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Comment by dekhn | Hacker News Reader

We use EM radiation for illnesses and doctors apply them. It's one of the most important diagnostic and treatment options we have. I think what you're referring to is invalid therapies ("woo" or snake oil or just plain ignorance/greed) but it's hard to distinguish those from legitimate therapies at times.

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> We use EM radiation for illnesses and doctors apply them.

Do you have examples of usage as a treatment? I can only think of rTMS (whose effectiveness is contentious).

The most boring example is x-rays. Slightly less boring are the radiation therapies for cancer.

What is maybe the most applicable that is widely accepted is electric therapy for people recovering from ACL surgeries.

Gamma knife? Basically the entire field of radiotherapy? TMS is magnetic, not EM (the coil generates a magnetic field, which induces localized currents in the body being treated)

>TMS is magnetic, not EM (the coil generates a magnetic field, which induces localized currents in the body

ME? the coil generates an M which induces localized E in the body as shown by localized currents? (which produce some more M, but only just enough)

I can't parse what you are saying, but there's a difference between EM radiation and a magnetic field (and the resulting locally induced currents). Think in terms of an MRI machine: it puts you in a giant magnet (causing the various nuclear spins to align with the field) and then sends a bunch of EM radiation (radiofrequency). The former is a magnetic field, not EM radiation.

it's all E x B, just different functions for E and B

OP is making a distinction between "EM Radiation" (i.e. "light") and "Quasistatic fields".

This is warranted because they are pretty different - light has a frequency distribution, diffracts, etc, and can be focused to propagate energy over distances large compared to its source, whereas quasistatic fields (by definition) have no frequency distribution, and die as 1/r^2 or faster

Jaundice in babies is treated with EM radiation in the 420–470 nm range.

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