or replacing one mystery with another!
The Enduring Mystery of Light
By Michael Schirber
Special to LiveScience
posted: 26 February 2007
09:14 am ET
Is it a wave?
What ties together microwaves, X-rays and the colors of the rainbow is that they are all waves—electromagnetic waves to be exact. The substance that sloshes back and forth isn't water or air, but a combination of electric and magnetic fields
Or is it a particle?
But waves are not the whole story. Light is composed of particles called photons. This is most obvious with higher energy light, like X-rays and gamma rays, but it is true all the way down to radio waves.
Albert Einstein deciphered the mystery in 1905 by assuming that particles of light smacked into the electrons, like colliding billiard balls. Only particles from short wavelength light can give a hard enough kick.
Despite this success, the particle theory never replaced the wave theory, since only waves can describe how light interferes with itself when it passes through two slits. We therefore have to live with light being both a particle and a wave—sometimes acting as hard as a rock, sometimes as soft as a ripple.
Instead of worrying about what light is, it might be better to concentrate on what light does. Light shakes, twists and shoves the charged particles (like electrons) that reside in all materials.
These light actions are wavelength-specific. Or to say it another way, each material responds only to a particular set of wavelengths.
Technorati Cosmos: other blogs commenting on this post
3 comments:
Ultrasonic
The knowledge of ultrasonic(sounds) is from relatively young date and of certain technicals of which one came only to speak during the last 60 years. The problems with submarines during world war I were a reason that the famous French scientist Paul Langevin (1872-1946) executed extended studies and experiments. He achieved for the first time practical results when he could establish the presence of submarines under water. During these experiments some biological effects were discovered too, as some micro organisms like algae cells were hit by the ultrasonic beams and died.
Since then thousands of publications about this phenomenon were published on the basis of which applications like the algae killing devices.
Would have worked
Crystals such as cordierite, calcite or turmaline work like polarizing filters, changing in brightness and color as they detect the angle of sunlight
"Under foggy or cloudy conditions a Viking navigator could have guessed the position of the sun hidden by clouds or fog by determining the sky light polarization in two celestial points ... and could have guessed the position of the invisible sun," said Horvath, of Eotvos University in Budapest. "Although all these are pure hypotheses, researchers can test the scientific possibility of such a polarimetric navigation."
Thanks for the tip, but what do I do about it? Almost everyone that I have met on Mybloglog.com has told me that, but never explained what I should do about it.
By the way, thanks for commenting on my blog.
Johnna
Post a Comment