Speed of light fibre optic signals which travel 30–40% slower at the speed of light through glass. There are different ways to determine the value of "c". One way is to measure the actual speed at which light waves propagate, which can be done in various astronomical and earth-based setups. However, it is also possible to determine "c" from other physical laws where it appears, for example, by determining the values of the electromagnetic constants "ε" and "μ" and using their relation to "c". Historically, the most accurate results have been obtained by separately determining the frequency and wavelength of a light beam,
Synchrotron-Light for Experimental Science and Applications in the Middle East the current director and former vice-president of SESAME. Synchrotron light (also referred to as synchrotron radiation) is radiation that is emitted when charged particles moving at speeds near the speed of light are forced to change direction by a magnetic field. It is the brightest artificial source of X-rays, allowing for the detailed study of molecular structures. When synchrotrons were first developed, their primary purpose was to accelerate particles for the study of the nucleus. Today, there are almost 60 synchrotron light sources around the world dedicated to exploiting the special qualities, which allow it to be used across a