X-ray Definition and 309 Threads

Faster than c! hi I read that the refractive index(n) for X-rays in meterials are less than 1(very little less than 1). I got confused ..I am using X-ray reflection at the moment. But I am not convinced by the fact that n<1 means faster than c(velocity of light in vacuum or in air)! hope...

Here's an interesting problem: Find the atomic spacing in a crystal of rock salt (NaCl). The density of rock salt is 2.16 * 10^3 kg/m^3 and the average masses of the Na and Cl atoms are respectively 3.82 * 10^-26 kg and 5.89 * 10^-26 kg. Now I know that density (Rho) = mass/volume and 2d sin...

can anyone explain howz x-ray been produced. thank you

http://www.astronomy.com/Content/Dynamic/Articles/000/000/001/604djcxv.asp XMM-Newton studies the X-ray universe from Earth orbit. ESA A mystery that has been haunting the fields of physics and cosmology has just grown deeper. Dark energy, that stealthy ghost that lurks in the...

Does anyone remember when Pravda only told the government's lies? I am posting this as a reminder that IMHO, Pravda is not a valid news source. http://english.pravda.ru/science/19/94/377/11797_phenomenon.html

I'm having a little bit of a problem with this one. Here's the question: X-ray pulses from Cygnus X-1, a celestial x-ray source, have been recorded during high-altitude rocket flights. The signals can be interpreted as originating when a blob of ionized matter orbits a black hole with a...

Heres the problem: An x-ray tube used for cancer therapy operates at 4.0 MV, with a beam current of 25 mA striking the metal target.Nearly all of this power is transferred to a stream of water flowing through the holes drilled in the target. What rate of flow, in Kg/sec, is needed if the...

" To the eye, she is dressed in a skirt and blazer in dark, businesslike colors. On the monitor she is naked..." http://news.yahoo.com/news?tmpl=story2&u=/030625/168/4i6lv.html&e=1&ncid=1756

does anybody know of any current work that is being done to improve x-ray crystalography techniques?