# PHYSICS- THE AETHER. Everything you need to know about the mysterious Aether, Michelson-Morley's experient and Einstein's genius answer.

Essay by chrisgayle January 2005

Yr 2004- Research Project 12

SPACE

1. Outline the features of the aether model for the transmission of light. (2)

James Clerk Maxwell proved that light was a wave. Physicists at the time were accustomed to believing all waves must have a medium to be transmitted- like air particles for sound. Because one could not be seen, a model for transmission was invented. Physicist called the medium luminiferous aether and was said 'to carry the motion of light'. It was therefore assumed that the velocity of light, 'c' must be in with respect, or in the frame of reference, to the aether, which was therefore an absolute frame of reference for everything. Aether must have existed anywhere light did and could. The aether model was originally given these features:

- At prefect rest i.e. Completely stationary (absolute frame of reference)

- Perfectly transparent (completely invisible)

- Fills all space

- Insignificant resistance; otherwise objects, like planets, moving through it would loose their energy

- Insignificant density.

Originally thought to be a liquid

- Permeated all matter and was permeable to matter.

- Have great elasticity to propagate light waves.

The proposed features of the aether changed over time. When it was discovered that light was a transverse wave, the aether would have to be solid because transverse waves can only travel in solids, and a solid would be required for the high speed of electromagnetic waves. It was later proposed that the aether changed depending on the motion going through it; wax for electromagnetic waves and liquid for planetary motion. Simply, the aether provided an absolute frame of reference because it was stationary in space, and light had a fixed speed relative to the aether. Simply, it provided an explanation for how light was transmitted.

2. Describe and evaluate the...