fascinating.
Size doesn’t matter.
Slan,
D. 
Wow! That is neat!
And to think I almost didn’t look, because it was about size and Amar found it fascinating and I thought that was worrisome!
there there now!
Wow… is my mind racing! 
Dangit. I clicked just so I could see a representation of Planck length relative to an electron, and I guess it just can’t be done with pixels.
I had been thinking about how to convey to someone the difference in size between a dust particle and a vapor molecule. Some people mistakenly think a dust mask will protect them against hazardous vapors.
So I found the difference on these charts between the diameter of a water molecule and a talcum powder grain and then I went to measurements of bigger things and, roughly speaking, a water molecule (the vapor) is to a grain of talcum powder (the dust) as a large ant is to Mount Everest. So now I could say that a dust mask might keep out something like Mount Everest but things the size of ants, like toxic vapor molecules, could easily get through those holes.
What an odd coincidence that you should post these charts just as I was thinking about this.
I may be way off base here, but aren’t the activated carbon dust masks supposed to work on vapours by adsorption, as oppossed to absorption?
djm
That’s right, Cynth! A dust mask or surgical mask will not protect against vapors!
They won’t even protect against really itty stuff! You need a properly fitted respirator for some viruses.
For toxic gases, you need a mask with an air tank.
Sigh. It is soooo nice not to work in any of those places anymore! Soooo very nice! Yes it is!
That’s easy for a six footer to say. 
( 
)
Hey, if I measured myself in Planck lengths I’d sound really big. 
Circumference? 
Hey, Moderator, the bigger boys are bullying me again. 
The pips are squeekin’ again… 
They were always nothin’ without Gladys, anyway.
Bit early to say goodknight isn’t it?
Yes, that’s quite right. If, as my husband pointed out to me, the holes were small enough to prevent toxic vapors from going through, then they would probably prevent oxygen and carbon dioxide from going in and out as well. So, for vapors, chemical means or some other means have to be used, and I think the masks are usually called respirators—I don’t know the in’s and out’s of this part of it because I always worked in a hood. I just needed to make sure people didn’t use the dust masks in the wrong situation.
I used to have to make sure that people who hadn’t had any chemistry, and thus didn’t know exactly what a vapor was, knew that a dust mask would not protect them at all from toxic vapors. I never felt they quite knew what I meant, although they followed my instructions. So I just started thinking that if I could have put it in terms that they could visualize, then they would have had a clearer picture of what I meant.
I like the visual comparison method. It is almost impossible to grasp what a measurement really means when it is so large or small relative to the objects we are accustomed to dealing with.
On a tenuously related note, supplied-air respirators (like an SCBA mask but with a big hose and fan out in the ‘clean’ air) can be fun. At the boatyard I once worked at, the usual joke was to break wind near the inlet of the supply-unit. One fellow thought this was a great joke, but ended up being chased around the shop by his enraged co-worker with a chopper-gun, showering liquid polyester and chopped glass fibres everywhere.
Shortly thereafter, the boss changed us over to full SCBA, with tanks that nobody could mess with.