Naked Science Forum

Non Life Sciences => Technology => Topic started by: Sai Emrys on 22/07/2010 13:30:02

Title: Could we invent a "cold" microwave?
Post by: Sai Emrys on 22/07/2010 13:30:02

Sai Emrys  asked the Naked Scientists:
   
What completes this analogy?

oven:freezer::microwave:_____

Basically, could one have a microwave-like appliance (i.e. one that
does not itself have significant heat/cold yet works at short
distance) which makes food colder rather than warmer?

- Sai

What do you think?

Title: Could we invent a
Post by: JP on 22/07/2010 14:56:55

I don't know about food, but you can cool gas with lasers.  You have to tune them right so that the interaction of the gas molecules with the laser causes the gas to lose some of its heat energy in the form of photons.

http://en.wikipedia.org/wiki/Laser_cooling

Title: Could we invent a
Post by: Kryptid on 30/07/2010 21:37:03

Laser cooling would be interesting, but given the way it works I don't see how it could be used on solid, chemically-complex objects like food. At least not in the immediate future. You have an awful lot of different molecule types in a piece of food. Getting a laser or series of lasers tuned to each type of molecule would be challenging. The fact that food is opaque and dense would likely be another problem.

Title: Re: Could we invent a
Post by: UltimateTheory on 29/12/2012 08:14:36

Quote from: Supercryptid on 30/07/2010 21:37:03

Laser cooling would be interesting, but given the way it works I don't see how it could be used on solid, chemically-complex objects like food. At least not in the immediate future. You have an awful lot of different molecule types in a piece of food. Getting a laser or series of lasers tuned to each type of molecule would be challenging. The fact that food is opaque and dense would likely be another problem.

That's easy- laser is cooling one particle, it's cooler than surrounding particles (especially those connected in solid body) whatever they are. Heat goes from hotter to cooler particles (photons jump between particles). And other particles that has not been hit directly by laser (or cooled any other way) are cooled too.

For example: put half of piece of metal to ice, even though second half is not in ice, it's cold.

Title: Re: Could we invent a \
Post by: syhprum on 30/12/2012 14:53:35

Provided the chamber was evacuated and the walls were cooled to near 0°K and were of radiation absorbing materiel the object that needed to be cooled would radiate away its heat in the form of Photons initially of infrared frequencies and as it cooled of progressively lower frequencies.

Title: Re: Could we invent a \
Post by: Santadiego on 19/01/2013 13:28:46

heat is how we measure the amount of motion in an atom. microwaves cause the atoms to vibrate faster.. heat up. a device to slow the vibrations down would be the opposite of a microwave. absolute zero is when there is no motion.