Well, on a practical level, they're at the root of the RSA cryptography algorithm which may be keeping your email or online purchases secure

Why does the numbers being prime make a difference? Does cryptography only work on whole numbers?

It has to do with choosing really large prime numbers and multiplying them, and... someone's going to come on in about two minutes and explain it really well and make me feel stupid, so I'd rather not try. Basically, it relies on the fact that every natural number has one, and ONLY one, decomposition into prime factors -- so there's only one pair of primes that will make this very large number, but there's no polynomial-time algorithm to compute the factorization (at least, not yet). Er, and there's a whole lot of exponents and modulos and subtracting going on as well, and I don't understand the whole thing. But... yeah.

Does cryptography only work on whole numbers?

Er. I don't think this is exactly an accurate description... cryptography USES only whole numbers (at least, the stuff I'm aware of -- and that's very little!), but it works ON whatever data you've got. Which, mind you, is still encoded in bits, so I guess you could say only whole numbers. I think.

That computer science degree was quite a while ago, and I could be talking out of my ass completely.

Cryptographers will use any branch of mathematics that they need. RSA uses integers, but elliptic curve cryptography, for example, uses real numbers.

You see? You SEE? I should've left well enough alone. Wait! I think I can fix this and look less stupid.

ETA: And then, while waiting for my double-post to post, I got distracted and forgot entirely. Sigh.

You see? You SEE? I should've left well enough alone. Wait! I think I can fix this and look less stupid.

Knowing about prime numbers also helps you see why a package of brownie mix that says it makes 11 brownies is just silly. (Saw that several years ago. On a package that also said to bake the brownies in an 8x8 pan and cut them into 2-inch brownies.)

I'm vain about the silliest things. Here we have a pictorial of 11 former hunks who look crummy now. [link] The only two I ever found amazingly attractive, imho, still are. (Look, Jude and Wesley are not being saints, but they're still purty.)

On the plus side, maybe they'll lay off my boss. His lack of socialisation has not gone unnoticed by the higher-ups.

I say with love, William. When a bunch of actuaries are noting poor socialization that's hardcore.

True dat! The joke is: How can you tell an actuary likes you? He stares at your shoes.

DH and I are constantly amused by the fact that they are making him Director of Marketing. For real. DH went to a welcome meeting for the new sales force this past weekend and just sort of casually chatted up a few people. One of them introduced himself and the conversation turned to how quickly things are changing in the company. Since DH has only been there a year, he agreed. Then the sales guy said, "Yeah, did you hear they made an actuary Director of Marketing?!?"

DH just pulled a Macaulay Culkin face and said, "NO!"

When the sales guy found out who DH was, he was horrified. I think he bought DH's breakfast the next day.

I'm vain about the silliest things. Here we have a pictorial of 11 former hunks who look crummy now. [link] The only two I ever found amazingly attractive, imho, still are. (Look, Jude and Wesley are not being saints, but they're still purty.)

Ah, Vince Vaughn, you were so hot in Swingers. I forget that, sometimes, and then I see pictures and am sad.

Then again, Ricky Gervais used to be a slim pretty boy. [link] So.

Curiously, I find Large Val Kilmer more appealing than Ripped Val Kilmer. I think it's the Kiss Kiss, Bang Bang associations in my head.

And while I don't find Crowe attractive in the least, he doesn't really look much less so with the ponytail. Not sure why he's on the list. I mean, if they're comparing him to Gladiator-era Crowe, the dude already had a rep as a Huge Enormous Tool by then.