All Questions
Tagged with cosmology experimental-physics
62
questions
81
votes
6
answers
7k
views
What was the major discovery on gravitational waves made March 17th, 2014, in the BICEP2 experiment?
The Harvard-Smithsonian Centre for Astrophysics held a press conference today to announce a major discovery relating to gravitational waves. What was their announcement, and what are the implications?
...
- 5,569
1
vote
1
answer
120
views
Multiverse explanation of fine tuning of cosmic constants
Physicists proposed the idea of multiverses to explain extraordinary fine tuning of the cosmic constant and physical laws which is essential for rise of life on earth.
Is there any experiment that ...
9
votes
1
answer
1k
views
What are the different ways to measure the spatial curvature of the universe?
Just what the question asks. Assuming the Friedmann-Rovertson-Walker (FRW) metric, what measurements can be performed to determine the spatial curvature of the universe.
- 3,492
17
votes
9
answers
17k
views
What is the difference between translation and rotation?
What is the difference between translation and rotation ?
If this were a mathematics site, the question would be at best naive.
But this is physics site, and the question must be interpreted as a
...
- 3,798
2
votes
1
answer
3k
views
Is the total angular momentum of the universe zero? [duplicate]
I know that having a net angular momentum will contradict isotropy of the universe by preferring a specific direction. But is there any experimental data on the total angular momentum of the universe ...
- 6,004
29
votes
3
answers
10k
views
How do people calculate proportions of dark matter, dark energy and baryonic matter of the universe?
The Wikipedia page on dark matter mentions that the Planck mission had revealed that in our universe ordinary baryonic matter, dark matter and dark energy are present in the ratio: 4.9%, 26.8% and 68....
- 1,057
4
votes
2
answers
444
views
Cosmological triangle with PLANCK results
Is there an updated version of the cosmological triangle with recent PLANCK results included?
- 51
7
votes
2
answers
561
views
What's the significance of large-scale anomalies in CMB
What's the significance of large-scale anomalies in CMB that are confirmed by Planck? I've read somewhere that the cold spots can provide support for string theory or it may be due to a parallel ...
- 71
3
votes
1
answer
365
views
Observable (in principle) signal of a bubble collision in eternal inflation
Assuming a scenario of eternal inflation with a lot of "bubble universes" expanding, Lenny Susskind explains here that a potential signal of a collision of our universe with another bubble could be a ...
- 9,581
4
votes
2
answers
934
views
How is it possible to come to a conclusion that Universe is a result of the Big Bang while we aren't able to observe the entire Universe?
-I'm not a religious person so this is not a denial. I'm just trying to understand the most fundamental topic about Universe.
-I know the Big Bang cosmological model is not a law but it's a theory.
-...
8
votes
2
answers
1k
views
Compactness of spacetime: experiment and math
It is common to find models built on a compact spacetime. In mathematics, compactness is a very nice property $-$ and lot of powerful results depend on it.
But
how safe is assuming compactness of ...
- 1,544
4
votes
1
answer
253
views
How could we experience multiverse through cosmic background radiation?
I'm reading a book about string theory, and it tells me in the future it could be possible to detect existence of other bubble universes through cosmic background radiation. If true, what could we ...
- 279
20
votes
3
answers
8k
views
Why do neutrino oscillations imply nonzero neutrino masses?
Neutrinos can pass from one family to another (that is, change in flavor) in a process known as neutrino oscillation. The oscillation between the different families occurs randomly, and the likelihood ...
- 1,516
10
votes
4
answers
1k
views
Experimental evidence for parallel universes/multiverses
My idea of physics is that it is a collection of mathematical laws relating observables. And that one can perform alot of mathematical derivations on these laws to produce new laws between observables....
- 101
2
votes
2
answers
193
views
Observation of cosmological topological defects
Are there any projects/experiments running for the observation of topological defects (domain walls, monopoles, etc)?
Are there any past/canceled or future such projects?
- 1,261