Alice in Wonderland

We were watching The Incredible Human Journey last night (delayed by the wrong kind of snow from Sunday or something like that). At one point the discussion turned to the first encounters between modern humans and the incumbent European humans - the Neanderthals. The learned professor who Double Doctor Alice was talking to, suggested that the meeting would have been an profoundly interesting moment and this got me wondering if it will ever be possible to re-construct the exact moment that it occurred. There is a device in Stephen Fry's book, Making History, which allows the viewing of places in past time but the mechanics are never really explained.

I also remember a letter that was published in a list of various "would-be-usefuls" that members of the public had sent to Tomorrow's World, which said that as energy was never destroyed, just converted why couldn't we work backwards to discover what exactly had happened in the past. The correspondent suggested that they would love to learn what Henry V had really said just before Agincourt. The letter was illustrated with a cartoon with the suggestion that the answer was "Good luck lads! Wish I was coming with you." This is sort of like the idea of a Newtonian computer that calculates the motions and masses of all particles and can therefore work out the future of everything. If it works forwards it just as easily works backwards. Anyway we all know that those pesky little Quanta put paid to that idea but I still wonder if we could pick up something from somewhere.

Genetics already has something akin to this idea in the ability to work backwards to determine single ancestors of entire populations but I cannot see of any scientific discipline which would be able to reconstruct moments like this. It would be the ultimate in forensics.

Isaac Asimov wrote a short story about the creation of a time machine and how its inventor tried to keep it secret simply because he realised that rather than using the device to view the great moments in history it would be used as a shabby reason to determine the truth behind trifling domestic incidents which is of course the truth. I'm currently reading How the Mind Works by Steven Pinker which starts with a loose discussion of robots and general intelligence. Pinker makes a good argument against the necessity of Asimov's laws, saying that no machine really needs to be instructed against evil because it is only humans who have the ability to program evil in to things which is a nice lead-in to the truth that human minds are still many thousands of times more complex than even the best-performing artificial mind. I'm not entirely sure of the argument against the laws of robotics - it must be relatively for a machine to accidentally injure or kill a human and putting some simple overriding fail-safes into the system would guard against this. Maybe Pinker says this later or maybe I fell asleep.