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ArcticMyst Security by Avery

Highest possible temperature

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Apr 28, 2009
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Is there a possibility that physicists know what the highest possible temperature is? The lowest is 0 degrees Kelvin and that isn't disputed. Some physicists estimate it at 10 to the 32nd power degrees Kelvin. Also known as the "Planck temperature", which occurred at the first instances of the big bang. This temperature could never be achieved in a lab, so it will always be in the realm of theoretical physics. It would be impossible to shield scientists in a lab from a "big bang" radiation, even if they could build the imaginary reactor.
Is it possible to achieve the Planck temperature in a lab? - sci.physics | Google Groups
 





horhay

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Apr 8, 2010
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isn't that when the vibrating molecules that are indicative of heat reach the speed of light?

im curious about this too. LETS DO SOME MATH!!! and lets do it with lasers. i choose a crazily overdriven 445nm :) at a PERFECTLY focused point, the wavelength of a light wave would be the minimum diameter of the point. 445nm is the wavelength, so pi(445^2)/4= the area = 155528nm=0.155528mm(more manageable). now, for realism's sake, say this is a cube that is .15*.15*.05mm cube made in some laboratory. and lets make it out of gold, which has a fairly good specific heat for this. (assume its coated with something nonreflective.) gold is 19.3g/cubic centimeter. this peice of gold would be 0.000001125 cubic centimeters, and therefore 0.000022g. thank god for rounding. the specific heat of gold is .128J/g degree K. therefore, the energy required for one degree is 2.8*10^-6 joules. now, let's say we start at 300K, around room temperature. honestly, 300 is not a big number when talking about 10^32. so go away 300. anyway, the joules times the degrees would get us approx. how many joules it would take to raise it to that temperature. this brings us to 2.8*10^26 joules. 1 watt=1 joule/sec. so... even if we took a whole year of direct laser shining, 60*60*24*365=3.2*10^7 seconds, it would still take a 8.8*10^18 watt laser. thats a 8800000000000000000 watt laser on a tiny speck of gold for a whole year... and with error, its impossible. plus pure gold can slightly melt in a person's hands. even if my math is flawed (which it probably is) thats a lotttttt.

EDIT: dtr? you up for seeing if we can push these a bit further? :D
 
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Aug 15, 2009
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isn't that when the vibrating molecules that are indicative of heat reach the speed of light?
No, at a certain temperature you only have a plasma left, no molecules. What defines the temperature when only elementary (as far as we know) particles are left?
 

Benm

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No, at a certain temperature you only have a plasma left, no molecules. What defines the temperature when only elementary (as far as we know) particles are left?

Their speed/mass ratios. For the definition of temperature, only the mean speed of particles and their mass is important. The nature of the particles is not a factor there. If you had matter so hot it would only consist of quarks, you could still determine its temperature as long as you know the mass of these quarks and their average velocities, as well as the pressure level in whatever contains them.

As far as real life systems go, there isn't much known about the state of the universe before composite parcticles like protons and neutrons were formed. The problem is mainly in realizing such states in a lab environmnent for further study.
 
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The problem isn't coming up with the energy, the problem is containing it. Not only will the material ultimately vaporize, but it will emit radiation (blackbody or otherwise) to cool itself. That's why even an insulated light bulb with a constant 60 watts of energy pumped into it doesn't keep increasing in temperature forever. At a point, all the energy you're putting into the substance is leaking out one way or another.
 
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This problem is illustrated by the LHC, they need a 27km ring full of superconducting magnets to keep the particles in their path.
 




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