Space / time . I want to quote

[BackAgain]

I already told you.

There's no such thing as "nothing".

That’s nonsensical.

You're stuck in linear thinking.

Another vague way of reasserting your claim, but absent much meaning.

"Causality" is a linear concept. It's defined in terms of conditional expectations.

Not really. If one thing can’t happen without a certain condition being filled, it’s not simply a matter of “expectations.” And it’s also unclear what you mean when you speak of “linear.”

Check "Granger causality".

I will check it.

What you're asking about, is explained by something called "partitions of zero" (or sometimes, partitions of the origin).

Sounds cool. Also sounds like absolutely meaningless mumbo jumbo.

Ultimately this train of thought boils down to a question of what constitutes "the system", and the answer is, nothing exists in isolation. In real life there's no such thing as a closed system.

Actually, that’s untrue. They may not be eternal, but closed systems certainly exist. And of course we use them and depend upon them quite often.

I don’t suggest we’d want to do this. But if you pour pure salt or whatever into a glass bottle and properly seal the lid and put that now sealed bottle into another container which has all the air removed from it and is itself also then sealed, and you lock that set of containers in a safe which is also vacuum sealed … (whew) …
And a couple of hundred years later a future scientist carefully opens the safe, the sealed vacuum box will still be there. And within it will be the sealed bottle. And within that will be the substance you originally sealed in the jar. None of it will have escaped. Nothing will have been added. Why? Because those systems were closed.

So yeah, maybe there was something "before", but maybe not.

“Maybe.” “Maybe not.”

If the Big Bang created space/time/matter/energy then there still had to have been some instant before there was time. A time before time can’t be measured using time I guess. But there had to have been something prior to the creation of time itself

That certainly clears that up.

Maybe time is compactified and the end joins the beginning like a circle. There are viewpoints that say time doesn't exist "at all", it's just an artifact.

We live in time. So, it exists.

And if time is a closed circle, that’s all well and good. I guess. But where did that circle come from?

 

[scruffy]

That’s nonsensical.

No, it's not. The vacuum of empty space is full of "stuff". It's not empty.

Actually, that’s untrue. They may not be eternal, but closed systems certainly exist. And of course we use them and depend upon them quite often.

No... long range interactions are part and parcel of the quantum world. There's no way to eliminate them completely.

I don’t suggest we’d want to do this. But if you pour pure salt or whatever into a glass bottle and properly seal the lid and put that now sealed bottle into another container which has all the air removed from it and is itself also then sealed, and you lock that set of containers in a safe which is also vacuum sealed … (whew) …
And a couple of hundred years later a future scientist carefully opens the safe, the sealed vacuum box will still be there. And within it will be the sealed bottle. And within that will be the substance you originally sealed in the jar. None of it will have escaped. Nothing will have been added. Why? Because those systems were closed.

lol

The system is half open and half closed until it's observed. Both open and closed, dead and alive like the cat.

If the Big Bang created space/time/matter/energy then there still had to have been some instant before there was time. A time before time can’t be measured using time I guess. But there had to have been something prior to the creation of time itself

How can there be a prior if there is no time?

That certainly clears that up.

We live in time. So, it exists.

How can we make statements like that if we can't define time?

Physics says, there's a threshold below which we can't see, we can only make probabilistic inferences. Therefore, "points" in time make no sense - we have to consider "intervals" instead, because if they're large enough we can measure them.

And if time is a closed circle, that’s all well and good. I guess. But where did that circle come from?

Compactification (at least the one-point version) means that all points "sufficiently far away" become equivalent.

So for example, + infinity = - infinity. The effect of joining the two endpoints of the real line is to "bend them upwards" into a circle. And more than that, if you do it kindly and gently, the point at infinity ends up lining up vertically with the point at 0.

To see what this means and what it looks like, the prototypical example is the Riemann sphere, which looks like this:

In this example the sphere is centered at the origin, but that doesn't always have to be the case.

So this is an example of a "Flatland" where we humans live in a lower dimensional projection of a larger construction.

Many physicists including Dirac and Wigner and others have considered complex (two-dimensional) time, so far it's useful computationally but has no agreed upon physical meaning.

 

[scruffy]

Here -

Empty space:

What keeps space empty?

Space is not empty. A point in outer space is filled with gas, dust, a wind of charged particles from the stars, light from stars, cosmic rays, rad...

wtamu.edu

Zero point energy:

Zero-point energy - Wikipedia

en.wikipedia.org

The cosmological constant has to do with the expansion of the universe.

This is what the vacuum looks like:

Quantum fluctuation - Wikipedia

en.wikipedia.org

Fluctuations create particles from "nothing", they are essentially "partitions of nothing", they're always created in antiparticle pairs and when they annihilate they go back to being nothing.

 

[Blues Man]

Just heard this from a Princeton professor

Energy and matter tells space and time how to be shaped

. How Space / time is shaped tells matter how to move in space / time

Fascinating

Energy and matter are the same thing

 

[BackAgain]

No, it's not. The vacuum of empty space is full of "stuff". It's not empty.

I know.

No... long range interactions are part and parcel of the quantum world. There's no way to eliminate them completely.

The gospel truth?

lol

The system is half open and half closed until it's observed. Both open and closed, dead and alive like the cat.

Nonsense.

How can there be a prior if there is no time?

Exactly.

How can we make statements like that if we can't define time?

We do define time. But we can’t define time before there was time. And if everything (including time) was created by the Big Bang then where did that little tiny spark of everything come from?

Physics says, there's a threshold below which we can't see, we can only make probabilistic inferences. Therefore, "points" in time make no sense - we have to consider "intervals" instead, because if they're large enough we can measure them.

The use of the term “point in time” isn’t really under discussion.

Compactification (at least the one-point version) means that all points "sufficiently far away" become equivalent.

More babble.

So for example, + infinity = - infinity. The effect of joining the two endpoints of the real line is to "bend them upwards" into a circle. And more than that, if you do it kindly and gently, the point at infinity ends up lining up vertically with the point at 0.

Not necessarily. Start at zero. Draw the line to the right — at 90 degrees — and it goes on forever. Do the same but to the left at 90 degrees and it goes on forever.

If left represents the line on which fall all negative numbers and right represents the line on which fall all positive numbers, you have a graphic representation of negative to infinity and positive to infinity.

To see what this means and what it looks like, the prototypical example is the Riemann sphere, which looks like this:

View attachment 759354

In this example the sphere is centered at the origin, but that doesn't always have to be the case.

So this is an example of a "Flatland" where we humans live in a lower dimensional projection of a larger construction.

Many physicists including Dirac and Wigner and others have considered complex (two-dimensional) time, so far it's useful computationally but has no agreed upon physical meaning.

Once again: gibberish.

Well, it might as well be. For words to have meaning to a listener, they have to be understandable. Lacking a background in higher math and physics, it isn’t understandable to me.

 

[scruffy]

Once again: gibberish.

Well, it might as well be. For words to have meaning to a listener, they have to be understandable. Lacking a background in higher math and physics, it isn’t understandable to me.

You just have to use your imagination.

Let's say you're standing on top of the sphere on the point(s) at infinity, what do you see?

Well, the interesting thing about projective geometry is the space is "curved". So for instance, if you're looking straight down you see the point at 0, and you'll note, that as you sweep through a 10 degree angle in either direction, you're not covering very much distance on the projection.

On the other hand, if you look in the direction of the vector A in the diagram, and similarly sweep 10 degrees in either direction, the distance covered on the x axis is much, much larger.

So, the projection has the effect of magnifying the area around the origin. If this were an eyeball, it would be exactly the desired increase in precision around the fovea. And, in a real eye, we find exactly that. Foveal receptive fields are small and very precise and there are lots of them.

A pinhole camera is projective geometry, a Riemann sphere is curved projective geometry. The reason this matters is because depending where you look, the metric (metric tensor) changes.

 

[scruffy]

All right, we're still talking about the OP.

The metric tensor is the curvature of spacetime, much like in the Riemann sphere example.

The Riemann sphere, happens to have a constant curvature, but generally, anything with mass will cause a curvature, which is what the OP's talking about. So you end up with these different curvatures all over the place, and your spacetime ends up looking like a "terrain".

There are different ways of compactifying, for example in 2 dimensions you can curl one dimension up and one down, to get a torus.

We might be talking about what happens at "very small scales", way below the size of an atom, or even a photon.

Curvature of spacetime changes the perceived physical laws (but not the real ones). And "curvature" is an interesting concept, because for example, statistical manifolds are curved - but in the opposite way, they're hyperbolic. So you get saddle shapes instead of spheres.

Anyway, I will continue to explain in the other thread, why information theory is deeply flawed. Leo Szilard calculated how much energy it takes to flip a bit. Turns out, it depends how many states your bit has. If it's binary 0 or 1, you use log base 2, whereas if it"s decimal you use log base 10.

 

[scruffy]

Here is a quantum teleportation protocol, which "apparently" extracts energy from nothing.

But not really... it's drawing it from the vacuum of empty space.

Which, as we now know, is not "empty".

Physicists Use Quantum Mechanics to Pull Energy out of Nothing | Quanta Magazine

The quantum energy teleportation protocol was proposed in 2008 and largely ignored. Now two independent experiments have shown that it works.

www.quantamagazine.org

 

[scruffy]

We live in time. So, it exists.

But you still can't define it.

You want me to show you how bad your lack-of-definition is?

You say we live "in" time. Well, consider a brain. There, we have two distinctly different kinds of time. One is called physical, the other is called psychological. Both are real and can be measured.

Physical time, is the dt we're all familiar with, and the f(t) we're all familiar with. In physical time, we can obtain information about "t - dt" if our function has memory (which many nonlinear functions do, see Volterra kernels), but we can not obtain information about "t + dt".

However in psychological time, we CAN (and do) obtain information about t + dt, and as a matter of fact, in the limit as dt => 0, expectation and reality become one and the same. By definition. Our brains do in fact predict the future - quite reliably.

Now - you can argue (but not prove) that psychological time is just an artifact, but I suggest exactly the opposite is true. There is a CONSTRAINT that prevents a backward flow of physical time. What that is specifically, we don't yet know. There are model scenarios in which loops of physical time occur, and there are also time crystals and such - but think about this: our brains are asked to optimize behavior at the moment called "now" - even though, our brains can not possibly know when that moment is! Our brains can not define "now", because there are always conduction delays associated with neural signals. Our brains have to "estimate" where now is.

 

[ReinyDays]

But you still can't define it.

You want me to show you how bad your lack-of-definition is?

You say we live "in" time. Well, consider a brain. There, we have two distinctly different kinds of time. One is called physical, the other is called psychological. Both are real and can be measured.

Physical time, is the dt we're all familiar with, and the f(t) we're all familiar with. In physical time, we can obtain information about "t - dt" if our function has memory (which many nonlinear functions do, see Volterra kernels), but we can not obtain information about "t + dt".

However in psychological time, we CAN (and do) obtain information about t + dt, and as a matter of fact, in the limit as dt => 0, expectation and reality become one and the same. By definition. Our brains do in fact predict the future - quite reliably.

Now - you can argue (but not prove) that psychological time is just an artifact, but I suggest exactly the opposite is true. There is a CONSTRAINT that prevents a backward flow of physical time. What that is specifically, we don't yet know. There are model scenarios in which loops of physical time occur, and there are also time crystals and such - but think about this: our brains are asked to optimize behavior at the moment called "now" - even though, our brains can not possibly know when that moment is! Our brains can not define "now", because there are always conduction delays associated with neural signals. Our brains have to "estimate" where now is.

Time is an artifact ... a creation of biology ... nothing more ... and most species only care about season, and not time as humans created ... is time defined by motion or is motion defined by time? ... without motion, is time useful? ... 300 million meters in a second ... time and motion are the same thing, just different ways to measure ...

"Tis said that the world's smartest people cannot divise a more complicated or convoluted system of time measure that what we use today ... I blame Sir Issac Newton, the brat ...

 

[para bellum]

Time is an artifact ... a creation of biology ... nothing more ... and most species only care about season, and not time as humans created ... is time defined by motion or is motion defined by time? ... without motion, is time useful? ... 300 million meters in a second ... time and motion are the same thing, just different ways to measure ...

Well, there are other ways to measure "time" that do not rely on motion. Radioactive decay for example. We call "a year" the amount of time it takes the earth to orbit the sun, but we can measure time independent of that if we want to.

Time is a dimension- it has an origin point and it varies only in scale. I was born in 1960, and I will never receive information from before then. For me, time began in 1960. I can't experience something that happened before I was born.

Physics puts the beginning of time at the big bang, mostly out of convenience. That's when the universe was "zero" old. Spacial dimensions and temperature work the same way. You can't go to the lumber store and buy a 2x4 that is -3 feet long. There is no such thing. The length of something physical begins at zero. Likewise, nothing exists below absolute zero -it's the origin point for temperature.

 

[ReinyDays]

Well, there are other ways to measure "time" that do not rely on motion. Radioactive decay for example. We call "a year" the amount of time it takes the earth to orbit the sun, but we can measure time independent of that if we want to.

Time is a dimension- it has an origin point and it varies only in scale. I was born in 1960, and I will never receive information from before then. For me, time began in 1960. I can't experience something that happened before I was born.

Physics puts the beginning of time at the big bang, mostly out of convenience. That's when the universe was "zero" old. Spacial dimensions and temperature work the same way. You can't go to the lumber store and buy a 2x4 that is -3 feet long. There is no such thing. The length of something physical begins at zero. Likewise, nothing exists below absolute zero -it's the origin point for temperature.

Radioactive decay involves motion ... and momentum ... Alpha decay is a helium nucleus ... and this helium is moving away from her parent nucleus ...

The question I was answering was "how do we define time" ... Newton defined it in terms of the motion caused by a force applied over ... time ... so are we defining time in terms of motion or are we defining motion in terms of time? ... or just skip the question and start with F=ma? ...

SI defines a second in terms of the motion of a photon ... I personally use heart beats ... the motion exists and we perceive it ... "time" is the artifact we use to judge one motion from another ... time is the difference between a Randy Johnson fastball and the exit velocity of an M-61 Vulcan Gatling gun ...

=====

Time has always been a dimension ... f(x,y,z,t) ... for me (and in spherical co-ordinates), this is f(6,000 miles, 38ºN, 120ºW, 1961 AD) ... which is fine if a mile is a mile, a degree-of-arc is a degree-of-arc and a year is a year ... and that's a SAFE assumption to make for human sized objects ... for Mercury, a mile isn't a mile and a year isn't a year ... so we'll need a better definition of time there ... it's more of a curiosity here ...

yeah, UCSF, so what? ...

 

[para bellum]

Radioactive decay involves motion ... and momentum ... Alpha decay is a helium nucleus ... and this helium is moving away from her parent nucleus ...

That is one type of radioactive decay, but there are others that do not involve the loss of nuclear particles.

C14 decays to N14 when a neutron in the C14 emits an electron and an anti-neutrino. a neutron is converted to a proton and the C14 becomes N14.

This is very different than measuring the motion a mass. A unit of time, say one year, could be defined as the amount of time it takes 1/5700 of a mass of C14 to decay to N14. That would make "one year" the same as the definition "the amount of time it takes the earth to orbit the sun".

It does not matter if you are standing on Mercury, an "earth year" is still an "earth year" and it will still be the period where 1/5700 of the C14 decays to N14.

What I am saying is that time is not an artifact of biology and does not rely on classical Newtonian physics. It exists independent of life. The units of measure (day, month, year) we use are human artifacts, but the units are not the thing.

Time is an artifact of the fundamental forces of the universe. If you use planetary motions to define a unit of time, it's gravity that governs. If you use radioactive decay, it's the weak nuclear force or electromagnetism or the strong nuclear force that's responsible.

 

[scruffy]

Well, there are other ways to measure "time" that do not rely on motion. Radioactive decay for example. We call "a year" the amount of time it takes the earth to orbit the sun, but we can measure time independent of that if we want to.

Time is a dimension- it has an origin point and it varies only in scale. I was born in 1960, and I will never receive information from before then. For me, time began in 1960. I can't experience something that happened before I was born.

Physics puts the beginning of time at the big bang, mostly out of convenience. That's when the universe was "zero" old. Spacial dimensions and temperature work the same way. You can't go to the lumber store and buy a 2x4 that is -3 feet long. There is no such thing. The length of something physical begins at zero. Likewise, nothing exists below absolute zero -it's the origin point for temperature.

Negative temperature - Wikipedia

en.wikipedia.org

"Temperature" is not a direct physical observable. It's usually defined in terms of an average of kinetic energies or some such thing.

There is some question, as to whether time is directly observable, or whether it is some kind of "population average" like temperature. The way we generally measure it, with a large free standing clock, would seem much like a thermometer.

In physics the arrow of time is related to the question of irreversibility, and irreversibility seems to be much related to complexity. A further hint that there may be a finer grain to "time" than we've seen so far.

 

[scruffy]

Bing bang boom.

"Also, the time needed to complete the process depends on the amount of information the system can store," Navascués added.

Scientists Say They Can Reverse Time in a Quantum System

An international team of scientists claim to have found a way to speed up, slow down, and even reverse the flow of time for a given quantum system.

futurism.com

Pats self on back.

It doesn't have to do with biology, or even radiation. It has to do with information.

Radiation, is information. In a way. And, radioactive decay has Poisson statistics, which is kind of a "model of time" - but note - it is as I said, it is interval based rather than point based.

This is a huge clue. If it were a direct observable it would be point based, or path based. Instead we have "all possible paths" over an interval.

The only way to measure the 'passage of time", is to use system state as a metric. If the system remains in the same state forever, it is impossible to measure the passage of time in it. If we put a ticking clock in the middle of such a system, clearly, the clock becomes part of the system and therefore the system changes states.

 

[ReinyDays]

That is one type of radioactive decay, but there are others that do not involve the loss of nuclear particles.

C14 decays to N14 when a neutron in the C14 emits an electron and an anti-neutrino. a neutron is converted to a proton and the C14 becomes N14.

This is very different than measuring the motion a mass. A unit of time, say one year, could be defined as the amount of time it takes 1/5700 of a mass of C14 to decay to N14. That would make "one year" the same as the definition "the amount of time it takes the earth to orbit the sun".

It does not matter if you are standing on Mercury, an "earth year" is still an "earth year" and it will still be the period where 1/5700 of the C14 decays to N14.

What I am saying is that time is not an artifact of biology and does not rely on classical Newtonian physics. It exists independent of life. The units of measure (day, month, year) we use are human artifacts, but the units are not the thing.

Time is an artifact of the fundamental forces of the universe. If you use planetary motions to define a unit of time, it's gravity that governs. If you use radioactive decay, it's the weak nuclear force or electromagnetism or the strong nuclear force that's responsible.

All forms of radioactive decay involves a change in momentum, which in turn effects motion ... and E=mc^2 allows us to assign momentum to photons (= gamma emission) ... we only claim photons have no rest mass ... they certain carry momentum as demonstrated by these solar sails the Japanese have ...

I'm asking for a definition of time ... we know exactly what a second is ... "half-life inner shell something something" and we use caesium a lot ...

I understand you're treating time as a dimension ... for the meteorology and geology that interests me, using time as the standard works best when everything is moving, but I can see the proofs using the [some goobly-guke] just fine, they're just useless to me at my level of education (or lack thereof) ... we keep speeds under 0.9c, and we're good with Newton all day long ...

 

[ReinyDays]

Negative temperature - Wikipedia

en.wikipedia.org

"Temperature" is not a direct physical observable. It's usually defined in terms of an average of kinetic energies or some such thing.

There is some question, as to whether time is directly observable, or whether it is some kind of "population average" like temperature. The way we generally measure it, with a large free standing clock, would seem much like a thermometer.

In physics the arrow of time is related to the question of irreversibility, and irreversibility seems to be much related to complexity. A further hint that there may be a finer grain to "time" than we've seen so far.

Temperature scales don't change ... whereas time does ... we can look and see the motion of the jet emitting from the external galaxy M-81 ... using "Earth seconds", the speed is somewhere north of five times the speed of light !!! ... however we need to use the seconds as they occur there in the jet, and we get the more realistic 0.999c ...

Would temperature, pressure or relative humidity be effected in the same way? ... except they all depend on time as an absolute value? ...

=====

No ... and we invented an new definition of temperature to take care of that ... and new "microscopic" forms of the Laws of Thermodynamics ... alas, field theory is over my pay grade ...

 

[scruffy]

Brain activity is characterized by a high dimensional chaotic ground state from which transient spatiotemporal patterns (metastable states) briefly emerge.

Sound familiar?

Sounds a bit like the vacuum of space?

 

[ReinyDays]

Sounds a bit like the vacuum of space?

The brain activity here on USMB? ... almost, not quite, just more of a vacuum than low Earth orbit ...

 

[scruffy]

A Revolutionary New Physics Hypothesis: Three Time Dimensions, One Space Dimension

How would our world be perceived by observers moving faster than light in a vacuum? According to theorists from Warsaw and Oxford universities, such a view would differ from what we encounter daily, with the presence of not only spontaneous phenomena but also particles traveling multiple paths simul

scitechdaily.com