Polarized vision

[Pastor]

Originally Posted by wet

I salute your quick thinking

Anybody got a pair of polarized magnetic-filtering goggles yet?

Guess where I found that picture? Bloody Wikipedia just goes to show eh?

[trux]

Well, I already burned once in this thread, so take my opinion with reserves, but I suspect the picture may be actually right, although it is often shown in the other way. Just try putting a board with slits into water - when the slits are vertically, the waves passing through the slits will create as many new wave-generation points as many slits there are and the big waves coming from one side will be reduced through the interfering of the new individual waves on the other side. On the other hand, when you put the slits horizontally, the wave will pass without interfering. The question is how to apply this apparently mechanic model on the light or electro-magnetic waves, where there is actaully no physical surface or particles that we could observe moving.

[wet]

Originally Posted by DeepThought

Not a physicist, but I thought that the closer an object (that has mass) gets to the speed of light its mass increases rather than decreases. I thought that's why it's theoretically impossible to reach the speed of light - because as mass rises it takes more energy to accelerate, and eventually it'll take infinite energy in order to accelerate to the speed of light... Very cool!!

Since we're already explaining/confusing ourselves with physics, let's see what this cool clip raises:
YouTube - Dr Quantum - Double Slit Experiment
(I'm not comfortable with the strict conclusions this flick presents)

I don't grasp the connection between the double slit video, the speed & mass of light, and polarized sunglasses. (The video reminds of music, the principal note and it's accompanying harmonics.)

AFAIK, polarized light reception is light which has the same wavelength and orientation absorbed by the eye, while all other light is blocked or absorbed by the sunglasses. I don't think that would be called quantum physics, just conventional physics.

[wet]

Originally Posted by trux

Well, I already burned once in this thread, so take my opinion with reserves, but I suspect the picture may be actually right, although it is often shown in the other way. Just try putting a board with slits into water - when the slits are vertically, the waves passing through the slits will create as many new wave-generation points as many slits there are and the big waves coming from one side will be reduced through the interfering of the new individual waves on the other side. On the other hand, when you put the slits horizontally, the wave will pass without interfering. The question is how to apply this apparently mechanic model on the light or electro-magnetic waves, where there is actaully no physical surface or particles that we could observe moving.

The double slit experiment doesn't show polarized light does it?

Have we mixed two different phenomena?

1) Polarized light vision capability
2) Electron/photon interference (sound/light wave harmonics)

[sanso]

Originally Posted by wet

I don't grasp the connection between the double slit video, the speed & mass of light, and polarized sunglasses. (The video reminds of music, the principal note and it's accompanying harmonics.)

Actually Pastor asked for that explanation, just because we were going into physics

AFAIK, polarized light reception is light which has the same wavelength and orientation absorbed by the eye, while all other light is blocked or absorbed by the sunglasses. I don't think that would be called quantum physics, just conventional physics.

the wavelength isn't important here, polarized light may come in any number and combination of colours (i.e. wavelengths), for example sunlight is polarized when reflected at a low angle and still has the same colour.

The description of polarized light above in the thread has been quite correct, I think, but feel free to point us to current papers on the topic.

[trux]

Originally Posted by wet

Have we mixed two different phenomena?

I referred to the first picture in this thread (in post #4), that you claimed is incorrect. In contrary, I believe it is correct, and think that the one more commonly shown in polarization articles (with the amplitude of the wave parallel to the slit) is wrong.

[sciencemike]

Originally Posted by trux

I referred to the first picture in this thread (in post #4), that you claimed is incorrect. In contrary, I believe it is correct, and think that the one more commonly shown in polarization articles (with the amplitude of the wave parallel to the slit) is wrong.

Eh its not that its right or wrong. Its neither. The point is its a schematic to show randomly polarized light passing through a narrow slit polarizing filter. Trux is right in that the picture is not INcorrect. Its merely a convention to say that horizontal polarizing lens will result in vertical polarized light. You can only detect this when you put up another filter at some differing angle. Its a figure to help us all see what is going on and as long as we stick to the convention it makes sense. (Anyone want to argue which way electrical current flows?)

The important thing here is that we all realize the two easy ways to polarize light.

1. - Reflection off of a planar surface (snow, water, windshields, etc)
2. - Polarizing lenses

This is why fish have polarizing filters, to effectively enhance objects reflections that are not at 90', thus making them brighter and the rest of the background/bottom reflection darker. Thus providing a definate enhancement for avoiding PREY and finding FOOD. Because although goldfish arent ferocious predators, they are themselves preyed upon.

[wet]

Originally Posted by sanso

Actually Pastor asked for that explanation, just because we were going into physics

the wavelength isn't important here, polarized light may come in any number and combination of colours (i.e. wavelengths), for example sunlight is polarized when reflected at a low angle and still has the same colour.

The description of polarized light above in the thread has been quite correct, I think, but feel free to point us to current papers on the topic.

Ok, there's nothing about the double slit experiment at the wikipedia entry on polarization:
Polarization - Wikipedia, the free encyclopedia

So now, I'll see about the screen orientation...

[sciencemike]

Originally Posted by wet

Ok, there's nothing about the double slit experiment at the wikipedia entry on polarization:
Polarization - Wikipedia, the free encyclopedia

So now, I'll see about the screen orientation...

Polarization and the double slit experiment are not related in the way you are thinking. The slits in Young's experiment are so narrow they are like point sources. Far narrower than the wavelength of light that passes through them. So for our issues there is no relation between polarization and Young's Double slit experiment.

Although later experiments did show that the light passed throught does undergo polarization*. So polarization and the experiment are related in some way.

* - Degree of polarization in Young’s double-slit interference experiment formed by stochastic electromagnetic beams Vol. 24, No. 7/July 2007/J. Opt. Soc. Am. A

[trux]

Originally Posted by sciencemike

Eh its not that its right or wrong. Its neither. The point is its a schematic to show randomly polarized light passing through a narrow slit polarizing filter.

What I meant is wrong with the parallel model is that it tries comparing the photonic or an EM wave to a string passing through a slit and vibrating in it - in such mechanic model, the amplitude of the string oscillation is limited by the dimension of the slit, hence only waves with the same orientation as the list pass through it.

This is not the case at the wire-grid polarizer shown in Pastor's post at the top - the dimensions of the gaps between the wires are actually macroscopic and nowhere even in orders comparable to particle dimensions. Hence an EM wave passing through is not somehow mechanically limited in its oscillation in the direction perpendicular to the wires. It is not the dimension of the slit that limits the oscillation in certain directions. In the case of the wire-grid polarizer shown above, it is the interaction between the EM wave and electrons in the wires that damps the parallel waves (those moving electrons along the wires). The EM wave loses energy in the sense parallel to the wire due to the interaction with the electrons (passing them part of its energy). In contrary, the part of the wave perpendicular to the wires, loses only minimum of energy, because the movement of electrons across the wire width is quite limited.

It means, from the logical point of view, the picture is perfectly correct. Showing it in the opposite way would be less correct, IMHO. However, I very much agree that explaining the light or EM wave with a mechanical model does not really describe the reality, hence you are right that the models are neither right nor wrong. Unfortunately though, in the visualization and imagination we are limited to such mechanical models and most of us simply need them to help us understanding the principles.

[wet]

Polarized - June 5, 2008 | North Coast Journal

See article and other pics

[efattah]

For those of you who believe in the wave/particle duality of light, you should read the book 'Null Physics'.

It shows in a beautiful fashion that all strange weirdness physicists have come up with is totally unnecessary, and the true explanations are much simpler and prettier.

[sanso]

Originally Posted by efattah

For those of you who believe in ... strange weirdness ... the true explanations ...

Eric, You're not trying to start a religious discussion here, are You? Especially mixed with science, this is bound to explode.

Anyone considering a reply to this thread, please bear in mind that we are not (and cannot be) talking about absolute truth here. And that only extremely few of us (if any) have enough information to argue in this discussion.

If in doubt - be friends.

[trux]

Originally Posted by sanso

Eric, You're not trying to start a religious discussion here, are You? Especially mixed with science, this is bound to explode.

Sanso, did you read the book "Null Physics" Eric recommended? I have the feeling you misunderstood Eric's words. Null Physics by Terence Witt in no way tries replacing science with religion. In fact it is the exact opposite - in many aspects we can tell that modern science is still greatly under the control of religion (+ politics and corporations) and the book tries to pull down some of the established dogmas.

The most important value of science is skepticism - permanent re-verifying of all facts and theories. Real scientists never rely on once already established theories, and always try finding new ones better matching the reality. Unfortunately religion always played an important role in suppressing science or trying to manipulate in the way matching its interests. And although it looks paradoxical, it is still the case today. The main stream Big Bang theory is taught in schools as undeniable fact, as a dogma. It very well fits the religion's interests, and that's the reason that scientist who question it, or offer alternative theories, are not far from being handled in the same way as Galileo and other heretics - they are silenced, ridiculed, refused publications, denied observatory time, denied subventions, fired, etc. With this I do not want to tell that the opponents are necessarily right, or the mainstream theories wrong. I am telling that without skepticism, without doubting established ways, and without testing new ones, there cannot be any progress.

Unfortunately I did not read the book Null Physics yet, but will definitely try getting it. I've just read some reviews. For example this one is quite appealing: Null Physics Declared a ''Significant Contribution'' to Modern Physics - Forbes.com

I'll quote only the final sentence: "Be prepared: Null Physics is advancing modern physics."

Although I did not read the book, I've read some other material being skeptical about some mainstream theories in physics and astronomy. If you are interested, these ones are not bad for those who want to make up their own opinion:

The Top 30 Problems with the Big Bang Theory by Tom Van Flandern
Halton Arp's discoveries about redshift
Exploding the big bang

[sanso]

Trux, no worries, I'm not actually talking about religion here, but used it as a different way of describing the concept of heated discussions.