Science of Microwave Ovens (2016)

https://www.genuineideas.com/ArticlesIndex/wave.html

by comebhack • 1 year ago

75 61 1 year ago

bell-cot2• 1 year ago

(2016), FWIW.

The article doesn't mention issues with putting metal - dishes, silverware, twist ties, whatever - in the microwave. IF you know what you're doing, that's pretty harmless. (If not - sparks, fire, and other excitement often results.)

lawgimenez• 1 year ago

Especially don’t forget to remove aluminum foils, sparks inside the microwave is a scary sight to witness.

newfocogi• 1 year ago

I understand the physics of microwaves but haven't taken the time to understand when metal is dangerous — I tend to just always avoid it.

Do you know of any resources that explain what scenarios belong in the "harmless" category?

cstrahan• 1 year ago

My (limited) understanding is that the shape is a large factor. Something about sharp edges or points concentrating the electric field induced by the microwaves, leading to a high voltage buildup. So forks are a bad idea, while spoons will likely not result in any sparks.

EvanAnderson• 1 year ago

Optical disks produce fun, brief light shows in the microwave. Don't run them for more than a couple of seconds, though.

dole• 1 year ago

Alton Brown used to have a recipe (I'm Just Here for the Food?) for homemade microwave popcorn where you can use a typical metal staple and it won't spark, something to do with the amount of metal, and also actual size of the microwave wavelengths used being bigger than a staple, iirc.

bell-cot2• 1 year ago

Good memory! He also says to use a turntable microwave, to keep the staples several inches apart, and away from the microwave's walls.

kbouck2• 1 year ago

ElectroBOOM demonstrates this:

https://youtu.be/OyTmJX_TC84?feature=shared

foobarian2• 1 year ago

jinx

foobarian2• 1 year ago

Yeah, Mr. ElectroBOOM has a pretty informative video [1] trying a handful of different configurations of metal objects in a consumer microwave oven. Turns out it's hard to make "interesting" things happen with metal even if you intend to.

[1] https://www.youtube.com/watch?v=OyTmJX_TC84&ab_channel=Elect...

edoceo• 1 year ago

Put a burning candle in there

https://www.experts-exchange.com/questions/24081775/Candle-i...

JoeDaDude• 1 year ago

I read somewhere that you can place a candle under a bowl (with allowance for oxygen to get in) and you can capture the plasma given off by the candle. https://www.youtube.com/watch?v=x5BFIVDUQPE

jurgenaut23• 1 year ago

I cannot read this title without my brain bringing back memories of 30 Rock

Cheer21712• 1 year ago

This last part is such pseudoscience that it makes me suspicious of everything I was nodding along with before:

Of the 70,000 chemicals in widespread commercial production, only around 500 have been competently screened for human toxicity. Since most products are a blend of numerous ingredients, it is axiomatic that all products contain at least one ingredient that is untested and not known to be safe. This includes everything from hand lotion to plastic water bottles to deoderizers.

whycome• 1 year ago

at least one ingredient that is untested and not known to be safe

This seems kinda okay though. It’s very different to saying “known to be unsafe”. There are tons of untested (or insufficiently tested) things.

Cheer21712• 1 year ago

Do you not understand what the word axiomatic means? If there are 70,000 chemicals and only 500 have been tested, does that mean *every single product* *must* contain an untested ingredient? No, because products don’t randomly pull ingredients out of a hat. Proof by counterexample: pure water in a bottle made of the many materials that have been tested for food safety. But hey, why bother with facts when you can just make shit up and call it "axiomatic"?

Words have meaning.

KineticLensman• 1 year ago

My father was a radar officer in WWII, and recalled warming his hands on cold British mornings in front of the beam emitted by a "magnetron" inside his primitive radar transmitter. Then he went back to work detecting Nazi aircraft. But, it is a short distance from warming to cooking- in 1946 engineers at the military contractor Raytheon noticed microwaves could not only warm, they could heat and cook food.

In the 1990s I was a contractor at DRA Malvern in the UK, which was one of the successor organisations to the WW2 radar research establishments. The greybeards I encountered always felt that they had invented microwave cooking even if Raytheon got the credit later. Sausages cooked using the lab magnetrons, they said, although unfortunately there were no photographs.

The future of cooking was something that famous futurist Arthur C Clarke got wrong. He might have predicted geostationary communications satellites but in his short story The Sentinel - which was the inspiration for the film/book 2001 - the crew of a small lunar rover fry their sausages in a conventional frying pan.

anotherhue• 1 year ago

You can put some thermal paper, or a sufficiently large chocolate bar in there (without the turntable) to see the interference patterns yourself without any fancy gear.

You can then eat the chocolate.

nimbius• 1 year ago

processed cheese will visualize the waveform well.

rhodescolossus• 1 year ago

I wonder if there’s a market for a microwave with an IR camera and AI to estimate food weight and thermal conductivity.

With accurate heat tracking, it’d only need a button to open the door and no knobs.

ssl-34• 1 year ago

We can measure weight using a scale.

We can make a solid guess at volume using visible light and a rotating view (already provided by the unfortunately-common carousels), with a bit of CV and math.

We can therefore deduce density.

We can measure outside temperature using IR.

And we can measure the power put into the things being microwaved.

And we can also measure the temperature and humidity of the air that is exhausted from the microwave chamber.

With all of that data, we can do some cool things.

But with only single-button input, there's a lot we can't do:

We can't know if the user is cooking a hamburger from raw meat (yes, raw meat can be used in the science oven), or reheating one that was already cooked, or finishing one that was par-cooked.

We can't know if they're softening butter to spread onto toast, or melting it to pour over popcorn

We can't know lots of things. So we need more than one user input.

The slope to getting back to where we started is very short: Some preset buttons that most people will never understand, a speed control that most will never use, and a keypad for a timer.

SoftTalker• 1 year ago

Agree. I think 90% if people use their microwave to reheat leftovers or cook pre-packaged meals. All they need is a timer. And I'd prefer a dial to a keypad.

My wife bought a countertop convection oven that has nearly 100 pre-defined cooking programs and 10 different "quick set" buttons. How do we actually use it? Set a temperature and time. With a dial. Could have be so much simpler.

crazygringo5• 1 year ago

I want an IR camera and I want to input my desired temperature. That's all.

Then I want the microwave to cycle on when the camera says everything is below temp, and cycle off as soon as any hot spot hits temp. Then wait for the hot spot(s) to dissipate before cycling back on.

Seems like a foolproof way to cook evenly without overcooking.

I kind of approximate it now by cooking something frozen on high for a couple minutes, then on 20% power for five minutes, then 10% power for another five minutes. But it would be nice to have it all automated.

01100011• 1 year ago

When I was a kid(~1980), I remember our microwave had a removable temperature probe you could insert into the food. I don't know if it was just for informative purposes or if it controlled the cooking however.

glitchc3• 1 year ago

The only problem is that the camera would not survive the first time you use that oven. High power microwaves happily destroy all manner of electronics.

snarfy• 1 year ago

If it's going to take 10+ minutes to cook, why not use something like a toaster oven?

MisterTea2• 1 year ago

I know someone who worked at a failed startup that attempted almost exactly this minus the AI. It used an IR camera paired with a secret method to beam form the microwaves to uniformly heat the food no matter how it was dispersed across a plate. This means you could have a pile of water rich vegetables and a steak on a plate and it would heat evenly. It worked great nut IIRC the issue that caused it to fail was calibration of the IR sensor took a ton of effort and they could not scale that to a production scenario. Edit: should mention it let you dial in a temperature so the method is workable, just needs to scale to production.

FuriouslyAdrift2• 1 year ago

This one?

https://www.eater.com/2015/2/11/8022235/never-burn-popcorn-a...

xp843• 1 year ago

Wow. I envy the guy who got to take the prototypes home. What a device that would be to have in your kitchen!!

FuriouslyAdrift2• 1 year ago

From all the way back in 2015 https://www.eater.com/2015/2/11/8022235/never-burn-popcorn-a...

HPsquared• 1 year ago

IR sensors aren't reliable if there is a lot of water vapour coming off the food (it measures the temperature of the water vapour). Great for oil and other dry heat (but again beware, with shiny metal they tend to measure the mirror image of what's reflected by the metal, not the metal itself). These effects are more visible using an actual thermal camera.

Terr_• 1 year ago

Some microwaves take a useful shortcut with a sensor for water vapor, so they know when something has started to steam and can reactively change the amount of time remaining.

Obviously this is great for things like soups, but not-so-much for things which don't reach 100C in an even fashion.

NotYourLawyer• 1 year ago

Better microwaves existed. Nobody wanted them. Technology Connections:

https://www.youtube.com/watch?v=UiS27feX8o0

xp843• 1 year ago

If even one person here doesn't yet have a fast-reading food thermometer I have to evangelize for them here. Good ones that instantly read used to cost like $75, and the cheap kind would take literal minutes to arrive at the real temp, but I think someone in China figured out the secret and brought the price down to like $14. Mine has a magnet and I keep it right next to the microwave and air fryer. It has made it tremendously easier to get food correctly heated through, in both devices.

The other thing I believe in strongly is, for most things, using 40-60% power and heating the food about twice as long as your original instincts say, for more even heating.

copypasterepeat• 1 year ago

Completely agree with the reduced power recommendation. That really helps evenly heat foods that start popping in the microwave or have hot spots when taken out. The few extra minutes are usually not a big deal anyway.

Scubabear68• 1 year ago

In particular, anything that has a lot of liquid benefits from using lower power for longer.

Of course, putting a quart of spaghetti sauce in an open container and microwaving it at 100% will result in some very cool sauce explosions as localized steam in the source rapidly expands and blows giant sauce bubbles all over your microwave.

Projectiboga• 1 year ago

Yes microwaves can go far through ice but only 15 or less milimeters into water depending on the water's temperature. Microwaves are best for ready to eat frozen foods or reheating leftovers spread out over a plate.

wholinator2• 1 year ago

Yeah, the instant thermometers are very nice. Also though, i was recently asked about my favorite nonstandard kitchen appliance and my laser thermometer is my single favorite kitchen gadget, i use it every single time i cook anything. Granted, it reads the surface, but it'll tell you the exact temperature the skillet is at , at every location so you can tell when the cast iron is sufficiently heated to perfect a steak. I prefer my food at about 120°F which is right around the steam point.

Also interesting point related to the article, if i point my laser thermometer at the microwave while it's going it'll bug out and return random temperatures between the actual temperature of the window and about 500°F. I'm sure i could figure out why but i just haven't had the time yet

anotherevan• 1 year ago

Our microwave oven died on Christmas Eve, and I ended up getting one of those newer flatbed ones. The novelty of putting something in there and watching it not rotate has not worn off yet.

beloch2• 1 year ago

If you're screwing around with microwave sources, I'll pass on a warning I got from one of my profs.

Microwaves will heat your body up, but in a relatively harmless way. e.g. If you microwave your hands a bit, blood flow will transfer that heat out and things will remain pretty okay unless you really overdo it.

Your eyes are an exception. They're orbs of aqueous humor that's mostly water, but have relatively little blood flow when compared to most other tissues in the body. Microwaves will heat them up, but bloodflow won't distribute the heat away quickly. Protect your eyes around microwave sources.

agumonkey• 1 year ago

What kind of protective goggles can help here ?

beloch2• 1 year ago

No idea. What the prof meant was to avoid exposure. i.e. Maybe don't lean in so close to get a better look at it while it's on.

chiph• 1 year ago

If anyone has a school-age child needing a science experiment, my niece created a list of various items and what she expected their behavior to be in a microwave at different cooking times.

And then tested her hypothesis in a cheap microwave (out in the yard in case of explosions), documenting what happened with photos and making a conclusion for each. She got top scores from the teacher for following the scientific method.

craigmcnamara• 1 year ago

Put a whole uncooked egg in the microwave for a few minutes and call me in the morning.

Science of Microwave Ovens (2016)

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