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Comment Re:Neutron Activation Analysis (Score 3, Informative) 210

Fusors are a standard neutron source, and they're fairly straightforward to build.

The idea that you could throw hydrogen ions at each other with enough energy to fuse is fairly obvious. It turns out that the obvious ways of doing so are orders of magnitude short of generating net power, but they do generate neutrons.

Comment Re:Who's law do you want to use? (Score 1) 243

This "harmoization" of US law with other countries is getting really old. We need to decide what we stand for and do it. Others can do as they wish. Why don't we just dump our whole government and put the states under some other one? Since we think adopting all their rules is a good idea... That is the stupidest reason I've ever seen for changing a law, and it gets used more often than a stupid idea should come up.

Eliminating arbitrary differences in regulation is stupid?

Comment Re:I'll be first to say WTF (Score 1) 700

I don't know, you seem to think factorization is in np-complete while rsa think it is in np-hard. I'm going to go with rsa.

I think no such thing, and neither do they.

Remember how my first response in this thread was that you had your definitions backwards? I'm saying factoring is NP-easy. Nobody who actually knows what they're talking about thinks its NP-hard.

A problem doesn't need to be hard to reduce it to SAT.

Comment Re:I'll be first to say WTF (Score 1) 700

I had it exactly right. They cannot use a 3-sat solver on "does N have a nontrivial factor smaller than m?" because the latter is not in np-complete.

You can use a 3-sat solver on any problem in NP. It doesn't have to be NP complete.

An instance of "does N have a nontrivial factor smaller than m?" *trivially* turns into a circuit. The circuit is just a bunch of multipliers and an OR gate!

Next up, a circuit trivially turns into a boolean formula. I hope I don't need to spell out the equivalence.

Third, they take the resulting formula and plug it into the reduction from SAT to 3-SAT.

Fourth they plug said formula into their solver.

Nor can anyone with an np-complete solver trivially do that.

Take above steps, but replace reductions depending on exactly which problem the solver solves.

And yes, of course a legitimate proof implies that every problem in P is NP complete. That's obvious.

That's great. The fact you can use a solver for any problem in NP-complete to solve any problem in NP is even more obvious. It's why NP collapses to P if NP-complete is in P!

But it doesn't screw RSA because RSA security is based on the fact that an efficient algorithm for factoring integers is unknown, not that such doesn't exist

Security by obscurity, eh? Luckily, it's not a problem for a constructive proof that P=NP, since the reductions are all known.

Comment Re:I'll be first to say WTF (Score 1) 700

Integer factorization is not (yet) np-complete, so technically no one can do what you are asking

You've got it backwards. A problem being NP-complete means you can reduce any problem in NP to it.

The problem "does N have a nontrivial factor smaller than m?" is in NP. A solver for that can easily be used to factor integers.

even if they have a legitimate proof of p=np.

Technically speaking, a legitimate proof that P=NP implies that every problem in P is NP complete.

What we're talking about is not proofs but rather unproven algorithms which seem to scale because they aren't run on hard inputs.

Comment Re:I'll be first to say WTF (Score 1) 700

The proof is that there is no proof.

This is one of those extraordinary-claims-require-extraordinary-evidence cases. "I tried random inputs" is not good enough. To take it seriously, those random inputs should correspond to hard problems -- for example, use this supposed 3-SAT solver on reductions from integer factoring to factor an RSA number.

Comment Re:Warp drive? (Score 1) 633

Why would it violate causality? If the space is bent and you transverse a shorter distance, then all causality rules still apply.

The causality violations aren't local. Everything is causal to you in your warp bubble but in the reference frame of a sufficiently fast moving observer you still arrive before you leave.

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