On Friday, December 30, 2022 at 10:13:41 AM UTC-6 spudb...@aol.com wrote:
> Hence, the plausibility of the causality of Smolin's Autodidactic
> Universe.
> The Laws of the Universe Are Changing | RealClearScience
> <https://www.realclearscience.com/2022/07/09/the_laws_of_the_universe_are_changing_841586.html>
>
> Slum-dunk? No, there is only more research to be funded to search for what
> can be detected.
>
> For this peasant? A great working theory.
>
>
>From what I know of observations and measurements there has been no
recorded evidence of the laws of physics changing.
LC
>
> -----Original Message-----
> From: Lawrence Crowell <goldenfield...@gmail.com>
> To: Everything List <everyth...@googlegroups.com>
> Sent: Fri, Dec 30, 2022 10:04 am
> Subject: Re: Physics? Ok Astronomers view 2 distant Water Worlds so
> following the physics I ask..
>
> On Wednesday, December 28, 2022 at 11:41:36 PM UTC-6 Bruce wrote:
>
> On Thu, Dec 29, 2022 at 4:34 PM Brent Meeker <meeke...@gmail.com> wrote:
>
> On 12/28/2022 9:01 PM, Bruce Kellett wrote:
>
> On Thu, Dec 29, 2022 at 3:29 PM Brent Meeker <meeke...@gmail.com> wrote:
>
> Of course one reason there are "laws of physics" is what my late friend
> Vic Stenger called Point Of View Invariance. This was his generalization
> of Emmy Noether's theorem that showed every symmetry implied a conservation
> law.
>
>
> That is not strictly true. It is only continuous symmetries of the
> Lagrangian that imply conservation laws -- not all symmetries. For example,
> the symmetries of a square under rotation and reflection do not generate
> any conservation laws. Neither do discrete symmetries like parity and
> charge conjugation.
>
> So momentum is conserved because we want any law of physics to be
> invariant under translation of a different location. Energy is conserved
> because we want the laws of physics to be the same at different times, etc.
>
>
> It is not what we want, it is what we find. We find that nature is
> invariant under these continuous transformations, so we build those
> symmetries into our laws.
>
>
> Vic called in POVI because he wanted to extend it to transformations in
> abstract spaces, e.g. gauge invariance. Of course the invariance depends
> on the "point of view" in a sense. Things didn't look at all space
> translation invariant to Aristotle. Galileo said ignore that your ship is
> moving along the shore, just look at the dynamics in the cabin. So we
> discovered these symmetries by learning what ignore as well as what to
> measure.
>
>
> The real point is that the laws are discovered, not imposed. The fact that
> continuous symmetries correspond to conservation laws was discovered only
> very much later. Most of the history of physics is about discovering what
> works -- what the laws might be. POVI was thought of only very late in the
> game, and is not a fundamental insight.
>
> Bruce
>
>
> This begins to look a bit similar to the debate over whether mathematics
> is objectively real or something invented. Emmy Noether gave consideration
> to that boundary term we usually discard when deriving the Euler-Lagrange
> formula to show that a symmetry was involved with this term. This symmetry
> and that this boundary term is zero meant a conservation law. A law of
> physics considered as such is something associated with covariant and
> invariant properties of space, spacetime or an abstract space under some
> set of transformations. Is this principle, a law of laws should we say,
> something that is discovered or is some objective aspect of a mathematical
> reality?
>
> The type D, II, III and N solutions, black holes = D and gravitational
> waves = N, are vacuum solutions with the Weyl tensor C_{abcd} that wholly
> determines the curvature. The Weyl curvature is an operator on Killing
> vectors, such that Killing vectors are eigenvalued with the Weyl curvature
> C_{abcd}K^bK^d = λK_aK_c. The type N solutions have Killing vectors that
> have zero eigenvalue C_{abcd}K^d = 0. Type III spacetimes have λ = 0 and
> type II and D have nontrivial eigenvalues that are unequal for C_{abcd} and
> *C_{abcd}, for * the Hodge dual with C_{abcd}K^bK^d = λK_aK_c and
> *C_{abcd}K^bK^d = λ’K_aK_c for λ ≠ λ’ and λλ ≠ 0. These Killing vectors
> define symmetries and thus conservation laws. A timelike Killing vector
> defines conservation of energy, a spacelike Killing vector defines
> conservation of momentum, and a Killing bi-vector or one derived from such
> defines conservation of angular momentum. That is a total of 1 + 3 + 6 = 10
> Killing vectors. These eigenvalued equations should make one think of the
> Schrodinger equation. Indeed for a timelike Killing vector K_t =
> √(g_{tt})∂_t so that this gives a general wave equation HΨ[g] =
> iK_t∂Ψ[g]/∂t, which for g_{tt} = 1 is the Schrodinger equation. The ADM
> approach to general relativity give NH = 0 and the Wheeler-deWitt equation
> HΨ[g] = 0. General relativity does not automatically define conservation
> laws. Conservation laws only occur with certain symmetries of spacetime.
> This often occurs where there is an ADM mass defined by an asymptotic
> condition of flatness or some other spacetime with constant curvature at a
> distance.
>
> Conservation laws appear as asymptotic or boundary terms. The AdS/CFT
> correspondence of Maldacena shows that a nonlocal quantum gravity theory
> corresponds to a local conformal field theory on the conformal boundary of
> the anti-de Sitter spacetime. The anti-de Sitter (AdS) spacetime has
> constant negative curvature. This is a negative vacuum energy, where this
> has some correspondence with string theory, such as the type I string
> theory has a negative energy vacuum and its first excited state is a
> negative energy state. The AdS_4 has a correspondence with black hole
> physics. The AdS spacetime is not the spacetime of the observable universe.
> It is though in line with the theory of Emmy Noether, also work by
> Hurzebruch, and even the old Gauss-Bonnet theory.
>
> Physical spacetime is more similar to de Sitter spacetime, and is the
> Friedmann-Lemaitre-Robertson-Walker spacetime with positive energy. This
> means curvature is positive, which involves how space is embedded in
> spacetime, and this does not have conservation laws. If that space is a
> sphere S^3 the constant vacuum energy on this space grows with the
> evolution of this space and volume growth. This is one reason that people
> tend to prefer the flat space model, where vacuum energy is net "infinity"
> and remains so. However, there is nothing to prevent vacuum energy density
> from changing. The phantom energy model leading to a big rip of the cosmos
> is possible, and the curious discrepancy between CMB and SNII data, with
> the Hubble constant H = 70km/sec-Mpc and H = 74km/sec-Mpc respectively,
> appears to resist analysis meant to show it is zero. If the phantom energy
> model should be realized then conservation of energy, even with an infinite
> flat space, is gone.
>
> The expansion of the universe also means we will not be able to observe
> much physics that could be called “pre-cosmic,” or the quantum gravitation
> of the pre-inflationary universe. Because of inflation and this 60-efolds
> of expansion, expansion by ~ 10^{29}, a Planck scale region was expanded
> from 10^{-33}cm to 10^{-4} cm. Since inflation began at 10^{30} sec in the
> early universe, any Planck scale fluctuation involved with the generation
> of the universe would have been 10^{-23}cm, and was expanded to 10^6 cm ---
> beyond the scale of the then observable universe ~ 10cm. After inflation
> the observable universe with a scale of ~ 10cm an possible Planck scale
> process was stretched by more normal expansion to 10^{10} light years, and
> might appear as some order anisotropy in the CMB. Using blackbody physics,
> these quanta would have been a tiny aspect of the early universe. These
> would be very difficult to find in the CMB. Beyond that, we cannot observe
> anything. Any pre-cosmic physics emerged from something smaller than the
> Planck scale and is expanded beyond any measurable scale on the CMB.
>
> John Wheeler said that the ultimate law of physics is there is no law. We
> may then have something similar to this, where what we call the laws of
> physics are just local emergent pattern in the observable universe. At
> large the universe may simply have no conservation laws and ultimate there
> are globally no physical laws.
> LC
>
>
>
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