For an explanation, see the main splats page
The principles of magnetism
- A magnet has the power of attracting magnetic material like iron. A given pole of a magnet will attract an unlike pole and repel a like pole.
- Magnetic forces of attraction and repulsion pass through wood, paper and flesh without any measurable effect, and can operate on the other side.
- Many aspects of magnetism can be explained by lines of force. Lines of force do not exist, but they are a convenient 'fiction' that we continue to use.
- A magnet can induce magnetism in a piece of iron if it is manipulated properly. The most common method of magnetizing iron is by stroking to align the domains.
- A moving magnetic field makes a current flow in a conductor. So does a changing magnetic field. This is the basis of electromagnetic induction.
- The Earth's magnetic field experiences polar reversals from time to time, as shown by 'frozen' magnetic particles in igneous rocks which remain as a record.
- Many animals have a magnetic sense. Birds seem to use the Earth's magnetic field to navigate, from experiments where they are fitted with magnets or weights.
- The most recent reversal of the Earth's magnetic field, known as the 'Jaramillo Event' is calculated to have happened somewhere around 900,000 years ago.
- In 1832, Karl Gauss, whose name is now attached to one of the basic units of magnetism, put together a consistent set of units for use with magnetic effects.
- In 1948, Alpher, Bethe, and Gamow considered a rapidly expanding and cooling universe and suggested the elements were produced by rapid neutron capture.
- In 1895, Pierre Curie described how magnetization is proportional to magnetic field strength, and how magnetism is lost at high temperature, the Curie point.
- In 1750 John Michell stated that the inverse square law applied also to magnetic fields, and described magnetic induction, extending the operation of the law.
- A paramagnetic molecule is attracted by a magnetic field, while a diamagnetic molecule is repelled by a magnetic field.
This file is http://members.ozemail.com.au/~macinnis/scifun/, first created on February 20, 2009. Last recorded revision (well I get lazy and forget sometimes!) was on February 20, 2009.
©The author of this work is Peter Macinnis, who asserts his sole right to the product as it is packaged here, recognising that many of the ideas are common. You are free to use this as a model to do your own version. Copies of this whole file or site may be made and stored or printed for personal or educational use. You can contact me at email@example.com, but only if you add my first name to the front of that email address -- this is a low-tech way of making it harder to harvest the e-mail address I actually read.
This site had 219,000 hits on the index page from 1999 to January 2007 and an unknown number on other pages. In January 2007, a combined counter was placed on all of the pages, counting page hits which now total