Absolute Zero

[f95toli]

Originally posted by: Biftheunderstudy

BTW f95toli whats your area of research, I was a research assistant over the summer working with laser cooling of sodium.

Macroscopic quantum phenomena in superconducting circuits (i.e. solid state qubits etc). I never need to go below 20 mK (using a dilution fridge) but some of the other members of my research group work on time standards (clocks and frequency standards) and they use laser cooling.

 

[silverpig]

Originally posted by: f95toli

Originally posted by: Biftheunderstudy

BTW f95toli whats your area of research, I was a research assistant over the summer working with laser cooling of sodium.

Macroscopic quantum phenomena in superconducting circuits (i.e. solid state qubits etc). I never need to go below 20 mK (using a dilution fridge) but some of the other members of my research group work on time standards (clocks and frequency standards) and they use laser cooling.

Cool. We have a dilution fridge in our lab too. I'm doing single molecule transport, although most of the lab is focused on spin current.

 

[gerwen]

Originally posted by: superHARD

Originally posted by: andrewbabcock

Originally posted by: gsellis
Assuming Big Bang, I say about 30billion light years past the edge of the universe might be absolute zero. It would be completely void of any matter or energy. In theory of course.

The edge of the universe? There isn't one...The universe is infinitely large...

Isn't that theory up for grabs?

I think so, but it doesn't have to be infinite to not have an edge to go past. One of the theories is a finite universe without bounds (an edge). You could move in a straight line in any direction and eventually end up back at your starting point. It works in 3 dimensions just like it works in 2 for a trip on the surface of the earth. You walk in a straight line and end up where you started.

Used to drive me nuts as a kid thinking about what's beyond the universe.

 

[gsellis]

Originally posted by: bsobel

Originally posted by: gsellis
I say about 30billion light years past the edge of the universe

I say you flunked physics

I retook it!

 

[Minerva]

Originally posted by: silverpig
Actually, the more sensical quantity in thermodynamics is inverse temperature 1/T.

1/T = dS/dE

Inverse temperature is the rate of change of entropy with respect to energy. So, when you add energy to a thermodynamic system, how much does the entropy change? Of course you can just look at dE/dS, but then you are asking how fast does the energy of a system change as you increase its entropy. It's a little harder to think about that way.

It also makes more sense to use 1/T to describe temperature as absolute zero temperature would be infinite inverse temperature, which make more sense why we can't reach it.

What's also interesting is it is possible to have something at a temperature below absolute zero in certain contrived cases. What happens is the system then cools to negative infinity, flips over to infinity, and comes down from very hot to room temperature. This is possible as you just can't have something AT absolute zero, but you can have systems below absolute zero

Very interesting.

Good discussion guys.

 

[superHARD]

Originally posted by: gerwen

Originally posted by: superHARD

Originally posted by: andrewbabcock

Originally posted by: gsellis
Assuming Big Bang, I say about 30billion light years past the edge of the universe might be absolute zero. It would be completely void of any matter or energy. In theory of course.

The edge of the universe? There isn't one...The universe is infinitely large...

Isn't that theory up for grabs?

I think so, but it doesn't have to be infinite to not have an edge to go past. One of the theories is a finite universe without bounds (an edge). You could move in a straight line in any direction and eventually end up back at your starting point. It works in 3 dimensions just like it works in 2 for a trip on the surface of the earth. You walk in a straight line and end up where you started.

Used to drive me nuts as a kid thinking about what's beyond the universe.

Yeah, another theory is that the universe is kind of a figure 8. (at least that's how I picture it)...Wouldn't this theory be needed for the movie "Paycheck" to work?

 

[Roguestar]

Personally I'm waiting for the entropic heat death of the universe, when everything is at the same temperature and no work occurs.

I'll take the week off .

 

[Never Knows Best]

Well you can get very close to absolute zero using lasers to force certain gases together, which are suspended in a magnetic field. Then say if you took this apparatus and increased its speed relative to us then it would appear to get cooler and cooler, but it would never reach absolute zero. That is just for atoms and molecular movement. The electrons and everything else in the atom would still be spinning and it would still be causing gravitational pull and all that.

 

[Leros]

Originally posted by: Roguestar
Personally I'm waiting for the entropic heat death of the universe, when everything is at the same temperature and no work occurs.

I'll take the week off .

I like to jump around and shout that I'm destroying the universe.

 

[Soccerman06]

Originally posted by: gsellis
Assuming Big Bang, I say about 30billion light years past the edge of the universe might be absolute zero. It would be completely void of any matter or energy. In theory of course.

Before the universe was created (theory of course), the ball which contained all matter/anti-matter was infinitally hot. But once the Big Bang occured, the universe spread out at a speed faster than the speed of light because of the energy given, so since no electromagnetic radiation is able to move faster than the speed of light and if there was a particle outside of the Big Bang (say a foot away from the expanding universe), that particle would have 0K because there was no energy to give the partle any. That is the only way I could see a particle actually "having" 0 energy, ie temperature. This is assuming that there is a particle outside of the Big Bang expansion.

 

[mozirry]

If there was an absolute zero, wouldn't that mean there is an absolute maximum?

 

[xinoxide]

If there were an insulator capable of blocking all energy, it would have to be infinately dense wich translates into infinately massive right? that right there seems like a bigger problem than reaching absolute zero to me. element X if you will.

 

[f95toli]

Originally posted by: mozirry
If there was an absolute zero, wouldn't that mean there is an absolute maximum?

No, while in classical physics temperature is a measure of fast the particles are moving, the more precise definition involves their kinetic energy. No kinetic energy=absolute zero.
And while there is an upper limit to how fast a particle can move (speed of light) their is no limit to its kinetic energy.

 

[Soccerman06]

Originally posted by: f95toli

Originally posted by: mozirry
If there was an absolute zero, wouldn't that mean there is an absolute maximum?

No, while in classical physics temperature is a measure of fast the particles are moving, the more precise definition involves their kinetic energy. No kinetic energy=absolute zero.
And while there is an upper limit to how fast a particle can move (speed of light) their is no limit to its kinetic energy.

There is a limit, infinate.

 

[silverpig]

Originally posted by: Soccerman06

Originally posted by: f95toli

Originally posted by: mozirry
If there was an absolute zero, wouldn't that mean there is an absolute maximum?

No, while in classical physics temperature is a measure of fast the particles are moving, the more precise definition involves their kinetic energy. No kinetic energy=absolute zero.
And while there is an upper limit to how fast a particle can move (speed of light) their is no limit to its kinetic energy.

There is a limit, infinate.

You basically just said: "There is a limit. And that limit is the absence of a limit."

 

[mozirry]

Ah... do not forget the old saying "Infiniti + 1"

 

[xinoxide]

http://www.myphysicslab.com/spring1.html

graph velocity vs position. set the spring stiffness to 250.

let run for as long as you can.

the spring dampening would represent you trying to cool a particle. the rate at wich it slows