Optical Definition and 701 Threads

We are all familiar with the illusion of the wheels on a car on television appearing to spin backwards when the car is traveling forward, this being caused by a mismatch of the picture frequency and the wheel's rotational speed. However I have also observed this phenomenon in the real world...

Can anyone tell me the reason why an enatiomer rotates the plane of polarised light? Or at least tell me where i can read more on the reason why some compounds exibit optical activity. Thanx Saurya

The group velocity is always negative except k=0 and k=Pi/a in the optical mode, is there a reason from the general picture of crystal vibration? Well, it seems to me that optical mode describes the situation that different atoms in a unit cell have opposite motions. Also, in the optical...

How optical mouse to work? What's principle of the physics? thanks b4

How does an optical computer mouse know which way it is moving?

Hi do u know what phase velocity is>? I have found it a boot for optical fibers vp=1/(srqt(em) m denotes greek m letter

Hi i have some questions concerning optical fibers.. I want to know how the single mode fiber works.. I know that the light in sinle mode fiber travels across the middle of the fiber.. I can't understand why if we bend a little the fiber why the light don't hit the walls of the fiber? Thx a lot

Some really good stuff here. http://people.deas.harvard.edu/~jones/ap216/lectures/lectures.html R. VICTOR JONES Robert L. Wallace Research Professor of Applied Physics Division of Engineering and Applied Sciences Pierce Hall Havard University 29 Oxford St. Cambridge, MA 02138

Hi, I'm trying to set up a lens system as follows: - Laser source 612nm - This passes through an apature to act as a spatial filter... - then through non-reflective glass onto a crystal of diameter upto 150um - the lens must then take the diffraction pattern from this crystal upto...

A few days ago a buddy of mine showed me a two year old article, telling that Israel have developed an optical CPU. I did check i further and it is true, but I can not understand how such a device can work.. Is there anyone who could explain it to me?

You can just google it so I won't get in trouble for linking to it. Anyone ever looked at it? It looks like just optical illusion silliness to me but is there any possibility of some other sort of thing going on? Was just wodering if anyone ever did anything meaningful there in the way of...

http://viscog.beckman.uiuc.edu/grafs/demos/15.html" View this video. (Requires Java.) Feel free to view it as many times as necessary. Then answer the poll question. I will wait a day or two, then post the result.

Hi all. It has been a while since I last posted. I was reading a couple of days ago about optical isomers. I found that L-type isomers cost more than D-type isomers, to manufacture and sell. I was wondering if anyone knew why? Because of the new rules on PF, I am going to state what I...

A few optical illusions and their explanation I thought this was a cool site, usually when I find a site that has optical illusions it simply states what to do and what you will see. Mr. Bach proceeds to give, brief, but yet good explanations of why the effect happens, and sources too, very...

Hello everbody, long time no see! I hope this is the right forum for this, I'm not ready to post it in the topology forum:cry: Okay, so I saw this neat optical illusion. It really started to bug me as I was playing around with it in paint trying to figure it out...

Ze Optical Boom By Albert Einstein ze Sird In nineteen forty-somesing, ze venerable Chuck Yeager became ze first human on ze planet to break ze sound barrier. He also did zis, I might add, wizout becoming his own daddy. Of course, humans travel faster zan ze speed of sound all ze time...

Does anybody know what can be the reason for such an aberration of initially Gaussian shaped laser beam (see attached picture)? Optical elements in the light path: linearly polarized diode 470nm laser, single mode polarization conserving fiber, collimator, mirror, lens, round 50 micrometer...

In reading about Bell tests I found this link:http://www.abc.net.au/science/features/quantum/, which has discussion of numerous loopholes in both theory and experimental design of Bell tests, which when combined, appear to suggest that "local realist" explanations of all Bell test violations...

I'm doing a presentation in this topic and I find it very hard to look for information on the web. Please, point me to any website or resources that have information about this topic? Thank You~! :confused:

Hello everyone, I'm not sure if this is in the correct topic, so please move to a correct one if need be. Are there any mathematical relationships between the wavelength or frequency of an electromagnetic ray and the optical properties of a material? By optical properties, I mean the...

Optical "coherence" A question on the nature of coherence that came up on Wikipedia... If we pass the light from a laser through a stack of frosted plates, is the result still "coherent light?" For most optical applications requiring coherent light, this type of heavily diffused laser light...

hi to all, question is the following: the equation for optical diffraction due to diffraction grating is written as: G*m*lamda=sin(a)+sin(b) if the incident light beam is not perpendicular to the grooves, the equation becomes G*m*lamda=(sin(a)+sin(b)) * cos(e) where e is the...

Anyone know an easy way to print a rotary encoder with x number of pulses/revolution? Is there like a program that can easily do this? I probably need a few hundred so it's going to be hard to draw them by hand. Thanks

I think this is the forum this question belongs in. I was looking at this shifty red pen I have and I though about an optics and light question. How do optical illusions work? Is there some kind of physics theorum or idea which would explain how this works? I hope this makes sense.

It seems that a major concern in the fabrication of optical fibers is hydroxyl diffusion into the fibers. I understand that a high hydroxyl concentration can lead to much higher attenuation. I don't know why though. Can someone please explain to me why the hydroxyl concentration affects...

These folks are modeling the optical effects "gravitational" lensing in terms of vacuum polarization. I think they are on the right track conceptually, but that the mechanism that causes polarization is far more basic - a differential in the gravitational infall rates of matter vs. matter...

Hello, How can we convert parallel-to-serial address and send it as an optical signal? Have a look at the link below if you folks don't know what I mean - the last (3-4 lines) paragraph of the pdf file: http://www.hep.yorku.ca/menary/courses/electronics/3150/lab_manual/opt.pdf...

Three Interconnected Questions: 1. When an atom is excited by a visible photon (KE=1 eV), does the probability (radial) density increase for the valence electrons or not? 2. If the probability density has increased outward, then what normally causes the excited state to begin the process...

This optical illusion is driving me nuts. I know the answer. I know the two squares are the same color, but I cannot convince my brain to believe it. http://wavelets.mit.edu/~bharath/image-store/checkershadow-AB.jpg there are a few neat optical illusions here http://web.mit.edu/persci/gaz/#

hi, if levo tartric acid was reduced to its ketone derivative would it produce exclusivly the levo form or would a racemic mix be formed or even the dextro form be formed? (any examples you give me don't have to be for tartric acid i was just using it as an example as I've been reading the...

:confused: Hello everyone: I am a newbie in Quantum Chemistry and I want to do some calculation on some physical properties such as the title shows. However, as we know, lots of package can't give you exactly what you want,you have to tackle with some succeeding process to get a beatiful...

Help Wanted: Lone maths freak seeks aid from physicists for research into optical trapping/optical tweezers Ok just for the benefit of those who may not be aware, Optical tweezers or optical traps are a relatively recent experimental technique in which focused lasers are used to trap...

Optical isomers... Optical isomers are so called because they apparently "have differing effects on polarised light" - what exactly happens and why? Thanks in advance. :smile:

People seem very quick to proclaim Quantum Computing as the solution to faster computers, however the development of Optical Computers rarely rate a mention. The motivation behind this thread is to give some awareness as to what optical computing is and what it is capable of and hopefully invite...

The smallest outside radius, R, permitted for a bend in an optical fiber if no light is to escape is called the minimum bend radius. I know that it is proportional to the fiber's diameter, but I don't understand why. Any thoughts?

This is the question: The optical path length of a light beam is nd where n is the refractive index and d is the physical distance. A light beam passes through 2.0 in thick glass (n=1.525) and then through 12 in. of water (n=1.33) and finally though 0.6 in of polystyrene (n=1.590). What is the...

"The imaginary part of the forward scattering amplitude is proprtional to the total cross section" OK, so what is the link with Optics !? :confused: :rolleyes: I am not sure I got the right forum, I just didn't know which would be better for that (stupid) question

why we use composed lentiform in optical science?

Hello! Um...can anyone help me with this question? A woman can see clearly with her right eye only when objects are between 40.0 cm and 177 cm away. Prescription bifocals should have what power (in Diopter) so that she can see distant objects clearly (upper part)? Assume that the glasses will...

I'm looking for the electrical and optical properties of Cadmium Sulphide. Any links of info would be much appreciated

Address:http://www.ebaumsworld.com/ I found this one to be more interesting than most because of counter rotation.

I designed an optical A/D (on paper only) several years ago. I have no means to make one since small scale integration is required. Any ideas how to get someone interested? If it works correctly, there would be zero conversion time and only settling time for the detectors outputs.

I thought this was interesting. Anyone here into biomimetics that has additional examples they can share? (see link for full article) Bell Labs scientists find novel optical fibers in deep-sea sponges Scientists from Lucent Technologies' Bell Labs have found that a deep-sea sponge contains...

Hi, I'm hoping I can get some help. (I'm a first time poster, so if there's something that isn't quite clear, please let me know). A converging lens (n=1.355) in air has diameter 4.0cm, thickness 0.50cm and zero thickness at its edges. A point object at 'So' = 18cm has an image at 'Si'=...

Black Dots http://www.cse.unsw.edu.au/~geoffo/humour/opticals/black-dots.jpg Spinning Wheels http://www.cse.unsw.edu.au/~geoffo/humour/opticals/spinning-wheels.jpg

Does someone can explain that? The transition frequency v of atoms exposed to the lattice electric field of E is described as, hv = hv^(0)-(1/4) alpha(e,w)E^2-(1/64) gama(e,w)E^4 where v^(0) is the transition frequency between the unperturbed atomic states, alpha(e,w) and gama(e,w) are...

Does anyone know any good websites/resources etc to do with optical computing? I have found some good websites and papers, but the more the better. Some technical information is preferred but anything to do with optical computing I would find useful. Some topics in particular I am looking...

Optical Illusions Turn on [edit: off] your sound: http://www.liquidgeneration.com/sabotage/optical_sabotage.asp eh..I didn't have time to finish this earlier. I just now saw the end. :wink:

Whats up? I have a question, please? What is the closest distance at which an eye can see objects clearly? My answer is the near point, is that right? Thanks! Dx :wink:

My friend just bought a mini disc player, and apparently it uses an optical cable to connect to a computer. I think I know what an optical cable is, but I've never heard of an optical port, and I've never seen one on a comp before. Are they a fairly recent development, or am I just blind?