The More You Know: Microwaves and magnetrons

In an otherwise hearty debate on the advisability of using other settings besides 'high' on a microwave, Quarter to Three forumer Roger Wong explains the magic of the magnetron:

The water in most food absorbs microwaves rapidly so that in a container, about only the first half inch of food gets heated. The rest of the food is only warmed by convection of this heat to the remainder.

To warm food up evenly, you can either sculpt the food up the edges of the container, or you can use the power setting.

The power setting toggles the magnetron in cycles. During the active cycle, the outer layer of food is heated up. During the inactive cycle, the outer layer of food dissipates its energy to the remainder of the food.

This prevents the outer layer of food from absorbing too much energy too quickly and burning.

Huh!

[#1 posted by Enochrewt , August 4, 2008 1:47 PM]

I set the power setting on my Microwave to 50% almost exclusively. I wish my microwave defaulted to it. Yeah, the food might take a minute longer, but it's a much better cook than at full power.

The silliest problem with my microwave pops up though, If I stick it at 50% power, for 4 minutes, usually the last 20-30 seconds of cook time are part of the "cooldown period" and the magnetron is off. It's kind of pointless, but those last 30 seconds the food can cooldown in my hands or mouth. Can I get a smart microwave?

And oh yeah, I want my personal jetpack and robot maid now too please.

[#2 posted by Alan , August 5, 2008 8:53 AM]

Well, that certainly explains a lot. I always wondered what point there was in that.