Questions tagged [early-universe]

Questions regarding the universe shortly after its formation, up to the CMB or even as far as the formation of the first galaxies

Filter by
Sorted by
Tagged with
4
votes
1answer
35 views

Are features in the CMB correlated with features in the SDSS map of the most distant galaxies?

This is a follow up to an earlier question to which @pela gave an excellent answer. Apparently the statistics of the length-scales of the CMB fluctuations are similar to those obtained from other ...
8
votes
1answer
62 views

Is there any correlation between the Cosmic Microwave Background (CMB) and the distribution of distant galaxies?

The Cosmic Microwave Background (CMB) is remarkably isotropic but does exhibit a distinct dipolar Doppler shift and also much smaller but measurable fluctuations in intensity and polarization. ...
1
vote
1answer
91 views

How can a very old star be formed among Population III stars?

After looking at some articles about old stars, (this, that, and this Wikipedia article), I thought about how such an old and small star could have formed. As the early universe had very massive, ...
3
votes
0answers
41 views

What came first: Galaxies or Stars? [duplicate]

In Stephen Hawking's A Brief History Of Time, the book mentions that "in regions that were slightly denser than average...galaxies were born." (pg 123). However, according to many other ...
0
votes
0answers
46 views

What was there before the big bang [duplicate]

we know that our universe is expanding, but we must agree to the fact that it has a limit. It just cant expand till infinity. Eventually there will be a end to time. I thought alot about this and i ...
2
votes
1answer
149 views

What was the size of the universe around 400 million years after the Big Bang?

I was trying to find out how large the universe was around 400 million years after the Big Bang as this is when some of the first galaxies were formed but I am having trouble finding out the answer or ...
1
vote
1answer
182 views

Why is the Cosmic Microwave Background at the same distance no matter the direction we look?

I've read from different sources that: The CMB is visible at a distance of 13.8 billion light years in all directions from Earth, leading scientists to determine that this is the true age of the ...
15
votes
2answers
440 views

What was the absolute limit to the possible sizes of the first stars formed from “primordial material with no metals”?

This answer to Why don't or (can't) stars be more than 325 or so times the mass of the sun? What limits their size? includes the following: ...The upper limit you refer to is for compositions similar ...
7
votes
1answer
69 views

Cosmic Microwave Background Map

When a satellite takes measurements of the radiation from different patches of the sky to construct a map of the thermal radiation of the universe on the surface of a sphere, it would also contain ...
6
votes
1answer
147 views

Why is CMB an evidence of hotter and denser early Universe?

In his book Gravitation and cosmology, Steven Weinberg says that CMB makes it "difficult to doubt that the universe has evolved from a hotter denser early stage". In my understanding, CMB ...
0
votes
2answers
359 views

Size of the Universe before the Big Bang [closed]

I can't understand how all the matter contained in the Universe, was contained in an area the size of a grapefruit before the Big Bang ? How could so much matter have been compressed in such a tiny ...
10
votes
1answer
195 views

Will James Webb see Population III stars?

I have heard that James Webb will see the first stars that our universe produced. Can I assume that we may see galaxies that are so young that all of the stars in them are population III?
15
votes
2answers
535 views

Characteristics of the first planets in the Universe?

What would have the very first planets looked like, based on their most likely chemical compositions? For example: Were they mostly grey gas giants with atmospheres of hydrogen and helium, ...
3
votes
1answer
161 views

Could the Universe really be 12.5-13 billion years old?

My initial reaction is that "this must be wrong" and apparently that's a lot of people's initial reaction according to the article. https://www.nbcnews.com/mach/science/universe-may-be-billion-years-...
3
votes
1answer
71 views

Question about expansion of space time

Was the expansion of space time during big bang uniform if so how come the stars and planets be formed because and matter as well as gravity would have been same everywhere
1
vote
2answers
172 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
votes
1answer
43 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?
1
vote
2answers
160 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, ...
9
votes
1answer
184 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
75 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
197 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 ...
-3
votes
1answer
143 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
45 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
195 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
95 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 ...
6
votes
2answers
386 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 ...
2
votes
1answer
109 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
742 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
190 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
365 views

What existed before the big bang [closed]

What existed before the big bang? What all thing are there inside big bang object ?.
30
votes
1answer
6k 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
309 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....
2
votes
1answer
244 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 ...
4
votes
1answer
188 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
81 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
292 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?
3
votes
2answers
547 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 ...
2
votes
1answer
98 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 ...
3
votes
1answer
333 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 ...
4
votes
1answer
938 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
2answers
219 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
833 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
151 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 ...
-5
votes
1answer
249 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
2k 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
251 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
85 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
461 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
68 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
807 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 ...