On Thu, Dec 20, 2018 at 7:05 PM Bruce Kellett <bhkellet...@gmail.com> wrote:
> On Fri, Dec 21, 2018 at 11:45 AM Jason Resch <jasonre...@gmail.com> wrote: > >> On Thu, Dec 20, 2018 at 3:26 PM Bruce Kellett <bhkellet...@gmail.com> >> wrote: >> >>> On Fri, Dec 21, 2018 at 2:35 AM Jason Resch <jasonre...@gmail.com> >>> wrote: >>> >>>> On Thu, Dec 20, 2018 at 5:01 AM Bruce Kellett <bhkellet...@gmail.com> >>>> wrote: >>>> >>>>> On Thu, Dec 20, 2018 at 8:18 PM Jason Resch <jasonre...@gmail.com> >>>>> wrote: >>>>> >>>>>> On Wed, Dec 19, 2018 at 4:34 PM Bruce Kellett <bhkellet...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> On Thu, Dec 20, 2018 at 4:21 AM Bruno Marchal <marc...@ulb.ac.be> >>>>>>> wrote: >>>>>>> >>>>>>>> On 19 Dec 2018, at 12:59, Bruce Kellett <bhkellet...@gmail.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>> Dynamics is the study of matter in motion. There are no clocks in >>>>>>>> arithmetic. >>>>>>>> >>>>>>>> Of course there is clock. The successor function implements it out >>>>>>>> of time and space. >>>>>>>> >>>>>>> >>>>>>> The fact that you can use one ordered sequence to index another >>>>>>> ordered sequence does not constitute a clock. >>>>>>> >>>>>>> Nothing exists out of time and space, not even time and space >>>>>>> themselves. >>>>>>> >>>>>> >>>>>> Accordingly, you must reject: >>>>>> >>>>>> - Membranes >>>>>> - String theory landscape >>>>>> - Eternal inflation >>>>>> - The inside of black holes (yet another observer-dependent >>>>>> phenomenon) >>>>>> - Other universes with different physics (it's amazing that our >>>>>> universe allows for life, assuming it's the only universe that exists) >>>>>> >>>>>> All of these ideas have at least some motivation/support. Why reject >>>>>> them out of hand? >>>>>> >>>>> >>>>> This is a very mixed list! Some of these have no evidential support, >>>>> some are mere speculation, and other universes with different physics is a >>>>> long stretch, not at all in accordance with present knowledge. I do not >>>>> reject all these possibilities, but we do need more data on some of them. >>>>> None of them exist outside of space-time, however. >>>>> >>>> >>>> What do you think about the apparent fine-tuning of the universe? e.g. >>>> https://www.amazon.com/Just-Six-Numbers-Forces-Universe-ebook/dp/B00CW0H6JY >>>> >>>> Isn't this a very strong statistical argument that other universes with >>>> different physical laws must exist? >>>> >>> >>> No. there is no evidence for that at all. Why should the constants of >>> nature be a random selection from some distribution? >>> >>> >> 1. It is a prediction of eternal inflation and string theory. >> > > String theory and its "landscape" are very speculative, and unlikely to > have any relation to the real world -- there is no evidence that string > theory is even a coherent theory! Eternal inflation, although popular, is > only one possibility for inflation, and even inflationary theory itself is > not well-established science. > > I agree they are speculative, but they are on the side many many universes. Meanwhile there is no evidence for "the only universe that exists is the one I can see". > 2. There is no known principal that prohibits other systems ruled by >> different laws. >> > > The idea that everything that is not forbidden must exist is a silly > metaphysical notion. > > That's not the position I was advocating, though I think that notion is less silly than the idea that we should expect to be in a position to see everything that exists. > 3. The digits of the dimensionless constants at significance levels not >> important to life appear to be randomly distributed >> > > Appearances can be deceptive -- vide flat earth. > > What do you think determines the dimensionless constants? > 4. It is highly surprising that the dimensionless constants hold the >> values they do as if they were even slightly different, the universe would >> be too simple for any life to exist >> > > How do you know that? > > It is difficult to create systems that develop spontaneous complexity, as any programmer could tell you. That our universe is such a system is surprising, given that most systems do not yield spontaneous complexity. > Look, the Bayesian prior for any argument about the nature of the universe > is that we exist. So there is nothing in the least surprising about the > fact that the universe we observe is compatible with our existence. > Anything else is just idle speculation. > But that's not the correct prior to use. Your assumption is that one and only one universe exists. Starting from that assumption you must then ask what is the probability that life will exist in that one and only one universe. Given that the probability is low, would suggest the initial assumption is wrong. Of the 26 dimensionless constants, lets say each one had a 50/50 chance of leading to catastrophe (no life) if in an invalid range. Then the probability that all constants would be in the correct range is (1/2)^26 = 1 in 67 million. We should then be (1 - (1/2)^26) sure that the universe we can see is not the only one. > > >> Why do you believe there is only one inevitable possibility for the laws >> of physics? I've never heard any justification for that idea. >> > > Why do you think I believe that? > You seemed to reject the idea of other possible physical systems ruled by different laws, and that the dimensionless constants are not from some random distribution. > One idea about the end-point of physics is that there is a TOE that will > explain everything -- predict the values of all constants and so on, maybe > even specify a lot of the boundary conditions. Why do you believe that such > a TOE is not possible? > I realize that is the dream of many physicists, but science has provided no justification for the success that initiative, and substantial evidence that such an initiative is doomed to fail (e.g., all the evidence of landscapes). Jason -- 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. 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