Do Dark Matter and Dark Energy Cast Doubt On the Big Bang?

StartsWithABang (3485481) writes "Back in the 1960s, after the discovery of the Cosmic Microwave Background, the Big Bang reigned supreme as the only game in town. But back then, we also assumed that what we consider as "normal matter" — i.e., protons, neutrons and electrons — was, along with photons and neutrinos, the only stuff that made up the Universe. But the last 50 years have shown us that dark matter and dark energy actually make up 95% of the energy composition of our cosmos. Given that, is there any wiggle room to possibly invalidate the Big Bang?"

Comments

Oh good lord.

[AdamColley]

There's always the possibility of a theory being falsified but in this case the answer is almost certainly no.

The big bang is not going to be invalidated, so say COBE, WMAP and PLANCK.

Also, it's actually less than 5% baryonic matter it seems, 4.4%

http://map.gsfc.nasa.gov/unive...

Be aware that dark matter is just matter we can't directly detect with our current technology (or just haven't /yet/), it's not something magical.

Re:Oh good lord.

[Opportunist]

And maybe dark matter isn't at all, but just a matter (bad pun, I know) of our misunderstanding of something.

Take the planet Vulcan. No, not THAT Vulcan. But also a fictional one. Astronomers noticed Mercury isn't circling the Sun as it should, so something had to account for this. In their understanding back then, there had to be another planet that causes that. But then uncle Albert came along and explained it with relativity and now we know that gravity is the culprit, not some planet we can't see.

What if this is a similar case? Like, say, (normal) matter having gravity properties that only become noticeable on a cosmic scale? Like, say, relativistic effects that take a DAMN LOT of gravity to become noticeable?

I'm not saying it is so, I just wonder if we're dead set on Dark Matter or whether we're actually still looking in other directions? Or rather, whether serious scientists actually look into different options aside of Dark Matter to explain the discrepancies, not just crackpots and snakeoil peddlers.

Re:Oh good lord.

[FireFury03]

Dark matter is probably just civilizations that have built (advanced forms of) Dyson spheres around their stars.
This also explains the Fermi paradox.

Dyson spheres would glow in the infrared and therefore be pretty obvious. This is because they still have to radiate the heat produced by the star they enclose - otherwise their internal temperature would perpetually increase.

Re:Oh good lord.

[AthanasiusKircher]

We just have no clue as to what it is or how it works.

I'd like to point out that gravity is in the same category. Also time.

This.

When Newton was first discussing his theories of universal gravitation, the scientific community was rather skeptical, because it invoked spooky "unseen forces" acting at a distance (i.e., gravity). The previous Aristotelean model of physics asserted that "normal" terrestrial matter came to a nature place of rest (earth sinks down to equilibrium, air rises to equilibrium, etc.), since Newton's first law hadn't been realized yet. Instead, real-world friction, etc. tends to bring things to a state of rest, which accords with everyday experience. All motion had to be explained by a "cause," something that propelled it into motion, and ultimately the matter would stop moving once it came to its natural state of rest.

The motion of the planets could not be explained using this physics, so the celestial bodies were assumed to be of a different type of aetherial matter (or something) which was set in motion at the beginning of time or something.

That was the proper scientific theory of the day, and it accorded with empirical observation and common sense -- terrestrial bodies stopped, celestial ones seemed to go in continuous motion forever.

But Newton came along and equated the two -- and he developed a mathematics that described the motion. Unfortunately it depended on a "spooky" occult idea of forces acting at a distance. (Newton, of course, was really into the occult, alchemy, etc.)

So, scientists of the day were skeptical. Newton eventually even published an appendix with future editions of the Principia explaining that his model didn't depend on "real" unseen forces acting -- instead, he basically came up with the modern scientific ideal that says: if the math works and predicts the phenomena, that's enough for science. A scientific model need not be concerned with philosophical questions or ultimate causes of phenomena as long as it can actually make good predictions.

THAT, probably more than anything else, was the foundation of modern "science" laid down by Newton during the Scientific Revolution. People had been doing experiments and empirical investigations for millennia, but they always had to worry about ultimate "causes," which inevitably depended on somebody's pet theory of reality. After Newton, though, what matters is that the math works. Maybe the dark matter/dark energy model is hinting at some deeper aspect of reality and a more elegant theory that we will come up with many years from now... or not. But regardless, these ideas are exactly like Newton's "gravity" -- something which we observe, something we can have an accurate mathematical model of, but also something "spooky" that we don't understand completely yet.

That's what the modern scientific process is all about.

Re:Oh good lord.

[Anonymous Coward]

A. What part of Gamow's ABC paper was "make theories to fit your observations"??

He published a paper on April 1st, 1948 with Ralph Alpher and Hans Bethe (Alphar - Bethe - Gamow... get it?) on Big Bang nucleosynthesis that explicitly stated that if there had been a Big Bang, that you still would be able to detect a black body radiation light curve from the first moments that the cosmos expanded (cooled) enough to allow photons to survive. Alpher soon calculated that the peek would be below 5 degrees by now.

Radioastronomers couldn't be bothered to check this out - it wasn't until 1964 that W&P (not radio astronomers) were trying to fix a "noisy" antenna that this was discovered. They got a Noble prize for this, which should have also gone to Alpher and Gamow.

B. That you say "And no, if you run that backwards it doesn't work out that its all in the same place." shows that you're thinking of the Big Bang as an explosion - as if you were observing it from outside. This isn't correct at all - everything you are, and the stars and galaxies are part of the cosmos. Two weeks ago - most galaxies were millions of miles closer - i.e. the cosmos was more dense. A few months ago - a few billion miles closer - more dense still. 13.7 billion years ago all the matter/energy OF the cosmos was so close - so dense and hot that there was a hot particle soup - that locally some galaxies are coming together due to gravity rather than spreading apart is irrelevant.

It's like saying - all the cars on the road couldn't be from a factory - they're all going different directions!

Re:Oh good lord.

[MightyMartian]

First of all, aspects of big bang cosmology were predicted before observation, and second of all, WTF? Theories have to fit observation or they are, by definition, wrong.

Re:Oh good lord.

[lgw]

Dark matter was there in todays proportions in the hot early universe, so no. All the MACHO theories went by the wayside with the CMBR data, it's WIMPs now for sure.

Re:Oh good lord.

[Aighearach]

That wasn't a person without a sparkler, that was a grue.

Don't ask me

[wonkey_monkey]

Do Dark Matter and Dark Energy Cast Doubt On the Big Bang?

I have no idea! You should probably ask a physicist.

Re:Don't ask me

[physicsphairy]

The physicists are the ones asking. We better take this one to the Big Guy Himself.

"So, uh, we were wondering if you could explain why our orbital and rotational predictions for galaxies are not matching our astronomical measurements?"

"They aren't? Are you sure? Let me check the source code. Oh, that's not good. Should have caught that a few billion years ago. This is going to be a real pain to patch. Unless. . . ."

"Unless, what?"

*lightning bolt strikes questioner*

Re:Don't ask me

[sound vision]

Perhaps that is the end goal of the "human experiment" - someone's trying to see how long it takes for a universe to evolve living beings, and for those beings to figure out the mechanics of their own universe. (Worshiping the creator is optional, but it probably gives him a giggle.)

This morning, I was reading about quantum phenomena and how some string theories posit that the length of a string is approximately the Planck length. Strings being the basic quantum unit, nothing can be measured to be smaller than 1 Planck length or measured with more precision than 1 Planck length. What you end up with then, is a universe where the spatial dimensions are a grid, that cannot be traversed continuously, but only in Planck-length increments. In other words - it is essentially digital. Like pixels on a display, where the pixels are much smaller than an atom. My understanding of string and quantum theory (admittedly far from complete) is that all aspects of the universe could be quantized, and thus simulated digitally in a computer.

If anyone can clarify/elaborate/refute, please do.

Oh good lord.

[Anonymous Coward]

Well, the fact that we can still hear the universe ringing at the exact range and frequency curve predicted by George Gamow nearly twenty years before Wilson and Penzias "discovered" it (see the cosmic background radiation - look it up), I'd say no.
Also, the farther out we look, the faster galaxies are moving away from us. Run that backwards in time and we're all in the same place about 13.7 billion years ago. Again, I'd say no.
Also, the balance of H, He and Li that was predicted...
Also, the evolution and make-up of stars and proportions of heavy elements in near and far galaxies...
Etc. etc.

Low Quality Article, Uses Question Mark.

[Anonymous Coward]

If a headline ends in a question mark the answer is always no. If the answer was yes they wouldn't ask, they'd tell.. The question mark is how shitty opinion pieces trying to push a view point try to masquerade as news.

Isn't it the other way around?

[dottrap]

I thought Dark Matter was conceived to account for missing matter that the Big Bang theory predicts needs to exist.

Re:Isn't it the other way around?

[Livius]

I thought Dark Matter was conceived to account for missing matter that the Big Bang theory predicts needs to exist.

No, it (mostly) came about when it was noticed that galaxies required a lot more mass than was visiible

It's both, and other observations as well. That's why dark matter is a good theory for the observations we have at this time - several phenomena all point to the same explanation.

Oh good lord.

[Anonymous Coward]

We're finding it quite easy to directly detect its affects with our current technology - it's called a telescope. We just have no clue as to what it is or how it works.
I'd like to point out that gravity is in the same category. Also time.
We do know a lot more about light and electricity. Please check out "QED" by Richard Feynman. Well we actually don't know how that works ether, but we've figured out the math to make very precise predictions that usually match reality so we must be on the right track.

Re:Dark matter

[Kjella]

As stated below by others, just because it's "dark" doesn't mean it's not just ordinary matter. It's just that we can't actually see it.

Repeating the ignorant doesn't make it true, that "dark matter" is simply ordinary matter we couldn't detect was a good first guess. Very strong evidence indicate it's not because that would create other interactions as well that aren't there. There's some small fraction that is regular matter and some is neutrinos, but without some other form of particles it just doesn't add up.

Dark matter and dark energy

[jd]

These theories have their own problems. As noted on Slashdot previously, neither exist around dwarf globular clusters or in the local region of the Milky Way. It is not altogether impossible that our models of gravity are flawed at supermassive scales at relativistic velocities, that there's corrections needed that would produce the same effect as currently theorized for this new kind of matter and energy.

Remembering that one should never multiply entities unnecessarily, one correction factor seems preferable to two exotic phenomena that cannot be directly observed by definition.

But only if such a correction factor is theoretically justified AND explains all related observations AND is actually simpler.

There is just as much evidence these criteria are true as there is for dark stuff - currently none.

Re:Oh good lady, and lord.

[Will.Woodhull]

we'd like to have non-baryonic fairly massive (so relatively cold) particles. Dark matter is anything that doesn't interact with regular matter via the strong or gravitational interactions. Neutrinos don't.

More and more I'm getting a feeling that science has been down this road before. That our understanding of subatomic particles and the distant edges of the Universe is similar to the pre-Copernican use of epicycles to understand astronomy. That the search for dark matter (and probably string theory too) is a search for that final missing epicycle that will make the model work just right.

I think we need to look for a Galileo or Copernicus who has some whacky, undeveloped alternate concept that if only we could change our point of view, we would see that it makes everything so much more clear.

The Bullet Cluster Makes it Unlikely

[Roger W Moore]

What if this is a similar case? Like, say, (normal) matter having gravity properties that only become noticeable on a cosmic scale?

Models like this have been considered such as MOND (MOdified Newtonian Dynamics). These models were largely shot down by the aptly named Bullet Cluster. This is a system of two galaxies colliding at a high relative speed. The gas from the smaller "bullet" cluster collides with the gas in the larger cluster causing it to slow down, heat up and emit X-rays so we can see it.

So far so go. However you can also look at the mass distribution by seeing how it distorts the light from galaxies behind the cluster (this is called gravitational lensing). This shows that most of the mass of the smaller cluster has not slowed down and is now separated from where all the gas in the cluster is located. Effectively the collision has separated the matter from the dark matter because, unlike normal matter, dark matter has a tiny cross-section for interacting with itself or other matter. This is exceedingly hard to explain by modifying the behaviour of normal matter since you are observing a gravitational field where there is no normal matter.

complete and utter rubbish

[thegreatemu]

I'm probably a bit biased here, but also an expert, since I am a physicist who studies dark matter for a living.

The title's question doesn't even make sense! Big bang theory, and in particular studying the exact power spectrum of the cosmic microwave background, is by far the strongest evidence we have for the existence of dark matter and dark energy. All those pie charts you've seen showing the divisions of baryonic matter, dark matter, and dark energy? If they're properly cited, I guarantee every single one of them comes from data from WMAP or PLANCK: CMB experiments! You can't say that dark matter gives you room to invalidate the big bang, because without that we don't have really any strong evidence for non-baryonic dark matter in the first place...

microwave bright [Re:Oh good lord.]

[Geoffrey.landis]

well, if Dyson spheres are anywhere near the size of the solar system, they would radiate in the infrared. Longer infrared the larger they are.

You could imagine a Dyson sphere that is vastly larger than a solar system -- like, a hundred AU across, or so--that would radiate waste heat in millimeter wave, or even something vastly larger than that that would radiate in microwave.

But, of course, that doesn't solve the problem-- they would be shine like beacons to radio telescopes.