Today we celebrate the birthday of the Russian physicist Pyotr Nikolayevich Lebedev (8 Mar 1866 – 1 Apr 1912).

Working in the field of electromagnetism, Lebedev was responsible for a rather famous physics experiment in 1899 – measuring the pressure a beam of light exerts on a solid body. By doing this, he was the first to quantitatively confirm James Clark Maxwell’s theory of electromagnetism. Not only did he prove that the pressure exerted by light, although minute, is very real – he also proved that the pressure of light on a reflective surface is twice as great as on absorbent surfaces.

Thanks to Pyotr Lebedev we have proof that light exerts physical pressure on a solid body.(© All Rights Reserved)
Thanks to Pyotr Lebedev we have proof that light exerts physical pressure on a solid body.
(© All Rights Reserved)

Lebedev’s discoveries led him to postulate that it was the pressure exerted by sunlight on tiny particles of cosmic dust that made the tail of a comet point away from the Sun. However, it is now generally accepted that solar wind has more effect than light pressure in determining the direction of a comet’s tail.

Lebedev died quite young, yet his achievements was significant enough that the Lebedev Physical Institute in Moscow and the lunar crater Lebedev are named after him.

5 Comments

Leave a Reply to Sciencelens Cancel reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s