Where Does Solar Energy Come From

When it comes to fields and radiation, many people think of radioactivity and other invisible threats. But radiation is everywhere around us and does not always have to do with radioactivity. Some radiation is even indispensable for life on earth, such as sunlight.

Natural forms of radiation are cosmic radiation and UV radiation from the sun. For special applications, radiation is artificially generated, such as in tanning beds, microwaves and mobile telephones. But radiation and fields also arise as a by-product. That happens when you use electrical devices, and during the transport of electricity through high-voltage cables. Whether radiation and electromagnetic fields are dangerous depends on the species, the strength and how long someone has been in contact with it.

Radiation or field?

Electromagnetic fields are present wherever there are electrical charges. Such a field consists of electric and magnetic waves that move together. An electric field is created by the presence of electric charge. A magnetic field is created when the electrical charge moves (current). The strength of an electromagnetic field decreases the farther you are from the source.

Collective name

The term electromagnetic field is a collective name that includes various types of fields and radiation. Light and warmth are examples that everyone can observe. But there are also species that you cannot observe. Think of the microwaves of the microwave, the radio waves of radio, television and mobile telephone traffic, and electromagnetic fields of electrical appliances.

We usually speak of ‘fields’ when it comes to electromagnetic waves with a low frequency (measured in Hertz, or Hz). Fields have little energy. For high-frequency electromagnetic waves, ‘radiation’ is usually used, and a lot of energy is involved.

Fields: ELF and RF

When electromagnetic waves travel at a low frequency, we usually speak of electromagnetic fields. These are fields from 50 Hz to 300 GHz (GHz stands for gigahertz, or 1 billion Hz). This group can again be subdivided into (among other things) extremely low-frequency (ELF) fields and radio-frequency (RF) fields.

Current: extremely low-frequency

The current in the socket and in high voltage pylons has a frequency of 50 Hz. That is why the electromagnetic fields that arise are called Extremely Low-Frequency fields. More about this on  ELF fields through electricity .

Wireless communication: radio frequency

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Mobile phones, wireless internet and radio and TV channels use fields with a frequency of 100,000 Hz to 300 GHz. These are so-called radio frequency (RF) fields. More about this on  RF fields through wireless communication.

Radiation: from UV to particles

If the electromagnetic waves have a high frequency (more than 300 GHz), we usually call that electromagnetic radiation, in short: radiation. There are also different types of these.

UV radiation

About five percent of the light emitted by the sun consists of ultraviolet (UV) radiation. Protecting your skin and eyes from UV rays is important because excessive exposure increases the risk of skin cancer and cataracts. UV rays can damage cells and tissues. Lubricating well and avoiding bright summer sun is therefore wise, especially for children because they are at increased risk. To protect your skin against excessive sunlight, the KWF recommends: lubricating, clothing and keeping away . The eye fund explains why you need good sunglassesto protect your eyes from UV rays.

Ionising radiation

Ionizing radiation is very powerful and can turn atoms into ions. In the irradiated tissue, particles are ejected from an atom, as a result of which the atom changes into an electrically charged particle (an ion). If that happens in living tissue cells, the owner of the tissue can get sick. Ionizing radiation can, for example, cause cancer because DNA can damage it.

Well-known examples of ionizing radiation are x-ray radiation and the electromagnetic radiation that is released from radioactive substances (so-called gamma radiation). The health risk of a single low dose of ionizing electromagnetic radiation that lasts a short time (such as during an X-ray or CT scan) is very small.

Radiation from radioactive substances can contain another type of ionizing radiation in addition to gamma radiation: particle radiation. In substances that are radioactive, the atoms change composition. The atomic particles that are released during such a change (electrons, neutrons or protons) form the particle radiation. The radiation from radioactive substances is often called ‘radioactive radiation’. That is just not true, because the radiation itself is not radioactive. The type of ionizing radiation that is released depends on the radioactive substance.