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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).

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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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 and why not?
suse
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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?
Robert Frost
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Why is Microwaved mac & cheese burnt where they touch?

After reheating cold about 1.5 oz. of Annie's Mac & Cheese shells for 15 seconds on high power in the microwave, the mac & cheese was burnt black only at certain points where the pasta is touching each other. Does anyone have an idea of what might…
Zooky
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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?
ObsessionWithElectricity
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Why does canola oil heat up in the microwave?

Introduction: I read on Wikipedia's list of common misconceptions that microwaves work not by emitting the resonant frequency of water, but as a result of dielectric heating. As I understand it, this process heats a substance by emitting a…
i like math
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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, but kitchen-microwaves only penetrate a few centimeters through absorbing surfaces? But in this…
Shashaank
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How to imagine WiFi signal propagation?

When thinking about how the WiFi signal propagates through a household, can I use the following thought experiment? Assume absolute darkness. Place a strong lightbulb where the WiFi access point is. The illumination that reaches various places in…
vektor
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Stood in front of microwave with the door open

I was cooking something in the microwave and opened the door early to check on it and the microwave didn't stop. I didn't realize this for a few seconds and when I did I shut the microwave off but I'm concerned what I could have been exposed to for…
Mr.Smithyyy
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How do microwaves heat moisture-free items?

Today I learnt that microwaves heat food by blasting electromagnetic waves through the water molecules found in the food. Does that mean food with 0% moisture (if such a thing exists - dried spices?) will never receive heat from a microwave oven?…
Daniel Wilson
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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. My question is how does this work? how come…
Revo
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Why does chocolate burn if you microwave it with milk?

Chocolate Science! I melt 3 spoons of dark chocolate in microwave oven in low. It melts in 3 minutes and it's just mildly warm. I add half a spoon of milk which makes it a bit cold again. So I microwave it again and in 10 seconds it BOILS!! In 20…
Anonymous
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Why are there different explanations of microwave oven heating, eg dipole alignment vs absorption? Is it quantum vs non-quantum?

There seems to be different explanations of how microwave ovens work. Here are the two basic forms of explanation I've heard: A. As microwaves pass through, the molecule dipoles try to align with the electric field, causing rotation and increased…
cjphysics
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In a microwave oven, why do smaller portions heat up faster?

Sorry for brevity, but what is the exact physics explanation of why smaller quantities placed inside a microwave oven heat up faster than when you place a larger quantity of a similar material inside?
yigal
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When a microwave oven stops, why are unpopped kernels very hot and popped kernels not hot?

A commonplace empirical observation is that when a microwave oven stops, unpopped kernels are very hot (it's physically painful to touch them) and popped kernels are not. Is there an elementary (or not) exposition of the physics involved?
Michael Hardy
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What happens in an empty microwave oven?

What it we don't put any food in a microwave oven? I.e. nothing to absorb the microwaves? Would the standing microwave modes in the 3D cavity be reinforced? Would there be too much energy in the microwave?
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