Zero-point energy - a question for you all.

[NoTime]

The mechanism is analogous to the real Casimir effect, but this acoustic experiment has nothing whatever to do with the quantum vacuum; it concerns sound waves in the air.

The original question seems, at least to me, to be more concerned with the mechanisim of attraction.

I have seen claims that the attraction between the plates is the result of van der wal forces, rather than ZPE.
So what is the status of that argument?

 

[da_willem]

Van der Waals forces are due to momentarily induces dipole moments between neutral molecules, and can shown to be proportional to 1/r^7. The Casimir force theoretically and experimentally obeys an 1/r^4 law. So it's not really an argument...

 

[Asphalt Admiral]

Uneducated newbie

Ok here goes.. I thought I would post even with the fear of being ridiculed for being stupid, so in a preemptive move I should tell you a bit about myself so you can understand my lack of understanding... I didn't graduate h.s. (have a GED) I really became interested in physics within the last 4 or 5 yrs. Quantum physics has excited me in the last couple years due to a couple of friends and I discuss these subjects when we get together.

Tau Muon Planeteater you said (sorry if I am taking this out of context, but it caught my attention) "black hole radiates the same amount of energy as it absorbs." wouldn't this be the same as the law (or rule or whatever) that states "For every action there is an equal and opposite reaction"? or am I off base here??

Also am I correct in assuming that energy cannot be consumed only converted to another kind of energy?

Again sorry for the lack of intelligence here but that's why I am here..

Asphalt Admiral
HMMMMM physics is so kewl!

 

[selfAdjoint]

The black thing that radiates the same as it absorbs is a black BODY, a theoretical object in thermodynamics (well approximated by certain experimental setups). The idea is that most bodies skew their radiation due to atomic or other details of their makeup. But the ideal radiater whose radiation only depends on its temperature would also (it can be proved) be a perfect absorber, hence "black". Black HOLES are something else.

Asphalt, you are correct about energy. It changes form but the total amount of it remains constant. This is called the first law of thermodynamics: Conservation of Energy.

 

[NoTime]

Tau Muon Planeteater you said (sorry if I am taking this out of context, but it caught my attention) "black hole radiates the same amount of energy as it absorbs." wouldn't this be the same as the law (or rule or whatever) that states "For every action there is an equal and opposite reaction"? or am I off base here??

Also am I correct in assuming that energy cannot be consumed only converted to another kind of energy?

Well first that radiates the same amount of energy as it absorbs is taken over the lifespan of the universe. A very long time indeed
It will not complete until long after all the stars have burned out.

There is quite a bit of contention as well as some recent developments related to this.
In some sense information is equated to energy and a black hole is generally thought to destroy information. The energy associated with information has been thought to be non recoverable. This would make the radiate part false.
In the last month or so Hawking has come up with some new ideas related to this so that, as I understand it, the destruction of the energy of information problem goes away.

The "For every action there is an equal and opposite reaction" doesn't really apply here, however, the "energy cannot be consumed only converted to another kind of energy" is quite to the point. The entire thing seems to be about if this is true or false.

This is my understanding of this, hopefully I have the basic idea correct.

 

[NoTime]

Van der Waals forces are due to momentarily induces dipole moments between neutral molecules, and can shown to be proportional to 1/r^7. The Casimir force theoretically and experimentally obeys an 1/r^4 law. So it's not really an argument...

Thanks, my information is out of date.

 

[Larry717]

Energy in the Quantum Vacuum

On Sci.physics, thread free energy devices and technology,
10/7/04, Robert E. McElwaine, (BS physics), wrote:

Free Energy Inventions are devices which can tap a
seemingly UNLIMITED supply of energy from the universe, or
from hyper-dimensional sources, with-OUT burning any kind of
fuel, making them the PERFECT SOLUTION to the world-wide
energy crisis and its associated pollution, degradation, and
depletion of the environment.

McElwaine lists a number of devices that he claims can
deliver on the promises above. But is this just wishful thinking
or is there any substance to his claim?

Here is a quotation from the journal New Scientist (1991). Is
the situation described by Dr. Wesson still true today?

According to quantum theory, a vacuum contains energy.
According to relativity theory, this 'zero point energy' must
have a gravitational effect, influencing the Universe at large.
However, these two requirements are irreconcilable, according
to Paul Wesson of the University of California, Berkeley. He
says that if the zero point energy really exists, 'major revisions
may be necessary in quantum mechanics and/or gravitation'.

--------
Larry

 

[selfAdjoint]

Lots of people, not all of them capable, have been pursuing the ZPE dream. Nothing REAL has come of it. ZPE energy does not seem to be usable; the only known wy to tap it is the Casimir effect, and that provides amounts so small only special purpose lab sensors can detect it, and then only after fantastically delicate lab preparations. Don't believe what you read on sci.physics; go to the monitored site sci.physics.research.

 

[juju]

Hi all,

There is today much theoretical and practical work being done on zero-point energy. (ZPE).

Some have related the ZPE to mass, inertia and gravity.
(Puthoff, Haisch, and Rueda)

Others have related it to dark energy and dark matter. (Jack Sarfatti)

There are many projects going on whose goal is to tap this energy.

I hope they succeed.

As to the point about monitored vs unmonitored sites, it al comes down to the opinion of the monitor what gets on. Sometimes they have their heads you know where.

juju

 

[Larry717]

Second Question

SelfAdjoint,

Please respond to Paul Wesson's conclusion below.
-----------------------------------------------------------
Here is a quotation from the journal New Scientist (1991). Is
the situation described by Dr. Wesson still true today?

According to quantum theory, a vacuum contains energy.
According to relativity theory, this 'zero point energy' must
have a gravitational effect, influencing the Universe at large.

However, these two requirements are irreconcilable, according
to Paul Wesson of the University of California, Berkeley. He
says that if the zero point energy really exists, 'major revisions
may be necessary in quantum mechanics and/or gravitation'.
--------
Larry

 

[selfAdjoint]

Hi all,

There is today much theoretical and practical work being done on zero-point energy. (ZPE).

Some have related the ZPE to mass, inertia and gravity.
(Puthoff, Haisch, and Rueda)

Others have related it to dark energy and dark matter. (Jack Sarfatti)

There are many projects going on whose goal is to tap this energy.

I hope they succeed.

As to the point about monitored vs unmonitored sites, it al comes down to the opinion of the monitor what gets on. Sometimes they have their heads you know where.

juju

Sarfatti is a crank. His only virtue is that he has refuted Puthoff, who is just barely not a crank. There is nothing useful for anybody in their work.

 

[selfAdjoint]

SelfAdjoint,

Please respond to Paul Wesson's conclusion below.
-----------------------------------------------------------
Here is a quotation from the journal New Scientist (1991). Is
the situation described by Dr. Wesson still true today?

According to quantum theory, a vacuum contains energy.
According to relativity theory, this 'zero point energy' must
have a gravitational effect, influencing the Universe at large.

However, these two requirements are irreconcilable, according
to Paul Wesson of the University of California, Berkeley. He
says that if the zero point energy really exists, 'major revisions
may be necessary in quantum mechanics and/or gravitation'.
--------
Larry

How much energy is there in ZPE? It could be much, it could be zero. Notice the big IF in Wesson's statement.

 

[juju]

Sarfatti is a crank. His only virtue is that he has refuted Puthoff, who is just barely not a crank. There is nothing useful for anybody in their work.

You say this because you have a point of view which is not consistent with theirs. You have to protect your mainstream physics realm. I do not have this problem. My point of view is open. It appears yours is not. Even Andrei Sakaroff had some ideas similar to those you call cranks.

Do you know anything about the work (both theoretical and practical) that is being done on overunity and anti-gravity devices. It appears not.

The conflict between Puthoff and Sarfatti is good. It will advance the field of new physics and maybe leave you behind.

juju

 

[Larry717]

exotic matter and zero point energy

SelfAdjoint,

Thank you for answering my previous questions. I appreciate your insight.

Now, is there any relationship between exotic matter and zero point energy; I
mean, is exotic matter a manifestation of zpe?

If zpe does not exist, does that necessarily mean that exotic matter doesn't exist either? I realize that exotic matter violates an important energy condition, but does that mean it can not exist?

I don't intend to pursue the subject of zpe any further. Solutions to Einstein's equations predict the existence of wormholes. Do you doubt that exotic matter could exist and/or be created?

Larry

 

[selfAdjoint]

Larry, I don't know what you mean by exotic matter. Could you clarify?

 

[Larry717]

Exotic Matter

Larry, I don't know what you mean by exotic matter. Could you clarify?

According to Kip Thorne (Am. J. Phys., 5/88) a wormhole requires in its
throat a special form of matter, ostensibly to keep it open.

This special matter is called "exotic" because it must have a tension
greater than its energy density. This means some observers near the
throat see a negative mass-energy density. This violates certain
energy conditions.

A situation where quantum fields can have negative energy density,
violating the energy conditions, is a squeezed state of the
electromagnetic field. Kip writes that, just before his article was
published, such a state became a practical reality in the laboratory.

In the squeezed state, a traveling EM wave oscillates back and forth
between positive and negative energy densities, but has positive
time-averaged energy density.

No specific reference was made to zero point energy. But the vacuum
"is defined to have vanishing energy density."

What do you make of this?

Larry

 

[selfAdjoint]

The energy density of the quantum vacuum is unknown. Physicists DEFINE it to be zero in order to make their formulas easy. They could have defined it to be anything, since it can't be measured. Defining it to be zero means that all energies they deal with are positive.

 

[selfAdjoint]

The energy density of the quantum vacuum is unknown. Physicists DEFINE it to be zero in order to make their formulas easy. They could have defined it to be anything, since it can't be measured. Defining it to be zero means that all energies they ordinarily deal with are positive.

 

[Lacy33]

The energy density of the quantum vacuum is unknown. Physicists DEFINE it to be zero in order to make their formulas easy. They could have defined it to be anything, since it can't be measured. Defining it to be zero means that all energies they ordinarily deal with are positive.

Just listening.
Thank you.
S

 

[NoTime]

The energy density of the quantum vacuum is unknown. Physicists DEFINE it to be zero in order to make their formulas easy. They could have defined it to be anything, since it can't be measured. Defining it to be zero means that all energies they deal with are positive.

Last I recall seeing anything about this

Based on the QM oscilator concept and given a guess as to the value of the UV cutoff
somewhere around 10^31 g/cm^3.

What happened to all of that?

 

[avemt1]

Like I said, you cannot extract energy from the Casimir effect. So there isn't any 1st law issue.

wrong read this
http://www.physicspost.com/articles.php?articleId=114&page=1

 

[juju]

Hi,

The ideas about vacuum energy density and its origin are still in flux.

Calculated from dark energy and casmir effect considerations it appears to be rather small.

However, calculated from first principals it appears to be rather large. This discrepancy is still being investigated.

The discrepancy may be due to phase considerations in a wave approach to the problem.

I also remember reading of a discussion between Hawking and Penrose, where the vacuum energy density was considered as an evolution of the Weyl tensor from the time of the big bang.

juju

 

[NoTime]

wrong read this
http://www.physicspost.com/articles.php?articleId=114&page=1

Hmmm. Brownian ratchet molecule on a shaft?

Can't see how that would violate the first law though.
Throw baseballs at a water wheel.
Seems to me that it would work out to much the same thing.

 

[avemt1]

Hmmm. Brownian ratchet molecule on a shaft?

Can't see how that would violate the first law though.
Throw baseballs at a water wheel.
Seems to me that it would work out to much the same thing.

could it be that the casmir effect is present due to the strong cohesive properties of metal? Could cohesive properties be pulling the metal sheets together? Does anyone think we could harvest this energy in any other way than already stated, and what would be the first law?

 

[selfAdjoint]

could it be that the casmir effect is present due to the strong cohesive properties of metal? Could cohesive properties be pulling the metal sheets together? Does anyone think we could harvest this energy in any other way than already stated, and what would be the first law?

No, the experimenters have allowed for those forces. They'd have been pretty dumb if they haven's, because the cohesive forces are well understood.

 

[avemt1]

Well then what would be the forst law that russ_watters was talking about earlier?

 

[da_willem]

The first law of thermodynamics; conservation of energy...

 

[avemt1]

Energy can not be created or destroyed, only converted.
Is that the one?
This would cause a very hard dilema. We might be able to find where the casmir effect originates if the device was ever created, or destroy our veiw of physics all together.

 

[Chronos]

That would be a good one to keep in mind the next time you design a free energy machine. The Casimir effect is a local effect. You can unbalance any force locally. The net energy of the global system is, however, unchanged.

 

[avemt1]

We might be able to find where the casmir effect originates if the device was ever created, or destroy our veiw of physics all together.

That would be a good one to keep in mind the next time you design a free energy machine. The Casimir effect is a local effect. You can unbalance any force locally. The net energy of the global system is, however, unchanged.

If you take energy from an energy system at a local point, such as the casmir effect, shouldn't energy be converted from the system?
Could you then find the place in the system that the energy was taken from, and use equations to find the path of the loss of energy. Almost like you would figure the path of an electrical surge?