Pulsars

Not much pressure, to be sure – but it's a finding that's fascinatingly consistent with Stephen Hawking's prediction that black holes emit radiation and therefore not only have a temperature, but slowly shrink over time, in the absence of accretion.

The German scientist was the first person to identify electromagnetic radiation in a wavelength that we today know as an x-ray.

The most common usage of x-rays includes detecting broken or fractured bones, heart problems, breast cancer, scoliosis, and tumors. X-ra...

Substances like minerals, plants, fungi, microbes, and organic and inorganic chemicals, can absorb UV radiation, causing electrons to jump to a higher energy level. When the electrons return to a lower energy level, they emit a portion of the absorbed energy as visible light.