On 16 January 2014 19:20, meekerdb <meeke...@verizon.net> wrote: > On 1/15/2014 7:44 PM, Stephen Paul King wrote: > > Dear LizR, > > But stop and think of the implications of what even Bruno is saying. > *Space > is completely a construction of our minds.* *There is no 3,1 dimensional > Riemannian manifold out there*. We measure events and our minds put those > together into tableaux that we communicate about and agree on, because our > languages, like formal logical system, force the results to obey a set of > implied rules. We formulate explanations, formulate models and look for > rules that the models might obey. Hopefully we can make predictions and > measure something... > > > Sure we create models like spacetime - BUT we can agree on them and they > are successful models both in prediction and in explanations leading to > other models. You write *like this a new discovery.* The set of rules > isn't implied, it's quite explicit: The model must be the same for > everybody in every circumstance. Physics is intended to apply everywhere. > That's why momentum and energy are conserved. These models are our best > guess about what's out there. So it makes no more sense to say *"There is > no 3,1 dimensional Riemannian manifold out there" *than to say "There is > no computer monitor in front of me." or "I'm a brain in a vat." or "There > is no refrigerator in my kitchen." >
If I remember correctly, momentum is conserved because space has no preferred direction and energy is conserved because there is no preferred time. An insight we owe to one of my heroes, the wonderful Emmy Noether, if I'm not mistaken. -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.