The laws of thermodynamics

[Pezzoni]

Is this an area of science in which we are likely to see change in the future? Are the laws of thermodynamics likely to be improved, or demonstrated to be incorrect, or are they so fundamental that this is an impossibility?

This is what I think about while having a dump. I worry about me sometimes.

[Singular Intellect]

I fully expect the first law of thermodynamics to be altered or dismissed at some point in the near future.

Although I will readily point out I cannot justify this expectation at this time.

[kc8tbe]

Well, I'd venture to say that all scientific law/theories get revised as time goes on. Newton's laws, as a classic (no pun intended) example, don't quite work as expected near the speed of light. As another example, consider the numerous differences between Mendelian inheritance and the present state of genetics. I don't see why thermodynamics would be an exception to this trend.

Consider that researches at ANU claimed to have "broken" the second law of thermodynamics on the quantum scale (link to pdf), although they would not be the first group to think this.

[Molyneux]

I HOPE that the law of conservation of matter and energy does not hold under all circumstances; it would make the universe a much more interesting place to live.

[Bronx]

Science is in no way absolute.

[Lord Zentei]

Is this an area of science in which we are likely to see change in the future? Are the laws of thermodynamics likely to be improved, or demonstrated to be incorrect, or are they so fundamental that this is an impossibility?

Though no scientific theory is immune to being overturned, I'll have to voice my skepticism on the possibility.

Seeing as the laws of thermodynamics can be shown to be based on statistical laws, I find the prospect that they will be changed remote at best.

[Fingolfin_Noldor]

There was talk that the 2nd Law might be invalid for open systems, but certainly not for isolated ones. If it's violated, I think there's a compensation mechanism somewhere.

And... by saying that the 1st law of thermodynamics will be overturned, you obviously do not understand what you are talking about.

[Fingolfin_Noldor]

To clarify, the 2nd law should be valid for isolated systems, but if we pick up a portion of an open system, it might appear violated, but in truth that portion interacts with the rest of the open system. I might have my terminology wrong here though.

[darthbob88]

And... by saying that the 1st law of thermodynamics will be overturned, you obviously do not understand what you are talking about.

Neither do you. If I read that correctly, they are hoping it does not hold in all conditions, necessitating an alteration of the law, rather than a total replacement. This would make things like FTL possible, making things much more interesting. Unlikely, but it would be cool.

[Darth Wong]

There was talk that the 2nd Law might be invalid for open systems, but certainly not for isolated ones.

That doesn't make sense. The 2nd law does not preclude the loss of entropy in an open system, so it would not be violated by the loss of entropy in an open system. This is like saying that the law of gravity is violated by airplanes.

[Isana Kadeb]

To clarify, the 2nd law should be valid for isolated systems, but if we pick up a portion of an open system, it might appear violated, but in truth that portion interacts with the rest of the open system. I might have my terminology wrong here though.

I think you mean a closed system there. It seems you crucified the terminology .

[Isana Kadeb]

I think I might have done some crucifying as well, is the universe an isolated system or a closed on (since its expanding)?

[kc8tbe]

The universe is both isolated (since it does not gain or lose mass) and closed (since it does not gain or lose energy). The fact that it is expanding has no bearing on this.

[Admiral Valdemar]

There are instances where the laws have been flouted before. I believe reversible computing essentially destroys heat by computation and is used for MRI samples where extremely low temperatures are needed (millikelvin). I also recall another story on some other unique physical phenomenon, but the details escape me right now.

[Fingolfin_Noldor]

There was talk that the 2nd Law might be invalid for open systems, but certainly not for isolated ones.

That doesn't make sense. The 2nd law does not preclude the loss of entropy in an open system, so it would not be violated by the loss of entropy in an open system. This is like saying that the law of gravity is violated by airplanes.

The most prominent example for this, is the vacuum energy flux. A "electron-positron" pair is created, which itself flouts the 2nd law, and but the subsequently annihiliate which essentially "unviolates" the law. The reasoning is that though this "electron-positron" pair-annihiliation (if I recall the terms correctly again) occurs, the overall energy of the system does not change, so the net entropy increase is zero.

Neither do you. If I read that correctly, they are hoping it does not hold in all conditions, necessitating an alteration of the law, rather than a total replacement. This would make things like FTL possible, making things much more interesting. Unlikely, but it would be cool.

Look, the 1st law states that to bring about a change of energy of a system, one has to apply a change of heat and do work on a system. I have yet to hear of a system that can work for an eternity without any influx of energy of sorts. FTL requires energy and I have yet to hear any violations of this law yet. Else, we would have an infinitely running machine by now.[/quote]

[darthbob88]

Neither do you. If I read that correctly, they are hoping it does not hold in all conditions, necessitating an alteration of the law, rather than a total replacement. This would make things like FTL possible, making things much more interesting. Unlikely, but it would be cool.

Look, the 1st law states that to bring about a change of energy of a system, one has to apply a change of heat and do work on a system. I have yet to hear of a system that can work for an eternity without any influx of energy of sorts. FTL requires energy and I have yet to hear any violations of this law yet. Else, we would have an infinitely running machine by now.

[/quote]
I am aware of that, conservation of mass-energy and all that. What I was referring to was the possibility of that law failing at edge conditions, akin to Newtonian mechanics becoming inaccurate at high-speed and/or low mass. This would allow, if my logic is correct, for FTL travel/communications. Unlikely, damn near impossible, but it would be very cool if it were so.

Regarding the inviolability of the 1st/2nd law: I found a figure somewhere suggesting that the odds of successfully reversing entropy or violating conservation of energy, are equivalent to a million monkeys cranking out all of Shakespeare's works, in chronological order, several trillion times over.

[drachefly]

The most prominent example for this, is the vacuum energy flux. A "electron-positron" pair is created, which itself flouts the 2nd law, and but the subsequently annihiliate which essentially "unviolates" the law. The reasoning is that though this "electron-positron" pair-annihiliation (if I recall the terms correctly again) occurs, the overall energy of the system does not change, so the net entropy increase is zero.

This is not how it actually happens. It is a cartoon which helps visualize the situation. In Real Life (tm), the first law is not violated at any moment in the process.

That is because the vacuum is an energy eigenstate. That is, it has precisely defined energy. It is not an eigenstate of the electron/positron field operator, which means the number of particles in it is not precisely defined.

The 'borrowing energy' line is again a cartoon. The real solution is that mass is, roughly speaking, a resonance phenomenon with energy as the driving force and lifetime as the amplitude. Briefly existing particles don't need a high quality factor, so it's okay if they are far off-resonance. In other words, these electrons may have parameter mass that's the same as usual, but there is much less energy involved in their creation than one would expect.

[Fingolfin_Noldor]

The most prominent example for this, is the vacuum energy flux. A "electron-positron" pair is created, which itself flouts the 2nd law, and but the subsequently annihiliate which essentially "unviolates" the law. The reasoning is that though this "electron-positron" pair-annihiliation (if I recall the terms correctly again) occurs, the overall energy of the system does not change, so the net entropy increase is zero.

This is not how it actually happens. It is a cartoon which helps visualize the situation. In Real Life (tm), the first law is not violated at any moment in the process.

That is because the vacuum is an energy eigenstate. That is, it has precisely defined energy. It is not an eigenstate of the electron/positron field operator, which means the number of particles in it is not precisely defined.

The 'borrowing energy' line is again a cartoon. The real solution is that mass is, roughly speaking, a resonance phenomenon with energy as the driving force and lifetime as the amplitude. Briefly existing particles don't need a high quality factor, so it's okay if they are far off-resonance. In other words, these electrons may have parameter mass that's the same as usual, but there is much less energy involved in their creation than one would expect.

Are you refering to the 1st or 2nd law? I understand the 1st law isn't technically flouted since the net energy change is zero, but the 2nd law is concerning entropy.

[Isana Kadeb]

The universe is both isolated (since it does not gain or lose mass) and closed (since it does not gain or lose energy). The fact that it is expanding has no bearing on this.

I think you've got the terminology wrong here as well. A closed system is one that can exchange heat and work with its surroundings. The expansion of the universe is relevant as the number of possible states for the particles is ever increasing, closed systems are those with a constant volume.

[Wyrm]

Are you refering to the 1st or 2nd law? I understand the 1st law isn't technically flouted since the net energy change is zero, but the 2nd law is concerning entropy.

Obviously, drachefly was talking about the first law. The second law concerns entropy, which is not connected in any fundamental manner with the precise number of particles in the system... and besides which entropy is the macroscopic state variable of the system conjugate with temperature, just like volume is conjugate with pressure. Changes in entropy are even physically measurable to boot, at least in principle. Not so with virtual particles.