The pirate's walk
A group of pirates is heading back to their boat after a night out in the small pub near the harbour. Help them to find their way back home!
The wobbling walk
What a funny group of pirates..have you seen them walking? They are going left and right, back and forth..they seems to be lost!
They take steps of different length totteting in various directions not always aiming directly at the boat!
Think about the traces they left behind - can we predict where they will end? How do we describe this movement? A mathematician would describe it as a
random walk . A random walk is indeed a mathematical description of a path consisting of a set of random steps.
The destiny of a single pirate cannot be specified - a mathematician can not predict if the pirate will reach the boat or not, but he can say more about the
whole crew, estimating the number of successful arrival to the boat.
Fighting randomness with the drift
Imagine you cold drag the pirates despite them trying to go in wrong directions or that while they are cruising in random directions they are the boat siren guiding them to the harbour: this is what is called a drift.
The motion is still governed by randomness but there is a 'tendency' to go in a particular direction.
