Questions tagged [microwaves]

Microwaves, broadly defined, are electromagnetic radiation with wavelengths ranging from one meter to one millimeter; or with frequencies between 300 MHz (100 cm) and 300 GHz (0.1 cm). This range includes both UHF and EHF (millimeter waves) and the entire SHF band (3 to 30 GHz, or 10 to 1 cm).

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13
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3answers
29k views

Why do metal objects in microwaves spark?

I heard that electrons accumulate at points on metals, and this clearly explains the arcing phenomenon, but how does a microwave make an electron imbalance on the fork?
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3answers
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How does the grid on the microwave oven window prevent microwave radiation from coming out?

If I look through the microwave window I can see through, which means visible radiation can get out. We know also that there is a mesh on the microwave window which prevents microwave from coming out. ...
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2answers
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How can wifi penetrate through walls when visible light can't?

I did search the question on Physics S.E considering it would be previously asked. I found this How come Wifi signals can go through walls, and bodies, by kitchen-microwaves only penetrate a few ...
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1answer
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Does a domestic microwave work by emitting an electromagnetic wave at the same frequency as a OH bond in water?

I was told once that microwaves work by exciting water molecules in food. Also that this worked because the frequency in the microwave was the same as that in the bond between Oxygen and Hydrogen in ...
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6answers
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Could cell-phone radiation cause cancer?

It is very crucial that I ask whether it could and not whether it does. I do not mean to be the least controversial. To my surprise, having read "Physics for Future Presidents" by Richard Muller last ...
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4answers
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Why do we use microwaves in microwave oven?

We know that any object above absolute zero emits electromagnetic radiation. So hotter the object shorter the wavelengths. In the electromagnetic radiation spectrum radio waves has the longest then ...
13
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1answer
5k views

Can microwaves affect WiFi?

I listen to the radio via my iPad with wifi. When I switch the microwave oven on, the radio cuts out. When the microwave oven is finished, the radio comes back on. (This is 100% reproducible!) So - ...
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2answers
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Why do microwave ovens use radiation with such long wavelength?

According to Wikipedia: Consumer ovens usually use 2.45 gigahertz (GHz)—a wavelength of 12.2 centimetres (4.80 in). Typically, I put the dish inside the oven in its center. I suspect most people ...
2
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0answers
200 views

What is the lowest energy atomic transition ever detected and identified?

In this concise and insightful answer it was pointed out that atoms can have an extremely large (possibly infinite) number of bound excited states. The Rydberg formula represents a simple model for ...
72
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13answers
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If visible light has more energy than microwaves, why isn't visible light dangerous?

Light waves are a type of electromagnetic wave and they fall between 400-700 nm long. Microwaves are less energetic but seem to be more dangerous than visible light. Is visible light dangerous at all ...
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What makes cheese so effective at absorbing microwaves?

Whenever I put a meal in the microwave which contains cheese, why does the cheese get hot before the rest of the meal is heated through?
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4answers
12k views

Why don't we use infrared light to heat food?

Why don't we use infrared (IR) or even the far IR just to heat food in a microwave oven instead of, of course, the conventional 2.45 GHz microwaves? Don't people call IR heat waves?
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4answers
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Is it possible to shield a camera so as to record from the inside of a running microwave oven?

Would it be possible to create shielding for a camera, allowing it record food being cooked from the vantage point of the inside of a consumer microwave oven without the camera being damaged? ...
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5answers
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How come Wifi signals can go through walls, and bodies, but kitchen-microwaves only penetrate a few centimeters through absorbing surfaces?

The only difference that I know of between kitchen microwaves and WiFi signals is how much power is pumped through them. Why is it that WiFi signals, being 1000 times weaker can travel so much ...
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2answers
6k views

Do Microwave oven heating times grow linearly with Wattage? Calculating optimal heating time

So this is a completely random and trivial question that was prompted by looking at my microwave oven and the back of a TV dinner and my google searching failed to produce a meaningful answer so ...
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2answers
759 views

Why does plastic wrap grow, then shrink, then grow again when microwaved?

The other night I was reheating a bowl of leftovers in the microwave. There was a fair amount of liquid in the bowl, so I covered the bowl with plastic wrap when I put it in the microwave. When I put ...
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2answers
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How can we detect cosmic background radiation?

From what I understand, CMB is the left over radiation from the Big Bang. As all matter, including the Earth, was made during the Big Bang and then as the universe expanded that matter/energy got ...
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1answer
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What properties make a good barrier for microwave (oven) radiation?

Suppose I have plenty of food I want to heat (which will provide load) in the microwave, and one item I don't want to heat. What properties would make a material a a good shield, to reduce or prevent ...
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2answers
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What would a graph of temperature increase of a cup of water in a microwave look like?

My lunch had been in the microwave for a minute or so, and I was wondering if I took it out 10 seconds early, would the amount of temperature it increased in that 10 seconds be more significant, less ...
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3answers
215 views

Can radio waves be harmful to us?

I was studying about Microwaves and their action on water molecules in heating up the food. This all is probably due to Microwaves have wavelength such that it can be absorbed by water molecules (am i ...