geordief Posted December 30, 2019 Posted December 30, 2019 (edited) Does GR have anything to say about particle physics? When two particles collide is it just a case of going through the debris and looking for new objects or are there simple collisions where it is possible to predict when the initial conditions are known? I am reading through Einstein's Popular Exposition and have come across this quote "The only statements having regard to these points which can claim a physical existence are in reality the statements about their encounters. In our mathematical treatment, such an encounter is expressed in the fact that the two lines which represent the motions of the points in question have a particular system of co-ordinate values, x1, x2, x3, x4, in common" https://www.bartleby.com/173/27.html which seems to describe the "collision" of two world lines... (I am also learning that AE was a strong user of hallucinogenetic drugs and am quite astonished not to be aware of this until now https://vocal.media/futurism/11-things-you-may-not-know-about-albert-einstein I researched this when I came upon his introduction of the "reference-mollusk" description in his book and thought "hold on a second here....what?" https://www.bartleby.com/173/28.html "This non-rigid reference-body, which might appropriately be termed a “reference-mollusk,” is in the main equivalent to a Gaussian four-dimensional co-ordinate system chosen arbitrarily" and thereafter ) Edited December 30, 2019 by geordief
Mordred Posted December 30, 2019 Posted December 30, 2019 Though particle physics uses GR GR itself only plots the worldline paths of particle momentum. Which is why I always get a kick out of people discounting GR because it didn't predict dark matter or dark energy. It's not the function of GR to predict the particle model only how particles move in spacetime.
timo Posted December 30, 2019 Posted December 30, 2019 Random comments on your seemingly random questions: 1) Particle physics is indeed looking at debris to a very large extend. However, people are not looking for new objects in the debris. They look at the content and distribution of the debris and compare it with the predictions of the different mathematical models. 2) The reference to "statements about their encounters" does not refer to particle collisions (caveat: I am interpreting a single sentence out of context here - but modern particle physics did not exist during Einstein's lifetime, anyways). It refers to a key concept in relativity that comparing situations at different locations is tricky. It is not required that the objects in questions are elementary particles that collide. The famous spacefaring twins meeting each other after their space travel (or lack thereof) are would be typical situations that the statement refers to. 1
swansont Posted December 30, 2019 Posted December 30, 2019 E=mc^2 is a relativistic equation, so in that sense, GR has a lot to do with particle physics. The gravitational interactions, though, are probably not. Much smaller than the other interactions present, so likely much smaller than whatever nth order Feynman diagrams you are already ignoring because the math is too gnarly.
Markus Hanke Posted December 31, 2019 Posted December 31, 2019 17 hours ago, geordief said: (I am also learning that AE was a strong user of hallucinogenetic drugs and am quite astonished not to be aware of this until now https://vocal.media/futurism/11-things-you-may-not-know-about-albert-einstein Though I don’t feel strongly enough about the issue to motivate me into spending time to fact-check these claims, I am immediately suspicious of this article. Some of the substances mentioned here would - to the best of my limited knowledge - not even have been available during Einstein’s and Tesla’s lifetimes, or were not known back then to have hallucinogenic effects. I’m tempted to call BS on this, though I’m open to be told differently by someone more knowledgeable in matters of history.
geordief Posted December 31, 2019 Author Posted December 31, 2019 4 hours ago, Markus Hanke said: Though I don’t feel strongly enough about the issue to motivate me into spending time to fact-check these claims, I am immediately suspicious of this article. Some of the substances mentioned here would - to the best of my limited knowledge - not even have been available during Einstein’s and Tesla’s lifetimes, or were not known back then to have hallucinogenic effects. I’m tempted to call BS on this, though I’m open to be told differently by someone more knowledgeable in matters of history. Yes, a better search doesn't bring up anything at all to back that up. Had there been anything in it at all I would have found it very interesting ...but no news is no news.
MigL Posted December 31, 2019 Posted December 31, 2019 (edited) The best biography of A Eistein is written by A Pais ( Subtle is the Lord: the Science and the Life of A Einstein ), and, differing from most biographical works, includes a lot of theory and mathematics, since A Pais was himself a physicist. It makes no mention of A Einstein using/being fond of hallucinogenetic drugs. PS: Good to hear from you every once in a while, timo. Edited December 31, 2019 by MigL
Conjurer Posted January 4, 2020 Posted January 4, 2020 On 12/30/2019 at 8:50 AM, Mordred said: Which is why I always get a kick out of people discounting GR because it didn't predict dark matter or dark energy. It's not the function of GR to predict the particle model only how particles move in spacetime. I always get a kick out of how Mercury was the only celestial body that GR predicted more accurately than Newton's Theory of Gravitation in all of the Heavens.
Markus Hanke Posted January 4, 2020 Posted January 4, 2020 1 hour ago, Conjurer said: I always get a kick out of how Mercury was the only celestial body that GR predicted more accurately than Newton's Theory of Gravitation in all of the Heavens. This is not correct. The other planets are subject to relativistic perihelion precession as well, it’s just that the magnitude of the effect decreases as you move further away from the sun, so it is more difficult to detect. But the effect is still real even for the other planets, and Newtonian gravity fails to model it correctly.
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