vikneshraj Posted August 20, 2007 Report Posted August 20, 2007 Hello,I am viknesh raj,I would like yo ask aquestion...... Is ther an ray that cannot permit any coloured light rays to pass through it?please help me to kow about it...... thank you.............. Quote
Tormod Posted August 20, 2007 Report Posted August 20, 2007 Welcome! And sorry I don't quite understand the question. Maybe someone else can help out! :eek2: Quote
Pyrotex Posted August 20, 2007 Report Posted August 20, 2007 Hello,I am viknesh raj,I would like yo ask aquestion...... Is ther an ray that cannot permit any coloured light rays to pass through it?please help me to kow about it...... thank you.............. Hello vikneshraj. Welcome to Hypography. I will try to answer. I will give several answers. If you are asking for a "ray" that cannot permit other "rays" to pass through, then the answer is NO. All rays of light can always pass through each other. Red light cannot block blue light. If you are asking for a "ray" that cannot have any color, then the answer is YES and NO. "Color" is a word we use for the light we see with our eyes. If we see the rays, then they must be a color or a mixture of colors. If we do NOT see the rays, then perhaps they are Infrared or Ultra-violet, which we cannot see. They have no color because we cannot see them. However, another word for "color" is wavelength. Every ray has a wavelength, some for long (red and Infrared) and some very short (violet and ultraviolet). So, I would say EVERY ray has a color in this sense. If you are asking for a material that cannot pass rays of any color, then the answer is YES. Most materials, like brick and iron, block all light from going through them. I hope this helps. Pyrotex Quote
eric l Posted August 21, 2007 Report Posted August 21, 2007 Would it be possible to reflect a ray of monochromatic light in such a way that the reflected ray is 180° out of phase compared to the incoming ray, so that they effectively neutralize each other ? Theoretically ? (I don't think it feasable in practice) Quote
Pyrotex Posted August 21, 2007 Report Posted August 21, 2007 Would it be possible to reflect a ray of monochromatic light in such a way that the reflected ray is 180° out of phase compared to the incoming ray, so that they effectively neutralize each other ? Theoretically ? (I don't think it feasable in practice) Yes. Using any astronomy grade mirror, you can put a transparent coating on it (say, Magnesium Flouride), and make the coating exactly 1/4 wavelength thick. I am assuming the incident ray is normal to the surface of the mirror. Now, evaporate/condense a thin layer of aluminum down over the quarter wave coating. You want it to reflect about 45%. 45% of the light should go through the top layer, through the coating, reflect off the mirror and come back out the top layer, where it will be 180 degrees out of phase with the light reflecting off the top layer. The other 10% will be internally absorbed. Ideally, no light at all will reflect, at that monochromatic wavelength. Actually, these kind of tricks are done all the time with high-end optics, especially in astronomy. GAHD and eric l 2 Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.