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The Paradoxes That Threaten To Tear Modern Cosmology Apart

KentuckyFC writes Revolutions in science often come from the study of seemingly unresolvable paradoxes. So an interesting exercise is to list the paradoxes associated with current ideas in science. One cosmologist has done just that by exploring the paradoxes associated with well-established ideas and observations about the structure and origin of the universe. Perhaps the most dramatic of these paradoxes comes from the idea that the universe must be expanding. What's curious about this expansion is that space, and the vacuum associated with it, must somehow be created in this process. And yet nobody knows how this can occur. What's more, there is an energy associated with any given volume of the universe. If that volume increases, the inescapable conclusion is that the energy must increase as well. So much for conservation of energy. And even the amount of energy associated with the vacuum is a puzzle with different calculations contradicting each other by 120 orders of magnitude. Clearly, anybody who can resolve these problems has a bright future in science but may also end up tearing modern cosmology apart.

131 of 231 comments (clear)

  1. "inescapable conclusion" by Anonymous Coward · · Score: 2, Insightful

    > What's more, there is an energy associated with any given volume of the universe. If that volume increases, the inescapable conclusion is that the energy must increase as well. So much for conservation of energy.

    ???
    Why cant the energy just be less dense?

    1. Re:"inescapable conclusion" by Anonymous Coward · · Score: 5, Informative

      The vacuum seems to have energy, so if space itself expands, the vacuum left has to either not have any energy whatsoever or drain the energy from nearby space. And since the energy of the vacuum seems to be constant, the conclusion is that the expansion is creating vacuum with its own energy

    2. Re:"inescapable conclusion" by Strangely+Familiar · · Score: 4, Insightful

      I think it is because vacuum energy is calculated on the basis of the field theory, which in turn depends on constants like the charge of the electron. I am pretty certain that calculations of the vacuum energy do not depend on the size of the universe. Puzzles like these are really important so that people can think of new questions to ask based on problems they didn't previously realize existed. These puzzles challenge our notions of space and time, which to me, are pretty tenuous notions.

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    3. Re:"inescapable conclusion" by Anonymous Coward · · Score: 1, Interesting

      Also, I saw the evidence for "modern" physics and I've never been convinced of it. As far as I can tell, the void is filled of all possible particles and matter are the "empty" bubbles breaking the symmetry, that would make possible the transversal waves in the void that killed the ether theory, explain why there is a limit to the speed of anything and would provide a medium of propagation for the forces without falling back to "magic" fields.

      It would also provide a framework to explain why there is energy in the vacuum and why the expansion of the universe leaves energy behind (some kind of horizon event taking antimatter and leaving "space" holes behind... that would also explain the matter\antimatter asymmetry in the universe).

      Yes, I know. the nobel prize will be shared amongst all ac's that ever posted here

    4. Re:"inescapable conclusion" by gmagill · · Score: 1

      Why cant the energy just be less dense?

      up to what point?

    5. Re: "inescapable conclusion" by rickb928 · · Score: 1

      Clearly to zero.

      Hence the article, and the questions.

      --
      deleting the extra space after periods so i can stay relevant, yeah.
    6. Re:"inescapable conclusion" by BarbaraHudson · · Score: 4, Funny

      void that killed the ether theory, explain why there is a limit to the speed of anything and would provide a medium of propagation for the forces without falling back to "magic" fields.

      Any sufficiently advanced universe is indistinguishable from magic :-)

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    7. Re:"inescapable conclusion" by fyngyrz · · Score: 1

      I am pretty certain that calculations of the vacuum energy do not depend on the size of the universe.

      I am pretty certain the idea's never been tested. And may not even be testable. So you might want to adjust your confidence level a bit. At least until we can go everywhere and measure everything. Breath-holding doesn't seem to be called for.

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      I've fallen off your lawn, and I can't get up.
    8. Re:"inescapable conclusion" by Baloroth · · Score: 4, Informative

      > What's more, there is an energy associated with any given volume of the universe. If that volume increases, the inescapable conclusion is that the energy must increase as well. So much for conservation of energy.

      ??? Why cant the energy just be less dense?

      The FLRW metric (which is what the equation that governs the cosmological expansion of spacetime) has a cosmological constant term in it, initially placed there by Einstein to maintain a steady state universe, but which we now know drives an accelerating expansion of the universe. This constant term is exactly that: a constant (negative) energy per volume of space. More space means more total energy.

      However, TFS and TFA (I've only scanned the referenced paper, but that looks much more reasonable) are absolutely wrong about why this is a problem. It is a problem, but only in the sense of figuring out where it comes from (i.e. what exact mechanism drives the creation of this energy). The fact that energy is not conserved violates no law of physics: in fact, general relativity doesn't conserve energy anyways, and the expansion of the universe certainly does not (even without the non-conservative nature of gravity).

      See, the conservation of energy is a result of Noether's theorem, which states that for any differentiable symmetry of the action of a physical system, there is a corresponding paired conservation law. For time symmetry, this is the conservation of energy. However, time on the scales of the universe is not symmetric. There was a beginning to the universe (which alone breaks the symmetry: you can't shift backwards in time more than ~13 billion years), and the universe as it is now looks nothing like it did 10 billion years ago. So we don't expect energy to be conserved in the universe as a whole (even if it is on local scales).

      --
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    9. Re:"inescapable conclusion" by Anonymous Coward · · Score: 5, Informative

      in fact, general relativity doesn't conserve energy anyways,

      GR does conserve energy, but in a very messy way with a lot of subtleties that means it gets skipped over in the grad level intro courses. Especially when dealing with an expanding metric, it is possible to formulate a contrived analogy to potential energy.

      There was a beginning to the universe (which alone breaks the symmetry: you can't shift backwards in time more than ~13 billion years), and the universe as it is now looks nothing like it did 10 billion years ago.

      The beginning of the universe does not need to conserve energy, but things as far as we can tell are conserved after that. The fact that things look different doesn't contradict the type of symmetry needed by Noether's theorem, just as Noether's theorem applies just fine in classical mechanics despite the second law of thermodynamics.

    10. Re:"inescapable conclusion" by Anonymous Coward · · Score: 1

      That is what any fundamental theory is about. At some level, if you keep asking why things are the way they are, the answer will be, "Because that is what it looks like when we observe things." Whether that is in the form of fields, strings, particles, etc., can't change that, unless the natural philosophers were right that the universe can be deduced from pure logic without observation.

    11. Re:"inescapable conclusion" by Strangely+Familiar · · Score: 1

      unless the natural philosophers were right that the universe can be deduced from pure logic without observation.

      Now that is an interesting notion. Unless you believe in the soul, or a "ghost in the machine" theory of consiousness, then pure logic, as a resident of the physical human brain, should obey the laws of physics just as any other physical thing obeys the laws of physics. In a sense, pure logic can be both an experiment and an observation.

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    12. Re:"inescapable conclusion" by Viol8 · · Score: 1

      "The beginning of the universe does not need to conserve energy, but things as far as we can tell are conserved after that."

      As fas as we can tell beig the important clause there. Besides which - the energy causing the expansion could be coming from outside our universe if one adhers to the multiverse theory , in which case all bets are off.

    13. Re:"inescapable conclusion" by robi5 · · Score: 1

      Nah, it's much simpler. The universe is floating in a sea of vacuum, which seeps through the pores of the universe, i.e. it's statistically unlikely but the energy balance is zero. You can immediately grasp the concept if you think of a squashed sponge ball, which as it expands, it soaks up air from its neighborhood. And of course if physicists are happy to buy into the idea that the Universe just sprang out of nothing, why not think that it sprang out like a sponge ball compressed (or nanoprinted) into a tiny space?

      **ducks**

    14. Re:"inescapable conclusion" by towermac · · Score: 1

      I've always felt like the big bang was an easy out to both explain red shift and allow for creation. Not that I have a problem with creation or the existence of God even; it just seems awfully convenient.

      $1 says we go back to a steady state universe in our lifetime.

    15. Re:"inescapable conclusion" by ultranova · · Score: 1

      The vacuum seems to have energy, so if space itself expands, the vacuum left has to either not have any energy whatsoever or drain the energy from nearby space.

      But if cosmological constant is greater thanzero, then our normal intuition of gravity is simply incorrect: what we perceive as gravitational potential is simply the crater at the top of a mountain of infinite height. No conservation law is being broken here, the universe simply contains a built-in wellspring of endless energy that's paying for the creation. Think of it as the ultimate renewable: very disperse but utterly inexhaustible.

      --

      Forget magic. Any technology distinguishable from divine power is insufficiently advanced.

    16. Re:"inescapable conclusion" by justthinkit · · Score: 1

      Your FLRW link does not resolve. Click the first result on this page to get there. "i with a hat" problem...

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    17. Re:"inescapable conclusion" by david_thornley · · Score: 2

      Pure logic gives us tautologies and nothing more. (They can be very complicated, interesting, and useful tautologies, of course.) Since tautologies hold no matter what the state of the Universe, they can't tell us anything about the state of the Universe.

      The idea of synthetic a priori knowledge comes, I think, from geometry and arithmetic. Way back when, these were recognized as pure logic, but they were also believed to be descriptions of reality. There was also metaphysics, which AFAICT was based largely on grammar: if you describe the world with nouns and adjectives, it's natural to think of substances with attributes. Eventually, we figured out that arithmetic and geometry aren't universally applicable in their classical forms. They're still extremely useful in describing reality, but we have to know what parts of reality to describe how. Near black holes, for example, geometry gets really weird, but for many purposes the old Euclidean geometry is adequate.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
    18. Re:"inescapable conclusion" by david_thornley · · Score: 1

      Enough decades ago, you would have found a great many scientists agreeing with you. Since then, the evidence for the big bang has been piling up, and pretty much everybody who's studied the evidence believes there was a big bang.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
    19. Re:"inescapable conclusion" by Strangely+Familiar · · Score: 1
      Those are very good questions, and I don't have the answers. Probably because I don't have a very good definition of what pure logic is, or even if it exists. I struggle with those questions. Obviously, it is better to have eyes to see and ears to hear in addition to a CPU to compute, in order to run physical experiments. I don't know whether, logically, eyes and ears are necessary. Unfortunately, my tiny brain has not reached the limits of pure logic. So I just don't know.

      .

      On the other hand, I believe I have used pure logic to understand some things about space and time. I believed for many years that there was no possibility of a final theory in physics, on the basis of logic. But in 2007, I had a change in my logical thinking, and found a logical error I was making. It was in understanding the limits of my own personal logical abilities that finally convinced me that a final theory was possible. Strangely enough. And, understanding these limits led to conclusions about the nature of space and time. So that's why I said what I said. I still need to publish my findings. I have not found the time and motivation to fully explain them in a manner worthy of publication. OMG, why am I saying these things to an annoymous coward? You will never circle back and read my reply.

      .

      And I must point out that every calculation must obey the laws of physics, even if the interpretation of the way it obeys the laws of physics is not transparent. If there is a complete set of laws, there is only one complete set of laws. Otherwise, it is not the complete set of laws I am talking about. Everything must obey the one complete set of laws. Everything. Every calculation, every thought, every expression, every version of this sentence. All. must. obey. You may not understand how it obeys, or interpret the way it obeys correctly. But everything obeys.

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    20. Re:"inescapable conclusion" by Serenissima · · Score: 1
      So, I'm definitely not a physicist, but I have a question that your comment seems to be at the root of.

      The beginning of the universe does not need to conserve energy, but things as far as we can tell are conserved after that.

      As far as I understand it, we're trying to figure out what's happening on the edge of the expanding universe, but we have no idea what is outside of our universe that it is expanding into. It could be something that doesn't follow any of our laws of physics and is inexplicable, all we know is that it not this universe. If we know our Universe started in NotThisUniverse, and you mention the beginning of the universe does not need to conserve energy, then doesn't it follow that energy came from NotThisUniverse? And possibly, once here our laws of physics allowed for the creation of a stable universe? If so, could we explain the vacuum energy as saying that the expansion of our universe into NotThisUniverse is allowing the conversion/transfer/creation of energy from NotThisUniverse "stuff" to our universe stuff?

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    21. Re:"inescapable conclusion" by Methadras · · Score: 1

      In effect, space itself is a perpetual motion machine.

    22. Re:"inescapable conclusion" by JimFive · · Score: 1
      Great post and thanks for the explanation. I do have one nitpick, though

      (which is what the equation that governs the cosmological expansion of spacetime)

      The equation does not govern the expansion, the equation describes or models the expansion. In the same way that the map is not the territory, the math is not the universe.

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      JimFive

      --
      Please stop using the word theory when you mean hypothesis.
    23. Re:"inescapable conclusion" by towermac · · Score: 1

      I also agree with the evidence, and will be shocked if I win that dollar. But I do find the speculation interesting.

      I'll disagree with piling up. We got red shift and the CMB, as far as evidence goes. That's about it.

      Not everything would change with steady state, you'd just have to start with explaining those two things. And yes, a few theories of interest to nerds would change from those changes.

      Here's a thought, the gravitational constant was part of Einstein's steady state universe. He was convinced otherwise, yet we still have it. What if it's not constant? What if 'tired light' is the result of travelling through varying values of g? It should be a constant. We even named it that. But we don't know that to be a fact. It's a theoretical value that appears to measure up when we test it here on Earth.

      On the CMB, yeah I got nothing. Teh big bang explains it pretty well. Which is why this is only fit to post on /. :) Perhaps a steady state infinite universe would also have background noise...

      But a lot of it is theory. I hope we are not painted into an academic corner so that any physics breakthrough has to break everything. I hope that science is not stuck in a rut the same way society is.

      Also, I got Einstein's initial gut feeling helping me win that $1. That's not nothing.

    24. Re:"inescapable conclusion" by strikethree · · Score: 1

      All is one... a sort of field. There is no such thing as matter or space-time. (empirically there is but we will get to that momentarily)

      As this field cools, it begins to separate. As energy "cools" it condenses into "knots of energy" called matter. What is left over from this is called space, but as pointed out previously, should really be called space-time as they are both properties of what is left when you extract "matter" from the One Field.

      Gravity does not exist (empirically it does). It is merely an artifact of time in relation to "matter". There is no quantum foam (empirically there is), that is merely an artifact of the One Field trying to be one again.

      It is your empirical knowledge that is making it so hard for "mankind" to see the truth of it all.

      Signed,
      Knar Goowoos from the Spiro galaxy in the year as you reckon it 87,948.6

      --
      "Someone needs to talk to the tree of liberty about its ghoulish drinking problem." by ohnocitizen
    25. Re:"inescapable conclusion" by Rich0 · · Score: 1

      There was a beginning to the universe (which alone breaks the symmetry: you can't shift backwards in time more than ~13 billion years)...

      Well, it might be better to say that we have no scientific knowledge of what came before the big bang, and as best as we can tell it is impossible to ever obtain knowledge of what came before.

      It is convenient to call this a "beginning of time" or something like that, but this is a bit of a contrived definition.

      But, as has been pointed out elsewhere in this thread our definitions of things like space and time are already pretty tenuous in general. We're very good at predicting the results of experiments, but we're not so good at really understanding why the universe actually works the way it seems to. The equations don't really provide much insight into what is actually happening.

  2. Sure some theories will change but... by crioca · · Score: 5, Funny

    The only thing that's tearing cosmology apart is the gradual expansion of space.

    1. Re:Sure some theories will change but... by Anonymous Coward · · Score: 1

      The electric universe folks are not taken seriously because their ideas violate almost all known laws of physics without showing how they should be modified and without accounting for existing measurement data. They have also made no testable predictions that have turned out to be true.
      The basic problem is that they aren't knowledgable enough about the field in which they are dabbling. This then leads them to make a lot of simple mistakes which they cannot spot themselves because they don't know the things which are inconsistent with their ideas and which need to be accounted for.

  3. I don't get it by slashmydots · · Score: 4, Interesting

    If there are no particles moving at all, how does empty space have energy? It's the textbook definition of lack of energy. Empty space cannot impart energy on matter and it can't spontaneously create matter. There's some theory about virtual particles but their net energy is zero when they combine so that's not it. Can anyone explain why empty space has energy?

    1. Re:I don't get it by Black.Shuck · · Score: 1

      Can anyone explain why empty space has energy?

      Nope, but we have a name for it anyway: Dark Energy.

    2. Re:I don't get it by smooth+wombat · · Score: 4, Informative

      how does empty space have energy?

      That was my question as well until I read Brian Greene's explanation in his book, The Fabric of the Cosmos.

      In short, the Higgs Field. Long answer, think of what we call space as a fabric (hence the title of his book). The Higgs Field is the fabric upon which everything else "sits". Even if there are no particles in a given unit of space, it is not empty because the Higgs Field is still there.

      Start on page 254 of his book and work your way through as he describes the field and how it (supposedly) permeates everything.

      --
      We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
    3. Re:I don't get it by fyngyrz · · Score: 1

      Because empty space is full of particles

      No, see, by definition, that's non-empty space. Empty space is... empty.

      --
      I've fallen off your lawn, and I can't get up.
    4. Re:I don't get it by Anonymous Coward · · Score: 1

      In short, the Higgs Field

      There is nothing special about the Higgs field in that regard. Field theories in general will attribute energy to the vacuum. Just plain old quantum electrodynamics dealing only with fields for photons, electrons and positrons will have a vacuum energy. The Higgs field contributes to that, but it is not the only part, as the Standard model and a lot of related things are all field theories with many all-permeating fields. (Also why comparing Higgs field to the aether is annoying, because such people typically never heard of other fields, quantum or classical.)

    5. Re:I don't get it by duke_cheetah2003 · · Score: 4, Funny

      Start on page 254 of his book and work your way through as he describes the field and how it (supposedly) permeates everything.

      This just instantly makes me think of "The Force."

    6. Re:I don't get it by Gavagai80 · · Score: 1

      Particles are not all touching each other, so the distance between them is necessarily considered empty. The space between a nucleus and electrons in an atom, the space between different atoms, etc. These spaces have field energy but no particles so they're empty.

      --
      This space intentionally left blank
    7. Re:I don't get it by dbc · · Score: 1

      George Lucas in Love https://www.youtube.com/watch?...

    8. Re:I don't get it by slashmydots · · Score: 1

      Resist means it had opposite direction energy and since it doesn't then...space has no energy. I still don't get it.

    9. Re:I don't get it by Bengie · · Score: 1

      Virtual particles do impart force. My understanding is that it is a net of zero, Universe wide, but maybe not locally. Virtual particles can push two plates together, and create torque issues with nano-structures.

  4. Since when did unknown == paradox?? by khchung · · Score: 5, Interesting

    Perhaps the most dramatic of these paradoxes comes from the idea that the universe must be expanding. [...] yet nobody knows how this can occur.

    Since when did "paradox" became a synonym for "unknown"?

    Yeah, nobody knows how space expands, but how does that make it a "paradox"?

    --
    Oliver.
    1. Re:Since when did unknown == paradox?? by Dastardly · · Score: 5, Informative

      Paradox - "a statement or proposition that, despite sound (or apparently sound) reasoning from acceptable premises, leads to a conclusion that seems senseless, logically unacceptable, or self-contradictory."

      The paradox is that energy is supposed to be conserved, but space has energy and is increasing. So, we have a logically unacceptable a conclusion.

      Just because it is a current paradox doesn't mean it can never be resolved. We find an energy source, or figure out the laws of physics which in this case allow for the creation of energy and is stops being a paradox.

      Quantum physics calculations say the vacuum energy is one value while measurements of the curvature of the universe say it is a different value. That is a paradox especially when both Quantum physics and the physics involved in measuring the curvature of the universe seem to both be right in other respects such that making changes to resolve this paradox causes them to stop describing other things accurately. So, we have logically unacceptable conclusion.

      The red shift thing doesn't look like a paradox, but a really cool test of our understanding of cosmological red shift.

      And, the homogeneity problem could be a paradox linearity of expansion says the universe is homogenous, observations say it is not. But, they don't mention whether observations have done a reasonable job of determining the dark matter distribution of the universe.

      There are paradoxes in the article, but it does drift into one topic that is not a paradox and another that is borderline.

    2. Re:Since when did unknown == paradox?? by phantomfive · · Score: 1

      It's a paradox because everything we know says it can't happen.

      In other words, if a paradox is a contradiction, then here we have all the evidence that shows something can't happen, plus evidence that shows it is happening.

      --
      "First they came for the slanderers and i said nothing."
    3. Re:Since when did unknown == paradox?? by Strangely+Familiar · · Score: 2

      If an unknown paradox fell on top of a tree falling in the woods, but no philosophers could debate the paradox since it was unknown, would it affect whether the tree makes a sound?

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    4. Re:Since when did unknown == paradox?? by msauve · · Score: 1

      Does a philosopher shit in the woods?

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    5. Re:Since when did unknown == paradox?? by sjames · · Score: 1

      It just means there's something we don't know. The energy comes from something, much like potential energy can become kinetic energy.

    6. Re:Since when did unknown == paradox?? by phantomfive · · Score: 2

      Yeah, investigating the paradoxes is one of the most fruitful methods of scientific inquiry and new understanding.

      The counterpoint to that is, speculation about paradoxes is one of the most fruitful methods for nutcases and weirdos.

      --
      "First they came for the slanderers and i said nothing."
    7. Re:Since when did unknown == paradox?? by phantomfive · · Score: 1

      Indeed, that is the answer to almost every paradox.

      --
      "First they came for the slanderers and i said nothing."
    8. Re:Since when did unknown == paradox?? by circletimessquare · · Score: 1

      only if no one hears him

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    9. Re:Since when did unknown == paradox?? by sjames · · Score: 1

      True, but paradox is a rather strong word to use in this case. Usually a paradox involves a careful chain of logic that inexorably leads to an absurd conclusion. Particularly when the flaw of reasoning eludes careful examination.

    10. Re:Since when did unknown == paradox?? by Strangely+Familiar · · Score: 1

      Obviously paradoxes are not real so examine the paradoxes...

      If paradoxes are not real, how do we examine them? How do we even know about them, if they are not real? If they are not real, they must not really exist. So, are you saying the only true paradoxes are the ones we don't know about and which don't exist? Wow. I think I get it now. It has been 42 all along, but 42 is just a number. 42 isn't a real thing, and that is the true paradox. I don't know the answer, because paradoxes are not real, which means I do know the answer, which is 42.

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    11. Re:Since when did unknown == paradox?? by phantomfive · · Score: 1

      That's certainly one use of the word!

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      "First they came for the slanderers and i said nothing."
    12. Re:Since when did unknown == paradox?? by towermac · · Score: 1

      That's a bit harsh, isn't it? Wouldn't you say that investigations start with speculation?

    13. Re:Since when did unknown == paradox?? by joe_frisch · · Score: 1

      Agreed. Also, if you someone is worried about conservation of energy you have to worry about the big-bang - where everything suddenly appears.

      We don't yet have a good theory that includes quantum mechanics and gravity - and that seems to be central to all of these unknowns. Likely we will figure one out eventually.

      Most of the issues with quantum gravity occur at scales that are not accessible in the laboratory. Every experiment we can do is predicted by existing theories, and we can't reach the conditions where we expect those theories to fail.

    14. Re:Since when did unknown == paradox?? by phantomfive · · Score: 1

      Indeed it can, but if speculation is all you do, if you don't try to attack your own ideas, then you're going to get off into the weirdness.

      --
      "First they came for the slanderers and i said nothing."
    15. Re:Since when did unknown == paradox?? by david_thornley · · Score: 2

      There are things called paradoxes in relativity, which tend to be people thinking in Newtonian terms part of the time.

      The twin paradox: Harold stays on Earth, while George (separated at birth) travels at relativistic speeds for a while and then turns around and comes back. Despite the fact that from George's point of view Harold and the Earth went away and came back, George is nevertheless younger. (Harold's using the same frame of reference all the time, being unaccelerated - and we ignore general relativity here, because its effects are minor. George uses two different reference frames, one going out in which Harold is younger, and one coming back where Harold is older, and changes between the two while turning around.)

      The pole-in-barn paradox: Fred has a twenty-foot pole, and is running at relativistic speeds towards a ten-foot-wide barn. From the barn observer, Fred's pole shrinks to ten feet, and thus fits into the barn, while Fred sees the barn shrink to five feet wide and his twenty-foot pole can't possibly fit. (Having the pole fit inside the barn means that its front end fits into the barn at the same time the back end does. With Special Relativity, "at the same time" isn't really meaningful, so Fred sees the front end of the pole at the far end of the barn before he sees the back end of the pole at the near end of the barn, while the barn cat sees the timing differently.)

      So, paradoxes happen when we're thinking about something in the wrong way. The current problem we've got is that we have two ways of looking at the Universe, both with very large amounts of precisely corroborating evidence, and at least one of those is the wrong way to look at certain things.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
    16. Re:Since when did unknown == paradox?? by strikethree · · Score: 1

      The paradox is that energy is supposed to be conserved, but space has energy and is increasing.

      There is no paradox here. As matter increases, so does "empty space". The energy is an artifact of this separation of matter and space-time. Matter and space-time want to recombine. The real question here is why did matter and space-time disambiguate to begin with.

      --
      "Someone needs to talk to the tree of liberty about its ghoulish drinking problem." by ohnocitizen
  5. Slashdot, byebye! by Anonymous Coward · · Score: 1

    Yet you continue to visit, click, AND post.On almost every article!

    How do you do it?

  6. avogadro's constant and particle density in space by lkcl · · Score: 1, Interesting

    throw-away comment, here :) i did a funny little bit of experimenting a couple of years back, when someone posted here an article about the density of deep space (the number of atoms per cubic metre) having been measured. anyway, remembering my o-level chemisty and i went, "hmm... that's interesting: i wonder if there's a relationship between that particle density and avogadro's constant.

    so... i went... density = 7 * 10e-26, avogadro's const = 6.023 * 10e23, multiply the two together you get 4.2154. just for fun take the cube-root and oo! you get 1.6153982. now, to within experimental uncertainty of the measurements made of the density of deep space vacuum, that number should instantly be recogniseable +/- a bit, as the golden mean ratio (1.618 etc etc).

    so we have a relationship - which has absolutely no quotes real quotes meaning whatsoever [ traditionally called "numerology" in a disparaging way in the physics community... ] between the density of particles in vacuum, avogadro's constant, and the golden mean ratio, in a formula that has very low kolmogorov complexity (https://en.wikipedia.org/wiki/Kolmogorov_complexity). which, as i do not have the kinds of hang-ups that the physics community has about these kinds of things, i find to be... beautiful.

    and that's in and of itself enough for me. i don't care what the physicists say :)

    anyway, as this is slashdot, i thought i'd happily derail the conversation with a nice bit of random semi-related nonsense, and see if anyone notices...

  7. Warning: Another stupid medium.com link by Anonymous Coward · · Score: 1

    I really wish Slashdot would stop accepting their links

  8. it can always be by Revek · · Score: 1

    paradoctored

  9. because science by Swampash · · Score: 1

    Coming up with better explanations is what science is for.

    Summary: headline is sensationalist clickbait, Slashdot editors are whores, Netcraft confirms Slashdot is dying.

  10. Re:"Light drag?" by Dastardly · · Score: 2

    This does happen, although I am not sure if it is seen in red shifts. It is definitely seen in the Cosmic Microwave Background where large cold spots are thought to be due to voids along the line of sight that the CMB photon traveled. I presume a similar effect would apply to any photon crossing that void.

  11. Re:Slashdot, byebye! by Anonymous Coward · · Score: 3, Funny

    Yet you continue to visit, click, AND post.On almost every article!

    How do you do it?

    And you reply to your own post too...

    I know the answer, you are a robot, I mean, I am a robot, oh god.... NO CARRIER...

  12. If the universe is a simulation energy is variable by Paul+Fernhout · · Score: 2, Interesting

    http://www.simulation-argument...

    But, that does not make it any less real-seeming to all of us being simulated...

    And of course, the universe simulator could be simulated, etc....

    It might be simulated turtles all the way down. :-)

    --
    A 21st century issue: the irony of technologies of abundance in the hands of those still thinking in terms of scarcity.
  13. Re:"Light drag?" by megahurts.gr · · Score: 3, Informative

    I am not a physicist myself, but physics is a very interesting topic for me. A long time ago I theorized along these lines, and when I spoke about it with physicists, they told me that my hypothesis has already been considered, and it has a name, and that name is "tired light".

    See "tired light" on Wikipedia: https://en.wikipedia.org/wiki/...

    --
    This guide is definitive. Reality is frequently inacurate. (from THHGTTG)
  14. Maybe the created "energy" is really entropy by Burz · · Score: 2

    As entropy in the universe increases, so does the amount of space.

  15. Re:Gravity is the weakest force by Anonymous Coward · · Score: 1

    Yep. This is the reason I check in with the 'electric universe' folks now and again, to see what their explanations of some of this stuff is. Not that I think they're the ones with correct theories, but the 'mainstream' scientists sure seem to be in love with gravity to explain everything.

    Oh, and if I hear another scientist go on and on about how theories should be "simple and beautiful" I shall vomit. The universe doesn't care what humans think is simple or beautiful. Frankly, the universe being an insanely complex clusterfuck would explain a lot.

  16. Solution to the "vacuum energy" problem by mdenham · · Score: 1

    The expansion of the universe is fueled by a continuous transition to lower-energy vacuum states. Unlike the normal "false vacuum" model, though, there are a lot of these lower-energy states, which become closer and closer together until they reach a limiting value.

    The graph of these states would probably look familiar - it's similar to the electron transitions for the hydrogen atom, only with the orbitals replaced with "time since the Big Bang". The net result matches the lower value of the vacuum energy... and there's the possibility that this also explains inflation as being equivalent to the transition between n=1 and n=2 (whereas we're currently at something on the order of n=10^35).

    Granted, there's no guarantee that I'm right (and in fact I'm probably not, since I have no formal training in cosmology), but it looks like a model that fits the current knowledge.

  17. not paradoxes by Khashishi · · Score: 1

    Those aren't paradoxes. So space is created. How is that a paradox? Did someone say space is not allowed to be created?
    So energy is created. That violates conservation of energy, but conservation of energy is simply a law that we formulated from experience, and later proved using Noether's theorem by assuming that the laws of physics are time-invariant. Well, it's not valid to extrapolate from our small-scale experiences to the universe, and the laws of physics probably aren't time-invariant at cosmological scales.
    Nobody really knows how to calculate the energy of the vacuum, and that's why we have to use renormalization. The 10^120 figure is really a very rough ballpark estimate using dimensional analysis. There's not any solid theory to back it up.

    1. Re:not paradoxes by serviscope_minor · · Score: 1

      There is a paradox in that the laws of physics simultaneously say that energy is being created and it can't be created.

      Well, it's not valid to extrapolate from our small-scale experiences to the universe, and the laws of physics probably aren't time-invariant at cosmological scales.

      And therein lies the source of the paradox: it arises because our understanding is incomplete.

      --
      SJW n. One who posts facts.
  18. Re:avogadro's constant and particle density in spa by DavidRawling · · Score: 1

    Noticing does not mean we care :).

    Karma -= 100...

  19. Energy is not conserved in General Relativity by As_I_Please · · Score: 5, Interesting

    It has been known for quite some time that energy is difficult to define rigorously in General Relativity. A good explanation can be found in this post by CalTech physicist Sean Carroll. Key point:

    The point is pretty simple: back when you thought energy was conserved, there was a reason why you thought that, namely time-translation invariance. A fancy way of saying “the background on which particles and forces evolve, as well as the dynamical rules governing their motions, are fixed, not changing with time.” But in general relativity that’s simply no longer true. Einstein tells us that space and time are dynamical, and in particular that they can evolve with time. When the space through which particles move is changing, the total energy of those particles is not conserved.

    As a simple example, imagine a photon traveling through an expanding universe in a region with no other matter or energy (dark or otherwise). The expansion of space stretches the wavelength of the photon (cosmological redshift, which is distinct from Doppler redshift), causing it to lose energy. The photon loses energy with nothing around it gaining. Energy is lost because spacetime itself is changing, so Noether's theorem doesn't apply.

    1. Re:Energy is not conserved in General Relativity by As_I_Please · · Score: 1

      Note that the linked blog post was in response to another Arxiv Blog article that makes the same mistake.

    2. Re:Energy is not conserved in General Relativity by Anonymous Coward · · Score: 2, Interesting

      When the photon's wavelength is integrated over the entire, expanding volume, is the energy still non-conserved? Sure, the kinetic energy depends only on the wavelength, but doesn't the photon also have a gravitational field whose source (energy) now occupies more space? Is the associated gravitational energy the integrated deformation of the space-time in which it resides? The deformation density has decreased with decreased kinetic energy density, but the deformation now exists over a larger region of space-time.

    3. Re:Energy is not conserved in General Relativity by Anonymous Coward · · Score: 1

      Energy is lost because spacetime itself is changing, so Noether's theorem doesn't apply.

      If you reverse time, both in the metric and the travel of the photon, you would get a photon that gains energy. There is still a time reversal symmetry there. Also if you treat the energy imbued by the creation of the universe as a form of potential energy, the photon is exchanging energy with that, just as a photon coming out of a gravity well red shifts.

    4. Re:Energy is not conserved in General Relativity by PJ6 · · Score: 1

      As a simple example, imagine a photon traveling through an expanding universe in a region with no other matter or energy (dark or otherwise). The expansion of space stretches the wavelength of the photon (cosmological redshift, which is distinct from Doppler redshift), causing it to lose energy. The photon loses energy with nothing around it gaining. Energy is lost because spacetime itself is changing, so Noether's theorem doesn't apply.

      I wonder if we could add a scale-invariant component, and make the lost energy just a property of measuring it in a non-inflating reference frame.

      Or, I should say, I wonder what contradictions that would lead to.

    5. Re:Energy is not conserved in General Relativity by As_I_Please · · Score: 1

      Consider the region of space that contains the photon. If each dimension of the universe double in size, then the photon loses half its energy. But, the vacuum energy increases by a factor of 8 (volume increases by 8 since space is 3 dimensional). This process can't keep energy constant.

      You can also reason that different photons will lose different amounts of energy depending on the energy they started with. There's nothing to keep these changing energies balanced with the vacuum energy in expanding or contracting space.

    6. Re:Energy is not conserved in General Relativity by As_I_Please · · Score: 1

      Read the blog post I linked to above. There's no way to consistently assign an energy density to spacetime curvature. Quoting Prof. Carroll:

      [U]nlike with ordinary matter fields, there is no such thing as the density of gravitational energy. The thing you would like to define as the energy associated with the curvature of spacetime is not uniquely defined at every point in space. So the best you can rigorously do is define the energy of the whole universe all at once, rather than talking about the energy of each separate piece. (You can sometimes talk approximately about the energy of different pieces, by imagining that they are isolated from the rest of the universe.) Even if you can define such a quantity, it’s much less useful than the notion of energy we have for matter fields.

    7. Re:Energy is not conserved in General Relativity by As_I_Please · · Score: 1

      True, in a contracting universe, photons gain energy. Noether's theorem says that energy conservation is a consequence of time translation symmetry (t -> t + constant), not reversal symmetry (t -> -t), so conservation of energy isn't required. The "energy imbued by the creation of the universe" seems ill-defined. If you believe Hawking and Krauss, this energy is zero.

    8. Re:Energy is not conserved in General Relativity by As_I_Please · · Score: 1

      There is no Doppler effect for a single photon, unless that photon is emitting other photons.

  20. Seems... facile by fyngyrz · · Score: 2

    How can we definitively tell if the vacuum over there has the same energy density as the vacuum over here?

    Further, how can we tell if the energy we think we find in vacuum here isn't energy that arises from particulate contamination? Or, for that matter (ha) is coming from somewhere else? Has someone managed to (a) create a perfect vacuum and (b) measure its energy and (c) determine that whatever was measured as appearing at X, definitely hadn't disappeared from all the possible Ys? Somehow, I doubt it. If for no other reason than our access to some of the other Y (say, around Andromeda) is... limited. As well as non-contemporaneous -- if something disappeared from that region, to appear here, we wouldn't have any indication it had happened for about 2.5 million years. And even then, our ability to measure vacuum precisely at that distance... not so good.

    My (admittedly not very deep) understanding of vacuum is that it is defined by a lack of content, and that a perfect vacuum would be defined by a perfect lack of content -- and were that simplistic idea correct, then I don't see why how much perfect vacuum there is has any bearing at all upon the total amount of energy.

    And, if vacuum is indeed empty when perfect, but we think there is energy detected in what we consider a perfect vacuum, then perhaps we're simply misinterpreting the goings-on within an imperfect vacuum. Perhaps there is more to get rid of than the molecules and particles we know of at present.

    Or, perhaps space is infinite and at least somewhat plastic to start with, and our situation (going with the idea that the space we can observe seems to be expanding) is more like adding a thimble of water to a planetary ocean (let the ocean conceptually be infinite for the sake of an example.) Perhaps space over there is contracting, while space over here is expanding.

    My own position is that any cosmological proposal that includes the phrase "arose from nothing" or similar is probably better filed under astrology until actual evidence is found of the idea -- not possible precursors or echos, but an actual example of what is being described. We seem to be pretty clear on the idea that matter and energy are essentially interchangeable, and we have no experimental data that proves stuff arises from non-stuff, so at least at this point, I see no reason to take an assertion of "arose from nothing" seriously.

    --
    I've fallen off your lawn, and I can't get up.
    1. Re:Seems... facile by Anonymous Coward · · Score: 1

      The energy of the vacuum HERE would be decreasing over time, and so far there is no evidence that's the case.

      And the thing is, there is no such thing as "perfect vacuum".
      http://en.wikipedia.org/wiki/Quantum_foam

      Also, more on the original question:
      http://en.wikipedia.org/wiki/Vacuum_energy
      http://en.wikipedia.org/wiki/Pair_production

    2. Re:Seems... facile by Anonymous Coward · · Score: 4, Informative

      How can we definitively tell if the vacuum over there has the same energy density as the vacuum over here?

      Measurements of expansion rate from distances and from the CMB closely match models that have a constant energy density per unit volume. That is about as simple as it gets for the moment. Until there is good justification for why we would expect the energy to be different at different places, whether from large scale measurements, or theories about small scale things like QFT, there is no basis to assume things are different. But there is always the possibility things are more complicated than they seem.

    3. Re:Seems... facile by Anonymous Coward · · Score: 5, Interesting

      There's also no evidence that energy is being created.

      This!

      Given how quantum non-locality appears to work, we can in some cases be forced to consider that the energy in question is distributed until it becomes "not distributed" by some process that collapse it's superposition. Examination by most physical measurement processes does this.

      Even though Einstein abhorred the implications of quantum theory, his own general approach to working out relativistic theory stands, which is to base our examinations of the universe on 2 things:

      1- That which we observe and can confirm by experiment and
      2- The implications of what we observe and can confirm by experiment which then must be observed and confirmed by experiment.

      I do agree that there is a point where each explanation ceases to function to explain the whole, newtonian physics functions to explain how macroscopic objects behave to a certain precision and it breaks down when the curvature of spacetime is altered by extreme amounts of mass in a small place or limited masses being accelerated to such speeds that they require descriptions of how they alter spacetime by effect to be described properly. This description breaks down when we attempt to explain objects existing at the sub atomic level and a whole other set of rules come into play that exist in between the frames of the macroscopic and relativistic linear framework we are used to using to describe things. Beyond this we are at the point where we do not have the tools yet to perform experiments we need to test the implications of the things which we have observed at that level.

      Sometimes analogies can be helpful, sometimes they can just confuse the issue. In the case of expanding space, I prefer to think of it as something analogous to plate tectonics, We know the Earth is not expanding, but we know that the floor of the Atlantic ocean is getting wider and wider across geologic time scales, matter is not being created, but the distance between the coastlines of the eastern United States and Western Europe gets a little larger each century. When considering vacuum energy I think of the plate tectonics analogy and remember that even though it seems like the vacuum energy should be becoming more vacant, the implications of what we observe in the Hadron collider confirms that when taken altogether, the total amount of energy in the universe balances out to zero and comparing different sized slices of this pie to one another confuse the issue.

    4. Re:Seems... facile by fyngyrz · · Score: 3, Insightful

      The energy of the vacuum HERE would be decreasing over time,

      You can't assume that everything everywhere behaves the same. You can't assume that energy drawn from one location will show up as a deficit in another (you find running water in the street's gutter... you learn Joe's pool is draining. Assuming Mark's pool is also draining doesn't follow.) You can't measure anywhere but (very) locally, which also means you can only measure data very near temporally -- and so you really have no bloody idea what is going on without resting your conclusion on assumptions made entirely free of supporting data.

      What you're claiming is equivalent to saying you know exactly what's going on on a planet orbiting some star in Andromeda because you've done some observations as to what is going on here. Evidence is utterly insufficient to your claim.

      --
      I've fallen off your lawn, and I can't get up.
    5. Re:Seems... facile by fyngyrz · · Score: 2

      Nah, I just bought one from Dyson. Works great!

      --
      I've fallen off your lawn, and I can't get up.
    6. Re:Seems... facile by mattpalmer1086 · · Score: 3, Interesting

      IANAP, but my admittedly also very shallow understanding, is that when we're talking about the energy of the "vaccuum", we mean "energy associated with space itself".

      A vaccuum is typically defined by the absence of matter in a volume of space (but not necessarily light or other energy). But let's exclude those too - there is no matter or electromagnetic radiation at all.

      Even with those exclusions, at a fundamental level space appears to be a seething maelstrom of quantum particles popping in and out of existence. There seems to be some energy associated with "empty" space.

        Some people posit that the vaccuum (i.e. space as we know it) may be "unstable" - that the particular energy it possesses could be lower than it is - and that we're just caught on a local bump in the energy landscape. If the vaccuum ever "fell off" that bump to a lower level, it would apparently spread at the speed of light across the entire universe from wherever it started, destroying everything that currently exists, and leaving behind... I don't know what. More vaccuum, but with a much lower energy associated with it, and with lots of new matter and energy created by the release of the vaccuum energy. Probably.

      Anway, happy for a real physicist to correct me on some or all of the above - that's just my very lay understanding of what is meant by vaccuum energy.

    7. Re:Seems... facile by lonecrow · · Score: 1

      Perhaps the energy is being diluted as it expands. But since the measuring stick being used to measure it is part of the system that is expanding/diluting, it appears constant.

    8. Re:Seems... facile by fyngyrz · · Score: 1

      Yes, I do. Because we have no such evidence; we can't make the measurements it would take to get said evidence.

      You are confusing assumption with evidence. They are not the same.

      --
      I've fallen off your lawn, and I can't get up.
    9. Re: Seems... facile by MickeydotFinn · · Score: 1

      Is it that Sphere model I keep hearing about?

    10. Re:Seems... facile by Methadras · · Score: 2

      Well, there are Cassimir effect experiments done in a vacuum that show energy is coming from somewhere. Someplace we can't see. Is it from repository universes that contain the building block materials for this universe that leak through the aether/ether of space? Is that what dark matter/energy really is? Is it's radiation the fundamental particles we see now? I don't know, but what I do know is that it isn't facile.

    11. Re:Seems... facile by fyngyrz · · Score: 1

      You have not refuted any point I made.

      What is the energy level of a cubic foot of space exactly 1 light year past the furthest star on a line directly away from us that is still technically in Andromeda? Presuming you could supply that information (you can't) can you assure me that said cubic foot is in no way contributing to the particular flux of a cubic foot of space one light year the other way? (you can't.)

      So the delusion you're carrying around that you know what's going on and are able to definitively say so in such a way as to pooh-pooh my questions is unmasked, and all your complaints resolve to nothing.

      I'll be blunt: There are NO "biggest results" in astrophysics that can answer those questions. Consequently, any answers you claim to have in that regard are, at best, evidence-free supposition.

      --
      I've fallen off your lawn, and I can't get up.
    12. Re: Seems... facile by fyngyrz · · Score: 1

      Lemme look... on the vortex container (you know, where all the dirt swirls around), it says "US Mobius Glass, 4th dimension containment division. Certified for virtual particles only."

      That help any?

      --
      I've fallen off your lawn, and I can't get up.
    13. Re:Seems... facile by negablade · · Score: 1

      How can we definitively tell if the vacuum over there has the same energy density as the vacuum over here?

      This comes from measurement of the fine structure constant. The virtual particles created as a result of the vacuum energy interact with electrons, causing small changes in the elementary change of the electron, and int he electromagnetic coupling between charged particles. This effect is accounted for in QED, and has been observed in the spectra of Hydrogen as difference in the energy levels of 2S1/2 and 2P1/2 orbitals (http://en.wikipedia.org/wiki/Lamb_shift). Measurement of the fine structure constant from atomic spectra allows us to measure if the elementary electric charge has changed over time or at different locations in the universe, essentially a remote measurement of the uniformity of vacuum energy.

      Some measurements do suggest that the fine structure constant has changed over time, or that it isn't uniform throughout space over galactic scales. Indeed, there is no reason why it should be. That said, I would be surprised if the inhomogeneity is balanced by the accelerating expansion rate of the universe. Hence the problem of apparent increase in energy and violation of conservation of energy.

  21. Re:avogadro's constant and particle density in spa by iluvcapra · · Score: 5, Informative

    Even professional physicists like some good numerology sometimes.

    Also, just so we're clear, you took a number e-26, multiplied it by a number e+23, and you ended up with a number e+0?

    --
    Don't blame me, I voted for Baltar.
  22. YIC by fyngyrz · · Score: 1

    It might be simulated turtles all the way down.

    It's virtual turtles, you insensitive clod!

    --
    I've fallen off your lawn, and I can't get up.
  23. Units. by Anonymous Coward · · Score: 1

    Units. I could just as easily started with the density = 1 or density = pi. Units matter, your conclusions don't work in ALL units. Then taking the cube root of a number just for fun? Do you mean to say "just to get the answer I want?" What is the point of this series of calculations?

  24. Re:avogadro's constant and particle density in spa by msauve · · Score: 1

    It's "new math." You don't have to show your work.

    --
    "National Security is the chief cause of national insecurity." - Celine's First Law
  25. How did this get modded up? by Anonymous Coward · · Score: 4, Informative

    I remember something like this vaguely coming up in a comment before on Slashdot, and I hope it was not you making the same mistake, as comments spelled out in those cases clearly that it was a case of density * avogadro's constant / number of atoms gives you the average atomic mass, which is pretty close to 1 for deep space.

    so... i went... density = 7 * 10e-26, avogadro's const = 6.023 * 10e23, multiply the two together you get 4.2154. just for fun take the cube-root and oo! you get 1.6153982

    No, you multiply those two numbers together, and you get 0.042, which is also a meaningless value because you now have kg/m^3/mol... and it is not like deep space is anywhere near a constant density, as there is a large variation in density and temperature (read about warm intergalactic medium vs. hot intergalactic medium).

    I don't know how this got modded up. Not saying it should have been modded down, but you just took two random numbers, one of which doesn't even have that deep of a connection to space as you imply, and multiplied them together incorrectly, and tried to draw vague conclusions from that.

    1. Re:How did this get modded up? by david_thornley · · Score: 2

      A mole is a certain number of particles, not a physical unit in its own right. Multiplying the density times avogadro's constant (assuming you're allowing for molecular weights, which is about 1 gram for a mole of monoatomic hydrogen) is the right way to find the number of particles.

      Of course, (a) OP got his or her decimal place screwed up, (b) density does vary widely, and (c) given an arbitrary number, if you try enough ways to manipulate it, you're going to come up with something reasonably close to an interesting number eventually.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
    2. Re:How did this get modded up? by david_thornley · · Score: 1

      Avogadro's number (along with molecular weight) is precisely what you need to convert between mass per unit volume and number of particles per unit volume. For monoatomic hydrogen, multiplying grams per unit volume by it gives you the number of particles per unit volume pretty precisely. A mole of particles is a certain number of them, not a unit in itself.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
  26. Back to the 1920's? by Anonymous Coward · · Score: 1

    When hubble was making his observations, there were a whole series of alternative proposals to explain spectral redshift. To the best of my knowledge, these have all been abandoned, but a viable alternative to expansion wraps up many of these paradoxes, and honestly, makes the universe much less depressingly overcomplicated.

  27. splosions by jeoin · · Score: 1

    seems to me that any time i have seen an explosion there has been a large bubble or series of bubbles, and a bunch of instant energy just heading out.

    --
    Jeoin
  28. Re:Slashdot, byebye! by Jane+Q.+Public · · Score: 1

    OP says "paradox" but the issues discussed in the paper are not strictly paradoxes, just contradictions. There is a difference.

    If you say it's black and I say it's white, that's not a paradox but a contradiction. If one theory says it's red and another theory says it's green, again that's not paradox but mere contradiction.

  29. Three fundamental paradoxes by govett · · Score: 1

    * Why does something exist rather than not? * What is time? * Why do people laugh at Don Rickles?

  30. Re:Red shift by megahurts.gr · · Score: 1

    This has already been mentioned in a comment above, look for the title "Light drag?".
    A theory of this kind has existed since 1929. See "tired light" on Wikipedia: https://en.wikipedia.org/wiki/...

    --
    This guide is definitive. Reality is frequently inacurate. (from THHGTTG)
  31. Re:Slashdot, byebye! by Anonymous Coward · · Score: 1

    But if your theory says it should be black but your theory has an underlying assumption of being white, that is a paradox, not merely a contradiction.

    Sadly, generally accepted cosmology theory is a mishmash of general relativity and quantum mechanics which are theories that contradict each other on some predictions. For example FLRW from general relativity predicts the existence of a cosmological constant or some sort of dark energy and suggests that a universe that is expanding at the currently observed rate has a range of values: let's call it black, but cosmology relies on a data from quantum mechanics which given other observations suggests these constants have a completely different range of values orders of magnitude different: let's call it white.

    Sure it's two different theories GR and QM that disagree, but oddly, cosmology theory is a mishmash of the two and thus is more paradoxial than particle physics which knows that GR and QM disagree at small scales about gravity yet are hopeful for a GUT (grand unified theory) at some point to make testable predictions. Most cosmology assumptions aren't awaiting a GUT and you might even say they are effectively embracing the contradicting predictions of GR and QM and blindly marching on.

  32. What if... by kefalonia · · Score: 1

    ...the universe is not expanding, but the observers instead are in an "apparent shrinking" process, which is only manifesting itself in the form of current observations?
    Does that fly in the face of what is presently known?

    Don't shoot the messenger, there is no physicist anywhere around here, just a thought challenger ;-)

  33. The end of both QM and GR? by jandersen · · Score: 1

    I think it is time to revise the foundations of both our great theories, quantum mechanics and general relativity. This has become more and more evident in the recent decade, but it has been obvious almost from the beginning, since the two theories have been known to be incompatible already since the Solvay conference, if not before, and I think I can see some signs that efforts are being made to move away not only from GR, but also from QM.

    The big problem is of course the inescapeable success of both theories; we have yet to discover a clear example of a contradiction of either theory. To my mind, this suggests that it is necessary to be willing try to go beyond the traditional interpretations of the fundamentals of both. There has already for many years been massive efforts to try to modify GR to be more 'quantum', which have not really brought anything obvious to light, so perhaps it would be worth trying to revisit the foundations of QM? Basic tenets like the collapse of the wave-function and similar concepts have always struck me as far too glib to be real explanations. I think it is perfectly reasonable to expect better than that, something that somehow feels more convincing. Not necessarily simple or intuitive in the naive sense, but convincing. Something like the original explanation for Heisenberg's indeterminacy: that because we observe by means of particles, that are actually waves, there is a limit to how precise our observation can be. Please note, I'm claiming that this is the correct explanation, but it illustrates my point: it feels right because we feel we understands the way waves work, and we can perform calculations on much a finer scale than the observation by means of waves permits.

    I think a lot could probably be resolved by understanding more clearly the basics of QM; all the things that feel too much like glib assumptions, questions like what is a particle in terms of physical space (declaiming that it is 'the wave-function' or similar just sidesteps the issue), and what is time (talking about entropy involves a circular argument, IMO) and others. As you can see, I have stated these two in terms that have some bearing on GR; that is not by accident - I think GR is fundamentally more correct than QM.

    1. Re:The end of both QM and GR? by david_thornley · · Score: 1

      People have been trying to revise the foundations of those theories. The problem is that, while we know they're incompatible, it's apparently really hard to come up with a practical experiment where GR says one thing and QM says another. Given the lack of experimental evidence, about all we can do is come up with ideas on how to make them work together (like string theory), see if they match what we already know, and try to figure out how to get testable predictions from them. The real problem is that we can already account for pretty much everything we've managed to observe, just in contradictory ways. Making more observations is getting harder and harder.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
    2. Re:The end of both QM and GR? by jandersen · · Score: 1

      Making more observations is getting harder and harder.

      But that, in a way, is why I think it is necessary to start looking again at some of the things we haven't really got a good enough definition of. I remember Einstein worked at some attempt at defining what a particle is, but I forget which paper; that is the kind of things we need a better understanding of, is my feeling. I think it has always been obvious that 0-dimensional particles are a shortcut, a convenient way of not adrdressing the problem you don't yet have, and the same goes for things like charges and fields - I don't think they are really fundamental properties, only placeholders for an underlying reality that we have yet to discover.

      Alas, all I can do is offer speculation, and probably not all that good either. But how about, if one wished to define something like an abstraction with particle like properties, but based purely on geometry? And since this is pure speculation, we put no restraint on dimensionality and make no assumptions about whether the geometry is particularly simple; whether it is necessary to hold on to smoothness in the mathematical sense, I'm not sure. To sum up, this might be a universe with many dimensions - all the way up to infinity, even - and the geometry might be chaotic (as in chaos theory) or even 'rough' (ie. a non-differential manifold ~ of varying dimensions). Could a 'particloid' be defined as some sort of localised, crinkly geometry, something that can't easily stretch out and fade away? A whirlpool in the turbulent geometry?

      If one were to carry the comparison to turbulence a bit further, could one construct a sort of 'dimension-eating' mechanism involving whirlpools? If you think about wirlpools in turbulent water, they can seem to form 'networks' or structures that seen from a distance appear 2-dimensional; so at lower resolutions they approximate a simpler geometry which seems smoother and of lower dimension. Just idle speculation, I suspect, but one day, when I am tired of working, perhaps I will spend some time on this.

  34. Statistical proof for turtles all the way down by robi5 · · Score: 1

    What's science's answer to this one?

    1. Any sufficiently advanced civilisation can create a simulation (or more) on a grand scale.
    2. In a simulated world, intelligence and construction may arise, eventually leading to sufficiently advanced simulated civilisations
    3. (... after some thousands of recursions, also recognising that there is plenty of 'time' for that because time is an internal variable of the universe in question...)

    The big Q:

    What is the likelihood that in the vast tree of simulated universes, we are sitting at the root?

    Could it be that as a simulated civilisation advances, and invents the microscope and the telescope, and intelligent species proliferate, the simulatING civilisation has to throw more and more hardware at the problem? Or has to invent physics on the go? E.g. pre-Newton and pre-radiotelescopes, a Newtonian world would have perfectly worked, from the viewpoint of the humans, with 'rendered' stars; pre-microscope, maybe bacteria etc. didn't need to exist. The simulator just simulated some sickness or reaction. When the loop tightened, they had to invent something.

    Maybe science stops when there is enough evidence that some things just can't reconcile with one another, or when more and more investment is needed for less and less impactful findings (bosons, very remote galaxies etc.). Maybe a team of scientists one level up are playing pranks or feeling creative. And some other scientists tie their hands and just start some cellular automaton to see where it leads to.

    Isn't thinking this the equivalent of the geocentric or heliocentric world view?

    1. Re:Statistical proof for turtles all the way down by As_I_Please · · Score: 1

      This depends on the possible quality and size of a universe simulation. Is it possible to simulate the entirety of a universe using only a finite subset of that universe?

      If yes, then there are (at maximum) an infinite number of simulated universes and and infinite number of recursively simulated universes. Thus the probability of us being the root/real universe is zero ("of measure zero" if you ask a mathematician). Perhaps the holographic principle comes into play to allow the entire universe to be simulated without using the resources of the entire universe.

      If no, then there can be only a finite number of simulations in the observable universe. Also, each of the simulated universes is a smaller and/or less-precise version of the simulating universe. In this case, there are (at maximum) a finite number of simulated universes and a finite number of recursively simulated universes capable of hosting intelligent life (a cellular automata with only one cell could hardly be called intelligent). In this scenario, there is a non-zero probability that we live in the root/real universe.

      I lean towards no, but I don't have any evidence, just a bias for thinking myself real.

  35. Re:Gravity is the weakest force by Pope+Raymond+Lama · · Score: 1

    Still, as they find slowly their way through what Plasma in space can achieve, mainstream science is blinded by Gravity only suppositions turned into "reality" with an increasingly set of fudge factors. TFA just list a small number of them. But talk someone on the "mainstream" - including just self-presumed scientifically educated persons that the Big Bang perhaps did not take place, and point to the political and social movements inside Science that led to its conformation, and you are as an "heretic" as someone who tries to tell a fundamentalist Christiant that Hell or Heaven may not be the way he have been told.

    --
    -><- no .sig is good sig.
  36. That's my beef against cosmology by Applehu+Akbar · · Score: 1

    It'a the only discipline where 120 orders of magnitude is a slight disagreement.

  37. LOL - Virtual vs. Simulated and acceptance by Paul+Fernhout · · Score: 1

    Taking your comment seriously, :-) are you suggesting simulated seems to imply fake, but virtual implies essentially the same? Maybe there is some related change in social consciousness on these topics reflected by "virtual" becoming a more commonly used word?

    From Wikipedia:
    http://en.wikipedia.org/wiki/V...
    "Virtuality, the quality of having the attributes of something without sharing its (real or imagined) physical form"

    http://en.wikipedia.org/wiki/S...
    "Simulation is the imitation of the operation of a real-world process or system over time."

    Virtual can also potentially be a subtype of simulation:
    http://en.wikipedia.org/wiki/L...

    So yes, simulation does seem to imply more fakeness (imitation) than virtuality (which implies the essence is still there).

    So, I stand corrected! Thank you, fyngyrz! It's virtual turtles all the way down. :-) Sorry for being insensitive about that!

    BTW, I watched this excellent video last night of "Inventing the Future" with Robert Tercek, interviewing Bruce Schneier and Julian Sanchez about pervasive surveillance, drones, and related social changes, and the advertisements were all about Microsoft HoloLens:
    "Next Future Terrifying Technology Will Blow Your Mind"
    https://www.youtube.com/watch?...

    A decade or more ago I saw a video of similar augmented reality demo (Steve Feinberg walking around Columbia university?),.
    http://www.cnet.com/pictures/g...
    "Steven Feinberg (left), a professor of computer science at Columbia University, created the first outdoor mobile augmented reality system using a see-through display in 1996."

    But Microsoft HoloLens looked so much more impressive and integrated, and I can imagine with better head tracking technology like for Oculus Rift, that it would work better. Slashdot has an article on HoloLens from eight hours ago:
    http://tech.slashdot.org/story...

    But in the context of this discussion, Microsoft's "HoloLens" show how the line between "physical" and "virtual" can start to become blurred.
    http://www.microsoft.com/micro...
    "The result is the world's most advanced holographic computing platform, enabled by Windows 10. For the first time ever, Microsoft HoloLens brings high-definition holograms to life in your world, where they integrate with your physical places, spaces, and things. Holograms will improve the way you do things every day, and enable you to do things youâ(TM)ve never done before."

    Reminds me a bit of Red Dwarf and Arnold Rimmer. :-)

    Perhaps many religions are right, and for our situation at least, an omniscient "god" really does know everything we do? And if every timestep of the virtuality/simulation is recorded somehow, then perhaps nothing is ever lost -- except in a stegnographic sense, or perhaps in the sense of having no more significant runtime devoted directly to its continued processing as an entity as it has lost obvious coherence?

    People talk about how any singularity might be more about humans merging with machines then machines taking over, and one can wonder if, the first time, if there was one, virtualizing was more about a merging of physical and simulated/computed/virtualized as with HoloLens than one or the other?

    Anyway, just random thoughts. It is in the nature of virtualization that you can never be sure what layers really surrounds you, so we may never know...

    One other tangential issue:

    --
    A 21st century issue: the irony of technologies of abundance in the hands of those still thinking in terms of scarcity.
  38. But? by janap · · Score: 1

    "Clearly, anybody who can resolve these problems has a bright future in science but may also end up tearing modern cosmology apart."

    But what? Real scientists love it when their models blow apart.

  39. Re:Slashdot, byebye! by kilfarsnar · · Score: 1

    OP says "paradox" but the issues discussed in the paper are not strictly paradoxes, just contradictions. There is a difference. If you say it's black and I say it's white, that's not a paradox but a contradiction. If one theory says it's red and another theory says it's green, again that's not paradox but mere contradiction.

    But I'm here for an argument!

    --
    "What the American public doesn't know is what makes them the American public." -Ray Zalinsky (Tommy Boy)
  40. Original Article by tobiah · · Score: 1

    Looks mostly theoretical.
    https://www.researchgate.net/p...

    --
    "The ability to delude yourself may be an important survival tool" - Jane Wagner -
  41. Re:If the universe is a simulation energy is varia by radtea · · Score: 1

    The simulation argument is nonsense that is only plausible to people who either haven't given it any thought or don't know any physics: http://www.tjradcliffe.com/?p=...

    --
    Blasphemy is a human right. Blasphemophobia kills.
  42. I can offer a solution to the cosmology problem by hAckz0r · · Score: 2
    The answer to the cosmological problem can be found in thermodynamics, and the same solution simultaneously removes the need for Dark Matter, Dark Energy, and explains the origin of the vacuum energy. By partially defining the photon in physical terms Gravity becomes simply a emergent property of spacetime given the existence of vacuum energy and it's interaction with the spacetime curvature. In my paper I logically present an argument for the thermodynamics as a conclusion, and present a theory based on first principals. I defer the complete definition and the photon and structure of spacetime/matter for a later paper, so I apologize in advance for trying to keep the paper small enough to be readable.

    .
    On The Thermodynamics Of General Relativity.
    http://vixra.org/abs/1412.0270

    I have been looking for constructive feedback on these new ideas, so please do so if you have the time. I published this paper simply to get these new ideas out on the table for discussion by the community while I turn my attention to my next paper on solutions to the paradox of Special Relativity, and later the structure of matter and spacetime. The same solution fits all the open issues I know about.
    Thermodynamic Unification Theory https://plus.google.com/u/0/+S...

    1. Re:I can offer a solution to the cosmology problem by megahurts.gr · · Score: 1

      I don't understand a thing, but if I could vote, I would vote +1 "Interesting".

      --
      This guide is definitive. Reality is frequently inacurate. (from THHGTTG)
  43. Re:Gravity is the weakest force by david_thornley · · Score: 1

    One thing is obvious: you and I have not known the same scientists. Are you sure you've talked to scientists about that? It sounds to me more like people who are interested in the results of science and don't understand the process very well.

    And, yes, gravity dominates over long distances. The strong and weak force are actually limited in range, and although electromagnetism is far stronger than gravity it isn't additive: add positive and negative charges together and you get something not strongly affected, and if you try to add only positive together (say) they'll both attract negative and repel each other, resulting in overall roughly neutral charge in a volume. Gravity is additive: put matter together and it will try to clump on its own (less so without electromagnetism to affect behavior at short range), and it will have an increased force over distance.

    --
    "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
  44. Uhm... by nagromlt · · Score: 1

    When water "solidifies" at 0C (less energy), it "expands" its volume... This is not the only substance to do this. I think the problem with that "paradox" is that it is not a paradox at all. It is a reprsentation of the misconception that all "known" things follow the not-so common sense rule that less energy means contraction. 'Ya follow me? It does not break any rules (that I know of) when you understand why this occurs... i.e. Van Der Walls forces, etc.

  45. The essay falis to grasp "infinity" by Paul+Fernhout · · Score: 1

    As with many cosmological argument, that essay called "Imaginary Arguments" by TJ Radcliffe does not prove anything about a potential infinity of nested infinite universes. There is a key hedge there of "given what we currently know of physics". Much of physics (for example the Heisenberg uncertainty principle) is in essence a theory of what we could conceivably learn about the universe and beyond, not actual information on the universe and beyond. Likewise for saying we can see up to a certain distance of some billions of light years in space and time. That tells us essentially nothing about what is beyond those limits. We could, for example, be in an expanding bubble in a larger ocean of such bubbles -- but we could not tell using light-speed-limited electromagnetism. It would take, say, access to universe level bugs or debugger hooks to make an exploit that would let us travel beyond those electromagnetic limits in a human lifetime. :-)

    This is where that essay goes off the rails, when i overgeneralizes the issue of what we can know with what might be out there: "Nor will it do to imagine alternative physics to fix all this up: insofar as the philosopher's argument is to have any claim on our attention at all, it must be based on what we know about the universe we actually live in, not some self-contradictory universe of a philosopher's imagination, where particles and computers behave in impossible ways."

    That may be a useful sentiment by an observer about an observed box, but it is an overly limiting one when talking about things outside a box the observer appears to be in. At the very best, experimental physics can only tell us about the currently "observable" universe within a very small space-time bubble surrounding the current Earth.

    So what if experiments are precise to many digits? When you are dealing with possible infinities and nested universes, anything is possible. It just does not matter how mind-bogglingly large the numbers are, or even if every universe can only simulate 0.5% of itself. The observable universe is already mind-boggling large. What are, say, a few trillion extra zeros tacked on to that regarding data storage needs or time needs for simulations to have billions of virtual turtles simulating nested universes some of the way down? :-)

    Or in other words, from xkcd:
    "A Bunch of Rocks"
    http://xkcd.com/505/

    Also, there are probably ways things could appear to be precise in some ways to a limited number of observers (like millions of Earth scientists), but not really being fully fleshed out. However, going down that rabbit hole involves many deep existential questions (like how can I know anything at all exists, or has existed, or will exist, how can I trust my memories, how many observers really exist, etc.) that most physicists may be better off ignoring, either career-wise or for mental health reasons. :-)
    http://disciplined-minds.com/
    "Upon publication of Disciplined Minds, the American Institute of Physics fired author Jeff Schmidt. He had been on the editorial staff of Physics Today magazine for 19 years. Following advice given in the book itself, Schmidt and free-expression advocates mounted a campaign that brought public judgment to bear on Schmidtâ(TM)s dismissal. Such justice is available to anyone not afraid to go public."

    That said, such an essay might fairly criticize specific conclusions in "the simulation argument" itself, since much of that is indeed speculative related to "ancestor simulation" or best practices for living in one. But for anyone who has spent time using computer VMs, as well as the mathematics of infinities, the essay-as-is sounds fairly limited in its thinking.

    Of course, even the notion of "infinity" has its controversies: :-)
    "Dispute over Infinity Divides Mathematicians "

    --
    A 21st century issue: the irony of technologies of abundance in the hands of those still thinking in terms of scarcity.
  46. Re:"Light drag?" by Agent0013 · · Score: 1

    Upon reading this article and thinking about the red-shift I had a new thought that I was wondering about. If the space is expanding while the light is travelling through it, what says that the red-shift is from the movement of the original object and not the movement of expanding space underneath the light. Water waves would be shifted with both a moving wave generator and a stationary wave generator in a stream. The waves upstream would be compressed while the waves downstream would be lengthened. This would lead to greater red-shifts for further objects not because they are travelling faster away from us, but because they have spent more time in expanding space. Do we know that the expansion of space does not effect a change in the frequency of EM radiation?

    --

    -- ssoorrrryy,, dduupplleexx sswwiittcchh oonn.. -Quote found on actual fortune cookie.
  47. Re:"Light drag?" by megahurts.gr · · Score: 1

    but... but... that's precisely what is supposed to be happening according to the currently accepted models: the red shift is _not_ due to the galaxies actually moving apart in space, it is due to the space itself expanding between them, in combination with the fact that the speed of light remains constant despite the expanding space.

    Now, if space is expanding, then I could hold one end of a (long enough) yardstick standing on this galaxy, and you could hold the other end standing on another galaxy, despite the red shift, because the yardstick would be expanding together with the space between the galaxies. This essentially means that there is no way to detect the expansion of space in the physical world other than by studying light. Which means that if light behaves in some way that we do not yet understand, then it could very well be that there is no expansion taking place at all.

    The tired light hypothesis says forget that awfully exotic stuff about expansion of space, there is a much simpler explanation, everything is more or less stationary, nothing is expanding, and the red shift is due to some as of yet unknown property of light which reduces its frequency as it travels through space.

    --
    This guide is definitive. Reality is frequently inacurate. (from THHGTTG)
  48. Re:"Light drag?" by Agent0013 · · Score: 1

    The tired light theory is an interesting one, and I can see how it can fit well with observations. I like the tired light because it does seem to make the expanding universe less certain. Even the Big Bang becomes questionable and I see the CMBR as a possible detection of light that has given up the last of it's energy due to traveling too far.

    I was more thinking about red-shifting accumulating due to the distance from the object. They always mention that further objects are more red-shifted due to them moving away from us faster. But if the red-shift accumulates over the distance due to more and more red-shifting coming from the expansion of space itself, then that doesn't tell us speed of the distant object, just the distance. I guess perhaps I always misunderstood what they meant by the red-shift being due to the objects traveling away from us. It's kind of a subtle difference perhaps. Does the red-shift happen at the point of departure of the object that is moving away from us due to the expansion, or does the red-shift happen during the journey from source to destination. Now that I write it out the first scenario makes little sense as different destinations would need to see different red-shifting amounts. I guess it would be: a) red-shift is due to the difference in speed, or b) red-shift is due to space stretching out underneath the light waves as the travel. Obviously the speed would have an additional effect or you could never see something blue-shifted due to it's actual motion relative to us.

    --

    -- ssoorrrryy,, dduupplleexx sswwiittcchh oonn.. -Quote found on actual fortune cookie.
  49. Re:"Light drag?" by megahurts.gr · · Score: 1

    Right, it is both (a) and (b). The dominant kind of shift observed is red, and it has minor variations due to actual movement of galaxies in space, in addition to the (supposed) expansion of space.

    The Andromeda galaxy, which is the closest one to us, and therefore not very red-shifted to begin with, does in fact move towards us in space, (we will collide at some point in the very distant future,) and for this reason it is slightly blue-shifted.

    On the wikipedia entry for "Andromeda Galaxy" http://en.wikipedia.org/wiki/A... the bar on the right hand side says "Redshift z = -0.001001 (minus sign indicates blueshift)"

    So, of course the tired light hypothesis does not deny that light undergoes a doppler effect; it just tries to explain why the red shift appears to increase as the distance increases.

    --
    This guide is definitive. Reality is frequently inacurate. (from THHGTTG)
  50. Re:Slashdot, byebye! by Jane+Q.+Public · · Score: 1

    OP says "paradox" but the issues discussed in the paper are not strictly paradoxes, just contradictions. There is a difference. If you say it's black and I say it's white, that's not a paradox but a contradiction. If one theory says it's red and another theory says it's green, again that's not paradox but mere contradiction.

    But I'm here for an argument!

    I told you once.

  51. Re:Gravity is the weakest force by Bengie · · Score: 1

    The simplest calculation tends to be the most correct. We almost always start out with something complex, and as we find out more information, we can simplify the equation. The more complex something is, the more likely it is to be "brittle".

  52. redshift by minyard · · Score: 1

    could the redshift of distant galaxies be attenuation of light?