The Coolest Spot in the Universe

The space station's new fridge!

It's about the size of a beer cooler, but even cooler (if anything can be cooler than a beer cooler). It promises to produce what might be the coldest spot in the entire universe. (Just a spot, big enough for a few atoms.) They are shooting for 200 billionths of a degree Kelvin.

Livescience says: "At that temperature, atoms slow down so much that they begin to enter the same quantum state, exhibiting the same amount of energy as one another, NASA representatives explained. Their behavior becomes more wavelike, and they start to synchronize like a line of dancers --- a phenomenon known as a Bose-Einstein condensate."

While these have already been produced, they only last for a second or so on Earth. This new experiment is shooting for a lifetime of up to 10 seconds.

After it is set up by the astronauts on the space station, it will be run continuously by remote control from Earth.

https://www.nasa.gov/mission_pages/stati...d_atom_lab

https://coldatomlab.jpl.nasa.gov/

https://coldatomlab.jpl.nasa.gov/mission/

https://www.livescience.com/62618-coldes...verse.html

https://en.wikipedia.org/wiki/Bose%E2%80...condensate

Quote:Their behavior becomes more wavelike,

OK, I'm confused. Wavelike sounds like a poor choice of word. They're not talking with regard to atoms and wave/particle duality are they? Makes it seem to a layperson like myself that all we need to do is cool matter to zero Kelvin or less and the particle function collapses, if there is such a thing.

By behavior I assume like waves of liquid. Is that it?

(May 21, 2018 10:54 PM)Zinjanthropos Wrote:

Quote:Their behavior becomes more wavelike,

OK, I'm confused. Wavelike sounds like a poor choice of word. They're not talking with regard to atoms and wave/particle duality are they? Makes it seem to a layperson like myself that all we need to do is cool matter to zero Kelvin or less and the particle function collapses, if there is such a thing.

By behavior I assume like waves of liquid. Is that it?

Yes, they are talking about wave/particle duality. A Bose-Einstein condensate can occur from bosons because they can share quantum states (position, energy, etc.), unlike fermions. Photons are bosons, but atoms composed of the right number of fermions and bosons, that give it an integer spin like a boson, also act as bosons. Even molecules composed of such atoms can be made to condense.

There's no particle function, because the nature of particles means that their position is known, which doesn't require any probability to determine.

The quantum wavelike behavior is that one such atom could interfere with itself and create an interference pattern like light in the two-slit experiment.

(May 22, 2018 12:46 AM)Syne Wrote:

(May 21, 2018 10:54 PM)Zinjanthropos Wrote:

Quote:Their behavior becomes more wavelike,

OK, I'm confused. Wavelike sounds like a poor choice of word. They're not talking with regard to atoms and wave/particle duality are they? Makes it seem to a layperson like myself that all we need to do is cool matter to zero Kelvin or less and the particle function collapses, if there is such a thing.

By behavior I assume like waves of liquid. Is that it?

Yes, they are talking about wave/particle duality. A Bose-Einstein condensate can occur from bosons because they can share quantum states (position, energy, etc.), unlike fermions. Photons are bosons, but atoms composed of the right number of fermions and bosons, that give it an integer spin like a boson, also act as bosons. Even molecules composed of such atoms can be made to condense.

There's no particle function, because the nature of particles means that their position is known, which doesn't require any probability to determine.

The quantum wavelike behavior is that one such atom could interfere with itself and create an interference pattern like light in the two-slit experiment.

Thanks Syne. I was on the right track except the train wouldn't budge. 

Makes me think.....NASA hopes BEC lasts 10 seconds in space. Why is this important? Has someone suggested the universe was once sub Kelvin and all matter consisted of waves in the first seconds or whatever of BB or that matter was always present but existed as waves, making the BB a simple warming trend? For theists that would be like God taking the universe out of the freezer and thawing it in the microwave, wouldn't it?

(May 22, 2018 01:08 AM)Zinjanthropos Wrote: Thanks Syne. I was on the right track except the train wouldn't budge. 

Makes me think.....NASA hopes BEC lasts 10 seconds in space. Why is this important? Has someone suggested the universe was once sub Kelvin and all matter consisted of waves in the first seconds or whatever of BB or that matter was always present but existed as waves, making the BB a simple warming trend? For theists that would be like God taking the universe out of the freezer and thawing it in the microwave, wouldn't it?

So far, it's not even theoretically possible to reach absolute zero (0 Kevins). Even if we could reach absolute zero, it would be the lowest energy state possible in the universe. Either way, "sub Kelvin" isn't a thing.

The additional observation time may allow for more elaborate experiments of BECs.

(May 22, 2018 02:09 AM)RSyne Wrote:

(May 22, 2018 01:08 AM)Zinjanthropos Wrote: Thanks Syne. I was on the right track except the train wouldn't budge. 

Makes me think.....NASA hopes BEC lasts 10 seconds in space. Why is this important? Has someone suggested the universe was once sub Kelvin and all matter consisted of waves in the first seconds or whatever of BB or that matter was always present but existed as waves, making the BB a simple warming trend? For theists that would be like God taking the universe out of the freezer and thawing it in the microwave, wouldn't it?

So far, it's not even theoretically possible to reach absolute zero (0 Kevins). Even if we could reach absolute zero, it would be the lowest energy state possible in the universe. Either way, "sub Kelvin" isn't a thing.

The additional observation time may allow for more elaborate experiments of BECs.

Did they or didn't they? 

https://www.accuweather.com/en/weather-n...ro/3684063

If 0° Kelvin was possible, how would that affect matter?

(May 22, 2018 03:01 AM)Zinjanthropos Wrote:

(May 22, 2018 02:09 AM)Syne Wrote: So far, it's not even theoretically possible to reach absolute zero (0 Kevins). Even if we could reach absolute zero, it would be the lowest energy state possible in the universe. Either way, "sub Kelvin" isn't a thing.

The additional observation time may allow for more elaborate experiments of BECs.

Did they or didn't they? 

https://www.accuweather.com/en/weather-n...ro/3684063

If 0° Kelvin was possible, how would that affect matter?

Well, "colder" is a misnomer.

Oddly, another way to look at these negative temperatures is to consider them hotter than infinity, researchers added.
...
With positive temperatures, atoms more likely occupy low-energy states than high-energy states, a pattern known as Boltzmann distribution in physics. When an object is heated, its atoms can reach higher energy levels.

At absolute zero, atoms would occupy the lowest energy state. At an infinite temperature, atoms would occupy all energy states. Negative temperatures then are the opposite of positive temperatures — atoms more likely occupy high-energy states than low-energy states.
- https://www.livescience.com/25959-atoms-...-zero.html


A system with a truly negative temperature is not colder than absolute zero. Rather, a system with a negative temperature is hotter than any system with a positive temperature, in the sense that if a negative-temperature system and a positive-temperature system come in contact, heat flows from the negative to the positive-temperature system.
- https://en.wikipedia.org/wiki/Absolute_z...mperatures

If absolute zero were achievable, it would seem to violate some fundamental quantum mechanics, but even near absolute zero, matter takes on odd properties, like superconductivity and Bose-Einstein condensates. In some sense, you can kind of think about reaching absolute zero like reaching the speed of light (although we can get much closer to zero). The closer we get the closer the effort required approaches infinity.

What's the temperature of nothing?  Would quantum fluctuations produce a temperature?  Sorry, was watching Krauss lecture last night .

Even empty space has a zero-point energy, and since temperature is basically a measure of energy, that means that, yes, quantum fluctuations do produce temperature.

(May 22, 2018 08:23 PM)Syne Wrote: Even empty space has a zero-point energy, and since temperature is basically a measure of energy, that means that, yes, quantum fluctuations do produce temperature.

What's warmer, quantum fluctuations or one photon? Remembering seeing a story headline once about a scientist  saying the BB was the result of a single photon. I think story also said all that we see is that single photon....Wonder where they put that guy?