I found this in a 1911 Encyclopedia. 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 ?