May 16 – International Day of Light

Posted on May 16, 2018

Did you know that, on this date in 1960, physicist / engineer Theodore Maiman first demonstrated a laser.

And did you know that the word laser is an acronym for "Light Amplification by Stimulated Emission of Radiation"? Hooray for acronyms, which are especially cool when we're able to jam seven words into one - and save about 50 characters!

You probably know that light is like a wave (but also like a packet or particle!), and so it has crests ("upward spikes") and troughs ("downward spikes"). Most things that emit light produce a jumble of different wavelengths...

...but when light all of the same frequency and waveform is emitted from a laser, the wave forms can be (kinda sorta) "stacked" together... And that means that laser light can be focused very tightly. 

And that means that a laser beam can remain narrow while traveling a long distance (like to the Moon and back), and a laser beam can be used to cut things, and many laser beams, together, can make colorful light shows.

Lasers are used for everything from surgery to super delicate paper cutting, from bar code readers to laser printers, from DNA sequencing instruments to fiber optics communication. So hooray for Maiman, and hooray for lasers!

Today's holiday, International Day of Light, is on May 16 because of that laser anniversary, but this UNESCO holiday isn't just about the science of light - it's also about art and culture and entertainment, all of which require light but also which provide metaphoric light of their own!

There is a light photography contest as well as a variety of local events. Here are some wonderful photos of light:


No comments:

Post a Comment