Could anything be made out of dark matter?

[Wowbagger]

At least in theory? Or, is use of the word "matter" deceptive in that regard?

If so, would something made out of dark matter inherently last longer (perhaps be less prone to the effects of entropy, etc.) than anything made out of ordinary matter? (I doubt it, myself, but if anyone can offer specifics, that would be nice.)

What would be some of the properties of dark-matter-based objects, that would be considered "exotic" next to ordinary matter objects?

I ask because I am in the midst of reading this gawd-awful excuse for a science fiction book, in which the author seems to take great satisfaction in abusing the mysterious nature of this stuff; and I would like to know a little more about it, before I develop a rebuttal.

Thanks!

 

[Delvo]

Atoms, molecules, and things made out of atoms & molecules stick together because of electromagnetic interactions (emission & absorption of photons). Dark matter doesn't have electromagnetic interactions (doesn't emit or absorb photons). So it can't stick together in atoms or molecules, nevermind anything bigger like a planet or a speck of dust.

 

[Illustronic]

It is the existence of true nothing to inhibit matter from effecting other matter.

That's my uneducated theory about it, the only true vacuum.

 

[tensordyne]

wiki: "In astronomy and cosmology, dark matter is matter that is inferred to exist from gravitational effects on visible matter and background radiation, but is undetectable by emitted or scattered electromagnetic radiation."

So I guess DM is a form of matter that would just sit there (given you figure out some force of nature to use to hold it together) that would not shine or be reflective in any way. Kind of like that movie "The Sphere", I think it was called. Maybe DM also causes you to go insane and make your worst fears and most ecstatic joys come to life in a horrifying undulation of incessant, unending and unnerving action packed fun! -- or not.

 

[wollery]

At present our best guess at the properties of Dark Matter is that it only interacts via Gravity. I say guess, because we don't actually know what the hell it is. It appears to reside in and around concentrations of baryonic matter, but is far less clumpy, because it doesn't have any of the other forces to make it stick together in smaller concentrations.

Of course, it's entirely possible that Dark Matter has some properties that baryonic matter doesn't have, so we'll just have to wait and see.

 

[temporalillusion]

A black hole, that's about all I can think of.

 

[Slimething]

http://shrinkingjeans.net/2010/02/hersheys-dark-products-review/

 

[bokonon]

The frame that holds our galaxy together is reputedly made of dark matter.

According to Morgan Freeman's new "Through the Wormhole" series, when galaxies collide, the everyday matter's momentum is mutually mashed, while the dark matter goes sailing blithely on as though there had been no collision at all. I wonder if this would lead to a new composite galaxy in which stars closer to the center would rotate about the center of the galaxy faster than stars farther away. Or to a galaxy which wouldn't hold together at all. Or whether the composite undarked galaxy would eventually attract enough dark matter in its cosmic rainbarrel to be like all the other galaxies.

 

[arthwollipot]

I think the only possible answer to this question is "we don't know yet".

 

[Dats]

Juice

the darker than matter the sweeter the juice

 

[Dancing David]

The frame that holds our galaxy together is reputedly made of dark matter.

According to Morgan Freeman's new "Through the Wormhole" series, when galaxies collide, the everyday matter's momentum is mutually mashed, while the dark matter goes sailing blithely on as though there had been no collision at all.

Sort of ,sort of not, there are not the immediate visible 'collisions' but the dark matter will respond gravitationally. Therefore depending upon the vectors the DM can be bound to the common center of gravity (as it were), so while the tidal arms and distortions of galaxy 'collisions' (which basically pass through each other and interact mainly through gravity), are visible, the DM gravitational interaction are not visible yet they are there. The DM does not carry on in a straight line forever, depending upon the masses and vectors it can be bound to the system.

 

[Cuddles]

At least in theory? Or, is use of the word "matter" deceptive in that regard?

No. There's nothing deceptive about the word "matter", it's just that it's a kind of matter that you really can't make things out of. You can't make things out of neutrinos either. They're still very much matter, they just don't interact with other matter strongly enough to form a static structures.

Of course, it depends exactly what you mean by "made" and "anything". Since dark matter does interact through gravity, it can of course form gravitationally bound systems. In fact, that's exactly what we see - dark matter forms disks and halos on a galactic scale. So if all you mean by "make anything" is "manipulate it so it forms a big, hundreds or thousands of light years across blob where we want instead of where it was to start with", yes, it's possible in theory. If you mean something more like building computers or bombs or spaceships or something, no.

If so, would something made out of dark matter inherently last longer (perhaps be less prone to the effects of entropy, etc.) than anything made out of ordinary matter? (I doubt it, myself, but if anyone can offer specifics, that would be nice.)

No. As far as we know, dark matter is just made up of particles that only interact through gravity. There's nothing magic about them that means they don't obey thermodynamics, they just happen not to interact with things through the other three forces.

What would be some of the properties of dark-matter-based objects, that would be considered "exotic" next to ordinary matter objects?

They wouldn't have any properties because they don't exist. The big rarefied blobs would just have a gravitational pull, that would be exactly the same as any equivalent baryonic mass. But the dark matter spaceships, or whatever, simply don't make sense as an idea, since you're really going to struggle to build a spaceship that's only held together by gravity.

 

[edd]

It's worth pointing out that we're optimistic it might do something other than just gravitate. If it just very rarely happens to bounce off ordinary matter through some mechanism, that'd be quite handy for those people trying to detect it in Earth-based facilities.

Of course, very rare interactions aren't good enough for actually building things.

 

[bokonon]

Sort of ,sort of not, there are not the immediate visible 'collisions' but the dark matter will respond gravitationally. Therefore depending upon the vectors the DM can be bound to the common center of gravity (as it were), so while the tidal arms and distortions of galaxy 'collisions' (which basically pass through each other and interact mainly through gravity), are visible, the DM gravitational interaction are not visible yet they are there. The DM does not carry on in a straight line forever, depending upon the masses and vectors it can be bound to the system.

As your quotes around "collisions" indicate, the ordinary matter is not actually colliding either; like the dark matter, it is responding gravitationally to the mass in the colliding galaxies. I believe the dark matter itself was being detected by gravitational lensing of more distant light sources, and though as you say it may be interacting, it doesn't seem to be slowed as much as the ordinary matter.

You say it doesn't continue on forever, so does it eventually drift back into the combo-galaxy? Or do we not know yet?

 

[Wowbagger]

But the dark matter spaceships, or whatever, simply don't make sense as an idea, since you're really going to struggle to build a spaceship that's only held together by gravity.

How did you know it was a spaceship I was referring to?

 

[Aitch]

But the dark matter spaceships, or whatever, simply don't make sense as an idea, since you're really going to struggle to build a spaceship that's only held together by gravity.

Couldn't you trap the DM in a matrix of some other substance? Not sure why you'd want to, though.

 

[Myriad]

I have a dark matter door stop.

It's great. Since it only interacts gravitationally, it holds my door open but you can't trip over it. http://www.darkmatterdoorstops.com

Respectfully,
Myriad

 

[Ziggurat]

Couldn't you trap the DM in a matrix of some other substance?

Well, if it only interacts via gravity, then the only trap you could make is a gravitational trap. And you can't make complex structures with a gravitational trap.

 

[DeiRenDopa]

If it turns out that dark matter does have some non-gravitational cross section (i.e. it interacts, albeit fleetingly, with baryonic matter, or with itself), then things like dark matter stars might be possible.

The universe seems to have succeeded in building 'something' with dark matter ... galaxy halos, filaments, sheets, and, in between them all, voids. Trouble is, these are somewhat larger than country mansions, planets, and HII regions.

 

[Wowbagger]

Thanks, everyone, for your replies.

Am I to assume then, that the idea of building an "everlasting" spaceship out of dark matter is completely and utterly in the realm of complete fantasy, just as I feared?