[SI-LIST] Honey, your conductors are ready!

  • From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>
  • To: "si-list (si-list@xxxxxxxxxxxxx)" <si-list@xxxxxxxxxxxxx>
  • Date: Thu, 13 Nov 2014 21:21:24 +0000

I thought you all might enjoy hearing the results from an experiment I recently 
concocted (but haven't yet completed).  Here's how it was crafted:
Cut 2 identical squares of aluminum foil.  Shape one of those into a ball, 
really tight and compressed (sphere = minimum surface area).  Leave the other 
one flat (maximum surface area).  Put them both in the microwave and heat them 
for 15 seconds (not sure of exact time).  See if there's a significant 
difference in the temperature between them.  The flat sheet should be much 
hotter - more surface area for the microwaves to impinge upon.
Here's what I've learned from this exercise so far:

1)      Don't do this unless you're prepared to buy a new microwave, or can 
live with lots of singe marks.

2)      If you blow the microwave circuit breaker, reset it quickly if you have 
a freezer on the same circuit.

3)      Don't have your spouse try this while you're in business in China - 
wait until you can do it properly.

4)      The foil has to be small enough not to contact the walls.

As you can guess, I asked my spouse to try it.  I'm in China but was anxious to 
hear the results.  I should have waited! :-)   Here's the text from her 
synopsis:

"Well.  Our microwave looks like he[ck] - burned the door seal, and put black 
streaks on the back wall.  My flat piece of foil was not a square - it was a 
rectangle, so the edges grazed the sides of the box insides as the tray 
rotated.  There was lots of arcing, sparking, and color.  But as far as Kath 
and I could tell, neither piece got warm!!!!   Go figure!
I could try again.  [note from Jeff: how did I find this woman?!?!]
I began with a rectangular piece approximately 4 inches by 6 inches.    Should 
have tried a square.
Had difficulty making a ball out of the one piece, after a certain point of 
compressing it.  It was a little more of a prism than circular.  But close.
We weren't clear if you wanted both pieces in the microwave at the same time, 
or if the test should be run separately for 15 seconds.  We (Kath and I) 
decided to put them both in, beside each other, but not touching.  All the 
arcing activity caused the ball to roll under the rectangle, though.  At least 
so it seemed.  The pieces were lightly stuck together when we were done."

Anyway, I still think it's a cool demonstration of the fundamental principle 
that a layman can try (if they're brave or dumb).  There's a nice limit that, 
if the sphere is small enough to equal the skin depth, the two pieces will heat 
evenly (I think).  I'm anxious to try it when I get home.

If you choose to try this in the next week at the risk of your microwave and 
food in your freezer, please let me know what you find.

Cheers,
Jeff Loyer

------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field


List forum  is accessible at:
               http://tech.groups.yahoo.com/group/si-list

List archives are viewable at:     
                //www.freelists.org/archives/si-list
 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu

Other related posts:

  1. Home
  2. si-list
  3. Archive
  4. 11-2014