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Author Topic:   Dark matter a dying theory?
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 13 of 113 (619089)
06-08-2011 8:25 AM
Reply to: Message 3 by slevesque
06-08-2011 12:00 AM


slevesque writes:
The question becomes: when do you stop looking for vulcan and start thinking of alternative explanations?
Yeah, you're right, even though a Nobel awaits the team that uncovers the nature of what we currently call dark matter, scientists march in lock step to their preconceptions and refuse to think outside the box. Over the past decade the articles I've read have described scientists who are confining themselves to only the most pedestrian of possibilities.
  • Yet undiscovered forms of matter? How boring is that!
  • Mini-black holes created during the big bang? Yawn.
  • Modified laws of physics? Snore.
  • Effects of extra dimensions? Soporific (look it up).
--Percy

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 Message 3 by slevesque, posted 06-08-2011 12:00 AM slevesque has not replied

Replies to this message:
 Message 39 by slevesque, posted 06-09-2011 2:37 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


(1)
Message 34 of 113 (619230)
06-09-2011 9:27 AM
Reply to: Message 31 by tesla
06-09-2011 2:49 AM


Re: Not so fast....
Hi Tesla,
I think you're conflating two different things.
There is something we cannot see exerting a gravitational influence on galaxies. We don't know what is exerting this force, but we've given it a name: dark matter. We have very strong observational evidence of this phenomena.
What we don't have any good evidence for is the nature of dark matter. We don't know what it is. No one is claiming we know what it is. One cannot make claims based upon insufficient evidence.
There are a number of hypotheses about the nature of dark matter. Maybe one of them is right, maybe not. We don't know yet.
--Percy

This message is a reply to:
 Message 31 by tesla, posted 06-09-2011 2:49 AM tesla has replied

Replies to this message:
 Message 35 by tesla, posted 06-09-2011 11:17 AM Percy has replied
 Message 43 by slevesque, posted 06-09-2011 3:04 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


(1)
Message 36 of 113 (619329)
06-09-2011 1:53 PM
Reply to: Message 35 by tesla
06-09-2011 11:17 AM


Re: Not so fast....
tesla writes:
There is something we cannot see exerting emotional and behavioral influence on mankind. We don't know why this force has such influence, but we have given it names like "God" or "Belief structure". We have very strong observational evidence of this phenomena.
The problem with this analogy is your labels. "Dark matter" is a relatively neutral label that doesn't imply any particular conclusion about the nature of dark matter. "God" on the other hand is pretty specific about the nature of this influence. "Belief structure" is an improvement but still far too specific. But I think few would have much problem with this analogy if you were to choose a truly neutral term, maybe "psychology" for example.
Stating this another way, people's behavior and feelings and responses to stimulus are very real, but calling the phenomenon responsible "God" or "Belief structure" is to imply a specific answer where we don't really have one. "Dark matter" as it is interpreted within the physics community implies no specific answer at this time.
Or coming at this from yet another angle, when we say "dark matter" is responsible for keeping rotating galaxies from flying apart we haven't narrowed down the answer. It could be a form of matter that only rarely interacts with normal matter, or it could be objects that do not give off enough light to be detected, or it could be that we don't quite have the laws of physics correct yet, or it could be the influence of extra dimensions, or it be something else I haven't included here since this isn't a complete list, or it could be something no one has thought of yet.
But when you say "God" is "exerting emotional and behavioral influences on mankind" you're implying a very specific answer, one you have no evidence for.
--Percy

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 Message 35 by tesla, posted 06-09-2011 11:17 AM tesla has replied

Replies to this message:
 Message 37 by tesla, posted 06-09-2011 2:13 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


(1)
Message 40 of 113 (619346)
06-09-2011 2:53 PM
Reply to: Message 37 by tesla
06-09-2011 2:13 PM


Re: Not so fast....
Okay, let me try another tack.
Let us grant for the sake of discussion that God is a proven and well identified phenomenon. In that case, "dark matter" fits into a different category because, unlike God, we have no idea what it is. "Dark matter" is merely a label for the unknown cause of the gravitational influence that prevents rotating galaxies from flying apart. The gravitational influence itself is well established, but the cause of that influence is not. We give the cause of this gravitational influence the name "dark matter."
--Percy

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 Message 37 by tesla, posted 06-09-2011 2:13 PM tesla has replied

Replies to this message:
 Message 45 by tesla, posted 06-09-2011 3:22 PM Percy has seen this message but not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 60 of 113 (619386)
06-09-2011 4:20 PM
Reply to: Message 53 by Taq
06-09-2011 3:41 PM


Re: Not so fast....
Taq writes:
What is wrong with the explanation that this gravitational influence is due to matter that does not absorb, emit, or reflect light as well as having very weak interactions with luminous matter? What do you find so objectionable? It fits the data perfectly.
What is leading Tesla astray, and I think you also, is that the term "dark matter" encompasses possibilities that are not matter, such as modified laws of physics or extra dimensions. When the term "dark matter" was originally proposed back in the 1980s and maybe before the only alternatives envisioned *were* actually matter, euphemistically called WIMPs (Weakly Interactive Massive Particles) and MACHOs (Massive Compact Halo Objects), but since that time a whole host of other possibilities have been proposed. The term "dark matter" no longer encompasses only possibilities that are matter.
--Percy

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 Message 53 by Taq, posted 06-09-2011 3:41 PM Taq has replied

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 Message 62 by Taq, posted 06-09-2011 4:35 PM Percy has seen this message but not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 63 of 113 (619395)
06-09-2011 4:36 PM
Reply to: Message 39 by slevesque
06-09-2011 2:37 PM


slevesque writes:
What I'm saying is that I see little basis for such a strong tendency to think unknown kinds of matter are responsible for what we see
This seems to be a common misconception. The term dark matter encompasses possibilities that are not matter. Look at my list - you quoted it, you should try reading it, too. These items were on the list:
  • Modified laws of physics?
  • Effects of extra dimensions?
Neither of those possibilities are matter. If you'd like a more complete (and accurate) list of non-matter possibilities then you should check with Cavediver.
--Percy
Edited by Percy, : Bad code.

This message is a reply to:
 Message 39 by slevesque, posted 06-09-2011 2:37 PM slevesque has replied

Replies to this message:
 Message 75 by slevesque, posted 06-09-2011 10:35 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 65 of 113 (619400)
06-09-2011 4:46 PM
Reply to: Message 43 by slevesque
06-09-2011 3:04 PM


Re: Not so fast....
slevesque writes:
What we do observe is a difference between the theoretical mass a galaxy contains, inferred from it's rotating speed, and the observed visible mass it actually contains.
This would be incorrect. As the acronym for one of the original alternatives for dark matter implies (MACHOs, Massive Compact Halo Objects), the dark matter was thought to exist in a halo outside the galaxy.
''Dark matter'' isn't the name being given to this phenomenon, it is the name of one of the explanation thought possible: that this indicates additional matter exists that has a gravitational influence. The terms dark matter therefore aren't as general as you say they are, and they certainly imply a certain amount of specificity contrary to what you say in your next message.
The original possibilities for dark matter *were* actually matter (MACHOs and WIMPs), but the list of possibilities has expanded to include non-matter possibilities. The original term persists.
The original criticism that science is not considering alternative explanations for dark matter beyond those that include matter is incorrect.
I understand that the term dark matter may seem misleading, but historically that is the name that the cause of the phenomenon was given, and so that is the name we happen to be stuck with. Take it up with Webster.
--Percy

This message is a reply to:
 Message 43 by slevesque, posted 06-09-2011 3:04 PM slevesque has not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 80 of 113 (619519)
06-10-2011 7:52 AM
Reply to: Message 74 by slevesque
06-09-2011 10:27 PM


Re: Not so fast....
slevesque writes:
But if, by putting a kettel of water on the stove, I hypothesise that it will boil eventually, then whether it turns out to be true or false the fact remains that it was an educated guess.
Your problem is with simple English terminology, not science. The term "educated guess" would never be used to describe the belief that a kettle on the stove will boil.
If they don't know whether there's water in the kettle or whether the burner is on, then that makes it a guess, not an "educated guess."
An example of an educated guess: Your wife has left the house for work but forgotten the report she completed last night. Her work is far away and in the wrong direction for you, but you know she was low on gas (petrol) and so make an educated guess that you might be able to catch her at the gas station, also making an educated guess of which gas station because you know she likes the latte at the Mobil station.
But if you access the GPS in her cell then her location is no longer an educated guess, nor is it a verified hypothesis. In science we would call it a theory, I suppose, but in real life we would call it a fact that she is precisely where her GPS says she is.
There is a marked tendency on the part of creationists to invent their own terminology. I guess it's much easier to be right if you can claim words mean anything convenient for your arguments, but there's really not much point to it.
--Percy

This message is a reply to:
 Message 74 by slevesque, posted 06-09-2011 10:27 PM slevesque has not replied

Replies to this message:
 Message 88 by slevesque, posted 06-14-2011 1:23 AM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 81 of 113 (619521)
06-10-2011 8:01 AM
Reply to: Message 75 by slevesque
06-09-2011 10:35 PM


slevesque writes:
I'm pretty sure the misconception is yours, modified laws of physics and effects of extra dimensions would not be described as dark matter, but rather as alternative explanations to dark matter.
Okay, if you like. What's the point of this quibble? The only term available for the phenomenon is "dark matter." There's no other. If they eventually find out that the explanation is not a form of matter but, say, modified gravity waves, then the problem that they'll say was solved is "dark matter."
I'm not sure why the quibbling over terminology. Tesla claimed that alternative ideas weren't being considered for dark matter. If you want to claim that dark matter can only refer to solutions that involve matter then of course you are right because by your definition the consideration of alternative ideas is ruled out, but the fact of the matter is that alternative ideas are most definitely receiving attention. They're even described in the Wikipedia article on dark matter that you referenced.
--Percy

This message is a reply to:
 Message 75 by slevesque, posted 06-09-2011 10:35 PM slevesque has replied

Replies to this message:
 Message 89 by slevesque, posted 06-14-2011 1:35 AM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 94 of 113 (620125)
06-14-2011 9:01 AM
Reply to: Message 88 by slevesque
06-14-2011 1:23 AM


Re: Not so fast....
slevesque writes:
But you'll have to point to me where an educated guess and a hypothesis are any different in a substantial way. As I see it, hypothesis is used when talking about aneducated guess in the field of science.
You want me to explain it again? Why? It was all there in simple English in my Message 80 that you replied to. You managed to quote almost the only part of the message that wasn't part of that explanation.
Anyway, one more time, but more briefly and forcefully, no English speaking person in their right mind would ever call a belief that a pot on the stove would boil as an educated guess or a hypothesis. That you used this example means you seriously misunderstand both terms, which are not synonyms anyway.
Capisce?
Why are you trying to denigrate "hypothesis" by defining it as an educated guess? Is it that you want to be able to say something like, "A hypothesis is just an educated guess, so when scientists are hypothesizing they're really just guessing."
It isn't like there isn't some degree of commonality, but they are not synonyms. Look them up. Why are you so intent on misexpressing yourself in English?
My advice is to figure out what you're trying to say in terms that you and your opponents both understand in the same way, then express yourself in those terms as clearly as possible. Quit playing word definition games.
--Percy

This message is a reply to:
 Message 88 by slevesque, posted 06-14-2011 1:23 AM slevesque has replied

Replies to this message:
 Message 97 by slevesque, posted 06-14-2011 2:02 PM Percy has replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 95 of 113 (620127)
06-14-2011 9:08 AM
Reply to: Message 89 by slevesque
06-14-2011 1:35 AM


slevesque writes:
No, I am right...
Well, we know you think so. Your message is quite a labyrinth of rationale - I think I'm going to leave it alone. If you've managed to persuade yourself, fine.
Tesla claimed no one was investigating alternatives to matter as the explanation for dark matter. Turns out that's wrong.
You can resume playing word games now.
--Percy

This message is a reply to:
 Message 89 by slevesque, posted 06-14-2011 1:35 AM slevesque has not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 99 of 113 (620198)
06-14-2011 6:43 PM
Reply to: Message 97 by slevesque
06-14-2011 2:02 PM


Re: Not so fast....
Hi Slevesque,
If it makes you feel better to say I'm wrong to use the term dark matter in the way I do then go right ahead, but it doesn't change the meaning of anything I said, and I think everyone, including you, understood what I said. Let me say it again in a way you'll be happier with, but it doesn't change anything:
The discussion in this thread revealed that scientists are exploring possibilities beyond dark matter to explain the anomalies in observed galactic rotation.
--Percy

This message is a reply to:
 Message 97 by slevesque, posted 06-14-2011 2:02 PM slevesque has not replied

  
Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


(1)
Message 100 of 113 (620291)
06-15-2011 8:28 AM
Reply to: Message 97 by slevesque
06-14-2011 2:02 PM


Re: Not so fast....
Hi Slevesque,
I did some more research and I have more time now, so I'll reply again but a bit more completely this time.
First, in the interest of precision, clarity and honesty I should state unequivocally that you are correct and I was wrong about the definition of dark matter. Dark matter refers only to hypotheses of galactic rotational anomalies that involve matter.
But second, this is important only if your interest is terminological precision. All the information I provided about dark matter hypotheses and alternative hypotheses was correct, plus lumping all the hypotheses under the dark matter label is convenient, is often done, and confuses no one.
About your "pot on the stove" example being a simple representative of a scientific experiment and a hypothesis, I think that's fine. But if you are actually interested in terminological precision then when talking about science I suggest you use the terminology of science. In other words, say "hypothesis" and not "educated guess," otherwise you'll make those on the science side nervous because it looks a lot like creationist arguments about how scientists are really only guessing and making assumptions.
--Percy

This message is a reply to:
 Message 97 by slevesque, posted 06-14-2011 2:02 PM slevesque has not replied

  
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