display all the ideas for this combination of texts
9 ideas
| 20636 | Newton is a special case of Einstein's general theory, with an infinite speed of light [Einstein, by Close] |
| Full Idea: Einstein's general relativity included Newton's theory as a special case: Newton's theory corresponds to the speed of light being infinite relative to the speed of the interacting bodies. | |
| From: report of Albert Einstein (works [1915]) by Frank Close - Theories of Everything 5 'Gravity' | |
| A reaction: So Newton's theory was NOT wrong, but he made the false assumption that the speed of light was infinite. |
| 21230 | The theory is 'special' because it sticks to observers moving straight, at constant speeds [Einstein, by Farmelo] |
| Full Idea: Einstein's first theory is 'special' because it only deals with observers who move in a straight line at constant speeds with respect to one another. | |
| From: report of Albert Einstein (works [1915]) by Graham Farmelo - The Strangest Man 03 | |
| A reaction: Most theories of this period seem to have focused on the simplest cases, for obvious reasons. |
| 21231 | Assume the speed of light is constant for all observers, and the laws of physics are the same [Einstein, by Farmelo] |
| Full Idea: Einstein assumed that when each observer measures the speed of light in a vacuum, they find the same value, regardless of their speed; and that measurements will lead to agreement on the laws of physics. | |
| From: report of Albert Einstein (works [1915]) by Graham Farmelo - The Strangest Man 03 | |
| A reaction: So are the laws of physics constant for all observers, irrespective of their speed? |
| 20634 | General Relativity says there is no absolute force or acceleration [Einstein, by Close] |
| Full Idea: Einstein's General Theory arose from the idea that there is no absolute measure of force and acceleration. | |
| From: report of Albert Einstein (works [1915]) by Frank Close - Theories of Everything 5 'Gravity' | |
| A reaction: If absolutely everything is only true relative to something else you wonder what the point of measuring anything is. How big can a 'frame of reference' or 'inertial frame' be. Is the multiverse a frame of reference? |
| 20648 | Mass is a measure of energy content [Einstein] |
| Full Idea: The mass of a body is the measure of its energy content. | |
| From: Albert Einstein (works [1915]), quoted by Peter Watson - Convergence 04 'Intro' | |
| A reaction: If I knew what energy was, this would be very illuminating. This idea is e=mc^2 in words. We now have the Higgs field to consider when trying to understand mass. |
| 21232 | Space-time arises from the connection between measurements of space and of time [Einstein, by Farmelo] |
| Full Idea: Einstein noted that the measurements of space and time are not independent but inextricably linked, leading to the idea of unified space-time (introduced by his former teacher Minkowski). | |
| From: report of Albert Einstein (works [1915]) by Graham Farmelo - The Strangest Man 03 | |
| A reaction: Notice the instrumentalist assumptions behind this. |
| 20819 | The past and the future subsist, but only the present exists [Chrysippus, by Plutarch] |
| Full Idea: When he wished to be subtle, Chrysippus wrote that the past part of time and the future part do not exist but subsist, and only the present exists. | |
| From: report of Chrysippus (fragments/reports [c.240 BCE]) by Plutarch - On Common Conceptions 1081f | |
| A reaction: [from lost On Void] I think I prefer the ontology of Idea 20818. Idea 20819 does not offer an epistemology. Is the present substantial enough to be known? The word 'subsist' is an ontological evasion (even though Russell briefly relied on it). |
| 20818 | The present does not exist, so our immediate experience is actually part past and part future [Chrysippus, by Plutarch] |
| Full Idea: Stoics do not allow a minimal time to exist, and do not want to have a partless 'now'; so what one thinks one has grasped as present is in part future and in part past. | |
| From: report of Chrysippus (fragments/reports [c.240 BCE]) by Plutarch - On Common Conceptions 1081c | |
| A reaction: [from lost On Parts Bk3-5] I agree with the ontology here, but I take our grasp of the present to be very short-term memory of the past. I ignore special relativity. Chrysippus expressed two views about this; in the other one he was a Presentist. |
| 20821 | Time is continous and infinitely divisible, so there cannot be a wholly present time [Chrysippus, by Stobaeus] |
| Full Idea: Chrysippus says most clearly that no time is wholly present; for since the divisibility of continuous things is infinite, time as a whole is also subject to infinite divisibility by this method of division. | |
| From: report of Chrysippus (fragments/reports [c.240 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: But what is his reason for thinking that time is a continuous thing? There is a minimum time in quantum mechanics (the Planck Time), but do these quantum intervals overlap? Compare Idea 20819. |