What exactly is "spin"?

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Re: What exactly is "spin"?

Postby PhysBang » Wed Mar 24, 2010 2:23 am

Jakob wrote:Yes, there were intended for you... thanks for trying to answer. But... this is all extremely vague, not really anything of substance. Farsight may be lying, but so far I have to just take his critics at their words. They might be totally in the dark. Which is how it appears to me, because all I get is references to links and comments like 'there are many ways things happen. But I won't get into the mathematical details.' Vaguer than vague.

I hope you note that Farsight is also vague on mathematical details. He is someone that, in his own words, refuses to develop mathematical details.

The reason that my answers may be a bit vague is because Farsight is literally so wrong that he is not really talking about physics. When you ask a question about what alternatives to his theories could be, one can only point to the work that actual physicists do because Farsight refuses to actually produce specific predictions of his theory. If one criticizes Farsight on a particular point, he dodges the questions by discussing something else or by claiming that he means something else. He can't be pinned down because there is really no content to his theory.

I ask him about the rotation curves of galaxies because that is one specific prediction that he has made (perhaps the only one). He is saying that if one calculated the rotation curves of galaxies using general relativity, then there would be no need for the hypothesis of dark matter. Now he has never actually shown how to do this (and there are many papers that actually do this calculation and show that we still need to hypothesize dark matter). That Farsight refuses to support the one prediction he has ever made is a bad sign for his ability to produce a real physical theory.
Anyway, I was under the impression that it is the rotation of galaxies suggest a much greater mass that what is measured, that suggests dark matter. I always found this a bit of a stretch. I am open to the suggestion there is a more elegant solution.

The rotation curves of most galaxies suggests that the visible part of galaxies are surrounded by a much larger distribution of mass. So too does the way that light bends around galaxies. So too do the orbits of galaxies around each other. So too does the bending of light around groups of galaxies.

Looking at the way that galaxies form into clusters in general suggests that there is some sort of dark matter. So too does the behaviour of particles in the early universe.

These are all research projects with a lot of physicists and astronomers making careful observations and calculations. Almost all of these scientists use general relativity. Despite this, Farsight claims that if we used general relativity correctly, we would not have a need for dark matter. So Farsight is saying that all of these scientists are wrong, though he will not show anyone exactly how these scientists are wrong. Even on a message board with dozens of professional astronomers and astrophysicists, Farsight could not produce the relevant calculations.

Farsight does seem good at offering confident statements. Unfortunately, science is often not as confident as we would wish it to be. Additionally, Farsight never delivers on the evidence that his confidence suggests.
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Re: What exactly is "spin"?

Postby Anthem » Wed Mar 24, 2010 2:42 am

PhysBang = correct.
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Re: What exactly is "spin"?

Postby Jakob » Wed Mar 24, 2010 4:28 pm

Farsights point is that Einsteins statement that space is not homogenous does away with the necessity of dark matter.
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Re: What exactly is "spin"?

Postby Jakob » Wed Mar 24, 2010 8:56 pm

The argument for dark matter is curiously similar to the argument for God. There's a phenomenon we can't account for, so we posit an invisible entity to account for it. That entity is subsequently proven by measuring the phenomenon again, and concluding it is consistent with itself. I don't see any proof anywhere except that we're lacking knowledge about the relation between gravity and mass on a large scale. Given that on a very small scale, certain laws do no longer apply, shouldn't the possibility for a similar discontinuity on the other end of the scale at least be considered?
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Re: What exactly is "spin"?

Postby PhysBang » Wed Mar 24, 2010 9:05 pm

Jakob wrote:Farsights point is that Einsteins statement that space is not homogenous does away with the necessity of dark matter.

Yes, but what does that mean?

Einstein believed that space on the large-scale average was homogeneous. We know that because he endorsed a cosmological model in which this was the case both before and after he made the claim that Farsight quotes. So what did Einstein mean when he said that space is not homogeneous? Well, he meant pretty much what he said afterwards, which is that in order to explain gravity, we have to look to the distribution of matter in spacetime and use this to determine the geometry of spacetime. (And this is what every relativistic cosmological model does and what every astronomer who measures dark matter using relativistic means does also.)

But what does Farsight mean when he says that inhomogeneous space will do away with the need for dark matter? Nobody knows. I suspect not even Farsight knows. If we could see an actual calculation of how to calculate a galaxy rotation curve "the Farsight way" then we would have an idea of what he means. But unlike every scientific paper on dark matter, Farsight refuses to actually demonstrate the relationship between measurements of gravitational phenomena and dark matter.

Physics is more than the ability to state things confidently. Physics involves the ability to make claims about physical systems that we can either use in application or that we can support with observations that include measurements. Farsight has never made such a claim.
The argument for dark matter is curiously similar to the argument for God. There's a phenomenon we can't account for, so we posit an invisible entity to account for it. That entity is subsequently proven by measuring the phenomenon again, and concluding it is consistent with itself. I don't see any proof anywhere except that we're lacking knowledge about the relation between gravity and mass on a large scale. Given that on a very small scale, certain laws do no longer apply, shouldn't the possibility for a similar discontinuity on the other end of the scale at least be considered?

There is a difference between the argument for dark matter and the argument for god: measurement evidence and the properties of dark matter. While god can have any properties, dark matter cannot. And we can measure the properties of dark matter in many, many ways. And people do consider the possibility that a change in the way gravity works might change the need for dark matter. So far, these other projects have failed.

Note that Farsight claims that he is not trying to change gravitational theory. He seems to be saying that if people calculated correctly, then there would be no need for dark matter or an alternative to standard gravitational theory. Yet he refuses to demonstrate how to calculate correctly.
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Re: What exactly is "spin"?

Postby Jakob » Thu Mar 25, 2010 4:04 pm

I will let Farsight counter these challenges if he feels the need to - dark matter isn't really the focus of this thread anyway - I think I'll just order his book and form my judgment based on that.

Didn't Einstein have had a position on Dark matter himself, by the way? And did he not propose this cosmological constant which now somehow comes back as dark energy, responsible for the expansion of the universe? I know it's not the same, but the theory of dark matter existed when he was still alive, didn't it?
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Re: What exactly is "spin"?

Postby PhysBang » Thu Mar 25, 2010 7:57 pm

Jakob wrote:I will let Farsight counter these challenges if he feels the need to - dark matter isn't really the focus of this thread anyway - I think I'll just order his book and form my judgment based on that.

If you are interested in physics, I would recommend that you start with more basic books on the subject.
Didn't Einstein have had a position on Dark matter himself, by the way? And did he not propose this cosmological constant which now somehow comes back as dark energy, responsible for the expansion of the universe? I know it's not the same, but the theory of dark matter existed when he was still alive, didn't it?

The problem that there might be a matter that cannot be seen was considered since at least the 1930s, but there was no evidence for a need for dark matter until after Einstein's death.
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Re: What exactly is "spin"?

Postby Jakob » Fri Mar 26, 2010 1:30 am

Don't worry about me, PhysBang. Go chase Farsight, he must be somewhere spreading his false propaganda.
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Re: What exactly is "spin"?

Postby Jakob » Fri Mar 26, 2010 1:43 am

And people do consider the possibility that a change in the way gravity works might change the need for dark matter. So far, these other projects have failed.

Or maybe you could point me to literature about this?
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Re: What exactly is "spin"?

Postby Jakob » Fri Mar 26, 2010 2:06 am

PB - I'm pretty annoyed here - you act as if you've actually said or explained something, where in fact you've only accused Farsight of lying, and made some statements about unnamed models and sources when I asked you to show that he is. Look at what you said.
Einstein believed that space on the large-scale average was homogeneous.

Source?
We know that because he endorsed a cosmological model in which this was the case both before and after he made the claim that Farsight quotes.

Specification? Source?
So what did Einstein mean when he said that space is not homogeneous? Well, he meant pretty much what he said afterwards, which is that in order to explain gravity, we have to look to the distribution of matter in spacetime and use this to determine the geometry of spacetime.

Source?
(And this is what every relativistic cosmological model does and what every astronomer who measures dark matter using relativistic means does also.)

Aha
But what does Farsight mean when he says that inhomogeneous space will do away with the need for dark matter? Nobody knows. I suspect not even Farsight knows

It's very obvious what he means.
. If we could see an actual calculation of how to calculate a galaxy rotation curve "the Farsight way" then we would have an idea of what he means.

Of course we can't, because if space is not homogenous, we don't have any math to work with.
But unlike every scientific paper on dark matter, Farsight refuses to actually demonstrate the relationship between measurements of gravitational phenomena and dark matter.

That makes no sense at all, the relation between gravitational phenomena and dark matter is only the hypothesis that there is a relation.
Physics is more than the ability to state things confidently.

Very confidently stated!
Physics involves the ability to make claims about physical systems that we can either use in application or that we can support with observations that include measurements.

Very confidently stated! Never mind that you say nothing at all!
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Re: What exactly is "spin"?

Postby Farsight » Wed Apr 07, 2010 9:36 pm

Jakob: I find it very sad that some people dismiss and deny what Einstein actually said. They won't enter into a sincere discussion, they won't furnish evidence to back up their assertions, they do not hesitate to attempt to discredit, and they have a sneering arrogance that treats the public with utter contempt. There's an elitist aspect to all this, it's been hampering scientific progress, and it's got to stop.
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Re: What exactly is "spin"?

Postby PhysBang » Thu Apr 08, 2010 2:21 am

Jakob wrote:
Einstein believed that space on the large-scale average was homogeneous.

Source?

Relativity, by Albert Einstein

One could see also, for example, http://scienceworld.wolfram.com/physics ... Model.html
Or wikipedia: http://en.wikipedia.org/wiki/Static_universe
We know that because he endorsed a cosmological model in which this was the case both before and after he made the claim that Farsight quotes.

Specification? Source?

See above.
So what did Einstein mean when he said that space is not homogeneous? Well, he meant pretty much what he said afterwards, which is that in order to explain gravity, we have to look to the distribution of matter in spacetime and use this to determine the geometry of spacetime.

Source?

See everything ever written by Einstein after 1915, in which he actually explained the use of spacetime with very detailed mathematical physics.
But what does Farsight mean when he says that inhomogeneous space will do away with the need for dark matter? Nobody knows. I suspect not even Farsight knows

It's very obvious what he means.

Really? Could you use Farsight's idea to calculate the rotation curve of a galaxy? Even Farsight can't do this.
. If we could see an actual calculation of how to calculate a galaxy rotation curve "the Farsight way" then we would have an idea of what he means.

Of course we can't, because if space is not homogenous, we don't have any math to work with.

There are an infinite number of solutions to the Einstein Field equations that have an inhomogeneous distribution of matter and energy. Most applications of general relativity use an inhomogeneous distribution of matter and energy. These solutions use mathematics and they are what actually convinces physicists that general relativity is correct. Einstein did not succeed because he was good at prose.
But unlike every scientific paper on dark matter, Farsight refuses to actually demonstrate the relationship between measurements of gravitational phenomena and dark matter.

That makes no sense at all, the relation between gravitational phenomena and dark matter is only the hypothesis that there is a relation.

Yes, but that hypothesis is backed up by specific predictions and by measurements. Farsight has nothing of the sort.
Physics involves the ability to make claims about physical systems that we can either use in application or that we can support with observations that include measurements.

Very confidently stated! Never mind that you say nothing at all!

I am not the one telling you that everything in every physics textbook is wrong. Farsight is setting himself up as the saviour of physics. If you want to find out if he is correct, you should read some relevant physics texts. You will soon discover how wrong Farsight is and how I have been saying merely the obvious.
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Re: What exactly is "spin"?

Postby Farsight » Fri Apr 09, 2010 7:27 pm

Better still, read what Einstein said. See viewtopic.php?f=4&t=171501 and follow the links. PhysBang dismisses Einstein.
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Re: What exactly is "spin"?

Postby Jakob » Mon Mar 28, 2011 2:12 pm

PhysBang wrote:I am not the one telling you that everything in every physics textbook is wrong. Farsight is setting himself up as the saviour of physics. If you want to find out if he is correct, you should read some relevant physics texts. You will soon discover how wrong Farsight is and how I have been saying merely the obvious.

The assumption that when someone is "saying merely the obvious", we should expect truth to be revealed, is an exemplary example of the stupidity behind common sensical thinking.

Was Einstein ever "saying merely the obvious"? Of course not. There is nothing obvious about science, or about any insightful thought. The obvious is the meaningless and mindless shell of social consensus - Insight is what breaks through the obvious.
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Re: What exactly is "spin"?

Postby Jakob » Fri Apr 01, 2016 3:07 pm

So, where do we stand on this, now?
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Re: What exactly is "spin"?

Postby Amorphos » Fri Apr 01, 2016 6:23 pm

There is nothing obvious about science, or about any insightful thought.


That's an interesting notion! I don't even know why the world isn't obvious, so I wont butt into your debate. Better if all debaters were up with the science, then surely the original topic could be discussed from a higher vantage point.
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Re: What exactly is "spin"?

Postby Jakob » Sun Apr 03, 2016 5:24 pm

Amorphos wrote:
There is nothing obvious about science, or about any insightful thought.


That's an interesting notion! I don't even know why the world isn't obvious, so I wont butt into your debate. Better if all debaters were up with the science, then surely the original topic could be discussed from a higher vantage point.

Farsight has a towering vantage point it seems to me.

The obviousness question: obviously scientific theorems are never obvious. It would not require brilliant men to produce them otherwise. It would just all be speaking for itself and the world would be fully understood by anyone who looked at it.
Not so.

And, obviously, 'scientific models' and 'the world' aren't equal notions.

We are in the world, of the world, it can not possibly be expected that the nature of the world is fully apperceptible to anyone except the most fully realized, rugged , happy and powerful expriencer of it.

Obviously. (;
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Re: What exactly is "spin"?

Postby Amorphos » Sun Apr 03, 2016 9:22 pm

I see. To get a world which is a simple and easily explainable one ~ something akin to a child's view, reality would have to arrive at that somehow. Then you have to get from infinity to the finite, whatever versions of the world we have. I can't see any way to do that without involving abstracts in both form and pattern. Ergo you don't get an obvious world without metaphysical foundations. Somewhere in that is the connectivity by which things interact, then the abstract [like mind] connects with an impression of the derivative world. That impression is the experienced world of objects ~ the 'obvious' world.
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Re: What exactly is "spin"?

Postby barbarianhorde » Sun Mar 19, 2017 1:34 am

Farsight wrote:Better still, read what Einstein said. See phpbb/viewtopic.php?f=4&t=171501 and follow the links. PhysBang dismisses Einstein.


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Re: What exactly is "spin"?

Postby barbarianhorde » Sat Apr 01, 2017 10:23 pm

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