All Questions
45
questions
0
votes
1
answer
61
views
What is the total mass-energy of baryonic matter?
From what I understand, conservation of energy does not apply to the total energy of the Universe, because it constantly expands and the new, created space has a constant non-zero energy of its own. ...
- 413
0
votes
0
answers
47
views
Transition to Neutron Star
If we're asked to believe that the explosive aspect of a supernova results from a rebound of residual free falling matter off of the stellar core, shouldn't we also be asked to believe that transition ...
user394592
0
votes
2
answers
104
views
Matter and Antimatter coexistence [closed]
Isn't it possible that matter and antimatter coexist? Recently, the ALPHA experiment at CERN has been looking into this topic. And I read about it from Fermilab's website, so they are saying how our ...
0
votes
1
answer
93
views
Event after big bang that cause dark matter [closed]
When the universe was formed by the Big Bang, what was the event that made some matter visible to us, while some became dark matter?
0
votes
2
answers
97
views
Mass matter, energy and "massless matter"
This is perhaps a rather silly question, or rather a matter of convention, but I would like to hear arguments about the appropriateness of certain definitions.
Traditionally, in chemistry and in pre-...
- 1,640
6
votes
1
answer
353
views
How would the universe look like without matter?
I was wondering how the universe would look like if it would have been perfectly symmetrical in terms of matter and antimatter. If I understand correctly, there would be no "particle" but ...
- 357
1
vote
0
answers
52
views
Expansion of the Universe inside mattar [duplicate]
When talking about the expansion of the universe we usually refer to the Friedman equations so we assume homogeneous and isotropic solution to Einstein field equation which is true on cosmological ...
- 1,734
2
votes
1
answer
92
views
Total number of particles in the universe (according to Planck Surveyor measures, 2018)
Recently, Marco Ajello et al. (2018) has estimated the total number of photons in the whole observable universe as:
$$N_\gamma \approx 4\cdot 10^{84}.$$
On the other hand, the ratio of baryons to ...
- 1,640
-3
votes
2
answers
266
views
Does anyone really know how dark energy/matter works?
If dark energy has no physical interaction with normal matter but it does interact with dark matter, wouldn't that cause an interaction with normal matter through its interaction with dark matter and ...
- 1
0
votes
1
answer
79
views
What are the conditions needed for baryogenesis? [duplicate]
Physicists have created antimatter in the laboratory. But when they do, they create an equal amount of matter. That suggests that the Big Bang must have created matter and antimatter in equal ...
user318515
2
votes
2
answers
458
views
Why do matter and radiation densities scale differently in expanding universe, when all matter is energy and all energy is matter? [duplicate]
I sometimes see the first Friedmann equation expressed with different terms for the density of "matter" and the density of "radiation". It is said that with an increase in scale ...
- 213
0
votes
1
answer
41
views
How the universe is expanding? [duplicate]
If universe is expanding with the velocity of light then why the distance between earth and sun is constant? Also why the distance from one Galaxy to another remains constant? And so on...
-1
votes
1
answer
87
views
Does the expansion of the Universe cause internal stresses in solids (and other substances with similar internal resistance forces)? [duplicate]
Is my understanding correct?
Weren't it for the internal resistance forces between particles in a solid object, the expansion of the Universe would continuously increase the distances between all of ...
- 245
2
votes
0
answers
59
views
Gravity in a universe where all energy has been turned to mass [closed]
If all energy in the universe was turned to mass would gravity work?
- 21
0
votes
3
answers
40
views
Are the constituents of the known universe matter (including antimatter) and electromagnetic radiation?
Is it correct to say that the constituents of the known universe are matter (including antimatter) and electromagnetic radiation, leaving aside the comparatively hypothetical ‘dark’ entities? This is ...
- 135