electromagnetic radiation – Why does a distant automotive key work when held to your head/physique?
Are you certain holding it to your head actually makes it higher? Your experiment could be very poorly designed as a result of you could have solely sampled situations the place the distant wasn’t working when your head wasn’t within the image. That is blatant selection bias.
Little doubt, placing the distant close to your head (or anything conductive) will considerably alter the electromagnetic radiations of the distant. However is it higher, or simply completely different? If it wasn’t working to start out, then you definitely modified one thing, then it labored, that does not imply it is higher. You’ll want to additionally attempt holding it to your head, then discover situations the place that does not work, then attempt utilizing the distant usually.
It is a widespread flaw in human reasoning at work right here. Individuals prefer to attribute success in some random or advanced course of to some ritual (on this case, placing the distant in your head) quite than merely realizing the success was as a consequence of an unrelated perturbation of the system, or just one other trial. Here is a well-recognized (at the least, to individuals of the best age) occasion of this flaw:
The NES had recreation cartridges that had been notoriously unreliable. The wrongdoer was a cheaply designed electrical contact. Little one knowledge had it that taking the cartridge out, vigorously blowing into the cartridge, and placing it again in would repair it. Every clan of youngsters in all probability had some variation on this ritual, with essential particulars, resembling pushing the cartridge up and down a pair instances, shaking the cartridge, leaving the door open, urgent the reset button a number of instances, and so forth. In actuality, eradicating and re-inserting the cartridge and rebooting the NES simply launched one other trial, and ultimately it labored. The remainder is insignificant ritual and superstition. (However do not inform any youngsters from the 80’s that — they will not imagine you!)
That is to not say it is not attainable your head does enhance the distant’s vary. Certainly, your head will likely be inductively and capacitively coupled to the antenna. Important RF currents will exist in your head, and a few of this vitality will likely be radiated, and your head will radiate in another way than the antenna within the distant.
Maybe, by advantage of your head’s elevated dimension, it makes a extra environment friendly antenna. It is also attainable, by advantage of your head’s decrease conductivity in comparison with copper, that it is a much less efficient antenna. It is also attainable your head will act as a reflector, directing extra of the radio’s vitality on the automotive. It is also attainable your head will refract the waves away from the automotive.
The purpose is we do not know. All of the analysis I’ve finished turns up anecdotal proof at greatest, by people who find themselves not RF engineers performing equally poorly designed experiments, or individuals who have talked to “an professional”. I’ve by no means seen information collected by a certified engineer with correct take a look at tools.