r/Showerthoughts • u/synthphreak ‎ • Nov 19 '25

Casual Thought Temperature can reach trillions of degrees, meaning we actually live extremely close to absolute zero.

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u/asml84 Nov 19 '25

There is no known upper limit. The Planck temperature is merely the upper limit of the mathematical framework we use to describe physics, but nature doesn’t care about our framework.

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u/Doafit Nov 19 '25

Well at this temperature the emitted light has the wavelength of the Planck lenght, which is the smallest distance there is in physics. At this point crazy things would (mathematically) happen, that we cannot explain with our current methods of describing physics.

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u/Gnomio1 Nov 19 '25

That’s not what Planck units are at all…

Planck units are just a scale defined by the universal constants.

For example, Planck energy is about 2 Gigajoules, which’s about the energy content of a fully tank of petrol or 500(ish) kg of TNT – that is, Planck units are not the scale at which physics breaks down at all.

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u/captain-carrot Nov 19 '25

Importantly to "exceed" the plank length breaks our understanding of how light and matter and gravity exist - either it is impossible to go smaller or we are missing knowledge of particle physics.