Theory Posits Early Stars Powered By Dark Matter

ethericalzen writes "A BBC article highlights a theory that the first stars may have been powered by dark matter. A group of US scientists published a paper in Physical Review Letters speculating that, unlike the stars of today, which are powered by nuclear fusion, early stars might have been powered by the abundant dark matter crowding the universe after the Big Bang. The theory suggests that these stars would have collided and destroyed one another before nuclear fusion had a chance take hold." The BBC perhaps overstates the certainty with which the dark-matter theory is held, and doesn't mention that the postulated properties of such particles are completely speculative.

Comments

Dark Stars?

[ArcherB]

Maybe that's where all that Dark Energy came from.

Overstates?

[moderatorrater]

How do you overstate the certainty of dark matter? Last I read, the only serious alternatives were that there's more interstellar dust than we thought (improbable considering the observations of the bending of light), modifications to the theory of gravity (few supporters, unlikely, especially with said observations), and string theory.

Re:Overstates?

[John Hasler]

> How do you overstate the certainty of dark matter? Last I read, the only serious
> alternatives were that there's more interstellar dust than we thought...

That doesn't work because you can't get the observed distribution with baryonic matter.

Re:Overstates?

[_KiTA_]

Or, perhaps, modifications to theory regarding the nature of space itself. But why muck up a perfectly good theory based on observation of reality? Seems counterproductive to me.

Re:Overstates?

[mark-t]

Actually, it seems to me that the universe expanding completely uniformly in higher dimensions than what is visible would still explain all of the non-uniform expansion that dark matter was apparently invented to explain. It baffles me as to why they would invent the notion of something invisible to explain anomalous observations instead of going with a no less workable and radically simpler theory.

Re:Overstates?

[shma]

Other alternatives being explored generally rely on alternatives to General Relativity (for instance, TeVeS) to describe results that are attributed to dark matter. I was actually at a day of seminars at the Perimeter Institute last fall where Katherine Freese gave a talk on this subject. The next speaker was actually talking about alternatives to GR and offered an interesting analogy. Early on, when astronomers were still mapping out the solar system, they noticed that Uranus' orbit did not conform to what was predicted by Newtonian gravity. As a result, they predicted a 'dark' body farther out who's orbit was influencing Uranus. This turned out to be Neptune. On the other hand, the precession of the perihelion of Mercury, which was also believed initially to have been caused by an unseen planet (which they called Vulcan), was found to be the result of the failure of Newtonian gravity, and is now seen as confirmation of General Relativity. He concluded that both avenues of enquiry are valid and should both be followed.

Re:Overstates?

[Btarlinian]

How do you overstate the certainty of dark matter? Last I read, the only serious alternatives were that there's more interstellar dust than we thought (improbable considering the observations of the bending of light), modifications to the theory of gravity (few supporters, unlikely, especially with said observations), and string theory. I think kdawson meant that they were overstating the certainty of this theory, not the existence of dark matter in general. To be honest, I'm not sure why there are so many people (at least on /.) who want to relegate dark matter the the mathematical physics bin along with string theory. There's plenty of evidence for it. We've even observed gravitational lensing from dark matter. Dark energy on the other hand, may be something of a luminiferous aether.

Re:Overstates?

[mark-t]

We had already accepted that there were more than 3 dimensions anyways.

Re:Overstates?

[Sanat]

"makes their existing theories still work without being forced to confront the possibility that we really don't have a clue about anything."

Most of the theory right now revolves around our solar system and what occurs there. We have a whole set of formulas to calculate it.

But those formulas fall apart when applied to the very small such as an atom so we make exceptions.

Each planet rotates a given speed based upon its distance from the sun, yet electrons do not follow that same calculation around the proton.

Also now science is seeing that the Galaxies in space are rotating in a manner that also defies their calculations. A galaxy rotates all together nor like our planets whizzing at different speeds causing retrogrades and etc.

There is much to discover and we live at the opportune time to assist in these understandings of how the universe is really designed. We have chosen the perfect time to be here on Earth!

Re:Overstates?

[techno-vampire]

Each planet rotates a given speed based upon its distance from the sun, yet electrons do not follow that same calculation around the proton.

And that, of course, is for a very good reason: the electrons aren't in orbit around the nucleus in the same way that the Earth is in orbit around the Sun. If they were, electro-magnetic attraction would pull them into direct contact almost instantly.

Thanks, kdawson

[NereusRen]

The BBC perhaps overstates the certainty with which the dark-matter theory is held, and doesn't mention that the postulated properties of such particles are completely speculative. Aside from the actual topic, I want to say that I was pleasantly surprised to see the summary correcting for the improper journalism of the article. Overzealous interpretation of scientific results by journalists is a common complaint around here, and our editors who know that (and can easily recognize it when they review the submission) are the perfect ones to catch the inaccuracy and notify us in advance, so we aren't mislead about the actual claims of the scientific paper. Thanks, kdawson, for the excellent editorial addition to this story.

Re:Light from nothing?

[4D6963]

How can something so dark create so much light...

First off, dark matter isn't dark but transparent. Then, how could say methane and oxygen which are transparent create light when burning together? Oh I know! Maybe that's because it's not the matter that releases light/energy but its transformation.

sure they were

[pha7boy]

everything is explained by dark matter. Universe heavier then we think it should be? dark matter. can't figure out the big bang? dark matter. I bet soon enought someone will figure out a way to tie dark matter to the cables in the middle east that got cut the other day.

I figured this out several years ago...

[3waygeek]

after all:
1. Nibblonian civilization predates the Big Bang by 17 years.
2. Nibblonians poop dark matter.

Ergo, the first stars were made of Nibblonian poop.

Re:Your tax dollars funded this, but no article

[red_pete]

Here's the LANL preprint: http://arxiv.org/abs/0802.1724v2

Are they still stars?

[smackenzie]

Don't we have a pretty concrete definition of what a "star" is? If these early objects were actually composited of dark matter, wouldn't they be something else?

For example, a tennis ball and a "tennis-ball-shaped" object made of iron are two very different objects. I know which one I would like to have hit me in the head.

Dark matter is an optimization?

[BLAG-blast]

If this was a simulation, would you simulate very atom? Or would you bulk compute matter that was less important, until it became important then simulate every atom?

Could dark matter, or matter we have trouble seeing, be the equivalent of hiding polygons which don't need to be rendered in a 3D scene?

Geez, I hope not. Quick, prove me wrong.

Re:Dark matter is an optimization?

[Anonymous Coward]

More like a bad simulation.

You can't get your galaxies to meet project specs, so you fudge your algorithm and hope the teacher doesn't notice.

Re:Dark matter is an optimization?

[Planesdragon]

Geez, I hope not. Quick, prove me wrong. Ok. If we were a simulation, and were simulating only the important stuff, that simulation would include the appearance of particles far off in the light-cone. To our PoV, it'd be as if they were actually always simulated.

Re:Light from nothing?

[MikeDX]

Actually.. methane and oxygen are colourless... My physics teacher practically beat us to death with that one.

Re:Light from nothing?

[SlashWombat]

Dark matter stars make BLACK LIGHT?

Re:Maybe a better word

[dgatwood]

PC Guy: Hi, I'm a hypothesis.

Mac Guy: And I'm a theory.

PC Guy: Wait a second, how did you become a theory all of a sudden? What, you think you're special now?

Mac Guy: No, it's not that, P.C. I just got promoted because so many new people like me.

PC Guy: So because a lot of people like you...

Mac Guy: Well, and it also helps that I've been subject to a lot of scrutiny and they've concluded I'm not full of holes...

PC Guy: I resemble that remark....

Mac Guy: I know you do, P.C. And, of course, a preponderance of evidence confirms my correctness and robustness. That's one more reason that they made me a theory.

PC Guy: Preponderance of evidence... kind of like the O.J. Civil Trial, then?

Mac Guy: ...

PC Guy: ...

Mac Guy: Okay, I'm just going to have to go with "yes" and we'll call that your best hypothesis....

[Apple logo]

Re: Very Very Dark Matter

[Dice]

That's not accurate, there is much evidence supporting the idea of massive particles which do not interact via the electromagnetic, strong, or weak forces. There is, for instance, the observation of lensing in the Bullet Cluster last year which put to rest many of the modified gravity theories. There is also the recent observation reported earlier on /. of a galaxy composed of stars whose motion can be described without dark matter. The latter observation is particularly damning, if the effect were due to a misunderstanding on our part of the gravitational force or some quantum mechanical property of normal matter then it should be seen everywhere.

Re:Your tax dollars funded this, but no article

[moderatorrater]

Physical Review is edited and typeset by elves And that's just the beginning. Care to see how far down the rabbit hole goes?

Re: Very Very Dark Matter

[lgw]

There is zero evidence of Dark Matter. Circumstantial but it's just like string theory: a lot of take, no proof. There's as much evidence for dark matter as there is for black holes or neutron stars or anything else in cosmology that we can't actually visit.

Dark Matter was just one hypothesis among many for why galaxy rotation wasn't as expected until we started getting the very precise measurements of the cosmic microwave background radiation a couple of years ago. That made it clear that the matter mass of the early universe was about 80% non-baryonic, reacting to gravity but not light pressure. The percentage and distribution was predicted well by a dark matter theory, and it has explained some later observations as well.

Re:Light from nothing?

[thrillseeker]

Actually.. methane and oxygen are colourless... My physics teacher practically beat us to death with that one.

Didn't see it coming?