Comments on: Dark Matter is Denser in the Solar System

By: Scott

Scott — Fri, 21 Nov 2008 21:04:45 +0000

Can black matter be the remnants of a black hole? If black matter does exist, it's obvious that its mass must be significant.

By: RedSparrow

RedSparrow — Tue, 15 Jul 2008 17:05:51 +0000

Astrofreak, this is for you:

http://www.youtube.com/watch?v=wKjxFJfcrcA

By: Bill

Bill — Sun, 06 Jul 2008 22:22:53 +0000

It looks like the material referred to as normal matter is not what is normal for matter in the universe.

Guess it's too hard to change now. People got real upset about Pluto so I can guess the level of outrage that would occur if astronomers said we humans are not made of normal matter.

By: Lightning Bug

Lightning Bug — Sat, 05 Jul 2008 00:28:48 +0000

Observations may be consistent with there being at least two distinct but related forms of matter.

The first and most interesting being as described by Newton and an apple falling to Earth; the material of which we are all composed.

The second being locked to the structure of the universe but attracted to the mass of freely moving bodies; resulting in a pucker or concentration of the raw universal mass.

By: Tyler Durden

Tyler Durden — Fri, 04 Jul 2008 17:46:47 +0000

^^ Was that in English?

By: Richan

Richan — Wed, 02 Jul 2008 16:48:25 +0000

It is mean we are going to changes and changes,because everything must be "alive".
We wait but not afraid ,we dare because some one care.
Count the date until we dead,and than we will relize that we still alive.

By: bob

bob — Sun, 29 Jun 2008 02:34:08 +0000

Cookie Monster,

No. Einstein's general relativity does not fail to predict expansion of the universe at all. It does predict it and Einstein thought that the universe was static and only introduced the cosmological constant to fudge up GR and make it fit a static state.

By: Chuck Lam

Chuck Lam — Sat, 28 Jun 2008 18:50:51 +0000

To Ed2, I did the math based on the most current theories surrounding dark matter and it appears the density to be about "one of something the weight of a proton" in every cubic mile at sea-level. This seems like a lot of matter for this small a cube, but that's what the math is showing. Considering what we are looking for, I don't believe we have anything that can detect this "something" called dark matter if it actually exists.

By: Astrofreak

Astrofreak — Sat, 28 Jun 2008 17:08:44 +0000

Oh man, there isn't enough time in a lifetime to begin even talking abot what crap all the "dark matter'" theories are. Of course there has to be dark matter [dark energy, worm holes, gravity waves et. al] because are theories tell us they are needed and lots of science classes, textbook sales, grants and careers are at stake. Hmm, the world used to be flat, earth was the center of the universe and atoms were indivisible. Oh yeah, don't forget the ever popular "expansion of the universe is speeding up!"

By: bob

bob — Sat, 28 Jun 2008 16:06:18 +0000

DM cannot be electon neutrinos because it does not move at relativistic speeds. The only way neutrinos could be DM would depend upon the possible existence of primordial degenerate neutrinos gathering at the galaxy clusters' center of masses. Degenerate matter puts up a fight against against gravity in the case of white dwarfs and neutron stars and while it can shake at relativistic speeds, it is unlikely displaced through space relative to matter at relatvistic speeds. They are locked at energy levels that they cannot rise and fall from, disabling them to give off light or interact with it. Do degenerate neutrinos fail to oscillate? Is this their form of locking? Do they group into a mass that moves slowly? More experiments are needed to verify this.

Science is not based upon finding rock solid truths. Science does not seek the truth. Science is based upon falsification that realizes beliefs that are less false. This makes science dynamic. Seeking truth is to seek absolutes and absolutes are brick walls that attempt to resist change.

The CMB shows spots at the center of masses of galaxy clusters where photons from the CMB are being scattered. When one crunches out the numbers one can calculate the amount of mass that does the scattering and it comes to about 3 to 4 times the mass of all the visible matter in the cluster.

Independently, if one uses X-ray telescopes and aims them at those spots, one sees X-rays emitted from each of them caused by neutral hydrogen that has gravitationally clustered and is colliding at those spots, emitting the X-rays we see. One can observe the change in the amount of X-rays across each of those regions to calculate the amount of mass of neutral hydrogen responsible for the emissions and they match the calculations in the preceding paragraph….3 to 4 times the mass of the visible matter in the cluster.

However, it is still not enough to account for the rotation curves observed. DM is simply the best of the competition right now. Even Jacob Beckenstein, a member of MOND, had to introduce DM and DE in order to make sense of the MOND hypothesis. The whole reason MOND formed was to disprove the existence of DM and DE so Beckenstein's publication simply enraged many who then broke off and formed a spinoff called MOG.

The only way a ne

By: Ed2

Ed2 — Sat, 28 Jun 2008 11:36:01 +0000

Ethan Siegel:

Assuming your speculation is correct, can you estimate the density of dark matter at sealevel on planet Earth? Do you think/believe that dark matter are elctron-neutrinos?

By: quantum_flux

quantum_flux — Fri, 27 Jun 2008 19:28:58 +0000

Ethan Siegel,

I am curious if dark matter interacts at all with regular matter in terms of electromagnetic or nuclear forces. Saying it is the local dark matter in our solar system is some 16,000 times denser than the background dark matter leads me to believe that there should be some other up-close forces involved besides just gravitation because something must be responsible for the capturing mechanism (or perhaps the dark matter energy is redshifted by the expansion of the universe and thus is captured).

By: Chuck Lam

Chuck Lam — Fri, 27 Jun 2008 19:12:17 +0000

To James, Yes! I am having fun with science. Hmm . . . didn't Einstein admit he was wrong abour a few astrophysical things? Also . . . isn't the "big bang" just another abstract thought in an infinite number of theories? To R2K, Keep in mind that speculation is among the first steps of progress. .

By: Tyler Durden

Tyler Durden — Fri, 27 Jun 2008 18:27:24 +0000

"R2K, if you think about it, dark matter makes a little more sense than just saying 'I'll invent something out of the blue' I mean, if the mass is there, but you can't see it, matter that only reacts gravitationally makes sense. It solves several problems, so they're trying to prove it now."

In a way it is the most plausible theory, at least in the framework of multiple dimensions beyond the 4 measureable in spacetime.

It's entirely possible that the majority of the mass in the universe exists solely in the other 5-7 dimensions (depending on who you ask) and can only interact with the observable universe through gravity.

But there's still too many variables that are entirely unknown (and unnamed) in this situation and until they can pin at least some of them down it's more practical to simply refer to the issue as "missing mass" just as everyone used to do.

By: James

James — Fri, 27 Jun 2008 16:52:26 +0000

I think Graham said some pretty important words.
Chuck, are you an astrophysicist? Since you posted the theory here, I'm going to assume you're not. Your theory, while interesting, could possibly already be disproved with things we already know. Things that make logical sense to you usually don't work out in the real world of physics, unless you're Einstein.
Sure, you completed step one of Graham's scientific method, but can you do the rest? Throwing out random hypotheses is really just having fun with science. There are approximately an infinite number of theories like that. "Maybe we're wrong and it's actually…" Yeah, maybe.
R2K, if you think about it, dark matter makes a little more sense than just saying 'I'll invent something out of the blue' I mean, if the mass is there, but you can't see it, matter that only reacts gravitationally makes sense. It solves several problems, so they're trying to prove it now. Really, that's all science has ever been. It's never been 'rock solid.' Since when wasn't it speculation on things we simply don't understand yet?
Basically, there are some pretty fundamental flaws in physics as we know it. Dark matter solves some of those issues better than just about every other theory (except maybe string theory, which is more like a belief than a science?). I think researching more into dark matter is a good idea. If you don't, you'll need to say a little more convincing argument than 'I don't think it's real.' Because it could be.

By: CookieMonster

CookieMonster — Fri, 27 Jun 2008 16:39:56 +0000

I agree with R2K. Didn't Einstein come up with the "cosmological constant" to explain why his relativity theories didn't work set against an expanding universe?

Dark matter / energy is a fudge theory, because we don't have any other explanations for something we don't understand.

It's also very comforting to know that we don't understand everything, and that there are fundamental parts of fabric of the universe which are completely unknown.

The laws of physics are not complete yet.

By: R2K

R2K — Fri, 27 Jun 2008 15:15:11 +0000

So sad to see astronomy go from very elegant and rock solid work on the nature of stars and the evolution of the universe… to lots of speculation on things we simply dont understand yet. Speculation is great, but people are way too confident in their work sometimes.

Something isnt rotating the way it should? Invent something called dark matter that must be there, rather than saying "We dont understand this. We dont know yet. Lets keep trying."

Having said that, if dark matter is real, that mass makes it sound like comets are to blame. Thus dark matter, and dark energy (comets pulling probes in the direction of the oort cloud) are caused by comets. QED and Quid Pro Quo.

By: Tony Trenton

Tony Trenton — Fri, 27 Jun 2008 13:48:49 +0000

All +ve energy is attractive. This is fundamental.

Everything is scaleable from infinitely small & dense to infinitely large & rarified & every condiion in between.

All +ve matter are condensed portions of the overall Electromagnetic field. Created during the early moments of the Big Bang.

The dark energy IS the overall rarified Electromagnetic field.
If this became matter it would no longer be dark!

Gravity waves are the variations in the density of the EMF on a very large scale.
Such as those delineated by the spiral arms
of galaxies.

Tthis is consistant with the nature that we observe.

There are two fundamental forces:

The Electromagnetic and Turbulence

That is all we nead .

By: Chuck Lam

Chuck Lam — Fri, 27 Jun 2008 12:41:26 +0000

Dark energy, dark matter or the something out there we really don't understand may be stuff of the "big bang." Forget the math and paradigms for a moment. The BB could simply be dark energy morphng or condensing in some strange way into possibly dark matter which in turn morphs into the visible universe over a lengthy period of time. This morphing, for lack of a better word, BB could be going on right now on a time scale we can't measure. The classic BB theory of matter "bursting forth in an instant from a small point" may be totally wrong.

By: Don Cox

Don Cox — Fri, 27 Jun 2008 11:59:48 +0000

The distribution of Dark Matter seems to closely match that of Stupidity.

Could they be the same thing?

By: Graham

Graham — Fri, 27 Jun 2008 09:13:07 +0000

Yes, that's the point about science and the journey from hypothesis to theory – and the aspect that politicians and others get wrong. In science we start with a hypothesis. It accumulates evidence and the probability of it being correct is seen to increase. We start to talk about "belief" in the theory. We never mean belief in a religious sense (ie that perceived probability never equals 1); there should always be that pinch of salt. The ability to behave as if a theory were correct, but at the same time have a gremlin sitting on one shoulder whispering "rubbish, this is a house of cards" is critically important. Quite difficult to square with a public desire for certainty and a successful career in science though – groupthink can be powerful.

By: LBFay

LBFay — Fri, 27 Jun 2008 02:39:48 +0000

JamesB, it's reminding me to Darwin's theory of evolution (or I should say "hypothetic"?)

By: JamesB

JamesB — Thu, 26 Jun 2008 20:51:48 +0000

Dark matter isn't even a theory, it's a hypothesis which makes it not just uncertain but unlikely to exist.

It's one attempt to explain certain phenomenon that has been observed but not understood. The more phenomena the hypothesis explains the closer to a theory science gets. And the more complete the explanation provided by the hypothesis, the closer to a theory science gets as well.

Anything you see on the subject of dark matter at this point in time is "hypothetical" and not "theoretical", and although entertaining should be taken with a grain of salt.

By: John Mendenhall

John Mendenhall — Thu, 26 Jun 2008 20:33:55 +0000

LDIAZ, the notorious 'picture' is of where the dark matter has to be, if there is such a thing, to produce the observed lensing. It is NOT a picture of DM.

By: One Skunk Todd

One Skunk Todd — Thu, 26 Jun 2008 20:26:01 +0000

Professor Farnsworth uses it to power starship engines.