That's a reasonable analogy. Both cases are driven by external factors (mathematics for IPv4, atmospheric chemistry for gas-powered cars), and the authorities are doing a fairly poor job of solving the collective action problem.

Everybody *wants* to stuff a trillion numbers into 32 bits, and stuff infinite carbon into the air, but reality doesn't care what we want.

Suppose you have a PC on an internal IPv4 network, connected to an IPv6 edge router. You type "ipv6.google.com" into your browser. What address should it connect to?

Yes, that's the real news here. Chrome has been butchering URLs for several years, and the problem is finally solved.

Having a choice between "real URLs" and "kindergarten mode" is a massive improvement.

AT&T has more IPv6 users than any other ISP in the world:
http://www.worldipv6launch.org/measurements/

Granted, it's all based on 6rd, but you can't say they're not trying.

on my work network, we've got an integrated PKI that makes it easy for people to exchange their public keys. If I'm sending someone a password or other sensitive information, I'll encrypt it against their keys there. If I'm just talking to someone (ie: not doing anything sensitive), encryption is off, signing is on. If I'm sending from my personal email, the only person I encrypt to is my work email.

I think the big reason that email encryption in general hasn't taken off is that it's a huge pain to exchange keys. Some keyserver attempts have been made, but frankly there's not been enough adoption in any circle I've seen to really call it a success. The only time this stuff seems to really work well is when there's a corporate directory and a mandate from management that says "you will get a pki certificate, and you will publish it on the global address list".

So the paper talks about SBPR (sorting by prefix reversals) and MIN-SBPR. The question is not "here, sort this stack of pancakes", it's "determine what the minimal number of flips is to sort an arbitrary stack of pancakes of size n".

If I'm following this, then sorting the stack itself is relatively easy (as you said, n^2). Figuring out the optimal sorting is apparently what's hard.

"size of the problem to some power" is the definition of polynomial time. Polynomial time problems are generally considered "easy" -- for example, your typical sorting algorithm is between n*log(n) and n^2. These grow slowly enough that general polynomial algorithms, even with relatively high exponents (like n^3 and n^4) are doable for reasonably large input sets.

The time it takes to solve an NP-hard problem is more in line with "a constant raised to the power the size of the problem". So doubling the size of the input squares the computation involved. So like ... no known general solution to SAT is better than 2^n.

So what that means is going from input size = 10 to input size = 20 would require a million times more power, and input size = 20 to input size = 21 would require twice the power that it would take to do input size = 20. This is WAY worse than n^x (where x is a constant).

I'll rent you a solar system for only $1,000/day, but you'll need to find your own transportation.

Weld the cables? Are you insane? Those things must cost thousands of dollars.

Brilliant, then you need to deal with half hours every time you convert to/from UTC.

I think App Engine is the only one in the list that currently supports IPv6 hosting:

http://www.google.com/support/a/bin/answer.py?hl=en&answer=177065

If all you need is a backup set of optics, just make the pilots wear an eyepatch.

You forgot "mother". Incidentally, I'm telling her you said a bad word.

So, when everything's on IPv6, and you want to play an IPv4-only game, you'll first have to establish an IPv4 VPN between the players? I suppose that sounds feasible, but someone will have to write the software to make it easy.

You do realize that the ISPs would be the ones doing the prioritizing, right?