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Space Science

Past a Certain Critical Temperature, the Universe Will Be Destroyed 143

Posted by timothy from the tautologies-are-tautologies dept.
StartsWithABang writes: If you take all the kinetic motion out of a system, and have all the particles that make it up perfectly at rest, somehow even overcoming intrinsic quantum effects, you'd reach absolute zero, the theoretically lowest temperature of all. But what about the other direction? Is there a limit to how hot something can theoretically get? You might think not, that while things like molecules, atoms, protons and even matter will break down at high enough temperatures, you can always push your system hotter and hotter. But it turns out that the Universe limits what's actually possible, as any physical system will self-destruct beyond a certain point.
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Past a Certain Critical Temperature, the Universe Will Be Destroyed More

Past a Certain Critical Temperature, the Universe Will Be Destroyed

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  • This universe will self-destruct in 15... (Score:1)

    by Anonymous Coward

    ... Slashdotian time units*.

    * A Slashdotian time unit is defined as 1/15th of the time of this post to the universe's self-destruction.

    • Ah, so one Slashdotian time is the theoretical time after which a story will no longer have new dupes posted? That makes things make much more sense around here.

  • "News" for nerds (Score:1, Insightful)

    by Anonymous Coward

    So, you've got a pop-sci article about what happens at high temperature. Let's break down just a few of the failures:

    i) It talks about things that have been known for decades - not exactly news.
    ii) Talks about phenomena like eternal inflation as though they are fact, rather than quite speculative.
    iii) The summary contradicts the article itself claiming a max temp is necessarily imposed.
    iv) The article claims that if we convert all the energy in the observable universe to heat we hit a maximum, completely ig

    • Re:"News" for nerds (Score:5, Interesting)

      by erebus2161 ( 3441365 ) on Saturday June 13, 2015 @09:29PM (#49906713)
      Yeah, it's a pop-sci article about what happens at high temperature. Your tone makes this sound like a bad thing, but I'm not sure what is wrong with explaining the currently accepted best model of cosmology in accessible language. Not everyone has a background in theoretical physics and I think it's kind of awesome that some people try to bring science to more people. i) It does talk about things that have been known for decades, but it never claims to be news. And I think a lot of people forget about the second half of the Slashdot motto, "Stuff that matters." ii) I didn't see anything about eternal inflation in the article, but as far as whether they are fact or speculative, in my experience most of physics is speculative. That's why we have the Theory of Relativity, the Standard Model of Particle Physics, etc. Notice the words theory and model. iii) It doesn't. Both the summary and the article claim the Universe limits the max temp. iv) I think the article was just doing some math with what we know about the composition of the observable universe to make a point. v) I'm not sure how a maximum temperature contradicts a big bang model. Possibly because a big bang model would mean that all the matter and energy in the observable and non-observable universe were condensed to a very small volume or singularity the temp according to the article would be higher than the temp for inflation and therefore that small volume or singularity could never have been reached in the first place because inflation would have taken place earlier and caused space to expand and cool? I'm guessing at your point. I guess I just don't get the hate towards StartsWithABang. They get a lot of posts on Slashdot which I guess is suspicious, but the information always seems objectively presented, accurate and maybe some people don't like the writing style, but I think it is ok to be excited about science when you are writing for a general audience and not presenting a piece of academic research.

      • I guess I just don't get the hate towards StartsWithABang. They get a lot of posts on Slashdot which I guess is suspicious, but the information always seems objectively presented, accurate and maybe some people don't like the writing style, but I think it is ok to be excited about science when you are writing for a general audience and not presenting a piece of academic research.

        Neither i get that hate towards StartsWithABang (when it is more than a rightful criticism for the (at least) "suspicious" constant posts on Slashdot) - their articles (this was not their best in my opinion, but anyway, it was in their usual easy to understand motif) are "advanced" enough for the "general audience" (people like me, who like Cosmology but could not understand "a piece of academic research", as you put it - i could not even follow most of your points in your comments criticizing the points of

      • Re:"News" for nerds (Score:4, Interesting)

        by jfengel ( 409917 ) on Sunday June 14, 2015 @10:52AM (#49908795) Homepage Journal

        A lot of hate might be averted by making it clear that it's a review article rather than a news article. This is a news site, and its audience has a large numbers of experts and interested laymen. The assumption is that it's telling us something we don't already know, and the style of the summary is no different from any other Slashdot post. The effect sounds offensive and condescending: "Here's a thing you didn't know!" "Actually, I do, and better than the underlying article."

        The article itself is (usually) fine in its original context. It's the appearance on Slashdot that aggravates the Slashdotters. Combined with the fact that people are rather sensitive to spam, and an out-of-place article looks like spam (even if it isn't), which ties into a whole separate set of aggravations.

        If they were to present it with a different subtext: "Hey, we're nerds here. This is a topic that many of you know about, but many don't, and it would be interesting to discuss it amongst ourselves. This article is a good starting point." That would start with a different writing style, one that didn't imply that the information was brand new. It wouldn't hurt to add a visual differentiator as well: a different icon, maybe even a different color or shape. And perhaps a way for people to filter it from their streams.

        I get that there isn't nearly as much interesting, discussable news as one might think, so Slashdot has to drag in some stuff from wider afield. If they acknowledged that, and adjusted for it, they could make it a positive experience for their audience, rather than a negative one.

    • Re: (Score:1, Troll)

      by Jack Griffin ( 3459907 )
      I didn't RTFA, the headline sounded like yet another alarmist warning about climate change.

  • (And now i feel dirty for mentioning it)

  • This guy has anawful lot of confidence in how the universe works, I'll give him that much. I am only a lowly being compared to him, but isn't this all speculation? I'm pretty sure this is not a science with any kind of proof or even basic consistent knowledge, but don't let me get in the way.

    • I'm no physicist, but it sounds wrong to me: the energy he names is merely 10^24eV, which is not far beyond energies of observed cosmic rays (10^21eV-ish). It's inconceivable that this hasn't been ever reached within the Universe, which according to the guy's claims should have caused a reset.

    • Re:This guy... (Score:4, Informative)

      by Baloroth ( 2370816 ) on Saturday June 13, 2015 @09:17PM (#49906669)

      This guy has anawful lot of confidence in how the universe works, I'll give him that much. I am only a lowly being compared to him, but isn't this all speculation? I'm pretty sure this is not a science with any kind of proof or even basic consistent knowledge, but don't let me get in the way.

      You are correct, it's mostly a bunch of pop-sci woo-woo. For example, a massless particle no matter how energetic cannot on it's own convert into a black hole as he claims, because no matter how much energy it has you can always Lorentz boost into a frame where it has arbitrarily small amounts of energy. Likewise the photons in your room have arbitrarily large amounts of energy, depending on the reference frame you choose. But they have no mass, and a system requires a certain amount of mass to convert into a black hole (and the mass of system is invariant, i.e. it's the same in every reference frame).

      The "the Universe would be destroyed" bit is also completely and purely theoretical at this point: we have no real proof for inflation at all. Our physics just doesn't really extend to those energy scales yet.

      • Re: (Score:1)

        by Anonymous Coward

        Not invariant mass appears in Einstein equation but the stress-energy tensor. So yes, massless particles can collapse into a black hole. (if general relativity is correct at that scale)

      • Once an event horizon forms, it doesn't matter what mass/energy formed a black hole; an all-energy black hole is called a kugelblitz. No matter how much you accelerate it, though, a particle remains the same mass in its own frame. It just appears to have a higher energy to the initial frame. It's kind of like the question of an object being so fast relativity shortens it to a black hole density.

        • Yes, but a Kugelblitz requires two or more massless particles to interact to form a black hole (because while a photon is massless and can never form a black hole, a system of photons is generally not and certainly could given the right conditions). And a heat-formed kugelblitz would generally not be stable: black holes radiate energy same as any black body (in fact, black holes are basically perfect black bodies), and dissipate at a rate inversely proportional to their mass, which means at around the black

      • Re: (Score:2)

        by bidule ( 173941 )

        But they have no mass, and a system requires a certain amount of mass to convert into a black hole (and the mass of system is invariant, i.e. it's the same in every reference frame).

        Kugelblitz.

      • Re: (Score:2, Informative)

        by Anonymous Coward

        It's an Ask Ethan page. Not exactly an Explain-like-I'm-Five but plenty of pop-sci woo-woo to keep it entertaining. And that awful page layout used by every Physics web blog since 2014.

        For example, a massless particle no matter how energetic cannot on it's own convert into a black hole as he claims, because no matter how much energy it has you can always Lorentz boost into a frame where it has arbitrarily small amounts of energy

        "Mass"-less black-holes are perfectly possible. They are called Kugelbitz [wikipedia.org] and

      • Energy and mass are equivelent. Massless particles (light) can have effects like particles with mass because of their energy.

        Example: radiometers

        Don't pretend you know everything about high energy physics either.

        • Example: radiometers

          Are you referring to the Cookes radiometer? If so, it's a heat engine and requires low pressure gas in the bulb, not a hard vacuum.

      • If I recall correctly, heat is nothing more than the vibration (kinetic energy) of particles. A vibration is essentially a wave and the shortest wavelength corresponds to one of the planck limits. That means there is a maximum amount of heat that a particle can have. That also means there is a maximum frequency for electromagnetic waves.

        I have not seen the actual calculations and I do not have the requisite knowledge to perform them myself. If I looked carefully, I am sure I could come within an order of ma

  • Old topic (Score:5, Informative)

    by Dutch Owl ( 1230220 ) on Saturday June 13, 2015 @07:47PM (#49906361)
    Isaac Asimov posted a column in 1957 asking the same question. The column was subsequently published in a book of his collected scientific columns. A graduate student took the question posed by the column and used it for his doctorate thesis over fifty years ago.

  • yeah ummm (Score:1)

    by Anonymous Coward

    pics or it didn't happen.

    And wtf is with all the reposting from medium.com. /. didn't use to carry blogs.

  • just won't go away, will it?
  • There's nothing wrong with the idea that inflation might kick-off between 10^28 and 10^29 that we know about, but for any region of spacetime large enough for that to be an issue, the region should become enclosed by an event horizon. In other words, every black hole may contain its own reality. Which comports nicely with the idea that our universe is almost precisely at the critical density. Secondly, I find it much more interesting to wonder what happens when large enough regions of the universe have low

    • Re: (Score:1)

      by Anonymous Coward

      There's nothing wrong with the idea that inflation might kick-off between 10^28 and 10^29 that we know about, but for any region of spacetime large enough for that to be an issue, the region should become enclosed by an event horizon. In other words, every black hole may contain its own reality.

      Take the mass of the universe, and you'll find that the radius of the black hole is larger than observable universe. So, either we are in a black hole, or there is more to gravity.

      • Re: (Score:2)

        by Livius ( 318358 )

        either we are in a black hole, or there is more to gravity.

        Or both.

        Or what we know about both black holes and gravity is wrong.

    • Re: (Score:1)

      by Anonymous Coward

      "Secondly, I find it much more interesting to wonder what happens when large enough regions of the universe have low enough energies. Will there be another phase transition?"

      How do you know it hasn't already happened? Typical transition temperatures for Bose-Einstein condensation are on the order of 5K or so. The universe passed through 5K at a redshift of around 0.75 (which happens to roughly correspond with the redshift at which universal acceleration seems to have kicked in). It's not outwith the bounds

  • We're discussing explosives theory here, kids... get the Ammonia Nitrate bottle ready after you learn that formula, otherwise all you'll think about is how much heat it takes to make things go away..

    If you do heat the universe up to the point it all explodes, the thing giving the heat will be cold enough to survive.

    • If you do heat the universe up to the point it all explodes, the thing giving the heat will be cold enough to survive.

      I'm thinking that there is a joke about Andrea Rossi and cold fusion in there, but I can't figure it out now . . .

      "Hey, Herr Rossi sucht sein Glück - - - "

  • .... nuff said.

  • Alien version of M.A.D. Just hope suicidal terrorists don't get a hold of it.

  • Temperature is dependant on the speed of molecules. If molecules are moving at the speed of light, then the temperature can not get any higher?

    • Re: (Score:2)

      by suutar ( 1860506 )

      Temperature's not dependent on the speed, it's dependent on the energy. Below lightspeed, yes, adding energy shows up mostly as increased speed, but (according to the article) once you get past a certain energy level it stops being "massy" and instead of the speed varying with energy, it just goes at lightspeed. The effect of adding more energy would show up as something analogous to increasing the frequency of a regular photon.

    • Molecules do not travel at the speed of light; only massless particles do. It would take infinite energy to have something with positive mass going at c. Depending on the energy you put in it, you can get arbitrarily close to the speed of light.

      So, the question is, with available energy, how fast can you get something to go?

  • random fluctuations in matter will ensure that the universe will never end...and since I am a cryonicist, that means I will be immortal..while you will be eaten by the worm....

  • FTFA:

    If you managed to reach temperatures sufficient to bring this field back into its inflating state, you would effectively hit the “reset” button on the Universe, and cause inflation to resume, resulting in the Big Bang starting all over again.

    Would such a temperature have to be above or below the Planck temperature? If an object were to reach the temperature of 1.41 x 10^32 Kelvin, the radiation it would emit would have a wavelength of 1.616 x 10^26 nanometers (Planck length). Beyond that, i

    • AFAICT, there is no known physical effect of Planck units. Heck, the Planck mass is very approximately twenty micrograms, and nothing seems much changed above or below that.

  • I've read/scanned one of his articles, that won't happen again. He was saying the Universe has always existed and always will (Steady State theory) and proving it, under the guise of what if.

  • I feel so limited. I hate this Universe!
  • Pyromaniacs, like other dedicated individuals, need goals.

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