How do microwave ovens work and do they trigger most cancers? – Attention-grabbing approach
Microwaves are a very useful cooking device. They are compact, tiny, but incredibly versatile machines – how do they work?
There is an incredible amount of science and technology behind microwaves, but everything can be broken down into easy-to-understand and digestible pieces.
Microwave ovens work primarily by generating microwave radiation that is passed through the food and cooked there. Microwaves are not specific to microwave ovens, but a form of electromagnetic waves with a wavelength in the frequency range between 300 MHz and 300 GHz (a wavelength of approx. 1 m and 1 mm). M.Microwave ovens generally use a frequency of 2450 MHz (a wavelength of 12.24 cm).
Compared to other types of radiation, microwaves fall between radio waves, which tend to be longer, and infrared waves, which are shorter.
What makes microwaves so specialized for cooking is the way they interact with water molecules.
The science behind microwaves
In microwave ovens, the microwaves are created using a device called a magnetron. Magnetrons are essentially high-voltage motors that emit energy in the form of microwaves rather than mechanical work.
In the microwave oven, a transformer feeds electricity from the socket. 120V in the US or 110V around Europe 4000 volts. This increased voltage is needed to power the magnetron, which causes a filament in the core of the device to heat up. As this filament heats up, electrons are released. The microwave oven makes these electrons work.
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A circular magnet is placed near the heated filament. Usually, the electrons released from the filament are attracted to the anode, but due to the positioning of the magnet, the electrons return to the filament itself. This electron loop actually creates microwaves.
All of this may have sounded a bit complex, and it can be if explained without diagrams. Check out the video below for a deeper look at how magnetrons and ultimately microwaves work.
Can you safely stand next to a microwave?
A popular myth about microwaves is that they can cause cancer. This may be due to the use of the word “radiation” in describing how it works, as well as a fear that this microwave radiation may leak out of the microwave. Radiation, in this case, refers to energy emitted from a source, not radioactivity.
However, microwaves do not contain enough energy to chemically change substances through ionization – they are an example of non-ionizing radiation. Other types of electromagnetic waves, such as ultraviolet and X-rays, have more energy per photon and can therefore cause cancer.
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Microwaves can of course cause heating and burns, but all microwave ovens have a metal grille on the door of the appliance to keep the microwaves from leaking. These metal grids are big enough so you can see your food cooking, but the holes aren’t big enough for the microwaves to slide through. Microwave ovens also have built-in safety devices that prevent the oven from operating with the door open.
So at the end of the day you won’t get cancer if you stand too close to a microwave because the rays don’t ionize and you won’t be cooked either.
We went through the basic research, but we still haven’t explained why exactly microwaves work so well for heating food quickly.
How microwaves heat water molecules
The microwaves used in a microwave oven are sent out via a type of antenna that directs them into the cooking area of the device. The waves are contained inside the device thanks to the massive metal walls (and the mesh door). These microwaves are then absorbed by the water molecules in the food. The energy from the microwaves causes the water molecules to vibrate quickly, which heats the food.
Since water molecules easily absorb microwaves, causing the molecules to vibrate quickly, this essentially becomes a mechanism to convert microwave energy into thermal energy. Just as a cam and roller are a mechanical device for converting rotational energy into linear motion, the interactions of microwaves and water molecules are also a way of converting microwave energy into thermal energy.
But why are only the water molecules vibrating? Water molecules are polar, meaning they have a positively charged side and a negatively charged side. Microwaves have a positive and a negative vertex, just like any wave. As the microwaves move inside the microwave oven, the water molecules try to align their poles with those of the microwave. Because microwaves move quickly inside the device, the water molecules quickly try to align with the movement of the waves.
How fast does it go? The positive and negative fields of the microwaves move about 2.5 billion times per second. When you combine this effect with the reaction of the water molecule, you can see how microwaves cook food so quickly and effectively.
Why do microwaves cook unevenly?
The last question we need to answer is why there are often dead spots inside microwave ovens. For example, why is the center of your meal often much colder than the edges?
This is because some of the microwaves cancel each other out. Often these cancellation locations are localized, which means that some areas of the microwave oven are not receiving “heat”.
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When the top of one wave hits the valley of another wave, the result is essentially an extinguished wave. For this reason, most microwaves use a rotating bowl to ensure even cooking.
This is how microwave ovens work. These are devices that use magnets to generate electromagnetic radiation of a specific wavelength, which is aimed at water molecules in food, causing them to vibrate and heat up quickly. The next time you cook something in the microwave, don’t see it that way.