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Author: Subject: Myth of Streching Space
NEMO-Chemistry
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[*] posted on 6-11-2017 at 17:09


What if space was just 5 dimensions wrapped like some kinda twisted mobious band? If we can draw the shadow of a 4 dimension shape, why cant you have more than 4 dimensions? This makes the assumption, that having seen the drawing of the 4th dimension shadow, you then except it must exist.

If a 4th dimension didnt exist, how can you draw its shadow?

I wonder how much sense the above is going to make to me tomorrow??? having just distilled 300ml of Chloroform, it might not make much. But I can promise you that at the moment it makes perfect sense to me :D.

[Edited on 7-11-2017 by NEMO-Chemistry]
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[*] posted on 7-11-2017 at 04:38


Nah dosnt make any sense today, maybe that proves chloroform makes you smarter then lol :P
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[*] posted on 7-11-2017 at 11:15


It can be useful to think of space-time as having 3.5 dimensions, or seven degrees of freedom. That is, in three of the dimensions, it's possible to move in both directions, but in one of the dimensions, movement is only possible in one direction.

String theory claims something like ten dimensions, but that's basically mathematical masturbation, and I wouldn't put much credibility in it these days.




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[*] posted on 7-11-2017 at 15:52


Attempting to understand how the Universe Actually Is can make you a bit crazy,

Trying to imagine it from the viewpoint of an entity moving along a linear Gravitational line (swapped for our linear Time axis) almost demolished my feeble brain.

Fortunately the cumulative effects of Beer not only hindered this occurrence, but allowed for the 'fuckit' contingency to release the brain from the difficult task of processing what is basically Madness for a human.

I may try again some day, and will definitely be prepared with large stocks of beer in case it goes wrong.




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[*] posted on 8-11-2017 at 02:25


While looking up some definitions of cosmological terminology I found the following text in a note titled: Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the universe by Tamara M. Davis and Charles H. Lineweaver. It was written 14 years ago.

Murdoch's note on this subject is 40 years old. It’s amazing to me that this gobbledygook fairy tales stuff is still around. I guess its because its simpler to understand and teach in spite of the contradictions or maybe it really is the Pi masons LOL

“Popular science books written by astrophysicists, astrophysics textbooks and to some extent professional astronomical literature addressing the expansion of the Universe, contain misleading, or easily misinterpreted, statements concerning recession velocities, horizons and the “observable universe”. Probably the
most common misconceptions surround the expansion of the Universe at distances beyond which Hubble’s law
(vrec=HD : recession velocity = Hubble’s constant × distance) predicts recession velocities faster than the speed of light [Appendix B: 1–8], despite efforts to clarify the issue (Murdoch 1977, Harrison 1981, Silverman 1986, Stuckey 1992, Ellis & Rothman
1993, Harrison 1993, Kiang 1997, Davis & Lineweaver 2000, Kiang 2001, Gudmundssonand Bjornsson 2002). Misconceptions include misleading comments about the observability of objects receding faster than light [App. B: 9–13]. Related, but more subtle confusions can be found surrounding cosmological event horizons [App. B: 14–15]. The concept of the expansion of the universe is so fundamental to our understanding of cosmology and the misconceptions so abundant that it is important to clarify these issues and make the connection with observational tests as explicit as possible.”

The note can be found at https://arxiv.org/pdf/astro-ph/0310808.pdf



[Edited on 8-11-2017 by wg48]
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[*] posted on 8-11-2017 at 04:05


@NEMO If unicorns don't exist, then why can I draw one?

We can make computer models with as many spacial dimensions as we want to, extrapolating from 2D counterparts in 3D. Like, for a 2D square, all of its sides are at 90 degrees to each other. To get a cube, you add another square in the new dimension, the same distance away as one of its sides is long, and connect all of its corners to corresponding corners on the other square. This creates eight new edges, for a total of 12. To move to 4 dimensions and get a hypercube, you create another cube, one side-length away, in the new dimension, adding 12 new edges. Then connect all the 8 corners to corresponding corners on the other cube, adding 8 edges for a total of 32. Hypercube projections in three dimensions can be mind-warping, but this projection is probably the easiest to comprehend:



The fact is though, our universe doesn't show any signs of interacting with a fourth spacial dimension, and so arguing about whether one exists is a lot like arguing about the existence of God.

Quote: Originally posted by wg48  
While looking up some definitions of cosmological terminology I found the following text in a note titled: Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the universe by Tamara M. Davis and Charles H. Lineweaver. It was written 14 years ago. It’s amazing to me that this gobbledygook fairy tales stuff is still around. I guess its because its simpler to understand and teach in spite of the contradictions.

Oversimplifications aren't the same things as lies. If I explain how sunlight forms to a five-year-old, I have to choose between giving an answer that will hopelessly confuse him, or an answer that isn't 100% accurate but is as close to accurate as I think he can understand. The details can be elaborated on when he's old enough to understand them.

Physics professors are in the same predicament. With so many more students attending college than used to, you get a lot of dum-dums who you either hopelessly confuse, or make a judgment call regarding where to draw the line regarding simplification. The people who wrote this article seem to believe that some professors and authors have simplified too much. That's all.

I'm also glad to see that you're studying this stuff more. Knowledge is power, even if it's just the power to better articulate what, specifically is wrong with an oversimplified explanation of the standard model of the universe, without being wrong yourself.




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[*] posted on 8-11-2017 at 14:04


So if spacetime is deformed by the presence of a black hole for example (of which there are many) how can it be argued that over a distance of 13Billion light years the spacetime inbetween point A and B is uniform and contiguous ?

If Not, the calculation of the travel-time of light is a bit off, therefore so is the estimate of the Size of the everything.

If So, black holes and other bodies do Not affect spacetime significantly, which is at odds with established theory.

To be fair, i was struggling to move a boulder the other day and asked my wife to hand me the 5 foot iron bar.

She handed me a tiny teaspoon instead, with a knowing smirk :o




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[*] posted on 8-11-2017 at 14:52


Quote: Originally posted by Melgar  
@NEMO If unicorns don't exist, then why can I draw one?

We can make computer models with as many spacial dimensions as we want to, extrapolating from 2D counterparts in 3D. Like, for a 2D square, all of its sides are at 90 degrees to each other. To get a cube, you add another square in the new dimension, the same distance away as one of its sides is long, and connect all of its corners to corresponding corners on the other square. This creates eight new edges, for a total of 12. To move to 4 dimensions and get a hypercube, you create another cube, one side-length away, in the new dimension, adding 12 new edges. Then connect all the 8 corners to corresponding corners on the other cube, adding 8 edges for a total of 32. Hypercube projections in three dimensions can be mind-warping, but this projection is probably the easiest to comprehend:



The fact is though, our universe doesn't show any signs of interacting with a fourth spacial dimension, and so arguing about whether one exists is a lot like arguing about the existence of God.

Quote: Originally posted by wg48  
While looking up some definitions of cosmological terminology I found the following text in a note titled: Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the universe by Tamara M. Davis and Charles H. Lineweaver. It was written 14 years ago. It’s amazing to me that this gobbledygook fairy tales stuff is still around. I guess its because its simpler to understand and teach in spite of the contradictions.

Oversimplifications aren't the same things as lies. If I explain how sunlight forms to a five-year-old, I have to choose between giving an answer that will hopelessly confuse him, or an answer that isn't 100% accurate but is as close to accurate as I think he can understand. The details can be elaborated on when he's old enough to understand them.

Physics professors are in the same predicament. With so many more students attending college than used to, you get a lot of dum-dums who you either hopelessly confuse, or make a judgment call regarding where to draw the line regarding simplification. The people who wrote this article seem to believe that some professors and authors have simplified too much. That's all.

I'm also glad to see that you're studying this stuff more. Knowledge is power, even if it's just the power to better articulate what, specifically is wrong with an oversimplified explanation of the standard model of the universe, without being wrong yourself.


https://www.youtube.com/watch?v=iGO12Z5Lw8s

Dodo's dont exist (now), how do we know unicorns have never existed? You could argue no fossil record, but then how come we still havnt found the missing link?

The fact its called the missing link means it is believed that there must be one, but as yet we havnt discovered it.

Once upon a time we lived on a flat earth, only we didnt did we.
until fairly recently things like the Bosen higgs didnt exist, and to be fair, if you believe in string theory etc then they didnt exist.

So take that further, in quantum physics and string theory, its possible for things to exist and not exist at the same time. Or it exists because we thought it into existence.

As for God, surely thats an open question until it can be proved one way or the other. The fact we dont know just means we dont have all the information.

How old are black holes? rare as rocking horse shit, except turns out every galaxy has at least one. So we have gone from not knowing they existed to finding them all over the place.

So do we have 3 dimensions or more than 3? I dont buy the argument that its the same as arguing god, as i said it wasnt that long ago not a single person would have entertained the idea of a black hole.

You cant prove god dosnt exist or 4 dimensions dont exist, the best you can manage is to say we dont know and dont have what it takes currently to prove or disprove.

I dont believe or disbelieve in 4 dimensions, i am open minded about it. I will remain open minded until its proved or disproved.

As for unicorns............how can you draw something that dosnt exist? If you draw a unicorn then what are you drawing? How do you know the excepted form of a unicorn is correct?

So i would argue your drawing isnt of a unicorn but of something other people tell you, represents a unicorn. So your taking someone word for it that a unicorn would indeed look like that.

Or the sheeple theory! :D

Dont be offended by anything I said, after all i cant see a reason to get upset about something you dont think even exists. If it helps, i dont think they are actually pink though ;)
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[*] posted on 9-11-2017 at 07:45


Quote: Originally posted by NEMO-Chemistry  

Dodo's dont exist (now), how do we know unicorns have never existed? You could argue no fossil record, but then how come we still havnt found the missing link?

The fact its called the missing link means it is believed that there must be one, but as yet we havnt discovered it.



You might want to read this:
https://en.wikipedia.org/wiki/Transitional_fossil#Missing_li...

Pay special attention to the last paragraph:

Quote:

"Missing link" is still a popular term, well recognized by the public and often used in the popular media.[59] It is, however, avoided in the scientific press, as it relates to the concept of the great chain of being and to the notion of simple organisms being primitive versions of complex ones, both of which have been discarded in biology.[5] In any case, the term itself is misleading, as any known transitional fossil, like Java Man, is no longer missing. While each find will give rise to new gaps in the evolutionary story on each side, the discovery of more and more transitional fossils continues to add to our knowledge of evolutionary transitions.[5][60]




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[*] posted on 9-11-2017 at 07:55


Quote: Originally posted by Melgar  



Oversimplifications aren't the same things as lies. If I explain how sunlight forms to a five-year-old, I have to choose between giving an answer that will hopelessly confuse him, or an answer that isn't 100% accurate but is as close to accurate as I think he can understand. The details can be elaborated on when he's old enough to understand them.

Physics professors are in the same predicament. With so many more students attending college than used to, you get a lot of dum-dums who you either hopelessly confuse, or make a judgment call regarding where to draw the line regarding simplification. The people who wrote this article seem to believe that some professors and authors have simplified too much. That's all.

I'm also glad to see that you're studying this stuff more. Knowledge is power, even if it's just the power to better articulate what, specifically is wrong with an oversimplified explanation of the standard model of the universe, without being wrong yourself.


So you categorize children in the same group as physics students!!! No wonder you think its ok the pass off fairy tales to both.

To suggest I am studying the subject would be an oversimplification. I am attempting to produce a version of the expanding space animation shown below. I don’t want to oversimplify it so I want to get the dimensions and expansion rate unoversimplified. The hope is it may help undo some oversimplifications. But apparently I have oversimplified the task LOL.

Yes oversimplified sounds much better than wrong, false, fake incorrect or lie. You could also use misunderstanding, inaccurate and famously in the UK, economical with the truth. Like the speed of light in SR, in my frame BS is BS and its never good in the long term to BS children, physics students or anyone else.

cphotons.gif - 146kB
from http://www.astro.ucla.edu/~wright/photons_outrun.html

Edit: added gif reference, move a pic to correct thread




[Edited on 9-11-2017 by wg48]
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[*] posted on 9-11-2017 at 11:01


@NEMO I'm almost entirely sure that you wrote that with the intention to create as much confusion as possible.

However, since we're floating theories here, how about I float my "Big Flush" theory?

In sci-fi, wormholes are a popular concept, because they allow for travel between dimensions. But "real" theoretical wormholes could really only exist in a really massive black hole, where spacetime is stretched to its tearing point. Nobody has any idea how much mass it'd take to open up a hole in spacetime. Except me! See, I've theorized that if a black hole gets big enough, it tears open a tiny hole in spacetime, and flushes its contents down the hole, only closing when its mass is no longer enough to keep the hole open. Where does that mass go though? Nowhere. It's flung outside of time and space, where it quickly establishes order in its own right, as a new universe. This theory is actually testable. Wormholes should not be able to exist in our universe, because its combined mass isn't even enough to tear spacetime. And if anyone ever figures out how much mass is needed to warp spacetime enough to tear it, and other wormhole dynamics, it would correspond to our universe having been flushed through one.

Or how about my "Mxyzptlk" theory?

Mister Mxyzptlk is a Superman villain who lives in the fifth dimension. There, things happen for no reason. It's rather chaotic, but its residents have adapted. Effects don't necessarily have causes. Mister Mxyzptlk likes to come to our dimension (he's a criminal in his own dimension too) and wreak havoc by making it more like his own. Superman can't hurt him physically, though. To make him go back to his own dimension, Superman has to trick him into saying his name backwards. Anyway, it's already agreed that time is the fourth dimension, which is why Mister Mxyzptlk's dimension is the fifth one. However, if he lives in the fifth dimension and can come to our dimension, then that means that our universe exists within his. And since cause and effect aren't linked in the fifth dimension, then there's every reason to believe that a universe where cause and effect ARE linked, could come into existence for no reason at all. You may be wondering where the fifth dimension came from, but that implies a cause and effect, neither of which exist in the fifth dimension. Duh.




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[*] posted on 9-11-2017 at 14:42


X, Y, Z, Time, Gravity, Electric, Magnetic ... Oh ! and maybe Energy. Forgot that one.

That's 7 (or 8) dimensions already.

Which one is the 5th dimension ?




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[*] posted on 9-11-2017 at 14:57


Quote: Originally posted by Melgar  
@NEMO I'm almost entirely sure that you wrote that with the intention to create as much confusion as possible.

However, since we're floating theories here, how about I float my "Big Flush" theory?

In sci-fi, wormholes are a popular concept, because they allow for travel between dimensions. But "real" theoretical wormholes could really only exist in a really massive black hole, where spacetime is stretched to its tearing point. Nobody has any idea how much mass it'd take to open up a hole in spacetime. Except me! See, I've theorized that if a black hole gets big enough, it tears open a tiny hole in spacetime, and flushes its contents down the hole, only closing when its mass is no longer enough to keep the hole open. Where does that mass go though? Nowhere. It's flung outside of time and space, where it quickly establishes order in its own right, as a new universe. This theory is actually testable. Wormholes should not be able to exist in our universe, because its combined mass isn't even enough to tear spacetime. And if anyone ever figures out how much mass is needed to warp spacetime enough to tear it, and other wormhole dynamics, it would correspond to our universe having been flushed through one.

Or how about my "Mxyzptlk" theory?

Mister Mxyzptlk is a Superman villain who lives in the fifth dimension. There, things happen for no reason. It's rather chaotic, but its residents have adapted. Effects don't necessarily have causes. Mister Mxyzptlk likes to come to our dimension (he's a criminal in his own dimension too) and wreak havoc by making it more like his own. Superman can't hurt him physically, though. To make him go back to his own dimension, Superman has to trick him into saying his name backwards. Anyway, it's already agreed that time is the fourth dimension, which is why Mister Mxyzptlk's dimension is the fifth one. However, if he lives in the fifth dimension and can come to our dimension, then that means that our universe exists within his. And since cause and effect aren't linked in the fifth dimension, then there's every reason to believe that a universe where cause and effect ARE linked, could come into existence for no reason at all. You may be wondering where the fifth dimension came from, but that implies a cause and effect, neither of which exist in the fifth dimension. Duh.


Wrote it with a smile, i have no idea about space, black holes, worm holes(except garden ones), or space stretching.

To me it is what it is, i find all the theories fascinating, but honestly i wouldnt know where to start to even begin to try and understand how it all works.

But I am offended about unicorns and the easter bunny ;)
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[*] posted on 9-11-2017 at 22:01


Quote: Originally posted by NEMO-Chemistry  
Wrote it with a smile, i have no idea about space, black holes, worm holes(except garden ones), or space stretching.

To me it is what it is, i find all the theories fascinating, but honestly i wouldnt know where to start to even begin to try and understand how it all works.

But I am offended about unicorns and the easter bunny ;)

Have you ever heard of the "Gish Gallop"? It's a technique used by this Australian young-earth creationist to throw as much crap out there in as short of a time as possible, to make it impossible to refute all the crap in any reasonable time frame. It's essentially "starting ten fires in ten minutes", and then making it someone else's job to put them out. Well, I just thought you should know that your post would make even the great Duane Gish jealous. ;)

[Edited on 11/10/17 by Melgar]




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[*] posted on 10-11-2017 at 09:21


Quote: Originally posted by aga  
X, Y, Z, Time, Gravity, Electric, Magnetic ... Oh ! and maybe Energy. Forgot that one.

That's 7 (or 8) dimensions already.

Which one is the 5th dimension ?

First off, energy isn't a dimension. It's a quantity, equal to mass times the speed of light squared. So matter and energy are theoretically interchangeable. Though, to do it directly would require antimatter. Gravity can be thought of as a field or a force that exists within the three spatial dimensions (and time, of course). Not a dimension in its own right. There are four primary forces in our universe: gravity, electromagnetism, the strong force (holds protons together in an atom's nucleus, so their electrostatic repulsion doesn't send them flying apart), and also the weak force, which has something to do with neutrinos and isn't especially important to understand unless you care a lot about subatomic particles.

Magnetism and electricity are actually the same force, electromagnetism, but magnetic fields and electrical fields are perpendicular to each other. Moving an electrical charge creates a magnetic field, and moving a magnetic field will exert a force on electrical charges. You know how the sun has all these magnetic storms on it, and solar flares that are tightly bound to magnetic field lines? Have you ever wondered why? After all, the sun is almost entirely made of hydrogen and helium, neither of which we think of as being strongly magnetic. Well, it's because the sun is a plasma, made of ionized gas. And ions are charged. So when an ion moves, it generates a magnetic field. And since the sun is constantly churning, all those ions generate enormous magnetic fields, sometimes even strong enough to cause EMP-like problems on Earth.




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[*] posted on 10-11-2017 at 11:48


Quote: Originally posted by Melgar  

First off, energy isn't a dimension. It's a quantity, equal to mass times the speed of light squared ... Gravity can be thought of as a field or a force ... Magnetism and electricity are actually the same force ...

Personally i disagree with all of that, apart from possibly the energy thing.

How the dimensions appear to us (and can be quantified/analysed) is entirely defined by our existence in the first four, which is all i am trying to convey.

Basically we cannot usually see or imagine much beyond what we evolved in, which does not make that the Absolute Truth about reality.

I missed my meeting around Proxima Centuri by the way.




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[*] posted on 10-11-2017 at 13:16


But I guess the point is, you can quantify a field in terms of its strength, but you can't describe a dimension as having strength. You might be thinking about how "gravity wells" are sometimes drawn as though they exist in another dimension, but that's really just a way of depicting a field that perhaps isn't the most accurate. A more accurate depiction might be as a vector field:

ex27b_01.png - 10kB

Electromagnetism is even more confusing because of the perpendicular electric and magnetic field lines, but it's pretty much a proven fact that electricity and magnetism are inseparable, and are just different manifestations of the same force.

Have you ever read Richard Feynman's "Cargo Cult Science" speech? It's very good, and I read it several times a year just to remind myself what science should be like, even if it doesn't always meet these standards. I highly recommend everyone in this thread read this, actually:

http://www.sciencemadness.org/talk/viewthread.php?tid=76734&...

I should probably ask for permission to edit the wiki or something, so I can add this to it. It's somewhere else on the web, but there are random spaces missing in the text that makes it hard to read so I edited it, but then never quite found a good home for it.




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[*] posted on 10-11-2017 at 13:54


Just U2U zts16, who founded the excellent wiki (if i recall correctly) and access is granted, if granted.

Your notions of what energy, magnetism, electricity and gravity are, could quite easily be incorrect.

I Know that mine are totally wrong, as i can only observe/measure their Effects based on my own reality-references, which i know cannot be their entire existence.




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[*] posted on 10-11-2017 at 15:09


Quote: Originally posted by Melgar  
Quote: Originally posted by NEMO-Chemistry  
Wrote it with a smile, i have no idea about space, black holes, worm holes(except garden ones), or space stretching.

To me it is what it is, i find all the theories fascinating, but honestly i wouldnt know where to start to even begin to try and understand how it all works.

But I am offended about unicorns and the easter bunny ;)

Have you ever heard of the "Gish Gallop"? It's a technique used by this Australian young-earth creationist to throw as much crap out there in as short of a time as possible, to make it impossible to refute all the crap in any reasonable time frame. It's essentially "starting ten fires in ten minutes", and then making it someone else's job to put them out. Well, I just thought you should know that your post would make even the great Duane Gish jealous. ;)

[Edited on 11/10/17 by Melgar]


Thank you, thats the nicest thing anyone has said to me in ages :D
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[*] posted on 11-11-2017 at 04:26


So here is my gif. It my first cut at the animation. Its created in Mathcad. I started with in 3D but because of the way Mathcad plots in 3D that was very messy and slow with a million data points. Then I tried x y plot again messy getting the radial motion. Eventually I switched to a 2D polar plot. That made the radial motion trivial. Animated plots can be recorded in an avi file. Then converted to a gif. Irritatingly it took me ages to create an inverse hyperbolic tan function for a two pi range and a uniform random distribution of galaxies in 2D

Its a sequence of representations of a flat (insignificant matter energy content) universe 13 billion years old with increasing a Hubble constant starting at zero and increasing in value to about the same as our present universe’s Hubble constant. The earth is stationary at the centre of the diagram and galaxies/cluster are represented by black dots.

The representation is slice of our universe about one light day deep. The radius of the initial slice is 100 billion light years. It contains no distortions it’s a scale model. It shows the compression (not an optical effect) caused by motion (SR). The inner circle has a radius of 13 billion light years and approximately the present position of our universe's horizon. Its similar to the horizon of a black hole except that it recedes from us at light speed. The first frame is a static universe with a Hubble constant of zero..

The key points are;

If the universe expanded from a single point then even a universe containing an infinite number galaxies each receding from its neighbour is contained within the horizon with most of them compressed near the horizon. In our stationary frame of reference even an infinite sized expanding universe is finite.

If we where magically transported to one of the planets of one of the galaxies near our horizon and we looked back we would see the same picture we see from out planet.




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[*] posted on 11-11-2017 at 13:51


Yeah, exactly. I'm glad we're finally in agreement!

Although I was aware that this phenomenon wouldn't make galaxies able to "outrun light", it would have been difficult for me to explain to anyone why. Looking at those animations, I came up with a way to explain it finally: as the light gets further from us, the expansion of the universe between us and the light becomes significant, and the distance between us and the photon actually is increasing faster than the speed of light.

Like if two cars are driving in opposite directions, and one is going the speed limit in Europe, and the other is going the speed limit in North America. However, they're moving apart at GREATER than their combined local speeds, due to the fact that the continents are moving apart. (This added velocity is similar to the speed with which fingernails grow) Someone who doesn't know much about astrophysics could probably wrap their heads around this analogy, as long as it was followed up with an insistence that this expansion is uniform throughout the universe.




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[*] posted on 11-11-2017 at 13:57


Did i post something yesterday that got deleted ?

I was very drunk (as now), however i feel it was important.




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[*] posted on 16-11-2017 at 07:59


While playing around with Mathcad I considered the following: Consider two linear particle accelerator arranged back to back such that the particles are accelerated from a common point. In addition assume that the particles are accelerated in closely spaced bunches such that the velocity between each bunch in the initial frame of the two bunches is the same velocity between each adjacent pair of bunches. Note due special relativity (SR) this would require a progressively increasing acceleration force (in the frame of the accelerators) as the mass of the particles increases as their velocity increases again in the frame of the accelerators. So we have a long line of bunches of particles with each pair of bunches separating at a constant velocity in their frame.

This is similar to the way galaxies recede from each other in our isotropic expanding universe. So I should be able to create a 1D CDM model or metric to describe the motion of the bunches of particles. To simplify the metric I only considered infinitesimally small mass energy density (no gravity) and no dark energy (constant H) as I am principally concerned with how SR is handled in the metric. Meaning I can calculate the relativistic red shift of the bunches using SR and compare the result with the result from the metric. When I did this I was initially only able to get identical results for v less than c ie slow speeds. On inspection the two different methods are not mathematically equivalent and cannot produce the same red shift for velocities approaching c or supraliminal velocities (the frame of particle bunch or galaxy). As I believe SR is applicable in both cases (its accuracy has been tested exhaustively at speeds close to c and at large distances) I must have made a mistake.

On careful reading one of the notes I posted a link to, the problem is in the cosmological definition of red shift. Most cosmologists use the low speed definition of red shift. The detailed explanation is in the mathematical section with its discussion near the end of the note I referenced. In effect most cosmologists ignore SR, which I suspect is a major contribution to the expanding space myth.

Bizarrely its because SR is ignored they assume fake supraliminal motion of distant galaxies then because that violates SR’s restriction on the maximum velocity of an object, SR is then used to justify the belief that it must be space that is expanding ???

PS I was using the term proper distance incorrectly. I should have been using the term co-ordinate distance. Proper distance (fake) is the x,y and z of the CDM model.

Here are good, at least understandable to me, definitions of the various terms. Its also humorously (Star Trek) explains the supraliminal thing and uses word fake.

https://thespectrumofriemannium.wordpress.com/tag/coordinate...

The myth has bugged me for about 50 years I think I am finally done with it, back to my animations.

[Edited on 16-11-2017 by wg48]
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[*] posted on 10-1-2021 at 05:19


I received the following question via U2U:

"When you say you don’t believe in expanding space are you saying that there are no galaxies that are appearing to move away from each other at numerous times the speed of light?

You are a very knowledgeable guy on here and if you don’t believe that then I’m interested in why? I’ll definitely learn something if you reply."

I replied with the note below. I thought my reply was succinct explanation that may be of interest to others. I did add slightly to the reply.

Briefly it depends on what you mean by "appearing to move away from each other at numerous times the speed of light?".

In relativity you have to be very careful in specifying velocities. For example it is possible to observe the microwave background radiation with a huge red shift (one of the largest red shifts observable if not the largest) indicating its moving away from the earth at almost the speed of light (using relativistic red shift calculation)

In the opposite direction its also possible to observe the microwave background radiation moving away from the earth at almost the speed of light. That is also true for some very distant galaxies. So you could say that those very distant galaxies are moving away from each other at almost twice the speed of light. But you can not use simple arithmetic to add velocities that are near the speed of light as explained by special relativity.

So an observer on one of those distant galaxies could observe our galaxy moving away from them at almost the speed of light. They could also observe a distant galaxy on the opposite side of our galaxy but they would be observed that distant galaxy with a red shift only slightly greater than the red shift of our galaxy indicating its velocity was closer to the speed of light than our own galaxy but not at almost twice the speed of light.

In fact it is impossible for an observer to optically observe anything moving away from that observer at a speed greater than the speed of light as that would imply the light was traveling at a speed greater than the speed of light.

The term "expanding space" is frequently used to explain how galaxies can be moving at speeds greater than the speed of light. Usually along the lines of "it not that the galaxies are moving faster than light, which is impossible, its space is expanding faster than light and as space is not an object its not subject to the light speed limit". It just a convenient and simple, but erroneous explanation, in many popular science articles and even by some astronomers who should no better.

I should add that the above refers only to observable galaxies or objects.




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[*] posted on 8-8-2022 at 19:23




While attempting to swot up on the Friedmann–Lemaître–Robertson–Walker cosmology model I discovered the attached paper. It supports my view that expanding space is mythical. It explains in a much better way than I did that the apparent (mythical) superluminal velocity of distant galaxies results from the definition of distance used. Here is the conclusion of the paper:

Conclusions
In this paper, as a counterexample to the idea of expanding space, we have studied the dynamics of the empty model. We have shown that the cosmological redshift is there a result of the real motion of the source, i.e., a Doppler shift. We have verified that the local temperature of the CMB photons at a source of redshift z is a factor of (1 + z) greater than its present value, in agreement with GR. We have shown that the recession velocities of distant galaxies are only apparently superluminal, due to the adopted definition of distance in cosmology and the effect of special-relativistic time dilation. Alternatively defined, inertial velocities are subluminal. The effect of time dilation is also responsible for infinite distance to the particle horizon in this model. Specifically, the distance is infinite because the proper time of a fundamental observer moving with the speed of light does not flow, so it never acquires a non-zero value, necessary to perform the measurement of the distance. (It is always ‘too early’ to send any communication photons.) The particle horizon exists (i.e., the distance to it is finite) for models with a period of initial deceleration, i.e., for which Ωm > 0.

The empty model shares all properties of the Friedman models, that are commonly considered as an evidence for general-relativistic expansion of space (see Section 1). However, in the empty model these properties are shown to be in agreement with SR and are fully explicable as the effects of real, relativistic motions in space. Therefore, there is at least one Friedman model, in which expansion of space, in detachment from expanding matter, is an illusion. Actually, there is a whole class of such models: with the mean matter density much smaller than the critical density, and vanishing cosmological constant. In these models (at least since some instant of time) expansion is approximately (but with arbitrary accuracy) kinematic, and spacetime is approximately the static Minkowski spacetime. The empty model is an asymptotic state of any open model with ΩΛ = 0. Therefore, in any such universe, during its evolution, expanding space should somehow, mysteriously, disappear. The proponents of expansion of space must be able to describe this process of disappearance. The simplest scenario for disappearing expanding space, that comes to the mind of the author, is that it has never existed. There is neither absolute space, nor expanding space. All that matters is the cosmic substratum and its relative motions. A truly Buddhist enlightenment.

From Attachment: counter-example-0601171.pdf (147kB)
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I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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