Wednesday, March 15, 2006
That's a Whole Yotta Stuff. 
by Lenka Reznicek [permalink] 
I learned the names of several new metric prefixes today, a fact that gives me a pleasantly tickly feeling in my brain (either that's the sounds of neurons firing, or a few synapses frying - probably the latter). Until today, I foolishly believed atto- (10-18) and exa- (1018) defined the limits of scientific measurement. How wrong I was. There are numbers out there that would give Carl Sagan the vapors, bless his departed soul - and I'm not talking about that vaporware cop-out of a number, ∞, either.

If you're looking to describe an afwul lot of anything, you can opt for zetta- (Z), or 1021 - or yotta- (Y), 1024: the Earth's ocean, collectively measured, would yield about 1 zettaliter (ZL) of water, and the volume of the Earth is a staggering 1 yottaliter (YL).

On the other hand, there are teensy-weensy quantities that we can quantify as well: zepto- (10-21) and yocto- (10-24) prefixes are miniscule enough to approximate the mass of roughly 600 molecules of water and the weight of a proton or neutron, respectively. That's very handy, but I can't help but wonder about the origin of these prefixes - are they Greek?* Seriously, yocto?

Are scientists just making those up? Eventually, we must have to starting making stuff up, because the Greeks couldn't think of everything back in the day.

I mean, with such precision of language available, referring to "not a single iota" of something now seems so, well, nebulous. And thanks to the Internet, we all know where 10100 will lead you.

*UPDATE: According to Wikipedia, "yocto" comes from the Greek "οκτὡ, meaning eight, because it is equal to 1/10008." "Zepto," on the other hand, is derived from the French sept, or seven. Using that convention, would the next prefix for 1027 be something along the lines of "xenno-," from the Greek ennia or "nine" - or if we go the French route, "xneufo-"?

Oops. Think I fried another synapse. [Also see: Alan Wood's Unicode page for Greek Extended characters]