New paper, by some Brazilians:
The Fourth Dimension: From its spatial nature in Euclidean geometry to a time-like component of non-Euclidean manifolds
José Maria Filardo Bassalo, Francisco Caruso, Vitor Oguri
In this article, the evolution of the ideas about the fourth spatial dimension is presented, starting from those which come out within classical Euclidean geometry and going through those arose in the framework of non-Euclidean geometries, like those of Riemann and Minkowski. Particular attention is given to the moment when real time is effectively considered as a fourth dimension, as introduced by Einstein.
This is a nice history of attempts to go beyond three dimensions.
Like other such historical works:
1. There is no mention of Poincare, or the fact that he was the first one to treat time as the fourth dimension, in the context of relativity.
2. The authors go out of their way to attribute credit to Einstein. It is always "Einstein’s Special Relativity".
3. It cites Lorentz, but always to badmouth his conceptual understandings somehow.
I don't want to pick on this paper, as it is just doing what everyone else does. The authors are from Brazil, so there is no good reason for them to be partial to Einstein. But they are.
This is so bizarre. There is no necessity for a historical discussion to get bogged down with issues of credit, but the relativity stories always do, and always give nonsensical reasons for crediting Einstein.
In this case, it says that Lorentz did not understand that the "local time" of an electron he invented in 1895 was really just the time that is local to the electron.
Huh? Isn't that what Lorentz called it?
Lorentz won a Nobel Prize in 1902, in part for his electromagnetic relativity theory, and in part because Poincare recommended that he get it for his ingenious invention of local time. Poincare certainly understood it at the time, even if Lorentz did not fully. Poincare used it as the fourth dimension in 1905.
Einstein adopted the concept of Lorentz's time in 1905, but not as the fourth dimension. He only did that after Minkowski and everyone else used it in 1908. Einstein did not really have any understanding of relativity that was any better than Lorentz's, until he learned Minkowski's in 1908.
I wrote a book about this, but never really found a good explanation for this Einstein worship. Obviously these Brazilians are educated enough that they know the story. They could just read Wikipedia, and see that nearly everything is due to Lorentz, Poincare, and Minkowski. If they were unsure, they could have avoided giving credit to anyone. I don't know why they insist on crediting Einstein for what Lorentz and Poincare published earlier.
One thing I learned from the above paper is that the Italian artist Giotto discovered that the sky was blue about 700 years ago. Byzantine art portrayed a golden sky. Apparently gold symbolized heaven, and the symbolism was more important than the chromatic accuracy. Many older books tell about the sky, but never mention that it is blue.
I don't know what to make of this. Did the sky change color 700 years ago? Did ancient men never bother to look up and notice the sky? Did they not have any blue pigments for making paint? Was it cloudy all the time? I have heard also that ancient men did not notice that the ocean is blue, and described it as other colors. Did they have some mental refusal to accept the color blue? I have no idea.