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Path: ...!Xl.tags.giganews.com!local-3.nntp.ord.giganews.com!news.giganews.com.POSTED!not-for-mail NNTP-Posting-Date: Sun, 17 Nov 2024 18:05:11 +0000 Subject: Re: Is Curved Space An Improvement Over The Use of the Concept of Forces? Newsgroups: sci.physics.relativity References: <1faa69846c0c2c810b1d0e04143399cd@www.novabbs.com> <139e5148ed64d73023c6fe30c51b957b@www.novabbs.com> <EGWdnQr_YarasKf6nZ2dnZfqnPudnZ2d@giganews.com> From: Ross Finlayson <ross.a.finlayson@gmail.com> Date: Sun, 17 Nov 2024 10:05:08 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <EGWdnQr_YarasKf6nZ2dnZfqnPudnZ2d@giganews.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Message-ID: <UAidncN-6YPFraf6nZ2dnZfqnPidnZ2d@giganews.com> Lines: 223 X-Usenet-Provider: http://www.giganews.com X-Trace: sv3-tnlF/MMdQFlAT5wyBzQoYlEgzMrfcXdh61UTwtjeLxUpDK9MwNP+U15taeLIYXTlMTT0cTTvwkNGmlQ!ox532r5tOEPHcq1bYd2AEk/ch8ClzkghoA4Y/ZAfK7bxejNlw1bQnxs6Fma4KJACoOhC9wTAMA== X-Complaints-To: abuse@giganews.com X-DMCA-Notifications: http://www.giganews.com/info/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 10704 On 11/17/2024 09:52 AM, Ross Finlayson wrote: > On 11/16/2024 11:50 PM, ProkaryoticCaspaseHomolog wrote: >> On Sat, 16 Nov 2024 23:48:09 +0000, LaurenceClarkCrossen wrote: >> >>> Is Curved Space An Improvement Over The Use of the Concept of Forces? >> >> [SNIP] >> >> The following text has been edited very little from the version that >> I added to Wikipedia in April 2018. >> https://en.wikipedia.org/wiki/Spacetime#Is_spacetime_really_curved? >> >> Is spacetime really curved? >> >> In Poincaré's conventionalist views, the essential criteria according >> to which one should select a Euclidean versus non-Euclidean geometry >> would be economy and simplicity. A realist would say that Einstein >> discovered spacetime to be non-Euclidean. A conventionalist would say >> that Einstein merely found it more convenient to use non-Euclidean >> geometry. The conventionalist would maintain that Einstein's analysis >> said nothing about what the geometry of spacetime really is. >> >> Such being said, >> 1) Is it possible to represent general relativity in terms of flat >> spacetime? >> 2) Are there any situations where a flat spacetime interpretation >> of general relativity may be more convenient than the usual >> curved spacetime interpretation? >> >> In response to the first question, a number of authors including >> Deser, Grishchuk, Rosen, Weinberg, etc. have provided various >> formulations of gravitation as a field in a flat manifold. Those >> theories are variously called "bimetric gravity", the "field- >> theoretical approach to general relativity", and so forth. Kip >> Thorne has provided a popular review of these theories. >> >> The flat spacetime paradigm posits that matter creates a gravitational >> field that causes rulers to shrink when they are turned from >> circumferential orientation to radial, and that causes the ticking >> rates of clocks to dilate. The flat spacetime paradigm is fully >> equivalent to the curved spacetime paradigm in that they both >> represent the same physical phenomena. However, their mathematical >> formulations are entirely different. Working physicists routinely >> switch between using curved and flat spacetime techniques depending on >> the requirements of the problem. The flat spacetime paradigm is >> convenient when performing approximate calculations in weak fields. >> Hence, flat spacetime techniques tend be used when solving >> gravitational wave problems, while curved spacetime techniques tend be >> used in the analysis of black holes. > > The space-time curvature is a mere mental model > to effect to reflect a milieu of "gravity" in a theory > with massy bodies and a universal law of gravitation. > > So, all it is, is, a "geodesy", that has all these level or > plane curves according to integral analysis, that > accordingly, a "test-mass", which is an arbitrarily > small amount of mass, that the test-mass in this > field of potentials, follows in the geodesy, its > "world-line", that is merely the gradient descent, > that the test-mass follows its world-line. > > Then, the theory has a "mass-energy equivalency" > combined with an L-principle, and indeed two L > principles, that "relativistic mass" reflects inertially > resistance to acceleration, yet as well, tendency > to fall faster in the world-line. > > So, there's an L-principle that light's speed is a > constant, and that light, though mass-less, > behaves as a test-mass in the geodesy, that's > what it's said to do. Then also there's that > the energy according to arbitrarily referenced > velocity, has that this "c" is effectively infinity > in this theory, that to reach it requires infinite > energy because a given massy body accumulates > or radiates any, "relativistic mass". > > Then, in this "potential well", of gravity, this geodesy, > it's always evaluated instantaneously with regards > to all massy-bodies everywhere all the time constantly. > This is usually left out yet otherwise has that nothing > would ever happen or move. > > So, most usually it's considered with regards to > the gravity well of Earth the terrestrial, that > humans are so small as to be like test-masses, > and any "curvature" of space-time, is no different > than Newton's universal law of gravitation, > according to Earth's mass and Galileo's what > results the constancy there, of gravity, is yet > only because the 2-body system has it so negligeable, > what's otherwise the mutually proportional product, > inverse the distance square. > > > Then it results that the gradient descent the > world-line, is merely "down", that it's "down" > in the gravity well, that of course there's an > implicit tendency of massy bodies to accelerate > according to gradient descent and a tautochrone, > that's also usually left out as it was already given > back to the universal law of gravitation, and > Galileo's simplifications of what's otherwise > inter-actions. > > "Down, Einstein?" "Yeah, straight down." > > > So, the frames are the containers as it were > of mass, and relativistic mass, and live in a space. > > Thusly you can notice that a variety of things > are left under-defined, for example how a > photon can be mass-less and travel at c, > versus being a test-mass and follow a world-line. > > > Similarly there's that a given frame _has space in it_, > that a frame has spaces in it and a space has frames > in it, space-frames and frame-spaces, that usually > the theory is nested frames, and space is just a > great outside local "flat" section, whatever is > the nearest center gravitationally. > > It doesn't have to be that way, and in the same theory, > that there are implicits and "un-stated" assumptions > in the theory, that are always givens, while yet it's > always world-lines the geodesy and a flat locality > where things go straight down, as down the ramp, > the ramp, of the gradient descent, of "space-time", > keeping up the tauto-chronous like that, as after > a most sort of machine in operation, the inclined > plane, or ramp. > > > Then, in a sense, it's always _of_ and "flat space-time", > what's down, and always in a "flat space-time", > what's around. > > Then, as with regards to what defines the ramp > the gradient descent, it's classical universal law > of gravitation what makes a geodesy, considering > relativistic mass, and, classical motion down a ramp > in classical linear downward gravitation, about > all of classical mechanics. > > > So, these are as well under-defined, and also, > classical mechanics is even under-defined, as > with regards to whatever's more than a > space-time where everything orbits or falls, > apart from each other, and nothing ever meets. > That's all given to "classical mechanics". > > So, anyways, "curved space-time", is a mental model > about the universal law of gravitation and > a classical model of classical mechanics, of it, > and then also "and photons follow world-lines > like test-masses". > > That's all there is to it, yet, there's another > theory, that has all the same actions, where > space is a frame and a frame is also space, > and objects in motion and massy-bodies are, > ..., mostly space, and their space goes along > with them. This then is in a space, a great > altogether flat, as empty, with potential > about orbits the geodesy, that the model > of space-time as, "curved", is, dispensable. > > Then there's the cosmological constant > "vanishing, yet, non-zero: an infinitesimal" ========== REMAINDER OF ARTICLE TRUNCATED ==========