Frank Arntzenius - Are There Really Instantaneous Velocities?

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Күн бұрын

Пікірлер: 9

@CjqNslXUcM 7 ай бұрын

It seems to me that, definitionally, you need instantaneous velocities for a markovian world with instants to exist. An instant without velocities would have more than one possible past and future. I'm entirely comfortable with the idea of using chunks of time with length epsilon instead of actual infinitesimals (instants) existing. Actual points cause a lot of headaches, such as the banach-tarski paradox. Thank you for the video!

@Abren_ 7 ай бұрын

Hi - really interesting video, thanks for sharing your insight outside of your academic institution. Intuitively, speaking of instantaneous velocity feels paradoxical to me.

@MELUTONIN 3 ай бұрын

I think it's easier to start with momentum then and use that to define velocity. Conversation of momentum follows from the laws of physics being constant over spacetime (Noether's theorem) and momentum is already treated like an intrensic property in physics.

@jamesb46 5 ай бұрын

The principle that if an object does not have a property at every instant of an interval, then on the interval in does have the property is not the whole story. A better statement would be: if it is possible at every instant for an object to have a property, then if for every instant it does not have the property, then on any interval that contains only those instant, it lacks the property. Otherwise it is akin to the fallacy of composition.

@tesafilm8447 7 ай бұрын

Really interesting topic! Have you also been thinking about making a video on (contradictory) accounts of change?:)

@VictorGijsbers 7 ай бұрын

I'm not exactly planning it, but it might certainly happen. I believe one of my colleagues, Martin Lipman, has written about that in his work on fragmentalism; could be a good way to approach it.