let me tell you about my roommate
she is a graduate of texas a&m university and is very proud of it. she graduated about 4 or 5 years ago, but this seems to still be how she identifies with the world. the first question she asks people is where they went to college, and i'm sure it's so she can in turn tell them she went to a&m. get over it, let's talk about your life now.
anyway, last night she asked me to press clear on the microwave from now on if i took the food out before it was finished (before it beeped). i was puzzled, so i asked her why, and here is what she answered:
the microwave still radiates until it beeps. if you pull food out before that time, it still thinks that it is cooking something so it keeps radiating so that the food won't get cold.
now, i don't have a college degree, but common sense tells me that a microwave is not going to cook anything unless i press "start". microwaves are not intelligent computers, they can't do what i don't tell them to do.
please, am i crazy, or is she?
posted by trish @ 1:25 PM
2 comments
2 Comments:
Personally I think that your roommate is full of shit but you can always test her theory. I can't imagine that the makers of microwaves would have them radiate when not in use. I will probably test this theory myself now because I am kind of curious. I will let you know how it turns out.
Microwaves don't "cook" anything, in the sense that it creates heat like conventional ovens.
A microwave oven works by passing microwave radiation, usually at a frequency of 2450 MHz (a wavelength of 12.24 cm), through the food. Water, fat, and sugar molecules in the food absorb energy from the microwave beam in a process called dielectric heating. Most molecules are electric dipoles, meaning that they have a positive charge at one end and a negative charge at the other, and is therefore twisted to and fro as it tries to align itself with the alternating electric field induced by the microwave beam. This molecular movement creates heat.
The cooking chamber itself is a Faraday cage enclosure to prevent the microwaves escaping into the surroundings. The oven door is usually a glass panel, but has a layer of conductive mesh to maintain the shielding. Since the mesh width is much less than the wavelength of 12 cm, the microwave radiation can not pass through the door, while visible light (with a much shorter wavelength) can.
So yeah. If there's nothing in the microwave, there is no heat.
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