Coherence is not required for me to interact with the rest of the classical world, so why should it be required for me to interact with other universes?

It's required because otherwise your state vector gets entangled with the state vector of the rest of the universe, and then unitary time evolution requires that if you have a superposition alpha |psi_U> x |psi_O> + beta |psi_U'> x |psi_O'> [1] at time t = 0, and U(0,T) is the time evolution operator from time 0 to time T, then at time T the state must be alpha U(0,T) |psi_U> x |psi_O> + beta U(0,T') |psi_U'> x |psi_O'>, so the amplitude for any of the components which contain |psi_O> at time T can't depend on the amplitude for any of the components with |psi_O'> at time 0 unless U(0,T) mixes |psi_V> x |psi_O> with |psi_V> x |psi_O'> for some state of the rest of the universe V, which just amounts to postulating that the observer has an unreliable memory which depends on the rest of the universe.

[1] Here, |psi_U> and |psi_U'> are different states of the rest of the universe corresponding to projecting onto different values of some observable you have just measured; |psi_O> and |psi_O'> are different states of the observer (you) corresponding to having made (and, since they are distinct states, remembered) some observation, and x is the tensor product operator.

Well, I wasn't really considering the body per se either - if I'm still around to have to worry about the heat death of the universe, I expect I will have long since uploaded. That creates one obvious necessary condition for 'strong' (i.e., infinite subjective time) immortality (as distinguished from just the weaker requirement of indefinitely extended conscious experience given adequate physical prerequisites that medical approaches could satisfy): the ability to execute infinitely many computations.

Even a heat death of the universe scenario doesn't necessarily rule this out, because in an open (infinitely expanding, asymptotically hyperbolic) universe the temperature also asymptotically approaches absolute zero (there are other possible heat death scenarios - in an asymptotically flat universe, the temperature asymptotically approaches some non-zero value, but that does not appear to be this universe), and thus minimum the energy cost per computation also approaches zero, and if you compute sufficiently slowly in the limit, you can get infinitely many computations in infinite elapsed time for only a finite energy expenditure. This may be rather difficult to implement with the specific physics we have, though, since masses of elementary particles set a natural energy scale for differences between energies of different states, but maybe something clever could be done.

That in itself is not sufficient, though, since any finite state machine necessarily repeats after finitely many steps. This perhaps does get at your notion that the necessary evolution of consciousness over time challenges personal identity - to experience infinite subjective time, a conscious entity must transform itself in such a way that its state size increases without bound. As far as physical possibility goes, though, I think this makes it fairly clear that the question of whether 'strong' immortality is possible is isomorphic to whether a universal Turing machine is physically realizable.

What the hell is up with people always having such a strong knee-jerk reaction to argue in favor of death? No less a figure than Leonard Hayflick, who surely ought to know better, makes this exact argument. The human body is *not* an isolated system. Sure, if you mean immortality in the sense of a literal eternity then you may have a point, but as long as there's energy available to run the system on, there's nofundamental physical reason it can't continue indefinitely. I'll settle for the next trillion years and worry about it then, I think.

I don't think prosecuting a username would be a particularly effective means of enforcement, and with the hosting outside their jurisdiction it's hard to see how they could force Italian Wikipedia to reveal anyone's IP address.

Ugh. The redirect option is perfectly sensible, but putting the other thing just plain does violence to the conceptual integrity of the domain name system and I shudder at the thought that there are no people in the world who would consider one 'unprofessional' for not doing it. There are protocols that aren't HTTP, you know.

That only counts as a flaw if you've bought into the delusion that NAT constitutes a functioning network.

Do a Fourier transform of the desired waveform; the frequency-domain components are the weight of the photon state with the corresponding momentum (and polarization).

Not true; all the field observables always commute at spacelike separations, so you can't ever send information faster than light. The propagators *do* have a non-zero amplitude at spacelike separations - it exponentially decays outside the light cone - but remember that particles are indistinguishable - you can't tell the difference between emitting a photon and absorbing it somewhere slightly off the light cone, and absorbing *some other photon*. The spacelike part of the propagator just represents correlated vacuum fluctuations.

That's not a nuclear reactor, that's an RTG, and the power-to-weight ratio is a couple orders of magnitude too low to power a usable car.

On the other hand, something like the SAFE-400 would be viable, if a bit heavy. Good luck shielding one well enough that it wouldn't release fission waste products in a worst-case accident, though.

Hmmm, you must have the double secret annex to the constitution or something. The only provisions I see relating to government debt are that Congress has the power 'to borrow money on the credit of the United States' and that the newly formed federal government assumed the existing debt accrued under the Articles of Confederation.

If a federal government default is so impossible, why don't you put your money where your mouth is and start selling credit default swaps? By your theory they're free money, and it sure looks like there's an upward trend.

Option 1: They default on paying Treasury bonds as they mature, with apocalyptic economic consequences. Those bonds have long been regarded as essentially risk-free assets, and financial institutions hold them on that assumption. You know, like the senior tranches of mortgage-backed securities a few years ago, only on a scale an order of magnitude or more larger.

Option 2: They manage to lean on the Federal Reserve hard enough to get them to collude in printing money to pay the debt. Hyperinflation ensues. Possibly it doesn't even work, if the market has anticipated the possibility and driven up interest rates on long-term bonds, forcing them into issuing only short-term debt and hence having to pay rapidly rising interest rates to roll it over on maturity in a hyperinflationary environment. See Zimbabwe, Weimar Germany, 3rd century Roman Empire, etc.

With Bill Gates involved, we're sure to discover the joys of the Gamma Screen of Death soon.

... or maybe: "Your Microsoft Nuclear Reactor is experiencing a prompt criticality incident. Please remove all the fuel rods, reinstall them, and restart the reactor."

I'm not implying that you are a fascist or totalitarian thug. I'm directly accusing you of it based on immediately obvious observations. Your willingness to do violence to random third parties for consuming substances you dislike in private is clearest, but the real clincher is the law-worshipping mentality evident in your original post: you regard law as defining ethics, and identify yourself with its enforcers. It's the classic authoritarian submission trait identified by Theodor Adorno.

This is, of course, a complementary to the authoritarian aggression trait: you assuage your psychological insecurities by identifying with established power, and express your sadistic tendencies vicariously through its violent enforcement, which is why you find criticism of that structure so threatening. Really, people like you are the slime of humanity; merely pathetic when encountered singly in a context like this, but lethally dangerous in sufficient numbers.

Oh, and for the record: I'm more of an LSD sort of girl.

Well, I see the laces on someone's jack-boots are just a bit too tight...

You don't need to keep the commands to the lights secret; you just need to authenticate them. Each light having a copy of a single signing key and digital signatures on the messages will suffice.