Question: Theoretically, could a smaller version of radio telescopes be built to examine human brain waves in an appropriately shielded lab? If so, shouldn’t this allow us to see EM patterns in the brain the same way you do in space? Thanks. – John
Answer: Brain (alpha) waves have a frequency of about 7.5 to 12.5 Hz. This is an extremely low frequency, with a corresponding wavelength that is tens of thousands of kilometers. The wavelength is important as in order for a radio telescope antenna to be able to receive a particular wavelength of electromagnetic radiation is must be at least as large in size as about one-quarter of the longest wavelength that you want to receive. Fortunately, it turns out that one can build a receiver to detect frequencies this low, as long as an antenna with the required length can be made (possibly using a “loop” antenna). So, what you suggest seems feasible, though I am not aware of it having ever been tried in practice.