Today, microwave ovens, known as microwaves, are present in almost every home. However, many people still have concerns about them. Why is that?
In 1945, American engineer Percy Spencer noticed that food was heated by radiation from a magnetron. This discovery became the basis for the development of the first microwave oven, for which Spencer received a patent in 1946.
The first microwave ovens were released that same year. However, they did not go into mass production and were mainly used for defrosting food in military mess halls. Such devices weighed about 350 kg, stood up to 1.8 m tall, and had a power of up to 3000 W, operating on water cooling.
How does a microwave oven work?
The microwaves generated in the oven are ordinary electromagnetic radiation of ultra-high frequency (UHF) 2450 MHz, as established by international standards. This radiation does not interfere with the operation of other devices using microwaves.
Foods such as meat or fish contain dipole molecules. These molecules have a positive charge on one end and a negative charge on the other. Under the influence of an electric field, they align along the field lines. When the poles of the electric field change, the dipole molecules also change their poles.
1 MHz is one million oscillations per second. Thus, dipole molecules, like the electromagnetic field in the microwave, change their poles that many times. At a microwave frequency of 2450 MHz in a working microwave oven, the molecules infinitely change poles, rubbing against each other, which leads to heating.
Advantages of the Microwave Oven
Interestingly, radiation of a similar frequency is used in medicine to treat diseases, promoting wound healing and having anti-inflammatory effects.
food heats up quickly;
the ability to cook and defrost semi-finished products;
compact size;
ease of use.
Alleged Harm of Microwave Ovens
There is an opinion that radiation from a microwave can be harmful. For example, the journal Earthletter provides scientific data on the properties of microwaves that may cause harm, according to research conducted in 1991:
deterioration of food quality;
conversion of amino acids and other compounds into toxic substances;
reduction of nutritional value.
Some researchers claim that food cooked in a microwave oven has a low pH level. However, in modern society, it is believed that microwaves do not have a radioactive effect on a person nearby the device. Most scientists agree that the radiation generated inside the device cannot escape and affect those around it. A microwave oven can only be unsafe in the case of damage or improper use.
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