Fred56 Posted October 17, 2007 Share Posted October 17, 2007 “...we are entering an Era III of physics based on information ...and meaning. For example, the surface area, or irreducible mass of a black hole—a quantity ostensibly as classical as anything...--is now known to measure the entropy of that black hole or, otherwise stated, the number of distinct ways in which such ...can be put together. Information itself, ...is not pure ethereal nothingness, but of necessity has mass. Quantum theory instructs us that there is not a sight we see, an impression we register, an event we detect, which does not go back to elementary quantum phenomena.” -John A. Wheeler Quantum information isn't massless... Link to comment Share on other sites More sharing options...
Klaynos Posted October 17, 2007 Share Posted October 17, 2007 What? Link to comment Share on other sites More sharing options...
Fred56 Posted October 17, 2007 Author Share Posted October 17, 2007 Arcangelo Rossi Dipartimento di Fisica, Universit` di Lecce, Via Arnesano, I-73100 Lecce, Italy It is known that there is no possibility of transmitting information with-out a certain amount of energy. This is arbitrarily small in Classical Physics, due to the continuous nature of the energy parameter, while one cannot reduce that amount below Planck’s energy quanta in Quantum Physics. In short, one cannot send less than a photon from a place to another when transmitting a minimum of information. However, as single photons are never completely de- fined simultaneously in all their parameters as position and momentum, their exact contribution to the information transmitted cannot be known in advance, but only probabilistically predicted. It's probably something we don't think about, but photons have energy. Information, ultimately, is also energy, or uses it to "carry" a message. You can look at it from the entropy angle too, but it's a bit harder to get. Link to comment Share on other sites More sharing options...
Martin Posted October 17, 2007 Share Posted October 17, 2007 It's probably something we don't think about, but photons have energy. ... You realize they don't have mass? A lot of people do not seem to know that E = mc2 is not a general truth. It does not hold for photons, for example. Because they are not at rest. For the equation to hold the observer frame would have to be one where the photon was at rest, which doesnt happen. Have to go. maybe someone else will explain. information requires energy, but not mass. Link to comment Share on other sites More sharing options...
Fred56 Posted October 17, 2007 Author Share Posted October 17, 2007 Yes, I realise photons are "massless". You do realise you have said that information, which is "massless" photons, doesn't have mass? Sorry, it does (have a mass equivalent). This one is tough for most people, like accepting that time doesn't exist. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted October 17, 2007 Share Posted October 17, 2007 [math]E = \sqrt{(m_0c^2)^2 + (pc)^2}[/math] For a photon, the rest mass [math]m_0[/math] is zero, but the momentum p is not. Link to comment Share on other sites More sharing options...
Klaynos Posted October 17, 2007 Share Posted October 17, 2007 Yes, I realise photons are "massless". You do realise you have said that information, which is "massless" photons, doesn't have mass? Sorry, it does (have a mass equivalent). This one is tough for most people, like accepting that time doesn't exist. Most physicist know that information is convayed by energy, not mass. How are the two related? And why do you say that time does not exist? Because there's quite alot of empirical data which says it does... like urm well yesterday... Link to comment Share on other sites More sharing options...
Fred56 Posted October 18, 2007 Author Share Posted October 18, 2007 More than ninety years after Einstein's earth-shaking discoveries, many still live in the same world these earlier "prophets of the real" (19th century scientists) believed so fervently in. But it is blindingly obvious that information does not come for free. We now understand that all of the “messages” we get from the external world arrive fundamentally because of tiny, quantised bits of energy. We know there is no way to deliver or receive any message without the “transfer” of at least one of these. We also know that time cannot exist, as such. Time is a facet of the way we measure change in the world. Our measurement is not costless but perturbs the very object (also the subject) of itself, of measure. This is actually blindingly obvious to anyone, but we cling to our concepts of a real, external, existential time, “time-stuff” (tachyons, anyone?), which has no existence other than as a concept of measurable change. Link to comment Share on other sites More sharing options...
foodchain Posted October 18, 2007 Share Posted October 18, 2007 Quantum information isn't massless... I just read up on that John Wheeler guy and I would have to say that he is my newest hero along with that Erwin guy... I would like to add in on the post but I will save my words for another forum. I don’t have the physics chops to pipe in really. Link to comment Share on other sites More sharing options...
Fred56 Posted October 18, 2007 Author Share Posted October 18, 2007 Heres the beginning of the essay (the rest is above): A hundred years ago, a young scientist was thinking about our current view of the universe, and decided there was something wrong with it. He spent several years reviewing the thinking and insights into the nature of reality introduced by the theories of James Clerk Maxwell. He developed or adapted his own mathematical symbology, and constructed a theory which would predict the expansion of the universe. For all of human history, man has believed in the existence of both an external and measurable world, and external and measurable time and distance within it. This is coupled, or co-cepted, with the belief that this measurement is “free”, it comes at no cost to either the observer, or the thing observed. There is no perturbation of any system and, conceptually, all information is available. These ideas -of complete information and an external measurable “system” that can be viewed as separate, or isolated, without cost- were thought by many, especially at the close of the 19th century, to be the keys to unlock the secrets of the universe (unfinished)... Link to comment Share on other sites More sharing options...
Sisyphus Posted October 18, 2007 Share Posted October 18, 2007 We also know that time cannot exist, as such. Time is a facet of the way we measure change in the world. It kind of hurts your case when you say something doesn't exist and then describe it in the very next sentence. Some might say that's blindingly obvious. Link to comment Share on other sites More sharing options...
timo Posted October 18, 2007 Share Posted October 18, 2007 It kind of hurts your case when you say something doesn't exist and then describe it in the very next sentence. Some might say that's blindingly obvious. In pseudoscience, you can repair those problems by your very personal definition of "exists" and by axiomatically claiming the term "existance" had a fundamental meaning for the very nature of ... err ... nature. I'd sponatneously think that the amout of emotion put into the term "existance" might serve as a measure of how pseudoscientific a statement is. E.g.: My understanding (and afaik also the canonic understanding in the physics community) of "right-handed neutrinos do not exist" is simply a pragmatic "there is no mathematical term for them in the model (lagrangian) that we use to describe the world". Link to comment Share on other sites More sharing options...
Fred56 Posted October 18, 2007 Author Share Posted October 18, 2007 I was trying to define the non-existence of it (time). It isn't that easy, but I don't think I say: "It doesn't exist" and then: "but it does exist". I say it exists only as a concept. That's an "idea" btw. (that last sentence is recursively "defined by itself" -work that one out?) Link to comment Share on other sites More sharing options...
timo Posted October 18, 2007 Share Posted October 18, 2007 Ok, makes sense. But what is the difference between something that "really exists" in nature and something that is necessary to describe nature? Question to be understood from the standpoint of "science tries to describe nature quantitatively". Link to comment Share on other sites More sharing options...
Fred56 Posted October 18, 2007 Author Share Posted October 18, 2007 “...we can speak equivalently of Information which is defined as the negative of entropy, and representing system order. ...[since] entropy measures the rate of diffusion to a state of disorder..., ...the entropy metric is defined by the order or disorder of topological structure[.]” -J. E. Johnson (in case you need to know...) Link to comment Share on other sites More sharing options...
vincent Posted October 18, 2007 Share Posted October 18, 2007 A lot of people do not seem to know that E = mc2 is not a general truth. It does not hold for photons, for example. Because they are not at rest. For the equation to hold the observer frame would have to be one where the photon was at rest, which doesnt happen. What are you talking about!? There is nothing about the existence of massless particles that implies that the applicability of the mass-energy equivalence is somehow not universal. In fact, it is in terms of the mass-energy equivalence that we understand why there are processes in quantum electrodynamics in which photon energy is converted into electron and positron mass and vice versa. Have to go. Okay, bye. Link to comment Share on other sites More sharing options...
Fred56 Posted October 18, 2007 Author Share Posted October 18, 2007 "...a definition of information entropy for points in metric spaces ...measures the amount of information needed to specify a point of a metric space. For the definition of entropy we need an additional structure on the metric space .., a computable structure. If information sources are considered as a metric space ...entropy has the same value as Shannon['s] ...for almost all points of the space. If general metric spaces are considered there is a relation between entropy and dimension." -S Galatalo (in case anyone's still confused...) Link to comment Share on other sites More sharing options...
fredrik Posted October 18, 2007 Share Posted October 18, 2007 Interesting topic but I didn't get the point? There are alot of quotes and mystical comments /Fredrik Link to comment Share on other sites More sharing options...
Fred56 Posted October 18, 2007 Author Share Posted October 18, 2007 So you feel the concept of information having mass/energy doesn't pose a problem for the determinist/empiricist view? Link to comment Share on other sites More sharing options...
fredrik Posted October 18, 2007 Share Posted October 18, 2007 > So you feel the concept of information having mass/energy doesn't pose a problem for the determinist/empiricist view? The "determinist view" is not a view I have and perhaps that explains why I didn't get the supposedly obvious point IMO, "information having energy", is closely related to the fact that one always have various degrees of confidence in information. That is we get a message, but the question is what is the confidence in the message? This certainly constrains the impact the information of the message can have on the receivers/observers state. Not the striking association to the concept of "inertia". Intertia of an opinon, to resist revision to an incoming possibly compromising message. I rather think the association is excellent and beatiful - not a "problem" at all. It rather may allow for a more distinct definition of energy, in terms of information - at least that's wha'ts in my plans. Currently the notion of energy is not very well defined in the first place - THIS worries me. /Fredrik Link to comment Share on other sites More sharing options...
Fred56 Posted October 19, 2007 Author Share Posted October 19, 2007 something that is necessary to describe nature? Atheist, this is our doing, not "nature's". This is our "mapping" of what "nature has to offer", no? The idea of standing “outside” some observer-defined “system” (a measurable space) and observing it without perturbation; without cost to the observer, the system or the measurement itself, is overdue for a “perception funeral service". But It probably won't get a send-off for a while yet: we seem to still be very much in need of our classical contact-lenses. Here's a sample of current thinking: “ 1. ...information is a state of energy ...in an isolated frame. Information is essential a state of unbalance. 2. Isolation is key. Without isolation no unbalance. One would become zero again without isolation. Isolation means a boundary. Where does the boundary comes from? 3. Next question: Information about what ... coming from where? Clearly from event(s) that what was/were 'before'. So the cause or causing factors. Previous parameters which were excited and caused the unbalanced state of energy. 4. Previous? So there must be history. but: History that STILL HOLDS to fund the present! [cfr. how the historical combinations of atoms (Past) make a specific neurotransmitters-molecule (Now)]. Thus previous information still 'in-corporated' inside the Now-event. 5. Now the prime key however is what is energy? Here we see the heuristic paradox. Correct interpretation of Einstein leads us to conclude that Energy is a specific expression of space-time. So 'sub-energy hold in an isolated frame' means: spacetime incorporated in spacetime. So information is a sub-set of spacetime in relation to a specific level of in another way (hierarchic) expressed spacetime. “ -pelastration (posted in physicsforums) He's trying, but the problem with his approach is that he is still seeing a classical world. In Chaos & Cyberculture, Leary says (according to Arno Ruthofer): Werner Heisenberg's principle states that there is a limit to objective determinacy. If everyone has a singular viewpoint, constantly changing, then everyone creates his or her own version of reality. This gives the responsibility for reality construction not to a bad-natured biblical God or to an impersonal, mechanical process of entropic devolution, or to an omniscient Marxist state, but to individual brains. ...Furthermore, Leary explains that Heisenberg's uncertainty principle "suggests that our observations fabricate the subject matter, i.e. realities. We can only know what our sense-organs, our measuring instruments and our paradigms or maps describe". According to Leary, the "Quantum universe" that Heisenberg and the other quantum physicists define is an observer-created universe. It is a universe that changes when the viewpoint of the observer changes. What's wrong with our model? Either we aren't seeing reality “as it is”, or we need a more “complete” theory. The conservation of quantised properties of mass (spin, charge, superposition) doesn't map to a classical kind of model at all. Our quantum spectacles are either a work in progress, or in need of a good “quantum wipe”. We still wear our classical/analog specs all the time, so it's hard to think about the world of quantised/digitised mass and energy. Link to comment Share on other sites More sharing options...
Royston Posted October 19, 2007 Share Posted October 19, 2007 What's wrong with our model? Either we aren't seeing reality “as it is”, or we need a more “complete” theory. That's your conclusion ? It may have had a bit more weight, say, 90 years ago. Even then, don't you think the response would be 'well yeah, and....?' Link to comment Share on other sites More sharing options...
Fred56 Posted October 19, 2007 Author Share Posted October 19, 2007 No, it isn't my conclusion. This observation (the model is incomplete) was made back in the '30s by Einstein, Podolsky, Bohr, Rosen, et al. And maybe since then, the response (to their observation), might be seen (by some, maybe yourself) as pretty much 'well yeah, and....?' Me, I think we might be a lot closer to resolving this than some. Opinatus sum, of course. And why is there a need for some conclusion? What conclusion, or kind of conclusion, do you feel is needed here? Link to comment Share on other sites More sharing options...
Royston Posted October 19, 2007 Share Posted October 19, 2007 Fred, you started with 'quantum information is mass-less', the thread went off on a tangent when you stated 'time doesn't exist', and now you're talking about the discrepancy (at least I think that's what you've brought up) between classical mechanics and QM. With the latter, you've just regurgitated in a (with all due respect) confused manner, the disparity between the two...so, as with some of your other threads, it just leaves (me at least) the reader thinking, 'ok, we know all this, so what precisely is your point...where is this going ?' There isn't anything to discuss here, I'm not meaning to be rude, but please start a thread with discussion points, not just statements. Apologies if that came across as backbench moderating (is that the right expression), I've just noticed this trend in many of your threads / posts i.e I'm giving you advice. Link to comment Share on other sites More sharing options...
fredrik Posted October 19, 2007 Share Posted October 19, 2007 I have to admit that while the topic is potentially interesting, I have a little hard to understand Fred56:s message. The quotes out of an uncertain context is confusing me at least. You write at one place "he's trying" whom does he refer to? I don't follow the sequence of reasoning, and what does "our model" refer to? Fred, I've seen some of your other posts and I like your questioning of things but to speak for myself your posts are not always easy to read (that probably applies to me as well but anway /Fredrik Link to comment Share on other sites More sharing options...
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