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View Poll Results: Could there be a connection between space time and the so-called "Darkness"?

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Thread: A connection Between Space-time and Dark matter/Energy

  1. #101  
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    Quote Originally Posted by Cyberia View Post
    Despite all the talk of redshifts and recession, we actually have no moving pictures of stars against backgrounds to back them up, to show that they move exactly the speed the redshifts claim they do.
    Since redshifts are measurements of recession, it would be sheer idiocy to attempt to match them to movement against a background. Since cosmological redshifts arise from time dilation, not from motion, they can be matched to other measurements of time dilation. This was done in Goldhaber et al. (The Astrophysical Journal, 558:359-368, 2001 September 1) and in Blondin et al. (The Astrophysical Journal, 682:724-736, 2008 August 1) each using a different method.

    Vague claims about I ignore the details.
    No, specific claims. The shell theorem applies to situations where there is a spherically symmetric distribution of matter. It is an example of how a particle will not feel a net attraction to the greater amount of matter near it.
    We know how gravity works so if there is 6 times as much DM as LM, then DM holds sway, as in stopping the LM flying out of the galaxy. And going where the DM drags it.
    Exactly: that's why we see galaxies in the shapes that we do and why they move like they do.
    Really? How do we prove that sugar always makes coffee taste sweet?
    The tongue reacts to sugar, salt, acid and savory tastes. If you have a tongue, you will detect sugar as sweet and the more sugar, the more sweeter something will taste.
    How do you know that it's the sugar that it making the sweet taste?
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  2. #102  
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    Quote Originally Posted by PhysBang View Post
    Quote Originally Posted by JoeRand View Post
    Apples falling, the Moon orbiting, planets orbiting, yes? But dark matter is a thing or things, not a force. I never meant to imply the existence of gravity requires laboratory confirmation.
    If you are willing to accept the observations of the moon as "direct evidence" of how gravity works, then why not observations of galaxies and the stars within them?
    That sounds like MOND thinking, does it not? If we assume what we observe is a direct observation of all there is, or at least all that is relevant to the problem at hand, then we would simply modify our law of gravity to change with the scale of the matter configurations observed, without invoking unknown and undetectable forms of matter and energy to explain their changing patterns of motion. It is because we look for laws that are universally valid that such an idea bothers us, and we instead go around the directly observable and imagine there is dark matter and energy filling in the necessary gaps.

    Considering only small proximate bodies, we have never before needed to invoke invisible matter and energy as contributing factors to describe their motion. Naturally, there are "invisible forces" (the given order of the universe), but that is a fundamental self-evident assumption. That is different from inferring undetectable matter and energy exist and must be influencing everything, in order to account for the unexpected motion observed in large distant bodies. So, I am not doubting the observations of galaxies and the stars within them. I am holding judgement as to the cause of the apparent discrepancy in their motion. Or to look at it another way, you can conceivably have a small piece of direct evidence of something. It does not necessarily illuminate the big picture on its own, though it may make sense of most of what we can at present conceive. Gravity may behave differently at different scales, provided that the new description is compatible with the description we already know to be accurate. Or dark matter may yet be uncovered by experimental verification. Or another possibility accounts for the phenomenon.
    Last edited by JoeRand; October 18th, 2011 at 03:09 PM.
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  3. #103  
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    Quote Originally Posted by JoeRand View Post
    That sounds like MOND thinking, does it not? If we assume what we observe is a direct observation of all there is, or at least all that is relevant to the problem at hand, then we would simply modify our law of gravity to change with the scale of the matter configurations observed, without invoking unknown and undetectable forms of matter and energy to explain their changing patterns of motion. It is because we look for laws that are universally valid that such an idea bothers us, and we instead go around the directly observable and imagine there is dark matter and energy filling in the necessary gaps.
    Why must you misinterpret what I write?

    Considering only small proximate bodies, we have never before needed to invoke invisible matter and energy as contributing factors to describe their motion.
    You should acquaint yourself with the history of physics.
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  4. #104  
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    PhysBang. Redshifts measure a loss of energy by a photon since they cannot lose speed. While it is true that we can measure objects in space moving away from us by this method, we can also see how gravity redshifts photons too.

    Why is it sheer idiocy to match the redshift of a moving object to the distance it actually moves over time to see if it has no other components? Surely that is how science is done rather than just making assumptions?

    Cosmological time dilation only works on quasars back to six billion light years away. After that it fails totally. So another explanation is needed. Strange how with all these people checking every day, including twice on Sundays, that the BB works, failed to notice this till very recently.

    Strange how we have a spherical shape with the shell theorem but a fairly flat spiral galaxy. Surely the galaxy should be spherical too, and since so little to no gravity as you head towards the centre and more gravity as you head towards any section of the sphere, should we not have hollow spherical galaxies instead of these strange spiral galaxies where most of the matter is in the center?

    You have totally failed to explain why any galaxy looks like it is light matter only, that before the redshift thing came up, no one believed any different. we now have this DM idea because of an unproven idea about high redshifts of just about all stars in a galaxy.

    All stars are said to move at the same speed so those close to the center are in a far tighter orbit so would need considerably more gravity to hold them in place than out on the rim where they move in a very wide spiral. Yet the force of DM we are told is less as you go towards the center and more at the rim. So, again DM fails.

    Add more sugar to your drink and it tastes sweeter. Everyone accepts that as it can simply be proved to be true. There is no hidden Dark Sweetener in your drink causing this.
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  5. #105  
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    Quote Originally Posted by Cyberia View Post
    PhysBang. Redshifts measure a loss of energy by a photon since they cannot lose speed. While it is true that we can measure objects in space moving away from us by this method, we can also see how gravity redshifts photons too.

    Why is it sheer idiocy to match the redshift of a moving object to the distance it actually moves over time to see if it has no other components? Surely that is how science is done rather than just making assumptions?
    No, it is sheer idiocy to never read a scientific paper and merely assume that all astronomers and cosmologists never consider the possibility that there are other factors that influence redshift. This is something that has undergone an intense amount of scrutiny; unfortunately you are not one of the people that has done any scrutiny in this matter.
    Cosmological time dilation only works on quasars back to six billion light years away. After that it fails totally. So another explanation is needed. Strange how with all these people checking every day, including twice on Sundays, that the BB works, failed to notice this till very recently.
    Again you show your complete ignorance of this topic, right after I provided you with explicit references to measurements of time dilation. You are certainly coming across great here. I can see why you want to imagine your own physics, but can you?
    Strange how we have a spherical shape with the shell theorem but a fairly flat spiral galaxy. Surely the galaxy should be spherical too, and since so little to no gravity as you head towards the centre and more gravity as you head towards any section of the sphere, should we not have hollow spherical galaxies instead of these strange spiral galaxies where most of the matter is in the center?
    Perhaps you should do some reading about the relationship between the shell theorem and spiral galaxies?
    You have totally failed to explain why any galaxy looks like it is light matter only, that before the redshift thing came up, no one believed any different. we now have this DM idea because of an unproven idea about high redshifts of just about all stars in a galaxy.
    Cosmological redshift has nothing to do with rotation curves. This factor is cancelled out in measurements of galactic rotation because these measurements depend on the relative redshifts and blueshifts across a given galaxy.

    All stars are said to move at the same speed so those close to the center are in a far tighter orbit so would need considerably more gravity to hold them in place than out on the rim where they move in a very wide spiral. Yet the force of DM we are told is less as you go towards the center and more at the rim. So, again DM fails.
    No, we are not told that the force is less as you go towards the centre. We are told that the effect is less. This is part of the mathematics of physics that you can learn.
    Add more sugar to your drink and it tastes sweeter. Everyone accepts that as it can simply be proved to be true. There is no hidden Dark Sweetener in your drink causing this.
    You still haven't told us how this can be "proven".
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  6. #106  
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    Quote Originally Posted by PhysBang View Post
    No, it is sheer idiocy to never read a scientific paper and merely assume that all astronomers and cosmologists never consider the possibility that there are other factors that influence redshift. This is something that has undergone an intense amount of scrutiny; unfortunately you are not one of the people that has done any scrutiny in this matter.
    Can you show me a paper where a professional has considered or dismissed gravity as a part cause of stellar and galactic redshift of photons when travelling (and not in emission)?

    Again you show your complete ignorance of this topic, right after I provided you with explicit references to measurements of time dilation. You are certainly coming across great here. I can see why you want to imagine your own physics, but can you?
    I show you where the papers are wrong and you still claim they are right and babble about "my own physics". The fact that time dilation has been proved not to happen in very distant quasars now means that it cannot be trusted as a measure of distance.

    Perhaps you should do some reading about the relationship between the shell theorem and spiral galaxies?
    Another non-answer.

    Cosmological redshift has nothing to do with rotation curves. This factor is cancelled out in measurements of galactic rotation because these measurements depend on the relative redshifts and blueshifts across a given galaxy.
    What are you talking about? I showed that where DM is needed most to hold stars in the galaxy, it is weakest (according to Shell theory.) I also showed that where DM is needed least to hold stars in place, it is strongest (according to Shell theory).

    No, we are not told that the force is less as you go towards the centre. We are told that the effect is less. This is part of the mathematics of physics that you can learn.
    To quote from the wiki link you gave:

    3. Inside a solid sphere of constant density the gravitational force varies linearly with distance from the centre, becoming zero at the centre of mass.

    Force? Effect? You're playing with words.


    Add more sugar to your drink and it tastes sweeter. Everyone accepts that as it can simply be proved to be true.
    You still haven't told us how this can be "proven".
    This is just sheer desperation now. Ask a five year old kid to explain it to you.
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  7. #107  
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    Quote Originally Posted by Cyberia View Post
    Can you show me a paper where a professional has considered or dismissed gravity as a part cause of stellar and galactic redshift of photons when travelling (and not in emission)?
    Yes, see the last two papers I cited. Goldhaber et al. (The Astrophysical Journal, 558:359-368, 2001 September 1) and in Blondin et al. (The Astrophysical Journal, 682:724-736, 2008 August 1)


    I show you where the papers are wrong and you still claim they are right and babble about "my own physics". The fact that time dilation has been proved not to happen in very distant quasars now means that it cannot be trusted as a measure of distance.
    No, you tell us where you imagine papers are wrong. There is a big difference between your imagination and reality. There is no proof that there is no time dilation in distant quasars. Rather the reverse, actually.

    I can guess which paper you think "proves" that distant quasars show no time dilation and it does not say what you think it does.
    Cosmological redshift has nothing to do with rotation curves. This factor is cancelled out in measurements of galactic rotation because these measurements depend on the relative redshifts and blueshifts across a given galaxy.
    What are you talking about? I showed that where DM is needed most to hold stars in the galaxy, it is weakest (according to Shell theory.) I also showed that where DM is needed least to hold stars in place, it is strongest (according to Shell theory).
    First, the shell theorem doesn't hold for these galaxies, a very similar theory does. Second, the shell theorem doesn't say that gravity is weaker within a spherical shell, it says that its effect cancels out. Third, it more or less predicts exactly what we see, namely that the matter at the edges of spiral galaxies behaves like matter well within a distribution of matter.

    You still haven't told us how this can be "proven".
    This is just sheer desperation now. Ask a five year old kid to explain it to you.
    I was wondering what strange ideas of science you harbor. If you cannot even explain how we know that sugar makes tea sweet, something you seemed very certain of, then you have some problems.
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  8. #108  
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    Quote Originally Posted by PhysBang View Post
    If you are willing to accept the observations of the moon as "direct evidence" of how gravity works, then why not observations of galaxies and the stars within them?
    Quote Originally Posted by JoeRand View Post
    That sounds like MOND thinking, does it not? If we assume what we observe is a direct observation of all there is, or at least all that is relevant to the problem at hand, then we would simply modify our law of gravity to change with the scale of the matter configurations observed, without invoking unknown and undetectable forms of matter and energy to explain their changing patterns of motion. It is because we look for laws that are universally valid that such an idea bothers us, and we instead go around the directly observable and imagine there is dark matter and energy filling in the necessary gaps.
    Quote Originally Posted by PhysBang View Post
    Why must you misinterpret what I write?
    Sorry. I did not intend to. Neither did I question the validity of observations of large distant objects. The problem is not the observations themselves, but how to explain the discrepancy in the observed motion. So, I do not know why you are saying that I am not willing to accept observations of large distant objects. The whole point here is that dark matter is not directly observable, and has yet to be definitely encountered in a lab. The concept of dark matter is not a direct observation of how gravity works.

    Quote Originally Posted by JoeRand View Post
    Considering only small proximate bodies, we have never before needed to invoke invisible matter and energy as contributing factors to describe their motion.
    Quote Originally Posted by PhysBang View Post
    You should acquaint yourself with the history of physics.
    What do you mean? I am not familiar with another instance where assuming dark material exists is necessary.
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  9. #109  
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    [QUOTE=PhysBang;288847]Yes, see the last two papers I cited. Goldhaber et al. (The Astrophysical Journal, 558:359-368, 2001 September 1) and in Blondin et al. (The Astrophysical Journal, 682:724-736, 2008 August 1)

    They assume that all Type 1a Supernovae are the same when they are not, and they only used a tiny sample when they should have used a large one, and being back in ye olde days, they did not make the necessary corrections:

    Variability in Type 1A Supernovae Has Implications for Studying Dark Energy




    Type 1A supernovae can produce a number of non-standard results for various reasons including simply spinning faster than expected.


    No, you tell us where you imagine papers are wrong. There is a big difference between your imagination and reality. There is no proof that there is no time dilation in distant quasars. Rather the reverse, actually/

    I can guess which paper you think "proves" that distant quasars show no time dilation and it does not say what you think it does.
    .
    I ask you for papers that back up what you say and having no answer, you then ask me for papers, Duh!

    As to time dilation, always ready to prove you wrong:

    Discovery that quasars don't show time dilation mystifies astronomers


    First, the shell theorem doesn't hold for these galaxies, a very similar theory does. Second, the shell theorem doesn't say that gravity is weaker within a spherical shell, it says that its effect cancels out. Third, it more or less predicts exactly what we see, namely that the matter at the edges of spiral galaxies behaves like matter well within a distribution of matter.
    It's shameful to see you trying to contradict what you said earlier and the link you provided.

    I was wondering what strange ideas of science you harbor. If you cannot even explain how we know that sugar makes tea sweet, something you seemed very certain of, then you have some problems.
    As Amos McCoy would say: "It's pitiful, I tell ya. Just pitiful."

    Or Mohammad Ali:

    "I pity the fool".
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  10. #110  
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    Quote Originally Posted by Cyberia View Post
    They assume that all Type 1a Supernovae are the same
    No, they don't. Anyone who reads these papers can see that. Every time you write something, it shows how addled you are. You are free to lie all you want, but anyone who takes the time to read will see easily that you are a liar.
    when they are not, and they only used a tiny sample when they should have used a large one, and being back in ye olde days, they did not make the necessary corrections:

    Variability in Type 1A Supernovae Has Implications for Studying Dark Energy




    Type 1A supernovae can produce a number of non-standard results for various reasons including simply spinning faster than expected.
    You don't even read the things you link to.


    I ask you for papers that back up what you say and having no answer, you then ask me for papers, Duh!

    As to time dilation, always ready to prove you wrong:

    Discovery that quasars don't show time dilation mystifies astronomers
    Yep, I figured that you would reference, via a poor pop science article, the Hawkins piece. Hawkins' paper does not show that quasars don't have time dilation, the paper shows that Hawkins' method for finding time dilation doesn't work. He tried to do a complicated statistical method to find time dilation indirectly. So far, we have direct measurements of supernova time dilation. E.g., 1991ApJ...382L...1D Page L1


    First, the shell theorem doesn't hold for these galaxies, a very similar theory does. Second, the shell theorem doesn't say that gravity is weaker within a spherical shell, it says that its effect cancels out. Third, it more or less predicts exactly what we see, namely that the matter at the edges of spiral galaxies behaves like matter well within a distribution of matter.
    It's shameful to see you trying to contradict what you said earlier and the link you provided.[/quote]
    What I wrote before was that the shell theorem is an example of where gravity doesn't merely attract to where the most mass is. Sadly, I provided a link to wikipedia in my haste; linking to wikipedia is almost always foolish.

    Again, I was wondering what strange ideas of science you harbor. If you cannot even explain how we know that sugar makes tea sweet, something you seemed very certain of, then you have some problems.
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  11. #111  
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    PhysBang. Is this your evidence for what you claim:

    No, they don't. Anyone who reads these papers can see that. Every time you write something, it shows how addled you are. You are free to lie all you want, but anyone who takes the time to read will see easily that you are a liar.
    Let's see, should I trust :

    Astronomer Mike Hawkins from the Royal Observatory in Edinburgh came to this conclusion after looking at nearly 900 quasars over periods of up to 28 years.
    Or should I trust Hawking who has done no such research in this field and will be relying on his name to carry him through?


    If you have a version of Shell theorem which is different from the wikipedia and supports what you claim, I will look at it.


    You asked how we could prove that sugar makes things sweet?

    I am sure that everyone here could tell you, especially if they drink hot drinks.

    You have reached Australia. Time to stop digging that hole.
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  12. #112  
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    Quote Originally Posted by Cyberia View Post
    Let's see, should I trust :

    Astronomer Mike Hawkins from the Royal Observatory in Edinburgh came to this conclusion after looking at nearly 900 quasars over periods of up to 28 years.
    Or should I trust Hawking who has done no such research in this field and will be relying on his name to carry him through?
    Since you cannot even get his name right, then it doesn't really matter who you trust.

    If you were actually half-way competent, you might want to look at the citations to the Hawkins paper. It is too much to believe that you could actually read the paper yourself. If you could, you would see that he doesn't actually directly measure the time dilation of any quasars.
    If you have a version of Shell theorem which is different from the wikipedia and supports what you claim, I will look at it.
    Look at any textbook in gravitational physics.
    You asked how we could prove that sugar makes things sweet?

    I am sure that everyone here could tell you, especially if they drink hot drinks.
    The point is that you can't answer the question. I suspect that you realize that trying to answer the question would make many of your previous answers look insanely foolish.
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