Dark Matter mapped
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thanks Andy
Andy Brummer wrote:
Heisenberg uncertainty principle
Im not sure I was referring to 'uncertainty' or maybe something to do with 'observability' (which between yours and Jeffry's replies will get me to do some more reading, which cant hurt :-) ) And maybe it was a different Heisenberg or the context I was given on one of his principles was just plain wrong thanks anyway to you both, its been an interesting read
Garth J Lancaster wrote:
Im not sure I was referring to 'uncertainty' or maybe something to do with 'observability' (which between yours and Jeffry's replies will get me to do some more reading, which cant hurt :) )
The uncertainty principle is often confused with the not-quite-so-bizarre "observer effect". The observer effect essentially says that the only way we can observe a thing is to smash some other thing into it and see what happens, which will necessarily change the behavior of the observed item. The uncertainty principle is more forceful - it says that even if we could measure the state of some system infinitely precisely, and in the process modify exactly nothing about the system's state, our calculations regarding the state of the system would still be off by at least a small unknowable factor. The weirdness comes from the math involved in the system, not from some hypothetical inaccuracy in measurement or a "bump" to the measured system. Wikipedia has a pretty good entry on the uncertainty principle. Lots of layman literature about it tends to mix it up with the observer effect, though... BTW: I'm no physicist, nor do I play one. If my statements above are incorrect or improperly skewed in one direction or another, I'd appreciate a slap from a real physicist :)
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Has anyone ever proposed what dark matter actually is? I mean if we got a box of it what would be in the box? I also assume it would be in our region of space, say within our solar system even?
regards, Paul Watson Ireland & South Africa
Shog9 wrote:
I don't see it happening, at least not until it becomes pointless.
No, you can't touch it and it can't touch you. As far as we know it only interacts with regular matter through the gravitational force which is the weakest force in existence. It is all over including our neck of the woods and there are experiments underway to try and detect any possible interaction with regular matter.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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I was just as skeptical of it as you a year or so ago so I got some basic textbooks on cosmology and dark matter. There are a lot of observations which rule out a simple explanation like the one you gave. Most galaxies have a uniform distribution of dark matter which produces the rotational pattern described. However some galaxies have a different distribution of dark matter which can be measured. Also the distribution in general depends on the type of galaxy. The distribution for our galaxy has been measured as well and it is non-uniform. There is a lot of evidence for some substance that pervades space called dark matter, true nobody knows what it is just yet, but there is nothing wrong with trying to figure out what and where it is. It looks like there is some new information in this study with dark matter showing up without matter. I agree that science reporting for the general public is pretty lame, since the press only cares about stories that bring readers, and very few reporters understand what they are reporting on. I think it's worse in health reporting though.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
The point I'm trying to make here is simply that theories should not be presented as facts. They should be presented as theories. For example:
Andy Brummer wrote:
Most galaxies have a uniform distribution of dark matter which produces the rotational pattern described.
You don't know that, and nobody else does either; the existence of dark matter, however likely or helpful in balancing the equations, has not been proven. The above statement, therefore, should be worded something like: "The rotational pattern of most galaxies could be explained by recourse to a uniform distribution of as-yet-undetected dark matter. The actual explanation, of course, may turn out to be something quite different. We simply don't know at this point." When theories are treated as facts, scientific enquiry is stifled, not encouraged.
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ed welch wrote:
It's not pseudo science, just because it hasn't been proven yet.
That's so funny. Do you use that same reasoning when talking about god or angels? And yet religion is scoffed at because it falls in to the realm of dark matter--completely unprovable, at least for now. Marc
People are just notoriously impossible. --DavidCrow
There's NO excuse for not commenting your code. -- John Simmons / outlaw programmer
People who say that they will refactor their code later to make it "good" don't understand refactoring, nor the art and craft of programming. -- Josh SmithSo in your book partially discovered is the same as unanswerable in principle?
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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It's incredible what astronomers can do nowadays. http://news.bbc.co.uk/1/hi/sci/tech/6235751.stm[^].
the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer
Deja View - the feeling that you've seen this post before.Wow, that's really cool :-D
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So in your book partially discovered is the same as unanswerable in principle?
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
Andy Brummer wrote:
So in your book partially discovered is the same as unanswerable in principle?
No--the point was, the statement "it's not psuedoscience just because it hasn't been proven" has been used in the reverse: "it's pseudoscience because it hasn't been proven" when dealing with the concepts such as god. So I found it quite humorous that what is deemed to be psuedoscience is apparently determined by one's subjective opinion of the subject matter. Theories of god is psuedoscience, theories of dark matter is not, regardless of the fact that neither are proven or, with current technologies, provable. Marc
People are just notoriously impossible. --DavidCrow
There's NO excuse for not commenting your code. -- John Simmons / outlaw programmer
People who say that they will refactor their code later to make it "good" don't understand refactoring, nor the art and craft of programming. -- Josh Smith -
Jeffry J. Brickley wrote:
We have mapped dark matter by detecting its gravitational influence.
The correct version of this statement is, "We have mapped an apparent gravitational influence. We do not know the cause. It may be dark matter, as we currently understand the term, or it may be something altogether different. In fact, it may not be a gravitational influence at all; it may be something else that appears to be a gravitational influence but is actually quite different. We simply don't know."
The Grand Negus wrote:
The correct version of this statement is, "We have mapped an apparent gravitational influence. We do not know the cause.
which is what dark matter is. Dark matter isn't a mystical object, it means exactly what its name implies, it is matter we cannot see that exerts gravitational influence over bodies we can see. There are numerous theories as to what exactly "is" dark matter, which is a completely separate set of theories from superstring, antimatter, quantum matter, to simple traditional 3D matter that our instruments are not strong enough to see.
The Grand Negus wrote:
it may be something else that appears to be a gravitational influence but is actually quite different.
You are correct, it could be giant man-made lenses to bend light. Ben Franklin left the earth to populate the universe with giant bifocals. However, the most likely cause, is gravity. You believe in galactic bifocals if you choose.
_________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
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The Grand Negus wrote:
The correct version of this statement is, "We have mapped an apparent gravitational influence. We do not know the cause.
which is what dark matter is. Dark matter isn't a mystical object, it means exactly what its name implies, it is matter we cannot see that exerts gravitational influence over bodies we can see. There are numerous theories as to what exactly "is" dark matter, which is a completely separate set of theories from superstring, antimatter, quantum matter, to simple traditional 3D matter that our instruments are not strong enough to see.
The Grand Negus wrote:
it may be something else that appears to be a gravitational influence but is actually quite different.
You are correct, it could be giant man-made lenses to bend light. Ben Franklin left the earth to populate the universe with giant bifocals. However, the most likely cause, is gravity. You believe in galactic bifocals if you choose.
_________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
Jeffry J. Brickley wrote:
[an apparent gravitational influence] which is what dark matter is.
Not exactly. Dark matter is postulated as something that causes an apparent gravitational influence; it is distinct from the influence which is (one of) its effects. The sun, for example, has a gravitational influence on the objects within it's sphere of influence, but the sun itself is not a gravitational influence of unknown origin, which is what these guys have mapped. I'll say it one last time: they have not mapped "dark matter" - they have mapped a gravitational influence of unknown origin, possibly caused by something like the dark matter they are busy imagining. See the difference? The way you say it presumes the existence of a mysterious, unobserved and unproven thing (dark matter); the way I say it leaves the field open for any plausible explanation (of the gravitational influences), awaiting more data before a decision is made.
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Andy Brummer wrote:
So in your book partially discovered is the same as unanswerable in principle?
No--the point was, the statement "it's not psuedoscience just because it hasn't been proven" has been used in the reverse: "it's pseudoscience because it hasn't been proven" when dealing with the concepts such as god. So I found it quite humorous that what is deemed to be psuedoscience is apparently determined by one's subjective opinion of the subject matter. Theories of god is psuedoscience, theories of dark matter is not, regardless of the fact that neither are proven or, with current technologies, provable. Marc
People are just notoriously impossible. --DavidCrow
There's NO excuse for not commenting your code. -- John Simmons / outlaw programmer
People who say that they will refactor their code later to make it "good" don't understand refactoring, nor the art and craft of programming. -- Josh SmithAh, I can see the humor in that. Whomever used the "it's pseudoscience because it hasn't been proven" phrase obviously doesn't understand what pseudoscience is though. That's a completely bogus statement.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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Pete O`Hanlon wrote:
It's incredible what astronomers can do nowadays.
It's not just a job! It's an adventure... well, kinda... :) That was my career direction before I discovered computers. :)
_________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
Jeffry J. Brickley wrote:
I discovered computers.
:-D
Nobody can give you wiser advice than yourself. - Cicero ப்ரம்மா
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The point I'm trying to make here is simply that theories should not be presented as facts. They should be presented as theories. For example:
Andy Brummer wrote:
Most galaxies have a uniform distribution of dark matter which produces the rotational pattern described.
You don't know that, and nobody else does either; the existence of dark matter, however likely or helpful in balancing the equations, has not been proven. The above statement, therefore, should be worded something like: "The rotational pattern of most galaxies could be explained by recourse to a uniform distribution of as-yet-undetected dark matter. The actual explanation, of course, may turn out to be something quite different. We simply don't know at this point." When theories are treated as facts, scientific enquiry is stifled, not encouraged.
True, in science's short history there have been theories that were slow to be overturned because scientists were slow to accept change. However, I think what you are proposing is as effective in combating that as putting 15 warning labels on everyday objects is at combating human stupidity. It's essentially the same thing. You have to assume the reader has a basic level of intelligence and isn't going to to take every statement at face value. I would think that giving it a nebulous name like "dark matter" would have been enough for most people.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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It's incredible what astronomers can do nowadays. http://news.bbc.co.uk/1/hi/sci/tech/6235751.stm[^].
the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer
Deja View - the feeling that you've seen this post before. -
Garth J Lancaster wrote:
Im not sure I was referring to 'uncertainty' or maybe something to do with 'observability' (which between yours and Jeffry's replies will get me to do some more reading, which cant hurt :) )
The uncertainty principle is often confused with the not-quite-so-bizarre "observer effect". The observer effect essentially says that the only way we can observe a thing is to smash some other thing into it and see what happens, which will necessarily change the behavior of the observed item. The uncertainty principle is more forceful - it says that even if we could measure the state of some system infinitely precisely, and in the process modify exactly nothing about the system's state, our calculations regarding the state of the system would still be off by at least a small unknowable factor. The weirdness comes from the math involved in the system, not from some hypothetical inaccuracy in measurement or a "bump" to the measured system. Wikipedia has a pretty good entry on the uncertainty principle. Lots of layman literature about it tends to mix it up with the observer effect, though... BTW: I'm no physicist, nor do I play one. If my statements above are incorrect or improperly skewed in one direction or another, I'd appreciate a slap from a real physicist :)
Russell Morris wrote:
The observer effect essentially says that the only way we can observe a thing is to smash some other thing into it and see what happens, which will necessarily change the behavior of the observed item.
That's the best interpretation of it I've seen. However the early interpretations of it were I know someone is watching me so I have to behave according to a completely different set of rules. The best description I've seen of modern theories about it state that if the state gets entangled with enough additional random states it has the same effect as the traditional observer rules, but I haven't been able to follow that math on that one. You are right about the uncertainty principle.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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I never saw you type this post! (And nobody saw me replying to it) :-D
-- For External Use Only
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True, in science's short history there have been theories that were slow to be overturned because scientists were slow to accept change. However, I think what you are proposing is as effective in combating that as putting 15 warning labels on everyday objects is at combating human stupidity. It's essentially the same thing. You have to assume the reader has a basic level of intelligence and isn't going to to take every statement at face value. I would think that giving it a nebulous name like "dark matter" would have been enough for most people.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
Andy Brummer wrote:
I would think that giving it a nebulous name like "dark matter" would have been enough for most people.
I don't know - anyone who can take "strange quarks" and "charm quarks" seriously will probably not have any inhibitions about "dark matter" :) . Until they get sued by the DarkBasic people [^]!
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Has anyone ever proposed what dark matter actually is? I mean if we got a box of it what would be in the box? I also assume it would be in our region of space, say within our solar system even?
regards, Paul Watson Ireland & South Africa
Shog9 wrote:
I don't see it happening, at least not until it becomes pointless.
Paul Watson wrote:
Has anyone ever proposed what dark matter actually is? I mean if we got a box of it what would be in the box?
Think of it as a an object, lets call it System.DM, and it has full permissions with System.Object plus some other System.Namespaces we are not even aware of yet. (that's the best I can type it as I am just about to retire for the night)
Later, JoeSox "The best stories don't come from 'good vs. bad' but from 'good vs. good.'" – Leo Tolstoy CPMCv1.0 ↔ humanaiproject.org ↔ Last.fm
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Jeffry J. Brickley wrote:
[an apparent gravitational influence] which is what dark matter is.
Not exactly. Dark matter is postulated as something that causes an apparent gravitational influence; it is distinct from the influence which is (one of) its effects. The sun, for example, has a gravitational influence on the objects within it's sphere of influence, but the sun itself is not a gravitational influence of unknown origin, which is what these guys have mapped. I'll say it one last time: they have not mapped "dark matter" - they have mapped a gravitational influence of unknown origin, possibly caused by something like the dark matter they are busy imagining. See the difference? The way you say it presumes the existence of a mysterious, unobserved and unproven thing (dark matter); the way I say it leaves the field open for any plausible explanation (of the gravitational influences), awaiting more data before a decision is made.
The Grand Negus wrote:
they have mapped a gravitational influence of unknown origin, possibly caused by something like the dark matter they are busy imagining.
"The composition of dark matter is unknown, but may include new elementary particles such as WIMPs, axions, and ordinary and heavy neutrinos, as well as astronomical bodies such as dwarf stars, planets collectively called MACHOs, and clouds of nonluminous gas. Current evidence favors models in which the primary component of dark matter is new elementary particles, collectively called non-baryonic dark matter." which basically says, dark matter is unknown. See??? You are arguing against "dark matter" as if it is some mystical confluence of known origin. It is simply an unknown object that we can only see through its gravitational influence. What we are measuring is the gravitational influence. You can say "apparent" all you want, but there is very little "known" that behaves as gravity does, which means you have to jump off a cliff and head into some REALLY strange quantum effects to get "apparent" gravity without gravity. Light doesn't like to bend easily. The easiest explanation of such a large mass of "apparent" gravitational effect is that it is gravity. You might as well hop on the ocean and demand that we stop calling it water, because it only has the appearance of water, but might actually be liquid oxidized copper. :rolleyes:
_________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
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The Grand Negus wrote:
they have mapped a gravitational influence of unknown origin, possibly caused by something like the dark matter they are busy imagining.
"The composition of dark matter is unknown, but may include new elementary particles such as WIMPs, axions, and ordinary and heavy neutrinos, as well as astronomical bodies such as dwarf stars, planets collectively called MACHOs, and clouds of nonluminous gas. Current evidence favors models in which the primary component of dark matter is new elementary particles, collectively called non-baryonic dark matter." which basically says, dark matter is unknown. See??? You are arguing against "dark matter" as if it is some mystical confluence of known origin. It is simply an unknown object that we can only see through its gravitational influence. What we are measuring is the gravitational influence. You can say "apparent" all you want, but there is very little "known" that behaves as gravity does, which means you have to jump off a cliff and head into some REALLY strange quantum effects to get "apparent" gravity without gravity. Light doesn't like to bend easily. The easiest explanation of such a large mass of "apparent" gravitational effect is that it is gravity. You might as well hop on the ocean and demand that we stop calling it water, because it only has the appearance of water, but might actually be liquid oxidized copper. :rolleyes:
_________________________ Asu no koto o ieba, tenjo de nezumi ga warau. Talk about things of tomorrow and the mice in the ceiling laugh. (Japanese Proverb)
Let's see if we can agree to this: (1) The scientists in question have developed a map of where the Dark Matter should be if their theories and calculations are correct. (2) This is a good thing. At least now we know where we're most likely to find the stuff, which should be a great aid to future research. (3) The common title of this thread and the article it references, "Dark Matter Mapped", is inaccurate because nobody - including the scientists in question - has located any actual Dark Matter. Actual Dark Matter hasn't been detected yet - postulated, yes, but not actually detected. All of our instruments indicate that there's nothing there, though the behavior of nearby objects indicate that there might be. How's that?
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No Marc, religion does not fall into the same category as dark matter. Theism, the basis of religion, falls under its own weight - it's not even logically self consistent! Furthermore, if anyone comes up with a better and more accurate way of describing the world as we know with ordinary matter, then scientists will drop the dark matter theories. I wish one could say the same about theologians...
-- LOADING...
Joergen Sigvardsson wrote:
... then scientists will drop the dark matter theories.
I seriously doubt about this. Did you know the ammount of money spended on this issues? Here are lot of money from national budget... and the scientists are almost condemned to die sustaining theire theories! :) The same situation is with evolution theory. Many scientists knows it is faulty, but, did someone change scholars textbooks? No.
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It's incredible what astronomers can do nowadays. http://news.bbc.co.uk/1/hi/sci/tech/6235751.stm[^].
the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer
Deja View - the feeling that you've seen this post before.