/sci/ - Science & Math

Not the first time.

But - why would temperatures lower than the lowest appear? 0 kelvin is no motion at all, and - what is negative motion?

>>5410174

if my calculations are correct, this will lead to faster than light travel, in our lifetime.

>>5410227
gosh I wonder if there's an article somewhere that would lay out the basic idea for us

>>5410229
Oops, scratch that, forgot to carry the one.

>In theory, if the situation is reversed, with more particles having higher, rather than lower, energies, the plot would flip over and the sign of the temperature would change from a positive to a negative absolute temperature
Wouldn't this just mean that the system is warmer?

>>5410227
You do not understand temperature. It might be easier to think of temperature as energy. 0 kelvin probably is not possible. It's like a graph with 0 as an undefined point

>>5410259
yes, any negative temp is hotter than any positive temp, the Kalvin scale kind of wraps around with 0 from the positive side the coldest and 0 from the negative side the hottest.

this has been done countless times in lazers and magnetic systems.

Im interested in this, but im just a simple engineer so Im not understanding this part.

''Normally, most particles have average or near-average energies, with only a few particles zipping around at higher energies. In theory, if the situation is reversed, with more particles having higher, rather than lower, energies, the plot would flip over and the sign of the temperature would change from a positive to a negative absolute temperature, explains Ulrich Schneider, a physicist at the Ludwig Maximilian University in Munich, Germany.''

Why is this 'plot' flipped over? what do they mean by that?
If there are more particles having higher, rather than lower, energies, wouldnt this result in a higher absolute temperature?

>>5410306

So when they went 'colder' than zero they in fact went warmer?

>>5410313
So we could heat the colder stuff to make it colder?

Solution to global warming?

>>5410311
from thermodynamics temperature is defined as the relationship between entropy and energy.

usually if you increase the energy you open up more states that the particles can be in, for example a larger distribution of speeds, thus increasing the entropy. in a normal system this just increases without limit with entropy getting larger as energy gets larger. but if you can put a limit on the amount of states possible, like letting each particle have some maximum energy, then eventually all the particles will be in that state, so the entropy is lower, thus entropy goes to 0 as energy gets larger, so be casue this relationship between energy entropy is reversed, the temp is negative.

>>5410281
>It might be easier to think of temperature as energy.
No, that misinterprets the very definition of temperature. Fucking physicists ruin everything because you are to lazy to develop proper terminology.

>>5410327

at the quantum level there is no concept of "heat" or "temperature".

>>5410318
Thank you this makes sense.

impressive

i think this will win a Nobel prize

>>5410327

I have always thought each physicist should have teams of liberal arts majors to name things for them.

Because Christ physicists suck at that shit.

"Big bang" is misleading.

"Atom" comes from the Greek word for "indivisibile," so as soon as we discovered the "subatomic" world, we created a word which meant "The divisions of the indivisible." which is oxymoronic.

Then there's the fact that half these niggas are so egotistical they name their theories after themselves rather than what the theory is supposed to explain, which would be much more helpful.

Imagine if "Calculus" were called "Oppa Newton Style."

>>5410437
"Quark" comes from James Joyce's Finnegan's Wake, so we're halfway there.

>>5410437
Trying to change a name like that is idiotic. And most physicists do not name things after themselves, other people start that. It's just a fucking name.

>>5410437
Taking Multivariable Oppa Newton Style would be cool as fuck.

Isn't temp. A measure of atoms relative movement, and with higher movement a higher temp. Is archived. And 0K is no movement at all. How the fuck do you get negative movement? That's like deceleration, there's no such thing.

so really what they mean... is .. we just introduced more energy to a system than it can hold, and things started going backwards.. makes sense.. that extra energy doesn't want to cooperate, it wants to get outta there. So is dark energy the same thing as this.. explaining its reversed characteristics.

"If built, such systems would behave in strange ways, says Achim Rosch, a theoretical physicist at the University of Cologne in Germany, who proposed the technique used by Schneider and his team3. For instance, Rosch and his colleagues have calculated that whereas clouds of atoms would normally be pulled downwards by gravity, if part of the cloud is at a negative absolute temperature, some atoms will move upwards, apparently defying gravity4."

Wtf am I reading?

>>5410666
Think of temperature not as actually things not moving.. but a boundary to how many states they can have. At absolute 0 a particle can have no states, it can't exist technically at absolute 0.

To go below 0 we give a particle more energy than it can hold in states. Typically there is no upper boundary to states, so temperature is unbounded by states and related to energy, with a lower state bound. in this case it also has an upper state bound as well.

>>5410672
The invention of exotic matter that will give us the ability to make stargates?

>>5410666
no, temperature is how fast the entropy changes relative to the energy, you can use that to derive the case for an idea cas and in that case it happens to only be a function of the velocity of the particles.

>>5410667
no, you don't reach the maximum energy, but as you get nearer to it the entropy gets lower.

dark energy made in lab
>its happening

>>5410227
>0 kelvin is no motion at all
That's a popular misconception. It applies to ideal gases, but not all systems. Harmonic oscillators as well as a whole lot of other systems have zero-point energy.

>>5410318

So the definition of absolute zero no longer applies because it was redefined and the particles exhibit more energy than is 'possible' as per thermodynamics all the while these particles are actually not at absolute zero (the real one) as they haven't stopped moving and for whatever reason the equipment will always ready lower than it's actual temperature.

I loved that movie as a kid, fuck