Dark Matter mapped
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Chris Losinger wrote:
i don't believe it. it's just a theory. nobody saw it happen.
That doesn't sound like the kind of attitude that helps advance technology and science. X|
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Garth J Lancaster wrote:
are there still things that we cant see because we dont have the correct technology/viewpoint
Yes - the 'ether' for one. And the gluons that hold everything together are invisible, too.
"...a photo album is like Life, but flat and stuck to pages." - Shog9
Roger Wright wrote:
Yes - the 'ether' for one
;P
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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Garth J Lancaster wrote:
are there still things that we cant see because we dont have the correct technology/viewpoint
Yes - the 'ether' for one. And the gluons that hold everything together are invisible, too.
"...a photo album is like Life, but flat and stuck to pages." - Shog9
I thought the idea of "ether" has long since been dismissed by virtually all physicists (except a few, who are still claiming that the earth is flat). :)
-- Nominated For Three Glemmys
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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 SmithNo 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...
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i don't believe it. it's just a theory. nobody saw it happen.
image processing toolkits | batch image processing | blogging
I never saw you type this post! (And nobody saw me replying to it) :-D
-- For External Use Only
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Nice reply, thanks ..
Jeffry J. Brickley wrote:
Also things change as we are watching them
wasnt that a Heisenberg principle - very roughly for us laymen, the more you observe something the more you are likely to interfere with whats happening ?... Ive suggested the same thing in monitoring real-time message flows at 'my shop' 'g'
Garth J Lancaster wrote:
wasnt that a Heisenberg principle
The Heisenberg uncertainty principle has to do with specially related properties of a quantum particle. You can measure the position in the x direction and in the y direction as accurately as you want at the same time. However, there is a fundamental limit to the accuracy you can measure the position and the velocity of the particle at the same time, because position in different directions are unrelated, but there is a fundamental relationship between a particles position and it's movement in that direction. It is a simple relationship in the mathematics of quantum mechanics, but there is no analogous object in human experience.
Garth J Lancaster wrote:
the more you observe something the more you are likely to interfere with whats happening
That sounds like a common statement about quantum measurement which has to do with another strange mathematical operation in quantum mechanics. In the Copenhagen interpretation of quantum mechanics, each particle has two states, observed and unobserved. Depending on it's state it will actually exhibit completely different behavior. For example an observed electron will only exist in one point in space, however unobserved it can be in multiple places at once. It's the weirdest damn thing in the world.
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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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...
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Garth J Lancaster wrote:
wasnt that a Heisenberg principle
The Heisenberg uncertainty principle has to do with specially related properties of a quantum particle. You can measure the position in the x direction and in the y direction as accurately as you want at the same time. However, there is a fundamental limit to the accuracy you can measure the position and the velocity of the particle at the same time, because position in different directions are unrelated, but there is a fundamental relationship between a particles position and it's movement in that direction. It is a simple relationship in the mathematics of quantum mechanics, but there is no analogous object in human experience.
Garth J Lancaster wrote:
the more you observe something the more you are likely to interfere with whats happening
That sounds like a common statement about quantum measurement which has to do with another strange mathematical operation in quantum mechanics. In the Copenhagen interpretation of quantum mechanics, each particle has two states, observed and unobserved. Depending on it's state it will actually exhibit completely different behavior. For example an observed electron will only exist in one point in space, however unobserved it can be in multiple places at once. It's the weirdest damn thing in the world.
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
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
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The Grand Negus wrote:
It's pseudo science when one "maps" what cannot be detected.
you misuse the phrasing. We have mapped dark matter by detecting its gravitational influence. Thus it is detected. It is simply unseen. Just because it does not emit energy does not mean it is not measurable. This series of measurements was to see if there was gravitational influence, thus it was looking and measuring and mapping gravitational affects on surrounding energy emitted from other visible objects. This showed that there was extra measurable/detectable/quantifiable gravitational influence in the area, we simply cannot "see" it because it emits no energy in a currently visible spectrum to our instruments. Therefore this is not "imagined" but measured through gravitational influence. Unless you are declaring that gravity does not exist? or cannot be measured?
_________________________ 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:
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."
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Joergen Sigvardsson wrote:
Theism, the basis of religion, falls under its own weight - it's not even logically self consistent!
Care to elaborate?
C# / DHTML / VG.net / MyXaml expert currently looking for work![^]
Right now, no. It's 2.37 am, and I have to get to work tomorrow morning. Theology tries to define the knowable (that which can be observed) by means of the unknowable (that which cannot be observed, or even defined: i.e. gods). From there on you can expand a bit further.. I suggest reading anything by George H. Smith for a fully fleshed out explanation.
-- This Episode Has Been Modified To Fit Your Primitive Screen
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Assuming, of course, that there is such a thing as "dark matter". See here[^] for an alternative opinion. The existence of dark matter is an unproven theory - prehaps right, perhaps wrong - but certainly unproven. There is no known test for the detection of dark matter; it's composition is unknown; it is a purely theoretical construct. Which is why no one should speak of "mapping it"; such pseudo-scientific statements are simply misleading.
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
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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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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