Dark Energy, Dark Matter, and "Empty Space"

soyounoat

I'm new to this forum, and I've looked around but did not find this discussed. Apologies if I missed it.

Has anyone in the research of Astrophysics considered the "missing mass" of the Universe to be contained in the structure of space-time itself? Given a section of so-called "empty space" between galaxies with zero particulate mass, electromagnetic radiation (such as light) still has a speed limit. The propagation of energy across space, while very fast from out perspective, is ultimately frustratingly slow. We cannot even observe our own galaxy in it's entirety because the image of the other side is how it appeared 100,000 years ago. This soup of "empty space" that has an IMPEDANCE to electromagnetic radiation has got to be made of something. Is anyone with credibility addressing this in the Halls of Science today?

-soyounoat

mathman

An attempt at a physical explanation for dark energy is the energy of the vacuum. The problem with this attempt is that the vacuum energy would be 120 orders of magnitude too big.

RayYates

I've considered this myself and have looked into gravitation waves, dark flow, cosmic inflation and other subjects. I have not been able to completly dispel the notion. In fact I wonder if spacetime itself around galaxies is not spinning.

Observing other galaxies, they are spinning too fast and should fly apart. So Dark Matter was conceived to explain it. There was NASA experiment that proved that the spacetime around the earth is twisted "frame dragging" I think it was called. If a spinning Earth can warp spacetime, what affect would a spinning galaxy have on the surrounding spacetime after a 13 billion years or so?

twofish-quant

Yes. The problem is that dark matter appears to be lumpy. There's more dark matter in some parts of the universe than others. You can see this via gravitational lensing, and also via the lumpiness in galaxy distribution.

If you have something that is part of space time, then its hard to come up with lumpy stuff. If you assume that dark matter is some sort of heavy particle, then you can come up with lumpy galaxies pretty well.

One other possible candidate for dark matter is "alternative gravity" and that is something like what you are proposing.

They worked on this at the end of the 19th century. Look up lumeriferous ether and Michaelson-Morley. There are a lot of clever experiments you can do to look for this medium, and they have all turned up negative.

There are reasons why people think that EM just goes through empty space. If you have some sort of fluid that EM is going through then you ought to see scattering and lensing effects. Also something that is weird about light is that light always travels at the speed of light, which doesn't make sense if light is traveling through a medium.

twofish-quant

People did it at the late 19th century. Look up Michaelson-Morley experiment. To summarize. If light is moving though something, then you ought to be able to detect the motion of the earth through that something, and you don't. This confused people for a few years, until some guy named Einstein came up with an explanation for what is going on.

One thing problem with popular explanations of things is that they only mention the one explanation that seems to work. The don't mention the hundred or so explanations that people tried that didn't work. So the question of "have people thought of X" is usually "yes, people have thought of X, and it didn't work because......."

maddox210

Is it possible that dark matter works in an entirely different way than we think? Is it possible that dark matter actually decays into dark energy?

cristo

Sure, there has been a lot of work on this topic. See http://arxiv.org/abs/0811.0099 and references therein.

RayYates

I was thinking perhaps Dark Energy decays into space-time.

maddox210

How would one go about proving that? Could you perhaps start a private messages with me?