Empty space is not empty

PBS TV showed the first episode of Brian Greene's The Fabric of the Cosmos last night. It had the usual Einstein idol worship.

It said that combining space and time into spacetime was greatest idea of all time. When Minkowski published it in 1908 based on Poincare's ideas, Einstein denounced it.

The biggest point of the show was that empty space is not really empty. That's right, it contains the luminiferous aether. Nobody wants to call it that anymore, but that is what it is.

Wikipedia recently considered changing the British spelling "aether" to the American spelling "ether", and rejected the change. I nearly always prefer the American spellings, but I also kept the "aether" spelling in my book. I was mainly quoting Europeans on the subject, and most of them used the British spelling. That spelling also has the advantage that it is not confused with the chemical anesthetic ether.

Here is Maxwell's brilliant Encyclopædia Britannica article on the aether, written before he died in 1879. He used both spellings.

While aether is a dead term, there are advantages to using dead terms. Gauss used to write math papers in Latin because it was a dead language. The spoken languages were not sufficiently standardized for precise work. He could use Latin, and be sure that popular usage will not change the meaning.