ultraviolet

/Tag: ultraviolet

Radioactivity and sunburns – Physics

By |2018-04-24T12:26:12-07:00August 17th, 2017|Physics|

Radiation from the sun caused this sunburned back The most common kind of radiation is sunlight, and the most common cause of injury from radiation is a sunburn. Just like radioactivity from a nuclear explosion, radiation from the sun can damage the DNA of your cells. Later the same day, or the next day, your skin may be red and sore. [...]

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, [...]

What is light made of? Why is the sky blue?

By |2018-05-31T11:49:14-07:00August 16th, 2017|Physics|

Rainbow over Amazon river Light is made of billions of tiny particles called photons. These photons travel from one place to another in waves. Visible light is the subset of photons that move at a wavelength that we can see. Among the different photons that are in visible light, the ones that have the [...]