Talk:Magnetic pendulum

Talk:Magnetic pendulum

I found this entry while looking for info on the three magnet pendulum. This entry does not mention the most interesting feature of the three magnet pendulum when properly set up which is that it behaves in a mathematically chaotic manner in that the end state cannot be predicted. The slightest variation in the starting position will give a different end position.

This article needs tidying up. For instance it describes its construction using a "thread" then a "rope". In fact it can me made of a rigid structure provided it can pivot freely in any lateral direction. The pendulum bob can be made of any ferrous metal or indeed can be another magnet.
The interesting and usual arrangement is such that the magnetic pendulum bob can be attracted to three fixed magnets with three stable positions over each fixed magnet. However, any number of fixed magnets can be deployed to give a complex oscillation pattern.
The usual arrangement, as mentioned above, is tri-stable with the pendulum being equally attracted by the fixed magnets strongly enough to eventually settle in a stable position attracted by one magnet. It is this configuration which demonstrates mathematical chaos as in practice it is impossible to predict the pendulum final position.

Keoka (talk) 04:11, 31 January 2014 (UTC)

Need for rewrite

Quote: A magnetic pendulum is an experiment where a metal ball on a thread (a pendulum) can be influenced by a number of magnets on the ground. It is often used to demonstrate *Chaos theory*.

An apparatus cannot be an experiment. This is as science entry and needs clarity. A pendulum is an apparatus which needs a description and is used in experiments.
I am putting together a rewrite of this article which not only describes a three magnet magnetic pendulum, but how one is used to demonstrate chaos theory, all in simple language. I will also have relevant references.
I shall post the rewrite first on these talk pages for comments.

Keoka (talk) 19:58, 31 January 2014 (UTC)

Suggested rewrite

The magnetic pendulum suspension or pivot permits free movement in all directions. The pendulum weight (or bob) is made of a magnet or a metal such as iron which is attracted by one or more magnets which do not come into contact with it. Typically three equally spaced fixed magnets are put below the pendulum bob, and close enough to attract the bob over the closest magnet when at rest.

When the magnetic pendulum is set swinging, it describes a very complex path around all three magnets. This path, and the magnet which it stops at, cannot be predicted. This is pure chance, called in mathematics "Chaos theory". However carefully the pendulum is set swinging from the same place, it is not possible to say where it will stop as this is just chance.

The reason for this is that very small changes in the starting position, and movements of the air, are amplified with each swing. As a result, the pendulum movements become random.

Keoka (talk) 23:31, 1 February 2014 (UTC)

Hi Keoka! You probably won't get much of a response here, if you're waiting for one. Talk pages on this project don't see a lot of activity. It sounds like you know what you're talking about, so you could just go ahead and rewrite the article. There aren't any references on the page so I don't think anybody will disagree with your rewrite. Osiris (talk) 04:32, 2 February 2014 (UTC)