Instructions for microwave cooking usually say don't cook more than one item at a time. If I cooked two items (in flat containers), which is more efficient - stacking them vertically or placing them side by side?
I guess it would depend on how the microwaves are focused inside the oven and where the convergence point is? I don't know if having a rotating base would make any difference or not, though.
It takes 1 minute to heat 1 cup of water to boiling with a 1000 Watt microwave, but between 2-3 minutes to heat two cups, and almost 6 minutes to heat 3 cups, with or without a rotating base. Lower wattage microwave ovens will take correspondingly longer to heat equivalent amounts of liquid. Be careful! Heating may be uneven and the water may become superheated, which means, tapping on the side of the cup (because of the mechanical equivalent of heat) can cause near boiling water to explode violently out of the cup onto whatever is outside, which might include your face. A rotating base may help heat the water more evenly, but it does not eliminate the possibility. You can reduce the risk of this kind of injury either by heating it in a dirty cup, or by adding whatever it is you are making (instant coffee, cocoa, or whatever) before heating it.
It looks like your reply says that horizontal placement slows things down. What happens when the placement is vertical?
If I remember correctly, the fan in a microwave also acts as a reflector that chops the microwaves from the magnetron as it spins to spread the energy fairly evenly through the volume, but it would seem to mostly be near the center. The carousel helps with stuff that may or may not be evenly distributed in the heated volume. An experiment is in order! I'll use two 1-cup pyrex measuring cups with 1 cup of water in each, then one 2-cup pyrex measuring cup with 2 cups of water, and observe how long it takes for the water to boil in each set-up. There's gonna be a fudge factor (or a subjective call) in the case of two 1-cup beakers if the microwave energy is not spread evenly through the volume, and my microwave doesn't have room to stack two 1-cup beakers... I strongly suspect it'll work better vertically, but we won't know until I get a tall microwave and two people with stopwatches, or infrared thermometers. Or any of a number of other factors that make this argument less than scientific... Maybe one or two of y'all would like to help? Please Register or Log in to view the hidden image!
Pardon? Not to be obtuse, but with your Kirkegaard quote, I wonder what you meant. I'm serious, even if you aren't.
Some foods have a higher water content than others, so depending on the foodstuff in question being 'waved there may be a difference at which the microwaves are being absorbed by the material, which could make a noticeable difference in speed of heating when those foods are orientated horizontally or vertically? Is that what you meant? Please Register or Log in to view the hidden image!
In addition to a rotating base, many microwaves feature a "stirrer" to further rotate the microwave energy and eliminate any "hot spots". Vertical placement should not be substantially different from horizontal placement, but the time needed to heat something to a particular temperature is still related to its water content and quantity as well as placement / impedance matching within the microwave cavity. Some food packaging use melamine (a thermoplastic) inserts in order to effect browning of bread crusts. The melamine insert heats up and retains higher temperatures newest the part of the food to be browned. In all cases, you don't get more energy into the food than is provided by electricity to the magnetron (microwave transmitting element), and the speed with which that energy is transferred to things being cooked is dependent on the design and power (Wattage) supplied to the magnetron as well as the characteristics of the microwave cavity.
Home improvement supply stores like Hechinger used to sell home microwave leakage detectors. These still work just fine for checking the door seals of microwaves and I still have a few functional ones. They are very simple devices, basically an antenna, a microwave diode, and a meter movement. When it indicates in the red zone, the emission of the microwave is exceeding 10 mW/cm^2. These devices also used to work on old analog cellphones, like the Nokia model I briefly owned that was also owned by the late Johnny Cochran (of the infamous O.J. Simpson trial). Cochran died of a brain tumor located nearest to the ear he used with his Nokia cellphone, a cause of death almost unheard of before the appearance and proliferation of the devices. O.J. Simpson was evidently not guilty of the murder, but went to trial to cover up a murder evidently committed by his son, who was never charged. Johnny Cochran's law firm, which survives to this day, was not able to win a case against Nokia for their dangerous analog cellphones, even though Motorola had already lost many dozens of such lawsuits related to the microwave emissions of similar devices. The simple devices used to check microwave ovens no longer work with modern cellphones because these typically use sophisticated spread spectrum technology to rotate the microwave signals faster than the microwave diodes can rectify them. However, there is no longer any need for concern about the radiation dangers of these devices because complaints from knowledgable folks like yours truly eventually convinced them to remove the transmit antennas from locations closer to users's ears to somewhere near their mouths. The trend before this engineering change was to make the devices as small as possible (smartphones are clunky by comparison), and this fact led to many colorful online and offline discussions between yours truly and younger engineers with anchors for grey matter and a death wish for users of their dangerous devices. The conversation I started with the then President of the IEEE regarding cellphone safety likewise proved fruitless. The engineering committees of the IEEE in their effete wisdom decided it was best to change a precise maximum intensity specification of 10 mW/cm^2 to a much more difficult to measure calorimetry (Specific Absorption Rate) specification of 1.6 Watts / kilogram. Basically, this SAR specification is measured with a thermometer immersed in a vessel of brake fluid the shape of a human head. All of this was done by committee at the IEEE in order to allow the cellphone industry to flourish without the legal hassle of defending the safety of devices that was initially very, very poor. Although I am still a member of IEEE, the experience left me with little regard for the efficacy of science or engineering done by means of a committee, and a similar disdain for the old saw about anecdotal medical evidence ("correlation is not causation") promoted by the American tobacco industry in the 1940s. Anecdotal evidence may not be good enough for medical research when millions of lives are at stake, but more often than not, somehow whenever a lot of money is at stake, all of those lofty medical ideals go unceremoniously out of the nearest window. When used properly and according to instructions, microwave ovens and cellphones are safe and effective. Tobacco products are not. Placebos, quackery, and bad engineering are not worth quite as much money, but are not good for your health either. The moral of the story: keep the microwave oven door closed while it is operating and do not attempt to defeat the provided interlocks. Do not attempt to make diamonds out of peanut butter in a microwave. Do not leave forks or other metal utensils inside of the microwave oven or inside of dishes of food you try to heat there, and of course, don't try to microwave items in metal dishes. All of these items will produce corona discharges and detune the microwave cavity, which will probably produce dangerous substances as well as damage the magnetron. 1000 Watts is too much energy to play around with if you don't understand what you are doing. Bon Appetit!
*blink* Do any modern microwaves operate without the door being closed? I mean, sure... if you stick something into the switch to simulate the door being shut, the fine... but why the hell would one want to do that?
Kids sometimes do such things apparently because they can. Anyone with a hammer and hacksaw could inflict such damage to a microwave door and themselves if they were determined enough. Doing so, they will likely suffer eye damage first, because exposure to microwave energy can cause premature cataracts and other damage to soft tissue like the blood-brain barrier. This was the main reason for the microwave leakage home detector kits I mentioned. Premature cataracts was the subject of an early lawsuit against Motorola from a user of one of their analog microwave walkie-talkies, a lawsuit which they lost to the tune of about 4 million dollars, a large penalty at the time. Cataracts were not nearly so easy to treat back then as they are now. And using one of their microwave walkie-talkies was very much like operating a microwave oven with the door open. These are things the cellphone industry would like you to forget about. Maybe we need a microwave oven that uses spread spectrum technology at a lower energy so that it's harder to detect a damaging amount of radiation. Just kidding. That would wipe out the cellphone industry in a hurry though. Watching all those videos about making diamonds from peanut butter in a microwave might encourage this behavior for all I know. Why does every young person think they will learn all about computers by fumbling half working ones together in their garages? It rarely works out like Apple computer. Same reason radioactive boy scouts are now building fusors in their basements is my guess. I wouldn't want to be their neighbor. I was young once, and barely survived it. One should never underestimate the power of stupidity.
Well, heck, if they are going to hack at their microwaves with a hacksaw, they're much more likely to electrocute themselves first. (Or cut themselves to ribbons on the sharp edges.)
But again, they will do all that, but then reassemble it and power it on with the magnetron pointed at them? In any case, if their choice is to try to defeat the interlocks and radiate themselves, or to lie in the sun for an hour, they are much better off (from a cataract/cancer/radiation sickness perspective) messing around with the microwave. They might be exposed to radiation - but unlike lying in the sun, it is not ionizing radiation.
So what? Boiled eyeballs or lymphatic cancer as a choice? Stupid is stupid, and shouldn't necessarily be prevented from culling the herd.
Well, skin cancer or thermal burns are a more likely choice. (Obviously "none of the above" is a better choice.)
