light wave phase cancellation

dCastillo · May 2005

think about it sometime

drewnice · May 2005

Sketch is on some other, other, other, other...

Bambouche · May 2005

(the missing fundamental)

psychoacoustics.

removing the fundamental.

enhances the harmonic.

psychoacoustics.

fletcher munson motherfucking lied to you

listen

your mp3s are stealing your fundamentals

listen

dCastillo · May 2005

yes.
now you want to bring sound into it.
it's funny that you post this, because producers, when sampling, tend to want to isolate the elements in a layered sample, and keep only the fundamental frequencies. If they were to 'enhance the harmonic', the other elements they don't (think they) want will be more prevalent. this is what your mind tells you makes sense, when in fact, it will sound better going against your mind, and letting your ears perceive things. enhance those harmonics, boost up those other elements. making something that you're not expecting is fun anyway, and hearing pro results is even better. it's like painting what you think you see, instead of looking at what you see scientifically--seeing it for what it is--how light is really effecting the color and all of that. you will suprise yourself. pho sho.

but let's get back to lightwave phase cancellation. I believe that psychoacoustics will be an obstacle to overcome when formulating this invention. I don't think it will stop the project dead in it's tracks. The biggest problem I see is 'predicting' the light waves before they reach the device, but then again this will only be a problem for objects in motion. The objects that are in a constant position and lighting should be easy to deal with. Hell, it might only work in these circumstances, since nothing can move faster than the speed of light--it can only get closer and closer. You can divide forever. You will never hit zero.

Jonny_Paycheck · May 2005

I just want to know how to get styrene hiss out of this loop, loopa.

dCastillo · May 2005

raise the hiss.
enhance its harmonic

Jonny_Paycheck · May 2005

interesting. I will try this. The sound of the zeekers.

z_illa · May 2005

If they were to 'enhance the harmonic', the other elements they don't (think they) want will be more prevalent. this is what your mind tells you makes sense, when in fact, it will sound better going against your mind, and letting your ears perceive things. enhance those harmonics, boost up those other elements.

stop giving away my secrets. you are violatin.

and when it comes to light, in the real world waves travel in a non linear fashion. Complete cancellation would be impossible, only subtraction. Sound cancellation comes into play only when ambient waves are caputured to be processed, then rereleased. So Mr. Castillo, my question for you is: What is the medium for your invention? If you are trying to work with live waves, not "images" of waves I have a hard time believing true cancellation can occur. I guess this goes back to your objects in motion comment, but I would assume two fixed points in a vacuum would be required for significant subtraction (cancellation). yao?

Bambouche · May 2005

yes.
now you want to bring sound into it.

Listen, poptart! Why do you insist on making this about anything but sound?

[color:pink](It's cool man, I am just actin' hard for those dudes lurking from the other board who say we're intimidating.) [/color]

So, you're talking about "lightwave" and I'm on some "light wave." Like dudes who say, "Why does this all sound weird?" when their speakers are 90degrees out of phase. Hence, Light Wave Phase Cancellation[/b] as opposed to Big Dude Wave Phase Cancellation???[/b]

If I may bring the point to your area code. In the '80s, a punk engineer working a session at Chicago Recording Company pointed out their speakers were out of phase. (File Under: Supposed Big Dudes Not Reading Their Oscilloscope)

dCastillo · May 2005

go deaf by silence.

think about that sometime.

z_illa · May 2005

Phase Conjugation

Phase conjugation is an operation that can be performed on waves, so that they reflect back, like a retroreflector, but with some unusual properties. This technique uses a special kind of "mirror" to generate what is called a conjugate reflection of an incoming wave.

The simplest wave (monochromatic or single-frequency) is known as a sine wave. A sine wave can be thought of as a repetitive, circular motion "turned on edge" and drawn out across an area of space.

As a wave moves along in space and in time, we can chart that movement, on a graph, in terms of its angular phase displacement in degrees around a 360 degree circle, from an agreed-upon starting reference point. Thus we can talk about "phase angles" when we mean "wave travel" and/or "time elapsed" with respect to our starting "zero-phase" reference.

Viewed on an X-Y graph, the conjugate of a positive angle, 45 degrees for example, is found by reversing the sign of the angle: i.e., minus 45 degrees. Thus the positive angle in the first quadrant of the X-Y graph moves down into the 4th quadrant. (Remember the plastic protractor you used in high school math? It spanned the first 2 quadrants, from 0 to 180 degrees, a half-circle.)

Notice that if we increase an angle from 0 to 45 degrees on our graph, we are opening up the angle in a counterclockwise direction on the graph. Starting at 0 and opening an angle to -45 (the conjugate of +45), moves the angle arrow in the opposite direction, clockwise. Algebraically, an angle added to its conjugate sums to zero.

The 2-dimensional phase conjugate plane wave, then, is essentially a reversed version of the original wave-- the wave is at the same phase and shape, traveling in the same path as the incoming wave, but in exactly the opposite direction.

The phase difference between any two points of the reversed wave has a sign opposite to that of the phase difference between the same points on the original wave. (I specify 2-D plane waves here because that's how we usually think of EM waves; the implications of this with regard to 3-D waves-specifically circularly polarized waves--are worthy of another paper, as they may take some of the ambiguity out of the exact meaning of phase conjugate waves vs. phase inverted waves, since direction of phasor rotation may play a part, and this distinction becomes ambiguous in 2 dimensions).

Because of the phase conjugate wave's property of direction- and path reversal, we will find that, if the source of the incoming (slightly diverging) light is a narrow laser beam, the phase conjugate reflection wave will return to the source by precisely retracing its path back down that beam.

That may sound exactly like retroreflection. However, it is actually more like a "time-reversed", as opposed to merely a "path-reversed" version of the original wave, reconstructing the light's phase and amplitude. Because of the way the phase-conjugate reflection wave precisely retraces the path of the original wave, it automatically compensates for things that happened to the laser beam on its trip from the laser out into the distance, which the retroreflected wave cannot do.

For example, light diverging out from a source may experience distortions; the phase conjugate wave experiences the same distortions, but in the opposite direction and sequence, as if it were going backward in time. Thus the spreadout, distorted light in the phase conjugate beam re-converges in focus on the light source.

Physicists involved in nonlinear optics, the field in which the phenomenon was evidently first discovered, call this the Distortion Correction Theorem. What is still somewhat controversial is whether the effect is actually a "time reversal" of the wave in the truest sense, or just a special sort of "length-" and "path-reversal."

discuss.

funksnotdead · May 2005

i'm gonna be phase conjugating some acappellas out of my instrumental/vocal 12"s

dCastillo · May 2005

i'm gonna be phase conjugating some acappellas out of my instrumental/vocal 12"s

good IDEA

street_muzik · May 2005

I think light wave phase cancellation may already be happening, constantly, around us. Could be what keeps us from seeing the real deal. I mean, what's really going on. Most anyway. Some got the SHINING, light wave phase cancellation style.

dollar_bin · May 2005

think about it sometime

Experience it, this is the sort of thing that allows us to produce holographs.

Index Key: PHY092
Author: kolin
Subject: How do holograms work?

Response #: 1 of 1
Author: Arthur Smith
Text: Most of the time we can ignore the wave nature of light, since it
basically travels in straight lines and obeys simple laws when passing through
lenses or with mirrors. However, when light is specially prepared (as in a
laser) the wave nature can be readily seen - for example, laser light passed
through a pair of slits will produce an "interference" pattern of alternating
dark and light areas as long as the slits are close enough together, and this
is very different from the straight line images you might expect. A hologram
is made by "interfering" in this sort of fashion, laser light that has been
reflected from a 3-dimensional object with light directly from the laser, or
reflected from a flat mirror. Because of the different distances traveled by
the light striking different parts of the object, the light waves arrive at
different parts of their cycle and combine or cancel out. This produces a
very complicated image, which can be recorded on film as a hologram, and
played back to produce something resembling the original 3-dimensional image
(played back by shining laser light through it in the other direction). The
details are pretty complicated, and I have always been amazed that it actually
works. People can now produce these interference patterns on the computer,
and generate a hologram that can be used to produce three-- dimensional images
that were designed on the computer.

Sun_Fortune · May 2005

go deaf by silence.

think about that sometime.

I'm converting my studio into an anechoic chamber.
This silence is deafening!
Can you here me talking over this silence?!
You. What are YOU doing here?
I told you never to come back here. I told you to stay away.
Don't move a foot closer. Argh! Get your hands off me! Argh! HELP!!!

"Ew, this part's disgusting." Jenny took the romote control and fastfowarded.
"Hey Jenny, what the hell? That's the best part." Howard slid off the bed and trotted towards the TV. "I'm overriding you, Jenny."
"Hey, stop it."
"I'll stop if you'll snuggle with me," Howard responded.

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light wave phase cancellation

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