I've had this thought in my head for such a long time now, what would happen if you were to be shot by a bullet that was the size of an atom? Don't bring up the story with the guy who had the same thing happen to him through his head, that had lethal doses of radiation. Imagine the bullet has no radiation and is the size of an atom, what would happen theoretically?
You wouldn't even feel it.
But if you want something epic to happen, if you accelerate even a single atom close enough to the speed of light, upon impact with a person the person would explode from the sheer dispersion of kinetic energy.
It would be impossible by any conceivable technology to do that, but theoretically you could cause a hiroshima-sized explosion with a single proton traveling close enough to the speed of light.
Energy is also conserved inside a particle accelerator, and much of the energy put in is lost in plasmonic radiation, so it would take much more energy than Hiroshima to accelerate a particle to Hiroshima inducing speeds.
In other words, you'd have to blow something bigger up just to get enough energy to do such an experiment.
Also, confinement technology couldn't handle those speeds, there's no way you could contain a particle for a long enough time for it to achieve near light speed.
It's not really a case of confinement technology, it's more to do with practicality. The technology in making a LINAC a gazillion miles long is no different than making one 10 miles long- but good luck in getting funding for it.
which is what I meant by posting the link. if a beam doesn't really cause much harm, it's doubtful that a single atom will do much harm, and my guess is that higher speeds wouldn't really affect much in this case, but I'm not knowledgeable.
I don't know how fast bullets are, but you are being hit constantly by molecules with a speed of [math]\approx 300[/math] m/s. Some are even a lot faster than that.
It's the air around you. The speed of sound is just the mean velocity with which air molecules are moving.
So yes, nothing at all would happen.