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3 ideas
6807 | In Newton mass is conserved, but in Einstein it can convert into energy [Bird] |
Full Idea: According to Newton mass is conserved, while in Einstein's theory mass is not conserved but can be converted into and from energy. | |
From: Alexander Bird (Philosophy of Science [1998]) | |
A reaction: Perhaps this is the most fundamental difference between the theories. It certainly suggests that 'mass' was a conventional concept rather than a natural one. Maybe the relative notion of 'weight' is more natural than 'mass'. |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |
3985 | Biology is a type of engineering, not a search for laws of nature [Dennett] |
Full Idea: Biology is not a science like physics, in which one should strive to find 'laws of nature', but a species of engineering. | |
From: Daniel C. Dennett (Daniel Dennett on himself [1994], p.239) | |
A reaction: Yes. This is also true of chemistry, which has always struck me as minitiarised car mechanics. |