The Opposite of a Microwave?

I believe I understand the basic principals on how a microwave can heat up your food (or a cat) so fast, but would it be possible to create a device that does the opposite. In essence, something that could decelerate the vibration of molecules so you could cool food (or your cat) down just as fast as a microwave?

I realize if such a device ("Macro"wave?) were possible and reasonably practical to build, we would see it on the consumer market… so why don’t I have one next to the fridge?

Generally, you don’t need to get things cold fast in your house. A portable one would be nice for the beach, though.

Indeed, you can cool things with laser cooling which is somewhat similar to microwave heating in that it uses part of the electromagnetic spectrum to change the thermal properties of the matter that it’s operating on. However, right now such devices are well out of your price range and not available for general commercial use.

The “MACRO” wave idea is cutesy, but scientifically inaccurate. The reason it’s called “microwave” is because the wavelength of the electromagnetic radiation used is smaller than the radiowaves we’re all used to (about a micron. You might, in fact, think of it as exciting tiny little antennas that we call water molecules to heat your food up. Any laser cooling would be done with highly attenuated beams which would mean that the wavelengths would be even smaller than what you find in your microwave oven.

Yeah but … in order to cool a roast down as fast as a microwave heats it up, the laser would have to penetrate all through the roast so as to be bouncing off all the vibrating parts more or less at once. If it just operated on the surface of the roast, the conductivity of the meat would slow the process down just like the time it takes a conventional oven to heat things up.

A microwave heats things because it penetrates through the roast, or whatever, and is coupled to the charges inside. So the energy of the microwave tube is carried by the wave directly to the charges, causing them to vibrate and thus heat the material around them almost simultaneously throughout the roast.

In order to do the same with cooling you would have to have some sort of penetrating antenna that could couple to and abstract the energy from the vibrating charges all through the roast and then transmit that energy outside the cooling chamber to some sort of radiator

I don’t see any way to do it.

On the other hand … a MASER is the microwave equivalent of a LASER. In fact it was invented first and I believe the early LASERS were called OPTICAL MASERS.

In any case, maybe something along the lines of a LASER cooler could be developed using MASERS and that radiation would, or could, penetrate the meat.

Someone with a strong scientific ability, like JS Princeton, might become a millionaire with this. Provided there is a market for such a device.

The short answer is that it’s a lot easier to add energy to a system (in this case heat) than it is to remove it.

I’d love one. Your pop and beer could be as cold as desired the moment you brought it home, of course puddings could be finished quicker…

Thanks for the vote of confidence, but I’m going to have to side with your first opinion. Basically, the problem as I see it isn’t penetration, but the reflection of the beam. You have to hit your particles just right in order to slow them down (it’s basically an inelastic collision). Then you have to make sure your reflected beam doesn’t get absorbed by any other part of the system you’re trying to cool.

With a well ordered system, like Helium nuclei, that’s a lot easier to do than with a bizarre system like a turkey. Even then, it wasn’t until a relatively short time ago that we could do laser cooling on Helium nuclei with any sort of efficiency. However, a fast and furious laser freezer may not be necessarily beyond the realm of possibility. Clearly more research is required.

For now, you might as well use liquid nitrogen. Unfortunately, it’s a bit expensive and requires delivery, but it’ll cool your beer down nice and quickly. May crack the receptical it’s in too, though, I’m afraid, not as discriminating as the “MACRO” wave idea.

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–on the sidelines–

I can just see in thirty years the inventor of the commercial laser cooling device being interviewed on the Today Show,

“While a microwave warms things up; your invention cools things down. Would you say it would be fair, then, to call your new device a MACROwave?”

>> How does a very small man say goodbye?

>> With a micro wave

No, no, you’d call it a microFREEZE.

At least that’s what I called it when I thought this up years ago. Except all my engineer friends told me it couldn’t be done, so I didn’t go get a patent or anything.

And of course it would be useful. I was thinking of making ice quickly. Or when people show up for a party… you need ice and cold drinks now, not in 30 minutes…

Actually, microwave ovens are usually somewhere around 2.5 GHz or the 10 cm area. Much larger than a micron wavelength.

I think you are well into the infrared by the time the micron is a useful wavelength measure.

If microwave were really micron scale wavelengths, it would zip right through that metal screen behind the glass (the whole would be too big). The same reason that light goes right through it.

whole… hole… or even holes would have been better.

Great responses everyone!

I seem to recall a T.V. show (perhaps “Invention”) did a story about the making of the first microwave. How it cost IIRC $100,000 to build. Perhaps if enough research and mass production went in to the invention, it would come way down in cost just like the microwave (and just about every other electronic device).

Also, would the Laser/Maser be harmful if used on humans (or cats)?

Obligatory link to the Jet-Powered Beer Cooler. (A former Weird Earl’s).

There is actually a sort of “reverse microwave” for industrial applications…except that it uses plain old cold air instead of exotic radiation. It’s called a blast freezer or an IQF (Instant Quick Freeze) system. Basically just a souped up refrigerator with huge evaporator coils and great big fans to move a lot of cold air. It often incorporates a conveyor belt, either straight (freeze tunnel) or spiral.

They can cool things damn quickly, but they’re not exactly suited for household use.

I would be suprised if it cost anywhere near $100,000 to build. The power source in a microwave oven is pretty much an off the shelf radar part. The R&D should have been pretty limited, build a metal box and use a radar amplifier to fill the box with radio waves. After that, it is just getting it ready for consumer use. (If you remember, the early microwave ovens were called “Radar Ranges”, maybe some still are).

As to harmful. Anything that can quickly add or remove energy from a living organism will be harmful more than likely.

A high powered radar can pop (literally make them explode) birds that fly through the beam close to the antenna. One of the old radars that I worked on put out 3.2 million watts in a “pencil beam” format. There is no first-aid for getting into that beam.

Thanks for the correction, scotth. I don’t know where my brain went on that one. The micron is roughly the wavelength where visible light ends and infrared begins. Of course, you can still measure microwaves in microns, it is just in thousands of microns instead of a single micron.

Those orders of magnitude will getcha every time!

Check this out:

http://www.gallawa.com/microtech/history.html

It doesn’t say anything about how much the R&D cost, but it does say that the first commercial MW’s were around $5000. Crazy.

Get yourself a tank of liquid nitrogen.

Speaking of the history of the microwave oven, I recall seeing Anita Bryant advertise the Amana Radarange (I was in high school), and when she would put her hand in the oven and actually touch the insides of an oven that had been operating, I thought that was trick photography.

You don’t offer too many that need big corrections that I have seen.

After spending 8 years as a radar tech, that one pretty much jumped off the page at me, though.