…when would humans discovered the principles of relativity?
I’m sure some version of this question has been asked in the rich history of the SDMB, but I couldn’t find it.
Besides the main question, how would our world be different today had relativity not yet been discovered? I know that GPS wouldn’t work without accounting for relativistic effects, but how else?
If anyone called someone “an Einstein” they’d just get a blank look back.
Albert Brooks would have been know by his original name, Albert Einstein.
I am not an expert on this by any means, but it’s my understanding that Special Relativity was “in the air”, and a number of physicists were fiddling around in the area. Einstein was just the first to put it into a coherent, rigorous format. He was the first to publish, but I think historians of science think if he hadn’t someone else would have published something very similar within a few years.
On the other hand, it’s my understanding that historians of science generally think that General Relativity was a truly profound and original breakthrough, and it’s not at all clear that anyone else would have come up with anything similar for decades, or to this day.
Einstein’s did important work on quantum theory too, and Einstein’s absence might have impacted progress there too
“God does not play dice with the universe.”
Wasn’t he wrong about that?
I can’t say. I had a rough time in “Principles of Physical Phenomena”, a quantum mechanics course that was billed as “Not a quantum mechanics course”.
I think Einstein’s work on relativity involved some of the most incredible feats of creative thinking ever made by a human. So I’m not so sure we’d have the same grasp of relativity without Einstein. But I’m no physicist so perhaps the theory was more inevitable that I think.
As for him being wrong about god not playing dice. It looks like he was, but there must still be a very tiny chance he wasn’t.
Didn’t Einstein essentially “give” relativity to the world, instead of reserving it for his own work for a period of time, and this was the reason it was used for the Manhattan project?
So, WWII in the Pacific could have ended some other way-- probably with much greater loss of life of troops on both sides, but with far less devastating effects to civilian populations. And not when in did, but further into the future.
Nuclear warheads probably would have been developed eventually, due to the Cold War, but who is to say by which side?
Julius and Ethel Rosenberg might have died of old age in their beds.
We’d need to come up with another name to call someone when they do something really stupid.
Someone else’s photo would be on the wall above Young Sheldon’s bed.
Einstein published his relativity work, just like any other scientist would. It’s hard to imagine him deciding not to publish. Even if he had withheld his special relativity work for some reason, someone else would likely have discovered enough of it to make the Manhattan Project work - SR was discovered in 1905 - 35 years before the Manhattan Project was founded.
It would have been very uncomfortable for Einstein’s Mom.
Look at the names working on quantum mechanics in the 1920s.
Niels Bohr, Louis de Broglie, Max Born, Paul Dirac, Werner Heisenberg, Wolfgang Pauli, Erwin Schrödinger.
Their body of work was in many ways deeper physics than Einstein, with his limited math, could manage. Do you think that if Einstein hadn’t come up with general relativity they wouldn’t have spent their time cracking that problem? The best go where the deepest mysteries are. They would have been on it like a swarm of bees.
Henri Poincaré discovered the Lorentz transformation and understood the basics of Special Relativity and the equivalence of mass and energy. If Einstein hadn’t existed, Poincaré might have come up with the full theory of Special Relativity, although perhaps not since he died in 1912. Some historians of science consider Special Relativity to be a co-discovery by Einstein and Poincaré. But the ideas were in the air and I’m certain that someone would have continued Poincaré’s work and come up with Special Relativity within a few years of Einstein’s discovery.
I don’t think there is the slightest that special relativity would have been discovered within a few years of 1905. General relativity is an altogether different story. As a matter of fact, David Hilbert discovered the actual equations of general relativity and actually published them just a few days before Einstein. But Hilbert, the leading mathematician of his day, had been in close discussion with Einstein and certainly would not have come up with the idea on his own.
So what would have happened without Einstein. I think that certain time anomalies, differences between clocks on space ships and satellites from those on earth would have made it clear that something else was going on. Also, the thought experiments equating acceleration and gravitational force could have occurred to others. Finally, the drift in the GPS satellites by about 8 miles a day (caused by the clock anomalies) would have alerted them that something was going on.
I imagine people would have (and did IRL) understood well that “something else was going on” long before GPS satellites and temporal anomalies came into the picture. Orbital precession and gravitational lensing and redshift were already being measured near the beginning of the 20th century.
Neither special nor general relativity had much to do with the work to develop nuclear fission weapons. Although the principle of the equivalence of energy and mass is certainly relevant to fission (since the energy from fission comes from the nuclear binding energy that is released in the fission process) this is really the domain of nuclear (particle) physics, with Niels Bohr, Otto Hahn, and Enrico Fermi were really did the foundational theoretical and experimental work which led to controlled nuclear fission, and the ability to calculate the necessary configuration and process for enriching uranium to obtain the rapid fission chain reaction was largely a result of the Tube Alloys program in the UK, later transferred to the Manhattan Project. Albert Einstein’s biggest contribution to the Manhattan Projects was the famous Einstein–Szilárd letter which encouraged President Franklin D. Roosevelt to initiate the fission bomb project as a hedge against Nazi takeover off all of mainland Europe. He later regretted this, both because of the use atomic weapons against Japan, impacting the unarmed civilians, and because of the political belligerence that nuclear weapons were put to.
As @markn_1 noted, the basics of special relativity were already in work, and while general relativity is far more complicated, it seems nearly certain that the principles of what we now term “Einstein gravity” would have been discovered presently, both to explain experimental observation and from the design to better understand the gravitational force. It is perhaps fortuitous that Einstein pressed on general relativity before quantum theory was really developed and accepted, because his (and Hilbert’s) work on the geometric thesis that gravity was a result of the effect of mass on the plenum of space-time as quantified in the Einstein[-Hilbert] Field Equations, whereas physicists starting from the thesis that all forces are quantized fields might have been stuck indefinitely the way we are currently with trying to develop a quantum theory of gravity.
However, the long-neglected original “long form” version of Maxwell’s equations–the twenty quaternion equations of Maxwell’s original formulation rather than the reduced four vector equations that Oliver Heaviside popularized and that are found in electrodynamics textbooks at the undergraduate and lower gradate level today–contain the hints of physics in non-flat space-time, albeit requiring developments in mathematics beyond what was available in Maxwell’s day. For all of his genius and innovation (he is also responsible for the development of color chemical photography, and arguably the basis of statistical mechanics as well as formalizing Michael Faraday’s field thesis of electromagnetism into a rigorous mathematical model) Maxwell was born about three or four decades too early; had he been born later, the advances in both mathematics and the measurement and electrical technology of the late 19th and early 20th century would have potentially allowed him to follow through with many of the theories and potentially have developed both quantum mechanics and relativity in a more comprehensive fashion. I sometimes wonder what we are overlooking from his work that may provide greater insight.
At any rate, if Einstein (or Newton, or Archimedes, or any other figure) were never born, it would not make a difference in the end because physics and natural science is available to be discovered, not invented from some unique creative insight, and the “accident of history” that has some particular figure being the first one to discover and elucidate a physical principle is as much just being in the right place at the right time in terms of the foreknowledge, experimental technology, and the ability to build off of prior knowledge to recognize a new discovery in physical science. Einstein is often celebrated for being a lone patent clerk out of contact with the rest of mainstream physics, but we was well trained in mathematics and physics and his “genius” was as much a devotion to obsessive thinking about the topic as it was special insights or unique abilities.
Stranger
Science most often advances through experimentation I believe. Einstein did not perform experiments of the traditional sort, his experiments were in his mind. I know little about the other leading physicists of the time but I do get the impression they were driven by conventional experimentation, performing tests, evaluating the results, and advancing previously held concepts incrementally. I could be quite wrong about that though.
Were there others who would have likely taken Einstein’s approach of thought experiments?
Were there others coming up with new experiments that would have eventually led to the understanding of relativity through incremental steps?