Dark Matter

[Awaken4e1]

What do scientists look for when they search for dark matter? They cannot see or touch it...

[AirRick101]

They are constantly looking to find out if they can ever detect it. It's not an entirely hopeless venture, it could be thrilling. Note in mind that the greatest discoveries were done against the grain of society's opinions. We never know. I do the same thing and post a new thread on what I think might be an interesting topic. But your reputation here is not conducive yet to calm and collected discussion, I'm hoping to soften that blow.

[Awaken4e1]

Every little bit helps...

[Zero1328]

I think it's like how they search for black holes, they look for things that point towards the possibility of a black hole there.

[Awaken4e1]

So, they look for the effect of what they think is dark matter then?

[Roller]

More or less, yes.

[bradybaker]

Dark matter is observed by measuring the gravitational effects that it has on material and energy around it. Recently an entire dark matter galaxy was discovered.

[Awaken4e1]

Within a given number of galaxies the mass of these galaxies ‘flux.’ Thereby the gravitational stimuli is increased, and decreased within the fluctuation of their respective masses. Therefore the trajectory of these galaxies in relation to one another is altered within the respective distances of these galaxies, decreasing mass, and results in decreased interaction between the respective galaxies. And the increase of mass increases interaction between the given galaxies, and over a period of time these galaxies will increase their over all reaction speed by the increase and decrease of the gravitational force of their respective mass. Are the reaction of these respective changes in mass, and their related reaction the result of dark matter?

[bradybaker]

I wasn't aware that the mass of galaxies flucated...explain?

[Awaken4e1]

Within every galaxy the component stars are attracting, and expelling matter, within the respective galaxy, thus fluctuations in mass. That is if I am interpreting the data, correctly? Or, are these fluctuation the resulting effect of the force of dark matter these visible galaxies?

[dream-scape]

As already mentioned astronomers look for MACHOs (black holes, brown dwarfs, etc) by basically searching for gravitational anomalies. However, if the theory of dark matter is to be accepted, then MACHOs cannot account for all of the missing mass of the universe. So particle physicists look for WIMPs. WIMPs are smaller than atoms, thought to have mass, have a gravitational effect on ordinary matter, but be able to pass right through it. The way they are trying to detect WIMPs is that on rare occasions, since WIMPs can pass directly through matter, they will and interact with it when doing so. If you can witness one of those interactions, you have detected a WIMP. There are some large projects underway to attempt to do just this. However, to my knowledge, as of yet no WIMP has ever been detected. But not all scientists accept dark matter theory as an explanation for gravitational anomalies. Some suppose that our understanding of gravitation is incomplete or partially flawed and look for answers to the anomalies other ways. (whereas dark matter theory supposes our understanding of gravitation is absolutely correct and complete)

[Awaken4e1]

MACHOs = Massive Astrophysical Compact Halo Objects - black holes, brown dwarfs WIMPs = Weakly Interacting Massive Particles

[Awaken4e1]

Can anyone help understand these interaction?

[bradybaker]

Originally posted by Awaken4e1 Within every galaxy the component stars are attracting, and expelling matter, within the respective galaxy, thus fluctuations in mass. That is if I am interpreting the data, correctly? That affects the mass of the stars, not the galaxy as a whole.

[dream-scape]

Originally posted by Awaken4e1 Can anyone help understand these interaction? the interaction of a WIMP with normal matter? I think at the moment it is just a theory without any kind of real conclusive evidence, but I think the theory states something like on rare occasions a WIMP will hit a nucleus in a head on collision, which will cause the nucleus to have an elastic recoil, which we can observe [though we haven't really been able to yet]. http://physicsweb.org/articles/world/13/1/9 about 1/2 ways down under the section "How to detect a WIMP" it talks some about the theory of how WIMPs interact with matter.

[Awaken4e1]

Originally posted by bradybaker That affects the mass of the stars, not the galaxy as a whole. You can't effect one, without effecting the other as well...

[bradybaker]

Originally posted by Awaken4e1 You can't effect one, without effecting the other as well... The mass of the galaxy includes everything contained within its 'borders', it's not simply a sum of the masses of the stars. If the sun exploded tomorrow, you wouldn't subtract that mass from the Milky Way (cause you'd be dead, haha..moving on..) because the matter would still be present, just in the form of 'the Sun'.

[Awaken4e1]

I think I got it...It is the corresponding matter between the galaxies which is getting larger, and not the galaxies themselves, and it is not the increase of the component star matter even though their mass does increase, and decrease as the distances between these galaxies change. And it is these expansions, and increases of gravitational forces which is believed to be the reaction of dark matter within these galaxies. A mysterious repulsive force called dark energy accounts for 73 percent of the entire mass-energy of the universe, the (WMAP) Wilkinson Microwave Anisotropy Probe found; 23 percent consists of invisible dark matter, and only 4 percent of the universe is ordinary matter and energy. The Darkness is increasing

[AirRick101]

Not if you're going to keep that fire going.

[Awaken4e1]

[Oneironaut Zero]

Arise, ye old-ass thread!!! Proposed Dark Matter Ring, viewed by Hubble.

[joey11223]

wow that has to be the oldest bump of a dead thread i have ever seen!!:p ALso in that picture, what am i looking at, the gray smokey pattern right?

[LucidFlanders]

1 ring to rule them all, 1 ring to rule the universe. *fits on the ring* Hey, perfect fit! Anyway, looks like a ring. Those aliens are expierementing with things we cannot even dream about. Maybe they are trying to make their own dark matter universe.

[Oneironaut Zero]

wow that has to be the oldest bump of a dead thread i have ever seen!!:p ALso in that picture, what am i looking at, the gray smokey pattern right? That's a damn good question, actually. Haha. Judging by this quote: Dark matter previously has been detected in other galaxy clusters, but the scientists said the stuff never previously had been found to be so distinctly separated from the hot gas and the galaxies that make up these clusters. I'm thinking its the dark ring in the center of the haze, where it looks like there is nothing there. That's just a guess, though. Maybe someone here than knows more about space that I do (which isn't saying much, heh) could shed some light on it. ...no pun intended.