Time Paradox!

[EStein]

end of discussion.

 

Agreed.

You obviously want to invalidate everyone's points but your own. Go for it. Some of my points were hypothetical; some were not. It was somewhat difficult to understand where you're coming from. Explain it to others. I'm through with you.:hihi:

[arkain101]

Estein, have you read much of my posts?

 

Any thoughts? I am interested because I spend alot of time on this work.

[EStein]

Estein, have you read much of my posts?

 

Any thoughts? I am interested because I spend alot of time on this work.

 

Yes, I quite enjoyed saddling the electron and scolding...I mean..er..lecturing the children on tubular, streaking universes. You made it a real mind journey and I can tell you took your time one it. I also enjoyed the deeper intellictual points you offered. I love it when other's ideas take me down a path I have never been or at least have not been in a while. Thanks arkain. I always enjoy your posts and will comment more later. Right now, I'm a little sore from a beating I just endured. It's OK, it was a sincere thrashing administered with love and kindness.:hihi:

[Farsight]

Oh come on Popular, as soon as someone comes up with a good counterpoint you abandon your position, dont let him win because you didnt like the way he talked to you - why dont you explain to us (without sending us to one of your essays) what you mean by and why you think there is 'absolute space'

 

Imagine that you, I, and arkain are travelling in orthogonal directions at .99c. We pass each other and exchange information, making allowance for our orthogonal directions. I report that the universe is 28 x 28 x 4 billion lightyears in extent. You say it's 28 x 4 x 28 billion lightyears, and arkain says its 4 x 28 x 28 billion lightyears. Our measurements are not reconcileable. We can't all be right. So we agree that our measurements must have been relative, resulting from our velocities through this universe.

 

So we then we meet up to examine Cosmological Background Radiation and adjust our common velocity and position so that it is equal in intensity and frequency from all directions. We then assert that to the best of our knowledge we appear to be motionless in the centre of the universe, and since the universe is everything by definition, we consider ourselves to be motionless at the centre of space.

 

We then claim that our measurements of space from this position and local velocity to be "proper" measurements of all space, and that all other measurements are relative to motion through it, akin to our first measurements. Since there is no other space, there is nothing else for our measurements to be relative to.

 

Of course, we need to make some calibration for ongoing expansion, and remain aware that space at one end of the universe is receding from the space at the other. And we mustn't be too emphatic in case we later find out that what we thought was the universe was just the observable universe, or that it isn't spherical. But since the universe is what we're trying to learn about in physics, and because it's everything, there's no sense in saying its relative, or that it's space is relative. The universe is absolutely everything, so the space we measured is effectively "absolute".

 

 

 

You might say the same about time, but the universal time you end up with will be inferred from distances in absolute space and velocities through it. It's based on light years and on your definition of a second, which is determined by the velocity of an electromagnetic effect within the space of an atom:

 

Under the International System of Units, the second is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom...

 

It's based on velocity through your absolute space, and so is derivative and cannot be considered to be absolute, particularly since relativistic time dilation permanently alters your experienced time, but not the absolute space.

[Qfwfq]

It's based on velocity through your absolute space, and so is derivative and cannot be considered to be absolute, particularly since relativistic time dilation permanently alters your experienced time, but not the absolute space.

I think I maybe get your drift about the definition of a second being derivative, despite the fact that the velocity of the emitted radiation isn't essential in this definition.

 

Basically, a consequence of the work of Einstein and Minkowski is that lengths and intervals of time are simply two different classes of direction in the space-time geometry. With natural units, c = 1 and velocities are adimensional. It's only for practical everyday purposes that we use huge units of time and tiny units of length. The habit is so ingrained that even astronomers talk about light-years when, according to Minkowski, they could really just talk about lengths in years. If the time you take to travel is longer than the length of the path projected onto the spatial axes, it simply means that your velocity is less than 1 or, in other words, your world line's angle has a tangent less than 1.

 

I don't however see how this leads to demonstrating the existence of an absolute space.

[CraigD]

Imagine that you, I, and arkain are travelling in orthogonal directions at .99c. We pass each other and exchange information, making allowance for our orthogonal directions. I report that the universe is 28 x 28 x 4 billion lightyears in extent. You say it's 28 x 4 x 28 billion lightyears, and arkain says its 4 x 28 x 28 billion lightyears. Our measurements are not reconcileable. We can't all be right. So we agree that our measurements must have been relative, resulting from our velocities through this universe.

I’m left in a state of semantic bewilderment. If, by agreeing that our measurements must have been relative (and having an exact theory describing this relativity), we are able to reconcile our differing measurements, how can we say our measurements are not reconcilable?

… We then assert that to the best of our knowledge we appear to be motionless in the centre of the universe, and since the universe is everything by definition, we consider ourselves to be motionless at the centre of space.

Note that all Special Relativity postulates is that the laws of physics, including our measurement of the speed of light in vacuum, are the same for all three of us. It doesn’t assert that we’ll be unable to detect that we’re all moving very differently than the rest of the observable matter in the universe. In addition to the length contraction mentioned, the Doppler (blue and red) shift we’d measure from ordinary objects like stars and our radio transmitters (or com lasers, or whatever we’re using to communicate) would be dramatic (so much so that I’m glad it’s Popular, Jay, and arkain out there coping with .99 c blueshifted photons and micrometeorites, not me! :eek: ).

 

In short, relativity says that no one unique inertial frame is privileged. It doesn’t say that no inertial frame is less weird than another.

Of course, we need to make some calibration for ongoing expansion, and remain aware that space at one end of the universe is receding from the space at the other. And we mustn't be too emphatic in case we later find out that what we thought was the universe was just the observable universe, or that it isn't spherical. But since the universe is what we're trying to learn about in physics, and because it's everything, there's no sense in saying its relative, or that it's space is relative. The universe is absolutely everything, so the space we measured is effectively "absolute".

But which inertial frame would we designate as “absolute space”? Surely not that of our .99 c spacecraft – despite their intact laws of physics, they’re far to weird. The barycenter of the Milky Way galaxy? Why not the Andromeda Galaxy? (after all, it is about 25% more massive) The Local Group of galaxies of which the Milky Way and Andromeda are members? The Local Supercluster of which the Local Group is a member? Or, perhaps through a colossal cataloging of the visible universe, we can determine its center of mass, and chose it?

 

All of these have relative velocities of appreciable magnitude, to the extent that if we chose one, ordinary observations in most of the space within its domain will be weird, and require relativistic corrections.

 

In short, though it appears we can designate an single frame as arbitrary space, none seems a candidate for absolute space.

… but the universal time you end up with will be inferred from distances in absolute space and velocities through it. It's based on light years and on your definition of a second, which is determined by the velocity of an electromagnetic effect within the space of an atom:

 

Under the International System of Units, the second is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom...

Though I don’t think Popular is denying it, it bears reasserting that, according to Relativity and a wealth of observed data, the transition times used in this standard really do vary with the relative motion and gravity of their observers – atomic clocks on fast-moving vehicles or on planet surfaces “tick” observably slower than slow-moving ones, or ones far from planets.

 

In short, there is not device that can “latch on” to some absolute time from which we might determine an inertial frame for absolute space.

 

So, an absolute spatial coordinate system would be weird and difficult to use in nearly all of the interesting places in the universe, and may be impossible to non-arbitrarily determine. To my thinking, this heaves the concept of “absolute space” into the waste bin of “useless physics concepts”, with considerable authority.

[Farsight]

I’m left in a state of semantic bewilderment. If, by agreeing that our measurements must have been relative (and having an exact theory describing this relativity), we are able to reconcile our differing measurements, how can we say our measurements are not reconcilable?

 

Craig: It tells us that relativity affects our measurements of space, not the actual space. A rotating planet is not flattened to a disk-like shape because we flash past it at some relativistic speed. We confer, and agree that it cannot be a disk if we observed it to be disk-like from three orthogonal directions. We agree that is likely to be spherical. And then we apply the same thinking to the entire universe, to all of space, and to all parts of it.

 

Note that all Special Relativity postulates is that the laws of physics, including our measurement of the speed of light in vacuum, are the same for all three of us.

 

Yes it does. But it doesn't explain why. And to seek the answer we have to look at time. We see that it is a derived effect of motion through space. It has no "length". It does not "flow". You have no freedom of movement through it. Minkowski spacetime is a mathematical space. Yes we calculate with it, and those calculations are precise. But it is not real, there are no world lines, there is no block universe. There is no time travel, there are no time paradoxes. All these abstract things have to be consigned to the waste bin, along with inertial reference frames, because none of them are there.

 

And then when we actually look at the universe, the universe we seek to learn about through physics, we see space, and motion through it. And because our universe is absolute, its space is absolute too. Yes, an absolute spatial coordinate system would be weird and difficult to use. Perhaps even impossible. But the space is there, because the universe is there.

 

It isn't absolute space that has to be heaved into the wastebin. It's time the dimension. An improved Relativity doesn't just postulate, it explains. And when you take the time out of spacetime all you've got left is space. And when you look further you realise that it's the light moving through it that makes it the thing that it is, and it's the only thing that there is. It makes it Einstein's pure marble dream. And it makes it absolute space.

[EStein]

What is a space time continuum?

In 1906, soon after Albert Einstein announced his special theory of relativity, his former college teacher in mathematics, Hermann Minkowski, developed a new scheme for thinking about space and time that emphasized its geometric qualities. In his famous quotation delivered at a public lecture on relativity, he announced that,

 

"The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. henceforth, space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality."

I see nothing of an "absolute space", here.

[arkain101]

It makes it Einstein's pure marble dream. And it makes it absolute space.

 

Is space itself not reason?

 

Is reason itself not steadfastly intwined with life?

 

Is thought not intangible?

 

Is intangibility reasonable?

 

Is reason existence?

 

Is existence a mind, a very powerful mind, eminating in your mind?

[CraigD]

Is space itself not reason?

Yes. Space is not reason. There is no evidence of rational processes occurring in “pure space” – vacuum.

Is reason itself not steadfastly intwined with life?

Yes. Although current observation shows that algorithmic, rational processes exhibited by living organisms are much more effective than those exhibited by non-living (non-biologica) machines, these processes are present in both the living and non-living.

Is thought not intangible?

Yes. “Intangible” means “cannot be touched” Though is not intangible. Though is the result of myriad interactions – “touchings” within the biological nervous systems. Thought has not been observed outside of these biological systems.

Is intangibility reasonable?

Yes. Rational processes can be used to define the concept of tangibility, and its complement, intangibility. By the common, broad definition, intangible things cannot be observed.

Is reason existence?

No. The known laws of physics do not require the existence of rational processes.

Is existence a mind, a very powerful mind, eminating in your mind?

No. “Emanate” means “comes out of”. No evidence suggest that any substance comes out of a “mind”. The term “mind” is a category for processes found in certain biological systems, such as human brains.

 

These questions, and answers, appropriately for this forum, are within the knowledge domain of physics. Answer should also be within this domain, meaning that they must be supported by reproducible, experimentally verifiable evidence.

[Farsight]

I think I maybe get your drift about the definition of a second being derivative, despite the fact that the velocity of the emitted radiation isn't essential in this definition.

 

There's something moving inside the atom that results in the radiation. It's arguably the same kind of "stuff" as the radiation, but whether it is or isn't isn't that important. It's like this: if the world was a movie full of people who could think and conduct experiments, then if you ran the movie in slow motion, they wouldn't know.

 

Basically, a consequence of the work of Einstein and Minkowski is that lengths and intervals of time are simply two different classes of direction in the space-time geometry. With natural units, c = 1 and velocities are adimensional. It's only for practical everyday purposes that we use huge units of time and tiny units of length. The habit is so ingrained that even astronomers talk about light-years when, according to Minkowski, they could really just talk about lengths in years. If the time you take to travel is longer than the length of the path projected onto the spatial axes, it simply means that your velocity is less than 1 or, in other words, your world line's angle has a tangent less than 1.

 

I don't however see how this leads to demonstrating the existence of an absolute space.

 

How can I put this? A world line does not actually exist. Seen one recently? It doesn't have a tangent because it's just not real. A "length" of time does not actually exist. You cannot "travel" it in some direction. You just sit there not moving, and meanwhile everything around you does move, including your clocks. The only travelling going on is in space. Space is real. It's there. Lengths don't contract when you move with a real velocity that gets you from A to B. They only appear to contract, to you. How do all these things that don't exist disprove something that is actually there? Truth is they don't. These things are abstractions, concepts, convention. The habit of Minkowski Spacetime is so very deeply ingrained. Einstein wasn't too happy with Minkowski when he introduced it, but was persuaded. IMHO that was his greatest mistake.

 

Have a read of this: home . It isn't proof, just an interesting way of looking at things. You have to look at it objectively otherwise it just doesn't click. Once you see it, once you understand time for what it is (a measure of motion rather than a dimension you can actually move through) you have to step down from spacetime to absolute space. And you realise it's Einstein's dream, his pure marble.

[Qfwfq]

A world line does not actually exist. Seen one recently? It doesn't have a tangent because it's just not real.

A circle isn't real either. It's an abstraction. Does this mean it can't have a tangent? No, the tangent is a line, so it too is an abstraction and doesn't require something real. Geometry is an abstraction but it is handy in describing things. I wasn't trying to sell you a kilogram of world lines.

 

Have a read of this: home . It isn't proof, just an interesting way of looking at things.

Obviously it isn't a proof because it's a model.

[Farsight]

I can take a piece of chalk and draw a circle on the pavement. I can then look at it. It looks like this:

 

 

I can walk round it, measure it, and draw a line at a tangent to it.

 

OK, here's the chalk: now draw me a world line.

[Qfwfq]

That isn't a circle!

 

What's on your floor can be roughly described by a circle. A circle is no more real than a world line, which is an ideal description of a corpuscle's motion.

[Farsight]

I can whirl a sparkler and see a circle.

 

Can you see a world line?

 

No.

 

Can you see motion?

 

Yes.

 

The world line is just a concept, just like a length of time and time flows and days pass and clocks run and time travel and the block universe. In no way do they comprise an ideal description, nowhere near. The ideal description describes what you actually see. Space is there and there's motion through it. Time is just a measure of this motion against other motion. And the notion of travelling through a measure of motion is utterly absurd. It's just so obvious once you see it. But people are so utterly mired in their current concept of time that they just can't see it. Once you do, if you do, you'll be amazed.

[EStein]

Funny as it might sound, a world line may possibly be "viewed" from another dimension. Instead of appearing as blobs moving from place to place, we might be viewed as streaks in time--growing worms, as it were. From birth to death, I might be viewed as a huge plate of spagetti.

[Qfwfq]

I can whirl a sparkler and see a circle.

You see an image that you describe as a circle. It'll never be a circle, even less than the chalk on your floor. It's an effect of persistence that amounts to projecting the world line onto the space at each moment of time.

 

Can you see a world line?

No, because I only see one moment at a time and I perceive temporal separation differently from how I perceive spatial separation.

 

Can you see motion?

 

Yes.

No! For the same reason as above, except that I'm able to remember previous positions and even have a natural stimulation from change that prolly saved the lives of plenty of my ancestors. Motion gives me an impression that we ordinarily call "seeing motion".

 

Neither can I see a quark.

 

The world line is just a concept, just like a length of time and time flows and days pass and clocks run and time travel and the block universe.

These are figures of speach, yet there are the geometric properties of space-time that give a far better description of dynamics than what was previously used.

 

In no way do they comprise an ideal description, nowhere near. The ideal description describes what you actually see.

Help! :xparty: Semantic ambiguity! Spare me! That's not what I meant!