What is "spacetime" really?

[modest]

Time can be positive or negative - you can look forwards and backwards in that dimension

I'm not so sure. Try as I might, I've never been able to see tomorrow.

 

Also, they tell me I can see yesterday, but I'm not so convinced of that either. Put a videotape in front of me and show me a tape of yesterday and I'm more inclined to think I'm looking at today's video rather than actually seeing yesterday.

 

If I could see yesterday then I could change it—and that's another thing I've met with some difficulty. You can't change the past... oh, sure, you can photoshop the photo or edit the video, but that's no more changing the past than watching the video is viewing the past. The video exists today. The light from the distant star reaches me today.

 

~modest

 

Well, what if there is no tomorrow? There wasn't one today. :phones:

[Boof-head]

Well, maybe you can't actually see as far as you think; maybe you can't see yesterday or even the last few seconds.

Maybe the time-sign is zero and not minus; so only "now" exists.

But then you have to explain where you get this "yesterday" from, or even can conjecture about "tomorrow" or "the next instant". Perhaps you also are labouring under the illusion that you can "remember" yesterday, or somesuch imaginary "time".

[lawcat]

There is no doubt that we can see past. We see distant stars, as they were long ago. Therefore, time has a negative for sure, and that implies positive as well.

[modest]

We see distant stars, as they were long ago.

 

No doubt things from the past affect today. The photon which my eye absorbs today originated long long ago in a galaxy far far away. Nevertheless, the photon exists today. It interacts with me today. I'm seeing the results of the past... not necessarily seeing the past itself. Is there a distinction? :phones:

 

~modest

[lawcat]

No doubt things from the past affect today. The photon which my eye absorbs today originated long long ago in a galaxy far far away. Nevertheless, the photon exists today. It interacts with me today. I'm seeing the results of the past... not necessarily seeing the past itself. Is there a distinction? :phones:

 

~modest

 

I would say not; there is no difference; but, only photon can tell. (No doubt, we can not move back and forth--I will not argue against that position in your previous post; but, there must be + and - in time).

[Boof-head]

If you're still with the geometry here, it's the same as in Hawking's popular books; it looks like a curve with a cone on, or touching at it's apex a point on this curve.

 

The curve represents an external view (from the 5th dimension) of the time-direction's evolution on a 4-dimensional manifold, at the apex of a null-cone. A cone is curved in 3 dimensions; this curvature is the direction, along the time curve at the apex, or: "the curvature of 3-dimensions lives at the time-axis"; thus, 4-dimensional spacetime, with curvature.

 

And a color-map, to go.

 

If you make a deep cut in a cone, from the perimeter to the apex in a line (which is nice and straight) you can unroll the cone; this is removing a one-dimensional manifold from the surface, or puncturing (with a set of linear points) the cone.

 

Losing a dimension or transforming a cone into a sheet this way yields a wedge-shaped polygonal shape (pie-slice) - the curvature is now 'in' the perimeter. The straight edges are null-curve 'edges' of the removed null-curve from the rolled cone; unrolling it 'finds' the perimeter's circular arc in two dimensions of space. It represents something called a perimetric region's arclength. The region is the chord - another section or cut - such that the wedge becomes a triangle. The tangent space is 'in' the perimetric region, and the direction of time is an angle at the vertex.

 

Einstein's Lorentz formulation punctures Minkowski space; it finds null-geodesics so that 4-dimensional spacetime 'folds' into 2-dimensions - circular 'wedge' derivatives as circular functions of the time direction as an angle, [math] \theta [/math]

[Pyrotex]

There is no doubt that we can see past. We see distant stars, as they were long ago. Therefore, time has a negative for sure, and that implies positive as well.

au' contraire, mon ami

 

The use of "negative" to refer to distances of time in the past is merely a semantic convention. It is a totally arbitrary application of the negative/positive paradigm that works so well with numbers. Indeed, from this convention we also derive the assumption that therefore there "must be" positive durations into the future and that therefore, it must have some reality as does the past. IMHO, none of this is true.

 

The only "events" that have any reality to speak of are those in the past, up to and maybe including the present. The only "real" sense with which we can discuss time, is to treat time as the (non-negative) "distance" between any two events, as measured by an observer.

 

Kind of like Ben Franklin arbitrarily assigning "negative" and "positive" to the two types of electric charge that he found in his experiments. Turns out, he got the words backwards! The presence of excess electrons, he called a negative charge; the deficit or absence of electrons, he called a positive charge. And now it's too late to change!

[Boof-head]

Here's a quaternionic question for the thinkers: in what sense is a sectioned 'equicolored' cube which is deeply cut, hypercubical? How many dimensions does it have, and is it a polytope?

What about a sphere, is coloring a sphere - the side you can see - giving it another dimension, and how deeply can you cut a sphere?

[maddog]

Originally Posted by Boof-head

Time can be positive or negative - you can look forwards and backwards in that dimension

I'm not so sure. Try as I might, I've never been able to see tomorrow.

 

Also, they tell me I can see yesterday, but I'm not so convinced of that either. Put a videotape in front of me and show me a tape of yesterday and I'm more inclined to think I'm looking at today's video rather than actually seeing yesterday.

 

If I could see yesterday then I could change it—and that's another thing I've met with some difficulty. You can't change the past... oh, sure, you can photoshop the photo or edit the video, but that's no more changing the past than watching the video is viewing the past. The video exists today. The light from the distant star reaches me today.

 

~modest

 

Well, what if there is no tomorrow? There wasn't one today. :phones:

Modest,

 

I think he is referring to the Physics POV (Point-of-View) that in any system, time

can be view as going in either direction. The orientation does not matter to the

system (the Model -- Not -- the Something). This is only referring to the Representation

and Not Reality (at least I think that was what Boof-Head meant).

 

In addition is another way of thinking of the "now" is this:

 

Now is fleeting. The perceived "now" is already "then". For any event to communicate

to your brain will take some time (even for the photons of light to travel to your eyes

or the sound to travel to your ears). Added to that is the neuronal pathways, the signal

must travel to the occipital part of your brain before you are even "aware" of said event. So Now is Not Just Now.... Ohhhmmmmmm......................

It is instead Now - Now - Now - Now - ............................ ad infinatum.

So Michael when he "thinks" Now as being the instant (even for him) it can only the

concept of "Now" that is in his head (or any of us). An "Idealized" "Now", Not "NOW".

 

maddog

 

ps: You can even in an "Idealized" manner have that "now" the same "Now" throughout

the Universe, since it is a "now" as a concept of "now". An Actual Now, would require

an independent Observer to be vindicated. It is like a Defined Class in C++ and an

Instanciation of the Class which makes it exist. The concept is Not the "thing".

[maddog]

Here's a quaternionic question for the thinkers: in what sense is a sectioned 'equicolored' cube which is deeply cut, hypercubical? How many dimensions does it have, and is it a polytope?

What about a sphere, is coloring a sphere - the side you can see - giving it another dimension, and how deeply can you cut a sphere?

As for being a Polytope, I would say yes, though you hadn't specified how many dimensions was

this hypercube ? Four or more ? Beyond four and seems for n dimensions of original,

the cut could have upto n-1. That would seem to imply it was a Polytope.

Were we in Real space or Quaternionic space ? If Real then n = 4. If Q then n is unspecified.

 

maddog

[Boof-head]

Check this out: Hypercubic honeycomb - Wikipedia, the free encyclopedia

 

 

A bicolor cubic honeycomb. The colors represent The two integer classes in X, positive and negative time; space is 'suspended' inside the structure, with a null-point tangent to the surface vectors. It's the imaginary result of the certainty that time is negative in the initial state, if it deforms the "time surface" there is a flow, or Lagrangian.

This is 'on' the perimeter of our positive lightcone - the space is real, so we have to expand something - the null-space.

 

P.S. this might get a little abstract. It involves topology and some set theory I ain't so hot with; but we can do an in-principle representation, invent things to some extent. I mean, math is just algebra and it's algorithmic, this is kind of obvious in classification formalism and classes. Wiki-ism is good at classifying

[Boof-head]

Before getting any further (if possible) with the day-trip here, I'd like to introduce a few, I suppose, personal and hopefully general ideas, about philosophy and about "science", and where they meet, at least in my frame.

 

I've had 'discussions' with various other sciencey types over the last couple of years, on web sites such as this. It's been a bit of a mixed bag; often abuse of notation -type objections get posted at your ideas, this appears to be true for most lay-people who "have a go" at say, cosmology or quantum 'sciences' which are big subjects.

 

Actually I guess they are the biggest subjects, since we need explanations - we have a lot of questions and the more we answer the questions we have, the more surprises turn up (such as the fractional QHE, the Aharonov-Bohm effect, the ability to use entangled 'dark' photons to measure real objects without 'interacting' with them in any classical sense), stuff that Tim the Tool-Man has only one default response to - bewilderment or at least, these phenomena are both puzzling - in light of our "classical" grasp of reality, and also happening right in front of us.

 

We need "quantum specs" to look into these spaces - there aren't any strange glowing auras to tell us "quantum process is occuring now", no little green men to clue us in.

 

We are on our own here, individually and collectively, and "the universe is weird"; how weird? Is it weirder than we already think, can it get stranger?

 

Oh yeah.

 

 

So we need "strange' notation - we need to classify and categorize the languages we use, to describe these things logically and consistently; hence QM, Anti-deSitter space, advanced topology and group theory, yada yada.

 

I've been compiling a personal list of languages for a while now (I may have mentioned this), I have some understanding of linguistics (undergrad), Chomsky, deep-structure diagrams; I've got OO and list-based (Lisp, etc), and the procedural/functional paradigms of language design "in my noggin" - I've studied these formally and passed a few academic tests.

 

However I personally don't know very much; in the light of just, say, mathematical languages I have limited skills - but I know I know a few, and I know I can get the hang of a 'new' kind of language fairly easily (maybe it's some kind of ability I have, so, yippee for me), languages, to me, have certain colors, not just sounds.

 

I believe there is a language, not posable in any symbology (i.e., not writable) that I and every one else is 'listening' to every moment of existence. It doesn't consist of words as such, more things like stanzas and ongoing themes, it's more, let's say, "musical" fundamentally.

 

Here's a few notes I've collected that might help align, in a declarative fashion, where my language paradigm is at, so let's get it on.

 

Quantum Probability

 

* QM is not a set of physical theories of forces, or a geometry of quantum objects. Is a variant of classical probability theory - Copenhagen Interpretation.

 

* Matrix mechanics of QP is usually defined, with vectors or pure states and is a probability measure/interpretation.

 

* Wave mechanical interpretation of QM is special case of pure-state matrix mechanics

 

* Category theory is abstract, a measure-space. this is a natural model for empirical physical system with random variables (in it)

 

* Stochastic maps are actions in or on such systems. These actions are allowed classically; state-space is tensor products

 

* Cartesian products of measure-spaces are 'in-spirit' tensor products; these carry joint states of 2 or more separate probabilities (independence / certainty relation)

 

Spin, in QM is a no-brainer; you have left and right handedness which are also encoded in spin; therefore, since you are "handed", you have spin.

A 'particle' spinning on an axis, like a top does, can only spin to the left or right; visualizing it is easy, if you consider a spinning weight on a string - it spins left or right handedly (or as we say, in a clockwise/anticlockwise fashion).

Using your right hand rule, and your right hand, you can align this spin-direction with the orientation of your thumb; using your left hand orients the anti-spin direction.

 

Spin is spin (classically), or 'self' angular momentum; QM spin isn't classical (it's part of a particle's matter-wave), but evolves classically in measure-spaces.

[Essay]

...it can only the concept of "Now" that is in his head (or any of us). An "Idealized" "Now", Not "NOW".

 

maddog

"NOW" would be "just then."

 

So to paraphrase our host:

The simple truth is that "it" is always, perpetually, ongoing, everywhere, eternally--Just Then.

 

~ :)

[Essay]

Boofy, I wholeheartedly agree.

That's why I like the metaphor of the Spaghetti Monster--with room in its GUT for new observations, discoveries, and ideas--Flying down the throat of the Big Blackhole; the BB-FSM. Carry on ~ :)

 

see below

Before getting any further (if possible) with the day-trip here, I'd like to introduce a few, I suppose, personal and hopefully general ideas, about philosophy and about "science", and where they meet, at least in my frame.

 

I've had 'discussions' with various other sciencey types over the last couple of years, on web sites such as this. It's been a bit of a mixed bag; often abuse of notation -type objections get posted at your ideas, this appears to be true for most lay-people who "have a go" at say, cosmology or quantum 'sciences' which are big subjects.

 

Actually I guess they are the biggest subjects, since we need explanations - we have a lot of questions and the more we answer the questions we have, the more surprises turn up (such as the fractional QHE, the Aharonov-Bohm effect, the ability to use entangled 'dark' photons to measure real objects without 'interacting' with them in any classical sense), stuff that Tim the Tool-Man has only one default response to - bewiderment or at least, these phenomena are both puzzling - in light of our "classical" grasp of reality, and also happening right in front of us.

 

We need "quantum specs" to look into these spaces - there aren't any strange glowing auras to tell us "quantum process is occuring now", no little green men to clue us in.

 

We are on our own here, individually and collectively, and "the universe is weird"; how weird? Is it weirder than we already think, can it get stranger?

 

Oh yeah.

 

 

So we need "strange' notation - we need to classify and categorize the languages we use, to describe these things logically and consistently; hence QM, Anti-deSitter space, advanced topology and group theory, yada yada.

 

I've been compiling a personal list of languages for a while now (I may have mentioned this), I have some understanding of linguistics (undergrad), Chomsky, deep-structure diagrams; I've got OO and list-based (Lisp, etc), and the procedural/functional paradigms of language design "in my noggin" - I've studied these formally and passed a few academic tests.

 

However I personally don't know very much; in the light of just, say, mathematical languages I have limited skills - but I know I know a few, and I know I can get the hang of a 'new' kind of language fairly easily (maybe it's some kind of ability I have, so, yippee for me), languages, to me, have certain colors, not just sounds.

 

I believe there is a language, not posable in any symbology (i.e., not writable) that I and every one else is 'listening' to every moment of existence. It doesn't consist of words as such, more things like stanzas and ongoing themes, it's more, let's say, "musical" fundamentally.

 

Here's a few notes I've collected that might help align, in a declarative fashion, where my language paradigm is at, so let's get it on.

 

Quantum Probability

 

* QM is not a set of physical theories of forces, or a geometry of quantum objects. Is a variant of classical probability theory - Copenhagen Interpretation.

 

* Matrix mechanincs of QP is usually defined, with vectors or pure states and is a probability measure/interpretation.

 

* Wave mechanical interpretation of QM is special case of pure-state matrix mechanics

 

* Category theory is abstract, a measure-space. this is a natural model for empirical physical system with random variables (in it)

 

* Stochastic maps are actions in or on such systems. These actions are allowed classically; state-space is tensor products

 

* Cartesian products of measure-spaces are 'in-spirit' tensor products; these carry joint states of 2 or more separate probabilities (independence / certainty relation)

 

Spin, in QM is a no-brainer; you have left and right handedness which are also encoded in spin; therefore, since you are "handed", you have spin.

A 'particle' spinning on an axis, like a top does, can only spin to the left or right; visualizing it is easy, if you consider a spinning weight on a string - it spins left or right handedly (or as we say, in a clockwise/anticlockwise fashion).

Using your right hand rule, and your right hand, you can align this spin-direction with the orientation of your thumb; using your left hand orients the anti-spin direction.

 

Spin is spin (classically), or 'self' angular momentum; QM spin isn't classical (it's part of a particle's matter-wave), but evolves classically in measure-spaces.

/

 

p.s. ...or just repost your edited version below, sorry....

[Boof-head]

Ok, thanks for the header there (I already managed to double-copy a previous post - maybe I hit the send button twice, but thanks again, I mean, again...). Damn there must be an echo in here.

 

Hmm. /consults notes

 

Ok - inner products. These are simple too: they are vector spaces with additional structure. Scalars of the vector pairs form products in an orthogonal fashion. Orthogon means "opposite sided"; the Greek prefixes ortho- para- iso-, denote "opposing, with, identical", (resp.) in general; meta means "above". These are also used in Chemistry. Think of the benzene ring and the positions on it, or propane's alcohol derivatives - the iso and 'normal' forms or stereochemistry.

 

Benzene exhibits electron delocalization which is a QM 'functionality' but you can explain aromaticity with diophantine characteristic equations (stochasticity); polynomials with a periodic derivative form that characterizes - to a good approximation - the resonant states, or spectrum of benzene chemistry (derivatives of aromatic-ring compounds). Aromaticity is a characteristic of 'smell' - another color to paint (by numbers) for the universal pallete.

[Boof-head]

The only "events" that have any reality to speak of are those in the past, up to and maybe including the present. The only "real" sense with which we can discuss time, is to treat time as the (non-negative) "distance" between any two events, as measured by an observer.

Here we see, in Pyrotex comment, that "now" looks like a limit, as in "up to and maybe including the present".

 

This is actually considering where or how a successor function "is" in the space we are looking at (again, in a literal, real-number sense); The Hawking/Penrose "cone on a curve", has an orthogonal cone reflected at this point p; that we call "the null-point" for an observer. The reflection is an imaginary null-cone in imaginary time; since time is negative when it "flows", positive time lives in the imaginary null-cone, and time is symmetric. The "future" is in an imaginary reflection of the "past", successively, the successor function is "whatever makes it tick over, in the same direction".

 

Thus, there is no view in the model of evolution unless (iff) there is a direction along this null-curve; in that case, the curvature of the space (spacetime with 4 Lorentzian dimensions) becomes time (negative flow) to allow for space (positive background), since all the curvature is at this null-point the apex of the null-cone.

 

Since all the curvature "lives" at the apex, and since there is a flow, time is negative and "space" is positive.

 

The "time limit" that means we have to look "backwards at a past" means that now, as Pyrotex also states, is a "maybe", that it evolves stochastically as a cosmic wave-mechanical product (a time-tensor). This is, in fact quantum probability measure-space. Here the modern science of quantum circuitry, and quantum computing comes in handy; it's a toolbox for quantum technicians who can read a manual.

 

The manual says about time measurement: "quantized space evolves discretely, and time is discrete. This is apposite to universal, or continuous imaginary time, which allows for the space in which quanta are universally gauged (see gauge exchanges section)"

[Boof-head]

Let's take another look at this idea of a "flow'.

 

We have a general conception of a current, as in a flowing liquid such as water (so, since this is ubiquitous locally, the concept can be assumed to be innate - we know about liquids and how they behave, as we understand solids and gases). Liquids are a kind of "in-between" form of matter; solids are deformable but gases are free to translate away from any "pushing" unless constrained in a container; these containers are usually solid - although we've learned recently to constrain or bound a gas of heavy atoms, which are usually metals, by using heat.

 

We extract heat locally - we lower a certain threshold locally, but globally the 'heat boundary' remains.

 

Flow and viscosity is liquids is, as I claim, somewhere between solid and gas phases that have corresponding 'viscosity parameters' these are elasticity and plasticity in solids, and viscosity in gases; liquids retain their volume unlike a gas; viscosity and plasticity (not elasticity) are also retained.

 

These three parameters are tied fundamentally to charge distribution in general; magnetic interactions are in a dual space. Polarity and ionization, in all three matter phases, is generally what 'orders' them; frictional and resistive 'forces' prevent the free flow of heat, charge or magnetic flux through any medium.

 

All are described in terms of potential; potential is another very general term for many things, abstract and physically real.

Now, "physically real" is something of an epistemological topic, and ties to the Aristotelian/Kantian philosophical view that we have used in scientific exploration to develop the modern form of "method", experiment and empiricism; QM has forced this view to be altered, in ways that appear to inform us we can actually know nothing at all.

Since we only can "know" that any information we receive, from any such experiment/empiricism will always be space and time "codes" - length, mass, charge, any potential is always "received" or recorded in terms of arbitrary units of space and time.

 

The "I word", in my experience, often gets an unfair opinion or two; mentioning that information cannot be transferred from one place to another unless work is done (because information has to be "encoded" physically), sometimes gets responses that indicate to me, at least, that there is some confusion, or misconception. The subject isn't mysterious or peculiar, it's pedantic: there is no way to store information, other than in a physical medium, therefore information requires physicality, the flow of information (communication) requires energy (as work), or there is no flow possible.

 

Shannon's theories uncover something basic about our experience and the universe itself - but what?

Something simple and obvious, and something a few physicists appear happy to ignore. But then it is one of those background things we take for granted. After you've acknowledged it's reality, you can put it in the background; however it does not "go away". So what can we ignore that is always there?

 

(Another hint: I believe I know what, but I'm not going to say just yet - it might be a misunderstanding, which is a common response I get at times, when trying to discuss it.)