I'm still trying to absorb #1 and #5. Please Register or Log in to view the hidden image! I always always thought it was Einstein. Are these are correct??? http://discovermagazine.com/2008/mar/20-things-you-didn.t-know-about-relativity 1 Who invented relativity? Bzzzt—wrong. Galileo hit on the idea in 1639, when he showed that a falling object behaves the same way on a moving ship as it does in a motionless building. 2 And Einstein didn’t call it relativity. The word never appears in his original 1905 paper, “On the Electrodynamics of Moving Bodies,” and he hated the term, preferring “invariance theory” (because the laws of physics look the same to all observers—nothing “relative” about it). 3 Space-time continuum? Nope, that’s not Einstein either. The idea of time as the fourth dimension came from Hermann Minkowski, one of Einstein’s professors, who once called him a “lazy dog.” 4 But Einstein did reformulate Galileo’s relativity to deal with the bizarre things that happen at near-light speed, where time slows down and space gets compressed. That counts for something. 5 Austrian physicist Friedrich Hasenöhrl published the basic equation E = mc2 a year before Einstein did. 6 Never heard of Hasenöhrl? That’s because he failed to connect the equation with the principle of relativity. Verdammt! 7 Einstein’s full-time job at the Swiss patent office meant he had to hash out relativity during hours when nobody was watching. He would cram his notes into his desk when a supervisor came by. 8 Although Einstein was a teetotaler, when he finally completed his theory of relativity, he and his wife, Mileva, drank themselves under the table—the old-fashioned way to mess with the space-time continuum. 9 Affection is relative. “I need my wife, she solves all the mathematical problems for me,” Einstein wrote while completing his theory in 1904. By 1914, he’d ordered her to “renounce all personal relations with me, as far as maintaining them is not absolutely required for social reasons.” 10 Rules are relative too. According to Einstein, nothing travels faster than light, but space itself has no such speed limit; immediately after the Big Bang, the runaway expansion of the universe apparently left light lagging way behind. 11 Oh, and there are two relativities. So far we’ve been talking about special relativity, which applies to objects moving at constant speed. General relativity, which covers accelerating things and explains how gravity works, came a decade later and is regarded as Einstein’s truly unique insight. 12 Pleasure doing business with you, chum(p): When Einstein was stumped by the math of general relativity, he relied on his old college pal Marcel Grossmann, whose notes he had studied after repeatedly cutting class years earlier. 13 Despite that, the early version of general relativity had a major error, a miscalculation of the amount a light beam would bend due to gravity. 14 Fortunately, plans to test the theory during a solar eclipse in 1914 were scuttled by World War I. Had the experiment been conducted then, the error would have been exposed and Einstein would have been proved wrong. 15 The eclipse experiment finally happened in 1919 (you’re looking at it on this very page). Eminent British physicist Arthur Eddington declared general relativity a success, catapulting Einstein into fame and onto coffee mugs. 16 In retrospect, it seems that Eddington fudged the results, throwing out photos that showed the “wrong” outcome. 17 No wonder nobody noticed: At the time of Einstein’s death in 1955, scientists still had almost no evidence of general relativity in action. 18 That changed dramatically in the 1960s, when astronomers began to discover extreme objects—neutron stars and black holes—that put severe dents in the shape of space-time. 19 Today general relativity is so well understood that it is used to weigh galaxies and locate distant planets by the way they bend light. 20 If you still don’t get Einstein’s ideas, try this explanation reportedly from The Man Himself: “Put your hand on a hot stove for a minute and it seems like an hour. Sit with a pretty girl for an hour and it seems like a minute. That’s relativity.”
Well...I have issues with Discover magazine. I think that it is one of the worst popular science journals around, at least when it comes to physics. Anyway, I read these 20 points about a month ago, and I THINK that they're all right. As to #1, it is true that Galileo invented the idea of ``relativity'', and that Einstein was very familiar with those ideas. What Galileo thought, though, was that his version of reltivity held for arbitrary velocities. This is not the case, as Einstein showed in 1905---it is only for velocities much less than the speed of light where you can apply the Galilean formalism. So technically Galileo DID invent relativity, but it was Einstein who invented SPECIAL relativity. As for e+mc^2, I'd never heard that when I read #5, but it seems plausible. Soundslike a job for wikipedia...
thanks Ben. And I understand your viewpoint on Discover magazine, but it talks down to my level. Can you suggest another better magazine that I may understand?
Sadly, no. Scientific American is still pretty good, mostly because the articles are written by scientists, and not some dumbass reporter who couldn't hack chemistry class. It's not that Discover magazine doesn't report science, it's just that (as draqon pointed out once to me) these guys are in the business of making money, and they know what makes money. I don't feel like I've ever really read any solid science journalism that's by a journalist.
Well, I've had problems with it since I found out Bob Guccionne Jr runs it. He dated Ann Coulter for crying out loud!!! Anyways, since Galileo didn't know about the speed of light, when was it first remarked upon? Was that Einstein?
I see, some people still aren't able to face the reality..Please Register or Log in to view the hidden image!
Hi Orleander, Galileo is usually said to be the first to try and measure the speed of light. You can read about it here: The Speed of Light. Also on that page near the bottom is a useful snippet about Galilean relativity. I've been kicking around for a while an idea of writing up and posting a tutorial on basic (Galilean) relativity, because it seems that a lot of people struggle with it, and this makes it impossible to handle the ideas developed in Einstein's special relativity. I know that some of the Sciforums anti-special-relativity people are really arguing against the basic relativity of Galileo.
Hi Pete--- If you need help let me know. My boss and I are about to finish a big project, so I should have a little bit of free time.
Don't wait up Please Register or Log in to view the hidden image! I'm flat out for at least the next six weeks.
I find point 2 to be questionable. Most English translations contain the sentence: "We will raise this conjecture (the purport of which will hereafter be called the ''Principle of Relativity'')''... Does anyone have a link to the original German version?
Here's the German article: Zur Elektrodynamik bewegter Körper (deren Inhalt im folgenden "Prinzip der Relativität" genannt werden wird) The paper was translated into English by Lorentz, Minkowsky, and Einstein himself: On the Electrodynamics of moving Bodies (the purport of which will hereafter be called the “Principle of Relativity”)
#5 is a bit of a strech, according to this wiki article. http://en.wikipedia.org/wiki/Friedrich_Hasenöhrl The closest he got was E= 3/4 mc^2, not quite right. He did realize part of the basic equivalence of mass and energy though, that a 'box of photons' would have inertia.
The E=mc² equation had been around before, I think (Heaviside?)... but Einstein's achievement was not in the equation itself, but in the idea of general mass-energy equivalence. A constant factor (such as 2, or 3/4) in the equation isn't a problem - it depends on your choice of units.
Einstein didn't even believe the atom bomb could be created. It took a collegue to convince him. We attribute a lot of things with him, and to blame for this is the press and other sources blowing him out of proportion.
Yes, but the way I read the article, he was off regardless of the system of units, something about the manner in which he handled the boundary I think. The article meantions the "shell", not exactly certain what is meant. Anyway, if you are using a _consistant_ system of units, the constant factor should be 1, not the original 3/8 or later 3/4 that Hasenohrl got. He did apparently 'flirt' with the idea of mass-energy equivalence, at least in that E/M enclosed in a reflecting cavity posessed inertia. I feel generous. Let's give half credit for #5. Please Register or Log in to view the hidden image!
The actual story is that Einstein didn't believe it untill someone explained it to him, then it took him 15 minutes to understand the whole process. Then he wrote a letter to Roosevelt which was the impetus for the Manhattan Project. When Einstein realized the destructive capabilities of the bomb, he wrote another letter to Roosevelt urging him not to use it in the war, but Roosevelt died before he got the letter. This was something he regretted until he died.
Either way, Einstein's legacy would have been assured had he not written the paper on Special Relativity. In 1905 he wrote THREE papers that changed physics, any one of which could have won the Nobel Prize. And the work he did after General Relativity was more or less completely wrong.
