Friday, 24 May 2013

The Turk

Whilst watching a recent episode of Doctor Who I was reminded of The Turk. The Turk (or Mechanical Turk) was a fake chess-playing machine first constructed in Vienna in 1770, to impress the Empress Maria Theresa of Austria.

The presenter, Wolfgang von Kempelen, and later Johann Maelzel when he purchased the machine in 1804, would assemble a paying audience, open the doors of the lower cabinet and show an impressively whirring clockwork mechanism that filled the inner compartments beneath the seated figure. Then he would close the cabinet, and invite a challenger to play chess.

The thing was a sensation.

Before it was destroyed by fire in New York in the 1850s, it played games with everyone from Benjamin Franklin to Napoleon Bonaparte. In the 84 years the Turk was in use, it was almost unbeatable. The operator during Kemplen's original tour remains a mystery, but when exhibited by Malzel, the machine was operated by ordinary chess players.

The public at the time truly believed artificial intelligence had arrived on earth. The Turk was, of course, a fraud. It was a clever magician's illusion, with a sliding sled that fitted inside the lower cabinet and allowed the hidden chess player to slide easily, and most importantly, silently into the machine's lower compartments. The cabinet actually had a lot more free space then the clockwork machinery suggested.

The interior of the machine was very complicated and designed to mislead those who observed it. The design allowed the presenter of the machine to open every available door to the public, to maintain the illusion. The operator actually sat on a sliding seat and moved through the machine as the operator opened and closed each door, thus evading observation.

The chessboard on the top of the cabinet was thin enough to allow for a magnetic linkage. Each piece in the chess set had a small, strong magnet attached to its base, and when they were placed on the board the pieces would attract a magnet attached to a string under their specific places on the board. This allowed the director inside the machine to see which pieces moved where on the chess board. The internal magnets were positioned in a way that outside magnetic forces did not influence them, and Kempelen would often allow a large magnet to sit at the side of the board in an attempt to show that the machine was not influenced by magnetism.

An operator inside the machine also had tools to assist in communicating with the presenter outside. Two brass discs equipped with numbers were positioned opposite each other on the inside and outside of the cabinet. A rod could rotate the discs to the desired number, which acted as a code between the two.

Another part of the machine's exhibition was the completion of the knight's tour, a famed chess puzzle. The puzzle requires the player to move a knight around a chessboard, touching each square once along the way. While most experienced chess players of the time still struggled with the puzzle, the Turk was capable of completing the tour without any difficulty from any starting point on the chessboard.

I find the Turk fascinating for several reasons. Firstly, it displays an odd, haunting hole in human reasoning. Common sense should have told the people who watched and challenged it that for the Turk to have really been a chess-playing machine, it would have had to have been the latest in a long sequence of such machines. For there to be a mechanical Turk who played chess, there should have been several generations of more basic chess-playing machines.

It's true that the late 18th Century was a great age of robots, machines that could make programmed tapestries and mechanical birds that could sing. In large part, I think people were fooled because they were looking, as we always seem to do, for the beautiful and elegant solution to a problem, even when the cynical and ugly one is right.

What also interests me is that it turns out that the chess players who operated the Turk from inside were just chess players, an ever-changing sequence of strong but not star players, who needed the work badly enough to be willing to spend a week or a month inside its smoky innards. Maelzel picked up chess players on the run, wherever he happened to be.

The Turk is a fantastic piece of machinery that fooled thousands during the 1800s, and whilst nowadays we have computer chess players and robots who can play chess, I think the Turk stands out for its ingenious design at the time.