"In this house we OBEY the laws of Thermodynamics!" Topic

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I am flabbergasted by this. Does this mean that all the Cs I got in college for physics and PChem should be upgraded to Bs?
Is there no end to this revisionism?

Ow, my brain hurts now.

More details here: link

Holy cheese.
Holy cheese.
HOLY CHEESE!!!!

Well, that shakes up the nicely layered salad, doesn't it?

I don't know what the other effects will be, but we're gonna have to revise and reprint a flotilla load of textbooks.

One of the stories I read about this emphasized that the TEMPERATURE was NOT below Zero, but that it was just … "negative temperature". ?

This is way above my skill level!

Theoretical thought exercise and nothing more I suspect. It relies on two impossible things – exceeding infinite temperature or being colder than absolute zero, both of which are oxymoron. How can you achieve something more than infinity or have less of something than a total absence?

I can think of plenty of sci-fi story lines for this ("We were attempting to achieve a temperature of less than absolute zero by dumping energy into an alternate quantum reference framework, but all we did was open a doorway to an alternate dimension, a dimension very different and horrifyingly alien to our own, a doorway we cannot close because something seems to be holding it open from the far side, a doorway that goes both ways…").

I keep reading this, and it just makes no sense.

I have studied quantum mechanics, at university as a short course more than Twenty years ago, but this runs almost counter to the weirdness that exists there. (however there may be evidence of other off the wall theories that come into play, such as zero point energy, speed of light changes that come into play at zero, etc.

if they can scale this up, then free heat pumps, entropy reduction devices, quantum ablation resistance, and about a thousand new theory of fluid thermodynamics. more likely it will not survive peer review.

Could be wrong, but I think it makes a bit more sense if you treat this as a classic SF "Anti-something" with resulting properties.

Seems to me they haven't gone beyond absolute zero, but "went the other way". It's like discovering that besides the number scale there is a negative number scale with weird new properties.

I love science. "Hey, if we do this, this, then this, I think this will happen."

Even if it's a failure in peer review, its quite possible that it leads to something else. Even if not, innovation requires the possibility of failure (something the paperclip counters need to understand).

OK. I can see what they've done. It's an interesting result, but the reporting of it is terrible.

The gas isn't at a below zero temperature. Temperature is the amount of kinetic energy in the substance. The atoms in this stuff still have KE, so it's still got temperature.

What they've changed is just how the energy is distributed amongst the atoms in the gas.

So energy diffuses between fluids by having 'collisions' between the atoms, which tend to average out their input KEs. Hence, generally, hot things give up their heat to cool things -- because there are more cool/slow atoms than hot/fast ones in the cool thing, so atoms from the hot thing are more likely to hit a cool/slow atom (and hence speed it up) than they are to get sped up themselves by hitting a hot/fast one.

This experiment has inverted that population; so now there's a fluid with a given temperature, but it's very contained in a small number of atoms which are unlikely to collide with others -- and if put in contact with a regular cooler fluid will absorb energy from the cooler one.

Works like this; imagine a decent temperature, half-filled bath. And you add a couple of buckets of absolutely boiling hot water. If you get in it, you'll get scalded.

If, however, you very carefully siphon the boiling water into one end without mixing it and then get in the other end, you'll be OK.

So for some purposes, the bath water can act as being cooler in places than the amount of hot water in it would suggest. Total amount of heat in the bath is the same -- and (since temperate is the measure of average heat energy) they're *technically* the same temperature. (If you measure the temp by putting a thermometer in both ends and averaging, the answer will be the same).

Likewise, this gas can act cooler than it is.

I note that doing so involves controlling the atomic motions using a laser lattice; this is how people do extreme cooling these days. Imagine an atom is whizzing towards you. You thump it with some photons off a laser, and it'll slow down. It's got COOLER.

Generally if you shine a light on something you'll slow some of the atoms down but the photons will speed others up (by pushing them away from the source faster as the photons kick them in the back). If you use a nicely tuned laser, the doppler effect means the apparent frequency of the laser, and hence whether the atoms can absorb the photons or not, changes depending on the relative motion of the atom to the laser source. Atoms moving away from the source aren't sped up because the laser frequency has been dopplered to one they don't interact with.

This stuff's not exactly cheap in terms of energy. So yes, you can make a heat-pump using this. And yes, the gas will have an efficiency of >1.

But your SYSTEM won't because you'll need to run the lasers…

Is this Maxwell's Demon at work here?

I'm with Goober. I'll wait a little longer. Sounds like the "faster than light" stuff initially reported by CERN.

CERN basically put their results out there and said – "We can't find the error, can anyone else?"

Question: In several places the articles refer to this phenomenon as "negative energy." I recall that the original concept for the Alcubierre Warp Drive was also "negative energy," which was considered only theoretical. Are these terms synonymous— that is, are the "negative energy" in the experiment and the "negative energy" mentioned by Alcubierre the same thing— or have the same words been used to describe completely different concepts?

" In several places the articles refer to this phenomenon as "negative energy.""

The gas still has positive energy content. It just has an inverted energy/population distribution.

" Sounds like the "faster than light" stuff initially reported by CERN."

Nah. It sounds way more plausible. FTL is defn "that breaks some rules" territory. This is just fiddling about with lasers.

I'm sure they did this in an episode of "Star Trek: Voyager".

Thanks KatieL – makes a bit more sense to me now.

I have seen news stories with the phrase "colder than absolute zero", which is NOT what the original said.