> I wonder to what extent we’ll manage to get science fiction out about these things before we start seeing them in practice.

Its not an exact match, but reminds me quite a lot of Snow Crash

That a good point, though the answer is rarely. Theres something like 1 molecule / cm3 (though places can be less and more)

Every now and then one of those atoms will get close enough and the tuning fork will knock it away making 'noise'. Presumably if one hits at the right time itll add energy also.

Both events are going to be fairly rare.

I mean, photons make up everything we can see, inside and out right?