1
vote
1answer
44 views

Data/signal from a black hole to observe a singularity

I wonder if a situation is possible where, we measure some signal/property concerning a black hole. Supposing the measurement we make with some telescope, gets us the Fourier transform coefficients of ...
2
votes
2answers
64 views

How do we observe the expansion of the universe?

This is my first question. So I was reading about expansion of the universe and from what I've seen, the only way that we know that universe is expanding is by measuring redshift. Also, here it says ...
2
votes
4answers
128 views

What experiment would disprove Friedmann model of cosmology?

What experiment would disprove Friedmann model of cosmology? As a layman, I have read a lot of articles and threads in specialized forums. I am probably wrong, but I developed an impression that that ...
6
votes
2answers
434 views

What experiments compete with BICEP 2, and when are their results expected?

The recent results of the BICEP 2 experiment published on March 17th 2014, has generated a lot of media attention, with the general consensus being that "this is a major discovery" perhaps leading to ...
72
votes
5answers
6k 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? ...
7
votes
1answer
154 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.
10
votes
9answers
2k 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 ...
1
vote
1answer
572 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 ...
20
votes
3answers
925 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 ...
4
votes
2answers
144 views

Cosmological triangle with PLANCK results

Is there an updated version of the cosmological triangle with recent PLANCK results included?
6
votes
2answers
371 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 ...
2
votes
1answer
213 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 ...
3
votes
2answers
415 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. ...
3
votes
1answer
178 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. Is this true? What could ...
5
votes
2answers
1k 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 ...
2
votes
2answers
127 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?
16
votes
5answers
575 views

What experiments, other than Hubble Expansion, support the Dark Energy theory?

Dark energy is introduced as a constant inside Einstein's equations. Its primary purpose, from what I understand, is to make Einstein's equations compatible with the accelerating expansion of the ...
5
votes
5answers
3k views

What is the evidence for Inflation of the early universe?

The theory of Inflation explains the apparent consistency of the universe by proposing that the early universe grew exponentially for a 1E-36 seconds. Isn't a simpler explanation that the universe is ...