How does a microwave oven heat food?

How does a microwave oven heat food?

A microwave oven uses a vacuum tube called a magnetron to create intense microwaves inside the cooking chamber. These microwaves are electromagnetic waves with a frequency of 2.45 gigahertz or 2,450,000,000 cycles per second. They are similar to normal radio waves, except that they have a higher frequency. Because of these microwaves, the electric field at any point inside the cooking chamber fluctuates back and forth 2.45 billion times each second. That means that an electrically charged particle at any point in the cooking chamber will be pulled first one way and then the other, back and forth 2.45 billion times each second. While water molecules aren’t electrically charged overall, they do have electrically charged ends—one end is positively charge and the other is negatively charged. In the presence of the microwave radiation, these water molecules find themselves twisted back and forth very rapidly. As they twist, they rub against one another and friction heats them up. The water becomes hot and this hot water, in turn, cooks the food. Food that doesn’t contain water (like salt or oil) won’t get hot. Neither will food in which the water molecules can’t turn (like ice or frozen food). That’s why it’s hard to defrost frozen food in a microwave.

Does microwave cooking break molecular chains? Does any recombination of ions ta…

Does microwave cooking break molecular chains? Does any recombination of ions take place in the food and, if so, is there a possibility of eating some type of toxin formed during cooking?

The answers to all of these questions are no. Microwave cooking merely heats the water molecules, which in turn heat the food. The only molecular rearrangements that occur are those that are caused by warming the food toward the boiling temperature of water. In fact, there is less chemistry done during microwave cooking than is done in a normal oven. For example, one of the problems with microwave cooking is that food doesn’t brown because the high temperatures needed to chemically modify the food molecules (and cause browning) aren’t reached in microwave cooking. So you shouldn’t have any fear of food cooked in a microwave oven. The microwaves don’t damage it any more than heating it in boiling water would.

How does an integrated circuit store so much information?

How does an integrated circuit store so much information?

An integrated circuit is formed by using photographic techniques to sculpt the surface of a silicon crystal, to add chemicals to the silicon, and to deposit layers of other materials on top of the silicon. As part of this sculpting and coating process, a typical computer chip will have tiny memory cells formed on it. These cells usually consist of a tiny pad of aluminum on which a small amount of electric charge can be stored. To store one piece of information, a “bit”, on one of these pads, electronic devices called MOSFETs—built right into the silicon surface—are used to control the flow of charge onto the pad. The amount of charge on the pad determines the bit’s value. The charge remains on the pad, thus storing the bit, until it’s time to recall the bit. At that time, the MOSFETs allow the charge to flow off the pad and into electronic devices that determine what the stored value is.

Can magnetic energy be used to power a vehicle?

Can magnetic energy be used to power a vehicle?

When you talk about “magnetic energy,” you are referring to magnetic potential energy. A potential energy is energy stored in the forces between objects. In the case of magnetic potential energy, that energy is stored in the forces between magnetic poles. But there is only so much potential energy in any given collection of objects. Potential energy is released by allowing the forces between objects to push the objects around and once it is used up, there isn’t any more available. That’s because energy is a conserved quantity—something that can’t be created or destroyed and that can only be transferred between objects or changed from one form to another. While you can store energy in a collection of magnets, that potential energy is limited by how much was put in in the first place. So to answer to your question: yes, magnetic energy can be used to power a vehicle, but not indefinitely. The only practical magnetic energy storage proposals I’m aware of are ones that suggest using huge superconducting magnets to store electric power. While such devices might be practical for an stationary power company, they would be impractical or even dangerous in a vehicle—picture cars containing incredibly strong magnets driving down the road, repelling or attracting one another as they pass.

How can I differentiate between daylight and incandescent light?

How can I differentiate between daylight and incandescent light?

Actually daylight is a form of incandescent light. Incandescent light is the thermal radiation emitted by a hot object such as the filament of a light bulb or the surface of the sun. But the spectrum of incandescent light emitted by an object depends on its temperature. Since the filament of an incandescent light bulb has a temperature of only about 2500° C, its light is much redder than the light emitted by the 6000° C sun. That’s why photographs taken indoors with incandescent lighting turn out so orange—the light just isn’t white, it’s orange-red. So you can differentiate between sunlight and the light from an incandescent bulb by comparing the spectrums. Look for the relative intensities of red, green, and blue lights. Sunlight will have much more blue in it than light from an incandescent bulb.

Does everything (all matter) emit radiation? What about if something is at absol…

Does everything (all matter) emit radiation? What about if something is at absolute zero? What about if it’s inside a black hole? Does a black hole emit radiation? Are Hawking particles emitted by the black hole or are they spontaneously created? If a black hole causes particles to be created, is that the same as the black hole emitting them?

To begin with, matter always emits radiation. That’s because, at any temperature above absolute zero, the electrically charge particles in matter are in thermal motion and they accelerate frequently. Any time an electrically charged particle accelerates, it emits electromagnetic radiation. If you could cool matter to absolute zero, the thermal motion would vanish and the matter wouldn’t emit radiation. However, absolute zero is an unreachable destination—it can’t be achieved—so everything experiences thermal motion and emits radiation.

The issue of radiation emitted by a black hole is another story. For decades, people thought of a black hole as perfectly black—it absorbed radiation perfectly but emitted none itself. However, Stephen Hawking showed that a black hole does emit radiation and that it behaves like a normal blackbody: an object that emits thermal radiation characteristic of its temperature. The temperature of a black hole is inversely proportional to its mass. For black holes of any reasonable size, this temperature is so extraordinarily low that the black hole emits very little Hawking radiation.

This radiation originates in the vicinity of the event horizon, the surface inside which the black hole’s gravity finally becomes strong enough to prevent even light from escaping. At that surface, quantum fluctuations in which particles are temporarily created and destroyed can occasionally lead to the creation of a particle that escapes the black hole forever. In effect, two particles are created simultaneously, one of which falls into the black hole and is lost and the other of which escapes forever. The particle that falls into the black hole actually decreases the mass of the black hole, and the missing mass escapes with the other particle. As for whether the black hole causes this emission or is actually doing the emission, there is no difference. The only feature that the black hole has (other than electric charge and angular momentum) is its event horizon (actually a characteristic of its mass). If the event horizon is causing the particles to be created, then the black hole itself is at work creating those particles.

If you apply the brakes while making, say, a left turn on a motorcycle, the moto…

If you apply the brakes while making, say, a left turn on a motorcycle, the motorcycle will tend to “stand up.” That is, it will tend to fight the lean you make into the turn. Why?

When you turn left, you are accelerating toward the left and your velocity is changing toward the left. This leftward acceleration requires a leftward force and that force is supplied by friction between the ground and the motorcycle’s wheels—the ground pushes the wheels toward the left. However, this leftward force on the wheels also exerts a torque (a twist) on the motorcycle about it’s own natural point of rotation—its center of mass. As the ground pushes the wheels toward the left, the motorcycle tends to begin rotating. In this rotation, the wheels begin moving toward the left and the driver’s head begins moving toward the right—the motorcycle “stands up”! Actually, if you lean far enough to the left as you turn, an opposing torque due to the upward force that the road exerts on the wheels will balance the first torque and your motorcycle will experience no net torque—it won’t stand up at all. On a high-speed turn, you must lean quite a bit to avoid the “standing up” problem, which is why motorcycle racers practically touch the ground as they turn.

About 18 months ago, I saw an episode on “Current Affairs,” in Australia, in w…

About 18 months ago, I saw an episode on “Current Affairs,” in Australia, in which this dude made a “free electricity” machine, using magnets, fixed and non fixed-on a spinning wheel. While I know that I should be skeptical, I can’t help thinking “what if?” Have scientists carefully tested this stuff to see for sure that it does or does work? – P, Australia

Not surprisingly, no “free electricity” machines are ever released to real scientists for testing. That’s because the results of such testing are certain: those machines simply can’t work for very fundamental and incontrovertible reasons.

Like so many “scientific” conmen, the purveyors of this particular scam claim to be victims of a hostile scientific establishment, which refuses to accept their brilliant discoveries. They typically attack the deepest and most central tenets of science and claim that a conspiracy is perpetuating belief on those tenets. Their refusal to submit their work to scientific peer review is supposedly based on a fear that such review will be biased and subjective, controlled by the conspiracy.

The sad reality is that the “scientific establishment” is more than willing to examine the claims, but those claims won’t survive the process of inspection. In some cases, the authors of the claims are truly self-deluded and are guilty only of pride and ignorance. But in other cases, the authors are real conmen who are out to make a buck at public expense. They should be run out of town on a rail. >

Click here for more information about the “free electricity” hoax, sent in by readers of this site.

There is a story circulating by email about a 26 year old man who heated a cup o…

There is a story circulating by email about a 26 year old man who heated a cup of water in a microwave oven and had it “explode in his face” when he took it out. He suffered serious burns as a result. Is this possible and, if so, how did it happen? — JJ, Kirksville, Missouri

Yes, this sort of accident can and does happen. The water superheated and then boiled violently when disturbed. Here’s how it works:

Water can always evaporate into dry air, but it normally only does so at its surface. When water molecules leave the surface faster than they return, the quantity of liquid water gradually diminishes. That’s ordinary evaporation. However, when water is heated to its boiling temperature, it can begin to evaporate not only from its surface, but also from within. If a steam bubble forms inside the hot water, water molecules can evaporate into that steam bubble and make it grow larger and larger. The high temperature is necessary because the pressure inside the bubble depends on the temperature. At low temperature, the bubble pressure is too low and the surrounding atmospheric pressure smashes it. That’s why boiling only occurs at or above water’s boiling temperature. Since pressure is involved, boiling temperature depends on air pressure. At high altitude, boiling occurs at lower temperature than at sea level.

But pay attention to the phrase “If a steam bubble forms” in the previous paragraph. That’s easier said than done. Forming the initial steam bubble into which water molecules can evaporate is a process known as “nucleation.” It requires a good number of water molecules to spontaneously and simultaneously break apart from one another to form a gas. That’s an extraordinarily rare event. Even in a cup of water many degrees above the boiling temperature, it might never happen. In reality, nucleation usually occurs at a defect in the cup or an impurity in the water—anything that can help those first few water molecules form the seed bubble. When you heat water on the stove, the hot spots at the bottom of the pot or defects in the pot bottom usually assist nucleation so that boiling occurs soon after the boiling temperature is reached. But when you heat pure water in a smooth cup using a microwave oven, there may be nothing present to help nucleation occur. The water can heat right past its boiling temperature without boiling. The water then superheats—its temperature rising above its boiling temperature. When you shake the cup or sprinkle something like sugar or salt into it, you initiate nucleation and the water then boils violently.

Fortunately, serious microwave superheating accidents are fairly unusual. However, they occur regularly and some of the worst victims require hospital treatment. I have heard of extreme cases in which people received serious eye injuries and third degree burns that required skin grafts and plastic surgery.

You can minimize the chance of this sort of problem by not overcooking water or any other liquid in the microwave oven, by waiting about 1 minute per cup for that liquid to cool before removing it from the microwave if there is any possibility that you have superheated it, and by being cautious when you first introduce utensils, powders, teabags, or otherwise disturb very hot liquid that has been cooked in a microwave oven. Keep the water away from your face and body until you’re sure it’s safe and don’t ever hover over the top of the container. Finally, it’s better to have the liquid boil violently while it’s inside the microwave oven than when it’s outside on your counter and can splatter all over you. Once you’re pretty certain that the water is no longer superheated, you can ensure that it’s safe by deliberately nucleating boiling before removing the cup from the microwave. Inserting a metal spoon or almost any food into the water should trigger boiling in superheated water. A pinch of sugar will do the trick, something I’ve often noticed when I heat tea in the microwave. However, don’t mess around with large quantities of superheated water. If you have more than 1 cup of potentially superheated water, don’t try to nucleate boiling until you’ve waited quite a while for it to cool down. I’ve been scalded by the stuff several times even when I was prepared for an explosion. It’s really dangerous.

For a reader’s story about a burn he received from superheated water in a microwave, touch here.

I recently read a full-page ad for FREE ELECTRICITY from a company called United…

I recently read a full-page ad for FREE ELECTRICITY from a company called United Services Company of America. Their Website is at http://UCSofA.com/Free%20Electricity.htm. I walked through their site and viewed some of their videos “demonstrating” clear violations of the well-known and well-founded Laws of Thermodynamics, and listened to the description of the new Fourth Law of Motion (following Newton’s other well known three). Are these people the same who were denied patent approval for a Perpetual Motion Machine? Have any reputable independent test labs reviewed their products under controlled conditions? Do they publish, even at a price, the fundamental mathematical and physical processes that allow for the claims that seem to be shown? I realize you’re not a “debunker”, but maybe you can shed some light on this. They have scheduled dozens of seminars across the country at considerable cost (and most likely considerable profit to them), and taken out full-page ads in national newspapers. The speakers do not comment on their academic training or experience, but tend to speak of hidden conspiracies from the power industry to stop their proliferation of free power. — DH

What a great find! This site is filled with pseudo-science at its best. I don’t know the history or training of these people, but it’s pure garbage. They use the words of science but without any meaningful content. Just as putting on a crown doesn’t make you a king, using phrases like “action and reaction” and “Newton’s third law” doesn’t mean that you are discussing real science.

I watched the video on the “Counter Rotation Device” and found the discussion of “Newton’s Fourth Law of Motion” quite amusing. The speaker claims that this fourth law was discovered about 30 years ago by a person now at their research lab. It is based on Newton’s third law, which the speaker simplifies to “for every action there is an equal and opposite reaction.” In a nutshell, his fourth law claims that you can take the reaction caused by a particular action and apply it to the action in the same direction—action causes reaction which causes more action which causes more reaction and so on. Pretty soon you have so much action and reaction that anything becomes possible. The video goes on to show devices that yield more power than they consume and that can easily become net sources of energy—by using part of the output energy from one of these energy multiplying devices to power that device, you can create endless energy from nothing at all.

Sadly enough, it’s all just nonsense. Newton’s third law is not as flexible as the speaker supposes and this endless feedback process in which reaction is used as action to produce more reaction is ridiculous. A more accurate version of Newton’s third law is: “Whenever one object pushes on a second object, the second object pushes back on the first object equally hard but in the opposite direction”. Thus when you push on the handle of a water pump, that handle pushes back on you with an equal but oppositely directed force. The speaker’s claim is that there is a way to use the handle’s push on you as part of your push on the handle so that, with your help, the handle essentially pushes itself through action and reaction. You can then pump water almost without effort. Sorry, this is just nonsense. It’s mostly just playing with the words action and reaction in their common language form: if you scare me, I react by jumping. That action and reaction has nothing to do with physics.

The speaker uses at least three clever techniques to make his claims more compelling and palatable. First, he refers frequently to a power-company conspiracy that is out to destroy his company and its products. Conspiracy theories are so popular these days that having a conspiracy against you makes you more believable. Second, he describes the fellow who discovered the fourth law of motion as a basement inventor who has taken on the rigid scientific establishment. Ordinary people love to see pompous, highly educated academics brought low by other ordinary people; it’s kind of a team spirit issue. And third, he makes casual use of technical looking equipment and jargon, as though he is completely at ease in the world of advanced technology. Movies have made it easier to trust characters like Doc Brown from “Back to the Future” than to trust real scientists.

In fact, there is no power-company conspiracy because there is no free electricity. The proof is in the pudding: if these guys really could make energy from nothing, they’d be doing it every day and making a fortune. They would be the power companies. If they were interested in public welfare rather than money, they’d have given their techniques away already. If they were interested in proving the scientific establishment wrong, they’d have accepted challenges by scientific organization and demonstrated their devices in controlled situations (where they can’t cheat). The fact is, they’re just frauds and of no more interest to the power companies than snake oil salespeople are to doctors. No decent people want to see others defrauded of money, property, or health, but the free electricity people present no real threat to the power companies.

The popular notion that an ordinary person is likely to upset established science is an unfortunate product of the anti-intellectual climate of our present world. Becoming a competent scientist is generally hard work and requires dedication, time, and an enormous amount of serious thinking. Physics is hard, even for most physicists. The laws governing the universe are slowly being exposed but it has taken very smart, very hardworking people almost half a millennium to get to the current state of understanding. Each new step requires enormous effort and a detailed understanding of a good part of the physics that is already known. Still, there is a common myth that some clever and lucky individual with essentially no training or knowledge of what has been discovered before will make some monumental breakthrough. The movies are filled with such events. Unfortunately, it won’t happen. In new or immature fields or subfields, it is possible for an essentially untrained or self-trained genius to jump in and discover something important. Galileo and Newton probably fit this category in physics and Galois and Ramanujan probably fit it in mathematics. But most of physics is now so mature that broad new discoveries are rare, and accessible only to those with extremely good understandings of what is already known. A basement tinkerer hasn’t got a prayer.

Finally, real scientists don’t always walk around in white lab coats looking serious, ridiculing the less educated, and trying to figure out how to trick the government into funding yet another silly, fraudulent, or unethical research project. In fact, most scientists wear practical clothes, have considerable humor, enjoy speaking with ordinary folk about their science, and conduct that science because they love and believe in it rather than as a means to some diabolic end. These scientists use the words of science in their conversations because it is the appropriate language for their work and there is meaning in each word and each sentence. The gibberish spoken by “scientists” in movies is often offensive to scientists in the same way that immigrant groups find it offensive when people mock their native languages.

I don’t know about any patent history for the free electricity organization but everyone should be aware that not all patented items actually do what they’re supposed to. In principle, the U.S. Patent Office only awards a patent when it determines that a concept has not been patented previously, is not already known, is not obvious, and is useful. The utility requirement should eliminate items that don’t actually work. One of my readers, a patent attorney, reports that he regularly invokes the utility regulation while escorting the “inventors” of impossible devices such as “free electricity” to the door. They consider him part of the conspiracy against them, but he is doing us all a service by keeping foolishness out of the patent system. However, proving that something doesn’t work often takes time and money, so sometimes nonfunctional items get patented. Thus a patent isn’t always a guarantee of efficacy. Patented nonsense is exactly that: nonsense.

Finally, how do I know that Free Electricity is really not possible? Couldn’t I have missed something somewhere in the details? No. The impossibility of this scheme is rooted in the very groundwork of physics; at the deepest level where there is no possibility of mistake. For the counter rotation device to generate 15 kilowatts of electricity out of nothing, it would have to be a net source of energy—the device would be creating energy from nothing. That process would violate the conservation of energy, whereby energy cannot be created or destroyed but can only be transferred from one object to another or converted from one form to another. Recognizing that our universe is relativistic (it obeys the laws of special relativity), the actual conserved quantity is mass/energy, but the concept is the same: you can’t make mass/energy from nothing.

The origin of this conservation law lies in a mathematical theorem noted first by C. G. J. Jacobi and fully developed by Emmy Noether, that each symmetry in the laws of physics gives rise to a conserved quantity. The fact that a translation in space—shifting yourself from one place to another—does not change the laws of physics gives rise to a conserved quantity: momentum. The fact that a rotation—changing the direction in which you are facing—does not change the laws of physics gives rise to another conserved quantity: angular momentum. And the fact that waiting a few minutes—changing the time at which you are—does not change the laws of physics gives rise to a third conserved quantity: energy. The conservation of energy is thus intimately connected with the fact that the laws of physics are the same today as they were yesterday and as they will be tomorrow.

Scientists have been looking for over a century for any changes in the laws of physics with translations and rotations in space and with movement through time, and have never found any evidence for such changes. Thus momentum, angular momentum, and energy are strictly conserved in our universe. For the counter rotation device to create energy from nothing, all of physics would have to be thrown in the trashcan. The upset would be almost as severe as discovering that 1+1 = 3. Furthermore, a universe in which physics was time-dependent and energy was not conserved would be a dangerous place. Free electricity devices would become the weapons of the future—bombs and missiles that released energy from nothing. Moreover, as the free electricity devices produced energy from nothing, the mass/energy of the earth would increase and thus its gravitational field would also increase. Eventually, the gravity would become strong enough to cause gravitational collapse and the earth would become a black hole. Fortunately, this is all just science fiction because free electricity isn’t real.

For more information about the “free electricity” hoax, sent in by readers of this site, touch here.