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Author Topic:   Dark matter a dying theory?
Theodoric
Member (Idle past 11 days)
Posts: 7051
From: Northwest, WI, USA
Joined: 08-15-2005


Message 16 of 113 (619118)
06-08-2011 3:44 PM
Reply to: Message 15 by tesla
06-08-2011 3:14 PM


Re: Not so fast....
Please explain your point here.
I have an idea where you want to go with this, but I am not sure if I am imagining it or if my fears are correct.


Facts don't lie or have an agenda. Facts are just facts

This message is a reply to:
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Replies to this message:
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Taq
Member
Posts: 8445
Joined: 03-06-2009
Member Rating: 7.4


Message 17 of 113 (619122)
06-08-2011 4:54 PM
Reply to: Message 15 by tesla
06-08-2011 3:14 PM


Re: Not so fast....
You know, It could be a problem with the math.
Let's examine this posibility as well:

Lat's say a spinning mass is off balance. take a beach ball, and in the center attach a metal core, one half iron, the other half aluminum. In a free spin (in space), will it travel?

I am assuming that you are referring to the spin rates of galaxies. If not, then the rest of this post will be more for general knowledge.

The first hint that dark matter existed was that galaxies were spinning too slow as measured by the luminous mass of the galaxy. However, this isn't the only evidence for dark matter. Gravitational lensing offers the best evidence for dark matter. We know from relativity that mass distorts spacetime, therefore dark matter should do the same even if it does not reflect, absorb, or emit light.

Secondly, dark matter does not seem to interact with luminous matter, something akin to neutrinos. This is why dark matter is often referred to as WIMP's (weakly interacting massive particles).

The perfect place to put these two characteristics to the test is in galactic collisions. When two galaxies collide the luminous matter interacts. This slows the luminous matter. However, the dark matter does not interact and moves right through. This should leave 4 different areas of mass, two for luminous matter from each colliding galaxy and two further away on each side for the dark matter. So how do we look for these areas of mass? Gravitational lensing of light from background galaxies. So what are the results? Exactly as predicted. The picture below maps the luminous matter in red and the dark matter in blue:

Read more here:

http://www.msnbc.msn.com/...ic-collision-reveals-dark-matter

So not only is the math correct, we can now map the distribution of dark matter around galaxies. I would say that dark matter is not a dying theory.


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 Message 15 by tesla, posted 06-08-2011 3:14 PM tesla has responded

Replies to this message:
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tesla
Member (Idle past 285 days)
Posts: 1199
Joined: 12-22-2007


Message 18 of 113 (619123)
06-08-2011 4:54 PM
Reply to: Message 16 by Theodoric
06-08-2011 3:44 PM


Re: Not so fast....
No real point other than what is stated. I’m aware that for every action there is an equal and opposite reaction. So if a massive earthquake, or an asteroid impact can modify the behavior of a mass, a solar flare could move a star etc., then perhaps the behaviors are being affected by interaction forces (unseen matter in a standard sense) instead of invisible matter.

Or maybe the unseen matter is just too small to see, like a group of asteroids.

Or again, our math could just be wrong. The greater the distance the greater the difference a small mathematical error can show (i.e. if you measure a 6 ft. line--next to a 6 ft. wall--and are off an inch the first foot, the difference at the end will be 6 and a half inches, with a line length of 6 ft. and 1/4.)

It could just be variations in spins and balance because the 'evidence' is strong for spiral galaxies.

I'm simply suggesting there are other possibilities besides invisable matter. I'm not a scientists, so You can take what ya want or leave it all at that.

Edited by tesla, : added a wall. hey, maybe I'll make a room out of it.


keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
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Replies to this message:
 Message 19 by Taq, posted 06-08-2011 4:58 PM tesla has responded

  
Taq
Member
Posts: 8445
Joined: 03-06-2009
Member Rating: 7.4


Message 19 of 113 (619125)
06-08-2011 4:58 PM
Reply to: Message 18 by tesla
06-08-2011 4:54 PM


Re: Not so fast....
No real point other than what is stated. I’m aware that for every action there is an equal and opposite reaction. So if a massive earthquake, or an asteroid impact can modify the behavior of a mass, a solar flare could move a star etc., then perhaps the behaviors are being affected by interaction forces (unseen matter in a standard sense) instead of invisible matter.

How does this produce gravitational lensing of light?

Or maybe the unseen matter is just too small to see, like a group of asteroids.

This would dim the light coming from background galaxies which would be detectable. Dust particles much smaller than asteroids blocks our view of our own galactic core (which is very bright), as a counter-example.

It could just be variations in spins and balance because the 'evidence' is strong for spiral galaxies.

Again, this does not explain gravitational lensing where no luminous mass is observed.

I'm simply suggesting there are other possibilities besides invisable matter. I'm not a scientists, so You can take what ya want or leave it all at that.

Those other possibilities have to take all of the observations into account, not just the spin rate of galaxies.


This message is a reply to:
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Replies to this message:
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tesla
Member (Idle past 285 days)
Posts: 1199
Joined: 12-22-2007


Message 20 of 113 (619127)
06-08-2011 5:07 PM
Reply to: Message 17 by Taq
06-08-2011 4:54 PM


Re: Not so fast....
"Some theorists have suggested that rather than invoking dark matter, perhaps existing ideas about gravity might be wrong. Maybe gravity is stronger on intergalactic scales than what is predicted by Newton and Einstein."

From the article.

Also: "all astronomers agree that dark matter is such an exotic idea as to border on the crazy."

Also: "It is still possible there is some modification of gravity going on"

This to me is propaganda; scientists have to believe in dark matter to have funding for science in their field.


keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 17 by Taq, posted 06-08-2011 4:54 PM Taq has responded

Replies to this message:
 Message 23 by frako, posted 06-08-2011 5:29 PM tesla has acknowledged this reply
 Message 24 by Taq, posted 06-08-2011 5:30 PM tesla has responded

  
tesla
Member (Idle past 285 days)
Posts: 1199
Joined: 12-22-2007


Message 21 of 113 (619131)
06-08-2011 5:22 PM
Reply to: Message 19 by Taq
06-08-2011 4:58 PM


Re: Not so fast....
You know, light can do some funny things, because it will take the quickest path. We can only guess at what is between us, and what we are looking at over very long distances.

http://astro.berkeley.edu/~jcohn/lens.html

"There are ongoing searches to use lensing to find a type of dark matter called MACHOs (massive compact halo objects). Although MACHOs, as dark matter, cannot be seen themselves, if they pass in front of a source (e.g. a star nearby), they can cause the star to become brighter for a while, e.g. days or weeks. This effect has been observed, but determinations of the dark matter are not yet conclusive."


keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 19 by Taq, posted 06-08-2011 4:58 PM Taq has responded

Replies to this message:
 Message 22 by Taq, posted 06-08-2011 5:25 PM tesla has responded

  
Taq
Member
Posts: 8445
Joined: 03-06-2009
Member Rating: 7.4


Message 22 of 113 (619132)
06-08-2011 5:25 PM
Reply to: Message 21 by tesla
06-08-2011 5:22 PM


Re: Not so fast....
You know, light can do some funny things, because it will take the quickest path. We can only guess at what is between us, and what we are looking at over very long distances.

We don't have to guess. We can directly measure it. When measured, light is being bent by gravity produced by non-luminous mass.

"There are ongoing searches to use lensing to find a type of dark matter called MACHOs (massive compact halo objects). Although MACHOs, as dark matter, cannot be seen themselves, if they pass in front of a source (e.g. a star nearby), they can cause the star to become brighter for a while, e.g. days or weeks. This effect has been observed, but determinations of the dark matter are not yet conclusive."

How does this explain the observations made in the bullet clusters discussed in my post above?


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 Message 21 by tesla, posted 06-08-2011 5:22 PM tesla has responded

Replies to this message:
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frako
Member
Posts: 2925
From: slovenija
Joined: 09-04-2010


Message 23 of 113 (619134)
06-08-2011 5:29 PM
Reply to: Message 20 by tesla
06-08-2011 5:07 PM


Re: Not so fast....
Scott Dodelson and former Brinson Fellow Michele Liguori demonstrated one of the first pieces of theoretical evidence that an alternative theory of gravity can explain the large scale structure of the universe.

So by your conspiracy theory these guys where not funded but forked own their own cash for their research ?

Science isnt a religion where you have to believe in a particular fictional character if you want to be in their club. You can even attack evolution if you do it scientifically and if you win fame glory and fortune await you


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Taq
Member
Posts: 8445
Joined: 03-06-2009
Member Rating: 7.4


(1)
Message 24 of 113 (619135)
06-08-2011 5:30 PM
Reply to: Message 20 by tesla
06-08-2011 5:07 PM


Re: Not so fast....
This to me is propaganda; scientists have to believe in dark matter to have funding for science in their field.

False. Scientists have to back their claims with evidence. Period. Scientists who claim that dark matter exists have backed this claim with experiments and evidence. What is not tolerated is people sitting in the back row taking potshots at a theory they never intend to test.

If anything, scientists who vehemently disagree with the current consensus are more strongly tolerated within science than in other professions. Fred Hoyle was famous for staunchly rejecting the Big Bang theory, yet he was kept around just because he disagreed. More importantly, Hoyle at least tried to produce a competing theory. He was wrong, but at least he was spectacularly wrong.


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 Message 20 by tesla, posted 06-08-2011 5:07 PM tesla has responded

Replies to this message:
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tesla
Member (Idle past 285 days)
Posts: 1199
Joined: 12-22-2007


Message 25 of 113 (619137)
06-08-2011 5:55 PM
Reply to: Message 22 by Taq
06-08-2011 5:25 PM


Re: Not so fast....
I'm simply pointing out that light can be tricky. All our stellar observations are of very old light (distance of a million light years means we see what that looked like one million years ago, not in current time)

There was a phenomenon of an iceberg appearing to fly. The light was following the fastest path to the observer and appeared in the sky instead on the ocean where it was, out of view of the observer.

I'm saying: nobody truly knows, and there are still a lot of other potentials besides invisible matter to explain the behavior. We don't know, everyone is guessing.


keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 22 by Taq, posted 06-08-2011 5:25 PM Taq has responded

Replies to this message:
 Message 27 by Taq, posted 06-08-2011 6:01 PM tesla has responded

  
tesla
Member (Idle past 285 days)
Posts: 1199
Joined: 12-22-2007


Message 26 of 113 (619139)
06-08-2011 5:58 PM
Reply to: Message 24 by Taq
06-08-2011 5:30 PM


Re: Not so fast....
False. Scientists have to back their claims with evidence.

And so far they have failed to do that. Many scientists see what they want to see. It doesn't mean there are no other explanations.

The data has to be interpreted. It doesn’t mean initial interpretations are correct.


keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 24 by Taq, posted 06-08-2011 5:30 PM Taq has responded

Replies to this message:
 Message 28 by Taq, posted 06-08-2011 6:03 PM tesla has acknowledged this reply

  
Taq
Member
Posts: 8445
Joined: 03-06-2009
Member Rating: 7.4


(1)
Message 27 of 113 (619140)
06-08-2011 6:01 PM
Reply to: Message 25 by tesla
06-08-2011 5:55 PM


Re: Not so fast....
I'm simply pointing out that light can be tricky. All our stellar observations are of very old light (distance of a million light years means we see what that looked like one million years ago, not in current time)

Every single observation we make anywhere is of old light. You seem to be throwing up arbitrary distances so that you can ignore the evidence.

I'm saying: nobody truly knows, and there are still a lot of other potentials besides invisible matter to explain the behavior. We don't know, everyone is guessing.

Scientists aren't guessing. They are creating hypotheses and testing those hypotheses (the bullet cluster example I mentioned is a perfect example). So far, dark matter has passed those tests.

For a similar theory in science perhaps you should do some research on neutrinos. These are weakly interacting particles that were used to explain missing energy in supernovae explosions. It has a lot of parallels with our current discussion on dark matter.


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 Message 25 by tesla, posted 06-08-2011 5:55 PM tesla has responded

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Taq
Member
Posts: 8445
Joined: 03-06-2009
Member Rating: 7.4


Message 28 of 113 (619141)
06-08-2011 6:03 PM
Reply to: Message 26 by tesla
06-08-2011 5:58 PM


Re: Not so fast....
And so far they have failed to do that.

Quite the opposite. They have tested their hypotheses and they have passed testing. The bullet cluster collision above is a perfect example.

The data has to be interpreted. It doesn’t mean initial interpretations are correct.

Can you please show why the interpretations are wrong?


This message is a reply to:
 Message 26 by tesla, posted 06-08-2011 5:58 PM tesla has acknowledged this reply

  
tesla
Member (Idle past 285 days)
Posts: 1199
Joined: 12-22-2007


Message 29 of 113 (619142)
06-08-2011 6:16 PM
Reply to: Message 27 by Taq
06-08-2011 6:01 PM


Re: Not so fast....
Every single observation we make anywhere is of old light. You seem to be throwing up arbitrary distances so that you can ignore the evidence.

Initial post. That site [The initial analyses] is from: is dedicated to new science. I'm pointing out there is not any evidence.

Scientists aren't guessing. They are creating hypotheses and testing those hypotheses

LMAO an 'educated' guess is still a guess !


keep your mind from this way of enquiry, for never will you show that not-being is
~parmenides

This message is a reply to:
 Message 27 by Taq, posted 06-08-2011 6:01 PM Taq has responded

Replies to this message:
 Message 30 by PaulK, posted 06-09-2011 1:51 AM tesla has responded
 Message 47 by Taq, posted 06-09-2011 3:28 PM tesla has responded

  
PaulK
Member
Posts: 16629
Joined: 01-10-2003
Member Rating: 3.0


(1)
Message 30 of 113 (619188)
06-09-2011 1:51 AM
Reply to: Message 29 by tesla
06-08-2011 6:16 PM


Re: Not so fast....
quote:

Initial post. That site [The initial analyses] is from: is dedicated to new science. I'm pointing out there is not any evidence.

That doesn't answer the point, and it isn't true. Aside from the fact that the story referred to in the OP only dealt with one form of dark matter and didn't touch on the evidence for dark matter in general there have been positive results from other experiments.

So lets be honest, shall we. You over-interpreted a story that was already out of date. And that's it.


This message is a reply to:
 Message 29 by tesla, posted 06-08-2011 6:16 PM tesla has responded

Replies to this message:
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