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3
votes
2answers
131 views

“Dark” quantities

I don't know much about the so-called dark matter, apart from what has been described in popular descriptions of the reasons for it being postulated. My question is, is there dark momentum, dark ...
5
votes
3answers
385 views

Could the acceleration of universe expansion be caused by gravity itself?

Dark energy is suggested to be a repulsive force in the universe causing an accelerated expansion. If the amount of mass outside our observable universe is greater than inside (higher mass density), ...
2
votes
0answers
126 views

Dark-energy sources and respective implications

Firstly, I want this to be a very layman/simple level. According to Sean Carroll, we have certain possibilities for where dark-energy comes from: http://www.youtube.com/watch?v=v6o2bUPdxV0 ...
8
votes
1answer
38 views

New Type of Type Ia supernova. Implications to Dark Energy measurement?

As I understand it, we used Type Ia supernovas to determine that there is some sort of repulsive force (which we call dark energy) making things fly away from us at an accelerated rate. The reason we ...
2
votes
0answers
217 views

Why do galaxies collide? Reconciling dark energy and an expanding universe with the fact that some galaxies are on a collision course

My layman understanding of cosmology is: galaxies are uniformly (more or less) spread throughout the universe, per the Big Bang and the fact that in a central explosion, all dispersed points are ...
-4
votes
2answers
215 views

Could dark matter be expanded atoms, and dark energy expanded radiation? [closed]

After watching Lawrence Krauss' lecture 'life, universe, and nothing', an interesting idea lighted up in my mind. Is it possible that dark matter is just spread out matter waves and dark energy ...
1
vote
1answer
29 views

Could dark energy be linked to dark flow?

I couldn't find any other questions regarding dark flow on Wikipedia, so I'm curious. As far as I can tell, dark energy's existence seems to be hard to explain. Since there may be a couple of ideas ...
4
votes
2answers
747 views

When will the Hubble volume coincide with the volume of the observable Universe?

The Hubble volume is the volume that corresponds to objects so far from the Earth that the space between us and them is expanding faster than the speed of light. (I.e. objects outside this volume ...
-4
votes
3answers
3k views

Is the Keppe Motor “real”?

Its makers say that it's a highly efficient motor because it resonates with (what they call) "Essential Energy", which is free energy that is everywhere in space. (I think that’s just a different name ...
4
votes
4answers
232 views

Could dark energy be the effect of gravity at great distances?

This may be a silly question, but is it possible that dark energy and gravity are related to each other? Space-time is deformed everywhere in space by objects with mass. The more massive the object, ...
14
votes
3answers
2k views

What is Dark Energy, and how was it discovered?

I've heard a lot about Dark Energy, and how it's supposed to be one of the most powerful forces in the universe. What is it, and how was it discovered?
0
votes
1answer
582 views

Lawrence Krauss' Theory of Origin

I don't understand how a vacuum, the absence of matter, can hold energy. How can it hold energy when Einstein proved that matter is energy? And a second related question; how does the energy in a ...
26
votes
4answers
865 views

Are modified theories of gravity credible?

I'm a statistician with a little training in physics and would just like to know the general consensus on a few things. I'm reading a book by John Moffat which basically tries to state how GR makes ...
8
votes
5answers
580 views

Dark matter and dark energy references

I've been looking for questions about dark matter, and I've read some very interesting answers. However, I desire too look into it deeply. This is not actually a question. I'm asking the community ...
3
votes
2answers
268 views

asymptotic curvature of the universe and correlation with local curvature

There is not-so-rough evidence that at very large scale the universe is flat. However we see everywhere that there are local lumps of matter with positive curvature. So i have several questions ...
16
votes
5answers
574 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 ...
-3
votes
1answer
1k views

Dark energy converted to electricity [duplicate]

Possible Duplicate: Dark Energy saving the world In theory, dark energy be used to generate electricity. Given its apparent abundance, this could provide rather a lot (perhaps too much) ...
5
votes
3answers
384 views

What current alternatives are there to the standard concordance model of cosmology?

The current "standard model" or concordance model of cosmology is Lambda CDM which includes late time acceleration due to a cosmological constant, cold dark matter as the missing matter component and ...