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Scientists report asymmetry between heating and cooling

phys.org

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Re: Scientists report asymmetry between heating and cooling

#51

Post by gumby »

i-use-nixos-btw wrote: post #9

> While no immediate practical applications exist, the researchers envision enhanced efficiency in micromotors, microscale cargo transport, and materials that can self-assemble or self-repair. Everyone who has ever written a grant application will recognise this wording.

> Everyone who has ever written a grant application will recognise this wording.

And then when they see the university publicity department article on the topic everyone will know that the wild claims on how it will revolutionize the future started out as a reluctant and hedged "practicality" sentence.

When a university pub office sends something out about a new theorem in pure math, the absurd "applications" claims are even funnier.

Re: Scientists report asymmetry between heating and cooling

#52

Post by WiseWeasel »

jackcosgrove wrote: post #35

My first thought upon reading the article was that absolute zero bounds coldness whereas there is no limit to how energetic a particle or bulk can be. Am I on the wrong track?

The upper limit would be magnetic force or materials required for containment in order to further energize.

Re: Scientists report asymmetry between heating and cooling

#53

Post by Roark66 »

bmitc wrote: post #3

I always feel a little stupid or strange reading a lot of these science headlines and introductions. I wasn't aware that people considered there to be a symmetry between heating and cooling. I thought that the entire point of thermodynamics is that they are asymmetric. Even the article mentions that it's been known that heating is more efficient than cooling.

Exactly, I always thought heating raises the entropy of a system and cooling puts it back in the "more orderly" state.

So of course it can't be symmetric. Just like breaking a wine glass, reversing that process takes a lot more effort.

Of course I have no idea if the above makes any sense, it's just an "intuitive understanding" I somehow got.

Re: Scientists report asymmetry between heating and cooling

#55

Post by juggertao »

ThalesX wrote: post #2

Does this mean ideal building design is as cool as possible and using energy for heating?

Depends on the climate.

Houses built in southern Italy are like that (white paint, shutters on windows, ...)

But in the Sweeden the opposite, optimize for heat.

Re: Scientists report asymmetry between heating and cooling

#56

Post by juggertao »

jackcosgrove wrote: post #35

My first thought upon reading the article was that absolute zero bounds coldness whereas there is no limit to how energetic a particle or bulk can be. Am I on the wrong track?

Absolute zero is very far away for all practical purposes to act as a bound.

Re: Scientists report asymmetry between heating and cooling

#57

Post by neilwilson »

ThalesX wrote: post #2

Does this mean ideal building design is as cool as possible and using energy for heating?

The other way around.

Generally it is best to create an insulated box that stays warm when it is very cold and then cool it down when it is hot - because the reason it gets hot is due to increased energy outside (normally the big glowy thing in the sky) and that energy can be captured and used to power a house sized fridge.

Energy to warm things up tends to be the sort of energy we can't really use any more.

Re: Scientists report asymmetry between heating and cooling

#59

Post by epgui »

jdksmdbtbdnmsm wrote: post #37
epgui wrote: post #22

Earlier quoted context omitted.

It’s the biggest stretch possible without it being technically dishonest. Everyone knows it: the researchers know it and gag a little as they write it, and the grant reviewers know it but pretty much require it without really ever saying that they require it (competitive landscape and all).

it exhibits a capacity to be full of shit with a straight face, which makes grant funders happy so grant reviewers view it as job security

No, it’s not the same thing as “being full of shit”. You took a nuance and you turned it into a carnival.

The incentive structures you hint at don’t make sense either.

Re: Scientists report asymmetry between heating and cooling

#60

Post by taylorius »

extractionmech wrote: post #7
bmitc wrote: post #3

I always feel a little stupid or strange reading a lot of these science headlines and introductions. I wasn't aware that people considered there to be a symmetry between heating and cooling. I thought that the entire point of thermodynamics is that they are asymmetric. Even the article mentions that it's been known that heating is more efficient than cooling.

> On the other hand, cooling at the microscopic level involves the release of energy from individual particles, resulting in a dampening of their motion. This process corresponds to the system losing energy, leading to a decrease in the intensity of particle movement. It actually makes sense, doesn’t it? Heating the object adds energy constructively. In cooling, energy removed from one particle may in fact be absorbe…

But isn't that passing on of energy from one particle to the next, just conduction? Why wouldn't it apply in the same way when heating?
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