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Space Science

Is There Such a Thing As Absolute Hot? 388

Posted by timothy
from the she-does-exist-yes dept.
AlpineR writes "Is there an opposite to absolute zero? An article from PBS's NOVA online explains several theories of the maximum possible temperature. Maybe it's the Planck temperature, 10^32 K, beyond which the known laws of physics break down. Or maybe just 10^30 K, the limit of some versions of string theory. If space is actually 11-dimensional then the maximum temperature could even be as low as 10^17 K, attainable by the Large Hadron Collider. Or maybe infinite temperature wraps around to negative temperature and absolute hot is the same as absolute cold."
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Is There Such a Thing As Absolute Hot?

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  • by m50d (797211) on Monday December 24, 2007 @11:52AM (#21806158) Homepage Journal
    That's what you get for writing a universe in C.
    • by Anonymous Coward
      Black holes are garbage collection.
    • by The MAZZTer (911996) <<megazzt> <at> <gmail.com>> on Monday December 24, 2007 @12:27PM (#21806608) Homepage
      I always thought it was written in lisp [url=http://xkcd.com/224/]until I learned otherwise[/url].
    • God Wrote in Lisp (Score:4, Interesting)

      by naoursla (99850) on Monday December 24, 2007 @03:01PM (#21808294) Homepage Journal
      http://www.gnu.org/fun/jokes/eternal-flame.html [gnu.org]

      I was taught assembler
      in my second year of school.
      It's kinda like construction work --
      with a toothpick for a tool.
      So when I made my senior year,
      I threw my code away,
      And learned the way to program
      that I still prefer today.

      Now, some folks on the Internet
      put their faith in C++.
      They swear that it's so powerful,
      it's what God used for us.
      And maybe it lets mortals dredge
      their objects from the C.
      But I think that explains
      why only God can make a tree.

      For God wrote in Lisp code
      When he filled the leaves with green.
      The fractal flowers and recursive roots:
      The most lovely hack I've seen.
      And when I ponder snowflakes,
      never finding two the same,
      I know God likes a language
      with its own four-letter name.

      Now, I've used a SUN under Unix,
      so I've seen what C can hold.
      I've surfed for Perls, found what Fortran's for,
      Got that Java stuff down cold.
      Though the chance that I'd write COBOL code
      is a SNOBOL's chance in Hell.
      And I basically hate hieroglyphs,
      so I won't use APL.

      Now, God must know all these languages,
      and a few I haven't named.
      But the Lord made sure, when each sparrow falls,
      that its flesh will be reclaimed.
      And the Lord could not count grains of sand
      with a 32-bit word.
      Who knows where we would go to
      if Lisp weren't what he preferred?

      And God wrote in Lisp code
      Every creature great and small.
      Don't search the disk drive for man.c,
      When the listing's on the wall.
      And when I watch the lightning burn
      Unbelievers to a crisp,
      I know God had six days to work,
      So he wrote it all in Lisp.

      Yes, God had a deadline.
      So he wrote it all in Lisp.

    • by Xzzy (111297) <sether@tru7[ ]rg ['h.o' in gap]> on Monday December 24, 2007 @03:29PM (#21808544) Homepage
      It's a sound argument for intelligent design. If temperature overflows, it means we were all programmed and god does, in fact, exist.

      The downside is he's a first year CS student.

      It would certainly explain a lot. The universe's expansion is just a memory leak and the big bang was simply POST. Black holes? Core dumps. I just worry what happens when he wedges the machine and has to reboot.
  • Could be... (Score:5, Insightful)

    by Meshach (578918) on Monday December 24, 2007 @11:53AM (#21806166)
    I would have never thought there was a speed limit for the universe before I read Einstein's special theory of relativity. Anything is possible.
    • Re: (Score:3, Funny)

      by sm62704 (957197)
      I would have never thought there was a speed limit for the universe before I read Einstein's special theory of relativity.

      Which should not be confused with Einstien's "special" theory of relativity, which states that no matter who you are, all your relatives seem like retards.

      -mcgrew

      (Einstien would never be confused with Einstein, would he? Except maybe by one of your relatives...)
  • Sure (Score:4, Funny)

    by Anonymous Coward on Monday December 24, 2007 @11:53AM (#21806168)
    > "Or maybe infinite temperature wraps around to negative temperature and absolute hot is the same as absolute cold."

    Or maybe the universe is a snake eating its own tail!

    Or maybe monkeys will fly out of my butt.
    • Re:Sure (Score:5, Funny)

      by WombatDeath (681651) on Monday December 24, 2007 @12:03PM (#21806302)
      I think you've hit on something with the snake idea.

      Anyway, it's a little-known fact that 'absolute hot' is 39.6 degrees celsius (about 103.3 degrees fahrenheit). Any observation indicating a higher temperature is simply due to malfunctioning apparatus or experimental error.
    • by Smidge204 (605297)
      No way.

      Clearly, it's turtles all the way down.
      =Smidge=
  • by Anonymous Coward on Monday December 24, 2007 @11:54AM (#21806174)
    Yes, and it's my wife's sister. I love the holidays!
  • But the answer is much, much simpler.

    42.
  • by Anonymous Coward on Monday December 24, 2007 @11:58AM (#21806234)
    McDonald's coffee?
  • by Malevolent Tester (1201209) on Monday December 24, 2007 @11:58AM (#21806238) Journal
    Margaret Thatcher. Covered in whipped cream. (apologies to anyone who was planning to close their eyes in the near future)
    • Your sig (Score:3, Funny)

      by sm62704 (957197)
      Margaret Thatcher. Covered in whipped cream

      The developers aren't the only ones you've made cry today. How do I get that horrible picture out of my tortured barin? You fiend! Did you learn that awful technique in your CIA "special rendition" class?
  • by BlueParrot (965239) on Monday December 24, 2007 @12:02PM (#21806284)
    I have to wonder about the definition of temperature at such high energies. I would think it would be difficult to envisage a situation where you have anything resembling a Maxwell-Boltsman distribution at 10^33 K, so just what is meant with temperature in this case?
    • Re: (Score:3, Informative)

      Maxwell-Boltzman probably wouldn't apply anyways, because at >10^32 K it would be pretty hard to be in thermal equilibrium. As for your question... maybe I just don't understand the physics enough, but wouldn't temperature still be defined as the average of atomic vibration, in this case the very large atomic vibrations.
      • by Yvanhoe (564877)
        But where are the atoms at this... energy density ?
      • by Tmack (593755)

        ... wouldn't temperature still be defined as the average of atomic vibration, in this case the very large atomic vibrations.

        My guess would be that absolute hot is when the vibrations reach a point where either the vibrations shake the atoms and protons/neutrons/electrons and maybe even quarks apart (inertial forces greater than the internal forces of the particles/quarks/whatever), or they stop vibrating because the vibrations turned into pure linear motion in the same vector by all particles simultaneously at a velocity of c resulting in infinite volume, much like absolute zero is the lack of vibration, and thus lack of volu

        • by digitrev (989335)
          Interesting theory, but you neglect the issue of acceleration. Using your theory, I think it would be the limit as velocity of vibrations approaches c, and the time between maxima and minima of vibrations (think left and right edges in a two-dimensional simplification) is non-zero, but approaching zero. I'm not sure how well this would work, as it would require a minimum unit of delta t for an "absolute hot" to exist.
    • by fermion (181285) on Monday December 24, 2007 @01:02PM (#21807034) Homepage Journal
      Most of us have difficulty differentiating heat and temperature [uh.edu]. I am not even going to try to come up with a simple definition here. But, as the referred transcript states, if you have a very thin gas, temperature does, in some way, relate directly to motion. Therefore, absolute zero is approximately defined as the point where the atom in gas, where the atoms do not hit each other often, would stop moving. At present, I know of now peer review paper reporting 0 K reached, though some groups have come very close.

      So the question of maximum temperature is not so silly. There are a number of ways to approach it from various definitions. If we have a few atoms in a large space, then perhaps we can drive those atoms to the speed of light, but no further. If we think of it thermodynamically, as Dr. Lienhard suggests, then we can ask is there an limit to the heat that can be driven between two systems. Such a limit would suggest a maximum temperature if we assume newtons law of cooling, which is itself is approximate, can be applied a large temperature differences, which it probably cannot.

      In any case, nature, at least we way that science approaches it, appears to abhor vacuums [marinelayer.com] and black holes, both of which seem to exist, but don't seem to make sense. The question is apt as we have seem that assuming infinities do us little good.

    • Re: (Score:3, Informative)

      I have to wonder about the definition of temperature at such high energies. I would think it would be difficult to envisage a situation where you have anything resembling a Maxwell-Boltsman distribution at 10^33 K, so just what is meant with temperature in this case?

      If you're referring to exp(-B/kT), then the high temperature will swamp the B (activation energy), meaning that all states will be effectively uniformly populated. So at infinity, I believe a Botzmann distribution ends up as pretty much a unif

  • by bchernicoff (788760) on Monday December 24, 2007 @12:03PM (#21806312)
    DUH!
  • by Fieryphoenix (1161565) on Monday December 24, 2007 @12:03PM (#21806314)
    While it may well be that there is a maximum "energy density" for a particular space, it would not really be a true opposite to absolute zero. Absolute zero represents complete cessation of motion... a true opposite would be infinite motion (obviously not infinite velocity). Also, it seems quite possible that whatever upper limit exists at one particular time in one particular space may differ from another... either varying as the universe ages, with whatever gravitational field may exist locally, or at the very least in different universes that may exist. As such, while absolute zero is just that... absolute (in that no heat is no heat under all conceivable reference points), "absolute heat" almost certainly does not uniformly exist. I suppose another way to say is that if you plug absolute zero in as the value in a mathematical calculation, you will always get the same result, but there is no one value "absolute heat" corresponding, which can closely approach actually existing in our universe.
    • Re: (Score:2, Interesting)

      by Kwiik (655591)
      Your logic is flawed

      If the question was to ask for the opposite of "cessation of motion", you may be right

      However, asking for the opposite of absolute zero is not asking for the opposite of the results of absolute zero. The defining attribute is that absolute zero is the lowest amount of heat possible, therefore to reverse this we are looking for the "opposite of lowest" amount of heat possible, or the lowest amount of "opposite of heat" possible, both are the same thing, and that's what this article is ta
      • by sumdumass (711423)
        Is it too difficult to envision something where there is a saturation rate as far as heat is concerned and an absolute temperature would be the boundary between the ability to store energy (in heat) and where something becomes energy in itself.

        I have nothing to back that up but heat is basically a form of energy, given the atomic makeup of everything, could heat turn something into pure energy or more aptly, break down the atomic structure to a point that we see it as pure energy. therefore, at an absolute
    • by teslar (706653)

      As such, while absolute zero is just that... absolute (in that no heat is no heat under all conceivable reference points), "absolute heat" almost certainly does not uniformly exist
      Yeah, agreed, but this is just semantics. It'd be more correct I think to talk of the 'highest possible' temperature as opposed to the "absolute" hot. And I see no reason why that should not exist - no infinity in this Universe ;)
    • Re: (Score:2, Interesting)

      by jbengt (874751)

      Absolute zero represents complete cessation of motion

      No, absolute zero represents the minimum energy state possible for the system being considered. For an ideal gas that would be a complete cessation of motion but not so for a real system.

      Presumably, the highest temperature possible would represent the maximum energy state possible for the system being considered. What that might be is unknown, especially unknown to me, but presumably would not have to be infinite.

      A nitpick, heat is not measured

  • Speed (Score:3, Interesting)

    by Chairboy (88841) on Monday December 24, 2007 @12:07PM (#21806362) Homepage
    Absolute zero is when all atomic motion ceases, right? The effective speed limit of the universe is the speed of light, so I'd assume absolute hot would be when when the atoms are traveling near or at the speed of light. Because mass cannot actually reach the speed of light, nothing can actually reach the absolute hot.

    Or is that super mega crazy talk?
    • Re:Speed (Score:5, Informative)

      by Cyberax (705495) on Monday December 24, 2007 @12:11PM (#21806432)
      Nope.

      Temperature depends on particles _energy_. At low temperature particle energy is calculated as E=m*v^2/2, but if you start to get closer to the light speed then the _MASS_ of a particle will grow. So you can get arbitrarily large energy as you approach the "c" limit.
    • by jdray (645332)
      For my layman's knowledge of physics, that's the best answer I've read yet.
    • Re:Speed (Score:5, Informative)

      by BlueParrot (965239) on Monday December 24, 2007 @12:20PM (#21806510)
      Temperature is defined in terms of the energy, not speed. At high velocities the mass of particles grow with their speed as per Einstein's theory, so even thou the top speed is limited, energy is in fact not. As a particle's speed aproaches the speed of light its energy diverges. This is in fact WHY you can't accelerate particles to the speed of light. As you get closer to C the particle mass starts growing rapidly so larger and larger amounts of energy is needed for smaller and smaller increments in speed. Thus you can't accelerate a particle to C using only a finite amount of energy. This effectively means that realitivity doesn't limit temperature. There may of course be other limits involved.
      • by Colin Smith (2679)

        Thus you can't accelerate a particle to C using only a finite amount of energy
        And there is an infinite amount of energy in the universe?
         
    • Is it the speed that the particles travel that dictates their temperature or the rate at which the paricles vibrate?

      I remember that you can increase the temperature of a gas by increasing the pressure on it. It's sort of like if you take one of those super bouncy balls and drop it straight down and let it bounce up and down a while. If you slowly lower your hand on top of the ball so that it bounces off of your hand to the floor, the ball will bounce faster and faster as your hand goes down. Even though
    • This is probably redundant but Ihaven't read all the way down.
      Temperature is a measure (the logarithm of, in fact) of the number of available energy states that the particles in question can populate. Absolute zero simply means the ensemble has only one available energy state. This in no way means there is zero energy or zero motion. Atoms will still exist at absolute zero -- unless there's some newfangle theory I missed that claims cold electrons will just fall from their P-zero orbitals.
  • by Anonymous Coward on Monday December 24, 2007 @12:08PM (#21806382)
    "Is there such a thing as absolute hot?"
    1. Turn on a burner on the stove. Turn it up as high as it will go.
    2. Wait 5 minutes for the burner to warm up.
    3. Place the palm of your hand on the burner.
    4. You tell me.
  • by foxtrot (14140) on Monday December 24, 2007 @12:11PM (#21806422)
    Seems to me there would have to be an absolute hot. Absolute zero, ferinstance, is the temperature at which all molecular motion stops. Nothing moves at absolute zero. Heat would, then, be a function of how fast the molecules are moving in a given substance, right?

    Given that the universe has an effective speed limit ( C: it's not just a good idea, it's the law), it seems to me that for a given substance, there has to be an upper limit of how hot it can get solely because the molecules within it aren't allowed to vibrate any faster. (I'm not certain that the function of vibration speed to heat isn't substance dependent-- it may be.)

    However, given that the idea of an absolute hot is apparently not agreed upon by physicists, I am probably missing something important in my layman's analysis of the situation.

    -F
    • by KefabiMe (730997) <garth@NOSpaM.jhonor.com> on Monday December 24, 2007 @12:26PM (#21806594) Journal

      What happens when we add energy to the speed of a particle? When the speed gets closer and closer to the speed of light, the mass starts increasing.

      Here's the important part that you probably already know. When an object nears the speed of light, the mass starts increasing. We can't cross the speed of light because more and more energy is required to accelerate the object.

      Note that we can keep putting (unlimited amounts of) energy into the object and it will never go faster than light.

      My theory? When so much energy is put into such a small space, it hits a form where the energy resonates and becomes primarily matter without any energy left over for movement. (Sound familiar? Absolute Hot and Absolute Cold are the same thing?) Matter, acceleration, velocity, temperature, energy... it's all the same thing just in different forms. =)

    • Temperature is not a measure of the average speed of the particles in a system, but rather their average translational kinetic energy, which is a function of their speed when relativistic effects are not taken into account. However, there is no limit to the kinetic energy as speed increases towards c, and thus no limit to temperature. The story is a bit more complicated, but this is the first thing you overlooked.
    • Heat would, then, be a function of how fast the molecules are moving in a given substance, right?
      Temperature, not heat. Heat is no state function [wikipedia.org]
    • by jbengt (874751)
      "Absolute zero, ferinstance, is the temperature at which all molecular motion stops. Nothing moves at absolute zero"

      Absolute zero is the minimum energy state allowable, there may be some motion required by quantum mechanics even at the minimum energy state of absolute zero.
  • The opening sentence of the article kind of ruined it for me as a science article because of the use of such a ridiculously archaic unit. I can understand the stubbornly conservative US population rejecting these new-fangled SI units, but I would've thought the scientific community, and the scientific media, would have more sense. Didn't you guys trash a Mars probe because of some idiot using PSI when he should've been using Pascals?
    • Re: (Score:3, Insightful)

      by KokorHekkus (986906)
      You do know that NOVA is a popular science program? Popular as in intended for the the general public. It's not a science article just meant for people with a decent scientific background. In this case I think it's perfectly ok to include temperature in F and they even started with Kelvin first. Yeah, it might have ruined it for you (seriously, you might want to tune down your sensitivity a bit) but it also made it a lot more accessible to the general public.
      • by damburger (981828)

        The purpose of a popular science programme is surely to educate - and thus they should be encouraging Americans to us the same (sensible) units the rest of the world does. Clinging onto ancient and arbitrary units (yes, I know Celsius is arbitrary too, but its less arbitrary because the degree increments fit in with all the other SI units) makes it harder to collaborate with the rest of the civilised world. It just seems like juvenile bloody mindedness.

        In any case, your right to call British people and th

        • by chill (34294)
          In any case, your right to call British people and things 'quaint' is suspended until such a time as you stop measuring temperature in Fahrenheit.

          Sure, right after you people stop measuring weight in "stone". And why does the BBC Weather give temperature measurement in both C and F? And don't you people still use "miles" for a distance measure?

          Pot, meet kettle.
          • by damburger (981828)
            1. Stones is one of the few imperial measurements that have hung on, but its on the way out. I and many my age know my weight in kilograms but not in stones. 2. BBC Weather doesn't give the temperature in Fahrenheit (unless it does so when you connect from an American IP) OK, some imperial measurements survive in Britain but they are on the way out. Miles are used on road signs (probably because of the cost of a changeover, although I imagine it is coming) but speedometers have both mph and km/h on them.
            • by chill (34294)
              Thanks.

              Just for comparison, in the U.S.:

              1. Soda (coke, pepsi, etc.), when sold in bottles, is usually 2 liters. Wine and hard liquor is almost always sold in ml (750 ml being the most common). Beer and canned soda is usually in fluid ounces, but ml is printed on the label.

              2. All cars have had speedometers in both Mph and Kph for 30 or so years now. We once had a push to have road signs in both, but now only a few States do that. Most have given up.

              3. Most things that are purchased by weight have both po
              • Too true..

                Soda is sold by the 2 liter bottles, yet milk is sold by the gallon. However, 3,8 l is also on there....

                And where I work at (starbucks) 3.8 measures out to 4 l from most of our milk producers. Our cream based frappucinos require milk for preparation, we make 4 liters at a time. One gallon should be .2 l shy, but almost never is.

                And btw, all of our ingredients and preparatory instructions are in metric.
        • In any case, your right to call British people and things 'quaint' is suspended until such a time as you stop measuring temperature in Fahrenheit
          I have never called British 'quaint' and I've used SI units my whole life... because I'm Swedish (see http://slashdot.org/comments.pl?sid=361649&cid=21364841 [slashdot.org] for example). To this me is just flamebait.
  • by gr8dude (832945) on Monday December 24, 2007 @12:15PM (#21806466) Homepage

    Is there a corresponding maximum possible temperature? Well, the answer, depending on which theoretical physicist you ask, is yes, no, or maybe.
    This sounds... incredibly familiar!
  • Spoiled It (Score:3, Insightful)

    by RAMMS+EIN (578166) on Monday December 24, 2007 @12:18PM (#21806494) Homepage Journal
    I found the line of thought intriguing, until it said "negative temperature". The whole point of "absolute zero" is that there _are_ no negative temperatures.
  • Or maybe (Score:5, Funny)

    by roman_mir (125474) on Monday December 24, 2007 @12:18PM (#21806496) Homepage Journal
    we should switch the scale of hotness: accept Carmen Electra as 1 unit of hotness as measured in the year 2000. Also accept that 2 Carmen Electras is twice as hot as 1 Carmen Electra. As the number of Carmen Electras approaches infinity, their total combined hotness approaches some saturation limit, after which it is no longer possible to determine whether hotness of N x Carmen Electra is greater than hotness of (N+1) x Carmen Electra, which breaks down the laws of mathematics and thus the laws of physics by making N=N+1.

    I must add that Chuck Norris can kick Carmen Electra's ass even at the hotness limit.
  • by sbaker (47485) * on Monday December 24, 2007 @12:22PM (#21806538) Homepage
    Temperature is basically the average kinetic energy of the particles, and kinetic energy is half the mass times velocity squared, when things start to get very hot, the particles would eventually start getting up to relativistic speeds.

    This has lead some people to suggest that the cosmic speed limit (the speed of light) imposes a cosmic temperature limit - but that's NOT the case.

    As things start to move closer and closer to the speed of light, relativity says that their mass increases (as seen from the perspective of an outside observer). Whilst there is a cosmic speed limit - as you approach it, your mass increases without limit. Since unlimited mass and finite velocity means unlimited kinetic energy, relativity does not impose a cosmic temperature limit.

    If there is a cosmic temperature limit, it's caused by something else.
    • by jd (1658)
      I'm half asleep right now, but are you certain you're not mixing up heat and temperature? The two are not the same, and I could easily see heat increasing without limit but temperature increasing relativistically to a finite value.
  • That would absolutely bend my brain - a thermal equivalent of a Smith Chart. [wikipedia.org]
  • Obviously the poster hasn't seen Monica Bellucci in Malèna!
  • Is There Such a Thing As Absolute Hot?

    Umm... Heidi Klum?

  • I think calculation of the Hagedorn temperature at 10^30 K should be taken with a massive grain of salt. String theory has an adjustable parameter, which is the length scale on which the extra dimensions are curled up. Since string theory is supposed to be a model of quantum gravity, and there is only one fundamental length scale in quantum gravity -- the Planck scale -- the general assumption is that if string theory is right, that length scale should be the Planck scale. Converting that length to a tempe

  • It's clear who learned to spell from TV.
  • Taggers (Score:2, Funny)

    by Ophion (58479)
    An Infiniti is a car, and it will wrap around almost anything into which the driver rams it.
  • At the big bang (so far as we know) all of the energy (=mass) was concentrated in the same place at the same time. To be any hotter than that would require more energy than exists in the universe.
    • by ceoyoyo (59147)
      Actually in string theory there is no primordial singularity -- the universe bounces when it gets down to a radius that is equal to the Planck length. In general relativity such extreme conditions don't make sense.
  • Just an ignorant question from somebody who hasn't opened his physics-books in a while:
    If absolute zero is when particles stop their brownian motion, what is the reference-frame of that measurement? If 'd measure the motion and energy of an atom in a lab here on earth, and get it to 'stop' relative to my instruments, i'd be measureing absolute zero, right? But couldn;t earth's motion through the universe be interpreted as a 'unilateral brownian motion', which would mean that the atom actually does have at
  • Even if positive infinity wraps around negative infinity (most mathematicians don't agree but there is a minority that thinks that way), this doesn't mean absolute hot means absolute cold, because absolute cold is zero, not negative infinity.
  • This reminds me of a question posed in Middle School during our discussion of absolute cold.

    So... is there an absolute... toasty?

    Ah, the sound of 30 7th graders sputtering with laughter.

    Mmm... toasty.

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