With nearly 200 million cell phones in the US, and countless radio & TV stations, are there literally hundreds of millions of radio waves of distinct frequencies (each one completely unique) blasting through our mortal coils 24 / 7 /365? And aren’t there a lot of other waves also cruising through our bodies too, such as cosmic rays, gamma rays, and who-the-hell-knows rays also bombarding us? It seems hard to fathom … am I just confused because of too many waves passing through my brain?
True, although “blasting” is a bit of an exaggeration. Most of the radio waves and such generated by humans won’t travel through the earth, so you are limited to line of sight for a lot of these radio waves. In other words, if you are in California, the radio waves from the cell phones in New York are blocked by the earth. Trees, buildings, and other obstacles block a lot of stuff too. The radio waves are also spreading out as they travel, so how much radio waves hits you decreases with the square of the distance that the radio wave has to travel, which means that the waves get very tiny very quickly as they travel outward from the source.
If it’s any consolation, most of the man made stuff is safe for you. It’s not high enough in frequency to do your body damage unless you get enough radio waves to actually cook you (which is how a microwave oven works). A lot of the naturally occuring stuff isn’t quite so safe. Part way through the ultraviolet spectrum, electromagnetic radiation starts becoming “ionizing” which means that it can strip electrons off of atoms and create ions. This is why sunlight causes skin cancer, and also why “radiation” from nuclear fuel type stuff causes cell damage and cancers.
Radiation that is high enough in frequency to do damage isn’t completely bad, though. It’s thought to be one of the main mechanisms for creating cell mutations, which is what leads to evolution. If not for the “harmful” radiation, we’d still all be slugs.
Radio waves and light waves won’t penetrate the ground, but some frequencies of radiation will not only go right through your brain, but they will keep going through the entire earth and pop out the other side. Freaky, huh?
AFDB it’s the only way.
That’s not particular frequencies of radiation, that’s neutrinos (a completely different sort of particle than photons). And indeed, neutrinos will pass through you quite easily as well. Which means that they’re perfectly safe. Something can only hurt you if it interacts with you in some way, but those interactions would also tend to impair it passing through you. So the things which pass through you most easily pose the least danger.