> O Oracle most wise, whose attention to detail is unmatched,
> whose head for figures is as big as the day is long, I
> have a question.
> There are 16 wires that go through an pipe under a river and come out
> the other side. However, no-one knows which wire-end on one side
> corresponds to any wire-end on the other side. There is a battery on
> one side of the river, the side you start on. The river is one
> kilometer wide. Your job is to find out which wire-ends correspond.
> You may consider the job finished when you know about all of the
> wires; it does not matter which side of the river you're on.
> You can determine whether two wire-ends are connected by passing power
> from one end, then checking the other end to see whether it's turned
> on. The problem is that that you don't have the tools necessary to
> hook the wires up to the generator or to each other. For that you
> need an electrician. You can find out whether a given wire is "live"
> by grabbing it and sticking your foot in the water. But to actually
> change any connections, you need an electrician.
> The only electrician available happens to be a cannibal. If, at any
> time, you and he are alone together on land and you are unarmed, he
> will kill you and eat you. If this happens, you are considered to
> have failed in your task. You are not allowed to kill the electrician
> or take his tools, as this would be a violation of the prime
> directive. The electrician weighs 70kg and starts on the same side of
> the river that you do.
> You have one weapon, a shrimp fork. As long as you wield it, you are
> safe from the cannibal electrician. The shrimp fork weighs 1 kg (it's
> for very large shrimp). It starts in your possession. If you ever
> leave the electrician alone with the shrimp fork, he will steal it.
> The electrician wants to be able to bill you accurately, and will do
> no work unless in the presence of a sundial (he does not know how to
> read a clock). That is, he must be on the same side of the river as
> the sundial. You only have one sundial available. It weighs 40 kg.
> Your only way to cross the river is by means of a boat. The boat is
> capable of carrying you plus 100kg. Only you know how to work the
> boat. No matter how weighed down the boat is, it travels at 1
> kilometer per hour. Note that if you drop off the electrician on one
> side of the river and immediately leave for the other side, that does
> not count as being alone with the electrician on that side of the
> river--you must disembark from the boat before he will try to eat you.
> Whenever the boat is in motion, it attracts the attention of the 30 kg
> giant flying tarsier. The tarsier, which starts out on the same side
> of the river that you do (in its nest), flies at 4km/hour. It flies
> from its nest to the boat, alights on the boat, then immediately flies
> back to its nest, from there back to the boat, and so on until the
> boat next comes to rest. Note that if it alights on the boat and the
> boat cannot support the tarsier's weight, the boat will sink.
> However, if at least ten of the wires have power in them, the tarsier
> will not land in the boat, fearing to get too close to the wires (it
> fears low frequency EM radiation). It will still fly back and forth,
> Assuming you make the minimum number of trips possible to complete the
> task, how far will the tarsier have flown by the time you're done?