x-rays

/Tag: x-rays

The human body in medieval and modern science

By |2018-04-25T17:09:55-07:00September 6th, 2017|Biology, Science|

Chinese drawing of the organs (about 1200) Between the Middle Ages and modern times, doctors have learned a lot of new things about how human bodies work. The Islamic doctor Al-Tabari, in the early 800s, learned that light bounces off objects into your eyes. Al-Tabari's student Al Razi figured out that a fever is your body's way of fighting illness, not [...]

What is a photon? Physics of light

By |2018-05-31T11:49:28-07:00August 16th, 2017|Physics|

Photons - Sunshine breaking through the clouds. When did the first photons appear? A photon is a tiny little particle of light, far too small to see individually. All light is made of photons (FOE-tahns). The earliest photons probably appeared about fifteen billion years ago, during the Big Bang. What's the speed of light? Unlike electrons and quarks, [...]