Marcel Grossmann and his contribution to the general theory of relativity | Hacker News Reader

Marcel Grossmann and his contribution to the general theory of relativity

ar5iv.labs.arxiv.org

75 pointsjoebig33 comments

One of Grossman's bound, beautifully handwritten notes, many which were once used by Einstein to get through university exams: https://www.e-manuscripta.ch/zut/content/titleinfo/146744

I'm not sure how he writes pages and pages like that, without even crossing out a word because of a mistake? I feel like he must have re-written some of these notes afterwards, but even then, how do you never make a mistake?

I think most likely the notes were the result of re-processing information written down earlier -- if the original content was taken from a class. Nevertheless, that is very impressive -- almost a product of art. I wish I could get one copy.

My parents can write like that (or could when they were not in their 90s yet). School back then put a lot of emphasis on good handwriting.

I on the other hand have handwriting that's barely legible after decades of typing on keyboards.

My notes looked like crap almost always, but I knew some girls in university where notes looked good while writing and then exactly did this rewriting for perfectionism (and besides that, this written reiteration is likely quite good to ingrain it, like spaced learning).

Any such notes are most likely rewritten form of rougher notes written elsewhere. Then again, it's not difficult to write without making a mistake.

Think about musicians who improvise for quite a long time, playing hundreds of bars, while never playing a wrong note.

After I read Moonlighting with Einstein (about mnemonics), I wondered how throughout the ages, technologies shaped the way we think and structure thoughts. This closely relate to it. I assume a 100 years ago, academic had far larger memory capacity than the average peer in today's world. We kinda traded memory for higher CPU frequency (or maybe just decreased our memory, maybe our software is digressing). But this could explain why the chain of thought was so clear to never make a mistake? I wonder if there is a research on this fascinating topic.

A bit of survivorship bias in your question.

You are comparing the absolute best from 100 years ago with the average peer from today.

There were also far far fewer "researchers" back then.

An excellent read to celebrate π day :-)

The story of how the mathematics of general relativity were put together is one of the well documented insights into how the human intellect incrementally tackles understanding reality around us. Physical intuition (here represented by Einstein) and mathematical structure (embodied in Grossmann) dance around before (occasionally) landing into a magical place that somehow turns out to be "true".

Neither intuition about how nature works nor mathematical skill are sufficient conditions for this to happen. If you read to the end you'll learn briefly about "teleparallel" attempts at gravity/electromagnetism unification - which is just one of the many failed subsequent attempts of Einstein to extend his intuition one further step.

Something that is not covered in much detail is how much Grossmann knew of and appreciated Riemann's work and thinking. Decades prior, Riemann already thought that the geometry of (three)-space is something to be determined experimentally.

If you want to talk about contributions to the general theory of relativity, why not talk about the people that Einstein is alleged to have plagiarized, Henri Poincaré, David Hilbert and Hendrik Antoon Lorentz?

Neither Poincare nor Lorentz are relevant to the genesis of General Relativity. The only relevant priority dispute is whether Einstein or Hilbert wrote down the correct field equations first. This was after a long correspondence between the two, in which Einstein explained his ideas -- there is no dispute that Einstein "invented" General Relativity. See https://en.wikipedia.org/wiki/General_relativity_priority_di...

> Neither Poincare nor Lorentz are relevant to the genesis of General Relativity

Well, that's just plain wrong. From the horse's mouth:

> As we know, this is connected with the relativity of the concepts of "simultaneity" and "shape of moving bodies." To fill this gap, I introduced the principle of the constancy of the velocity of light, which I borrowed from H. A. Lorentz's theory of the stationary luminiferous ether, and which, like the principle of relativity, contains a physical assumption that seemed to be justified only by the relevant experiments