# If the LHC test energy levels present just after the Big Bang, is it possible to test higher energies? [closed]

And, if so, would that be relevant to anything in this universe?

## closed as unclear what you're asking by AccidentalFourierTransform, Sebastian Riese, stafusa, Jon Custer, Kyle KanosJul 17 '18 at 10:05

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• The LHC is nowhere near the energies close enough to the Big Bang. No machine the humanity could even dream to build in any distant future would ever be close. The physics shortly after the Big Bang is experimentally untestable. We can only try to deduce what was happening back then based on an indirect evidence. – safesphere Jul 16 '18 at 0:55
• I don't think that the fact that the question makes a false premise (that the LHC tests energy levels close to those just after the Big Bang) justifies close votes. If the edit isn't too drastic, I would suggest a question like "Is it possibly to test collisions at energies higher than those achieved by the LHC? Would they be relevant to anything?" Those would be reasonable questions, though the answers are somewhat straightforward. Additionally, such an edit would invalidate the existing answer by Michael Seifert. (Or am I missing the intentions of the present close votes?) – user191954 Jul 16 '18 at 13:40
• @Chair the second part of the query (would they be relevant to anything) would be off-topic as too broad. – Kyle Kanos Jul 17 '18 at 10:04

I think you may have understood what is meant by "just after the big bang". According to the laws of physics as we currently understand them, the temperature in the immediate aftermath of the Big Bang was (roughly) inversely proportional to the square root of the time since the Big Bang: $T \propto t^{-1/2}$. In other words, it was about $1.3 \times 10^{10}$ K one second after the big bang; $1.3 \times 10^{11}$ Kelvin 0.01 seconds after the Big Bang; $1.3 \times 10^{12}$ Kelvin 0.0001 seconds after the Big Bang; and so forth. Extrapolating, you can find a moment some tiny fraction of a second after the Big Bang where the temperature was arbitrarily high. And the hotter the Universe was, the more energy the particles had at that time.
So when people say "the LHC is giving particles energies not seen since the moment after the Big Bang", what they really mean is something like "since $10^{-3}$ seconds after the Big Bang" or something like that. A particle collider with even more energy would be able to probe up energies that only existed $10^{-5}$ seconds after the Big Bang, and an even more powerful one would be able to probe energies $10^{-10}$ seconds after the Big Bang.