Phi for All Posted January 9, 2015 Posted January 9, 2015 I take lots of time to type and explain and think...I would rather have you send me private messages to a bunch of links...if everyone did the same, there would be no talking and I could just google the topic entries to find reading material... But im for more than reading material...I am here, at a forum, mostly for discussion... Don't be offended when I ignore those postings from now on...Im sorry, im not interested I those links right now... ! Moderator Note Please understand that you're not the only one following this thread. I know it's your concept, but others can learn from a transparent discussion with the experts you're engaging. Others may not wish to ignore the offered reading material, so it will continue to be made available as links in this thread. No need to respond to this in thread. Report it if you object.
ajb Posted January 9, 2015 Posted January 9, 2015 I am willing to pay someone who is willing to let me ask them some questions about GR...kinda like a tutor...am I allowed to make such offers? You can post specific questions on this forum. However, if they are very technical you may not get a great response.
JohnSSM Posted January 9, 2015 Author Posted January 9, 2015 You can post specific questions on this forum. However, if they are very technical you may not get a great response. I offer the money so that an expert would take the time to discuss things with me and not just send me links
elfmotat Posted January 9, 2015 Posted January 9, 2015 I offer the money so that an expert would take the time to discuss things with me and not just send me links I recommend purchasing an introductory GR textbook. Asking questions usually isn't the difficult part -- it's knowing which questions to ask that can be hard. A good textbook will do that for you. Otherwise you might end up wasting people's time by asking nonsensical or ill-defined questions. Schutz and Hartle, together, are probably your best bet. Schutz focuses more on the underlying math, has a wonderful section at the beginning to go over special relativity, vectors, dual vectors, tensors, etc., for people who may not be familiar with differential geometry. The first half gives you a great intuition for the notation, the basics of differential geometry, and the ideas that led to the Einstein Field Equations. The second half is about solutions to the field equations, approximation methods like linearized gravity, gravitational waves, etc. Hartle focuses mostly on solutions to the EFE's, and how to extract meaning from different metrics. My favorite book on GR is Carroll's, but it may be a bit beyond a first-time-learner's level if they aren't already somewhat familiar with the formalism. For reference texts, MTW and Wald are great. MTW goes over hundreds of topics in great detail, though it is admittedly a bit outdated. Wald is more up to date and has a very formal mathematical approach to things. If you have any specific questions, this forum can often be very helpful. There are a number of people here who are familiar with GR. For very technical questions, I might redirect you to the physics stack exchange.
Mordred Posted January 9, 2015 Posted January 9, 2015 (edited) I've read the other books except the one by Schultz. Good review on em I agree with with Elfomatat's accessment. Lecture notes by Mathius Blau is also good if you have the math skills. See my signature. Least it's free lol. I linked a free one by Caroll already on this thread Edited January 9, 2015 by Mordred
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 I recommend purchasing an introductory GR textbook. Asking questions usually isn't the difficult part -- it's knowing which questions to ask that can be hard. A good textbook will do that for you. Otherwise you might end up wasting people's time by asking nonsensical or ill-defined questions. Schutz and Hartle, together, are probably your best bet. Schutz focuses more on the underlying math, has a wonderful section at the beginning to go over special relativity, vectors, dual vectors, tensors, etc., for people who may not be familiar with differential geometry. The first half gives you a great intuition for the notation, the basics of differential geometry, and the ideas that led to the Einstein Field Equations. The second half is about solutions to the field equations, approximation methods like linearized gravity, gravitational waves, etc. Hartle focuses mostly on solutions to the EFE's, and how to extract meaning from different metrics. My favorite book on GR is Carroll's, but it may be a bit beyond a first-time-learner's level if they aren't already somewhat familiar with the formalism. For reference texts, MTW and Wald are great. MTW goes over hundreds of topics in great detail, though it is admittedly a bit outdated. Wald is more up to date and has a very formal mathematical approach to things. If you have any specific questions, this forum can often be very helpful. There are a number of people here who are familiar with GR. For very technical questions, I might redirect you to the physics stack exchange. When youre paying people, wasting time is income... I have allready started in on two books,,,either strange or mordred reccomended them... It turns out, most of the questions I have are the ones that dont have solutions or answers yet...
Mordred Posted January 10, 2015 Posted January 10, 2015 In some cases that happens. However the knowledge gained allows one to ask the same questions more accurately and concise. Without random misunderstandings interfering.
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 Nope. That is why the maths is so useful, it tells you when your intuition/guesses are wrong: http://en.wikipedia.org/wiki/Milne_model http://en.wikipedia.org/wiki/Kasner_metric http://en.wikipedia.org/wiki/Taub%E2%80%93NUT_space I do understand that these foljks used GR to figure these solutions...the question` then becomes, could the circumstance of their presuppositions ever exist? Because a mathemathical solution is found doesnt really mean that it could happen...it means if it did happen, they can predict the outcome...that may be kinda shakey to some... Is geometry the cause or effect...i say its an effect of something else, and in this case, not space foam. Even in GR ,it seems that the geometry is an effect of vectors...those vectors originate in mass and energy...to me, its like saying, without any motion of any sort from a mass, would spacetime be curved? Are there vector without relative motions? Maybe its more important to decide if it is possible before doing an equations...even if your equations could give you an answer... i suppose im ever stuck in a world of imagination...all these things I talk about seem to become questions of philosophy I guess.... In some cases that happens. However the knowledge gained allows one to ask the same questions more accurately and concise. Without random misunderstandings interfering. I know...but i can learn form random misunderstandings...and I do...this is why i offered to pay someone...i know its a pain in their butt... Hey strange, can you offer some insight on this statement? "I think his point really becomes that the geometry is created by the vectors and tensors of the particles that enter spacetime...they have motions and energies and the geometry created by THEM, is that which then effects THEM, is caused by THEIR influence...individually and as a group"
Mordred Posted January 10, 2015 Posted January 10, 2015 (edited) We don't necessarily expect to find these toy universes. They are used for a specific function. Lets run an example. "What would our universe look like with no cosmological constant?" How do we figure this out. Well we can take an equation that has been well tested or several equations we know work. Then we crunch the numbers to see what happens. The purpose is to allow one to fully understand what one specific influence changes. One of the best cosmology textbooks I ever read does this in painstakingly detail. She starts with explaining how the FLRW metric works. Then she describes all the single component universes. ( matter only,radiation only,Lambda only etc,) Then she does multi universe combinations. Finally arriving at our current universe. Due to that detail one truly can understand the term universe geometry and the relation to the ideal gas laws. We look into the universe it certainly doesn't look flat. In fact the observable universe looks round. So why does science say it's flat? The answer is the term flat is an energy density distribution term. Key note the FLRW metric is compatible with the Einstein field equations. By the way the textbook is Barbera Rydens "Introductory to Cosmology" So no we don't expect to find a Milne universe. Note in the case of the Milne universe Milne was unaware of GR and SR as noted in the wiki page I've never heard of the other two models Strange linked. There is another toy model universe that's handy to understand De-Sitter/anti-Desitter. http://en.m.wikipedia.org/wiki/De_Sitter_space I'm still hinting by the way. second clue look at equations of state cosmology google that term. Then look at the Einstein field equations and the FLRW metric. You should note all three involve the ideal gas laws. Then realize that so does GUT. You asked for a direction of study start with the gas laws It will make the EFE and FLRW metric easier to relate to. Ps don't forget the math Here is a universe geometry article I wrote http://cosmology101.wikidot.com/universe-geometry Page 2 http://cosmology101.wikidot.com/geometry-flrw-metric/ Edited January 10, 2015 by Mordred
elfmotat Posted January 10, 2015 Posted January 10, 2015 When youre paying people, wasting time is income... Frustrating income I have allready started in on two books,,,either strange or mordred reccomended them... It turns out, most of the questions I have are the ones that dont have solutions or answers yet... That's all well and good. It's good to be intrigued by the unknown. Unfortunately, knowing how to push the boundaries of the unknown takes years and years of learning and training. I do understand that these foljks used GR to figure these solutions...the question` then becomes, could the circumstance of their presuppositions ever exist? Because a mathemathical solution is found doesnt really mean that it could happen...it means if it did happen, they can predict the outcome...that may be kinda shakey to some... It's based on General Relativity, which is so far the best, most accurate theory of gravity we have. Extrapolating our theories to the unknown is part of physics. You take what's known, extrapolate, then compare to reality. A good approximation of empty space is intergalactic space, which is indeed approximately Minkowskian. Is geometry the cause or effect...i say its an effect of something else, and in this case, not space foam. This is what I meant by ill-defined nonsensical questions. I don't know how to answer because it's not really a meaningful question. Even in GR ,it seems that the geometry is an effect of vectors... I don't know what this is supposed to mean either. Geometry is geometry, not vectors. Vectors can be useful mathematical objects, but they certainly don't define the geometry of spacetime. those vectors originate in mass and energy... This also makes little sense to me. to me, its like saying, without any motion of any sort from a mass, would spacetime be curved? This doesn't make any sense either. At least, it's a poorly formed question. No motion according to who? Why would there need to be motion for curvature? Are there vector without relative motions? Vectors are mathematical objects. There are types of vectors that have absolutely nothing to do with motion, relativity, or even physics. Maybe its more important to decide if it is possible before doing an equations...even if your equations could give you an answer... I can't follow this either. i suppose im ever stuck in a world of imagination...all these things I talk about seem to become questions of philosophy I guess.... That's kind of a problem if you ever want to actually learn any physics. Physics is not philosophy. Physics is mathematical models of reality, which can be falsified by experiment. "I think his point really becomes that the geometry is created by the vectors and tensors of the particles that enter spacetime...they have motions and energies and the geometry created by THEM, is that which then effects THEM, is caused by THEIR influence...individually and as a group" I don't really know if I like that description. It seems to imply that energy-momentum causes spacetime curvature, which is simply not true by any common understanding. Einsteinian curvature and energy-momentum are equivalent, i.e. if you have one you have the other. Asking which causes which is sort of nonsensical. They both cause and effect each other. The geometry effects the matter, and the matter effects the geometry.
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 (edited) Mordred, I beileve it was you, urging to me that I did not need the gluon field to understand GR geometry...or the impetus of why...i had to really consider it all...and you were totally right...I think...What Im trying to establish in my head is that mass effects spacetime, due to its own propeties (vector and energy), and from the vectors of other mass in its relative vicinity...Its tied to another point that was discussed...If you brought a magnet into a room with no EMF, then the only EMF in the room would be sourced by the magnet...when you heat the magnet, it loses it's magnetic properties and the field IT created is now gone...If we couldnt get a room free of EMF, could we at least distinguish the EMF created by the magnet itself to run the same experiment?...I know heat would not disable the entire EMF from the room, but it would disable the EMF created by the magnet...Replace EMF with space-time, and replace Magnet with mass...then youd replace heat with gravity...If you brought a mass into a room with no space_time, then the only space-time in the room would be sourced by the mass...when you add gravity to the mass, it loses it's mass-like properties and the field (space-time) it created is now gone...If we couldnt get a room free of gravity, could we at least distinguish the gravity created by our mass from the rest of gravity created from other mass to run the same experiment?...I know gravity would not disable the entire space-time from the room, but it would disable the space-time created by the mass we entered with...Now just replace gravity with compression...You can also replace space-time with geomtery or even GR Edited January 10, 2015 by JohnSSM
Mordred Posted January 10, 2015 Posted January 10, 2015 That is if you truly want to understand what drives space time expansion and contraction. [latex]Pv=nRT[/latex]
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 So basically, I believe black holes are examples of where intense gravity disables GR geometry and the grid it creates at the event horizon...no grid means no space and no time...
Mordred Posted January 10, 2015 Posted January 10, 2015 All the forces and the standard model of particles are involved in the thermodynamics of our universe. Each particle species influences temperature and pressure. Each interaction does the same. In the FLRW metric curvature is the relation of positive pressure and the negative pressure contributors to each other. This defines how the universe expands or contracts. It also defines the path of light as it travels to us. A flat universe light is straight. In a curved universe it isn't. Read the two links I wrote for more detail. There is your space time geometry at the universal scale.
elfmotat Posted January 10, 2015 Posted January 10, 2015 (edited) Mordred, I beileve it was you, urging to me that I did not need the gluon field to understand GR geometry...or the impetus of why...i had to really consider it all...and you were totally right...I think... What Im trying to establish in my head is that mass effects spacetime, due to its own propeties (vector and energy), and from the vectors of other mass in its relative vicinity... Its tied to another point that was discussed...If you brought a magnet into a room with no EMF, then the only EMF in the room would be sourced by the magnet...when you heat the magnet, it loses it's magnetic properties and the field IT created is now gone...If we couldnt get a room free of EMF, could we at least distinguish the EMF created by the magnet itself to run the same experiment?...I know heat would not disable the entire EMF from the room, but it would disable the EMF created by the magnet... Replace EMF with space-time, and replace Magnet with mass...then youd replace heat with gravity... If you brought a mass into a room with no space_time, then the only space-time in the room would be sourced by the mass...when you add gravity to the mass, it loses it's mass-like properties and the field (space-time) it created is now gone...If we couldnt get a room free of gravity, could we at least distinguish the gravity created by our mass from the rest of gravity created from other mass to run the same experiment?...I know gravity would not disable the entire space-time from the room, but it would disable the space-time created by the mass we entered with... Now just replace gravity with compression... 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. So basically, I believe black holes are examples of where intense gravity disables GR geometry and the grid it creates at the event horizon...no grid means no space and no time... 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? Edited January 10, 2015 by elfmotat
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 That is if you truly want to understand what drives space time expansion and contraction. [latex]Pv=nRT[/latex] Ha...you fooled me by giving it another name...so I gave in and read it...aside from the equations of course... It was all very intuitive to me..Im pretty sure I could have written most of it myself, aside from the equations...volume, amount, pressure and temperature are really intuitive at this point, for me... Show me some proof of spacetime at the event horizon...there's an article Im requesting.
Mordred Posted January 10, 2015 Posted January 10, 2015 So basically, I believe black holes are examples of where intense gravity disables GR geometry and the grid it creates at the event horizon...no grid means no space and no time... this is where the term singularity comes into play. Aka infinitely dense of pointlike volume. Careful on the time term and the observer. A theoretical observer wouldn't notice a change in time inside the EH by his own clock
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 (edited) I can show you proof that theres no EMF at the end of a hot magnet. Mordred, i would try speaking to me in the terms of the ideas that were presented... I know its hard...and maybe what im asking is out of line... We can do it one point at a time...If I bring a magnet into a room, can i distinguish the EMF from that magnet, from the emf that was allready present? this is where the term singularity comes into play. Aka infinitely dense of pointlike volume. Careful on the time term and the observer. A theoretical observer wouldn't notice a change in time inside the EH by his own clock Infinitely dense can go no further than to disable space-time...what would more density do? disable it more after its allready disabled? infinite does not have to be a number...it is a concept as well We dont need infinite heat to disable the magnet... Edited January 10, 2015 by JohnSSM
Mordred Posted January 10, 2015 Posted January 10, 2015 I can show you proof that theres no EMF at the end of a hot magnet. Mordred, i would try speaking to me in the terms of the ideas that were presented... I know its hard...and maybe what im asking is out of line... We can do it one point at a time... If I bring a magnet into a room, can i distinguish the EMF from that magnet, from the emf that was allready present? Infinitely dense can go no further than to disable space-time...what would more density do? disable it more after its allready disabled? Here is a simple experiment on magnets. Get some iron filings and a sheet of paper. Place magnet under sheet of paper then sprinkle the iron filings onto the sheet. Map the field lines. Then do the same for your heated magnet. ( don't start a fire lol might want some space.) Repeat the experiment.
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 We know that stuffing more stuff increases the energy of the stuff and increases the curvature of spacetime in it's favor...stuffing in more stuff gives more gravity...gravity is the loss of time and space (dilation)...you get it stuffed in dense enough and you get a black hole...it is a point of density...not mass, or size, but energy per space-time..right? Here is a simple experiment on magnets. Get some iron filings and a sheet of paper. Place magnet under sheet of paper then sprinkle the iron filings onto the sheet. Map the field lines. Then do the same for your heated magnet. ( don't start a fire lol might want some space.) Repeat the experiment. I allready know for certain what heat does to magnetic fields
Mordred Posted January 10, 2015 Posted January 10, 2015 Now think about the movement of particles within the magnet. Then think of why an electric current induces magnetism. When you hear a material what happens? Remember a magnet is an average of particle polarity
JohnSSM Posted January 10, 2015 Author Posted January 10, 2015 Its excites the electrons and they no longer distribute themselves by magnetic position...the heat forces them into different random positions and the magnetism goes away..along with the field it was creating
Mordred Posted January 10, 2015 Posted January 10, 2015 So all your doing is causing kinetic movement of the particles interfering with their polarity average
Mordred Posted January 10, 2015 Posted January 10, 2015 Its excites the electrons and they no longer distribute themselves by magnetic position...the heat forces them into different random positions and the magnetism goes away..along with the field it was creating Correct
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now