Out of curiousity for any history of science mavens. If Einstein had never been born were there enough other theoretical geniuses around even if Einstein had not derived E=MC squared that some other contemporary would have figured it out in short order or was his discovery that brilliant and insightful that it would have possibly been decades until the pieces fell together for someone else.
Astro, take a breath. You’re making me dizzy.
I think that trends in science were directing things that way, so someone else would have come up with relativity. IIRC, Fotzgerald had already formulated his law of contractions.
I doubt if some one individual would have come up with ALL of Einstein’s results (his paper on Brownian motion, Special Relativity, General Rel., and Specific heat papers). That’s one thing that made Einstein unique. But I don’t think they’d have been long delayed.
You’re right. I’ll try again.
Out of curiosity for any history of science mavens.
If Einstein had never been born, were there enough other theoretical geniuses around, that even if Einstein had not derived E=MC squared, some other contemporary would have figured it out in short order, or was his discovery so brilliant and insightful that it may have been decades until the pieces fell together for someone else?
I agree with Cal. All Einstein did was take the Michelson-Morley results and the already-completed mathematics of Fitzgerald and Lorentz, and assume that instead of the ‘ether’ contracting, figuring that there WAS no ether, and that the dimensions of reality were being deformed in order to keep the speed of light constant. If he hadn’t made that leap, some other scientist would have followed the experimental evidence to the same conclusion – that Newtonian mechanics were flawed and would have to be adjusted.
Einstein’s genius wasn’t so much in the particular revolutionary discoveries he made, as in the fact that he made so many in various different fields of physics. His paper on Brownian motion was an important proof of the existence of molcules, his paper on the photoelectric effect took Planck’s constant and made something physically significant out of it (thus helping to create the very quantum mechanics against which he competed with his relativity), and he utterly reconstructed dynamics, which had been thought to be thoroughly explored and explained since the days of Newton and Laplace.
In science, the bigger the dogma you overthrow, the more famous you become, and Einstein improved on the oldest and most solid of the fields of physics – that’s why he’s still the world’s best-known scientist, 50 years after his death.
I’ve read, and it seems plausible to me, that someone else would have come up with Special Relativity in short order, but that General Relativity would have taken a lot longer. I think it was more of an aesthetic sense that led him there. Of course, that’s also what made him dislike Quantum Mechanics, so it cut both ways.
Einstein was also a part in getting the US to look seriously at developing the Atomic Bomb. He wrote a famous letter that helped goad Roosevelt into action. The letter probably did not do a lot, but it might have started things earlier than they could have. (What if we would have waited until after 12/7/41 to start the Manhattan Project?)
He was not instrumental in the actual design of the Bomb, though.
Like ZenBeam said, the stage was set for Special Relativity, and all it took was someone to put the pieces together. Of course, even if that was all Einstein did, he’d still be regarded as great for it, but not nearly to the degree that he actually is. Likewise, his work in quantum mechanics and thermodynamics probably could have been done not too long after when he did it.
On the other hand, Einstein really does deserve all of the credit for the general theory of relativity. Sure, Riemann geometry had already been around for a while, but who would’ve guessed that it had anything to do with gravity? Were it not for Einstein, we probably still wouldn’t have GR.
Another point, is that even if someone else had discovered SR, and explained Brownian motion and the photoelectric effect, it probably wouldn’t have been the same person to do all of them. Because Einstein made major contributions to all fields of physics, he served to hold the physics community together: Nobody but Einstein could have had the influence to get the ball rolling for the Manhattan Project, for instance, or to sponsor DeBroglie’s ideas on wave-particle duality.
and he’s so quoteable! 
I agree, although a lot of people point to Hilbert’s paper on general relativity, presented just a few days after Einstein’s. Hilbert had extensive communication with Einstein, at the time.
I think you may be making general relativity seem harder than it is. The tensor math may be obscure, but the concept is very simple: Einstein took the observational fact that gravitational mass and inertial mass are ALWAYS equal, to any precision you like, and saw gravity for what it was – a fictitious force, like the Coriolis force, caused by your choice of co-ordinate system. (Until then, the fact that gravitational and inertial mass were equal was simply an unexplained coincidence – interestingly similar to the thread about relativity on the Columns board, eh Mentock?)
It wasn’t that big a leap – fictitious forces are always proportional to inertial mass, because in a properly chosen reference frame, they are just manifestations of inertia. And as stated above, much of the math for non-Euclidean geometry had been around since the mid-1800s, and Einstein himself had expanded the number of dimensions to four with his special relativity, so constructing a gravitational theory based on non-Euclidean four-dimensional geometry was just a matter of redefining some basic principles and synthesizing several existing fields of mathematics. Not EASY, but not something someone else wouldn’t have done eventually.
That’s what makes science the most fundamental of human endeavors – it’s not dependent on any one person or any one experiment. Even if Einstein had never existed, our systematic investigation of the Universe would eventually have revealed the features he discovered.
The equivalence principle was one of his three cornerstones–the other two were general covariance, and Mach’s principle. No other individual would have latched onto that weird combination–and it’s only our great hindsight that allows us to see how “easy” it was to derive general relativity.
I’d say we’d have some sort of advanced physical theory, but it probably wouldn’t be general relativity. Dicke once did a what-if type analysis, and showed that if Einstein had been even six years late with publishing his paper, it probably would have been swept under the rug. Of course, if anyone else had concocted it, they wouldn’t have received even that much consideration.
Essentially, Dicke’s paper showed that other theories can produce similar results, and other researchers were on track to produce those other theories. Once they were verified, to suitable precision, it would have been very hard for Einstein’s theory to knock them off. Those other theories share none of the concepts of Einstein’s theory, so they truly are different.
Gravity a fictitious force? Urrrrrr…all confused now. Then what holds me down to the planet other than my big behind and a lack of morning coffee?
If Einstein had never existed, mankind would hae been forced to invent him.
(Sorry. Somebody had to say it.)
astro: The fact that a force is fictitious has nothing to do with whether it SEEMS real. Have you ever ridden in one of those midway rides where you stand against the wall of a cylinder and get spun around? There’s a very real force that pins you to the wall – just as real as gravity – but if you look at the machine from outside, you’ll see that this ‘centrifugal force’ is just your own inertia, which wants you to carry on in a straight line instead of spinning in a circle. Similarly, the force we think of as gravity is nothing but our inertia, our tendency to carry on moving in a straight line – only, according to general relativity, the presence of mass causes all of the straight lines to be rather bent, curving our paths and creating the gravitational ‘force’ we know and love.
Why does it matter whether you think of gravity as a force or an effect of your reference frame? At a gross level, it doesn’t; that’s why students are still taught Newton’s gravitation: the math is much simpler and the approximation to reality is excellent, if not quite perfect. But Newton’s theory didn’t predict Mercury’s orbit perfectly (the problems showed up in Mercury because of its proximity to the massive Sun), nor did it predict that light would be deflected by gravity, or redshifted by it. Einstein was also bothered by the spukhaftefernwirkungen (spooky action-at-a-distance) of it all – Newton’s theory is about fields that stretch throughout all of space and never disappear completely, so a proper prediction of the path of any body would require a knowledge of the position and mass of everything else in the Universe. Einstein replaced that action-at-a-distance with a local effect, a local curvature of space-time. Not so spooky, but a lot harder to calculate…
Actually, Newtonian physics does predict that light will be deflected by a massive body… If you calculate the orbit of a particle, you find that it’s independent of the mass for any nonzero mass, and it’s not too much of a stretch to say that it’d be the same for a zero-mass particle like a photon. The key is that the deflection predicted by GR is exactly twice that predicted classically, and this is the amount of deflection observed.
By the way, PaulT, what’s your field? You seem to be focusing on relativity threads so far… Am I to assume that I’m no longer the only relativist on the board? Welcome aboard, in any event.
How about:
If Einstein never existed, you wouldn’t be asking this question.
Chronos…fair warning…you keep this “relativist” stuff up and I’m going to post the lyrics to “I’m My Own Grandpa”.
If Einstein never existed we’d all be speaking German now under a Nazi dictatorship.
Boy, that’s a scary thought!
How do you figure that?
ZenBeam, what kind of ignorant lame-o are you? the only reason that WWII ended was because of a man-to-man fistfight to the death between Hitler and Einstein in Adolf’s secret bunker built into a volcano in Berlin.