 kg/m^3 density". On the net I could find only tables or ...
1
vote
3answers
121 views

Could the universe have evolved differently?

Given the initial conditions at the Big Bang, could our universe have evolved any differently? In other words, did the initial conditions predetermine every stage in the evolution of the universe to ...
-3
votes
1answer
195 views

Astronomy questions I wondered for hours [closed]

I read a question posted by a community member in my community that shocked me, I think it contains some pretty cool astronomy questions that I cant wait for you scientists to answer. I am asking this ...
4
votes
1answer
1k views

How did the reionization epoch make the universe “transparent”?

I've been reading about the reionization epoch of the universe, and it isn't entirely clear to me. As I understand it, very shortly after the big bang the universe was ionized, with the electrons ...
6
votes
3answers
201 views

Flatness of the universe?

How does inflation explain why the curvature in the early universe was flattened out and now results in a flat universe?
1
vote
1answer
63 views

Sources of astronomy-related dataset?

I'm doing a project for a statistics class, and I thought it may be interesting work with a dataset associated with astronomy. I know absolutely nothing about astronomy, unfortunately, and I wouldn't ...
1
vote
1answer
329 views

The reason behind Big Bang

It always amuse us to research about things around us and we always start our research with a question that - what must be the reason for happening of that phenomenon? As we know that the formation ...
2
votes
1answer
56 views

What would the sky have looked like when galaxies first started to form?

If I stood on a theoretical earth at the time that galaxies were just starting to form, what would the sky have looked like? Due to the smaller size of the universe would it have been densely packed ...
3
votes
2answers
546 views

Why are distant galaxies not visible in the observable Universe?

Assuming that the Universe is and has been expanding ever since its creation (Big Bang theory), the galaxies that are now at the 'edge' (not visible theoretically) must have been (at some point in ...
17
votes
3answers
906 views

How do we know the big bang didn't happen in an existing universe?

I understand the evidence for the big bang (expansion, background radiation, etc), but how do we know that it was the start of the universe? Why couldn't it have occurred in an existing, but very ...
12
votes
1answer
339 views

Where is all the antimatter?

The universe supposedly started off with equal parts matter and antimatter and they are said to annihilate each other. Also, nature is famous for it's balance between everything. So all we see is ...
11
votes
1answer
196 views

Age of the universe

We know that the universe is approximately 13.7 billion years old. What methods did we use to discover this? How sure are we about its accuracy?
11
votes
1answer
574 views

Inflation cosmology: slow-roll inflation versus tunneling between two vacua

In slow-roll inflation models, the early inflation of the universe is driven by the flat non-zero part of the inflaton potential, and it ends as the ball rolls down the cliff and the potential energy ...
19
votes
1answer
441 views

Future of CMB observations: How will our knowledge of the early universe change?

The Planck satellite has been presented and awaited for a long time as the ultimate experiments for measuring temperature fluctuations in the cosmic microwave background (CMB) over the full sky. One ...