Wednesday, July 18, 2018

Be careful with your parabolic mirror


Let's say you you were into making solar ovens. Let's say that you decided a few years ago to make the best solar oven ever. Further, let's stipulate that you saw a nearly meter-diameter Direct TV antenna on the side of the road. An idea happened. You rushed to the local plastics store and bought highly reflective Mylar and glued it to the antenna.

Your solar oven was pretty amazing. While the hot spot wasn't super small, it was hot. Really hot. It can pasteurize a liter of water in 15 minutes.

And now you work at the Exploratorium and you think that you might bring it to work for grins. If you forget it in the back of the your Outback face up on a sunny day near the solstice, well, it can melt the molding in a fairly impressive way. I think I was lucky that my car didn't catch on fire.



You might be wondering how I could make such a mistake? I had a lot to carry into the Exploratorium, and the mirror wouldn't fit on the cart. I planned on coming back in a few minutes, but I got busy doing something else, and it slipped my mind. Coming back in the afternoon, I sat in the driver seat and looked into the rear view mirror.

Uh oh.



If you want to make your own parabolic mirror, you can find some excellent instructions here.

Marc "Zeke" Kossover

11 comments:

Bree Barnett Dreyfuss said...

I think an energy calculation should be made for that liter of water;)

Anonymous said...

Congrats! You made to the front page of imgur: https://imgur.com/gallery/3B2b3UW

Anonymous said...

You got lucky and have a good story to tell! It's so easy to overlook the risks of relatively new things in life or a component in an unusual context.

Colin said...

Frank Gehry, call your office. (Or stop by the Disney Concert Hall.) See: https://en.wikipedia.org/wiki/Walt_Disney_Concert_Hall

Puck Bacchus said...

Don't feel bad. Archimedes made the same mistake.

Unknown said...

Best article I have read today. Thank you.

Mr. Satyre said...

Back in the 90s, I had the exact same thing happen to me with a LaserDisc I had left on the back dash.

tim ferrell said...

Don't lie, it was aliens!!

Anonymous said...

You said it was a DirecTV satellite dish?

Those aren't parabolic, they're elliptic.

The transmitter is a single point, not a parallel source.

The Nörsk-in-law said...

Never happened. Archimedes drove a convertible Miata.

Unknown said...

All you'd need is a tracking system and a, a large spinning mirror and you can vaporize a human target from space.