I agree that if they had never been born, their discoveries would have been made by someone else. But not necessarily at the same time or place. Which could have a significant (butterfly) effect on how history played out.
This thread’s OP assumes that Einstein’s discoveries would have been made eventually, but asks how long it would have taken.
Many, many smart people after Einstein have done work requiring GR and SR. Without Einstein in the picture they would have worked with “only” all the work Einstein built on, and some of them are likely to have produced part or all of GR and SR in his place.
With special relativity I think someone else (probably Henri Poincaré but there were others thinking along the same lines) would have figured it out. With regard to general relativity (e.g. the geometric field theory of gravitation) would have taken longer because nobody else was really working on it, but Newton’s “Laws”, while workable for normal observations are manifestly incomplete and more importantly lack an actual mechanism of action, so it would have become obvious that it was incomplete especially with advances in astronomy and astrophysics. Whether someone would have gone down the path of a geometric field theory versus trying to quantize it the way that the electromagnetic and nuclear forces are is a more substantial question, because going down that path has not been fruitful despite several decades and increasing sophistication of mathematical methods in quantum field theory. We can’t really guess how long or who might have formulated something like the Einstein[-HIlbert] Field Equations because they just weren’t in the mainstream, but enough people have come along since with substantial advances to general relativity that it seems likely someone would have worked out something like the theory.
Actually, the experimental method as applied to science is a recent innovation of the Enlightenment period and prior explorations into “natural philosophy” were largely thought experiments that were performed “in the mind”, as is most of advanced physics including M-Theory and (with computer simulation) cosmology without any kind of direct observation or experiment.
Stranger
Would this apply to Einstein’s contemporaries?
OK, that was funny.
Without Einstein, would we have two separate theories, GR and SR? Or would they have gotten incorporated into one big messy thing?
The special [theory of] relativity, as the name implies, is a special (reduced) case of general relativity; specifically in a region in which the curvature of spacetime is essentially zero, also known as a Minkowski space in which the geometry is Euclidian (three orthogonal spacial dimensions). Special relativity was discovered first (and was just called ‘relativity’) because it was mathematically simple, actually technically requiring algebra, although Einstein did use some partial differential equations in “On the Electrodynamics of Moving Bodies” (English translation here). Presumably any workable formulation of general relativity would be reducible to special relativity even if it weren’t formulated in the tensor form of the Einstein Field Equations.
Stranger
It does? I’d be interested in hearing that story (i. e. reading it, if it’s written up somewhere)—naively, I would’ve thought that because of the close connection between the (complexified) quaternions and Minkowski space, you’d have an even harder time moving to a non-flat spacetime starting from a quaternionic formulation.
All the Einstein kids would have been orphans!
Okay, just putting out names here, off the top of my head, how about Shakespeare or Jackson? Gotta admit, they both have a good sound to them. Other suggestions are welcome!
Maybe I’m just being a Shakespeare but I can’t think of who the supersmart Jackson is.
Curtis “50 Cent” Jackson.
Well, he’s the first name that pops up after googling “smartest Jackson”.
I figured @Lucas_Jackson who was being quoted.
It would go for the old No shit, Sherlock!
Einstein came up with Special Relativity on his own (the largest shoulders he was standing on were Maxwell’s), but as others said, many others were doing work that led in that direction. Any of them could have figured it out, especially once the Michelson-Morley experiment became widely known (it was done before Einstein’s publication, but he probably didn’t know of it). Heck, if he’d lived long enough, Maxwell himself probably could have done it.
General Relativity, there were a few pieces floating around, but nobody but Einstein was close to putting them together. If it weren’t for Einstein, we’d surely have figured it out by now, but it probably would have taken at least well into the space age.
In quantum mechanics, Einstein did make a few early contributions, but the two heavy lifters were Heisenberg and Schrödinger, and I can name quite a few more whose contributions were greater than Einstein’s. In fact, I’d argue that Einstein’s biggest contribution to quantum mechanics was in recognizing de Broglie’s contribution: Other scientists took him a lot more seriously once Einstein was backing him.
In nuclear physics, Einstein’s only real contribution was in the letter to Roosevelt encouraging the Manhattan Project. Yes, yes, nuclear weapons illustrate E = mc^2, but that comes out of special relativity, which (as mentioned) was well before then, and would surely have been developed by someone else, and even if you didn’t know the relation between matter and energy, it’s easy to see empirically that there’s a whole lot of energy available there, and it’s all too easy to make the jump from “whole lot of energy available” and “bomb”.
Yes. Many of the big names in QM were theorists.
Oh, right, I meant to comment on that, too. Of the great names in science, some were experimentalists, and some were theorists. You need both, and there’s something of a tendency for the really great ones to alternate: Each great experimentalist leads to a theorist explaining their observations, and each great theorist leads to an experimentalist finding ways to test the boundaries of their theories.
Thanks to both of you. I was hoping someone would follow up and flesh that out.
cough cough Ahem…
You darn tootin’, Newton!
Sorry, man. I forgot about your work on quantum insolvency and multiphasic spasmodic incandescent osmosis. You broke trails and lots of glassware.