On 3 March 2014 13:39, meekerdb <[email protected]> wrote: > On 3/2/2014 3:46 PM, LizR wrote: > > 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). > > > Of course different forms of energy were identified - but by showing > something not previously accounted for could be called 'energy' and thereby > achieve conservation. I don't think the general conservation of energy was > considered a firm principle until the mid 1800's and its violation was > seriously entertained in the case of beta decay. But the idea that the > "laws of physics" should not depend on time or place goes back much further > and had broader historical support; not just empirical but also > metaphysical. >
But only because observations indicate that is how the universe works. (Actually we do have a theory that references a specific time - the Big Bang.- but I know what you mean.) Notice how outrageous Edgar's p-time appears, and he just wants a universal > clock. How would it sound to put forth a theory that reference a specific > time? No one would accept it as fundamental. > However, Edgar's p-time would have seemed perfectly plausible to a Newtonian physicist. > Also, some processes *do *violate symmetries, and these have been duly > detected, and scientists were duly surprised. > > Sure, SR violate Galilean symmetry, CPT isn't even a continuous symmetry > and so doesn't fall under Noether's theorem. I don't claim it's an > absolute requirement (notice I said "desiderata") but it's surprising how > much you can get out of symmetry principles. Did you read Stenger's > essay? My main point though was to look a little askance at Tegmark, and > others, idea that if we *just* get the right math, or the most elegant > theory, then we'll know what's really real. I don't think they pay enough > attention to the fact that we make up the laws of physics. > I would dispute your use of "just" here! Obviously they are hopeful that we will eventually uncover "the truth", even if we can never prove we've done so, but I'm not sure that is *necessarily* unrealistic, even if it proves to be impossible in practice. I find Tegmark's metaphysical speculations interesting, because he is at least trying to get his head around the big questions, like why is there something rather than nothing? In fact his is the *only* satisfactory answer to that question I've ever come across, which is quite an achievement, imho, even if it proves to be wrong. -- 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.
