Matthew SandsBesprekingen
Auteur van The Feynman Lectures on Physics, Vol. 1: Mainly Mechanics, Radiation, and Heat
Besprekingen
En berømt forelæsningsrække blev omformet til disse noter.
Jeg kan godt lide forordet, hvor baggrunden for forelæsningerne er ridset op. Appendix er to kapitler fra Volume II som bruges meget i dette Volume III. Så det er meget behageligt at de lige er taget med som appendix.
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jculkin | 4 andere besprekingen | Feb 1, 2016 |
jculkin | 4 andere besprekingen | Feb 1, 2016 | Onze site gebruikt cookies om diensten te leveren, prestaties te verbeteren, voor analyse en (indien je niet ingelogd bent) voor advertenties. Door LibraryThing te gebruiken erken je dat je onze Servicevoorwaarden en Privacybeleid gelezen en begrepen hebt. Je gebruik van de site en diensten is onderhevig aan dit beleid en deze voorwaarden.
Feynman is eminently quotable. A sampling:
[on actually measuring positions of planets and how they moved]
This was a tremendous idea—that to find something out, it is better to perform some careful experiments than to carry on deep philosophical arguments.
{This is the idea. Philosphers tend to ask questions with no answers (although some of them think they come up with answers). Science looks for answers to real questions.}
[Universal gravitation]
This phenomenon showed that light does not travel instantaneously, and furnished the first estimate of the speed of light. This was done in 1676.
[on precision of definition]
Perhaps you say, “That’s a terrible thing—I learned that in science we have to define everything precisely.” We cannot define anything precisely! If we attempt to, we get into that paralysis of thought that comes to philosophers, who sit opposite each other, one saying to the other, “You don’t know what you are talking about!” The second one says, “What do you mean by know? What do you mean by talking? What do you mean by you?,” and so on.
{Love it!}
[more on philosophers]
...what is an object? Philosophers are always saying, “Well, just take a chair for example.” The moment they say that, you know that they do not know what they are talking about any more. What is a chair? Well, a chair is a certain thing over there … certain?, how certain? ”
{45 years I've been saying they don't know what they are talking about...}
[on relativity]
Poincaré made the following statement of the principle of relativity: “According to the principle of relativity, the laws of physical phenomena must be the same for a fixed observer as for an observer who has a uniform motion of translation relative to him, so that we have not, nor can we possibly have, any means of discerning whether or not we are carried along in such a motion.”
[on cocktail party philosophers]
When this idea descended upon the world, it caused a great stir among philosophers, particularly the “cocktail-party philosophers,” who say, “Oh, it is very simple: Einstein’s theory says all is relative!” In fact, a surprisingly large number of philosophers, not only those found at cocktail parties (but rather than embarrass them, we shall just call them “cocktail-party philosophers”), will say, “That all is relative is a consequence of Einstein, and it has profound influences on our ideas.””
[on notation]
We could, of course, use any notation we want; do not laugh at notations; invent them, they are powerful. In fact, mathematics is, to a large extent, invention of better notations.