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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?"
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.
Do Dark Matter and Dark Energy Cast Doubt On the Big Bang?
I have no idea! You should probably ask a physicist.
systemd is Roko's Basilisk.
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.
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.
I thought Dark Matter was conceived to account for missing matter that the Big Bang theory predicts needs to exist.
I would say quite the opposite - that the existence of dark mater and dark energy suggests a possible mechanism for the initial rapid expansion (inflation) without resorting to "magic" forces we have not yet observed.
The electric universe or ionized plasma theory looks great on paper, but the cosmic scale currents and magnetic fields it describes would create easily detectable phenomena which are not actually observed.
I've personally observed a number of Christian astronomers cite "The Big Bang Never Happened", as possible testimony that the universe isn't 13.8 billion years old after all. Having actually read the book I enjoy pointing out that Eric Lerner's conclusion about the age of the universe being 150 billions of years old is completely out of wack with actual observations, and cherry picking parts of scientific ideas doesn't work the same way as cherry picking passages of other books. If your theory predicts things that don't match reality - throw it away and try again. Read up on dating quasars using spin decay rates if you really want to know.
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.
It's quite the opposite. You need dark matter and dark energy in order to explain the CMB and the distribution of matter in the Universe. Dark matter and dark energy fit perfectly in the theory, that's the main reason why the alternatives to dark energy/matter that have been proposed were rejected: they fail to explain the CMB and the distribution of matter, while the dark matter and energy explain it perfectly.
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 to keep from flying apart. The speeds of stars 'orbiting' was too high, and the things should have flown off. There were other oddities observed as well. All the behaviors observed could be explained if there was a lot more gravitational mass than what could be seen. Some of things seen were quite bizarre, too, and required the stuff to account for things acting the way they did.
Enter Dark Matter as a formal theory..
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.
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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.
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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.
Will
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.
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...
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.
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I believe that there is some wiggle room, looking at the electric universe theory.
Actually, Electro-Temporal Unification Theory shows that "electric universe" and "timecube cosmology" make the same predictions at the critical energy density point in 8-space, and is in good accord with all available evidence.
Unfortunately the paper was publised by a certain Jack N. Withya, so most cosmologists haven't bothered to read it.
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Part of the issue here is that the question is ambiguous. "Big Bang" has morphed and changed into may forms in the last century+ when it was first envisioned. So, which big bang are you and TFA referring to? The original that said all the mass was a few hundred thousand miles across and blew up? The one taught in the 1970s that all mass was compressed into a ball about 270,000 light years across and blew up? The one that still requires all of the mass to exist already and compressed down to a compact size that you can find on U of M website? Or finally, are you referring to the Big Bang which steals the Quantum/Expanding Vacuum theory, but somehow claims to still be a "big bang"?
QV or EV invalidates the need for a Big Bang. Though we don't know where quantum particles come from, the theory has worked out that collisions would result in mass over time and a constant source of energy. All we need to start the Universe is a small vacuum and time (hence the Universe is much older than people in the Big Bang camp claim). There are a couple variations of the QV/EV theory, but they don't differ greatly like the "Big Bang" does. I hate to advertise for the guy, but Lawrence Kraus's book "A Universe from Nothing" is a decent read.
As to this "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?" pardon me if I don't share your enthusiasm. From a logical perspective we have been able to study quite a bit of our solar system hands on, and we have never been able to detect either dark matter or dark energy (no, gravitational lensing is not a test [see last paragraph]). Even the people using the term in science papers can't seem to agree on any what these things are, properties vary from model to model and person to person.
Dense matter is a logical probability, because we know that the majority of every atom is empty space. Under extremely high gravitational fields this area could be reduced making denser atoms. Dark matter and dark energy have been used exclusively to make people's mathematical models of the Universe work. It is just as likely that we don't fully understand gravity as much as we thought, as it is to have dark matter and energy. I'd further argue that since we have never detected either in our solar system, odds would favor that they don't exist. I don't rule it out as impossible, but I would not say it's probable.
Gravitational lensing does not require either dark matter or dark energy. I find it odd that the NASA link discusses Einstein as the person that came up with the theory, yet fails to mention that Einstein did not theorize these two "dark" things. Gravitational lensing is a result of having curved space and obviously gravity. Dark * is not required nor expected..
-The wise argue that there are few absolutes, the fool argues that there are no probabilities.
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.
It's certainly possible that we're merely stumbling about to find a better theory, but I think the epicycles analogy is generally a bad one -- it was good science back in the day, based on what was "known" about the universe at the time. Now we know better, because we've figured out that some of the fundamental assumptions of the old model were wrong, but good scientists of the day had no way of knowing some of those things were wrong (and in fact had some good evidence that those things were right -- like a bunch of very logical arguments why the earth is not in motion and how various effects that should happen if it were in motion were not observed... most of those problems were only explained in the 1800s, centuries after Copernicus). (For detailed background on myths about epicycles, see here for example.)
Also, please note that Copernicus and Galileo both still required epicycles, since they presumed circular orbits. (Galileo rejected Kepler's correct empirical observations of elliptical orbits, since they weren't as "perfect" as the circle... which shows how far even great "scientists" of the day were invested in the old ideas.)
If anything, I think a better analogy for the kind of situation you're assuming in modern science would be with Galileo's theory of the tides, which he created even though it didn't make much sense (and didn't accord with empirical evidence -- it required only one tide per day at noon), but it allowed him to justify his heliocentric hypothesis. In effect, it was a whole new idea tacked onto the old models without empirical support and only needed to fill in the gap to "prove" that the earth was in motion (since other things needed the prove that hadn't yet been observed, and most wouldn't be until centuries afterward). In a similar way, trying to "prove" our newer Big Bang models and particle physics models has led to the introduction of dark energy, strings, etc.
Thus, dark matter/energy and string theory are similar new ideas built up out of the old ones to "fill in the gaps" as it were, and we don't yet know whether they will pan out. Epicycles, on the other hand, were a very old and extremely well-accepted idea (which both Galileo and Copernicus used in their theories).
Finally, I would also note that gravity too was a sort of "fudge factor" introduced by Newton without evidence: where does this "unseen force" come from? how is it transmitted? We still don't thoroughly agree on those answers, centuries later. But it made the math work out for Newton's idea of universal gravitation, just as some of our modern theories do today.
So the question is -- are these new ideas more like Newton's spooky occult theory of an unseen force acting at a distance, or more like Galileo's attempt to make up a theory of the tides to hold his model of the universe together? Only time will tell.