30°C is 303 Kelvin. Half of that is 151 Kelvin, which translates into a fairly mild -122°C!
Takes out hockey stick
this post was submitted on 24 Oct 2024
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New strategy to prevent global warming: just freeze all of the CO2 out of the air!
I'm dreaming of a white Christmas
That's one of the ways proposed for terraforming Venus. Put in a sun shield to freeze the planet, let the CO2 snow down, then process the CO2 into something that can sequester it away so it doesn't just go back into the atmosphere after removing the sun shield.
Of course none of that is technically possible right now, but it's a lot easier on a planet that has no (known) life to destroy while working through the process.
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mmm, delicious carbonjack
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Wait, does it? Are joules in thermal energy per kelvin a purely linear relationship?
For the most part, it varies by material and state of matter, but assuming the chemical composition doesnt change and no material changes phase, then it is pretty close to linear in most materials.
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Fun fact: gas pressure changes linearly with temperature. If you make one of these plots at mild conditions you can extrapolate the line down to zero pressure and measure where absolute zero temperature is
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Granted. Celsius now range from 0 to 50
Edit: ... or whatever unit you prefer. It's still the same
Oh, it's way better than the alternative interpretation.
Half Kelvins?
30°C is 303.15K, half 151.575K is a nice and chilly -121.575°C lower than any recorded temp on earth by about 21°C.
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Reminds me of a time one of my friends was happy that it was going to warm up and said something like "it's going to be twice as warm tomorrow". It was going from maybe 20F to 40F or something.
That led to an interesting discussion.
This knowledge comes in handy with marketing BS around CPU coolers. If an aftermarket cooler gets a CPU to 35C when the stock cooler is at 70C, marketing will sometimes claim it cut temperatures in half.
I mean.... that's literally half though
edit: I am not a science man and I am in over my head in this argument
But it's not.
Celsius and Faernheit are interval scales, not rational scales. The absolute change from one number to the next is consistent, but since you can go into the negatives, 1 is not double 2.
Kelvin and Rankine are rational because they use an absolute zero.
to make the argument even simpler, that phrase wouldn't even mean the same thing to an english person as it would to an american.
In fahrenheit those temps would convert to 95f and 158f.
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If you convert those temperatures to Kelvin, they become 308K and 343K. Since Kelvin is absolute and we're measuring the same material, this tells you how much more thermal energy is there and their actual proportion to each other.
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308.15K is not half of 343.15K
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Careful, half of what, kelvin?
That is indeed the joke.
Absolute-ly
I use this as an example for interval vs ratio; you can't halve Celsius because it's an interval scale where zero is arbitrary. Kelvin is ratio as it has an absolute zero-- you very much can halve it and doom near the entire planet next summer
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Obviously we'd all die but I wonder how exactly. This would make a good question for Randall Munroe.
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A good genie would instantly invent a metric of "number of degrees in excess of room temperature"
I think it's fairly well known that there are no good genies. But otherwise, true.
For a present, I think it would be fun to have a contract lawyer draft up an ironclad 3 wishes contract
I was kind of thinking along the same lines. But to be truly ironclad, would you need a genie lawyer? Like not a lawyer who specialized in Genie Law, but an actual genie?
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Is the temperature scale directly proportional to the heat energy? I think the amount of energy needed to raise water by 1 degree is the same no matter the starting temperature for example. Is 100°K double the heat energy of 50°K?
Kelvin doesn’t have degrees btw you just say 50K or 100K because it’s an absolute temperature scale as opposed to an arbitrary or relative one like Fahrenheit or Celsius. I’d expect that the energy would be double though that’s more of a feeling.
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Well at some point you encounter a phase change, which complicates things, but mostly the heat capacity (how much energy it takes to raise the temperature) is fairly constant. In an ideal gas it is exactly constant, but that is a bit of an approximation, even if it works quite well for most gases.
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Could someone please explain?
Let's say the summer average is 30⁰C or 303.15 Kelvin
The absolute coldest possible temperature is -273.15⁰C, or 0K.
Halfway between absolute zero and 30⁰C/303.15K is somewhere around -121⁰C/152K
So if it were half as hot in the summer, it would be colder than ever recorded on earth.
In short, you don't want to use a temperature scale with an arbitrary starting point for doing calculations like this. The freezing point of water is no more or less arbitrary than the freezing point of oxygen or sodium or anything else. It's just one that's somewhat useful for everyday use. When handling calculations for multiplying temperature, you want an absolute scale like Kelvin.
Or Rankine if you're that kind of pervert.
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