There is circumstantial evidence that he isn't Satoshi, eg, he doesn't sound like Satoshi sounded, he doesn't act in ways congruent with Satoshi's actions, he doesn't seem to share goals with Satoshi's actions, he doesn't seem to have knowledge Satoshi had, etc.
On the other hand, it's absolutely possible that Wright is Satoshi, and is simply engaging in an elaborate hoax in which Satoshi does a great job of pretending to be someone else who is doing a bad job of pretending to be Satoshi. It could be!
Bottom line though: The real Satoshi could trivially prove he was Satoshi if he wanted to; Wright has not. Either 1) he's not Satoshi, or 2) he doesn't want to prove that he is Satoshi. Given that he spoke to the BBC in an apparent attempt to prove he is Satoshi, we can provisionally rule out option 2, leaving option 1:
Or he was forced to publicly admit he is Satoshi, maybe by his lawyers, but he did it in such a ridiculous manner so that nobody will actually believe him, while fulfilling his obligation to admit.
It's a pretty extraordinary claim which would require similarly extraordinary evidence.
From what I've read so far the "evidence" does not barely reach "ordinary" and seems to be straight up bullshit[0][1]. Considering the last round of "Craig Wright is satoshi" ~6 months ago was similarly bullshit[2] at this point there's a pattern of Wright being a bullshit artist.
Either way, popcorn time, fun to watch from the sidelines.
Is there any actual evidence that you aren't Satoshi?
You can't prove a negative. There's absolutely no published evidence to support the claim that he is Satoshi, and there's no reason to believe that he is.
More precisely, proving a negative requires quantifying over the entire underlying model and applying the law of excluded middle or double negation elimination. Proofs of a positive are generally constructive, and valid in intuitionistic logic which rejects the law of excluded middle as an axiom.
So you can't prove a negative if:
* It is infeasible to quantify over the entire underlying model
* You're working within a logic that doesn't admit it as an axiom, for practical reasons.
It's easy for me to argue that there are no pink ducks on my desk. It's very difficult to argue that there are no pink ducks.
People usually use "pink duck" as "example of thing that is unlikely to exist". If you choose "proposition guaranteeing that the thing doesn't exist", I think you get this argument:
Claim: There are no non-existent objects.
Proof. Let x be a non-existent object. x is a witness for its own proof, so x exists. Contradiction.
That one works in a couple logics I looked up. People boldly claiming that "For any predicate P, forall x. ~P(x) is unprovable" would have to reconcile this example. Also, the empty model satisfies that.
Of course, he may have literally meant "You can't prove a negative", as in "lumberjack on Hacker News is unable to produce a proof of any formula in the format given above". That depends on how eagerly you evaluate "You".
That's an easy one, just have to restate it differently and it works: (not dead) == alive. So, is there any evidence that you are alive? Well, yes, there is.
Unfortunately, proving that you are "not (not Satoshi)", doesn't prove that you are. The negative space is not one to one, but one to many.
Um. Yes it does. If you prove that you are not (not Satoshi), then you prove that you're Satoshi. There is this widespread myth that "you can't prove a negative" when, in fact, you can.
You might have been meaning to point out that the characters of evidence needed in either case are somewhat different: the problem with proving some negatives via an argument from silence is that an absence of evidence is expected. You see, it's an absence of expected evidence that's evidence of absence! If, given something were true, we wouldn't expect to have evidence of it, then such "arguments from silence" (we lack evidence, therefore it's not true) do not work.
So when I want to prove that someone is not a giraffe, I can reasonably expect that if they were, they would have a long neck, walk on four long legs, probably stand taller than a given human -- if I see no evidence that they have any of these, we have an absence of expected evidence. This functions as evidence of the absence of their giraffe-ness.
But when I want to prove that someone is not immortal, say, there is no expected evidence of immortality for me to hang my hopes on. I mean, I might hope that they'd been born long enough in the past that they'd have documentation of their existence lasting out hundreds of years, but I'd have to introduce more assumptions to expect this. Or I might hope that they'd been subjected to lethal force sometime during their lifespan and lived through it, but in the posh, cushy developed world there's not necessarily any reason to expect that the typical 30-year-old has suffered a grievous injury, so I'd have to introduce added assumptions about their rough past before I could expect this. Still, proof would still be possible in such a circumstance -- just ask them to kindly survive stepping in front of a train or so -- and the negative could be proved. It's just that it can't be proved by an argument from silence.
The usual way to make this semi-rigorous is to use the definition of conditional probability, where the event "A given B" is written "A | B" and its probability is defined as Pr(A | B) = Pr(both A and B) / Pr(B). Then we have some claim C with some new evidence N and some old evidence O; we can prove that three numbers that need to be known:
P = Pr(C | O)
the prior probability of C before adding evidence N;
Q = Pr(N | O and C)
the likelihood that C would generate this evidence N, given the old evidence,
R = Pr(N | O and not-C)
the likelihood that not-C would generate this evidence, given the same.
The expression for the probability that we want to know is then:
Q * P
Pr(C | N and O) = --------------------
Q * P + R * (1 - P)
An argument from silence is just an argument where the new evidence N to be incorporated is the lack of some observation, for example the lack of observed dying after being shot by a gun, or the lack of observing a long neck on a person claimed to be a giraffe.
We can then see that arguments from silence are still supportive (Pr(...) > P) whenever Q > R, but may not raise P to the level where we'd really bet on it. In particular if P is very unlikely (e.g. immortality would have a P of one in 10 billion or worse, given what we've seen about the world), then with Q=1 (e.g. not dying when shot, given immortal), you're still looking for R to be commensurately tiny (e.g. the shot must have survival odds 10 billion to 1 against) to raise the argument from silence to a decisive position. Any weaker sort of silence does not confirm it enough to raise it to the level of plausibility, although of course you can rinse and repeat with N now incorporated into O (so we can talk about someone who has been shot, poisoned, and hanged many times on many different occasions and each of them might have a 1/100 survival rate; still if we have her surviving 5 such things which are individually bad evidence, we may get a non-negligible probability that all together they are good evidence and either she's conspiring with her killers or else maybe she is, in fact, immortal.)
That exactly the opposite. Can you prove in absolute terms that aliens or bigfoot don't exist (with current technology and information)? No. If you had bigfoot chained up could you prove he does exist? Yes.
(a) It means he's got a few hundred million dollars stashed away in BitCoin.
(b) He can then claim priority as benevolent dictator for life, with a reasonably good chance that the community will follow him. For example, he could probably fork BitCoin to have more frequent transactions and larger block sizes, and his fork would hit a critical mass of users to the point where the BitCoin Core group would have to accept those changes or else risk a blockchain split which could kill the currency altogether.