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fys iks!
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Hey i was just wondering where Einstein got the idea for his postulates of the speed of light being the same in all reference frames and that there is no preferred frame.
It's pretty short, so I'll just type it up here.fys iks! said:Thanks for the reply. Does anyone have a link to a derivation of c from Maxwell's equations?
Wow, thanks for the clarification. I knew there was some debate on the issue, but I never knew they later found proof Einstein was aware of it.bcrowell said:The issue of whether MM influenced Einstein is complicated. Einstein claimed that he didn't know about MM in 1905, but later evidence showed that he did know about it, and presumably just forgot that he did by the time he made that statement. The thing is, MM as not considered to be conclusive at the time. People did variations of it, motivated by aether theories, well into the 1920's. E.g., someone did a version in a tent on top of a mountain in an attempt to avoid aether entrainment and obtain the "right" result. Since the experimental situation in 1905 was far more muddled than sanitized textbook history would have you believe, it makes sense that Einstein was more heavily influenced by Maxwell's equations than by empirical evidence on this point.
JustinLevy said:The idea that the speed of light is the same in all inertial reference frames (note it is not the same in all reference frames) came from Maxwell's equations which worked beautifully with experimental data. Possibly also, the Michelson-Morley experiment's null result. Although I've heard some claim historically Michelson-Morley's experiment didn't really influence Einstein ... it is hard to say directly since his 1905 paper didn't give any references.
Eh, I think we may be bordering on debating semantics at this point.yossell said:I'm not sure I understand this. In what sense `came from'? The proof in 9.37PM seem to me to fall short of implying it - for the equations say nothing about inertial frames: they may be taken to hold only in the frame of the aether, and the quantity v, the velocity, interpreted as referring only to the aether. I understood it to be part of Einstein's contribution to explicitly say that the equations hold strictly in *all* inertial frames, and then show how Newtonian equations have to be modified to make this work. Is my understanding wrong?
http://www.fourmilab.ch/etexts/einstein/specrel/www/"A. Einstein said:Examples of this sort, together with the unsuccessful attempts to discover any motion of the Earth relatively to the "light medium," suggest that the phenomena of electrodynamics as well as of mechanics possesses no properties corresponding to the idea of absolute rest.
Jimmy Snyder said:I note the plural "attempts" and therefore consider it unimportant whether or not he knew of Michaelson-Morley specifically.
Einstein's postulates refer to the two principles upon which his theory of special relativity is based. These postulates state that the laws of physics are the same for all observers in uniform motion and that the speed of light in a vacuum is constant for all observers, regardless of their relative motion.
Einstein's ideas were influenced by various sources, including his studies of electromagnetism and the works of physicists such as James Clerk Maxwell and Henri Poincaré. However, his groundbreaking theory of special relativity was primarily based on his own thought experiments and mathematical calculations.
Einstein's postulates challenged the prevailing theory of classical mechanics, which was based on the laws of motion and gravity proposed by Isaac Newton. These postulates introduced a new way of understanding space and time, and ultimately led to the development of the theory of general relativity.
No, Einstein's postulates were met with skepticism and resistance from some scientists initially. It wasn't until later experiments and observations, such as the bending of starlight during a solar eclipse, provided evidence supporting his theories that they gained wider acceptance.
Einstein's postulates have had a profound impact on modern science, particularly in the fields of physics, astronomy, and cosmology. They have led to new understandings of space, time, and the nature of the universe, and have influenced technological advancements such as GPS and nuclear energy. They continue to be a cornerstone of modern physics and have helped shape our understanding of the world around us.