Hi David Bonnell Anything that moves through spacetime is physical. Simple as that.

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[Roger Clough], [rclo...@verizon.net] 1/17/2013 "Forever is a long time, especially near the end." - Woody Allen ----- Receiving the following content ----- From: David Bonnell Receiver: dfine Time: 2013-01-16, 15:44:10 Subject: Re: Are EM waves and/or their fields physical ? The speed of light is altered when photons move in a medium whose index of refraction is greater than that of the vacuum ("raw" space). This change is what causes alterations in the movement of light as it passes through, for instance, lenses. is the relation, where n is refractive index, c is the (maximal) speed of light in vacuum, and v is the propagation velocity on a medium of refractive index n. The SIMPLEST internet search can uncover lots more about the simple physics involved. The fact that light speed can be retarded by its passage through a medium has little to do with the fundamental reality that the speed of light is a constant in free space. The idea of "light" (EM fields) as waves is the result of the great successes of Maxwell's equations, which deal with EM phenomena as continuous fields. That theory, as successful as it was, is not the final word, and has been superseded by Quantum Electrodynamics (QED), which yields Maxwell's equations on scales where the underlying quantum effects are negligible. QED is also a field theory, and there are philosophical issues to be considered when wondering whether fields are in fact "real" or are just another level above the "true" underlying reality. But that sort of philosophical musing is not something that words will handle - there are strong physical and mathematical reasons why gauge theories (QED and the other model equations of the Standard Model are all gauge theories - not to mention current work in areas such as string theory) are thought at present to be the "real" way the world works, and until one understands those issues, talking about reality as a philosophical issue is just BSing. Lots of homework here needed first! As for whether photons are real or not, look up the photoelectric effect, and read some of the original papers in the field before you try to decide if you can even consider the question. Einstein's Nobel prize was given for his work here, which is, by most, considered to be the definitive proof of the quantum nature of light (EM particles). The problem with waves is tied up in older thinking about wave-particle duality. The particles do not have any confusion, and obey both behaviors at the same time. It is our mathematical weaknesses that at the scales we can deal with, we often have to use whichever model is easiest, for the phenomena we are exploring. Not the fault of the underlying reality, just our limitations. As to whether space is some sort of fabric (the general idea is whether space itself is quantized, that is whether the closest adjacent points have some physical separation [a popular idea is that the Planck distance is that minimum separation]) or whether space is continuous (fabric, sort of by definition is NOT continuous), that is a deep subject linked to current theoretical research. We do NOT "know" that it is a fabric. Experimental testing of the concept is so far away, many researchers in the field consider that any direct detection of quantized space may be impossible. Our current highest resolution probe is working at something like the order of 10^-18 m, I think, and the Planck length is of the order of 10^-43 m. Most experimentalists think we would need an accelerator of interstellar size to resolve that depth. Astrophysics, which does explore physics on galactic and larger sizes may be our best hope of some sort of phenomenon that deals with energies on that scale. After all, we do see cosmic rays (protons, mostly) that carry energies higher than current theory suggests is possible. Certainly very much higher energies than we can create in the lab. But not a very tractable tool, by today's standards. As for what light is, keep in mind that we do know (with a very high degree of assuredness) that light consists of quantum particles, and that those particles move along geodesic paths through whatever medium they encounter. Among other things, this implies that from the photon's point of view, it is everywhere it travels in zero time, and to some extent can be thought of as a standing wave. Thus, even though photons can be annihilated and created, while they exist (for astronomical times in the case of light from distant sources) they are a single entity. While current (general relativity) theory does treat space as a deformable medium ("mass tells space how to curve, and space tells mass how to move"), the question of the "density" of space is not part of that theory. The closest the equations treat is the concept of pressure, and that is an issue only for very strong gravity situations, where general relativity probably is not the "real" theory. Most expect that General Relativity (GR) is an excellent continuous approximation to a deeper quantum relativistic theory that we have only vague clues about at present. As for whether GR brought the aether back, that is pretty much nonsense. Photons do NOT need medium to propagate in, and nature of the curvature of "space" is all about its intrinsic geometric properties, not about its structure or physical nature. There is no particular need for space to have any kind of physical reality )like a fabric) to have non-euclidian geometry ("warpage"). And, we are pretty sure from astrophysics at present that on large scales, space is really, REALLY flat (something of the orders of less than one part in 10^60 warpage on the largest scales). Just because the math deals with geometry, there is no more need for a physical material to be involved than there is in the formalism of Euclidean geometry for there to be a piece of paper on which to construct the theorems and objects dealt with in the theory. Think about it. Trying to use analogies, as the author below is doing, is way too far from reality to even be useful as a model. Physics as a science has developed really sophisticated mathematical models and tools for exactly the kinds of questions being dealt here, and until you all delve deeply enough into these tools to know what we know (and don't know) you might as well be consulting crystal balls for insight. It is just a great mistake to develop models that lack the centuries of developed mathematical tools we have today as it is to try to fix a complex problem with a modern car with no tools but your mind. Without a code reader, you can't even tell the general area of the trouble, much less disassemble it and fix it. From: "dfine" <dfin...@charter.net> To: "makoilaci" <makoil...@gmail.com>, "derek abbott" <bu...@hotmail.com> Cc: "Roger Clough" <rclo...@verizon.net>, everything-list@googlegroups.com, mindbr...@yahoogroups.com, "Yuksel Altinok" <yuksel.alti...@gmail.com>, wsturg...@gmail.com, "The Zapster" <rsz...@gmail.com>, rffar...@gmail.com, "Robert King" <rak...@sbcglobal.net>, k...@consolidated.net, "John Wagner" <johnwag...@verizon.net>, farm...@hotmail.com, "Eric Stroud" <eric_str...@email.com>, akis...@ag.tamu.edu, dwbonn...@bigfoot.com, dwbonn...@comcast.net Sent: Monday, January 14, 2013 11:09:19 AM Subject: RE: Are EM waves and/or their fields physical ? Did they not a few years ago prove light is NOT constant? They did slow it and actually stop it going thru different mediums. Thus light is not constant. Consider, we know Space is not empty, there is a fabric or something. At least we know this for the Galaxy. But what about the Universe? Is there the same fabric all thru the universe? But when compressed does it effect light differently? Does this fabric have an effect on light when compressed? Or does light simply follow the path of the fabric? Does gravity compress the fabricate or simply bend it? If it is gravity that effects light without affecting the Fabric, then light here on the planet is not the same as light far between the Stars. Maybe it is the fabric that is around all planets and stars which bends light and slows it. If it is, then light far from gravitational sources should travel at different rates thru the fabric assuming the fabric is denser in some places. From: makoilaci [mailto:makoil...@gmail.com] Sent: Wednesday, January 09, 2013 8:54 PM To: derek abbott Cc: Roger Clough; everything-list@googlegroups.com; mindbr...@yahoogroups.com; Yuksel Altinok; wsturg...@gmail.com; The Zapster; rffar...@gmail.com; Robert King; k...@consolidated.net; John Wagner; farm...@hotmail.com; Eric Stroud; Doug Fine; akis...@ag.tamu.edu; dwbonn...@bigfoot.com; dwbonn...@comcast.net Subject: Re: Are EM waves and/or their fields physical ? only in gravitation curved and the curve itself is debated; not enough experimental proof. Read Brillouin. -- On Wed, Jan 9, 2013 at 2:18 PM, derek abbott <bu...@hotmail.com> wrote: Curved space-time Though I wouldn't like to call it aether. > Date: Wed, 9 Jan 2013 11:15:42 -0600 > Subject: Re: Are EM waves and/or their fields physical ? > From: makoil...@gmail.com > To: rclo...@verizon.net > CC: everything-list@googlegroups.com; mindbr...@yahoogroups.com; > yuksel.alti...@gmail.com; wsturg...@gmail.com; rsz...@gmail.com; > rffar...@gmail.com; rak...@sbcglobal.net; k...@consolidated.net; > johnwag...@verizon.net; farm...@hotmail.com; eric_str...@email.com; > dfin...@charter.net; bu...@hotmail.com; akis...@ag.tamu.edu; > dwbonn...@bigfoot.com; dwbonn...@comcast.net > > just the opposite. general relativity brought aether back, but it is > 4-dimensonal. > > -- > > On Wed, Jan 9, 2013 at 6:04 AM, Roger Clough <rclo...@verizon.net> wrote: > > Bruno, > > > > Another matter is that since the michaelson-morley experiment, > > space itself does not exist (is nonphysical). There is no aether. > > Electromagnetic waves propagate through nothing at all, > > suggesting to me, at least, that they, and their fields, are > > nonphysical. > > > > [Roger Clough], [rclo...@verizon.net] > > 1/9/2013 > > "Forever is a long time, especially near the end." - Woody Allen <SNIP> -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.