Jeopardy "Magnet" question - hard or easy?

[gmax137]

I was watching Jeopardy last night. In the Category "Magnet" was the following:

"An 1845 letter from the 21-year-old future Lord Kelvin inspired this British scientist to show how magnetism & light are related"

My guess:

Spoiler

Maxwell

I was pretty sure this was wrong, based on the 1845 time frame, but I couldn't come up with another answer before the buzzer.

The contestant obviously didn't know either, she finally said,

Spoiler

"Who is Cavendish"

The right answer

Spoiler

"Faraday"

Would you get that right? The Jeopardy "science" questions are almost always easy definitions (like, "It is denoted by 'c' in the famous Einstein equation E=mc2").

 

[fresh_42]

Yes. (I probably watch too many documentaries.)

 

[berkeman]

I got it wrong as well, but I don't remember what my reply was. Pretty embarassing, but I'm not very good with those old dates / timeframes.

 

[Vanadium 50]

I was pretty sure this was wrong, based on the 1845 time frame

Good guess, since Maxwell would have been 14. The easy way to sequence Maxwell and Faraday is to recognize that Maxwell's equations subsume Faraday's Law. Cavendish is in the wrong direction.

 

[gmax137]

What tripped me up was magnetism and light. When I think of Faraday, it's induced currents, dynamos, etc., not light.

But,
https://en.wikipedia.org/wiki/Faraday_effect :

In physics, the Faraday effect or Faraday rotation is a magneto-optical phenomenon—that is, an interaction between light and a magnetic field in a medium. (The effect is also sometimes referred to as the magneto-optic Faraday effect or MOFE.[1]) The Faraday effect causes a rotation of the plane of polarization which is linearly proportional to the component of the magnetic field in the direction of propagation.​

I must have missed that in my EM class. But that was 40+ years ago, so who knows.