Pic basically unrelated, but required to post so maybe I’m in the wrong place. If there’s a better place for this lmk. Fediverse is hard to suss for locations. I looked for something like askscience but didn’t find anything and I’m not sure if that’s because it doesn’t exist or discoverability is still crap.
Basically what I want to know is what would happen if you strapped your head into something that caused medium-intensity vibration, and just left it there indefinitely (assuming you were, for the sake of this question, functionally immortal as far as age and nutrition, but not physical damage, and the vibration machine was incapable of malfunction or breakage)
I’m not talking industrial vibration, more like something we would consider safe, like an intimate toy intensity (but not a hitachi magic wand - normal people intensity), or a vibrating “weight loss plate”, or even maybe like the roughness from a long drive, assuming your head is strapped on to get the full force of it rather than your neck muscles negating some of it.
I know there’s a fluid cushion around the brain that prevents impact damage to an extent, but vibration isn’t really the same thing, so would your cells just sort of rupture over time and bleed out or is there enough padding to absorb all of it with no consequence?
Vibration has two components: frequency, and intensity.
The brain is “floating” in cerebrospinal fluid, so your question can be deconstructed into two parts: how much of that vibration would the fluid transmit, and how would brain cells react to the resultant internal vibration.
We know that high intensity vibration can cause the skull to directly hit the brain, and/or compress the fluid to a point where just the pressure can start causing brain damage. I think you can find the (mostly) safe limits in OSHA regulations.
With high enough frequency vibrations, you could induce cavitation in the fluid, making it behave like an ultrasonic cleaner. That could start popping brain cells like balloons. Don’t do that. You might search ultrasound imaging equipment frequency and intensity limits, to have an idea of what is safe.
If it’s low frequency and intensity, that “we would consider safe”… there is no reason for it to not be safe, for the brain. That doesn’t mean it would be equally safe for other structures not floating in cerebrospinal fluid, like eyes, ears, teeth, the whole skull, muscles, spine, neck blood vessels, and similar. Cells are elastic to some degree, much more than bone, so soft tissues are less likely to get damaged by “safe” vibrations.
If you strapped a tiny vibrator to a head, there shouldn’t be any damage to the brain. One kind of such “vibrator” that many people use, is headphones. You could probably check the energy output of most toy vibrators with a dB meter for a rough comparison.
Strapping a head to a road vehicle… would depend on the vehicle’s shock absorbers, but there is a reason why seats usually have some additional cushioning on them.
If you want to check on some more extreme vibration limits, look at NASA’s manned rocket launch parameters. They aren’t pleasant, yet are limited so to not cause damage. (Don’t look at fighter jet limits, those are a tradeoff between “getting shot down” vs “some brain damage”).