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> There is no evidence that dark matter even exists other than the fact that our universe is not expanding at the rate we think it should ... You're thinking o

by lutusp 10y ago

> There is no evidence that dark matter even exists other than the fact that our universe is not expanding at the rate we think it should ... You're thinking of dark energy, the net effect of which is to change the overall expansion profile of the universe as a whole. Dark Matter was first proposed when galactic rotation profiles failed to meet theoretical expectations -- matter far from the center of each galaxy had a higher velocity than it would if visible matter had been the only factor. > I think it's far more likely that our theory is incomplete rather than some whole new class of invisible matter/energy being conjured into existence Occam's razor (the simplest explanation tends to be the right one) suggests that a new unobserved particle is more likely than abandonment of F = GMmr^-2 . This doesn't mean the equation must be correct, it's a question of reaching for the low-hanging fruit. > So many non-scientists think dark matter is proven. It isn't. It's nothing but pure conjecture. First, nothing is ever proven true in science, only false. Second, dark matter is more than pure conjecture, since there is observational evidence. A pure conjecture would be an idea about reality having no observational support at all (unicorns, Bigfoot). Dark matter is a hypothesis crafted to explain observations, but so far there's no persuasive theory to explain it, and no observations of candidate particles either.

ClayFerguson 10y ago
I should have been clear that I'm not making a distinction between energy and matter. I'm referring to the postulated "dark" forms of both. Both of them are pure speculation, and is nothing but the equivalent of taking whatever observable "error" there is in our formulas and labeling it "dark". The only reason there's two kinds of "dark" is because both the space aspect (matter) of our math is wrong AND the time aspect (energy) is wrong. GR and SR are correct but incomplete, for representing spacetime. Just like Newtonian rules are correct but incomplete. And as for your last sentence, trust me I understand the scientific method, and how proof, evidence, and fact interrelate with knowledge. Nice philosophical observations, but having nothing to do with this discussion.
- digler999 10y ago
  the same thing could have been said about the discovery of Neptune [1]: "there's no evidence a planet is there, it's pure speculation. The changes in Uranus' orbit must be the result of mathematical error and not another planet." [1] https://en.wikipedia.org/wiki/Neptune https://en.wikipedia.org/wiki/Neptune
  - ClayFerguson 10y ago
    If man had discovered Gravitational Lensing BEFORE Einstein had formulated General Relativity we would have given some name to the effect, and perhaps even considered it a characteristic relationship between stars and light. The relationship happens to be an INDIRECT one. Star mass bends space, and the light merely "appears" to bend, when it traverses that space. It doesn't actually bend. What I'm saying about Dark energy/matter, is that there is also an INDIRECT relationship there. It's not just a special invisible mass and invisible energy. It's a fundamental misunderstanding about what spacetime is. I think the "dark" quantities are every bit as much an illusion as the "light bending" illusion created by stars.
    - lutusp 10y ago
      > Star mass bends space, and the light merely "appears" to bend, when it traverses that space. It doesn't actually bend. On the contrary, it actually bends. Spacetime curvature is a real, not an apparent, effect. "Spacetime tells matter how to move; matter tells spacetime how to curve." -- John Wheeler More on this topic: https://en.wikipedia.org/wiki/Einstein_ring https://en.wikipedia.org/wiki/Einstein_ring
      - ClayFerguson 10y ago
        The light is traveling in a straight line ALWAYS, but merely appears (to us) to bend, because the space it's traveling thru (in a straight line) is itself bent. The space itself is bent. The light goes straight. That's the distinction i was attempting to point out, when I said if mankind had visually noticed star-induced 'lensing' (before Einstein explaining what to expect) we would have ASSUMED the light itself was bending, and that space was 'flat' (unbent). Thinking space is flat and light is bent (the opposite of what is true), would have been the same kind of blunder we are making today believing that Dark matter/energy is actually real.
- lutusp 10y ago
  > The only reason there's two kinds of "dark" is because both the space aspect (matter) of our math is wrong AND the time aspect (energy) is wrong. You're pairing space and matter, then time and energy, and comparing them as though these entities are naturally paired in current theory. They aren't. Space and time are elements of spacetime, matter and energy are interchangeable by way of a rather well-known equation, but these things don't arrange themselves as you're trying to do. > And as for your last sentence, trust me I understand the scientific method, and how proof, evidence, and fact interrelate with knowledge. So you didn't say, "So many non-scientists think dark matter is proven. It isn't. It's nothing but pure conjecture." Nothing is ever proven in science (falsified, yes, proven, no). And dark matter and dark energy are both more than "pure conjecture," a domain reserved to notions lacking observational evidence.
- solipsism 10y ago
  I should have been clear that I'm not making a distinction between energy and matter. Come on. Is it so hard to say "Oops I mixed them up"?
  - ClayFerguson 10y ago
    I also use the words "space" and "time" independently as if they were separate things, when I know full well every last detail about SR/GR (being an engineer myself). So yes, only in the context of discussing "dark stuff" I will lazily interchange matter and energy. Only on HackerNews do I ever encounter the type of ass-holes who will parse sentences intentionally wrong as to yield the incorrect conclusion. You are one such person.
    - lutusp 10y ago
      > Only on HackerNews do I ever encounter the type of ass-holes who will parse sentences intentionally wrong as to yield the incorrect conclusion. You are one such person. Troll alert. Space and time are elements of spacetime, they are an integrated whole, a fact first pointed out by Einstein's math teacher Minkowski. When Einstein first read what Minkowski had written, he said, “Since the mathematicians have invaded the theory of relativity, I do not understand it myself anymore.” Only later, after learning tensor calculus and beginning work on GR, did Einstein understand what Minkowski was going on about. But in those days people were interested only in getting it right, not posturing as right even when they're wrong.
      - ClayFerguson 10y ago
        Nice dissertation on 2+2=4. I've known relativity for 30years. The point i was making (as i'm sure you genuinely DO actually know, despite pretending once again to need to correct me), is that even physics professors in the middle of physics lectures will say "space" or "time", depending on context. Learn the fact that English and all languages have syntactical nuances. Oh,and thanks for the warning that you are a Troll, but I don't mind. I'm biting the hook. Nothing thrills me more than debating physics. Thus the 30yrs.

by lutusp 10y ago

ClayFerguson 10y ago

I should have been clear that I'm not making a distinction between energy and matter. I'm referring to the postulated "dark" forms of both. Both of them are pure speculation, and is nothing but the equivalent of taking whatever observable "error" there is in our formulas and labeling it "dark". The only reason there's two kinds of "dark" is because both the space aspect (matter) of our math is wrong AND the time aspect (energy) is wrong. GR and SR are correct but incomplete, for representing spacetime. Just like Newtonian rules are correct but incomplete. And as for your last sentence, trust me I understand the scientific method, and how proof, evidence, and fact interrelate with knowledge. Nice philosophical observations, but having nothing to do with this discussion.

digler999 10y ago
the same thing could have been said about the discovery of Neptune [1]: "there's no evidence a planet is there, it's pure speculation. The changes in Uranus' orbit must be the result of mathematical error and not another planet." [1] https://en.wikipedia.org/wiki/Neptune https://en.wikipedia.org/wiki/Neptune
- ClayFerguson 10y ago
  If man had discovered Gravitational Lensing BEFORE Einstein had formulated General Relativity we would have given some name to the effect, and perhaps even considered it a characteristic relationship between stars and light. The relationship happens to be an INDIRECT one. Star mass bends space, and the light merely "appears" to bend, when it traverses that space. It doesn't actually bend. What I'm saying about Dark energy/matter, is that there is also an INDIRECT relationship there. It's not just a special invisible mass and invisible energy. It's a fundamental misunderstanding about what spacetime is. I think the "dark" quantities are every bit as much an illusion as the "light bending" illusion created by stars.
  - lutusp 10y ago
    > Star mass bends space, and the light merely "appears" to bend, when it traverses that space. It doesn't actually bend. On the contrary, it actually bends. Spacetime curvature is a real, not an apparent, effect. "Spacetime tells matter how to move; matter tells spacetime how to curve." -- John Wheeler More on this topic: https://en.wikipedia.org/wiki/Einstein_ring https://en.wikipedia.org/wiki/Einstein_ring
    - ClayFerguson 10y ago
      The light is traveling in a straight line ALWAYS, but merely appears (to us) to bend, because the space it's traveling thru (in a straight line) is itself bent. The space itself is bent. The light goes straight. That's the distinction i was attempting to point out, when I said if mankind had visually noticed star-induced 'lensing' (before Einstein explaining what to expect) we would have ASSUMED the light itself was bending, and that space was 'flat' (unbent). Thinking space is flat and light is bent (the opposite of what is true), would have been the same kind of blunder we are making today believing that Dark matter/energy is actually real.
lutusp 10y ago
> The only reason there's two kinds of "dark" is because both the space aspect (matter) of our math is wrong AND the time aspect (energy) is wrong. You're pairing space and matter, then time and energy, and comparing them as though these entities are naturally paired in current theory. They aren't. Space and time are elements of spacetime, matter and energy are interchangeable by way of a rather well-known equation, but these things don't arrange themselves as you're trying to do. > And as for your last sentence, trust me I understand the scientific method, and how proof, evidence, and fact interrelate with knowledge. So you didn't say, "So many non-scientists think dark matter is proven. It isn't. It's nothing but pure conjecture." Nothing is ever proven in science (falsified, yes, proven, no). And dark matter and dark energy are both more than "pure conjecture," a domain reserved to notions lacking observational evidence.
solipsism 10y ago
I should have been clear that I'm not making a distinction between energy and matter. Come on. Is it so hard to say "Oops I mixed them up"?
- ClayFerguson 10y ago
  I also use the words "space" and "time" independently as if they were separate things, when I know full well every last detail about SR/GR (being an engineer myself). So yes, only in the context of discussing "dark stuff" I will lazily interchange matter and energy. Only on HackerNews do I ever encounter the type of ass-holes who will parse sentences intentionally wrong as to yield the incorrect conclusion. You are one such person.
  - lutusp 10y ago
    > Only on HackerNews do I ever encounter the type of ass-holes who will parse sentences intentionally wrong as to yield the incorrect conclusion. You are one such person. Troll alert. Space and time are elements of spacetime, they are an integrated whole, a fact first pointed out by Einstein's math teacher Minkowski. When Einstein first read what Minkowski had written, he said, “Since the mathematicians have invaded the theory of relativity, I do not understand it myself anymore.” Only later, after learning tensor calculus and beginning work on GR, did Einstein understand what Minkowski was going on about. But in those days people were interested only in getting it right, not posturing as right even when they're wrong.
    - ClayFerguson 10y ago
      Nice dissertation on 2+2=4. I've known relativity for 30years. The point i was making (as i'm sure you genuinely DO actually know, despite pretending once again to need to correct me), is that even physics professors in the middle of physics lectures will say "space" or "time", depending on context. Learn the fact that English and all languages have syntactical nuances. Oh,and thanks for the warning that you are a Troll, but I don't mind. I'm biting the hook. Nothing thrills me more than debating physics. Thus the 30yrs.