Speed of Light

My post is in error. Where I wrote neutrons, substitute charged particles. Neutrons have no net electric charge and do not disrupt the EM field of nearby atoms/molecules past which the particle travels. Protons, electrons, alpha particles (helium nuclei) and other charged particles can induce a dielectric medium (such as water) to emit Cerenkov radiation, provided the particles are travelling faster than the speed of light in the medium. Where neutrons disrupt an atom, the atom may emit charged particles which produce Cerenkov radiation as a secondary effect. My apologies for the earlier misinformation.

-e

...at a speed faster than the speed of light in water...After they dump their energy in this way, they slow down and behave themselves...

Are you implying that Localised Phenomena may break conservation or symmetry laws untaxed?

Hi europium. Am I right in saying that your picture has been taken inside a nuclear reactor? If so, then the light is produced by free neutrons hitting the molecules of the heavy water that surrounds the core?

Also note that the refractive index of a medium is a function of wavelength. This effect, called dispersion, explains why prisms split white light into different colors and what gives diamonds and CZs their "fire."

Good morning europium. Yes you are right, but there is another phenomonen, it is called "Birefringence". This is the measure of a solids ability to convert a single ray of light into two rays with unequal velocities in two directions. The numerical value for a gemstones birefringence is obtained by subtracting the lowest refractive index from the highest for that gemstone. These light rays vibrate in two planes at right angles to one another, and each ray is plane polarized, thus these gems are called anisotropic. The gemstones that are cut from crystals of the cubic system of symmetry, diamonds, garnets, spinels etc do not exhibit this phenomonen, they are called isotropic, so the velocity of the light travels through them at the same speed in every direction. To complicate matters even more, anisotropic gemstones do not show the same degree of dicroism when veiwed from different angles, and if viewed through the C axis they are isotropic. This dicroism which is related to birefringence gives rise to the phenononen of different colours to a gemstone when viewed in different directions, but it only relates to coloured gemstones. There are also a few gemstones that show tricroism. Yes I am a gemmologist and mineralogist, and I have studied light. Spencer.

Hi Spencer, Yes, birefringence acts to polarize light (split into so-called 'ordinary' and 'extraordinary' rays). I've seen materials that are dichroic as well. One of them was Nd:glass, a material used in high-power lasers as the amplifying medium. Some people make jewelery from bad or damaged Nd:glass rods, and I once bought a bolo tie made with this stuff. It was quite beautiful. As a junior in high school I used a crystal of potassium deuterium phosphate (KDP) to modulate the polarization angle of laser light by means of a modulated electric field applied across the crystal's faces. Following the KDP crystal was an 'analyzer' prism - a fixed polarizer - which blocked or transmitted the light depending on polarization angle. The overall effect was to amplitude-modulate the laser light, which I did to transmit a television signal over the beam. My research paper won me my very first airplane ride! -e

Hi europium. We also use polarizing instruments to determine if a gemstone is of the cubic system or not. We also use them to determine if a gemstone or mineral is Uniaxial or Biaxial. To do this a gemstone is placed between crossed polaroid plates, the stone in question is then rotated 360 degrees, if we get a patern of light and dark as the stone is rotated then it is definately not of the cubic system of symmetry. All the gemstones and minerals that are of the tetragonal, hexagonal and trigonal systems of symmetry are Uniaxial, while the stones of the orthorhombic, monoclinic and triclinic are of the Biaxial. Uniaxial means that the gemstones exhibit One extrordinary ray, Biaxial stones exhibit two extrordinary rays. Spencer.

Well, I think Larry, the Cable Guy, puts things in true perspective: "O. K., so what's the speed of dark?"

Dark Energy travels at the speed of dark, d, where d = -c. That is to say, dark always travels backward.

And, as everyone knows, E_D = M_Dd^{2 ???}. This is not a question. Those three question marks are part of the equation.

-e

-e wrote: "And, as everyone knows, E_D = M_Dd^{2 ???}. This is not a question. Those three question marks are part of the equation."

Cool^!!!

That is one powerful exclamation, Jorrie!

-e

If the right force was applied to a light wave, it could be bent back upon itself and travel the same path back to origin.

Arrrrrrrrrr! Me think-st that's one of those new fangled wizard devices! I think they calls it a "mirror!!!"

http://www.space.com/scienceastronomy/blackhole_history_030128-1.html

The speed (c) of a ray of light is equal to it's wave length (wl) times it's frequency (f). c = wl * f Thus the wave length and frequency of a ray of light are inversly proportional to each other. The only change that we see in a ray of light as we move towards or away from it's source (such as a star or gallaxy) is the wavelength and frequency. Moving away from a source of light reduces the appearent energy of the light by reducing it's frequencey and increasing it's wave length (red shift). Moving towards a source of light increases the appearent energy of the light by increasing it's frequency and reducing it's wave length (blue shift). No matter what, the speed of the light is always the same.

Hi Harbinger. The speed of light stays the same no matter what! No it doesn't, see my earlier blog. Spencer.

Dark energy's long history http://www.astronomy.com/asy/default.aspx?c=a&id=4675

The fact that this thread is still going is proof enough that we all exist in some form or other...

I fully expect this year's Nobel prize in the field of hyperbole!

For this year's leading candidate, please see: http://cr4.globalspec.com/comment/45299/Re-How-to-Get-Rid-of-the-Incandescent-Light-Bulb