Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
|Re: Radiation And Light
Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Wayne/">Wayne on January 14, 2000 16:17:34 UTC
CL: What do you consider to be light???
Wayne: Light is the "atmosphere" or "medium" that radiation travels through. Light and space are the same. It is the "ocean" the universe swims in, or the "air" it flys through. Radiation and light are seperate entities. Just as sound waves and water or atmosphere are seperate entities. One travels through the other.
CL: Electromagnetic radiation travels at the speed of light to us. Wayne: No, it travels at the speed of electromagnetic radiation, through light, just like sound waves through water. Again, they are not the same thing.
CL: It then hits our body. The infrared spectrum is then absorbed by our skin which we sence as heat. The ultraviolet spectrum is also absorbed by our skin.....more heat! There is another spectrum that is absorbed by particles in our skin causing us to sence heat. But because this spectrum also vibrates little cells in our eyes that transmit a signal to our brain..... which then interprets the signal and creates an image, we call this spectrum visible light.
Wayne: This last statement is my point. We "CALL" it visible light. It's not, it's visible radiation.
CL: It's not what makes light, it's how WE SENCE it. It's all made of the same "stuff"; to sensitive and we don't sence it, not sensitive enough and we still don't. It has to be in just the right slot to be "seen and not just felt.
Wayne: Just like sound waves. I can stand near an amp and hear, as well as feel some low frequencies thumping my chest and ears. But I don't see the medium those waves travel through, and I don't hear all the frequencies.
CL: Your argument to me would insinuate that the sound frequencies we don't hear are something other than the sound frequencies we do hear; almost as if we "hear through air instantaneously at the spot where the noise is".
Wayne: It shouldn't insinuate that. Radiation (waves or particles) are probably very much like sound. It is the medium they travel through that effects the speed. Bass note from an amp (travels through unseen air) hits my shirt and gets slowed down and partly absorbed. Radiation from the sun (travels through unseen light) hits my shirt and gets slowed down and partly absorbed.
CL: But this in no way explains the dopler shift or the speed of sound. Ask a someone that uses sonar if we hear through sound waves instaneously to the source. Light is the same principle.
Wayne: If someone points a distant cannon at you and fires. You see the flash then hear the audible sound wave. The Doppler shift tells you (assuming you know the blast frequency) if the cannon is in motion when it fires. Radiation will act the same way as it travels through light. You will see the flash of the blast of an exploding star, and then the radiation from the blast will reach you later.
CL: Also, we once used light to measure the distance to the moon. A laser was reflected off a mirror on the moon and timed. When the light returned we plugged in the obvios equation and there was the distance. If we saw through light, then it would never have returnd. It would have made a one way trip to the moon, lit it up, and then we would've seen through it instantly;........giving half the distance.
Wayne: We used "radiation" from a laser through light just like a sonar ping through water. The radiation bounces back through the light.
Unless otherwise specified, web site content Copyright 1994-2020 John Huggins All Rights Reserved
Forum posts are Copyright their authors as specified in the heading above the post.
"dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
are trademarks of John Huggins