The Good, Bad, Ugly: mit waves and handwaving!

[davieddy]

Originally Posted by only_human

When holding 3D glasses against the LCD, in the orientation as they would be worn, the image is bluer (through both lenses) at 45 and 225 degrees and yellower at 135 and 315 degrees.

I hope this can be regarded as a blueish/yellow herring.
OTOH it may be a clue (quarter wave plates etc).
I have a feeling in my water that someone may suggest
lavatory crystals before long.

[only_human]

Originally Posted by davieddy

I hope this can be regarded as a blueish/yellow herring.
OTOH it may be a clue (quarter wave plates etc).
I have a feeling in my water that someone may suggest
lavatory crystals before long.

I feel that the color shift to be interesting and that it is a useful point of attack.

The intensity (saturation?) of these colors is fairly weak but it is still quite obvious that the first blue peak is at pi/4 and the first yellow peak at 3/4 pi.

The first thought I have is to note that these peaks are 90 degrees apart and wonder what that means. I also wonder in what sense these are complementary colors. I thought that blue and yellow were complements on the subtractive primary wheel but I don't know what complementary means on the additive primary wheel because it takes three colors for our eyes to see white.

I have held the glasses against the red LED of my optical mouse and don't notice any effects with glasses in any orientation.

I'm willing to take suggestion for other things to try.

My ideas include tilting the glasses; I note that my LCD monitor is apparently providing both planar and circularly polarized light (which I find interesting too).

I am willing to acquire a cheap laser pen to try; are they are true lasers? Long ago I had a workbench and a Helium Neon laser in my junk pile but now have neither. Recently I discarded a couple true laser printers but would have been reluctant to try using those lasers anyway.

Perhaps a diffraction grating would be useful. I imagine Edmund Scientific has those and maybe my local FRY's store. Perhaps holding up the glasses to diffraction on a CD would be sufficient since I have lots of those.

I've resisted looking on the internet for answers partly so that I would be doing a true experiment without foreknowledge. I intend to allow handwaving and links in this thread and but prefer to not treat them as full proofs because technical ones can be a stumbling block to general thread participation and treating them as definitive truncates discussion without providing understanding (to the mortals that find them to be a bit opaque).

The 3D cinema glasses I am using are branded "REALD." The are distributed in a plastic wrapper that lists the web site: www.REALD.com. As yet I have not looked there.

[xilman]

Originally Posted by davieddy

Paul?

You called?

I think it's something to do with quantum mechanics.

Seriously: I've been on a business trip and haven't yet had chance to think about the situation. Sounds to me very much like a phase retarder, aka polarization rotator, is inserted somewhere in the system. That, for instance, is the standard way of creating unidirectional light beams, such as are found inside a ring laser.


Paul

[only_human]

Originally Posted by xilman

Sounds to me very much like a phase retarder, aka polarization rotator, is inserted somewhere in the system.

I looked at that company and that seems to be the case: 3D Eyewear, Retardation Plates.

Real D: The Future of Cinema

there are numerous areas where seeing in 3-D can be vital, which inexorably led to the development of technology. One of the most significant companies involved was StereoGraphics, which Real D acquired three or four years ago to provide their base technology.

"From that point," Greer says, "we then spent another three years refining the technology further, bringing in a lot more advanced optics, a whole new generation of digital projectors, and completely refined the system again, to really make it at the quality we have today."

Importantly, they also refined the system to the point where it could be displayed on a single projector. Greer laughs as he tells us that "it seemed in concept a really simple idea, but it took us a hell of a lot longer than we ever imagined to actually make it work and work well."

This helps make the system cost-effective to install, which is obviously a hugely important concern for any new technology. In fact, as Greer told us; "All of our technology is designed to sit off of what is becoming the digital cinema standard. So, currently all of our systems run on DLP based projectors. There are three vendors that produce that, as well as about 10 different servers that are produced. So you need to have that base projector and server."

That's far from the end of the story though, with "a number of pieces of technology, both hardware and software, optical and digital" also factored in as part of the Real D system. There's the specially formulated silver screen, which, while not new tech in and of itself, is the result of "an incredible amount of time and energy working with the vendors to re-engineer that for the quality we have today." There's an optical device called the Z-Screen that sits in front of the lens of the projector. It acts as "a special liquid crystal modulator that polarizes the light, the left eye and right eye information, in opposite circular states." And then there's the eyewear. Forget the ancient red and blue though, as Real D uses "a specially polarized type of eyewear called circular polarized lens, which is very different from traditional 3-D in that it allows you to tip your head without losing the 3-D effect — something you can't do with typical 3-D systems." Then there's "a series of hardware and software drive modules that do our electronic noise reduction and synchronize the projector, and actually help juice the projector — we actually run them at 144 frames a second." Phew.

In other words, this system is based on technology that's been around for 20 years, refined to within an inch of its life, and the results speak for themselves, all without the (literal) headaches of the older systems.

REAL D - Patent Department

I'm curious, why does it matters which way the glasses are facing?

Added:
It looks like they might succeed as a business venture. They have about 10 3D films for release this year; tomorrow my girlfriend wants me to take her to the opening of "Up" in 3D.

Are there any experiments anyone wishes me to try in the movie theater? Some possibilities that occur to me are bringing a 2nd pair of the glasses and trying different orientations of one or both pairs -- I also have a pair of clip on planar polarized sunglasses.

[davieddy]

Who was first to respond to the "Many Universes" interpretation of QM with
"Cheap on hypothesis. Expensive on universes"?

David

PS "I'm interested in the universe and all that surrounds it" (Peter Cook)

[frmky]

The RealD glasses have a quarter wave plate on the front surface (the side facing the screen) and a linear polarizer on the back surface. Therefore, when you place the sunglasses behind the RealD glasses, it's acting just as two linear polarizing filters would. When they are in the front tho, the quarter wave plate turns the linearly polarized light into circular polarized light, when then goes through the back linear polarizer.

When light shines from the front, the lens acts as a circular polarizing filter. When the light shines from the back, it acts as a circular polarizer. Therefore, when you hold opposite lenses front to front, the light will be blocked in all orientations. Actually, since they are made cheaply, not all light is blocked, but most of it is.

[only_human]

Originally Posted by frmky

When light shines from the front, the lens acts as a circular polarizing filter. When the light shines from the back, it acts as a circular polarizer. Therefore, when you hold opposite lenses front to front, the light will be blocked in all orientations. Actually, since they are made cheaply, not all light is blocked, but most of it is.

Ok, this makes sense to me and the rest I will dwell on until I understand. I'm actually amazed how well they block light for an item handed out for a movie that has a $1 to $5 premium over the cost of the non 3D movie. It is beautiful to move a clear surface past another and see it look so opaque (it certainly seems to block more than the last time I tried two sunglasses at right angles)

ColorLink, owned by RealD, has a patent (7,106,509) on a fancy kind of sunglasses:

ColorCorrect® consists of a retarder film based filter that is sandwiched between two polarizers. One version is a triple bandpass filter that only allows the transmission of the three colors – red, green, and blue – which enhances color and contrast. ColorCorrect is ideally suited for improving vision in sports eyewear, sunglasses and ski goggles especially in low light and flat light conditions. The filter can be designed to enhance specific regions of the visible spectrum to improve vision performance for specific sports such as tennis, baseball, golf, etc. The ability to see for example a yellow tennis ball when tossed in the air or a white baseball on a cloudy day is dramatically improved by wearing ColorCorrect sunglasses.

[only_human]

Originally Posted by davieddy

Who was first to respond to the "Many Universes" interpretation of QM with
"Cheap on hypothesis. Expensive on universes"?

David

PS "I'm interested in the universe and all that surrounds it" (Peter Cook)

Google tells me that it was Paul Davies, at least according to page 209 of this book (isbn=0393323102):

Quantum Evolution: How Physics' Weirdest Theory Explains Life's Biggest Mystery - Google Books Result by Johnjoe McFadden - 2002 - Science - 338 pages
The physicist Paul Davies commented that the Many Worlds interpretation is 'cheap on assumptions but expensive on universes. ...

"cheap on assumptions but expensive on universes"

[davieddy]

Originally Posted by davieddy

I hope this can be regarded as a blueish/yellow herring.
OTOH it may be a clue (quarter wave plates etc).

http://hyperphysics.phy-astr.gsu.edu...pt/quarwv.html

The colour effect will be down to variation of refractive index
over the visible spectrum (dispersion).
The phase shift is only precisely pi/2 (quarter wave) for green
light.

[only_human]

Originally Posted by davieddy

http://hyperphysics.phy-astr.gsu.edu...pt/quarwv.html

The colour effect will be down to variation of refractive index
over the visible spectrum (dispersion).
The phase shift is only precisely pi/2 (quarter wave) for green
light.

Thanks. I played around with a pair of glasses during the 3D movie "Up" and noticed that when I held them backwards I saw blueing at 0 degrees and yellowing at 90 degrees (or the other way around. not sure). That is 45 degrees off from my LCD display so it will give me something to think about while I read up on Quarter-wave plates.

I didn't intend to have exclusive use of this thread and formally yield it further to those who wish to use it to talk about science or maths (good, bad, ugly mit waves und handwaving!) with the crank ratings available for reference for those who wave so hard that they bruise themselves while patting their own backs.

As for "cheap on assumptions but expensive on universes," I found the original quote, I think, in:
The ghost in the atom
By P. C. W. Davies, Julian Russell Brown, page 84
The ghost in the atom: a discussion of the mysteries of quantum ... - Google Books Result
by P. C. W. Davies, Julian Russell Brown - 1993 - Science - 169 pages
Paul Davies, I believe, said it during a interview with David Deutsch.

Now the other interpretations of quantum theory also involve rather counter-intuitive assumptions about reality. In some of them consciousness - human consciousness - has a direct bearing on the nather of physical reality, so that nothing exists until it is observed. This is, in my view, a far more spectacular and actually unacceptable consequence of the theory than the idea of parallel universes.

So the parallel universes are cheap on assumptions but expensive on universes.

Exactly right. In physics we always try to make things cheap on assumptions.

[davieddy]

Originally Posted by only_human

Thanks. with the crank ratings available for reference for those who wave so hard that they bruise themselves while patting their own backs.

You talking to me????
I don't see anyone else around