Zero point energy

[ScRaMbLe]

Whats the story? Has there been some announcement that I am unaware of? Why are respected members of the physics forum suddenly acknoledging the existance of zero point energy previously known as the aether? (not the old fashioned theory of ether).

Lethe -

because of quantum mechanics, the vacuum should be filled with a zero point energy. there are some thorny issues with this stuff (like, it might be infinite, or at least the theory makes predictions many orders of magnitude too large), but there can be no doubt that it is real. it was measured with the Casimir effect.

James R -

If the universe is infinite in size, then current findings suggest that the amoung of energy is indeed unlimited, since there is energy bound up in the fabric of space itself.

Crisp -

Void of virtual particles ? ... well, they say this does not exist. I am not sure what to think of it though

Hip hip and f**kin hooray!

 

[James R]

Zero point energy is not an aether (or ether).

 

[ScRaMbLe]

Ok, I dont want to confuse the issue with terminology, so FORGET I mentioned aether and ether (which are two different things, my understanding being that ether was a theory many years ago and was disproven, aether is a modern term which has been used as a name for the fabric of space/time in somewhat less than mainstream circles).

Please explain your understanding of zero point energy.

I'm not trying to be a smart-ass but it seems to me that certain posters opinions have changed. If I had access to threads dating back further than september I would quote them.

James R -

Quote

Let's see...

On the one hand, we have a super-secret military conspiracy which has managed to keep alien technology and zero-point energy devices secret from the public for years with no leaks.

On the other hand, there are about a million web sites which give detailed descriptions of all the secret UFOs, zero-point energy devices and alien autopsies which are supposedly happening all the time.

My question is: how do so many unqualified amateur conspiracy theorists manage to continually break through the top-level Pentagon security measures to get details of all the top-secret, conspiracy-protected stuff?

Isn't it much more likely that the conspiracy theorists just have incredibly overactive imaginations?

End quote

You will argue that you were merely saying that zero point energy harnessing devices dont exist.

Fair enough.

My point is you can see the general tone of dissent by bundling the concept with "alien autopsies" etc.

Anyway, I'm NOT trying to single you out, as I have always found you more open minded than most, I'm just making a point about the general feeling regarding zero point tech. There were MANY other posters who expressed similar views. Perhaps it was all just a mis-understanding of terminology.

Please dont take offense at this thread as it is not a witch hunt. It is obvious to anyone that your physics knowledge is far greater than mine, but your quote was the only one I could find. I realise that opinions change as new evidence is brought to light.

All I want to know is...

What is your understanding of zero point energy and do current theories allow the possiblity of harnessing this energy for practical applications?

 

[Nasor]

I always get the feeling that I'm missing something when people talk about zero-point energy. Zero-point energy, as I recall from my physical chemistry class, is the vibrational energy that remains in a system at absolute zero. That's why it's called 'zero-point'. At the time it seemed to be little more than a mathamatical curiosity because the zero-point energy can never be tapped for anything usefull, since at absolute zero you had already extracted all the vibrational energy that can ever be extracted.

Yet I see people talking about zero-point energy as if it were some sort of mystical energy field. What gives? Am I missing something, or are these people just kooks?

Hey, this is post 1000! fireworks

 

[ScRaMbLe]

I'm not trying to prove anyone right or wrong, just trying to understand for myself. If I am speaking in kookish I would appreciate someone setting me straight in the next couple of days as I'm going away and wont have access to the net for a couple of weeks. Cheers.

 

[ScRaMbLe]

If the universe is infinite in size, then current findings suggest that the amoung of energy is indeed unlimited, since there is energy bound up in the fabric of space itself.

Just to clarify, this is the energy I am refering to when I say "zero point energy" If this is wrong and it has another name, please replace "zero point energy" with the correct name in my above question which is written in red

 

[lethe]

Originally posted by ScRaMbLe
Just to clarify, this is the energy I am refering to when I say "zero point energy" If this is wrong and it has another name, please replace "zero point energy" with the correct name in my above question which is written in red

who is that a quote of?

anyhow, that is, in my opinion, an accurate description of what the zero point energy is.

or like Nasor says: energy that you would have at "absolute zero" (only it wouldn t be absolute zero, since there is energy)

it is also called vacuum energy.

it has nothing to do with ether.

its existence is not a matter of debate. it was settled in the 50s when Casimir measured it. it is real, it exists.

I cannot speak for other members of the board, but i certainly do not remember changing my mind about this issue.

so just to be clear: the zero point energy is real. but devices that can harness that energy are not. to turn that energy into useful energy would violate at least two laws of thermodynamics.

 

[ScRaMbLe]

The quote is James R

it is also called vacuum energy.

Yes! that it the energy I'm talking about (hooray)

Forget aether (ether)...either.

I considered the two different spelt words as two different things, one disproved (ether), the other being a current colloquial term for the fabric of space/time in my understanding (aether). Forget this.

My questions pertain to vacuum energy. I think people such as myself (but not just myself) confuse the terms which has made me think more informed people (such as yourself) have been denying the existance of vacuum energy, when in reality y'all were denying the existance of the archaic ether (not aether).

anyway...

so just to be clear: the zero point energy is real. but devices that can harness that energy are not. to turn that energy into useful energy would violate at least two laws of thermodynamics.

This quote above is the question which I wanted answered all along. Can u explain why harnessing this vacuum energy violates thermodynamics if the energy is indeed unlimited as James says...

Aaiight?!!!

 

[lethe]

Originally posted by ScRaMbLe


My questions pertain to vacuum energy. I think people such as myself (but not just myself) confuse the terms which has made me think more informed people (such as yourself) have been denying the existance of vacuum energy, when in reality y'all were denying the existance of the archaic ether (not aether).

as far as I am aware, ether and æther and aether are all the same word, and they all mean the medium through which electromagnetic radiation passes.

why do you think that there are different kinds of ether?

This quote above is the question which I wanted answered all along. Can u explain why harnessing this vacuum energy violates thermodynamics if the energy is indeed unlimited as James says...

Aaiight?!!!

it violates the second law because even though there is energy there, it is completely thermal. there is no free energy. it violates the zeroth law because since this energy is found at the lowest temperature, you would have to have a heat reservoir at absolute zero to get work from it, and this is not possible.

 

[2inquisitive]

by Lethe:

"it violates the second law because even though there is energy there, it is completely thermal. there is no free energy . it violates the zeroth law because since this energy is found at the lowest temperature, you would have to have a heat reservoir at absolute zero to get work from it, and this is not possible."
============================================

Lethe, could you explain the Casimir effect for me? I know what it
is, I would like to know the mechanisms that create it. Thanks.

 

[lethe]

the vacuum energy is finite for a region of finite size, like a box (excluding modes that cannot see the walls of the box). this energy is calculable, and depends on the size of the box. since the energy depends on the size of the box, and force is the derivative of energy, there is a force on the walls of the box.

this experiment was done, the force was measured, and it agreed with the theoretically predicted result.

 

[ScRaMbLe]

why do you think that there are different kinds of ether?

Hell, I dunno, I picked it up somewhere... Sorry for the confusion it has caused!

I understand what you're saying by having to have a heat reservoir that is colder than where you want to get the heat from. But what if you used a "time reversed" reaction which displayed negetive entropy? Denis Evans from the university of Australia has proven that these reactions can occur in microscopic form for periods up to two seconds.

http://news.bbc.co.uk/1/hi/sci/tech/2135779.stm

Wouldn't this, in theory at least, allow for the collection of this energy?

 

[lethe]

Originally posted by ScRaMbLe
Hell, I dunno, I picked it up somewhere... Sorry for the confusion it has caused!

I understand what you're saying by having to have a heat reservoir that is colder than where you want to get the heat from. But what if you used a "time reversed" reaction which displayed negetive entropy? Denis Evans from the university of Australia has proven that these reactions can occur in microscopic form for periods up to two seconds.

http://news.bbc.co.uk/1/hi/sci/tech/2135779.stm

Wouldn't this, in theory at least, allow for the collection of this energy?

violations of the second law are possible on a microscopic scale, but on larger scales, they always disappear.

now, figure out how to violate the zeroth law, and you will be able to get energy from the vacuum and even keep it for 10^-19 seconds.

 

[ScRaMbLe]

now, figure out how to violate the zeroth law

You know I'd give it a shot if I understood it!

Can u explain the zeroth law, until this thread, I must admit I'd never heard of it.

and you will be able to get energy from the vacuum and even keep it for 10^-19 seconds.

Where does the figure 10^-19 come from?

 

[Stryder]

I always wondered if it was actually the universal background that was measured, or just resonant energy pulled from the molecular array of the container edges of the equipment used to make the vacuum.

 

[James R]

There is some confusion about the term "zero point energy", since it is used in both a general sense and in a specific sense in physics. The general sense is the energy of the lowest energy state of a quantum system. The specific sense refers to the "residual" energy of the vacuum.

Most references to ZPE to be found on the web refer to the vacuum energy. Vacuum energy can be thought of as a result of the Heisenberg uncertainty principle, which says that if you measure the amount of energy in a space for a particular amount of time, you will only be able to determine the energy to a particular degree of accuracy. In practice, this allows for fluctuations of the vacuum, in which the vacuum energy can go from zero to something much higher over very short time scales, after which it drops back to zero again. (This is only a rough explanation, since this is a quantum phenomenon and tied to measurement.)

According to E=mc², when you have enough energy, matter can be created from the energy. This has led to the idea that even in "empty" space, there are constantly particles being created due to fluctuations of the vacuum energy. However, these particles are "virtual", in that they exist only for a very short time. The more massive the particles, the less time they can exist.

During the time the particles exist, they can exert forces on real objects. This leads to forces which have actually been observed, such as the Casimir effect. This is how we know that ZPE of the vacuum is real.

Physicists currently see no way to harness the ZPE of the vacuum, since in a sense it is "borrowed" from nowhere, and must be paid back. However, this does not absolutely rule out the possibility that such a method might be found in the future. Of course, crackpots have jumped on this possibility, claiming to have produced actual machines which harness the ZPE. None of these claims has ever held up under any kind of scientific scrutiny.

So, to summarise, ZPE is a very real, physical phenomenon. Harnessing it <b>may</b> be possible, but nobody has worked out how it might be done yet.

Hope this helps.

 

[ScRaMbLe]

Hope this helps.

Very much so! Thankyou James and Lethe for taking the time to explain. It is appreciated.

Perhaps there is still some hope for the future.

 

[2inquisitive]

Yes, thank you so much, James R. I was having trouble understanding
the concept of ZPE mostly because I wasn't aware of the two
definitions and had read parts of both. That was the basis of my
question to Lethe. And no, I don't believe "Zero Point Energy
Machines" exist. Your post clears things up enormously for me. I
am just very interested in trying to understand a little more in
science.

 

[kazakhan]

Physicists currently see no way to harness the ZPE of the vacuum, since in a sense it is "borrowed" from nowhere, and must be paid back.

Nowhere? Is it only the left over energy that's "paid back"? Wouldn't they lose some energy during the following?

During the time the particles exist, they can exert forces on real objects. This leads to forces ...

Could these virtual particles be due to the bending of space?

 

[Crisp]

Originally posted by ScRaMbLe
I understand what you're saying by having to have a heat reservoir that is colder than where you want to get the heat from. But what if you used a "time reversed" reaction which displayed negetive entropy? Denis Evans from the university of Australia has proven that these reactions can occur in microscopic form for periods up to two seconds.

http://news.bbc.co.uk/1/hi/sci/tech/2135779.stm

Wouldn't this, in theory at least, allow for the collection of this energy?

Sorry to drop in this late, but I would not trust the Evans result that much (about the violation of the second law). There are many, many reasons to believe the experiment is flawed, and that they actually measured the wrong quantity.

See <A HREF="http://arxiv.org/abs/cond-mat/0207587">here</A> and <A HREF="http://arxiv.org/abs/cond-mat/0208154">here</A> (warning: high tech ahead).

Unfortunately, the comments did not make the news as much as the original experiment...

Bye!

Crisp