On Monday, September 23, 2019 at 1:32:11 PM UTC-6, Brent wrote: > > > > On 9/23/2019 8:59 AM, Alan Grayson wrote: > > But Laplace was wrong in one very important respect. One can never > > know the exact position and momentum of any particle, let alone the > > entire universe. There are no perfect measurements! > > Laplace knew that. His point was that the future (and the past) were > completely determined by the present state of the world. Even though we > can't measure it perfectly, Laplace assumed that the variables like > position and momentum had definite values. That's what is > fundamentally different about quantum mechanics, they don't have > definite values. > > > Further, the situation is further aggravated by the Uncertainty > > Principle. In sum, using classical mechanics the future is NOT > > determined by its present, imprecise configuration. > > The uncertainty principle is part of QM not CM.
Yes, and I didn't indicate otherwise. AG Just because you can't > measure it precisely, doesn't mean that the present configuration is not > precise; it means that we are ignorant of the precise values. This was > Einstein's idea, that QM was incomplete and its randomness was just an > expression of our ignorance, as in CM. > That's not the mainstream view today IIUC. It's that position and momentum as simultaneous values don't exist, not that we can't measure them precisely. AG > > > Not only is Laplace mistaken, but Carroll as well, who should know > > better. AG > > Neither Laplace nor Carroll is mistaken. > Carroll intentionally misstated Laplace's position in an attempt to make his reasoning plausible. So IMO he's not only wrong about MW, but dishonest as well. AG > > Brent > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/5150881e-6894-4843-a7d3-8f720de5343a%40googlegroups.com.
