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a blue desk lamp

Any desk lamp will do for this du Chatelet light project

What is the du Chatelet light project?

Emilie du Chatelet was a scientist who lived in France in the 1700s, in the time of Louis XV. She proposed this experiment as a way of showing that longer wavelengths of light heat things up more than short wavelengths do. But du Chatelet never actually did her experiment. She died in childbirth when she was only 42.

Who is Emilie du Chatelet?
Women in European history
Enlightenment Science
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Can I do Emilie du Chatelet’s experiment?

Sure! You can get colored lights and thermometers and do the experiment that du Chatelet never carried out. See for yourself whether red light will heat things up more than blue light!

What will I need?

Get a regular weather thermometer, and set it up under a strong desk lamp so the light shines on it. Also get a red bulb and a blue bulb (they should have these in the light bulb section of a big grocery store.)

More about thermometers
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And about light
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What should I do?

First put the red bulb in the lamp. Turn on the lamp and come back in 15 minutes. Now see what the thermometer reads.

What do you predict will happen when you put the blue bulb in the lamp and try again? Why? What will happen if you put a regular light bulb in? Why?

Try the blue bulb and the regular bulb and check out what happens.

Did this Emilie du Chatelet light project work for you? Why or why not? Let us know in the comments!

More about Emilie du Chatelet

Bibliography and further reading about Emilie du Chatelet:


European Women
Louis XV France
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