Mordred Posted July 9, 2017 Author Posted July 9, 2017 (edited) Anytime you are able to assign more than one geometric location. (object, event, coordinate) You can treat any set of values to the coordinates under a field treatment. That is really the only requirenent to have a field. A field is any collection of values described via coordinate/geometry. Glad you enjoyed this thread by the way. Space is just volume, fields are not required to have space. However once you have volume you can describe that volume as a field. A field is an abstract device that abstract device allows us to "map" variations. The term spacetime is a field treatment. Its one describing changes with our 3d volume by adding time as a vector to track different rates of information exchange between coordinates or events. Edited July 9, 2017 by Mordred
StringJunky Posted July 9, 2017 Posted July 9, 2017 Questions Does space only exist because it is full of fields. With no fields there is no space time. Space and time being variables to give the distance between fields, which if they didnt exist space time would not exist. How can space be curved without fields, how can a volume exist without a field or reference point to measure from. Can an infinte space full of fields of one form or another exist at the same time as an empty space full of nothing, would the emopty space be zero volume. This is how I think. The existence of space - which is just volume - is dependent on the existence of fields. On that line of thinking, empty spaces full of nothing (?) can''t exist.
Handy andy Posted July 9, 2017 Posted July 9, 2017 Thankyou for the answer, I think what was driving at is. The expansion of space under the big bang theory, was filled from the outset by fields of one form or another. Did the fields themselves create the space they occupy. Can space exist without fields. Space with no fields in cant exist. Sorry cross posted thanks for the answer
Mordred Posted July 9, 2017 Author Posted July 9, 2017 Thankyou for the answer, I think what was driving at is. The expansion of space under the big bang theory, was filled from the outset by fields of one form or another. Did the fields themselves create the space they occupy. Can space exist without fields. Space with no fields in cant exist. Sorry cross posted thanks for the answer Understood on the cross post. Glad to help. (I did add an edit on above on x post)
StringJunky Posted July 9, 2017 Posted July 9, 2017 Space is just volume, fields are not required to have space. However once you have volume you can describe that volume as a field. A field is an abstract device that abstract device allows us to "map" variations. But - I assert - fields permeate the whole universe; gravity/spacetime extends everywhere.
dimreepr Posted July 9, 2017 Posted July 9, 2017 Thankyou for the answer, I think what was driving at is. The expansion of space under the big bang theory, was filled from the outset by fields of one form or another. Did the fields themselves create the space they occupy. Can space exist without fields. They are the space they occupy
Mordred Posted July 9, 2017 Author Posted July 9, 2017 (edited) But - I assert - fields permeate the whole universe; gravity/spacetime extends everywhere. Yes but a further caveat fields can be smaller system states. ie the region of measurable influence. So the strong force from a single particle does not extend to infinity as per electromagnetic or gravity. In this sense we can confine the strong force from each particle by measurable "action" which under QFT is your operators describing system state wavefunctions under field treatments. This is where the distictions "local and global becomes defined Edited July 9, 2017 by Mordred
Roger Dynamic Motion Posted July 9, 2017 Posted July 9, 2017 This is how I think. The existence of space - which is just volume - is dependent on the existence of fields. On that line of thinking, empty spaces full of nothing (?) can''t exist.To me, when I hear or read the word nothing ; i cannot think other of an other particle that i have called Nothing..and it's a ''Cube''. The reason Why? is that ,when in my head i shrink the 8 corners back to the center of the cube i do not see the Cube any more So! what if empty space, we so call, was replaced by cubes that cannot be detected and nor seen .
Handy andy Posted July 9, 2017 Posted July 9, 2017 "Space is just volume, fields are not required to have space" A molecule takes up space, around the molecule is a gravitational field which occupies space. Is the expansion of the space we percieve not governed by fields filling it. Galaxies free falling away from us at 3c on the edge of an expanding universe are being driven by the gravitational field which is driving them away from us.
Mordred Posted July 9, 2017 Author Posted July 9, 2017 (edited) "Space is just volume, fields are not required to have space" A molecule takes up space, around the molecule is a gravitational field which occupies space. Is the expansion of the space we percieve not governed by fields filling it. Galaxies free falling away from us at 3c on the edge of an expanding universe are being driven by the gravitational field which is driving them away from us. Yes expansion is governed by fields. a field can be described as a distribution of any arbitrary values. So one cannot state volume causes fields. The volume simply defines the volume of whatever values the field is describing. Edited July 9, 2017 by Mordred 1
StringJunky Posted July 9, 2017 Posted July 9, 2017 (edited) To me, when I hear or read the word nothing ; i cannot think other of an other particle that i have called Nothing..and it's a ''Cube''. The reason Why? is that ,when in my head i shrink the 8 corners back to the center of the cube i do not see the Cube any more So! what if empty space, we so call, was replaced by cubes that cannot be detected and nor seen . Up to now, space has not been quantised so we can only assume it's volume. Scientists did an experiment that went on the basis that if space was granular, red frequencies would travel faster than blue ones since their velocity might be impeded less because of the granularity. The distances required went to billions of light years but both ends of the spectrum arrived, effectively, at the same time. Edited July 9, 2017 by StringJunky
Mordred Posted July 9, 2017 Author Posted July 9, 2017 (edited) Simply put you cannot have a field if you have no volume. Or technically volume or area for 2d fields Edited July 9, 2017 by Mordred
Itoero Posted July 9, 2017 Posted July 9, 2017 Anytime you are able to assign more than one geometric location. (object, event, coordinate) You can treat any set of values to the coordinates under a field treatment. That is really the only requirenent to have a field. A field is any collection of values described via coordinate/geometry. Glad you enjoyed this thread by the way. Space is just volume, fields are not required to have space The idea that values are not required to have space, is that because of Bell's theorem?
Mordred Posted July 9, 2017 Author Posted July 9, 2017 (edited) I misapplied that last statement you must have volume or area to have a geometry descibed as a field. Thanks for the catch Didn't realize I mistyped that last sentence. Bells locality to nonlocality is certainly defined under fields however. In order to understand those two terms you have to examine how local is defined as a field. (local) is always a boundary confined field. Local fields can be embedded onto our arbitrary global fields. Edited July 9, 2017 by Mordred
StringJunky Posted July 9, 2017 Posted July 9, 2017 Yes but a further caveat fields can be smaller system states. ie the region of measurable influence. So the strong force from a single particle does not extend to infinity as per electromagnetic or gravity. In this sense we can confine the strong force from each particle by measurable "action" which under QFT is your operators describing system state wavefunctions under field treatments. This is where the distictions "local and global becomes defined Yes, I understand that not all extend, potentially, infinitely.
Mordred Posted July 9, 2017 Author Posted July 9, 2017 I knew you did but the opportunity to define local and global fields was presented. So I took advantage of it for other readers.
StringJunky Posted July 9, 2017 Posted July 9, 2017 I knew you did but the opportunity to define local and global fields was presented. So I took advantage of it for other readers. It's all good. You do a fine job introducing people to the idea of fields in an accessible way.
Roger Dynamic Motion Posted July 9, 2017 Posted July 9, 2017 Simply put you cannot have a field if you have no volume. Or technically volume or area for 2d fieldsBut..Volume require boundary. So what is boundary ? is it a time limit?... containing Energy ? and if so matter must be a part of it .
StringJunky Posted July 9, 2017 Posted July 9, 2017 (edited) But..Volume require boundary. So what is boundary ? is it a time limit?... containing Energy ? and if so matter must be a part of it . Volume is defined by whatever occupies it. Whatever occupies it defines the boundary. It is a parameter and does not exist by itself. Edited July 9, 2017 by StringJunky
Mordred Posted July 9, 2017 Author Posted July 9, 2017 (edited) Thanks glad to help. The reason I can do that is that I spent years understanding field treatments. Prior to attempting to simplify it for others. For example I am still trying to improve my understanding of this 1 article after 5 years reading it over and over again and of course applying the mathematics "Fields" - A free lengthy technical training manual on classical and quantum fields https://arxiv.org/abs/hep-th/9912205 Edited July 9, 2017 by Mordred
Roger Dynamic Motion Posted July 9, 2017 Posted July 9, 2017 (edited) Volume is defined by whatever occupies it. Whatever occupies it defines the boundary.Volume, cant be empty space !/ can it ? Edited July 9, 2017 by Roger Dynamic Motion
Mordred Posted July 9, 2017 Author Posted July 9, 2017 (edited) terms like empty or nothing doesn't really exist in physics. You have a volume, you can assign coordinates or events with a value even if the value is zero. So now it has a field within that volume. A common term used being vacuum. Which quite frankly is falling out of favor to the term "potential " Vacuum causes to much misunderstandings. Edited July 9, 2017 by Mordred
StringJunky Posted July 9, 2017 Posted July 9, 2017 (edited) Thanks glad to help. The reason I can do that is that I spent years understanding field treatments. Prior to attempting to simplify it for others. For example I am still trying to improve my understanding of this 1 article after 5 years reading it over and over again and of course applying the mathematics "Fields" - A free lengthy technical training manual on classical and quantum fields https://arxiv.org/abs/hep-th/9912205 Perhaps you might write something in durable form, some time, so that others may appreciate your clarity. All other other treatments of this subject I've seen require quite extensive prior knowledge. You and Sean Carroll's video have made it a lot easier for us neophytes. I would call it "The Neophytes Guide to Fields". Put me down for a copy. Volume, cant be empty space !/ can it ? Volume with nothing in it is nothing. It is defined by what's in it or the space it occupies. You can't have 'length' without something having length. It's a property of things. 'Space' has something in it, be it only fields. Edited July 9, 2017 by StringJunky
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