I found this in a 1911 Encyclopedia.(adsbygoogle = window.adsbygoogle || []).push({});

The energy in sunlight per cubic cm. just outside the earth's atmosphere is therefore about 4Xio~5 ergs; applying the law of inverse squares the value near the sun's surface would be 1-8 ergs. Let E be the effective elasticity of the aether; then E = pc2, where p is its density, and c the velocity of light which is 3X10 10 cm./sec. If £=A cosu (t-xlc) is the linear vibration, the stress is E d£/dx; and the total energy, which is twice the kinetic energy Jp(d£/dt)2dx, is fp«2A2 per cm., which is thus equal to 1-8 ergs as above. Now \=2irc/n, so that if A/X=£, we have 5p(2Tc&)2 = i-8, giving p=io~i2/fe~2 and E = lo"1^"2. Lord Kelvin assumed as a superior limit of k, the ratio of amplitude to wave-length, the value lo"2, which is a very safe limit. It follows that the density of the aether must exceed io~18, and its elastic modulus must exceed io3, which is only about io~8 of the modulus of rigidity of glass.

And i have absolutely no clue what 95% of it means. That math looks alien to me... and math hasn't looked this alien since I was in grade school.

Any body good at this stuff ?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# What does all this mean ?

**Physics Forums | Science Articles, Homework Help, Discussion**