On 3 March 2014 11:54, meekerdb <[email protected]> wrote: > On 3/2/2014 2:38 PM, LizR wrote: > > On 3 March 2014 08:33, meekerdb <[email protected]> wrote: > >> >> I don't think Tegmark appreciates how much the "laws of physics" depend >> on our demands that the "laws" be invariant, e.g. conservation of energy is >> a consequence of requiring the lagrangian to be time-translation invariant. >> > > That isn't a demand, it's an observation. (Made by Emmy Noether, IIRC.) > > Noether observed the connection between continuous symmetry in a > lagrangian and the existence of a corresponding conserved quantity. But > that a lagrangain (or theory in any form) have that character is a > "demand"; or at least a strong desiderata. Remember how the neutrino was > discovered. If some process seemed to not conserve energy, we'd just look > for something new we could count as the energy difference. >
I don't want to nitpick here, but that sounds like a highly disingenuous comment to come from someone who knows a lot about physics (either you or Vic Stenger). IMHO it makes perfect sense to expect an unexplained phenomenon to obey conservation laws, given their success to date. That is, given that everything in the universe that had been studied over the previous 300 years or so appeared to obey these principles, why would they immediately assume that they wouldn't apply to a new discovery? And as it turned out, they were right. Neutrinos have observational consequences above and beyond being a mere "accounting process" in beta decay, or whatever it was, such as being directly detected, as well as having strong theoretical support (e.g. in how the sun operates and how supernovas explode). Also, some processes *do *violate symmetries, and these have been duly detected, and scientists were duly surprised. I'm kind of surprised myself to see you coming out with what seems like a postmodernist take on how scientists operate. -- 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 post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
