12 ideas
4577 | There is no necessity higher than natural necessity, and that is just regularity [Quine] |
Full Idea: In principle I see no higher or more austere necessity than natural necessity; and in natural necessity, or our attribution of it, I see only Hume's regularities | |
From: Willard Quine (Necessary Truth [1963], p.76) | |
A reaction: Presumably this allows logical necessity as a 'lower' necessity, but denies 'metaphysical' necessity, in line with Hume and other tough empiricists. Personally I adore metaphysical necessities, but they are a bit hard to establish conclusively. |
7621 | Special relativity, unlike general relativity, was operationalist in spirit [Putnam on Einstein] |
Full Idea: Einstein's interpretation of special relativity was operationalist in spirit (in marked contrast to the interpretation he gave to general relativity). | |
From: comment on Albert Einstein (works [1915]) by Hilary Putnam - Reason, Truth and History Ch.5 | |
A reaction: The late twentieth century was polluted with daft relativism, and I hold Einstein partly responsible, suspecting that he was a bad philosopher. The later development of Einstein's view noted here is interesting. |
19216 | Propositions (such as 'that dog is barking') only exist if their items exist [Williamson] |
Full Idea: A proposition about an item exists only if that item exists... how could something be the proposition that that dog is barking in circumstances in which that dog does not exist? | |
From: Timothy Williamson (Necessary Existents [2002], p.240), quoted by Trenton Merricks - Propositions | |
A reaction: This is a view of propositions I can't make sense of. If I'm under an illusion that there is a dog barking nearby, when there isn't one, can I not say 'that dog is barking'? If I haven't expressed a proposition, what have I done? |
22955 | Einstein took causation to be the bedrock of physics [Einstein, by Coveney/Highfield] |
Full Idea: It is difficult to overplay Einstein's commitment to the concept of causality as the bedrock of physics. | |
From: report of Albert Einstein (works [1915]) by P Coveney / R Highfield - The Arrow of Time 3 'problem' | |
A reaction: I normally avoid arguments from authority, but this carries a bit of weight (e.g. when Russell tries to oppose it). What happens to Einstein's theories if you remove causation from them? |
20638 | General relativity assumes laws of nature are the same in all frames of reference [Einstein, by Close] |
Full Idea: Einstein came to general relativity from the principles that the laws of nature are the same in all frames of reference. | |
From: report of Albert Einstein (works [1915]) by Frank Close - Theories of Everything 5 'Cosmological' | |
A reaction: I wish physicists would tell us a bit more about the ontological status of the 'laws of nature'. Presumably they are not supernatural, so there is an aspect of nature which is constant in all frames of reference. Explanation please. |
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. |
7626 | I do not believe in a personal God [Einstein] |
Full Idea: I do not believe in a personal God and I have never denied this but have expressed it clearly. | |
From: Albert Einstein (works [1915]), quoted by Richard Dawkins - The God Delusion Ch.1.15 | |
A reaction: This is an important corrective to those who claim Einstein as religious, on the basis of remarks about God not playing dice etc. See the whole of Dawkins's chapter on Einstein for full discussion. |