Please turn on javascript in your browser to play chess.
Science Forum

Science Forum

  1. Standard member sasquatch672
    Don't Like It Leave
    11 Jan '09 17:35
    I've been thinking about this quite a bit. The acceleration of the universe's expansion can only be explained by the presence of a substance we can't see. I don't have the formal mathematical background and it certainly wouldn't fit in a readable post anyway. But that's what physicists say.

    String theory holds that what we call gravity is actually indentations in the fabric of space-time by celestial objects. I illustrated this point in Bosse De Nage's "Origins of Gravity" thread; I will reproduce it here. String theory holds that what we think of as empty space can be accurately modeled an infinite number of layers of infinitely thin sheets, stretched taut. if you take one of these sheets and place a bowling ball on it, the bowling ball will make an indentation. Another smaller celestial object will come along from time to time and fall into this groove; now you have a moon in orbit.

    My point is this. In my reading, I've never heard it proposed that the fabric of space-time is the long sought-after dark matter. Is it possible that space is not empty, and that what we think of as space is actually the dark matter matrix of the universe? Does someone smarter and more well-versed than I care to take up the conversation at this point?
  2. 11 Jan '09 20:00
    Originally posted by sasquatch672
    I've been thinking about this quite a bit. The acceleration of the universe's expansion can only be explained by the presence of a substance we can't see. I don't have the formal mathematical background and it certainly wouldn't fit in a readable post anyway. But that's what physicists say.

    String theory holds that what we call gravity is actual ...[text shortened]... ne smarter and more well-versed than I care to take up the conversation at this point?
    The model of inifinite number of layers of of sheets. Seems too complicated. These 'sheets' don't exist viewed as real sheets, it's only a model, nothing more.

    The beginning of astronomy, we thought that things we could see with telescopes was the things that existed, nothing more. By the birth of radio astronomy we learned that there are more than that. Dark gas clouds, as an example. But this was not enough to explain the behaviour of the galaxial rotation. There must be more than that.

    We also thought that the expansion rate of the Universe was too fast. With the current rate the Universe would expand forever, and that the Universe in that case was a one time event. Not satisfactory.

    So there are things with gravitation more than we know about. What is this?

    Now we think that there is not only masses of ordinary matter, but also particles that don't interact with photons, i.e. cannot be seen, cannot be detected other than with its gravitation. Exotic particles? Free quarks? Or perhaps fields of 'dark energy'?

    This dark energy doesn't only possess mass, it also repells matter. The result is that the Universe is thought to, not only expanding, but also accelerating expanding. A force stronger than the Universes collected gravitation. Do we know what this is? No. Do we know anything about it? No. But it fits nicely in the explanations of what's in the vast voids between the cluster of galaxies, and the future of our universe. Seems that the Univers is a one time event after all.

    Do I believe in dark energy? No.
  3. Standard member sasquatch672
    Don't Like It Leave
    12 Jan '09 01:57
    Originally posted by FabianFnas
    The model of inifinite number of layers of of sheets. Seems too complicated. These 'sheets' don't exist viewed as real sheets, it's only a model, nothing more.

    The beginning of astronomy, we thought that things we could see with telescopes was the things that existed, nothing more. By the birth of radio astronomy we learned that there are more than tha ...[text shortened]... ems that the Univers is a one time event after all.

    Do I believe in dark energy? No.
    Dark matter is there, and exists. It doesn't care whether or not you believe in it.
  4. 12 Jan '09 05:40
    Originally posted by sasquatch672
    Dark matter is there, and exists. It doesn't care whether or not you believe in it.
    Dark matter, yes.
    Dark energy, no.
    And of course it's there, even if I don't believe it.
  5. Standard member sasquatch672
    Don't Like It Leave
    12 Jan '09 13:24
    Originally posted by FabianFnas
    Dark matter, yes.
    Dark energy, no.
    And of course it's there, even if I don't believe it.
    E=MC^2
  6. 12 Jan '09 14:20
    Originally posted by sasquatch672
    E=MC^2
    Do you imply that mass and energy is equivalent? Even that dark mass and dark energy is equivalent? Do we really know that much about dark mass and dark energy to make this asumption? I don't know...

    Mass of the ordinary matter has a gravitational attraction. One thing I want to know is if dark matter has a gravitational repellation, and if this has to do with the accellerating expanition of the Universe? Or is it a fifth force of nature, besides the four well known?
  7. Standard member Palynka
    Upward Spiral
    12 Jan '09 14:31
    Originally posted by FabianFnas
    Dark energy, no.
    What are the alternatives that can possibly explain the acceleration of the universe's expansion?
  8. 12 Jan '09 14:34
    Originally posted by Palynka
    What are the alternatives that can possibly explain the acceleration of the universe's expansion?
    I don't even know why dark matter or dark energy is responsible to the expansion.
    Why does dark matter or dark energy an repellant property, when normal matter hasn't...?
  9. 12 Jan '09 14:39
    Originally posted by sasquatch672
    E=MC^2
    The use of relativistic mass is obsolete, really.
  10. Standard member Palynka
    Upward Spiral
    12 Jan '09 14:43 / 1 edit
    Originally posted by FabianFnas
    I don't even know why dark matter or dark energy is responsible to the expansion.
    Why does dark matter or dark energy an repellant property, when normal matter hasn't...?
    I'm not saying skepticism is not a valid reason to not believe in dark energy, I was just asking if there were any alternative hypothesis.
  11. 12 Jan '09 15:13
    Originally posted by Palynka
    I'm not saying skepticism is not a valid reason to not believe in dark energy, I was just asking if there were any alternative hypothesis.
    Well, my strongest objection about a repellant dark energy/matter is that I don't find it a beautiful explanation. But I know that the Universe doesn't gives a rats a$$ about what I think about it.
    My alternative is hard to describe in ascii-text, so I wait until that solution is described in some web-page with a illustration.
  12. Standard member Thequ1ck
    Fast above
    12 Jan '09 16:34 / 1 edit
    I'm more inclined to believe that the high expansion rate of the universe is more
    likely to be due to strange Mathematics on scales such as the universe.
    I'd be backing some of the unorthodox longshots on this one and feel that using
    words such as 'energy' and 'matter' to describe situations of anomolous results
    is really a cop out.

    "For example, dark energy may arise from quantum information loss at the cosmic horizon"
    'entropy' - M. Paul Gough
    http://www.mdpi.org/entropy/papers/e10030150.pdf

    The idea put forward in this article is that the process of losing information such as
    stars travelling away from us faster than the speed of light (with respect to special
    relativity) has an effect on the net entropy of the universe. Much in the same was
    as resetting information on a RAM chip or the sentient abstracts of God in the book
    'God's debris'.
  13. Standard member sasquatch672
    Don't Like It Leave
    14 Jan '09 04:17
    Originally posted by FabianFnas
    Do you imply that mass and energy is equivalent? Even that dark mass and dark energy is equivalent? Do we really know that much about dark mass and dark energy to make this asumption? I don't know...

    Mass of the ordinary matter has a gravitational attraction. One thing I want to know is if dark matter has a gravitational repellation, and if this has to ...[text shortened]... ting expanition of the Universe? Or is it a fifth force of nature, besides the four well known?
    Come on lad, I've read your posts, you're more educated than that. I don't imply that and I don't need to; furthermore, if I stated that, I would be as humble an emissary of that concept as there has ever been. As to your second question - this is a theory, not a law, because it doesn't fit the definition of a scientific law, but it's a pretty damn well observed theory - well hell - Einstein stated it himself: the laws of physics apply uniformly to all nonaccelerating bodies in motion. That means everywhere, all the time, to everything. We haven't figured out how to "see" dark matter. But we can make reasonable assumptions about it - among them, that the laws of physics apply to it.
  14. Standard member sasquatch672
    Don't Like It Leave
    14 Jan '09 04:18
    Originally posted by Thequ1ck
    I'm more inclined to believe that the high expansion rate of the universe is more
    likely to be due to strange Mathematics on scales such as the universe.
    I'd be backing some of the unorthodox longshots on this one and feel that using
    words such as 'energy' and 'matter' to describe situations of anomolous results
    is really a cop out.

    "For example, dar ...[text shortened]... rmation on a RAM chip or the sentient abstracts of God in the book
    'God's debris'.
    Very superficial, not well thought-out - come on, you're capable of more than this as well.
  15. Standard member sasquatch672
    Don't Like It Leave
    14 Jan '09 04:19
    Originally posted by KazetNagorra
    The use of relativistic mass is obsolete, really.
    Stop being more intelligent than the rest of us, come down out of the clouds, and explain yourself.