30°C is 303 Kelvin. Half of that is 151 Kelvin, which translates into a fairly mild -122°C!
Takes out hockey stick
New strategy to prevent global warming: just freeze all of the CO2 out of the air!
Dry snow doesn’t sound like too bad of a proposition on its own.
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.
the sequestering step is actually kinda easy, it’s the sun shield that’s the hard part
That sounds great. I bet it would be even easier to do on earth. If anyone gave a shit.
Aka a cool 272 Rankine for our US folks.
I would be willing to bet there are more people in the US using Kelvin in their jobs than Rankine.
Lb-mole? That one I’m not sure.
To me, these wanna-be scientific units are weird, like, just use metric at that point 😅
Also 1000th of an inch. Like, come on! You’re just teasing us
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.
hmm but there will surely be a lot of phase changes with a drop in energy so substantial. we need our top scientists on this asap
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
😱
Careful, half of what, kelvin?
That is indeed the joke.
Absolute-ly
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.
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. When working with monkeys paw or genies always declare your units and reference frames.
No.
wdym range from 0 to 50?
0 is the freezing point of water 50 is the boiling point.
If it’s 30°c outside, it will be only be 15 after the wish, thus fit what the character said
sure but you shouldn’t take halves on a scale with an arbitrary 0
True, but my joke wasn’t meant to be scientifically accurate at all. We have a genie here. They don’t care about science. Apart from monkey paw science
deleted by creator
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.
But °C was mentioned in the units, and its well understood that 0°C is a cold temperature for humans.
I’m not a fan of marketing doublespeak either, but I think the right scale and right terminology was used here. They cut the temperature in half, in Celsius, on the basis that 0°C is very cold.
Thats where the physics comes in. if the temperature is halved in terms of celsius from 70° to 35°, if in your case the temperature starts at 100°, the same energy difference would only bring the temperature down to something closer to 65° than 50°.
the specific cooling capacity of the cooler in question only “halves” the temperature if you start at a very specific point.
My entire argument rests on the premise that 0°C is a rational start point for both C and F, but I concede that halving something doesn’t explain absolute changes
But centigrade isn’t a measure of absolute units and is disingenuous. Using your argument it requires the consumer/reader to make a number of inferences or assumptions which isn’t a good method of communication in general. It is perfectly valid to say that the cooler took CPU temperatures from 70°C to 35°C.
Why not just say that. It’s an impressive stat!
Scales exist for a reason. Cutting 70°C in half is by definition -101.5°C. But let’s assumed somehow everyone is on the same page and that anything below 0°C should just be ignored in this specific scenario and not any other (confusing right?), saying the temperature was cut in half is still confusing! Half from where? Did it go from 20°C to 10°C? From 80°C to 40°C? It just doesn’t mean anything and as said before I would argue just stating the numbers is more impressive and informative.
I agree that the numbers should just speak for themselves
Cutting 70°C in half is by definition -101.5°C
I’d argue here that no one would make this leap nor mental calculation, and most people would just divide X by 2 and gauge what the resulting Y is based on their familiarity with the weather.
it requires the consumer/reader to make a number of inferences or assumptions which isn’t a good method of communication in general
They still have to make these inferences to understand whether or not 70 to 35 is a remarkable feat or not.
If it’s 30 / 2 = 15, people would think “Huh, 15 is pretty cool compared to room temperature ~ 20ish , that’s significant”. If it’s 90 / 2 = 45, people would think “Huh, both 90 and 45 are pretty hot, but it seems like a meaningful reduction nonetheless.”
I dunno, maybe I’m overdefending this
All I can say is that in my professional career where I have to write technical reports and summarize technical information I would never represent it that way, and I would be concerned if a colleague, customer, or supplier did it even if they were communicating it to a non technical audience. I would also call out my employer or management if they ever tried to change the representation of the data to something like this.
That could say more about me than anything else, but that’s where I am at.
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.
thanks, this makes a lot more sense.
That being said, 70C down to 35C is a huge difference, relative to the temperature ranges we live in
I just want to chime in and say I appreciate your willingness to absorb knowledge, as well as not doing the “I was mistaken so I’ll delete my comment” thing so that other people can read along and learn as well.
It would certainly be a good CPU cooler. Marketing just ran away with claims they can’t back up.
Here’s an actual example of this sort of thing (starting around 3:22): https://www.youtube.com/watch?v=w8kprUGy57E&t=233s
308.15K is not half of 343.15K
Do you also say “the temperature in the freezer has doubled” when it goes from -12°C to -24°C? Not saying that would be disingenuous with your arguments.
Usually that should mean it cuts the difference ambiant and CPU in half. Anything else would just be stupid or a lie.
perhaps it cuts generated temperature in half, ie idle cpu is 50C, stock 70C, and aftermarket 60C
That’s not how it works, an “idle” CPU is already generating a not insignificant amount of heat. That why you measure the difference against ambiant air if you’re at all serious about it.
For anyone questioning this logic, try running your “idle” CPU without a heatsink of any kind.
Obviously we’d all die but I wonder how exactly. This would make a good question for Randall Munroe.
90 F to Kelvin, halved and converted back, is approximately -190.
It’s difficult to find data on what exposure to that temperature would do, the threshold for an extreme cold warning (meaning absolutely do not go outside without heavy protection unless you want necrotic frostbite) is about 150 F warmer than that.
It depends on conductive and convective transfer at that point. The atmosphere would be vastly different as that’s well below the point where CO2 would snow out but you should still have enough gasses to flash freeze you.
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
Doom near the entire planet
Next Summer
Coming to theaters near you
arguably setting zero to absolute zero is just as arbitrary
How so? Absolute zero is the coldest possible temperature, it’s physically impossible for an object to be colder. Saying that’s arbitrary is like saying it’s arbitrary to define 0 m/s as not moving.
0 m/s as not moving.
Well, technically…
If the earth rotates but the object doesnt does it move?
If the object remains still in space but the earth moves away from it, does it move?
Every decision is arbitrary in some way. We, as humans, defined it would be better to arrange the periodic table a certain way, based on characteristics of the elements, but the characteristics chosen are arbitrary. We could’ve just chosen a different set for ordering, like alphabetical.
Tho, that’s a correct (IIRC) yet weird usage of “arbitrary”, and since language exists to talk, not to be correct, we might as well not use this definition of arbitrary and stick to what conveys information better.
Edit: I’m wrong! perhaps “correct” was the word I meant to say, not sure tho.
It’s still assuming a scale. It’s actually worse because the scale is implied by context.
The context of… reading the fabric of the universe?
You’re right, that is totally irrelevant to… a physicist.
I see you’re trolling, so I look forward to your condescending response, but to be successfully condescending you have to be at least somewhat convincing in displaying intelligence, if you can manage that then this whole argumentative act will go much better and people will get much angrier.
TLDR, Try the same troll tactic but with less incompetence for better results.
Zero kelvin is very contextually useful. Put very simply it literally relates to the motion of atoms. At zero, they move zero.
What? What context? The scale is the same as Celsius which is derived from the properties of water. And 0K is when there is absolutely no heat energy in the thing being measured. There is no context where this is not the case.
The one where a human is speaking in English and referring to a season and the temperature is more than significant context. I hope this helped you; it seems that you’re one of those people who lack the capacity to infer from available data.
People don’t use Kelvin when referring to seasons. Sure, there’s plenty of ambiguity if someone says it’s 32° out without specifying the units, and you can infer from context, but that has nothing to do with Kelvin starting at absolute zero. Saying “degrees” immediately rules out Kelvin as a unit.
Being condescending actually doesn’t help a conversation.
Halving something requires a scale…
The scale doesn’t matter, double is always double. No matter if expressed in 1m is half of 2m, or 3ft is half of 6ft. Same is true for temperature, als long as the zero point is fixed.
Scale always matters, it is the anchor point for shared communication.
Double is a scale in itself, it assumes the first thing as 1 and the second thing as 2. The are no other scales needed when I say something is double the other thing. The other thing is the scale here.
holy shit lol
Probably want it between the winter temperature and the current summer temperature, but genies are traditionally fickle and pounce on any ambiguity
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?
This is why I hire my attorneys from Avernus. Don’t nobody got lawyers like Hell has lawyers. If you’re trying to pull one over on a genie, you’re going to need either devils or fae. And the devils are more likely to respect their contract, including any loopholes you manage to find in it.
Considering making a wish on a shooting star? Been granted a wish scroll by an obnoxious DM? Give a lamp a handjob only for it ejaculate a genie? Then you need the services of Nine Hells Legal! Our prestigious law firm can draft up an ironclad wish for all your mortal needs! No loopholes guaranteed or your soul back.
All fees to be paid in souls. Retainer fees are nonrefundable. The souls of the sacrificed and those otherwise deemed to fall within the purview of Hell are nonrefundable. “Nine Hells Legal” is a wholly owned trademark of Sir Asmodeus, esq. The archduke of the Nine Hells.
First wish, a lawyer who specializes in genie law. Unfortunately, the lawyer draws up a contract that screws you out of most of your wishes, not because of the genie’s influence, but because they’re a lawyer.
Which room though?
what, you never heard of the room temperature room?
It’s a room made from platinum-iridium, and kept in a triple-locked vault at the International Bureau of Weights and Measures in France.
unfortunately, opening the door changes the temperature, so in practice instruments are calibrated from copies of the room built at other metrology institutions around the world.
The indoor temperature is always at room temperature and vice versa. It’s not constant though.
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.
As long as the mixture of the substance remains constant and there are no phase changes, heat energy and temperature are linear and half the heat energy is half the temperature. In reality this only works for solids because otherwise, halving the heat energy would definitely involve phase changes.
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.
That wish just condenses the atmosphere of half of the planet for half of the time. How do you like your puddles of liquid oxygen now?
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.
What makes Kelvin absolute, and why is Celsius “wobbly”?
I failed physics in high school
0 K is like when there is 0 heat basically, while celsius isn’t. Imagine a unit for distance called “goob” where 0 goobs is 100 m and 1 goob is 115 m. In that case the goob unit would behave differently than a meter when you multiply and divide because 0 of the units don’t actually correspond to “nothing” in a physical sense. That’s exactly how the Celsius scale is, with zero being placed somewhere arbitrarily, not at a physical zero.
i feel like i need more goob in my life. do you sell rulers?
Bit of an awkward scale for a ruler, but I can sell you one from -6.6666666… to -6.65 goobs.
absolute scales are still arbitrary. you would probably want to use a scale that measures “perceived heat” which is different than average kinetic energy
Kelvin is just our word for it, but that is the point of “no heat”. It isn’t arbitrary, there is no “negative kelvin” just like you cannot make something colder than absolute zero.
So if you take the difference between “coldest possible temp” and “average summer temp”, then slice it in half, you’re getting temperatures that would kill most life on earth.
Just to nitpick, there are negative kelvins. I don’t really understand it, myself, but I know it exists due to the specifics of how temperature is defined. Negative kelvins are actually extremely hot.
just because it has a reason doesn’t make it not arbitrary. you can ultimately come up with a reason for all arbitrary decisions
Do you not understand what the word arbitrary means?…
Is there a way to distinguish between arbitrary and non-arbitrary? Or is literally everything ever arbitrary?
Is that Kurt Angle?
I think it’s acute angle
No, it’s Kur Tangle
Is it hotter down south than it is in the summer?
