JohnSSM Posted January 11, 2015 Author Posted January 11, 2015 No...they are different radii...The schwartsman radius defines at what volume mass needs to be compressed to create the effects of a BH....the actual event horizon of that black hole does NOT correspond to this size...Wiki does work it wrong...the wording im using does seem to be correct... "The point at which gravitational collapse becomes inevitable is at 9/8 the Schwarzschild radius. This is known as Buchdahl's Theorem -- Schutz's textbook has a section on it. After the mass has collapsed into a black hole, its event horizon will be located at its Schwarzschild radius (assuming it has no angular momentum). "AHA...thats what I was looking for...Earlier in this post, i predict this effect....i didnt know the 9/8ths part but was always wondering what you meant...because you didnt describe it with enough words thoroughly, i didnt get what you were saying...that quoted wording above explains it... Gravitational collapse means event horizon in that example, correct? I use vectors in graphic design...i understand them totally...i have a color red, extend it in this vector of energy to tell me how long the line will be, extend it this vector of angle to describe what direction it goes...
imatfaal Posted January 11, 2015 Posted January 11, 2015 ! Moderator Note John This is getting silly. You are responding within a few seconds of a post - take some time to weigh your arguments. Also take some time to consider that some of the physics community here may be correct. Your posts on black holes are running against all theory - you are gonna need to either back them up and argue them well or retreat from them. Take it slow and read with care the very useful responses you are getting from at least four very knowledgeable members. If three of them and wikipedia agree - it might be time to check your ideas. And schwartsman???? Come on - precision is important in science. Do not respond to this moderation
JohnSSM Posted January 11, 2015 Author Posted January 11, 2015 This is what I have stated about the subject since the beginning..."The schwartsman radius defines at what volume mass needs to be compressed to create the effects of a BH....the actual event horizon of that black hole does NOT correspond to this size..." If you had a certain volume of mass, does it not take energy to compress it? and once it does, does that energy now contribute to its gravitational force?
Mordred Posted January 11, 2015 Posted January 11, 2015 Found this handy reference it does a good job describing the Kerr metric vs the Scwartchild metric. http://www.google.ca/url?sa=t&source=web&cd=5&ved=0CCoQFjAE&url=http%3A%2F%2Fthep.housing.rug.nl%2Fsites%2Fdefault%2Ffiles%2Ftheses%2FBachelor%2520thesis_Pieter%2520van%2520der%2520Wijk.pdf&rct=j&q=kerr%20metric%20geodesic%20equations&ei=i_qyVKiZHpO1yATaloDoAw&usg=AFQjCNF21wPuwdhohT3l93JZfLn9nHEPUg&sig2=EiaKPMj7eD3PjCx5jfKSJw&bvm=bv.83339334,d.aWw it's a fairly easy read, however does include the math details. 1
JohnSSM Posted January 11, 2015 Author Posted January 11, 2015 The moderator hasnt even read enough of the post to see that wiki disagreed with one of the expert members... -1
elfmotat Posted January 11, 2015 Posted January 11, 2015 This is what I have stated about the subject since the beginning... "The schwartsman radius defines at what volume mass needs to be compressed to create the effects of a BH....the actual event horizon of that black hole does NOT correspond to this size..." You have it reversed. The Schwarzschild radius does not define at what radius something will become a black hole. That may vary depending on the specifics of the star/mass/whatever that's undergoing collapse. The radius at which you are guaranteed collapse is at 9/8 its Schwarzschild radius. For a BH with zero angular momentum the event horizon does correspond to its Schwarzschild radius. Gravitational collapse means event horizon in that example, correct? No. It means the matter will collapse in on itself due to its own gravity to form a black hole. A "horizon" means "point of no return." As ajb previously mentioned, the specifics involving the formation of horizons are still not completely known.
JohnSSM Posted January 11, 2015 Author Posted January 11, 2015 Found this handy reference it does a good job describing the Kerr metric vs the Scwartchild metric. http://www.google.ca/url?sa=t&source=web&cd=5&ved=0CCoQFjAE&url=http%3A%2F%2Fthep.housing.rug.nl%2Fsites%2Fdefault%2Ffiles%2Ftheses%2FBachelor%2520thesis_Pieter%2520van%2520der%2520Wijk.pdf&rct=j&q=kerr%20metric%20geodesic%20equations&ei=i_qyVKiZHpO1yATaloDoAw&usg=AFQjCNF21wPuwdhohT3l93JZfLn9nHEPUg&sig2=EiaKPMj7eD3PjCx5jfKSJw&bvm=bv.83339334,d.aWw it's a fairly easy read, however does include the math details. Thanks for that, but im still working on establshing that the EH and schwartzchild radius are not the same for a black hole...and I have all the info I need to do that...
elfmotat Posted January 11, 2015 Posted January 11, 2015 (edited) Thanks for that, but im still working on establshing that the EH and schwartzchild radius are not the same for a black hole...and I have all the info I need to do that... Except that they are (for a black hole with no angular momentum or charge), by the definition of the Schwarzschild radius. Edited January 11, 2015 by elfmotat
JohnSSM Posted January 11, 2015 Author Posted January 11, 2015 (edited) It kinda seems like, gravity collapses over here...but it effects space time collapse over here... Except that they are (for a black hole with no angular momentum or charge), by the definition of the Schwarzschild radius. That does not correspond with wiki..."The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is the radius of a sphere such that, if all the mass of an object were to be compressed within that sphere, the escape speed from the surface of the sphere would equal the speed of light. An example of an object smaller than its Schwarzschild radius is a black hole." It seems the last line should say...."an example of an object whose radius is smaller than its EH radius would be a black hole" The event horizon for earth would be smashing into its surface...in a black hole, you smash into it before you get to the mass... Edited January 11, 2015 by JohnSSM
imatfaal Posted January 11, 2015 Posted January 11, 2015 ! Moderator Note The moderator hasnt even read enough of the post to see that wiki disagreed with one of the expert members... Not responding means not responding. And the moderator has read all of the posts - and I am pretty sure the members, experts and wiki are in accord; you are just misreading wiki. Please take a moment to read what I wrote about the thread. A continued denial to take on board current scientific thinking with nothing more being offered in return other than your imaginings and guesses will lead to the thread being locked. And do not respond to the moderation this time - if you think it is unfair then report it. 1
Strange Posted January 11, 2015 Posted January 11, 2015 The schwartsman radius ... OK, Jonah, that's enough.
JohnSSM Posted January 11, 2015 Author Posted January 11, 2015 (edited) OK, Jonah, that's enough. Strange himself said the wording on wiki was not correct my moderator...i guess you didnt see that entry... See how important OBSERVATION is? wasted on you folk Found this handy reference it does a good job describing the Kerr metric vs the Scwartchild metric. http://www.google.ca/url?sa=t&source=web&cd=5&ved=0CCoQFjAE&url=http%3A%2F%2Fthep.housing.rug.nl%2Fsites%2Fdefault%2Ffiles%2Ftheses%2FBachelor%2520thesis_Pieter%2520van%2520der%2520Wijk.pdf&rct=j&q=kerr%20metric%20geodesic%20equations&ei=i_qyVKiZHpO1yATaloDoAw&usg=AFQjCNF21wPuwdhohT3l93JZfLn9nHEPUg&sig2=EiaKPMj7eD3PjCx5jfKSJw&bvm=bv.83339334,d.aWw it's a fairly easy read, however does include the math details. This is great...on the very first page it describes a BH with infinite amount of density...with infinite curvature...does that mean that the density is infinite in terms of everything else, or just infinite in terms of effecting gravity as much as gravity can be effected?...once you reach this infinite density or curvature, there is no denseness or curvature that could effect spacetime any more than it has been effected...and that sounds very much like "compressing spacetime until it is gone"...but it really takes a mastery of language to understand that... Edited January 11, 2015 by JohnSSM -1
elfmotat Posted January 11, 2015 Posted January 11, 2015 (edited) That does not correspond with wiki... "The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is the radius of a sphere such that, if all the mass of an object were to be compressed within that sphere, the escape speed from the surface of the sphere would equal the speed of light. An example of an object smaller than its Schwarzschild radius is a black hole. It seems the wiki is wrong, or at least poorly worded. If you compress a mass to its Schwarzschild radius it certainly will collapse, but that is not at all its defining characteristic. As I've said, collapse will become inevitable before it is compressed to its Schwarzschild radius. Somebody should probably fix that. EDIT: Upon re-reading, the wiki is not really wrong. The article does not actually mention gravitational collapse, it just says that a mass smaller than its Schwarzschild radius will have an event horizon, which is true. I still think it's a bit badly worded though. Edited January 11, 2015 by elfmotat 1
Strange Posted January 11, 2015 Posted January 11, 2015 (edited) See how important OBSERVATION is? That's great from someone who keeps referring to "schwartsman". This is great...on the very first page it describes a BH with infinite amount of density...with infinite curvature...does that mean that the density is infinite in terms of everything else, or just infinite in terms of effecting gravity as much as gravity can be effected? It just means infinite density. Full stop. As in: the density is infinite. but it really takes a mastery of language to understand that... Which neither you nor the author of that thesis seem to have. (But he has the excuse of writing in a foreign language. And I bet he knows how to spell Schwarzschild.) Edited January 11, 2015 by Strange
JohnSSM Posted January 12, 2015 Author Posted January 12, 2015 (edited) That's great from someone who keeps referring to "schwartsman". It just means infinite density. Full stop. As in: the density is infinite. Which neither you nor the author of that thesis seem to have. (But he has the excuse of writing in a foreign language. And I bet he knows how to spell Schwarzschild.) i am sorry for the schwartzchild mispellings...Can i just say S? To me, math is like spelling...you can still make out the words and understand the concepts if I spell the words wrong... Jsut leik tihs wroks, yuo can sitill udnretsnda waht Im syanig cnat you? Im not following the rules of launguage, but the truth of the expression is still known... Ibe gotten to page 34 because I am a fast reader...very cool graphic about the Radius problem...and Wiki would definitlely be misworded..can i get some slack here? There is some confusion about the S radius and the event horizon location....in this paper, http://thep.housing.rug.nl/sites/default/files/theses/Bachelor%20thesis_Pieter%20van%20der%20Wijk.pdf On page 34 it shows the event horizon INSIDE the mass (stationary surface limit)...how could you ever get to the event horizon if it was within the object? And if the thesis by Van der Wijk is right, then my intuitions have been off...but wikipedia's explanation was confusing me... I got it..that shows a rotating BH...I would love to see a graphic such as this with a non rotating BH but the paper does not provide one... I never said my intuitions could get me all the way to any concept...Im starting with intuitions and noting that which correlates to current knowledge...granted, that knowledge has been gained by math...and lots of observation for sure... If you know that i dont know or understand the math, then presenting math as the language is speaking to me in terms I dont get... We can ban me from the forum for not understanding the math, or ban me for not forcing myself to examine the math to create an understanding...but really fellas...in a conversation where someone doesnt understand math, you cant get very far in communicating with that person in math...so you have to find another means or stop trying...i dont try to have conversations with monkeys...and I dont get mad at them for not being able to understand my language...i just walk away... I just ask that folks communicate with me in ways that i can understand... Im going to study the math...i allready have begun...should i just come back after that? itll be like four years...or can we still have a discussion that includes a language that I understand?...you cant force me to understand what you say with math...but you can help me understand what it means...i think...its allready happened...so is it my patience that is being annoyed? Edited January 12, 2015 by JohnSSM -3
xyzt Posted January 12, 2015 Posted January 12, 2015 (edited) There is some confusion about the S radius and the event horizon location....in this paper, http://thep.housing.rug.nl/sites/default/files/theses/Bachelor%20thesis_Pieter%20van%20der%20Wijk.pdf On page 34 it shows the event horizon INSIDE the mass (stationary surface limit)...how could you ever get to the event horizon if it was within the object? . Well, the Earth's Schwarzschild radius is 9 mm. It is tough that you don't understand basic physics. We can ban me from the forum for not understanding the math, or ban me for not forcing myself to examine the math to create an understanding...but really fellas...in a conversation where someone doesnt understand math, you cant get very far in communicating with that person in math...so you have to find another means or stop trying...i dont try to have conversations with monkeys...and I dont get mad at them for not being able to understand my language...i just walk away.. Goo idea. Im going to study the math...i allready have begun...should i just come back after that? itll be like four years...or can we still have a discussion that includes a language that I understand?... Yes, come back after you learned. Edited January 12, 2015 by xyzt
JohnSSM Posted January 12, 2015 Author Posted January 12, 2015 (edited) i am sorry for the schwartzchild mispellings...Can i just say S? To me, math is like spelling...you can still make out the words and understand the concepts if I spell the words wrong... Jsut leik tihs wroks, yuo can sitill udnretsnda waht Im syanig cnat you? Im not following the rules of launguage, but the truth of the expression is still known... Ibe gotten to page 34 because I am a fast reader...very cool graphic about the Radius problem...and Wiki would definitlely be misworded..can i get some slack here? There is some confusion about the S radius and the event horizon location....in this paper, http://thep.housing.rug.nl/sites/default/files/theses/Bachelor%20thesis_Pieter%20van%20der%20Wijk.pdf On page 34 it shows the event horizon INSIDE the mass (stationary surface limit)...how could you ever get to the event horizon if it was within the object? And if the thesis by Van der Wijk is right, then my intuitions have been off...but wikipedia's explanation was confusing me... I got it..that shows a rotating BH...I would love to see a graphic such as this with a non rotating BH but the paper does not provide one... I never said my intuitions could get me all the way to any concept...Im starting with intuitions and noting that which correlates to current knowledge...granted, that knowledge has been gained by math...and lots of observation for sure... If you know that i dont know or understand the math, then presenting math as the language is speaking to me in terms I dont get...and doing it, knowing it will be useless... We can ban me from the forum for not understanding the math, or ban me for not forcing myself to examine the math to create an understanding...but really fellas...in a conversation where someone doesnt understand math, you cant get very far in communicating with that person in math...so you have to find another means or stop trying...i dont try to have conversations with monkeys...and I dont get mad at them for not being able to understand my language...i just walk away... I just ask that folks communicate with me in ways that i can understand... Im going to study the math...i allready have begun...should i just come back after that? itll be like four years...or can we still have a discussion that includes a language that I understand?...you cant force me to understand what you say with math...but you can help me understand what it means...i think...its allready happened...so is it my patience that is being annoyed? Well, the Earth's Schwarzschild radius is 9 mm. It is tough that you don't understand basic physics. Goo idea. Yes, come back after you learned. If you stuff the earth down to 9mm radius it will become a BH? Thats awesome info...I just think of the energy it would take to do that...awesome... IM the monkey...youre supposed to walk away, not me...language skills and observation failing you...and why dont you if all youre going to do is be mean? monkey abuser! Im gonna make postings and get as much info as I can in my terms...if you all decide to stop responding, then i wont have anyone to discuss with.. I have no control over the moderators or other posters...all I can do it post and discuss the best I can...If its not good enough, they can ban me... Or you can ignore me... I assume if i had the golf ball spin analogy wrong, that someone would correct me...Does this mean my golf ball spin analogy holds true with at least golf balls? FOR ELFOMAT...The "grid" is used all the time in discussions of spacetime geometry... On page 14 of this article, it shows the grid and the gridlines get less spacetime between than is the grid is closest to the source... http://thep.housing.rug.nl/sites/default/files/theses/Bachelor%20thesis_Pieter%20van%20der%20Wijk.pdf are you sure youre not trying to misunderstand me? The grid seems a pretty easy thing to reference in terms of spacetime geometry, but only if you spent lots of time thinkig of it like that...I am not the only one who uses gridlines to express space-time geomtery... I'm sorry to tell you, but you're not going to get any direct meaningful responses to posts like these. It's so full of vague concepts and misconceptions that you're better off addressing what isn't wrong with it than what is. I think you need to start from scratch, ridding your brain of any popsci analogies/explanations you may have come across. This again makes no sense. I don't know what you mean by "a grid," or "disables GR geometry." Such a terms are far too vague to be meaningful. Plus, there is space and time at the event horizon. Who told you there isn't? Who told me there isnt? They describe the spacetime at the point of EH to have "infinite curvature and density"...What does infinite curvature and density mean to you? To me, it meant that infinite density and curvature cannot exist at the same time as space-time coordinates...if they have no density and curve, then the coordinates cannot exist....if they have infinite density and curvature, the same applies...in my mind... you can no longer plot coordinates that have any value or meaning in infinity...whats 30 percent of infinity? if 2 points on a slope are defined in infinity, you cannot find a slope...math is still relative from zero...if you have infinite curvature from the presence of infinite density, you cant put values inside it that have any relative meaning...right? I think, if one understands what they mean by "infinite" in this use, then you could say..."IF we could change the speed of light, we would have to redefine what infinity meant in regards to curvature of space and the density it takes to create that curvature... For all the folks who told me to look into rest mass and inertial mass, you were right...I should have...but it doesnt change my big ole perception...it just helped to make it less fuzzy in detail... Learning is painful...i think I understand now that you all feel like im putting all that pain on you and i get to slam around and do whatever i want without pain...and in that perspective, i am a jerk... I am not avoiding that pain...doing lots of reading and thinking...but, we all do, including myself, know that i'm avoiding the inevitable pain of learning math which is why im actually avoiding doing it...and they way you all act, that pain has changed you...ha! This part is supposed to be fun...talking and discussing... Can anyone tell me the MASS limit or line on this graphic...page 34 of this article... http://thep.housing.rug.nl/sites/default/files/theses/Bachelor%20thesis_Pieter%20van%20der%20Wijk.pdf This guy knows how to write and express! Whoever reccomended that link...either Mordred or strange, its really understandable...was I asking yall to say the same things? yes! "As stated in Section (3.4.1), an event horizon is a surface that can be considered as a one-way-membrane: it lets signals from the outside in, but it prevents signals from the inside to go to the outside. The curvature within the event horizon is that strong, that particles or photons can not escape from there to infinity. As well for the Kerr-metric as for the Schwarzschildmetric is the event horizon a sphere-shaped surface around the black hole singularity. The horizon generators are the photons that have no-endpoints and will for always stay on the horizon. Whereas they follow straight lines for the Schwarzschild black hole, the null-geodesics are twisted for the Kerr black hole: they twist around the horizon, as the twists on a barber-pole (see figure 4.5). This twisting is caused by the frame-dragging: the photons" I like to wax poetic...Feynman said that he beileved all the math could be like a fractal...it just keeps getting more and more specific the farther you take the equations, and that the math may never give us any final amounts that do not need further scrutiny...some variable will always spawn more equations and theories...this is Feynman saying this...if he says it could be true, well...he's my mosted trusted expert... The point being really that you all are deeper into the layers of understanding than I am...for sure...but you cant just pull me down to you...I need to make it through the layers...I need time...but still Im looking for conversation at this moment and level... and also...the fractal can be admired and learned from at every depth... If youre gonna ban me or lock the topic, do it now! that ending was beautiful man! Edited January 12, 2015 by JohnSSM
nobox Posted January 12, 2015 Posted January 12, 2015 It may be unnecessary to bang one’s head over the space-time conundrum, if a different math is adopted. I think it is the math that is behind all the awkwardness in modern physics. We just need to change the unchallenged math axioms to fit the new physical reality. See my post: Are natural numbers sacred in the universe?
JohnSSM Posted January 12, 2015 Author Posted January 12, 2015 It may be unnecessary to bang one’s head over the space-time conundrum, if a different math is adopted. I think it is the math that is behind all the awkwardness in modern physics. We just need to change the unchallenged math axioms to fit the new physical reality. See my post: Are natural numbers sacred in the universe? But they are unchallenged because nothing else can explain it better...These guys cant guarantee that all the known math now can explain everything that it may not be considering, but being the best and most thorough explanation is just that...and that is what math gives us...not my thoughts, or anyone else's thoughts...but i am still williing to discuss them with you as long as you dont veer to far from what math tells us...it is fun on this side... That was my point about dark matter and dark energy in the beginning...no matter what, so far, we have this mysterious and undefined thing...aether, the cosmo constant, dark matter...it seems we can take unknowns and work them into equations and just give the unknown a new name...but aether and the cosmo constant has been disproved with better models...or math...and dark energy and dark matter have not been disproved...and are still awaiting final approval...but aether and CC are gone... It may be unnecessary to bang one’s head over the space-time conundrum, if a different math is adopted. I think it is the math that is behind all the awkwardness in modern physics. We just need to change the unchallenged math axioms to fit the new physical reality. See my post: Are natural numbers sacred in the universe? If you can look at the math of general relativity and then try to ration what it is truly explaining about our universe, then you do see this sacred relationship...because it explains what you cannot
Mordred Posted January 12, 2015 Posted January 12, 2015 Those mathematics define the stationary limit region where one can have a possible stationary observer speed of light or less. just prior to even the speed of light being caught by frame dragging.
JohnSSM Posted January 12, 2015 Author Posted January 12, 2015 Those mathematics define the stationary limit region where one can have a possible stationary observer speed of light or less. just prior to even the speed of light being caught by frame dragging. Yes,,,I still dont know all the spheres on that page...I thought "stationary limit surface" meant the surface of the mass...Ive been reading it over and over and it sinks in a bit more each time...I never could have come up with the "ergosurface" on my own...amazing
ajb Posted January 12, 2015 Posted January 12, 2015 But they are unchallenged because nothing else can explain it better... This is not a bad way to view the situation. The idea of space-time, fields, curvature etc is the best framework we have for physics, this goes beyond just general relativity. Unless someone can really come up with something different these ideas are here to stay. Even then, with some other framework you would need to have some understanding of how space-time etc appears as a limit in this other framework. Otherwise it would be very difficult to understand why these geometric notions have been so useful in physics. Not that you have really tired to challenge general relativity here, but quite often those that do look for applications in cosmology and then present a 'theory' with no mathematics. At best it could be an interpretation and worse just a random collection of physics sounding words, a bit like what you hear on Star Trek. Either way it is hard to argue against things that are not well posed. Most of what you have said falls into this category of not-well-posed. This is compounded by the use of words that have specific meaning in physics and mathematics. This makes it very hard for many of us to get what you are asking and give you a sensible answer. Anyway, you monkey comment was funny. It is true that you can get a feel for general relativity without much mathematics. The pen and balloon experiment may help you as will Einstein's trampoline. But neither of these will allow you to get a deeper understanding of general relativity (or any branch of physics), for that you need the mathematics. Exactly what and how much depends on your taste and interests, but for sure you need some. Mathematics is the language we use, while physics is the poetry.
JohnSSM Posted January 12, 2015 Author Posted January 12, 2015 This is not a bad way to view the situation. The idea of space-time, fields, curvature etc is the best framework we have for physics, this goes beyond just general relativity. Unless someone can really come up with something different these ideas are here to stay. Even then, with some other framework you would need to have some understanding of how space-time etc appears as a limit in this other framework. Otherwise it would be very difficult to understand why these geometric notions have been so useful in physics. Not that you have really tired to challenge general relativity here, but quite often those that do look for applications in cosmology and then present a 'theory' with no mathematics. At best it could be an interpretation and worse just a random collection of physics sounding words, a bit like what you hear on Star Trek. Either way it is hard to argue against things that are not well posed. Most of what you have said falls into this category of not-well-posed. This is compounded by the use of words that have specific meaning in physics and mathematics. This makes it very hard for many of us to get what you are asking and give you a sensible answer. Anyway, you monkey comment was funny. It is true that you can get a feel for general relativity without much mathematics. The pen and balloon experiment may help you as will Einstein's trampoline. But neither of these will allow you to get a deeper understanding of general relativity (or any branch of physics), for that you need the mathematics. Exactly what and how much depends on your taste and interests, but for sure you need some. Mathematics is the language we use, while physics is the poetry. Someone else is waxing poetic...i like it...well said! If only we could turn math into poetry...i could finally read it and appreciate it... I tell you what though, some of these authors Im reading right now seem to be better than others at using language to explain...and that may only be an aesthetic difference that I prefer...and thats damn close to poetry...
ajb Posted January 12, 2015 Posted January 12, 2015 If only we could turn math into poetry...i could finally read it and appreciate it... It can be, but I feel that to make mathematics really fun it should have some applications. Not that everyone will agree with that statement.
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