Wireless Non-Radiative Energy Transfer = scalar wave transmission

[S Claus]

Hi all,

The description of Wireless Non-Radiative Energy Transfer by Marin
Soljacic et al uses something called 'evanescent fields' to transfer
power. Are these evanescent fields the same as the scalar waves
demonstrated by Jean-Louis Naudin here:
http://jnaudin.free.fr/html/sclxmtr.htm

....and by Konstantin Meyl in the devices and kits available here:
http://www.etzs.de/onlineshop/index.php?

Or are evanescent fields something else, and if so, how are they
related?

Thanks in advance

 

[Edward Green]

Hi all,

The description of Wireless Non-Radiative Energy Transfer by Marin
Soljacic et al uses something called  'evanescent fields' to transfer
power. Are these evanescent fields the same as the scalar waves
demonstrated by Jean-Louis Naudin here:http://jnaudin.free.fr/html/sclxmtr.htm

...and by Konstantin Meyl in the devices and kits available here:http://www.etzs.de/onlineshop/index.php?

Or are evanescent fields something else, and if so, how are they
related?

Thanks in advance

I'm no expert, but magnetic fields can penetrate a Faraday cage, and
thus obviously modulated magnetic fields can also to some extent.
This is a near field non-radiative effect, and seems to correspond to
what Naudin's device is doing, despite his protestations that he is
canceling the magnetic field, and left with a "pure potential".

There seems to be something mystical about the use of electronics, in
that it's possible to build working devices that do _something_, being
skilled in the art, but not necessarily therefore be giving the
correct theoretical explanation for what one is doing -- like an
alchemist.

Just my uninformed two cents.

 

[Edward Green]

Hi all,

The description of Wireless Non-Radiative Energy Transfer by Marin
Soljacic et al uses something called  'evanescent fields' to transfer
power. Are these evanescent fields the same as thescalarwaves
demonstrated by Jean-Louis Naudin here:http://jnaudin.free.fr/html/sclxmtr.htm

...and by Konstantin Meyl in the devices and kits available here:http://www.etzs.de/onlineshop/index.php?

Or are evanescent fields something else, and if so, how are they
related?

On further reading...

http://en.wikipedia.org/wiki/Scalar_field_theory_(pseudoscience)

"Evanescent fields" are part of mainstream EM, "scalar waves" are
not. Probably, again, what is described in your first citation can be
described by a group of standard buzz words, such as "near field
inductive coupling", or, as you mention "evanescent fields"... which
are "evanescent" not in the time domain, if I understand correctly,
but in the spatial domain (misleadingly), which means they are fields
which penetrate what in quantum mechanical terms would be a forbidden
zone, wherein they die out exponentially with distance. The relation
of the two concepts which you ask for would be "mainstream explanation
of observed phenomenon" vs. "proposed alternative explanation in terms
of new science".

It's telling that these supposed scalar waves are also called "Tesla
waves" (loc. cit.): Tesla was of that ilk I spoke of, of great
practical ability in electrical apparatus but also of a mystical tint,
or at least not satisfied with the standard theory; to this day there
is a kind of evanescent residue of his proposals penetrating standard
EM, where it is theoretically forbidden.

There are still a few people around this zoo^H^H^H group who know
something about radio, but I guess they are just too bored to comment,
even for a pleasant pseudoscience debunking fest.

 

[Benj]

There are still a few people around this zoo^H^H^H group who know
something about radio, but I guess they are just too bored to comment,
even for a pleasant pseudoscience debunking fest.

Ok. "evanescent waves' means "waves that die out" ["vanish like
vapor"] Which sort to kills the idea of power transmission, doesn't
it?

And while we are at it take a good look at the Caduceus Coil. Think
about how it's wound for a minute, OK? It's what we in radio land used
to call "a two layer coil". But be very careful because of the
particular shape of this two layer coil, it is very dangerous in that
it can attract physicians and others in the medical community. And as
has been well established, Doctors are MUCH more dangerous than guns!
So take your Caduceus Coil to the next Coil Buyback in your area and
do it for the children!

Have fun, apes ^H^H^H^H guys, but play nice!

 

[Edward Green]

There are still a few people around this zoo^H^H^H group who know
something about radio, but I guess they are just too bored to comment,
even for a pleasant pseudoscience debunking fest.

Ok. "evanescent waves' means "waves that die out" ["vanish like
vapor"] Which sort to kills the idea of power transmission, doesn't
it?

IIRC they die out in space, not time. This allows power transmission,
but limits its range.

 

[Timo A. Nieminen]

On further reading...

http://en.wikipedia.org/wiki/Scalar_field_theory_(pseudoscience)

"Evanescent fields" are part of mainstream EM, "scalar waves" are
not. Probably, again, what is described in your first citation can be
described by a group of standard buzz words, such as "near field
inductive coupling", or, as you mention "evanescent fields"... which
are "evanescent" not in the time domain, if I understand correctly,
but in the spatial domain (misleadingly), which means they are fields
which penetrate what in quantum mechanical terms would be a forbidden
zone, wherein they die out exponentially with distance. The relation
of the two concepts which you ask for would be "mainstream explanation
of observed phenomenon" vs. "proposed alternative explanation in terms
of new science".

It's telling that these supposed scalar waves are also called "Tesla
waves" (loc. cit.): Tesla was of that ilk I spoke of, of great
practical ability in electrical apparatus but also of a mystical tint,
or at least not satisfied with the standard theory; to this day there
is a kind of evanescent residue of his proposals penetrating standard
EM, where it is theoretically forbidden.

There are still a few people around this zoo^H^H^H group who know
something about radio, but I guess they are just too bored to comment,
even for a pleasant pseudoscience debunking fest.

That would take reading the links in order to make an informed comment,
time for which might or might not be available when at computer. (My plan
is to spend some time on some light renovations - re-doing a feature wall
and doing the stereo shelf next to it that I started 7 years ago. The Big
Decision is whether to get new speakers now, and whether to put them
anywhere fancy, like elevated.)

Power transfer by free-space radiation tends to suck as far as efficiency
goes. Using the evanescent field isn't a bad way to go at all, since the
evanescant fields are large compared to the propagating fields in the near
field. So, nice for special cases like water-proof toothbrush chargers.
And, of course, the transformer.

For the transfer of angular momentum, since you get hbar per photon
(classically, power/angular frequency), you want the frequency to be as
low as practical. This means that you are typically in the near field, so
you're using the evanescent field to transport the angular momentum. It
isn't usual to look at electric motors with this view, but it's
fundamentally correct.

 

[Edward Green]

On Sat, 10 Jan 2009, Edward Green wrote:


That would take reading the links in order to make an informed comment,
time for which might or might not be available when at computer.

You are not the only respondent I was thinking of, please don't take
my remark personally or as showing a desire to infringe your time. It
happens that radio was one of the last areas where there was some
residue of practical knowledge amidst the noise In the old
sci.physics, half a dozen not completely ignorant people would have
jumped on this question already, and there would have ensued some
general discussion about wireless transmission of power, which would
have included the schemes of Tesla, the work at MIT, and energy
sucking antennas.

(I seem to be suffering from an outbreak of verbosity, and shall apply
some ointment).

(My plan
is to spend some time on some light renovations - re-doing a feature wall
and doing the stereo shelf next to it that I started 7 years ago. The Big
Decision is whether to get new speakers now, and whether to put them
anywhere fancy, like elevated.)

I had the same pair of speakers for 20 years, blasted them but never
blew them, and although the cases got progressively more beat up, they
sounded good as new. Lost them in some move or other. They were very
"clean", never muddy, and had impressively large woofers. I spent one
year of summer earnings on them after high school, was scolded by a
parent by spending my money that way, but, all in all, they proved to
be an excellent investment.

Power transfer by free-space radiation tends to suck as far as efficiency
goes. Using the evanescent field isn't a bad way to go at all, since the
evanescant fields are large compared to the propagating fields in the near
field. So, nice for special cases like water-proof toothbrush chargers.
And, of course, the transformer.

IIRC, there are some conditions wherein we can do significantly better
than the approximation of transformer coils.

For the transfer of angular momentum, since you get hbar per photon
(classically, power/angular frequency), you want the frequency to be as
low as practical. This means that you are typically in the near field, so
you're using the evanescent field to transport the angular momentum. It
isn't usual to look at electric motors with this view, but it's
fundamentally correct.

Provocative.

 

[Edward Green]

One thing that has definitely limited the life of
many speakers is the use of foam surrounds.  (The
surround is the ring of stuff that attaches the
outer rim of the cone to the frame.)  The foam
disintegrates over time (10-20 yrs) until there is
nothing supporting the rim of the cone.  

You can get kits from places like Parts Express to
replace these, but it requires careful surgery on
your woofers to remove the old surround and glue
the new one in with everything aligned.

The foam surrounds seem to have come into fashion
in the late 70s.  They may have had some acoustic
benefits over the older paper, cloth, or rubber
surrounds, but long life wasn't one of them.  I
have speakers from the mid 70s with butyl rubber
surrounds that are still going strong.

Well, these would have been mid 70's vintage -- damn it all!