Physics - Negative Frequencies Get Real

[Sam Wormley]

http://physics.aps.org/articles/v5/68

> A soliton is a localized “lump” of light that is the product of wave effects in a nonlinear medium and can, under certain conditions, emit low-intensity, positive frequency resonant radiation in its wake, due to the phase matching between its momentum and the dispersion of the medium itself. Writing in Physical Review Letters, Eleonora Rubino at the University of Insubria in Como, Italy, and collaborators have discovered that there should be a negative frequency counterpart of this resonant emission, which they have identified experimentally in two different systems [1].

[Jan Panteltje]

On a sunny day (Mon, 18 Jun 2012 21:46:23 -0500) it happened Sam Wormley
<swor...@gmail.com> wrote in <CqGdnRTi6o9iekLS...@mchsi.com>:

Negative frequencies are a common thing in electr0nics (folded sidebands).
Now these geniuses have found that is also works for frequencies
as high as those of light,
Re-invented the wheel.

Universities, kids, kids teachers, post scientific era, end of civlisation,
playing, an other tissue paper,
can no longer go to moon and walk there...
Sambot cannot cut and paste, does not understand what he pastes,
hey, ah yes global warming.

[bjacoby]

On 6/19/2012 4:40 AM, Jan Panteltje wrote:
> On a sunny day (Mon, 18 Jun 2012 21:46:23 -0500) it happened Sam Wormley
> <swor...@gmail.com> wrote in<CqGdnRTi6o9iekLS...@mchsi.com>:
>
>> http://physics.aps.org/articles/v5/68

> Negative frequencies are a common thing in electr0nics (folded sidebands).
> Now these geniuses have found that is also works for frequencies
> as high as those of light,
> Re-invented the wheel.
>
> Universities, kids, kids teachers, post scientific era, end of civlisation,
> playing, an other tissue paper,
> can no longer go to moon and walk there...
> Sambot cannot cut and paste, does not understand what he pastes,
> hey, ah yes global warming.

From the article:

"It is the usual practice when dealing with the classical Maxwell
equations, to assume that only positive frequencies have an acceptable
physical meaning. When the soliton dispersion (which is basically a
straight line with a slope proportional to its velocity) and the fiber
dispersion (which is a rather complicated curve) are phase matched at
positive frequencies, positive resonant radiation is produced, which is
the one that most people observe in experiments. However, there is no
particular reason why we have to restrict our attention to positive
frequencies only, since any electromagnetic wave is a real field, and
thus it is the sum of a field with positive frequencies and its complex
conjugate field, and therefore possesses negative frequencies."

Are Jan and I the only ones who have noticed that this explanation is
the biggest load of garbage to come out of modern physics "magic" for
some time? There are no "negative frequencies" any more than waves
travel in "nothing at all". It's all idiocy passed off as science.
Negative solutions folded back on baseband or producing aliasing are
STILL real frequencies. There is NO such thing as a "negative
frequency". It's patent nonsense. This is how low modern physics has sunk.

What is it with Euro-scientists? They used to be the envy of the world.

[Yousuf Khan]

What's a negative frequency supposed to be? A frequency travelling
backwards in time?

Yousuf Khan

[Jan Panteltje]

On a sunny day (Tue, 19 Jun 2012 06:16:02 -0400) it happened bjacoby
<bja...@iwaynet.net> wrote in <mjYDr.5988$iI7...@newsfe03.iad>:

It is not just Europe, remember how MIT reinvented Tesla wireless power transfer,
we are still waiting after many years... (it was sold to Boeing IIRC).
Germany is doing pretty good actually, Italy has had some very strange publications
that I suspect are not correct, but not my field.
Netherlands is doing great too.
US is pretty much dead I think ;-), China is going for the top..

[Jan Panteltje]

On a sunny day (Tue, 19 Jun 2012 16:46:45 +0600) it happened Yousuf Khan
<bbb...@spammenot.yahoo.com> wrote in <4fe0...@news.bnb-lp.com>:

Simple example:
You have a carrier at 1 MHz
SUPPOSE you FM modulate it with 700 kHz

FM modulation causes sideband every 700 kHz, so you get spectral components at:

^
etc
1 MHz - 1400 kHz = -400 kHz <------------------ NEGATIVE frequency
1 MHz - 700 kHz = 300 kHz
1 MHz + 700 kHz = 1700 kHz
1 MHz + 1400 kHz = 2100 kHz
etc
V

The -400 kHz appears nicely as 400 kHz in the spectrum, we call this a 'folded sideband'.

amplitude
|
| 300 400 700 1400
| | | | |
|------------------------------------- frequency
W I W W

not to scale...
:-)

'W' are the wanted frequency components,
'I' is the interfering frequency component caused by sideband folding, or the 'negative frequency').

There are many more sidebands in FM, so there are many more negative frequencies generated in this example,
I have showed only the first one for clarity.

It was quite important in video tape recording where a carrier of a few MHz was FM modulated by a video
signal of also a few MHz,
You have to make sure you filter the 'folded sidebands' as those interfere with (are in -) the wanted spectrum.
It is very old hat, and goes for all EM and other waves, basic theory.

More:
http://en.wikipedia.org/wiki/Negative_frequency

Somebody wants to update wikipedia with this?

[Jan Panteltje]

Corrected typo(*) 1400 -> 1700, text was correct.:

>1 MHz - 1400 kHz = -400 kHz <------------------ NEGATIVE frequency
>1 MHz - 700 kHz = 300 kHz
>1 MHz + 700 kHz = 1700 kHz
>1 MHz + 1400 kHz = 2100 kHz
>etc
>V
>
>The -400 kHz appears nicely as 400 kHz in the spectrum, we call this a 'folded sideband'.
>
>amplitude
> |

> | 300 400 700 1700(*)

[Sam Wormley]

On 6/19/12 5:46 AM, Yousuf Khan wrote:

>
> What's a negative frequency supposed to be? A frequency travelling
> backwards in time?
>
> Yousuf Khan

See: http://en.wikipedia.org/wiki/Negative_frequency

> The concept of negative and positive frequency can be as simple as a wheel rotating one way or the other way.[citation needed] A signed value of frequency indicates both the rate and direction of rotation.

[Jan Panteltje]

On a sunny day (Tue, 19 Jun 2012 11:14:59 -0500) it happened Sam Wormley
<swor...@gmail.com> wrote in <gdOdnRcE2rUZOH3S...@mchsi.com>:

The bot does not even read other postings, how could it!

[hanson]

"Yousuf Khan" <bbb...@spammenot.yahoo.com> wrote:

> Sam Wormley wrote:
>> http://physics.aps.org/articles/v5/68
>>> A soliton is a localized “lump” of light that is the product of wave
>>> effects in a nonlinear medium and can, under certain conditions, emit
>>> low-intensity, positive frequency resonant radiation in its wake, due
>>> to the phase matching between its momentum and the dispersion of the
>>> medium itself. Writing in Physical Review Letters, Eleonora Rubino at
>>> the University of Insubria in Como, Italy, and collaborators have
>>> discovered that there should be a negative frequency counterpart of
>>> this resonant emission, which they have identified experimentally in
>>> two different systems [1].
>>

Yousuf Khan wrote:
What's a negative frequency supposed to be?
A frequency travelling backwards in time?
>

hanson wrote:
... ahahahaha... Yossel, your 2 liner is the only good
input so far. The rest of the post on this is issue are
enormous bowls of world salad, useless sidebar
palaver and laments... none of which explains the
__ buzz word__ "Negative frequencies".
>
It maybe "insider shop talk" jargon by folks in that field.
It may simply be a parlance that alludes to -- the rate of
a frequency lowering or decay when compared to the
original one--, but I dunno, and like you, I am waiting for
an explanation.... ahaha...
>
There is a good likelihood that some Schmuckface will
answer and post: __"You must learn!"__ , and says so
because he himself is not capable of explaining it,
since he does not know neither. --- Happens all the time
in s.p. Hilarious!... ahahahaha... ahahahahanson

[Jan Panteltje]

hanson the idiot wrote:

>... ahahahaha... Yossel, your 2 liner is the only good
>input so far. The rest of the post on this is issue are
>enormous bowls of world salad, useless sidebar
>palaver and laments... none of which explains the
>__ buzz word__ "Negative frequencies".

Have I ever stated you are a complete idiot?
I have now.
:-)

[hanson]

... ahahahaha... AHAHAHAHA... ahaha.. ROTFLMAO!
>
"Jan Panteltje" <pNaonSt...@yahoo.com>
in his now geriatric mind-set cranked himself & wrote:

>
> hanson wrote:
>>... ahahahaha... Yossel, your 2 liner is the only good
>>input so far. The rest of the post on this is issue are
>>enormous bowls of world salad, useless sidebar
>>palaver and laments... none of which explains the
>>__ buzz word__ "Negative frequencies".
>>

>>It maybe "insider shop talk" jargon by folks in that field.
>>It may simply be a parlance that alludes to -- the rate of
>>a frequency lowering or decay when compared to the
>>original one--, but I dunno, and like you, I am waiting for
>>an explanation.... ahaha...
>

Schmuckface Pante tip-toes thru the tulips & wrote:
> Have I ever stated you are a complete idiot?
> I have now.
> :-)
>

Earlier, hanson wrote:
There is a good likelihood that some Schmuckface will
answer and post: __"You must learn!"__ , and says so
because he himself is not capable of explaining it,
since he does not know neither. --- Happens all the time
in s.p. Hilarious!... ahahahaha... ahahahahanson
>

hanson wrote:
.... ahahahaha... So, Pante... my prediction was right.
YOU don't know what you were and are talking about.
Hilarious! Thanks for the laughs, though!... ahahahanson.

[bjacoby]

Oh that's right. I forgot that in your world, Sam, things don't have to
make sense or agree with reality. They just have to agree with the way
YOU say they are true.


Here ya go. Negative AND Imaginary frequencies!

Phrased differently, every real sinusoid consists of an equal
contribution of positive and negative frequency components. This is true
of all real signals. When we get to spectrum analysis, we will find that
every real signal contains equal amounts of positive and negative
frequencies, i.e., if $ X(\omega)$ denotes the spectrum of the real
signal $ x(t)$, we will always have $ \vert X(-\omega)\vert = \vert
X(\omega)\vert$.


It's not worth even saying...

[Yousuf Khan]

On 19/06/2012 8:46 AM, Sam Wormley wrote:

I thought I better actually read this article above, before this thread
gets too silly. So it looks like they're talking about light travelling
through a fibre-optic cable or other such medium, not light in a vacuum.
So obviously, since light travels slower through this medium than in a
vacuum, negative frequencies can happen since they wouldn't actually be
travelling backwards in time. It now makes some sense. Okay, so it's
kinda interesting, not really familiar with optics, so I'm not sure what
the practical applications for it are.

One thing interesting they are talking about is a "supercontinuum",
through which the light travels. The supercontinuum manages to take a
very narrow frequency light and turn it into broad range of frequencies,
maybe so broad that it's equivalent to sunlight. It's possible that
sunlight itself is generated through a supercontinuum, as the Sun's own
outer layers might act as the supercontinuum which takes all of that
gamma radiation and turns it into the broad frequency range that we see
on its surface. I think this might be an interesting highly efficient
new use of nuclear power in the future: you take it's generated gamma
rays, and turn them into broader more usable radiation that can do work
for you. This should be at least more efficient than simply using a
nuclear reactor as a glorified water boiler and driving a gas turbine
with it.

Yousuf Khan

[G=EMC^2]

On Jun 19, 6:16 am, bjacoby <bjac...@iwaynet.net> wrote:
> On 6/19/2012 4:40 AM, Jan Panteltje wrote:
>
> > On a sunny day (Mon, 18 Jun 2012 21:46:23 -0500) it happened Sam Wormley

> > <sworml...@gmail.com>  wrote in<CqGdnRTi6o9iekLSnZ2dnUVZ_o-dn...@mchsi.com>:

Sam Can a negative frequency be another of the universe's balancing
acts.Is "up"positive,and "down" negative We have gravity down as a
negative force. I have space inflating as a positive force Concave and
convex space curve geometry of spacetime.

[Sam Wormley]

You are reading too much in to "negative frequency", Herb.

[G=EMC^2]

Sam can string theory have negative vibrations. Loops that vibrate
outer positive ,and inside the torus its negative? Can a string have
a negative measurement if its 10 times shorter than a Planck length?
(ultra short distances) Sam lets think of the universe going in "The
big Crunch" smaller and smaller.Would its end be a point,or a negative
number(infinitely tiny) Is a hole in the fabric of space a negative
curve? Einstein might go with it?? Are there negative force
charges?,and the electron is thus a negative charge? Positron its
positive twin? Yes Sam I'm reading to much into this,but its
fun.TreBert

[Sam Wormley]

On 6/20/12 7:11 AM, G=EMC^2 wrote:

> Sam can string theory have negative vibrations. Loops that vibrate
> outer positive ,and inside the torus its negative? Can a string have
> a negative measurement if its 10 times shorter than a Planck length?
> (ultra short distances) Sam lets think of the universe going in "The
> big Crunch" smaller and smaller.Would its end be a point,or a negative
> number(infinitely tiny) Is a hole in the fabric of space a negative
> curve? Einstein might go with it?? Are there negative force
> charges?,and the electron is thus a negative charge? Positron its
> positive twin? Yes Sam I'm reading to much into this,but its
> fun.TreBert

Herb, you write as is think string theory is science.