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Videos / Astronomy / Hubble Discovers Ring of Dark Matter







Hubble Discovers Ring of Dark Matter
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Hubble Discovers Ring of Dark Matter
An international team of astronomers using the Hubble Space Telescope has discovered a ghostly ring of dark matter formed long ago during a colossal collision between two galaxy clusters.


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Posted by nova on June 15, 2007
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Comments

Posted by John Q. Public on June 16, 2007 at 11:55 am
This is NOT evidence of "Dark Matter"!!

I was tempted to apologize for seeming to be so critical on this site recently, but the fact is that there has been a lot of material presented here lately that may not be what it seems on its face. It behooves a scientist to be skeptical and ask questions...

"Dark Matter", like "Dark Energy", have not been demonstrated to be real. In fact, they are mere hypotheses that are necessary in order for "String Theory" to work properly.

Let us just for the moment assume that this is an example of the String Hypothesis actually predicting the observed distribution of this matter, before it was observed. That would upgrade the String Hypothesis to an actual "theory" -- that is, if anyone can come up with a way to test it, which hasn't been done yet. BUT...

There is another hypothesis, or "theory", if this was actually a prediction, called Modified Newtonian Dynamics (MoND), that explains exactly the same phenomena quite well, WITHOUT the need for imagining bizarre things like dark matter and dark energy.

The old saying in science circles goes: "extraordinary claims require extraordinary evidence". And the very notion that our universe is made up mostly of dark matter and influenced by dark energy that we cannot directly observe, even with our modern instruments, is a pretty damned bizarre and extraordinary claim. To be honest, as far as actual evidence goes, it ranks right up there with the "theories" of "aether" and "phlogiston". The fact that a (very) complex set of mathematical equations, operating on a hypothetical set of 11 or so spatial and "timelike" dimensions, CAN explain this does not mean that it is the real explanation.

Because...

We have another "theory", which explains the same observations, that does not require the extraordinary claim that our universe is constructed mostly of things we cannot observe. Not only that, MoND has the advantage that it is a vastly simpler explanation than "string theory", so it also has Occam's Razor on it's side.

In any case, my simple summary reply to this video is: since multiple -- and even simpler -- "theories" can explain the same thing as observed here, this does NOT constitute "evidence" that dark matter exists. At all. Not even close. The presenters of this show CHOSE to explain the observation in terms of their pet "theory". Nothing more.
Posted by skywalker on June 17, 2007 at 1:22 pm
Scientific fact can be defined as the commonly accepted theory. Of course the theory of dark matter could be wrong (as with even the most fundamental assumptions of science) but there's a few flaws in your argument.

First of all, when you said: "We have another "theory", which explains the same observations, that does not require the extraordinary claim that our universe is constructed mostly of things we cannot observe." . I'd like to point out that we CAN observe dark matter, just not from the light reflecting off of it. To say that indirect observation is useless is to throw out a lot of modern science. Especially the discovery of extrasolar planets which is primarily done by observing by the gravitational effect of matter on a nearby object (the same method used to find the dark matter in the video).

The idea of Dark Matter is far from dependent on String Theory, even if String Theory is dependent on it. The universe doesn't require 11 dimensions for matter to absorb a wavelength of energy. Lead and other elements are great at stopping parts of the spectrum, why is it so far fetched that something could do the same to the visible light spectrum? You seem to be mistaking your complaint with the string theory for one with dark matter.

I have to do some reading on this MoND you speak of before I comment directly on it.

And in regards to your conclusion: Just because there are multiple explanations for something (even simpler ones) it does not necessarily invalidate the original theory. If you want to accept the simplest explanation you can find, here it is: God made a ring of interstellar gas so we could enjoy the beauty of it.
Posted by John Q. Public on June 18, 2007 at 1:47 pm
No, that is not a flaw in my argument, it is a flaw in yours.

We do NOT know that we have observed "dark matter". We have made -- as you accurately pointed out -- indirect observations that *have been attributed* to the presence of dark matter.

However, as I pointed out there are other HYPOTHESES (none of these, including string "theory", are technically "theories" until they can be tested via experiment), that explain the SAME indirect observations equally as well. So these same observations might be dark matter... or they might be, for example, a result of the actions predicted by MoND (the most popular alternative hypothesis).

I did not state that we did not make those indirect observations. or that they are not valid. I stated -- truthfully and accurately -- that there are alternative explanations for those observations, at least some of which are simpler than those which require the existence of "dark matter".

Further, I did not state that the existence of dark matter was dependent on string theory. Rather, I am well aware that string "theory" is dependent on it. "Dark matter" is a mathematical model that was dreamed up in order to make string theory work... not the other way around. The same is true of "dark energy". Therefore, it follows logically from your own statement that without string theory, there may be no need for any hypothesis of dark matter at all. And while dark matter may not require 11 (or so) dimensions, string theory certainly does.

And I was not "complaining" at all. I was simply pointing out a fact: When observations can be explained equally well by more than one hypothesis, as in this case, that observation does NOT preferentially support either hypothesis. Therefore, at this time this observation does not constitute evidence for the existence of "dark matter", much less a confirmed observation of same. That was an assumption by the presenters, no more.

To address your last point: I did not claim that any theory was invalid, I simply pointed out that Occam's Rasor would seem to favor MoND. However, I am well aware that Occam's Razor is only a platitude; it proves nothing.

Do not make the logical error of assuming that simply because I pointed out an alternative, I must be on that "side". Not at all. I am an open-minded skeptic. If someone can show me convincingly that string "theory" is somehow preferable to others, then I will gladly jump on that bandwagon. However, so far that has not been done. In the meantime, I will continue to point out alternatives that may seem preferable in a number of ways.
Posted by John Q. Public on June 18, 2007 at 2:18 pm
I like to make one more point.

You made the statement: "Scientific fact can be defined as the commonly accepted theory." And I have heard or seen that comment made quite a bit recently. But only recently. It used to be otherwise.

While it certainly CAN be defined that way, I would strongly caution against it. And I make that statement for the best of reasons.

The entire history of science -- all of it -- is the story of new and upstart ideas turning accepted theories on their heads. EVERY major scientific advance has involved invalidating, to some degree, what was commonly accepted before.

Over the last couple of decades, I have watched scientists and even whole disciplines become increasingly entrenched, supporting their favorite and "accepted" theories while deliberately and forcefully rejecting new ideas out of hand. And that, friend, is not Science. After a time, it starts to resemble something more like religion.

If we arbitrarily refused to consider alternative ideas, however wild they may appear at face value, simply because they did not follow "commonly accepted" ideas or theories, then we would voluntarily be giving up any right we may have had to be calling ourselves scientists, and any right to claim we were following the Scientific Method.

It does not get much simpler than that.
Posted by skywalker on June 18, 2007 at 5:07 pm
" "Dark matter" is a mathematical model that was dreamed up in order to make string theory work. "

This is completely incorrect. "Fritz Zwicky used it for the first time to declare the observed phenomena consistent with dark matter observations as the rotational speeds of galaxies and orbital velocities of galaxies in clusters, gravitational lensing of background objects by galaxy clusters such as the Bullet cluster, and the temperature distribution of hot gas in galaxies and clusters of galaxies."

And in regards to occam's razor favoring the MoND theory, dark matter would be simpler because it requires fewer changes to established scientific theory.
Posted by John Q. Public on June 20, 2007 at 3:38 pm
I am aware of this history. My statement about the origin of the dark matter postulate might have been incorrect (I am not convinced but it may be so), but that is irrelevant to the discussion. The relevant point here was that string theory is dependent on the existence of dark matter, and not the other way around.

Quote from Wikipedia (and I can find similar quotes from a plethora of sources): "String theory remains to be confirmed. No version of string theory has yet made an experimentally verified prediction that differs from those made by other theories."

Regardless of the above, the fact is that exactly the same gravitational "anomalies" that were observed in the rotation of galaxies, which stimulated the idea of dark matter, are also explained my MoND and other hypotheses, which do not require us to imagine that the universe is made up mostly of things that are unobservable. The idea that most of the universe cannot be directly observed is a rather extraordinary claim (as I mentioned in the beginning), which therfore requires extraordinary evidence... which has so far not been forthcoming. At all. None of the "evidence" obtained so far supports the idea of dark matter any more than it supports those other hypotheses.

Further, since MoND requires nothing but slight adjustment of the numbers in some existing theories, MoND so far remains the simplest explanation that works. By quite a long way.
Posted by John Q. Public on June 21, 2007 at 6:45 am
Pardon the typos. That should have been: "None of the "evidence" obtained so far supports the idea of dark matter any more than it supports those other hypotheses."
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