can dark matter be touched?

[spacefire]

I don't really understand what this talk about dark matter means. Is it an interstellar gas that absorbs light?<br /><br />would you be able to put it in a container and look at it absorbing light?<br />I just don't get it? <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[vandivx]

dark matter is a hypothesised extra matter which should be in galaxies to make their observed motion jibe with the observed matter that they contain<br /><br />galaxies rotate as if they had more matter than we observe in them and new unknown matter is postulated to exist (dark matter) to explain the increased galactic rotation (in its outer fringes) but nobody sees any extra matter there and nobody knows what it could be, just that it should be there<br /><br />it is sort of like in past atomic reactions didn't jibe (balance momentum/energy) and new particle 'neutrino' (little neutron) was postulated and everybody was looking for it untill it was found to exist and everything was ok again<br /><br />with dark matter we have many more candidates (possible solutions) than 'neutrino' and physicists are looking for all of them and for now untill the right solution is found the dark matter is a sort of collective name for all possible solutions<br /><br />perhaps better term than dark matter might have been unknown or invisible or undetectable matter but alas that doesn't have right ring to it <br /><br />but if you want to be ahead of everybody out there (except me of course) then be asured it can't be touched or smelled or bottled up <img src="/images/icons/smile.gif" /><br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[michaelmozina]

IMO you don't get it because "dark" things don't actually exist. Dark matter and dark energy are metaphysical constructs that "fill in the gaps" of standard theory but simply do not exist in reality IMO.<br /><br />http://www.cosmologystatement.org/<br /> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[h2ouniverse]

As VanDix points it, if dark matter exists, it does not interact with normal matter except by its own gravity.<br /><br />So ,you might have some going through you as you read these lines.

 

[michaelmozina]

<blockquote><font class="small">In reply to:</font><hr /><p>As VanDix points it, if dark matter exists, it does not interact with normal matter except by its own gravity. <p><hr /></p></p></blockquote><br /><br />Keep in mind that neutrinos certainly do interact with matter, albeit not frequently. We also know what a neutrinos is as it relates to particle physics, we know where it comes from, we know it's energy state and how to detect it.<br /><br />Compare and contrast that now with a metaphysical theory about something "dark", where nothing is known about it's energy state, it behaves as no other "particle" known in existence, nobody on planet earth can produce a single gram of the stuff, or any experiment to demonstrate it actually exists.<br /><br />The key word in your quote is "if", if dark matter (energy) exists.... At the moment they are metaphysical concepts with no physical definition, and there is no empirical evidence that they actually exist in nature. There is certainly no controlled experiment that demonstrates these things actually exist. That moves these ideas outside the realm of physics and into the realm of metaphysics <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[R1]

so are they more like free/lost/lose gravitons--more like a gravity law anomaly?<br /><br />maybe they're not so much like matter? I mean wouldn't they have also clumped up to form a planet or<br />star or something? <div class="Discussion_UserSignature"> </div>

 

[a_lost_packet_]

Dark matter, IIRC, is also supposed to be uncharged. That's why we don't see it radiating energy from reactions. But, to answer the question, "yes" it is theorized to be real and have mass. That is, after all, why it was theorized in the first place.<br /><br />Some pics of dark matter "maps" and an article on how they were made. http://news.bbc.co.uk/2/hi/science/nature/6235751.stm <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[jeffhannan]

'Observable' - when astronomers talk about observable are they just talking about stars?<br /><br />What about all the rocks? Aren't galaxies full of debris that can't actually be seen, but together adds up to a huge gravitational effect?<br /><br />Jeff<br />

 

[vandivx]

"What about all the rocks? Aren't galaxies full of debris that can't actually be seen, but together adds up to a huge gravitational effect?"<br />----<br /><br />LOL I knew somebody would ask as I wrote the word 'observable'<br /><br />it is not easy to describe ins and outs of this phenomenon in few words so as not burry people in long drawn out explanation<br /><br />all the 'debris' is accounted for, actually it doesn't amount to much I believe, it had been considered that there might be numerous brown dwarfs and immense gas clouds etc. out there in galaxies but the conclusion is there's not enough matter in that quarter, nevertheless I believe some scientists are still exploring that angle but aren't successfull in convincing their coleagues so far<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[ashish27]

Even the greatest of physicists don't have the answer to your question. They have "mathematically predicted" unaccounted mass influencing the behaviour of galaxies. They don't know where in the galaxy this kinda matter is stored or why they don't reflect light or emit any kind of heat or radio signature. They don't even know the properties of this kinda matter. Thats why they call it "dark". <br />I personally like to call it Ue matter, where Ue stands for Un-explained.<br />Nobody knows what will happen if human skin touches this kinda matter

 

[jeffhannan]

Thanks for the answer. <br /><br />You're not the only one using the word 'observable'. I've read quite a few articles on dark matter, and none have answered that obvious question.<br /><br />I could say that because the debris can't be seen, how can anyone judge how much it amounts to. There could be hardly any, or it might be clogging up interstellar space.<br />

 

[alokmohan]

Highly interesting question.I am impressed.Never thought it.But surely nobody knowsWe may research on it.

 

[qso1]

As has been pointed out already, dark matter is still a theoretical concept. However, if it exists...IMO it can probably be touched but we do not currently see it because the vast majoriy of the Universe is a dark Universe. No light to illuminate dark matter unless some of it is found within a light year or lkess of a light source such as a star. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[nexium]

Typical rocks have a density of two or three while stars have densities averaging 100 ? For the mass of rocks to exceed the mass of the visable stars, the transparency of the Universe would be reduced, more than what we think we observe, Thus we conclude the total mass of rocks is less than the total mass of visable stars. Mini black holes would not reduce the transparency of the Universe much, even if they out numbered the visable stars by a million times, but we should have found a mini black hole by now, if they are a million times more abundent than visable stars. Perhaps there are no miniblack holes. Neil

 

[heyscottie]

One of the many possibilities for dark matter includes some exotic material that interracts gravitationally, but not with light. This means that it does not ABSORB light, but rather is completely transparent to it. Anything that does not interract with the electromagnetic force would be invisible in the light spectrum. In addition, you could not "touch" it, either. The reason your butt feels the seat it is in and doesn't just slide through it is due to electromagnetic forces -- the atoms' electron clouds in the chair repels the atoms' electron clouds in your pants, not letting them pass through one another. Something that didn't interract electromagnetically could pass right through you more or less unnoticed, much like the neutrinos mentioned above.

 

[ashish27]

<blockquote><font class="small">In reply to:</font><hr /><p>Highly interesting question.I am impressed.Never thought it.But surely nobody knowsWe may research on it. <br /><p><hr /></p></p></blockquote><br /><br />Of course, we should <img src="/images/icons/wink.gif" />

 

[R1]

could dark matter just be non-interacting fermions? kind of like a noble gas cloud of an odd type of <br />a noble fermion? <br />the thing that makes me think the most is that we are rather inferring matter, and we maybe<br />should have stopped at inferring gravity, or at least paused a little longer?<br />After all, we don't really understand gravity completely yet, what if it's some kind of loose graviton or 'geon'?<br />or naturally occurring inert fullerene balls of otherwise non-interacting fermions?<br /> <div class="Discussion_UserSignature"> </div>

 

[ashish27]

it could be, it could be not. at the moment its all "dark" to physicists <img src="/images/icons/wink.gif" /><br /><br />(pun intended)

 

[alokmohan]

Nutrinos are dark matter .Every it touches us and vice versa.Agree?

 

[ashish27]

No. Neutrinos are not dark matter. they are a type of particle in their own right properties of which scientists already know. <br /><br />See we can't see neutrinos or they are hard to detect doesn't make them dark matter. Dark matter is a mathematical prediction and refers to matter that have not been detected by scientific instruments. Matter thats ghostly presence have left physicists "in the dark" is dark matter!

 

[alokmohan]

Is brown dwarf dark matter?

 

[ashish27]

No, brown dwarfs are failed stars. They are bodies of hydrogen with mass of about 80 Jupiters. Even if they don't emit light, the reflect the light of stars they orbit or thats near them. That prevents them from being dark matter. The wikipedia article has it all http://en.wikipedia.org/wiki/Brown_dwarf <br /><br /><br /><br />

 

[alokmohan]

http://physorg.com/news109658311.html.Excellent article in physorg.com.They have another candidate nutralino,produced at the time of big bang.The article is on dark world.96 percent not known.4% known stuff is matter.

 

[ashish27]

wow, highly interesting. thanks for the link.<br /><br />neutralino, hmmn, cool name <img src="/images/icons/cool.gif" /><br /><br />what other bookmarks do you have on dark matter/early universe?

 

[alokmohan]

And yet the galaxies were in close enough proximity to each other to conclude that they once has a dark matter halo to hold them together. To add more intrigue, there is an unusual concentration of dark matter halo in the main body of Abell 520 that, to error bars, looks like the missing dark matter that xould belong to the cluster that appeared to have lost its halo. But this, at least superficially, seems to suggest that some dark matter can indeed collide with something .Request elicit.