Mordred Posted September 19, 2016 Share Posted September 19, 2016 (edited) So as not to unintentionally confuse you, I replied to the first part of your post (you added the second part with the equation a few minutes later) I have not studied tensors yet and that equation is actually too hard for me too attempt to understand at this stage (maybe ever ) So the first part of your post did not confuse ,but the second would confuse me if I attempted to understand it properly... Understood GR is tricky to learn. I caught the cross post aspect. However just learning the tensor usages without knowing how to use tensors can give clues. ie anytime you see [latex]\eta [/latex] just remember Minkowskii geometry. Edited September 19, 2016 by Mordred Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 19, 2016 Author Share Posted September 19, 2016 (edited) . Is this sketch , any where near to what could be happening in principle ? Even though the gravitons are virtual particles ( coming into existence and going back into ..) Perhaps those that come into existence and find themselves close to a mass particle ( react, and interact , and remain real for as long as it takes to react with gravity and accelerate a mass particle . When they have done their job , perhaps they return to being virtual ? Mike Edited September 19, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
Klaynos Posted September 20, 2016 Share Posted September 20, 2016 That is not what is meant by virtual particles in this context. They only exist when the force is exchanged. I would strongly suggest that a starting point for trying to understand exchange particles would be to read about them, probably in the context of electromagnetism. Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 20, 2016 Author Share Posted September 20, 2016 (edited) Well if electrons gather around protons , because they are opposite charge , I assumed gravitons gathered around gravity because they were of similar interest to Gravity. But as electrons are sort of move around carriers , so I assumed gravitons were sort of move around carriers of gravity . However , as you say I need to go and do some reading about ' exchange particles ' as well as Cavendish . So where can I move my ' gravitons to' in my drawing ? Are they more based around the centre , or are they in a hidden world , unseen until needed? New picture ? . Old picture ? Or something completely different ? Mike Edited September 20, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
studiot Posted September 20, 2016 Share Posted September 20, 2016 (edited) Good morning, Mike. I don't think Klaynos meant that gravitons are (electrically) charged. You may be nearer the mark than you realise with this observation MSC or are they in a hidden world Did you see my post#93, there seems to be some diversionary stuff from your original thread going on? Where would you place the force vectors on your drawing in a Newtonian explanation? In further response to your request for tabletop experiments, I watched the Discovery Channel film "Inside Planet Earth" last night and they show several such experiments concocted at research institutes. Edited September 20, 2016 by studiot Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 20, 2016 Author Share Posted September 20, 2016 (edited) Good morning, Mike. I don't think Klaynos meant that gravitons are (electrically) charged. You may be nearer the mark than you realise with this observation Did you see my post#93, there seems to be some diversionary stuff from your original thread going on? Where would you place the force vectors on your drawing in a Newtonian explanation? In further response to your request for tabletop experiments, I watched the Discovery Channel film "Inside Planet Earth" last night and they show several such experiments concocted at research institutes. You are going to have to go through this in depth with me . Unfortunately missed program . Discovery ? Is that on sky or free view ? ( I only have free view . Perhaps we could meet and discuss. Off to radio amateurs meeting this morning ! Yes saw post # 93 . Again need to discuss! Mike Edited September 20, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
Klaynos Posted September 20, 2016 Share Posted September 20, 2016 Well if electrons gather around protons , because they are opposite charge An interaction mediated by virtual photons. , I assumed gravitons gathered around gravity because they were of similar interest to Gravity. No. Gravitons are the force exchange particles (assuming they exist). Similar to virtual photons in QED. Not elections. But as electrons are sort of move around carriers , so I assumed gravitons were sort of move around carriers of gravity Electrons have charge they are not an exchange particle. This therefore makes sense. . However , as you say I need to go and do some reading about ' exchange particles ' as well as Cavendish . So where can I move my ' gravitons to' in my drawing ? Are they more based around the centre , or are they in a hidden world , unseen until needed? They're virtual. Really we don't know enough about gravitons to answer firmly but assuming they are similar to virtual photons their virtual existence is between interacting particles. New picture ? Or something completely different ? Mike Completely different. Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 20, 2016 Author Share Posted September 20, 2016 (edited) . Eek ! I am on a bus , and if I work on my I pad , I feel very sick ! I think this has something to do with my inner ear , eyes and orientation discordance ! As I work , think and reason in pictures ! Unlike many others , who think and reason in words and maths ! There is a message here ? Somewhere .......... ...........Arrived at Radio Society Breakfast .......... I have brought this subject up in the Radio Society . Some members have had careers in space projects . I am horrified , that , nobody , world wide , knows what gravitons are , or whether they even exist at all. They are happy that fields exist , like EM fields and GRAVITATIONAL fields exist . But what the forces ARE , in those fields , quite like ELECTRO MAGNETIC and GRAVITATIONAL FIELDS ....ARE ... they are of a mind , that Nobody , really knows quite what those FIELDS ARE . Yes, they exist , they can be modelled by maths ,mbut WHAT quite they are ....... At the moment Unknown . Yes, there is maths to model them , but what they ARE ? Their nature ? No body seems to know ! Yet ! ......... I think I will go out and shoot myself ! ........ Joking Mike Edited September 20, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
swansont Posted September 20, 2016 Share Posted September 20, 2016 What does all this have to do with a table-top experiment? Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 20, 2016 Author Share Posted September 20, 2016 (edited) What does all this have to do with a table-top experiment?.Well it has everything to do with table top experiments ? I was going to try and use a real life observation of a VISIBLE EFFECT of GRAVITY in action . To see if I could possible focus in on anything to do with GRAVITATIONAL FIELD . and or GRAVITONS . Everybody seems to think or be saying that both are nearly totally UNKNOWN . Yes maths can model . But as regards what they both are , nobody seems to know . So how can I find something , that I do not know what I am looking for ? My colleagues here , say, I might as well go looking for little green fairies! Mike Come on now ! I have an observable experiment . Employing GRAVITY, GRAVITATIONAL FIELD , and maybe even GRAVITONS ( If they exist ) . In front of me on a Granite Bench top Experiment ! Edited September 20, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
Strange Posted September 20, 2016 Share Posted September 20, 2016 (edited) I was going to try and use a real life observation of a VISIBLE EFFECT of GRAVITY in action . To see if I could possible focus in on anything to do with GRAVITATIONAL FIELD . and or GRAVITONS . An experiment / observation like this will not tell you anything about possible quantised effects of gravity. We have no evidence for that from the most extreme cases, so you are definitely not going to see it on the table top. Everybody seems to think or be saying that both are nearly totally UNKNOWN . Yes maths can model . But as regards what they both are , nobody seems to know . All we can do is describe what we see. That is all we can EVER do. That is not just gravity or not just science. That is every aspect of life. We can describe what we see, but we cannot ever say anything about what those things "really" are. It is a meaningless question. (And one that philosophers have wasted a great deal of time on.) We know exactly what a field is and how to describe it. Whether it is real or not is (a) unknown and (b) meaningless and © irrelevant. Edited September 20, 2016 by Strange Link to comment Share on other sites More sharing options...
Klaynos Posted September 20, 2016 Share Posted September 20, 2016 My colleagues here , say, I might as well go looking for little green fairies! Piskies, not fairies... They get very grumpy if you call them fairies... Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 20, 2016 Author Share Posted September 20, 2016 I am not going to give up or be beaten on this one . It's too important . And after all , it is all around us , dictates our every move in life ! There has got to be a hint , somewhere of ......it ....... Gravity? And in my experiment it is so sensitive! Mike Ps I have also made an observation , while walking to the bus . Nobody is ' whistling ' any more . Link to comment Share on other sites More sharing options...
studiot Posted September 20, 2016 Share Posted September 20, 2016 strange post#111 That is all we can EVER do. That presupposes we cannot think rationally. Link to comment Share on other sites More sharing options...
swansont Posted September 20, 2016 Share Posted September 20, 2016 I am not going to give up or be beaten on this one . It's too important . And after all , it is all around us , dictates our every move in life ! There has got to be a hint , somewhere of ......it ....... Gravity? And in my experiment it is so sensitive! Mike Ps I have also made an observation , while walking to the bus . Nobody is ' whistling ' any more . Then tell us what you are measuring (what are the observables) and what the measurement sensitivity will be in your experiment. Link to comment Share on other sites More sharing options...
Strange Posted September 20, 2016 Share Posted September 20, 2016 That presupposes we cannot think rationally. It is thinking rationally that tells us we can never know anything about what things "really" are. It's too important . And after all , it is all around us , dictates our every move in life ! It is important to be able to understand it and describe it and make use of it. And we can do all those things. You are chasing unicorns. And that is not important. It is a waste of time. Unless you want to find a philosophy forum instead of a science one. In fact there is a thread here on this very subject that has been going on for even longer than this one: "Is Space-Time a Physical Entity or a Mathematical Model?" http://www.scienceforums.net/topic/97105-is-space-time-a-physical-entity-or-a-mathematical-model/ And it could go on forever because there is no answer to the question. Link to comment Share on other sites More sharing options...
ajb Posted September 20, 2016 Share Posted September 20, 2016 (edited) They're virtual. Really we don't know enough about gravitons to answer firmly but assuming they are similar to virtual photons their virtual existence is between interacting particles. When people talk about gravitons they are usually thinking in terms of quantum general relativity - that is applying the rules of quantum field theory to general relativity. The method is to linearise Einstein's field equations and then use perturbation theory to get at the quantum theory. The problem is that there is no way to renormalise the theory, so you have to think of the theory as effective, that is we accept that it can only hold reasonably for a small range of energies - we accept that at higher energy some new physics must come into play. However, it is possible to deal with the gravitational force up to 2-loops. Thus, we do have some workable handle on what one means by gravitons. But of course we do not have any experimental evidence that they exist, the closest has to be observations of gravitational radiation. The analogy here is that light waves and photons. ------------------------------------------------------------- The question of if we could ever have a table top experiment that could detect quantum effects of the gravitational force is another issue. Edited September 20, 2016 by ajb Link to comment Share on other sites More sharing options...
studiot Posted September 20, 2016 Share Posted September 20, 2016 (edited) studiot, on 20 Sept 2016 - 12:47 PM, said: Quote strange post#111 That is all we can EVER do. That presupposes we cannot think rationally. Strange post#116 It is thinking rationally that tells us we can never know anything about what things "really" are. I cannot support this conclusion generally or that it can be drawn from what I said (including the context) Edited September 20, 2016 by studiot Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 20, 2016 Author Share Posted September 20, 2016 When people talk about gravitons ......the closest has to be observations of gravitational radiation. The analogy here is that light waves and photons.-------------------------------------------------------------The question of if we could ever have a table top experiment that could detect quantum effects of the gravitational force is another issue. What and where has. GRAVITATIONAL RADIATION .... What was seen ? Mike Link to comment Share on other sites More sharing options...
Strange Posted September 20, 2016 Share Posted September 20, 2016 What and where has. GRAVITATIONAL RADIATION .... What was seen ? Really? There have been multiple threads on this (inlcuidng one of yours, I believe). https://www.ligo.caltech.edu/news/ligo20160211 1 Link to comment Share on other sites More sharing options...
ajb Posted September 20, 2016 Share Posted September 20, 2016 What Strange has said... Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 20, 2016 Author Share Posted September 20, 2016 (edited) . I am sorry gentlemen , my words and images, have got cross wired . When I read RADIATION . It invoked radio active radiation, radio transmission of RF electro magnetic radiation. I immediately thought , " What's all this radiation , connected with gravity ? " eh , what radiation ? Eh ? Wires crossed, until I reflected , of course you were referring back to our cosmic affairs to do with Gravity , gravity waves , etc , for some reason my mind had segregated those to another issue. It was only on your recent prompt , saying we have already discussed that ! That it jolted me back into the reality of the size of the universe and either end of the size spectrum. Sorry chaps how stupid of me ! What a goon! ................ This does not alter the fact that . Gravity is there , in a field , which can be described by maths , to a certain extent . Where it's coordinates are , it's shape ( curved) , but very little else at this juncture . Having the capacity to support Waves , it is starting to show . Whether , gravitons are there, remains to be proved. Far more must be possible, to be understood , to be gleened, of this Universe Shaping Force ! With this force functioning at my fingertips , I hope I can , think, design and conduct an experiment that is worth while ? Mike Edited September 20, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 21, 2016 Author Share Posted September 21, 2016 (edited) .EXPERIMENT PREPARATION I have reasoned that a reliable datum surface is required. This also has to be in or on a Geodesic . such a datum surface , and geodesic is available on a still surface of water. A geodesic is defined as the shortest distance between two actual points . It is my belief that a water surface will in fact assume a flat yet , slightly curved, geodesic surface ( caused by the distortion of gravity itself .) Geodesic ref. : https://en.m.wikipedia.org/wiki/Geodesic I have looked up the work of Cavendish and his measuring gravity to a very tight tolerance Ref :- cavendish :- https://en.m.wikipedia.org/wiki/Cavendish_experiment . What I am interested in is the very small change in the force of balance of gravity with the (surface of the geodesic) surface of water , with a very small change in height of water : It would seem to me , that flat water ( as in a geodesic curve A ) is flat by virtue of the force of gravity . When it finds a way to move ' down ' by a very small increment , it moves to a ( new geodesic curve B ) . I would suggest there is some measurable yet very small change in the gravitational pull at curve B ? Mike Edited September 21, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
geordief Posted September 22, 2016 Share Posted September 22, 2016 (edited) .EXPERIMENT PREPARATION I have reasoned that a reliable datum surface is required. This also has to be in or on a Geodesic . such a datum surface , and geodesic is available on a still surface of water. A geodesic is defined as the shortest distance between two actual points . It is my belief that a water surface will in fact assume a flat yet , slightly curved, geodesic surface ( caused by the distortion of gravity itself .) What I am interested in is the very small change in the force of balance of gravity with the (surface of the geodesic) surface of water , with a very small change in height of water : It would seem to me , that flat water ( as in a geodesic curve A ) is flat by virtue of the force of gravity . When it finds a way to move ' down ' by a very small increment , it moves to a ( new geodesic curve B ) . I would suggest there is some measurable yet very small change in the gravitational pull at curve B ? Have you been following the Lake Balaton thread? http://www.scienceforums.net/topic/98386-laser-curvature-test-on-lake-balaton/page-10 A bit (lot) technical for me but is the subject area a bit similar at all to what you are talking about ? A trivial detail ,perhaps but the water surface is apparently described as "level" ,not flat. Perhaps the level of detail (no pun intended)in that thread will interest you. . Edited September 22, 2016 by geordief Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted September 22, 2016 Author Share Posted September 22, 2016 (edited) Have you been following the Lake Balaton thread? http://www.scienceforums.net/topic/98386-laser-curvature-test-on-lake-balaton/page-10 A bit (lot) technical for me but is the subject area a bit similar at all to what you are talking about ? A trivial detail ,perhaps but the water surface is apparently described as "level" ,not flat. Perhaps the level of detail (no pun intended)in that thread will interest you. . .As regards the Balaton Laser project . I noticed it , thought they may be trying to lead their project toward understanding gravity. But I have not read that much of it , as it sounded more about the technology of laser work over distance and seas . When I get the time I will try and follow more of it ! Needless to say , it sounds an interesting and exciting project . Sometimes / always , I find it difficult to read everything . I have tried to get a software writer to do some form of reading program , as I like pictures, as they take you straight to the project essence . As regards my possible (water surface ) approach . I am thinking it is a way of getting a hold on the correct orientation for gravity experiments , as are plumb lines . Also if Balaton project is proving the geodesic line of the surface of the lake , great ! My surface will probably range from 1 meter to 10 meters. Then I want to see if it's possible to obtain any ' nature of gravity ' aspects . Mike Edited September 22, 2016 by Mike Smith Cosmos Link to comment Share on other sites More sharing options...
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