Comments on: Light Cone http://asymptotia.com/2007/01/21/light-cone/ Sun, 12 Oct 2008 19:05:42 +0000 http://wordpress.org/?v=2.5.1 By: Michael Breach http://asymptotia.com/2007/01/21/light-cone/#comment-123032 Michael Breach Fri, 11 Jul 2008 04:22:55 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-123032 Light cones are in fact geometrical boundaries of the universe. We are in a geometrically closed/boarded space relative to time and the spatial dimensions. since nothing limits extra dimensions including time, we are so to speak in a black hole relative to the infinity of possibilities. QM is the result of an object hitting the boundary of this spatial enclosure and consequently flattening out so to speak as to paint the entire geometric boundary and being everywhere relative to it, but at certain places with greater certainty. This flattening out is observed as electro magnetic radiation. objects with appreciable mass can never reach this boundary due to the limiting laws of special reality, and the infinite energy required. Light cones are in fact geometrical boundaries of the universe. We are in a geometrically closed/boarded space relative to time and the spatial dimensions. since nothing limits extra dimensions including time, we are so to speak in a black hole relative to the infinity of possibilities.

QM is the result of an object hitting the boundary of this spatial enclosure and consequently flattening out so to speak as to paint the entire geometric boundary and being everywhere relative to it, but at certain places with greater certainty. This flattening out is observed as electro magnetic radiation. objects with appreciable mass
can never reach this boundary due to the limiting laws

of special reality, and the infinite energy required.

]]> By: Clifford http://asymptotia.com/2007/01/21/light-cone/#comment-116128 Clifford Tue, 22 Apr 2008 23:06:01 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-116128 No. Not at all. This is a common misunderstanding. Quantum teleportation still requires information to be send by regular (light or sublight) channels in order to work. So it does not violate the light cone. Sorry to disappoint. -cvj No. Not at all. This is a common misunderstanding. Quantum teleportation still requires information to be send by regular (light or sublight) channels in order to work. So it does not violate the light cone. Sorry to disappoint.

-cvj

]]> By: JAG http://asymptotia.com/2007/01/21/light-cone/#comment-116110 JAG Tue, 22 Apr 2008 19:32:58 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-116110 Hello quantum teleportation!!! We can send the photons at 4c down coax cable That ought to mess with your cones!!! Hello quantum teleportation!!!
We can send the photons at 4c down coax cable
That ought to mess with your cones!!!

]]> By: Rich http://asymptotia.com/2007/01/21/light-cone/#comment-46435 Rich Sun, 20 May 2007 08:20:20 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-46435 People who enjoy this post might also like my series on physics, part of which covers special relativity through spacetime diagrams. The relevant articles begin with <a href="http://www.theculture.org/rich/sharpblue/archives/000182.html" rel="nofollow">"Spacetime and Coordinates"</a> and from there explain the relativity of simultaneity, absolute pasts and futures, the relationship between relativity and causality, time dilation and length contraction. People who enjoy this post might also like my series on physics, part of which covers special relativity through spacetime diagrams. The relevant articles begin with “Spacetime and Coordinates” and from there explain the relativity of simultaneity, absolute pasts and futures, the relationship between relativity and causality, time dilation and length contraction.

]]> By: Sarthak Dasadia http://asymptotia.com/2007/01/21/light-cone/#comment-42671 Sarthak Dasadia Thu, 03 May 2007 14:31:52 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-42671 we can easily imajin and guess all about the future light cone but its really very much difficult to make the physical interpreatation of the past light cones. Past light cone , the things tht can effect ... wat we can interpret it ?? and specially in the case of the light cones how can the things effect on the source of light before emmiting the light beam ? we can easily imajin and guess all about the future light cone but its really very much difficult to make the physical interpreatation of the past light cones. Past light cone , the things tht can effect … wat we can interpret it ?? and specially in the case of the light cones how can the things effect on the source of light before emmiting the light beam ?

]]> By: Centauri Dreams » Blog Archive » Philosophia Naturalis #6 Now Online http://asymptotia.com/2007/01/21/light-cone/#comment-26661 Centauri Dreams » Blog Archive » Philosophia Naturalis #6 Now Online Fri, 02 Feb 2007 18:45:11 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-26661 [...] Carnivals like this one seem to be gaining popularity, a welcome thing because they offer pointers to sites I hadn’t known about, and the topics are always interesting. Good coverage of the American Astronomical Society meeting shows up here, along with work on dark matter, the Antikythera Mechanism, and a wonderful explanation of light cones and Einsteinian relativity. I’m pleased that Philosophia Naturalis includes two recent posts on the James Webb Space Telescope from these pages. [...] [...] Carnivals like this one seem to be gaining popularity, a welcome thing because they offer pointers to sites I hadn’t known about, and the topics are always interesting. Good coverage of the American Astronomical Society meeting shows up here, along with work on dark matter, the Antikythera Mechanism, and a wonderful explanation of light cones and Einsteinian relativity. I’m pleased that Philosophia Naturalis includes two recent posts on the James Webb Space Telescope from these pages. [...]

]]> By: Doug http://asymptotia.com/2007/01/21/light-cone/#comment-25417 Doug Thu, 25 Jan 2007 02:44:02 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25417 Why not think of light cones as catenoids, which some use to describe de Sitter spacetime? [Derek K. Wise, MacDowell-Mansouri gravity and Cartan geometry, page 6 diagram.] http://xxx.lanl.gov/abs/gr-qc/0611154 Does our future really not consist of the intersection of continuous past light cones. The sun light cone is estimated to be at least about 8 minutes old when viewed in every future second. Other light cones are at least light years away. Why not think of light cones as catenoids, which some use to describe de Sitter spacetime?
[Derek K. Wise, MacDowell-Mansouri gravity and Cartan geometry, page 6 diagram.]
http://xxx.lanl.gov/abs/gr-qc/0611154

Does our future really not consist of the intersection of continuous past light cones. The sun light cone is estimated to be at least about 8 minutes old when viewed in every future second. Other light cones are at least light years away.

]]> By: Check Your Light Cone - Asymptotia http://asymptotia.com/2007/01/21/light-cone/#comment-25355 Check Your Light Cone - Asymptotia Wed, 24 Jan 2007 15:07:15 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25355 [...] On the comment stream of my Light Cone post, commenter Neil pointed out something you may find amusing. I quote: At this website, you can generate an RSS feed of your personal light cone (starting from your date of birth), which notifies you when it passes a stellar object. Quite cool! [...] [...] On the comment stream of my Light Cone post, commenter Neil pointed out something you may find amusing. I quote: At this website, you can generate an RSS feed of your personal light cone (starting from your date of birth), which notifies you when it passes a stellar object. Quite cool! [...]

]]> By: Clifford http://asymptotia.com/2007/01/21/light-cone/#comment-25311 Clifford Wed, 24 Jan 2007 00:06:56 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25311 I refer all readers to an earlier thread where several physicists addressed Louise's unorthodox suggestions about Relativity and the constancy of the speed of light. The suggestions were not found to hold water. Follow the discussion in the thread of <a href="http://asymptotia.com/2006/11/20/the-paper/" rel="nofollow" rel="nofollow" rel="nofollow" rel="nofollow" rel="nofollow">this post</a>, and the links therein. -cvj I refer all readers to an earlier thread where several physicists addressed Louise’s unorthodox suggestions about Relativity and the constancy of the speed of light. The suggestions were not found to hold water. Follow the discussion in the thread of this post, and the links therein.

-cvj

]]> By: Louise http://asymptotia.com/2007/01/21/light-cone/#comment-25300 Louise Tue, 23 Jan 2007 21:32:03 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25300 Contrary to popular belief, a constant speed of light is not necessary for Relativity. The Man himself said constant c is "neither a supposition nor a hypothesis about the physical nature of light, but a stipulation which I can make at my free discretion to arrive at a definition of simultaneity." (The Collected Papers of Albert Einstein, Vol. 6, Princeton U. Press, 1996, p. 439) Contrary to popular belief, a constant speed of light is not necessary for Relativity. The Man himself said constant c is “neither a supposition nor a hypothesis about the physical nature of light, but a stipulation which I can make at my free discretion to arrive at a definition of simultaneity.” (The Collected Papers of Albert Einstein, Vol. 6, Princeton U. Press, 1996, p. 439)

]]> By: Matti Pitkanen http://asymptotia.com/2007/01/21/light-cone/#comment-25257 Matti Pitkanen Tue, 23 Jan 2007 07:23:49 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25257 Some facts about light-cone boundary of 4-D Minkowski space which for some reason have not catched attention of physicists. Light-cone boundary, the moment of big bang at the limit of empty Robertson-Walker cosmology, is topologically 3-D but metrically 2-D and therefore allows an extension of 2-D conformal symmetries. Decomposing light-cone as S^2xR_+, where R_+ represents light-like radial direction, you get conformal symmetries of 2-sphere plus new kind of symmetry mathematically very analogous to conformal symmetry associated with the light-like radial coordinate. The isometries extend to infinite-D group: conformal transformations with conformal scaling compensated by suitable radial scaling. These magic properties select 4-D Minkowski space to a a completely unique position since they provide a way of circumventing the no go theorems justifying the belief that strings are fundamental objects. I am still wondering is it really possible that despite my considerable efforts I have not been able to communicate these simple facts to them or do they really refuse to take these simple facts seriously. More generally, light-like 3-surfaces of Minkowski space or more general spaces of form H= M^4xS, share the same properties and Kac-Moody symmetries can be understood as local variants of isometries respecting the light-likeness property. In TGD the like 3-surfaces of M^4xCP_2 are indeed fundamental dynamical objects and a huge generalization of string model conformal symmetries is implied together with the explanation for the 4-dimensionality of space-time and of standard model quantum numbers. These generalized super-conformal symmetries are implied if one accepts quantum gravitational holography in the sense that physical states can be expressed using data at boundaries of light-cone(s actually) and in the sense that light-like boundaries of more general causal horizons of space-time surfaces code for the quantum physics and space-time interior only provides classical correlates for this quantum physics. Those theorists willing to challenge the decision that M-theory is the only possible theory of everything are wellcome to my home page at http://www.helsinki.fi/~matpitka/ containing 15 books about TGD and its applications or to my blog at http://matpitka.blogspot.com. Matti Pitkanen Some facts about light-cone boundary of 4-D Minkowski space which for some reason have not catched attention of physicists.

Light-cone boundary, the moment of big bang at the limit of empty Robertson-Walker cosmology, is topologically 3-D but metrically 2-D and therefore allows an extension of 2-D conformal symmetries. Decomposing light-cone as S^2xR_+, where R_+ represents light-like radial direction, you get conformal symmetries of 2-sphere plus new kind of symmetry mathematically very analogous to conformal symmetry associated with the light-like radial coordinate. The isometries extend to infinite-D group: conformal transformations with conformal scaling compensated by suitable radial scaling.

These magic properties select 4-D Minkowski space to a a completely unique position since they provide a way of circumventing the no go theorems justifying the belief that strings are fundamental objects. I am still wondering is it really possible that despite my considerable efforts I have not been able to communicate these simple facts to them or do they really refuse to take these simple facts seriously.

More generally, light-like 3-surfaces of Minkowski space or more general spaces of form H= M^4xS, share the same properties and Kac-Moody symmetries can be understood as local variants of isometries respecting the light-likeness property. In TGD the like 3-surfaces of M^4xCP_2 are indeed fundamental dynamical objects and a huge generalization of string model conformal symmetries is implied together with the explanation for the 4-dimensionality of space-time and of standard model quantum numbers. These generalized super-conformal symmetries are implied if one accepts quantum gravitational holography in the sense that physical states can be expressed using data at boundaries of light-cone(s actually) and in the sense that light-like boundaries of more general causal horizons of space-time surfaces code for the quantum physics and space-time interior only provides classical correlates for this quantum physics.

Those theorists willing to challenge the decision that M-theory is the only possible theory of everything are wellcome to my home page at http://www.helsinki.fi/~matpitka/ containing 15 books about TGD and its applications or to my blog at http://matpitka.blogspot.com.

Matti Pitkanen

]]> By: Clifford http://asymptotia.com/2007/01/21/light-cone/#comment-25236 Clifford Tue, 23 Jan 2007 03:54:13 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25236 No, that's not correct. The simplification was just to allow me to draw a picture. Going back to 3+1 dimensions just adds a spatial dimension back, and the circle is a sphere. The lightcone in any number of dimensions is just as simple. You mentioned symmetry. Indeed, it is more elegant to think about this all using the Lorentz transformations, which preserve the structure of the lightcone. Cheers, -cvj No, that’s not correct. The simplification was just to allow me to draw a picture. Going back to 3+1 dimensions just adds a spatial dimension back, and the circle is a sphere. The lightcone in any number of dimensions is just as simple. You mentioned symmetry. Indeed, it is more elegant to think about this all using the Lorentz transformations, which preserve the structure of the lightcone.

Cheers,

-cvj

]]> By: Pioneer1 http://asymptotia.com/2007/01/21/light-cone/#comment-25234 Pioneer1 Tue, 23 Jan 2007 03:16:55 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25234 Thanks for your reply. One more question. At some point you simplified to two dimensions and obtained the light cone from that simplification but never went back to spherical. I am not sure and I have to think about this more, but I believe there may be a difference. For instance, if you continue with spherical propagation the lower part of the cone as "past" does not make sense since sphere has different symmetry. What am I missing? Thanks for your reply. One more question. At some point you simplified to two dimensions and obtained the light cone from that simplification but never went back to spherical. I am not sure and I have to think about this more, but I believe there may be a difference. For instance, if you continue with spherical propagation the lower part of the cone as “past” does not make sense since sphere has different symmetry. What am I missing?

]]> By: Clifford http://asymptotia.com/2007/01/21/light-cone/#comment-25228 Clifford Tue, 23 Jan 2007 02:40:00 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25228 Stephen Uitti:- Entanglement still does not permit you to communicate signals faster than light. So entangled states are not exempt. As to your other question: You're assuming that the universe is a bunch of matter expanding in a fixed space. This is not the case: The space itself is expanding. See the link that Bee pointed you too. Carl Brannen: I don't really understand your question very well. Events are still events (as defined in the post) in Quantum Mechanics or Quantum field Theory. Cheers, -cvj Stephen Uitti:- Entanglement still does not permit you to communicate signals faster than light. So entangled states are not exempt. As to your other question: You’re assuming that the universe is a bunch of matter expanding in a fixed space. This is not the case: The space itself is expanding. See the link that Bee pointed you too.

Carl Brannen: I don’t really understand your question very well. Events are still events (as defined in the post) in Quantum Mechanics or Quantum field Theory.

Cheers,

-cvj

]]> By: Clifford http://asymptotia.com/2007/01/21/light-cone/#comment-25226 Clifford Tue, 23 Jan 2007 02:32:51 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25226 I did not use it in the post, but you're right, it is important. The fact that the structure I described above remains intact for all observers I can get to by a translation, rotation, or boost to a different velocity is the statement of this fact. The entire framework of Special Relativity is built on this. Experimental verification? Too numerous to mention. It's just about everywhere: It starts with the Michelson-Morley experiment and goes from there. It is built into everything we do with electricity and magnetism, sdo much of what we observe in astrophysics and cosmology, oodles of data from particle physics experiments, and even manifestly into our technology as we comunicate with out satellites, and even use those satellites to locate where we are on planet earth with GPS. Cheers, -cvj I did not use it in the post, but you’re right, it is important. The fact that the structure I described above remains intact for all observers I can get to by a translation, rotation, or boost to a different velocity is the statement of this fact. The entire framework of Special Relativity is built on this. Experimental verification? Too numerous to mention. It’s just about everywhere: It starts with the Michelson-Morley experiment and goes from there. It is built into everything we do with electricity and magnetism, sdo much of what we observe in astrophysics and cosmology, oodles of data from particle physics experiments, and even manifestly into our technology as we comunicate with out satellites, and even use those satellites to locate where we are on planet earth with GPS.

Cheers,

-cvj

]]> By: Pioneer1 http://asymptotia.com/2007/01/21/light-cone/#comment-25225 Pioneer1 Tue, 23 Jan 2007 01:54:26 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25225 Thank your for this post. I realized I have not thought about this for a long time. I have a question. I think that the fundamental assumption of the light cone concept is that the speed of light is independent of the speed of the projector. I was wondering if this assumption was ever verified by an experiment? Thanks Thank your for this post. I realized I have not thought about this for a long time.

I have a question. I think that the fundamental assumption of the light cone concept is that the speed of light is independent of the speed of the projector. I was wondering if this assumption was ever verified by an experiment?

Thanks

]]> By: Aaron F. http://asymptotia.com/2007/01/21/light-cone/#comment-25217 Aaron F. Tue, 23 Jan 2007 00:39:45 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25217 <blockquote>Your apartment is not a party, or any other type of event.</blockquote> Maybe <i>your</i> apartment is not a party... ;)

Your apartment is not a party, or any other type of event.

Maybe your apartment is not a party… ;)

]]> By: Bee http://asymptotia.com/2007/01/21/light-cone/#comment-25198 Bee Mon, 22 Jan 2007 22:15:55 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25198 Hi Stephen, <a href="http://www.astro.ucla.edu/~wright/Dltt_is_Dumb.html" rel="nofollow">you might find this helpful?</a> -B. Hi Stephen,

you might find this helpful?

-B.

]]> By: Stephen Uitti http://asymptotia.com/2007/01/21/light-cone/#comment-25192 Stephen Uitti Mon, 22 Jan 2007 21:02:24 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25192 So how about them quatum entagled objects? Are they exempt from the light cone? So how about them stuff at the edge of the Universe? Is your flashlight beam ever gonna make it there? 299,792.458 kilometres per second. It's not just a good idea - it's the law! Having done an experiment to measure the speed of light, i have to say that getting more than two significant digits is pretty impressive. We were within 3%. Any idea how nine digits were achieved? So, at 370,000 years after the Big Bang, the Universe became transparent, and the CMB (which wasn't yet stretched to microwaves) was sent everywhere at the speed of light. We can see this radiation. That suggests (to me) that either the Universe was bigger than 370,000x2 light years across at that time, or our average speed from that point was faster than light, or the Universe has wraparound topology. Did I miss something? So how about them quatum entagled objects? Are they exempt from the light cone?

So how about them stuff at the edge of the Universe? Is your flashlight beam ever gonna make it there?

299,792.458 kilometres per second. It’s not just a good idea - it’s the law!

Having done an experiment to measure the speed of light, i have to say that getting more than two significant digits is pretty impressive. We were within 3%. Any idea how nine digits were achieved?

So, at 370,000 years after the Big Bang, the Universe became transparent, and the CMB (which wasn’t yet stretched to microwaves) was sent everywhere at the speed of light. We can see this radiation. That suggests (to me) that either the Universe was bigger than 370,000×2 light years across at that time, or our average speed from that point was faster than light, or the Universe has wraparound topology. Did I miss something?

]]> By: Bee http://asymptotia.com/2007/01/21/light-cone/#comment-25149 Bee Mon, 22 Jan 2007 12:59:35 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25149 Ever noticed the 'X' as favicon on my blog? It's not an X - it's a lightcone :-) Very nice post! Ever noticed the ‘X’ as favicon on my blog? It’s not an X - it’s a lightcone :-) Very nice post!

]]> By: Carl Brannen http://asymptotia.com/2007/01/21/light-cone/#comment-25132 Carl Brannen Mon, 22 Jan 2007 08:33:30 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25132 So if the event is a point where a quantum mechanical measurement is to be / was made, should the event be represented by a wave or a particle? Does it matter if the event is discussed "before" or "after" the measurement is made? So if the event is a point where a quantum mechanical measurement is to be / was made, should the event be represented by a wave or a particle? Does it matter if the event is discussed “before” or “after” the measurement is made?

]]> By: Plato http://asymptotia.com/2007/01/21/light-cone/#comment-25129 Plato Mon, 22 Jan 2007 07:15:27 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25129 I certainly appreciate the lesson on <a href="http://upload.wikimedia.org/wikipedia/en/thumb/9/9a/World_line.png/250px-World_line.png" rel="nofollow">light cones</a>. Also, ways in which one may of looked at "<a href="http://en.wikipedia.org/wiki/Closed_timelike_curve" rel="nofollow">how light cones may be used</a>?" I certainly appreciate the lesson on light cones.

Also, ways in which one may of looked at “how light cones may be used?”

]]> By: Neil http://asymptotia.com/2007/01/21/light-cone/#comment-25107 Neil Mon, 22 Jan 2007 01:21:55 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25107 At <a href="http://interconnected.org/home/more/lightcone/" rel="nofollow">this website</a>, you can generate an RSS feed of your personal light cone (starting from your date of birth), which notifies you when it passes a stellar object. Quite cool! At this website, you can generate an RSS feed of your personal light cone (starting from your date of birth), which notifies you when it passes a stellar object. Quite cool!

]]> By: Romain http://asymptotia.com/2007/01/21/light-cone/#comment-25089 Romain Sun, 21 Jan 2007 22:37:43 +0000 http://asymptotia.com/2007/01/21/light-cone/#comment-25089 The post is interesting but Einstein already explained me this concept in one of his books. I actually prefered his more direct introduction, probably because I study scientific subjects, so I am used to this kind of reasoning. But that's not the point of my response. I don't how easy it is for you, but it would be very handy if you could link the small letter indicating a note to the note, and put a similar link backward. When the article is as long as this one, it is not very easy to scroll down to the note and come back to the text. That's my feature request :) The post is interesting but Einstein already explained me this concept in one of his books. I actually prefered his more direct introduction, probably because I study scientific subjects, so I am used to this kind of reasoning.

But that’s not the point of my response. I don’t how easy it is for you, but it would be very handy if you could link the small letter indicating a note to the note, and put a similar link backward. When the article is as long as this one, it is not very easy to scroll down to the note and come back to the text.

That’s my feature request :)

]]>