Comments on: New Study Finds Clumps and Streams of Dark Matter in the Milky Way

By: Prathapan

Prathapan — Sun, 10 Aug 2008 07:17:51 +0000

Arun Prabhu,
Lets us have your knowledge in short.

By: Donna Greven

Donna Greven — Sat, 09 Aug 2008 20:53:32 +0000

As I said in an earlier article yesterday, about dark matter/energy being the "stuff" that happens between the time the light from any given object leaves its source and the time it reaches us, especially up to 13.7 billion years, cannot EVER be seen by us, even though we can detect its effect upon the universe. A lot of, as yet, unseen matter and energy can be created in that time. As I am not a mathmetician or have the means or resources, would anyone care to test that theory and either post it or do an article on it? Thank you.

By: Al Hall

Al Hall — Sat, 09 Aug 2008 03:23:53 +0000

Arun Prabhu -
Then post your theory… Here.

By: Feenixx

Feenixx — Fri, 08 Aug 2008 19:36:26 +0000

@Barbara
they can't tell us what happened 13.7 billion years ago

rather: using what we have observed to-date, they can help us build a model of what happened.

We can then use the model to help us explain what we observe in the future… until we observe something we cannot explain – then we need to make a new model

Actually: weather forecasters often use supercomputer models, made from whatthey have observed to-date, attempting to predict the weather

By: Barbara

Barbara — Fri, 08 Aug 2008 16:49:07 +0000

I don't get it. Super computers can't predict the weather for tomorrow yet can tell us what happened 13.7 billion years ago!

I guess the difference is no one was there to prove them wrong!

By: Arun Prabhu

Arun Prabhu — Fri, 08 Aug 2008 11:38:17 +0000

Hi, All Hall
Even I don't believe in nothing…..i am not talking about nothing here…something else and about that 'something'

By: Al Hall

Al Hall — Thu, 07 Aug 2008 23:42:48 +0000

Arun Prabhu –
Let's hear the short version… Its not about the mystery of the "space mirrors" is it?

Of course sims are good, but as some have said above ^, the computer will only make conclusions based on the criteria input. Anyway…
I for one don't believe in "nothing". I don't believe in "empty" space. I think that everything (that we are conscious of) is made of 'something'. Even if we can't see it or detect it. Does this undetectable "stuff" (possibly less than sub-atomic particles that have yet to coalesce) affect the behavior of detectable objects? Maybe but I'm not convinced.
Another thing…. The Big Bang happened and the universe is expanding, right? What is in front of the matter that has expanded the furthest? Nothing?… It can't be nothing. If it was nothing, if there was "nothing" there… it doesn't exist, therefore it would be impossible for our "universe" to expand there. You can't put something into nothing… If I were standing on the outer edge of our universe and looked outward, what would I see? Nothing?… If I see a black void, then that is "something".. Not nothing.
I don't believe in nothing….. We still have a lot of work to do to understand what is really going on… I think DM/DE is just a phase we are going through… I just hope we get some really cool answers before I die… Hey, who knows? Maybe it is all about the mysterious space mirrors!!……………… Nah……

By: Excalibur

Excalibur — Thu, 07 Aug 2008 22:53:58 +0000

Simulations like this are not performed to draw conclusions, they are done to get a better view on what to expect if the underlying hypothesis is correct.

I am fairly sure this simulation was not set up with a starting point choosen to give the results it did. If anyone could predict the end results from the initial conditiones beforehand, they most likely carry more computational power in their heads than this computer could do in a year.

By: szanne

szanne — Thu, 07 Aug 2008 21:37:09 +0000

agreed

By: Arun Prabhu

Arun Prabhu — Thu, 07 Aug 2008 21:13:50 +0000

I have answer for some part of dark matter mystery.Based on that I can justify lot of secrets of the universe.In our day today life we experience the effect of dark matter !!

How to publish my article?

By: Ayti

Ayti — Thu, 07 Aug 2008 19:06:50 +0000

The computers involved were designed for just such purposes and so this was not a waste of resources – simply a use of them.

Perhaps the article headline leads to unwarranted conclusions but I doubt that was the intent of the authors of the study – who did not write the news story or the headline.

The simulation produced testable predictions. Assuming GLAST is able to detect gamma rays at the appropriate energy/ wavelength we should soon have observations that test these predictions.

By: curtis

curtis — Thu, 07 Aug 2008 18:13:12 +0000

better than 80% of the Universe' mass is "dark matter". Dark matter has had the definition of "non-baryonic" matter, or to the laymen, matter we cannot observe directly. Not a good way of puting it, since baryonic matter can still be dark. it is only visible if it either emits it's own light, or reflects light from an emitting source.

My biggest question is why the assumption that this is non-baryonic? We call it dark matter because we cannot see it, but know it is there based on it's gravitational effects. Could it in fact be baryonic matter that is too small / distant to observe directly. Every day we learn that space is not the empty vacuum we once thought. Thousands of objects exist in our own heliosphere, but I cannot see them. we know they are there though. Could the unaccounted for mass be from planets and asteroids not visible due to distance from a light source?

I may be wrong, but experience and common sense has indicated that the simplest explanation is usually the correct one. Think back to some of the math problems we used to do back in grade school. I saw some of them make the "smart" kids look pretty dumb. Add to that, 2000 years of science has brought us to the point where the earth is once again the center of the universe, I just think we're impressed with our own collective intelligence, and over-complicating the situation. Anyone else agree?

By: John Mendenhall

John Mendenhall — Thu, 07 Aug 2008 16:35:35 +0000

Quote from Neoguru:
"Add my name to those expressing concern that sumulated results are often stated in headlines as factual. The practice is very common and misleading. However, it was an interesting article."

Good summary of something seen all too often, even here on BAUT. Add my name, too.

By: DrNecropolis

DrNecropolis — Thu, 07 Aug 2008 15:59:05 +0000

Personally I believe computer modeling and simulations are some of the most useful tools in our scientific arsenal. That is of course assuming that you are building your sim from the bottom up, that is your end assumptions aren't built into your models design. As long as you understand the limitations of your model it can be extremely helpful, just don't run around saying , "Well my model proved it so it must be true", that's just plain irresponsible.

By: Dark Gnat

Dark Gnat — Thu, 07 Aug 2008 15:49:10 +0000

Yeah, simulations are bad. Flight simulators, CAD, and anything that uses computers to model reality or theory is bad.

In fact, maybe thought experiments and theoretical mathmatics should be abolished, because they are all a waste of time too.

Maybe we should shut down all IR, UV and X-ray telescopes, because we can only see optical light, and the other stuff isn't really there, because we can't directly see it.

By: Astrofreak

Astrofreak — Thu, 07 Aug 2008 15:38:24 +0000

Utter nonsense once again. So, somebody wrote a "simulation" purporting to analyze something we don't know much of anything about, they then "ran" their simulation and now we have more "evidence/proof/indications of" whatever.
Thanks for the waste of bytes.

By: Dark Gnat

Dark Gnat — Thu, 07 Aug 2008 15:27:53 +0000

From the outside looking in, it's easy to criticize and call the efforts of others a waste of time.

Strangely, none of the critics have anything better to offer.

If dark matter theory is wrong, then it's wrong. But in order to know whether it is wrong, scientific method has to be applied.

By doing these simulations, researchers can get a better idea of what to look for in reality. If they find it, great, if not, then theories are revised.

That is how it works. There is no failure as long as something is learned.

The greatest minds of history were almost always ridiculed by their peers, often because their peers simply didn't like the ideas presented by those great minds.

It is better to search for years and be wrong, than to never search at all.

By: Peter K

Peter K — Thu, 07 Aug 2008 15:20:16 +0000

I'm with neoguru. And please people, realize that we have to do the best we can with the data at hand. If those early map makers hadn't honed their craft with inaccurate drawings, many would not have had the courage to pit ship against waves. We have to start somewhere but by your logic, we should all stare at our navels as we're really not that sure about anything else!
In this day and age of information, we can explore the universe with more than ships and telescopes.

By: neoguru

neoguru — Thu, 07 Aug 2008 14:59:34 +0000

Add my name to those expressing concern that sumulated results are often stated in headlines as factual. The practice is very common and misleading. However, it was an interesting article.

By: RL

RL — Thu, 07 Aug 2008 14:48:54 +0000

Oops, I meant to say:
Running the simulation based on a hypothesis is only a waste of resources if the test results are NOT tested against.

Still haven't had that second cup of coffee.

By: RL

RL — Thu, 07 Aug 2008 14:47:52 +0000

Running the simulation based on a hypothesis is only a waste of resources if the test results are tested against. Hopefully someone can use GLAST to test their conclusions. (I think I answered my own earlier question). I don't remember seeing this in the article, but I'd be interested in knowing if the simulation predicted DM densities where current observations show that DM should be.

By: Ignoramus

Ignoramus — Thu, 07 Aug 2008 13:22:27 +0000

Agreed with Wes Lambert.
If you can set the parameters of a simulation, you can prove anything.
What a waste of resources!

By: Luke Coulson

Luke Coulson — Thu, 07 Aug 2008 12:58:47 +0000

Sorry, so what I meant to say was, "why bother starting your simultion, with a self fulfilling prophesy"? I do love a good simulator though. Innit?
P.S. Does anyone have a view about "electrical discharge machining" on a planetary level and the scalar ramifications elswhere manifest?

By: Luke Coulson

Luke Coulson — Thu, 07 Aug 2008 12:53:27 +0000

It may be that the cosmic background radiation purported to be resultant from the beginning of the (then) known universe, could still could feasably be attributed to, that "big bang" (beginning of the (now) known universe), yet may still prove to be just the "local event" to which I, a participant in, infinity, have previously alluded to and which I elect to percieve the flows and eddies of the plasma and other standing waves on the infinite superfluid.

By: RL

RL — Thu, 07 Aug 2008 12:15:14 +0000

Simulations are fine but the results they produce need to be tested and verified. For example, simulation of what goes on inside of stars tell us what we should observe being emitted. That can be observed and the correctness of the simulation can be verified. It doesn't seem from the article that this kind of comparison (against observations) has happened yet. A good start though.

Does anyone know of plans to do this?