Comments on: Einstein’s Discovery of General Relativity, 1905-1915

By: New Einstein Letters - Asymptotia

New Einstein Letters - Asymptotia — Mon, 29 Jan 2007 23:47:07 +0000

[...] I’m not supposed to be blogging, since I’ve got to go and set up and introduce the visiting speaker, but I thought I’d point you to an LA Times (front page!) article by John Johnson, talking about some new material about Einstein and his more “human” side, as opposed to the standard image that is portrayed*. The letters (from about 1915, before the completion of his General Theory of Relativity – see a post I did about that work here) speak of more humanity, more vulnerability, insecurity, doubt… Yes, all those things that the rest of us have. No surprise to some of us that Einstein shared them too, but definitely good to have more “out there” to paint a better picture. I’ve not read the article in its entirety (just skimmed it so far), but it certainly looks interesting, and will point you to more material. The article is here. [...]

By: M. Ayub Faridi

M. Ayub Faridi — Sat, 25 Mar 2006 13:10:44 +0000

In 1905 Einstein merged space and time to get the stage on which Dynamics- spacetime has been played. Introducing the curvature, the merger became “unification” in Einstein’s General Theory of Relativity of 1915. In this process, the original Dynamical concepts were replaced by Field Theoretical concepts for that part of Dynamics to which General Relativity is applied â€” namely Gravity. However, there was no truly relativistic theory that incorporated gravity and other interactions in a Unified Field Theory. Einstein spent the better part of his life trying to construct such a theory to his satisfaction. Why was he dissatisfied with the unification is apparent in, for example, the Reissner-Nordstorm solution? The essence of the problem is that in the general equations of motion, gravity is incorporated into the left side of equations while the other interactions appear on the right. The left side contains gravity while the right embodies the rest of Dynamics. One might say that, “the seam shows through” here. This problem of unification becomes really acute when attempts are made for the quantistion of field.

By: KC on Mathematics and Strings | Cosmic Variance

KC on Mathematics and Strings | Cosmic Variance — Sun, 12 Mar 2006 15:46:46 +0000

[...] In the commentary, she tries to counter the accusations made that string theory is all nonsense because it is just “mathematical navel-gazing” with no connection to reality. She does this by pointing out -quite correctly, I think- that it should not be forgotten that there’s quite a history of marvellous scientific discovery coming straight from consquences of puzzling over mathematical structures. She gives the example, among others, of Dirac’s discovery of anti-matter, which essentially came from wondering what was the meaning “the other sign choice” after taking a square root. (At this point, I’ll also point you to a post I did last November about Einstein’s decade of struggle to formulate General Relativity. Note: Anti- and Pro-string crowd: Let’s try to go and read that discussion thoroughly before endlessly repeating old arguments all over again on this thread, ok?) [...]

By: The Greatest? Einstein’s GR | Cosmic Variance

The Greatest? Einstein’s GR | Cosmic Variance — Mon, 09 Jan 2006 06:44:55 +0000

[...] This is Einstein’s 1916 General Relativity paper. A strong contender from the man who had the whole year to himself in 2005. (I did a post about some of this work’s development here.) [...]

By: The Greatest Physics Paper! The Vote | Cosmic Variance

The Greatest Physics Paper! The Vote | Cosmic Variance — Mon, 09 Jan 2006 06:41:56 +0000

[...] (Einstein’s 1916 General Relativity paper. A strong contender from the man who had the whole year to himself in 2005.) (I did a post about some of this work’s development here.) [...]

By: Mark

Mark — Sat, 17 Dec 2005 04:22:14 +0000

Thanks! I knew that I knew the person involved (Pedro Ferreira as it turns out), but still couldn’t remember the article.

By: Count Iblis

Count Iblis — Sat, 17 Dec 2005 01:57:45 +0000

I found the article: Constraints on the Electrical Charge Asymmetry of the Universe

By: Mark

Mark — Fri, 16 Dec 2005 17:47:00 +0000

I vaguely recall something similar, but don’t recall the details.

By: Count Iblis

Count Iblis — Fri, 16 Dec 2005 13:35:04 +0000

Mark, I vaguely remember a recent article that derived bounds on the charge difference of protons and electrons. The idea was that a small charge difference would have cosmological effects that were ruled out by WMAP. The new bounds were many orders of magnitude stronger than previously known bounds

By: Mark

Mark — Fri, 16 Dec 2005 13:02:55 +0000

Ashley. Because they have exactly the same number of negatively charged particles (electrons) as positively charged ones (protons). So as long as you’re not too close to an atom (and by atoms’ standards, we’re almost always far away from them) the two effects cancel and you see something with no charge at all.