Space-Time?

[peter]

What is the quality of space-time that makes it different from the region of 'not space-time' within which the infinite Universe presumably sits. Come to that what is the quality that makes it different from matter. Is it just 'extension' without 'mass' [matter being extension with mass], and that 'non' region being neither extension nor mass. Has space-time energy; does it contribute to the energy total of the Universe - or is all of that tied up in the mass [I've heard of e=mc[2], but never one that says te=mc + s-t[2] [where t= total and s-t = ...you get it]]. I've heard that it 'foams' down at it's smallest level [but so does Guiness and I don't understand that either] but that that foaming is energy neutral because of a balancing act of the energy of existance against the negative energy of anti-existance, and so that doesn't really count.

Damned if I get it!

[Vraith]

What is the quality of space-time that makes it different from the region of 'not space-time' within which the infinite Universe presumably sits. Come to that what is the quality that makes it different from matter. Is it just 'extension' without 'mass' [matter being extension with mass], and that 'non' region being neither extension nor mass. Has space-time energy; does it contribute to the energy total of the Universe - or is all of that tied up in the mass [I've heard of e=mc[2], but never one that says te=mc + s-t[2] [where t= total and s-t = ...you get it]]. I've heard that it 'foams' down at it's smallest level [but so does Guiness and I don't understand that either] but that that foaming is energy neutral because of a balancing act of the energy of existance against the negative energy of anti-existance, and so that doesn't really count.

Damned if I get it!

This is a thing that, very often, especially in the middle of paragraphs by smart people talking about Reality/The Universe, I just find myself staring unfocused into space and struggling with.
What the hell IS "space?" It must be SOMETHING...it stretches, it can be flat or curved, warped [so probably woofed or wefted, too] it can apparently "be" in "directions" [and/or at sizes] we can't see.
It has to, in some way, be a different kind of thing from whatever it is expanding into, doesn't it?
And speaking of expanding---unlike anything "in" space, it can "travel" faster than light.
I could go on forever on the things we don't know, the oddities/contradictions that arise from what we seem to know.
I have this recurring thing that pops into my head in various forms that amuses me [though I don't think it is real]. One form is a banner headline out of CERN "Scientists unexpectedly discover Dimensiton!" [[the dimensiton is the fundamental particle of space, in its free/unbound state. Almost all the "time" it doesn't do anything but "be." But there is so much of it, that even those ultra-rare vibrations create/bind/adhere to do stuff...like create Strange Beauty and Charm [not to mention Top and Bottom]. Just fun, you know...my right brain tickling my left brain to make it giggle, cuz lefty is SOO tedious and dull when moping about contemplating.
You notice I left out the time part---though that is a kind of no-no, I did it on purpose. Cuz I have a notion [probably mentioned it before] that we, perhaps, are too fascinated/confused by, and focused on time. I suspect that time is like water...seems all special and unique and contrary.
But it isn't, really, once you understand hydrogen and oxygen.
Once we understand "space," we'll look at time and go "well, duh..."
[[there probably are such things as emergent properties, I'm convinced of it---unexpected things that happen when 2 things get together that are unpredictable, even in theory, from known/knowable information. The properties of water are not among those things. I suspect time is the same. Whatever it is, why it works as it does, arises directly and predictably from whatever "space" is.]]

[Hashi Lebwohl]

If you subscribe to membrane theory, then "spacetime" is what happened when several membranes collided and interacted with each other. The universe that we know sits inside a (so far) stable bubble of those membranes and, thankfully, our bubble hasn't popped yet. The outside of the bubble are the individual membranes which combined to form what we know. I cannot begin to imagine what reality is like at that surface (and I probably don't want to try, either).

Matter is compressed spacetime. You are made of the same stuff as the distance between you and the wall on the far side of the room where you sit right now.

Time moves differently in higher dimension than it does in the four we know, which is why we can get weird things like quantum-coupled photons reacting with each other at supraluminal speeds; this also explains why positrons are merely electrons moving backward through time.

[peter]

There's some pretty weird stuff going on in physics right now. Apparently there is a growing belief that the speed of light may not actually be the fixed thing that is supposed by relativity. I seem to have read [though couldn't begin to expand on it] that the quantum expansion [or is it quantum multiverse expansion] is in some ways an answer to those cosmologists who are unhappy with big-bang theory and it's demand for a 'starting-point' of everything [I read from this that there are theories out there where no 'big-bang' actually occured, but I may be wrong on this]. Lastly, and most closely related to V's post above, there is a definite movement toward the idea that either space or time is going to be demonstrated to be an emergent property of the other and that at the deeper level of quantum reality the one or the other will transpire to be illusory. Theoretical physicist Lee Smollin for example believes that it will be space that will turn out to be the looser and that time will be representative of the deeper order.

[Frostheart Grueburn]

Could you rec some books about the newest theories? It's been a while since university physics.
(I have a technical education so would appreciate something more advanced than the layman's version.)

[peter]

trust me Frosty, there are people way more qualified to answer that request than me around here, but I'm confident that a reading of David Deutch's The Begining of Infinity will blow you away. I'm currently reading How To Make a Human Being by Christopher Potter, which while not being exclusively a physics book starts with the idea of how to make a Universe and, in it's consideration of the [difficult] interface of science, philosophy and religion, does give a pretty good description of what is believed by some of the most 'out-there' physicists of the day. [It's also a very beautiful quirky book to boot.] Pysicist Michio Kaku writes some tremendous books on the far edges of physics eg Physics of the Future, and his book The Future of the Mind takes us into the realm of what the new physics will do in terms of altering the very meaning of what it means to be human.

[Vraith]

Yea, p...
I saw a reference to non-absolute light speed somewhere...
I've seen [I think we talked about briefly?] light is the "border" that pretty much only photons travel at, and for everything "normal" it's the "max," and for other things it is the "min"...the theoretically slowest speed they can approach, but never reach.
Related to that, recently someone was saying that neutrinos [or some 'flavor' of neutrino] are tachyons [time traveling particles that are one of the things above, light-speed is the minimum].

I read an excerpt of Potter's first book---I think it was his first?---remember liking his style. Maybe try the one you're in.

On time being the ground, and space emerging from it---that I don't recall ever hearing before. Seems very strange to me---which means I'm going to have to check it out. Strange is like catnip to me. .

[peter]

Hope I'm not sending you on a wild goose chase with that one V. Most of that stuff comes from Potters book but he does seem to be quoting from some pretty 'up there' physicists not least Deutsch. He also has some really bizzare stuff on mathematics like how it's possible to use numbers in mathematical calculations without even knowing what the numbers are [eg 'Grahams Number', the largest number ever used in a calculation, nothing about which is known other that it ends with a seven!]. {Graham incidentally was an ex-circus performer, not that this has any bearing on the issue }

[Vraith]

Hope I'm not sending you on a wild goose chase with that one V. Most of that stuff comes from Potters book but he does seem to be quoting from some pretty 'up there' physicists not least Deutsch. He also has some really bizzare stuff on mathematics like how it's possible to use numbers in mathematical calculations without even knowing what the numbers are [eg 'Grahams Number', the largest number ever used in a calculation, nothing about which is known other that it ends with a seven!]. {Graham incidentally was an ex-circus performer, not that this has any bearing on the issue }

Hee...check out the link below for fun with Graham's number [well...kinda fun...it gets a bit much.]
At the beginning is a link to the lead up [getting up to the number 1,000,000], if you want to limber up first.

waitbutwhy.com/2014/11/1000000-grahams-number.html

[peter]

Thats just ridiculous V. No wonder so many mathmaticians finnish up in assylums! Interesting that Graham, in his original problem seemed [to my untrained ear at least] to be wrestling with a massively more complex version of the same problem that map-makers deal with - namely what is the minnimum number of colours you need to draw a political map of the world such that no two adjacent countries share the same colour. I think it's about four or five, but can't be sure.

Just in case you never came across this book V, a guy named Alex Bellos wrote a book called Alex's Adventures In Numberland, which deals exclusively with the weird and wonderful aspects of mathematics and I thought was a ball!

[Vraith]

No wonder so many mathmaticians finnish up in assylums!

Interesting that Graham, in his original problem seemed [to my untrained ear at least] to be wrestling with a massively more complex version of the same problem that map-makers deal with - namely what is the minnimum number of colours you need to draw a political map of the world such that no two adjacent countries share the same colour.

Just in case you never came across this book V, a guy named Alex Bellos wrote a book called Alex's Adventures In Numberland, which deals exclusively with the weird and wonderful aspects of mathematics and I thought was a ball!

On the first, I won't justify it much except to say I hadn't been to sleep yet, and my last bloody mary and first cup of coffee weren't sufficiently far apart in time perhaps...but I read that as a fairly amusing juxtaposition of aesthetic proportions, folk from Finland, and butts.

On the second...I believe the starting point was the same family of problem as you say.

On the last--hadn't heard of it, looks like fun.

[peter]

Yes - there may have still been a bit of New Years Day good cheer still swilling about in that post. Gad' damn - I never did get that spellin' thing!

[Vraith]

This seems topical.
Dark energy, time, general and special relativity, the shape/size of the universe all in one.
Haven't seen the whole paper---haven't seen much of anyone weigh in on validity yet.

Einstein’s general theory of relativity indicates that time dilation in response to gravity is directional in that an object in high gravity will have slower time than an object in low gravity. In contrast, Einstein’s theory of special relativity describes reciprocal time dilation between two moving objects, such that both moving objects’ times appear to be slowed down relative to each other.

astronomynow.com/2015/01/05/dark-energy-explained-by-relativistic-time-dilation/

[peter]

Not sure I grasped all of that but very intersting never the less. Presumably being effectively able to 'do away' with dark energy would greatly simplify the model of the universe that cosmologists have to deal with. Interesting that the paper should come from the scource of a molecular biologist rather than an individual whose primary specialism is physics - wonder how well the cosmology boys will take that .

[edit; Also very interesting was the degree to which 'relativity effects' are seen in the time duration passage of GPS satellites - several seconds per day did it say! Just how fast are those things travelling?]