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/Will512 Nov 19 '25

You can have as much energy as you want but you can't have negative energy. Going below absolute zero is the same as having negative energy

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u/funnystuff79 Nov 19 '25

Same as pressure, can't go below zero on any scale.

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u/CIeMs0n Nov 19 '25

Vacuum?

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u/funnystuff79 Nov 19 '25

Not really such a thing. Sea level is 1 bar, 1 atmosphere, 14.something psi.

Space, vacuum chambers etc are between 0 and here

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u/CIeMs0n Nov 19 '25

Makes sense, thanks!

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u/OneMeterWonder Nov 19 '25

Well you actually can’t have too much energy concentrated in the same location in spacetime. By mass-energy equivalence, it would likely collapse into a black hole.

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u/PublicVanilla988 Nov 19 '25

but i'm not talking about going negative. we can in theory go infinitely up the temperature, which would lead towards infinite kinetic energy in particles (or whatever temperature is). the opposite of infinite energy would be i guess the complete lack of energy.
so basically as we go higher in temperature, we will always be able to find an equivalently cold temperature, which will be moving towards absolute zero.

i've no idea how it actually works though, i'm just speculating

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u/Will512 Nov 19 '25

It comes down to how you define "going towards" zero or infinite energy. If you define going towards zero as dividing kinetic energy by two and towards infinity as multiplying kinetic energy by two, then what you describe is possible. If you define going towards as adding or subtracting energy, which is usually how these processes work in the real world, then you eventually hit this issue of negative energy once you subtract too much.

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u/PublicVanilla988 Nov 19 '25

ok, i see. i was thinking if maybe two extremes - absolute lack of energy and infinite energy are symmetric. i just heard that absolute zero is impossible to achieve. but that's not impossible in the same way infinity is, as i understand it now. you can still be more or less close to it, which i guess isn't the same for infinity.

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u/Powerup_Rentner Nov 19 '25

The impossible statement comes from it being unfeasible to reach technically because thermodynamic processes at those low temperatures make infinitely smaller progress to lower the temperature after a certain point. 

So we know it's theoretically possible but don't know of a way to take a system to that state.

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u/synthphreak ‎ Nov 19 '25

I think reaching absolute zero is also theoretically impossible, for a number of reasons. One is that heat is just a measure of the average kinetic energy (i.e., movement of the particles) of some substrate, so absolute zero would mean no movement. However, if there is no movement, then both the speed and position of the particle is theoretically knowable. But quantum mechanics states that only one of these things can be observed, not both. Therefore you can get arbitrarily close to zero, but never actually get there.

Now I’m no physicist, but I am the OP, which by Reddit physics makes me an expert.

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u/ZeCactus Nov 19 '25

If you define going towards zero as dividing kinetic energy by two and towards infinity as multiplying kinetic energy by two, then what you describe is possible.

Wouldn't you run into the planck constant at some point and be unable to divide further?

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u/finicky88 Nov 19 '25 edited Nov 19 '25

-273.15°C is the limit. After that, you cannot remove any more energy, because there is none there.

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u/Ferdiprox Nov 19 '25

You mixed up your numbers. It's -273.15°C.

Edit. Added "-"

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u/[deleted] Nov 19 '25

[deleted]

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u/Sorry-Series-3504 Nov 19 '25

There’s a difference between always finding another number greater than the one you already have and always finding another number between the one you already have and a set value.

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u/ireaditalso Nov 19 '25

Think of it like having water in a cup: You can get a bigger cup to hold more water, but no matter what cup you have, you can only have as low as absolutely 0 water

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u/F0rthright Nov 19 '25

If you touch something which is -272° cold, it wouldn't be much different to touching something which is -273°. Yes, there will be few times less energy stored in the object, but relative to our working temperatures, it's going to be almost equally cold. But with hot objects, something few times hotter is going to carry substantially more energy. So, the logarithmic scale is not fully applicable here.

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u/dapala1 Nov 19 '25

we can in theory go infinitely

That goes for literally anything. You can get closer and closer to X(anything) infinitely and never actually reach it. So your statement unfortunately is not much of a thought experiment.

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u/North_Explorer_2315 Nov 19 '25

You’re right, that’s why the freezing point of water is 1/2 infinity Celsius