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Thread: Lightspeed isn't constant?

  1. #1 Lightspeed isn't constant? 
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    Is light speed constant and is the universe expanding at an increasingly faster rate?
    I read somewhere that the universe is expanding at an increasingly faster rate. The further out, the faster itís expanding. I donít believe in dark energy (making the universe expand faster). I also read somewhere that gravity slows down time. Is it possible that the lack of gravity at the edge of the universe is making time run faster (including light)? The light that we see is being buffered by the increasing gravity as it approaches us creating the illusion that the universe is expanding at an increasingly faster rate. Same with the light we see from the centre of the universe creating the illusion that itís expanding at a slower rate.


     

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  3. #2 Re: Lightspeed isn't constant? 
    Universal Mind John Galt's Avatar
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    Quote Originally Posted by Spacedman
    Is light speed constant
    Definitely.
    Quote Originally Posted by Spacedman
    is the universe expanding at an increasingly faster rate?
    Apparently.
    Quote Originally Posted by Spacedman
    I donít believe in dark energy (making the universe expand faster).
    You are entitled to believe anything you wish. If that belief is not based upon a sound, scientific foundation you cannot expect anyone to give much regard to your belief.
    Quote Originally Posted by Spacedman
    I also read somewhere that gravity slows down time. Is it possible that the lack of gravity at the edge of the universe is making time run faster (including light)? .
    No.


     

  4. #3 Re: Lightspeed isn't constant? 
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    Quote Originally Posted by Spacedman
    I also read somewhere that gravity slows down time. Is it possible that the lack of gravity at the edge of the universe is making time run faster (including light)?
    Faster relative to what? Also, it's gravitational potential which causes the dilation effect, not so much gravity itself. Further, gravity is never absent, just greatly diminished in strength/magnitude the farther away from a massive object one gets.


    Quote Originally Posted by Spacedman
    The light that we see is being buffered by the increasing gravity as it approaches us creating the illusion that the universe is expanding at an increasingly faster rate. Same with the light we see from the centre of the universe creating the illusion that itís expanding at a slower rate.
    Why use the term "illusion?" Do you disregard the validity of this area of study?
     

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    The speed of light is constant in a vacuum (whatever a vacuum is, empty space...but space is never empty) its pretty steady tho in whatever medium it travels in.

    Like Ophiolite says, you cant believe something isnt true just because you want to. Scientists deal in absolutes, you have to proove that Dark Energy is not a good theoretical model...by producing something more compelling that stands up to mathematical analysis and observation.
     

  6. #5  
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    I think its an interesting question in that you may be right about effects of the redshift from stars that may be interfered with, maybe not by gravity but by other sources unknown to us now. We may well not have a universe expanding as highly as we think however we can only use the methods & techniques we understand and know.

    Whereas Dark Energy I believe does exist, we can not say for sure what it is or if it is by any chance energy at all but there is something causing expansion in the universe which we cannot see or understand yet, therefore dark energy may in fact be another force that we find in our universe, or it may be matter in higher dimensions, other universes situation on top of ours....many different things. Dark energy is just teh term to expain the expansion until we understand it more.
     

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    Light travels at a set speed in a set medium.

    Lately I have considered that gravity may be a bit faster than light which would allow that matter too could break light speed, even if only by a tiny fraction of one percent.
     

  8. #7  
    Universal Mind John Galt's Avatar
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    Quote Originally Posted by Cyberia
    Lately I have considered that gravity may be a bit faster than light which would allow that matter too could break light speed, even if only by a tiny fraction of one percent.
    Lately I've considered that if all the dumb-ass, unsubstantiated, delusional, self indulgent, "I've got a theory, but no education", off the cuff, fly in the face of common sense, deliberately unconventional speculations that are propounded on internet forums in a year were laid end to end they' d bypass Buzz LightYear.
     

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    Ophilolite. You know absolutely nothing about my idea (it is not a theory as you would know if you knew what the scientific definition of the word was) yet you dismiss it because you see your place on this forum as playground yob.
     

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    So, if it expands in faster rate, will it continues infinitely ? And what do you think about the oscillating universe ?
     

  11. #10  
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    Quote Originally Posted by Cyberia
    Ophilolite. You know absolutely nothing about my idea (it is not a theory as you would know if you knew what the scientific definition of the word was) yet you dismiss it because you see your place on this forum as playground yob.
    Cyberia:
    1. I love you very much too.

    2. You will observe that where I say 'theory' I have placed it in quotation marks, the quotation implicitly assigned to yourself, or others who deliver similar 'theories'.

    My deliberate selection of those quotation marks is evidence that I fully understand what a theory is in the scientific sense. Were you to spend time sorting through my posts here and on other internet forums (don't waste your time) you would find ample evidence that I not only have a very clear idea of what constitutes a scientific theory, but I have some minor skill in communicating this idea to others.

    Consequently, as in so many things, you have misinterpreted your observations and jumped to a concussion. Short version: you are mistaken.

    3. I know that your speculation involves the possiblity that gravity is a bit faster than light. So I do know something of your idea. I do not - as you claim - no absolutely nothing. Once again, in so few words, you are proven wrong. It's a great skill.

    4. Do not presume to know what I think. It merely affords you another opportunity to be wrong.

    5. One of the 'roles' I choose to take on this forum is to prick the self righteous pomposity of those who present their own ideas in the same manner as they present accepted science. This is of know concern for those versed in a particular topic, but it is damaging to those who are neophytes. They can be easily mislead into thinking that off-the-wall speculations are hard science.

    That behaviour is irresponsible and antithetical to the role of an educator. You practice this from time to time. So, if you choose to act like an irresponsible prick you must expect to be called out on it from time to time.

    6. I dismiss your idea because you offer zero substantiating evidence and appear to have withdrawn it from some bodily cavity where the sun don't shine.
     

  12. #11  
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    At this point, I wield my right of a moderator (in the full sense of the literal meaning) to call everyone to order here. I understand the frustration of some people with others, but may I ask for some relaxation?

    Cyberia: Will you please from now on clearly indicate, whenever you diverge from the realm of accepted and confirmed science? I totally support Ophiolite's concern that it is almost impossible for newbies to distinguish between consolidated science, working hypotheses and pure speculation. Please support your claims that lie off of the main path either with qualified quotes or clearly indicate that it is your own speculation.

    Ophiolite: As much as I sympathise with your feelings, please try to stay on topic without actually criticising the personality of the forum members. However, I do not object, whenever you emphasise the logical and scientific shortcomings in the posts. As long as it is clear, how much of the post is actually based on solid science, I don't want to restrict the right free speech.

    Let me be clear, that my impression is that at least the majority of the other moderators and the forum owners is that Ophiolite's criticism is often tough, but almost never unjustified.

    Best regards,
    Dishmaster (Moderator).
     

  13. #12 Re: Lightspeed isn't constant? 
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    Quote Originally Posted by Spacedman
    Is light speed constant and is the universe expanding at an increasingly faster rate?
    It depends on what you exactly mean. I have the impression that your phrasing is a bit inaccurate which leads to false conclusions.
    Quote Originally Posted by Spacedman
    I read somewhere that the universe is expanding at an increasingly faster rate. The further out, the faster itís expanding.
    These are two totally different things. There are some indications that the expansion of the universe might actually be speeding up. This means that the distance between two arbitrary points increases at a faster rate than before. This has nothing to do with the fact that more distant objects appear to have higher expansion velocities than closer objects. The expansion is measured as a velocity per distance unit. Take the following example: There are three points in space, a-b-c. The distance between a and b is the same as the distance between b and c. Due to cosmic expansion, the velocities measured between a and b as well as b and c are the same. However, relative to a, the velocity of c is twice as high. So, even with a constant expansion, more distant objects recede at higher speeds.
    Quote Originally Posted by Spacedman
    I donít believe in dark energy (making the universe expand faster).
    This is scientifically irrelevant. I don't like it either, but it fits the observations we make. So, in order to neglect Dark Energy (nobody knows actually, what it is; it is just a name for something we don't understand), you would have to come up with a different idea how to explain the facts. Something is driving the expansion - be it accelerated or not.
    Quote Originally Posted by Spacedman
    I also read somewhere that gravity slows down time. Is it possible that the lack of gravity at the edge of the universe is making time run faster (including light)?
    No, that does not work. Time only "slows down" relative to to another reference frame. There is also no edge of the universe. In fact, based on simple physics, such a configuration you are proposing would lead to a gravitational collapse, because the over-abundance in the "middle" would exert an attractive force to the outside, thus breaking the expansion.
    Quote Originally Posted by Spacedman
    The light that we see is being buffered by the increasing gravity as it approaches us creating the illusion that the universe is expanding at an increasingly faster rate. Same with the light we see from the centre of the universe creating the illusion that itís expanding at a slower rate.
    I don't understand this. Matter is evenly distributed on very large scales. There is no centre of the universe, where the mass density appears to be increasing. Not a single observation we make supports your idea.
     

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    IMHO there seems little point to telling everyone a theory in the hope that it is immediately accepted without publication, peer review and scrutiny via the appropriate scientific discourse.

    Needless to say people shouldn't go in all guns blazing as if its 100% false, just disect the fallacy of something bit by bit, and make sure the speculator undestands exactly why you disagree with a theory, instead of blazing someone down as ignorant just because they haven't got a PhD in astrophysics.
     

  15. #14  
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    Quote Originally Posted by Dishmaster
    I understand the frustration of some people with others, but may I ask for some relaxation?
    I did say I loved him. :wink:

    As much as I sympathise with your feelings, please try to stay on topic without actually criticising the personality of the forum members
    You are absolutely right. It's just at my age I have few other pleasures left. I'll try to behave myself before sliding (further) into graceless senility.

    Michael, for all I know Cyberia has a Ph.D. in astrophysics. "Extraordinary claims require extraodinary evidence." He has provided none. Until he does I shall view his speculation with considerable scepticism. I think that's as it should be.
     

  16. #15 Re: Lightspeed isn't constant? 
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    Quote Originally Posted by Spacedman
    I donít believe in dark energy (making the universe expand faster).
    Science works independent of whether or not you choose to believe.

    Further, the speed of light is not a constant. It has different speeds in different media.
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  17. #16 Re: Lightspeed isn't constant? 
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    Quote Originally Posted by dave922
    Further, the speed of light is not a constant. It has different speeds in different media.
    No, actually. The speed of light is most certainly constant, and is so in all reference frames and media. The only thing which will change is its "apparent" speed, essentially a perceptual effect which results from the fact that in different media the photon travels via a longer path.
     

  18. #17 Re: Lightspeed isn't constant? 
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    Quote Originally Posted by inow
    Quote Originally Posted by dave922
    Further, the speed of light is not a constant. It has different speeds in different media.
    No, actually. The speed of light is most certainly constant, and is so in all reference frames and media. The only thing which will change is its "apparent" speed, essentially a perceptual effect which results from the fact that in different media the photon travels via a longer path.
    Sorry, wrong. The statement that it varies with media type is correct. It only travels about 200,000 km/sec in glass.
     

  19. #18 Re: Lightspeed isn't constant? 
    Moderator Moderator Janus's Avatar
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    Quote Originally Posted by Wild Cobra
    Quote Originally Posted by inow
    Quote Originally Posted by dave922
    Further, the speed of light is not a constant. It has different speeds in different media.
    No, actually. The speed of light is most certainly constant, and is so in all reference frames and media. The only thing which will change is its "apparent" speed, essentially a perceptual effect which results from the fact that in different media the photon travels via a longer path.
    Sorry, wrong. The statement that it varies with media type is correct. It only travels about 200,000 km/sec in glass.
    Nope. The apparent speed of light in glass is 200,000 km/sec. But it travels through glass at 300,000 km/sec.

    How is this possible?. By the fact that it is not traveling the whole time it is passing through the glass. As a photon travels through the glass, it encounters molecules. When it does, these molecules absorb the photon and its energy. After a slight delay, the molecule gives up the energy and emits a photon, which travels on its way until it encounters another molecule. The photon travels at c between molecules and it is the delay between absorption and emission that causes the apparent loss in speed.

    Its like having a car driving through the city at a constant 30 mph while driving, but having to stop at stoplights along the way. Between lights it travels at 30 mph, but if you time how long it takes for it to cross the city, you get an average speed of less than 30 mph.

    BTW, this same absorption/emission process that is being taken advantage of in those experiments where they say that they have slowed light to some very small value. What they have done is create a substance in which the delay between absorption and emission for each atom is extremely long.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  20. #19 Re: Lightspeed isn't constant? 
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    Quote Originally Posted by Wild Cobra
    Sorry, wrong.
    Yes. Yes, you were. You're nothing if not consistent, WC.


    Thanks also to Janus for the clarity and accessibility of your explanation.
     

  21. #20  
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    Nice correction of a correction of a correction.
    'Aint no thing like a chicken wing'
     

  22. #21 Re: Lightspeed isn't constant? 
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    Quote Originally Posted by Janus
    Its like having a car driving through the city at a constant 30 mph while driving, but having to stop at stoplights along the way. Between lights it travels at 30 mph, but if you time how long it takes for it to cross the city, you get an average speed of less than 30 mph.

    BTW, this same absorption/emission process that is being taken advantage of in those experiments where they say that they have slowed light to some very small value. What they have done is create a substance in which the delay between absorption and emission for each atom is extremely long.

    Janus, I really like that example you gave. That describes photon the particle perfectly. But sometimes I like to think of photon the wave and waves actually do travel at different speeds through different mediums. Can anybody reconcile this for me.
     

  23. #22  
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    You're thinking of a 'classical' wave in which the medium is 'waving'. Light is NOT a waving of a medium. The aether was discarded a long time ago.
     

  24. #23  
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    Migl, when I made my comment about photon the wave I was thinking about waveĖparticle duality and whether there would be a simple explanation from the wave point of view. After investigating a bit I don't think so. Thanks for your response.
     

  25. #24  
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    Quote Originally Posted by Michael_Roberts
    IMHO there seems little point to telling everyone a theory in the hope that it is immediately accepted without publication, peer review and scrutiny via the appropriate scientific discourse.

    Needless to say people shouldn't go in all guns blazing as if its 100% false, just disect the fallacy of something bit by bit, and make sure the speculator undestands exactly why you disagree with a theory, instead of blazing someone down as ignorant just because they haven't got a PhD in astrophysics.
    True, but on this forum it is the responsibility of us posters to clearly indicate when we're saying something is our own theory, so lurkers don't mistake our own theories for established science. That said: Cyberia did so.

    Quote Originally Posted by Cyberia
    Lately I have considered that gravity may be a bit faster than light which would allow that matter too could break light speed, even if only by a tiny fraction of one percent.
    "Lately I have considered" is a good setup to make it clear one is posting their own hypothesis, rather than an established theory.


    Quote Originally Posted by Ophiolite
    Michael, for all I know Cyberia has a Ph.D. in astrophysics. "Extraordinary claims require extraodinary evidence." He has provided none. Until he does I shall view his speculation with considerable scepticism. I think that's as it should be.
    It turns out in this specific case, that there actually is some evidence for this theory (at least the first part of it), though Cyberia did not post it.

    http://www.thescienceforum.com/Is-it...ght-20256t.php

    http://www.universetoday.com/11889/h...peed-of-light/

    If high energy gamma rays travel slightly slower than low energy radio waves, then we can infer from this that gravity waves also can be expected to travel at a slightly different speed than either the gamma rays or the radio waves. So I don't know about the second part, but the first part of what she said is likely to be true.
     

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    Quoted: Its like having a car driving through the city at a constant 30 mph while driving, but having to stop at stoplights along the way. Between lights it travels at 30 mph, but if you time how long it takes for it to cross the city, you get an average speed of less than 30 mph".

    The more plausible explanation is that light is affected by denser matter, such as glass, that it actually slows down passing through light. Light is not alive like human being driving a car that can slow down, halt on every station, and speed off constantly?

    jsaldea12
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  27. #26  
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    Quote Originally Posted by jsaldea12
    The more plausible explanation is that light is affected by denser matter, such as glass, that it actually slows down passing through light.
    Whether or not it is more plausible, it is not correct. The apparent reduction of lightspeed in non-vaccum is due to the abosrbtion and re-emittance of light. The time delay for this process creates the impression of a reduced speed. The analogy of traffic lights is not a bad one.
     

  28. #27  
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    Quote Originally Posted by Ophiolite
    Quote Originally Posted by jsaldea12
    The more plausible explanation is that light is affected by denser matter, such as glass, that it actually slows down passing through light.
    Whether or not it is more plausible, it is not correct. The apparent reduction of lightspeed in non-vaccum is due to the abosrbtion and re-emittance of light. The time delay for this process creates the impression of a reduced speed. The analogy of traffic lights is not a bad one.
    An even more suitable analogy would be a car recycling station. Each time the car stops, it is crushed, recycled and a new, yet identical, car is produced.
     

  29. #28  
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    Quote Originally Posted by Dishmaster
    An even more suitable analogy would be a car recycling station. Each time the car stops, it is crushed, recycled and a new, yet identical, car is produced.
    Sometimes it comes with a different colour paint job.
     

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    Light when passing through a thick glass is dimmed after passing through. True, light interacts with glass , the dense glass absorbs light and further reduces its speed. That is why light is dimmed. But the best illustration why light is affected by dense matter is because all matter has atoms which has electro-magnetic property, thus strong strong electro-magnetic gravitational force of black hole prevents light from escaping.

    Jsaldea12
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  31. #30  
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    Quote Originally Posted by jsaldea12
    Light when passing through a thick glass is dimmed after passing through. True, light interacts with glass , the dense glass absorbs light and further reduces its speed. That is why light is dimmed. But the best illustration why light is affected by dense matter is because all matter has atoms which has electro-magnetic property, thus strong strong electro-magnetic gravitational force of black hole prevents light from escaping.

    Jsaldea12
    11.18.10
    Actually that is not correct. Light is dimmed only because some of it gets reflected or absorbed by the glass. Not all of it gets through.

    It's final speed is totally unaffected. It does slow down when it enters the glass, but it speeds right back up again to its normal speed the moment it leaves the glass.
     

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    Quoted, ď t's final speed is totally unaffected. It does slow down when it enters the glass, but it speeds right back up again to its normal speed the moment it leaves the glassĒ.

    Light travels best at vacuum outer space. Even in air where there is too much space. But light under denser water travels slower, the same with glass. The same with electricity travelling in dense electrical lines. Why is it slowed or delayed or weaker as light or electricity passes through because it clashes and passes through with such dense matters. Light is like waves passing through breakwater that is slowed down, lessened and weakened.

    jsaldea12

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  33. #32  
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    The absorption/emission description was exactly correct as far as light-travel through a medium. Why is it still being discussed otherwise or in variations?

    I contend that the more interesting topic would be that which pertains to gravitation.
     

  34. #33  
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    Quote Originally Posted by TheDr.Spo
    I contend that the more interesting topic would be that which pertains to gravitation.
    Gravitation does not affect the speed of light. It does affect the frequency.
     

  35. #34  
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    Quote Originally Posted by DrRocket
    Quote Originally Posted by TheDr.Spo
    I contend that the more interesting topic would be that which pertains to gravitation.
    Gravitation does not affect the speed of light. It does affect the frequency.
    What about the special condition of light inside the event horizon of a black hole? If you are saying that gravity under these conditions has not changed the speed of light. What is your explanation of why light is unable to escape from the black hole.
     

  36. #35  
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    Quote Originally Posted by Lance Wenban
    Quote Originally Posted by DrRocket
    Quote Originally Posted by TheDr.Spo
    I contend that the more interesting topic would be that which pertains to gravitation.
    Gravitation does not affect the speed of light. It does affect the frequency.
    What about the special condition of light inside the event horizon of a black hole? If you are saying that gravity under these conditions has not changed the speed of light. What is your explanation of why light is unable to escape from the black hole.
    Spacetime is sufficiently curved that no null geodesics inside the event horizon cross the horizon. The speed of light is the same everywhere.

    Black holes are described by general relativity. There is no explanation in terms of Newtonian gravity.
     

  37. #36  
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    If the light pulse is long enough, and the trajectory relative to an external observer (though you can't observe it) is circular, what is the consequence, if any, of the "head" of the pulse being superimposed on the "tail" of the pulse?

    Would you treat this as two seperate waves following the same trajectory?

    If gravity changes the frequency of the photons, does this superposition increase the frequency?

    If a black hole effectively "charges up" with light in this way with the light from surrounding stars, like many spindles of thread being transferred into an increasingly compact bundle of thread (to use a metaphor), how is this energy being stored?

    Wouldn't it be extremely bright and hot if you could take measurements from beyond the event horizon?

    .o:0|O|0:o.
     

  38. #37  
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    Quote Originally Posted by DrRocket
    Quote Originally Posted by Lance Wenban
    Quote Originally Posted by DrRocket
    Quote Originally Posted by TheDr.Spo
    I contend that the more interesting topic would be that which pertains to gravitation.
    Gravitation does not affect the speed of light. It does affect the frequency.
    What about the special condition of light inside the event horizon of a black hole? If you are saying that gravity under these conditions has not changed the speed of light. What is your explanation of why light is unable to escape from the black hole.
    Spacetime is sufficiently curved that no null geodesics inside the event horizon cross the horizon. The speed of light is the same everywhere.

    Black holes are described by general relativity. There is no explanation in terms of Newtonian gravity.
    I think you are saying that light is in orbit around the black hole when inside the event horizon. That's an interesting concept that would be hard to prove one way or the other, but I like it.
     

  39. #38  
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    Another thought:

    If the frequency of light is affected by gravity, is gravity affected by the frequency of light? If so, and if the above suggested superposition causes the waves to increase their frequency, would it be theoretically possible to curve space by firing photons, laser beams, through an ideal fiberoptic hoop?

    .o:0|O|0:o.
     

  40. #39  
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    Another thought:

    If there is any sense to the above argument, would it not then be possible to find massive objects in space that collectively cause light to travel over itself as suggested above (not necessarily over a perfectly circular trajectory). That is, light travels nearby a massive star, some of it is deviated; the deviated light is then deviated again by a second mass, and so forth until the light travels back over its self. Perhaps there is somewhere out there an arrangement of this sort that causes space-time to warp at the foci of this hoop, if only marginally (?)

    .o:0|O|0:o.
     

  41. #40  
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    Sorry I don't know anything about how gravity affects the frequency of light so I'm not going to comment on that subject.
     

  42. #41  
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    A further thought:

    Could these hypothetical light hoops cause space-time to warp to the extent that other light, passing in the vicinity of these foci, is deviated in such a way that it appears to be passing a mass, though no mass exists at that point?

    .o:0|O|0:o.
     

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    Quote Originally Posted by Lance Wenban
    I think you are saying that light is in orbit around the black hole when inside the event horizon. That's an interesting concept that would be hard to prove one way or the other, but I like it.
    I said no such thing, and "in orbit around the black hole when inside the event horizon" is a meaningless phrase. A black hole is not something inside the event horizon. Basically, what is called a "black hole" is the event horizon and everything inside.
     

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    Quote Originally Posted by DrRocket
    Quote Originally Posted by Lance Wenban
    I think you are saying that light is in orbit around the black hole when inside the event horizon. That's an interesting concept that would be hard to prove one way or the other, but I like it.
    I said no such thing, and "in orbit around the black hole when inside the event horizon" is a meaningless phrase. A black hole is not something inside the event horizon. Basically, what is called a "black hole" is the event horizon and everything inside.
    That's a true statement, but there is speculation about the composition of a black hole just the other side of the event horizon and some consensus on various possibilities. The picture that is usually presented is the compressed matter core of a black hole is a great deal smaller than the event horizon diameter. Sometimes referred to as a singularity. I happen to think the term singularity is a complete misnomer and shouldn't be used, however I don't have a problem believing there could be a great deal of empty space between the event horizon and some form of solid surface inside the black hole. If that does happen to be the case, then the question of what happens to a photon from the time it crosses the event horizon until it's absorbed by some form of matter becomes relevant. I know that question may never get answered, but then it's got lots of company.
     

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    Quote Originally Posted by Lance Wenban
    Quote Originally Posted by DrRocket
    Quote Originally Posted by Lance Wenban
    I think you are saying that light is in orbit around the black hole when inside the event horizon. That's an interesting concept that would be hard to prove one way or the other, but I like it.
    I said no such thing, and "in orbit around the black hole when inside the event horizon" is a meaningless phrase. A black hole is not something inside the event horizon. Basically, what is called a "black hole" is the event horizon and everything inside.
    That's a true statement, but there is speculation about the composition of a black hole just the other side of the event horizon and some consensus on various possibilities. The picture that is usually presented is the compressed matter core of a black hole is a great deal smaller than the event horizon diameter. Sometimes referred to as a singularity. I happen to think the term singularity is a complete misnomer and shouldn't be used, however I don't have a problem believing there could be a great deal of empty space between the event horizon and some form of solid surface inside the black hole. If that does happen to be the case, then the question of what happens to a photon from the time it crosses the event horizon until it's absorbed by some form of matter becomes relevant. I know that question may never get answered, but then it's got lots of company.
    What you think is irrelevent, Roger Penrosr proved that, based on general relativity, the interior of a black hole is singular. There is no misnomer. Whether or not a proper theory of quantum gravity would show something else is not known, since we have no such theory yet.

    Speculation is just that - speculation, and is just as irrelevevt as what you think.

    What general relativity predicts is that one would notice essentially no change on crossing the event horizon. The exotic effects occur much deeper into the black hole.

    I have no idea what you have in mind by :" some form of solid surface inside the black hole", and neither do you.

    Your post is just speculative BS, and has nothing to do with science. Put a sock in it.[/i]
     

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    Quote Originally Posted by Ophiolite
    Quote Originally Posted by Cyberia
    Ophilolite. You know absolutely nothing about my idea (it is not a theory as you would know if you knew what the scientific definition of the word was) yet you dismiss it because you see your place on this forum as playground yob.
    Cyberia:
    1. I love you very much too.
    Is there anyone other than text book parrots that you love?

    2. You will observe that where I say 'theory' I have placed it in quotation marks, the quotation implicitly assigned to yourself, or others who deliver similar 'theories'.
    No, you placed a sentence in quotation marks, there for all to see.

    My deliberate selection of those quotation marks is evidence that I fully understand what a theory is in the scientific sense. Were you to spend time sorting through my posts here and on other internet forums (don't waste your time) you would find ample evidence that I not only have a very clear idea of what constitutes a scientific theory, but I have some minor skill in communicating this idea to others.
    This seems to be done by hurling insults at them at their lack of education as in:

    Lately I've considered that if all the dumb-ass, unsubstantiated, delusional, self indulgent, "I've got a theory, but no education", off the cuff, fly in the face of common sense, deliberately unconventional speculations that are propounded on internet forums in a year were laid end to end they' d bypass Buzz LightYear.
    So I repeat that you are nothing more than a playground yob.

    Consequently, as in so many things, you have misinterpreted your observations and jumped to a concussion. Short version: you are mistaken.
    "I've got a theory, but no education". You being mistaken about where the quotation marks are.

    3. I know that your speculation involves the possiblity that gravity is a bit faster than light. So I do know something of your idea. I do not - as you claim - no absolutely nothing. Once again, in so few words, you are proven wrong. It's a great skill.
    It has been suggested that photons could have mass but it would be below 10^-35 kg. It would explain how light can be bent / refracted by gravity rather than the nonsense about bending space.

    4. Do not presume to know what I think. It merely affords you another opportunity to be wrong.
    I know what you think. I only have to look at a text book or the wiki for any answer you might give to a question (ignoring insults added).

    5. One of the 'roles' I choose to take on this forum is to prick the self righteous pomposity of those who present their own ideas in the same manner as they present accepted science. This is of know concern for those versed in a particular topic, but it is damaging to those who are neophytes. They can be easily mislead into thinking that off-the-wall speculations are hard science.
    That behaviour is irresponsible and antithetical to the role of an educator. You practice this from time to time. So, if you choose to act like an irresponsible prick you must expect to be called out on it from time to time.
    Interpretation: Playground yob who quotes from textbooks who with creationist zeal believes every word of a text book is infallibly true from the first to the last. Every since forum has them.

    6. I dismiss your idea because you offer zero substantiating evidence and appear to have withdrawn it from some bodily cavity where the sun don't shine.
    A ten year old could have made such a comment but would probably have sufficient manners not to.
     

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    Quote Originally Posted by DrRocket

    What you think is irrelevent, Roger Penrosr proved that, based on general relativity, the interior of a black hole is singular. There is no misnomer. Whether or not a proper theory of quantum gravity would show something else is not known, since we have no such theory yet.
    A one dimensional singularity cannot spin. A black hole does. A singularity cannot grow in size. A black hole horizon does, to larger than our solar system size.

    A neutron star is made of neutrons and has sufficient gravitational force that escape velocity can be 2/3 c. At that density, neutrons still exist! Show me any evidence that fundamental particles can be crushed out of existence into the singularity which Hawking discarded years ago.
     

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    Quote Originally Posted by Lance Wenban
    Sorry I don't know anything about how gravity affects the frequency of light so I'm not going to comment on that subject.
    Gravity cannot slow photons down so they lose energy by redshifting with ever longer wave lengths.
     

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by DrRocket

    What you think is irrelevent, Roger Penrosr proved that, based on general relativity, the interior of a black hole is singular. There is no misnomer. Whether or not a proper theory of quantum gravity would show something else is not known, since we have no such theory yet.
    A one dimensional singularity cannot spin. A black hole does. A singularity cannot grow in size. A black hole horizon does, to larger than our solar system size.
    What is your point ?

    The singularity in a black hole is not even part of spacetime, so talking about spin of the singularity is meaningless.

    Spin is a characteristic of a black hole. In fact the "no hair" theorem characterizes (stationary) black holes in terms of just 3 things-- mass, spin (angular momentum), and electric charge. The Kerr and Kerr-Newman solutions of the equations of general relativity describe spinning black holes.
     

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    DrRocket. You seem to be confusing magic and science. The laws of science apply to everything, even black hole interiors. They are just more extreme. We have no evidence that fundamental particles can be destroyed. That leaves a spinning ball of particles in the centre of a black hole.

    If the centre is not part of spacetime, explain where the gravity comes from?

    A satellite orbiting the Earth shows that it is affected by the spin of the Earth, by what is below it. How does an event horizon spin unless it has the same basic principle?

    I am glad they finally dumped non-spinning black holes. Every massive thing in space spins, so they were ridiculous, based on the idea that a singularity cannot spin.
     

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    No, you seeem to have your science confused.
    When a massive star undergoes gravitational colapse to become a black hole the only information available to us afterwards is solely represented by the event horizon. Information limited to mass, charge, angular momentum and, arguably, entropy. We have no knowledge of what is inside the event horizon, be it a singularity or a sizeable something or even quantum foam. We don't even know that our physical laws apply inside the event horizon, it is, in effect a barrier between the interior and 'our' space time.
    That being said, when a star of 10 or more solar masses (I believe) collapses, there is no mechanisms that we know of ( like the Pauli excluson principle for white dwarfs up to 4.5 solar masses and neutron degeneracy for pulsars ) which will stop the collapse until it ultimately becomes a point. I repeat, THAT WE KNOW OF.
     

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    I would also like to add that the event horizon IS space/time curved in on itself, and according to GR the gravity comes from the curvature imparted to space/time by gravitational collapse of the massive star, not the possible singularity inside.
    Blach holes were first postulated as solutions to GR, the simplest case being non-rotating, by Swartzchild during WW1. The rotating solution, being much more difficult, is attributed to Kerr, I believe, and came much later. The fact that we may never actually come across a non rotating black hole is inconsequential.
     

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    Quote Originally Posted by Cyberia
    DrRocket. You seem to be confusing magic and science. The laws of science apply to everything, even black hole interiors. They are just more extreme. We have no evidence that fundamental particles can be destroyed. That leaves a spinning ball of particles in the centre of a black hole.

    If the centre is not part of spacetime, explain where the gravity comes from?

    A satellite orbiting the Earth shows that it is affected by the spin of the Earth, by what is below it. How does an event horizon spin unless it has the same basic principle?

    I am glad they finally dumped non-spinning black holes. Every massive thing in space spins, so they were ridiculous, based on the idea that a singularity cannot spin.
    I am not confusing anything. I am most certainly not confusing you with an informed intelligent individual. Once again you have produced a tour de force of ignorance.

    Here is the truth, if you can put together the wherewithal to understand the truth.

    While the underlying laws of physics may apply everywhere, the known laws of physics most certainly do not.

    What we understand of black holes comes from general relativity. It explains the non-quantum phenomena associated with black holes quite well. In particular it explains the large-scale structure of black holes, the event horizon, gravitational phenomena external to the event horizon, and most of what goes on inside the event horizon. What it does not explain is what goes on deep inside the event horizon where quantum effects are believed to be important. Neither does available quantum theory explain that regime, because gravitational effects as well as quantum effects are important. We have no currently available theory that can handle gravitational effects and quantum effects simultaneously.

    NOBODY,most certainly including you, knows what goes on in the center of a black hole. Your assertion that "That leaves a spinning ball of particles in the centre of a black hole" is demonstration of profound ignorance and equally profound stupidity. As usual, you don't know what in the hell you are talking about. Your positive statements in the face of a complete lack of scientific support are proof positive.

    No one said that the center of a black hole is not part of spacetime. What was said is that the singularity predicted by general relativity cannot be part of spacetime -- quite a different thing. the singular nature of spacetime near the center is an indication that general relativity is not a good description of the real physics -- the theory breaks down. So your statement merely adds to the mounting evidence of your ignorance.

    Who, other than you has ever referred to a spinning event horizon ? A black hole has an angular momentum, possibly zero. It also has mass and electric charge. The no hair theorem shows that those parameters are enough to characterize a black hole within general relativity, i.e. outside of quantum effects. But that has nothing to do with a spinning event horizon. The evidence of ignorance mounts.

    The orbit of a satellite orbiting the earth is essentially independent of the fact that the earth is spinning. There is a predicted effect of general relativity, the Lens-Thirring effect, commonly known as frame dragging, but that effect is so small that it is not agreed as having been yet detected.Moreover, ordinary Newtonian models are more than adequate to describe satellite orbits, and rotation of the earth [plays no part whatever in those calculations. So once again you assertions added to the evidence of your ignorance.

    No one has "dumped non-spinning black holes." What is true is that most black holes are thought to have non-zero angular momentum, just as do most if not all stars. However your assertion that "Every massive thing in space spins, so they were ridiculous, based on the idea that a singularity cannot spin" is just more evidence of ignorance since a singularity is not even a physical thing. Talking about the spinning or non-spinning of a singularity is meaningless word salad.

    If you are not embarrassed by your post, then you should be. However, that probably requires more perspicuity than you can muster. If you are to have any hope of not making yourself look more foolish than you have already done, you will have to educate yourself. that will require more than reading and misunderstanding popularizations and Wiki articles. You would have to actually comprehend the content of some serious physics texts.

    Here are some good ones.

    First you need to come to grips with freshman physics (for things like Newtonian gravity and the elements of orbits) For that I suggest The Feynman Lectures on Physics by Feynman, Leighton and Sands.

    For general relativity, black holes and singularities try

    1) The Mathematical Theory of Black Holes -- Chandrasekhar

    2) Gravitation -- Misner, Thorne, and Wheeler

    3) The large scale structure of space-time -- Hawking and Ellis

    4) General Relativity -- Wald

    5) Spacetime Singularities, An Introduction -- Naber

    6) The Analysis of Space-Time Singularities -- Clarke
     

  54. #53 smearing out the speed of light? 
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    Here I am going to show that the speed of light is constant and it is not. Most of the contents here are taken from the book: Kitty Ferguson. (1991) S.Hawking, Quest for a theory of everything. p.112-114. If I make own comments ore assumptions, I will mark that clearly.


    S.Hawking:
    Traveling back into the very early universe, as space becomes more and more compressed, there are fewer possible choices about where a particle is (its position) at a given moment. The position becomes a more and more precise measurement. Because of the uncertainty principle this causes the measurement of the particle's velocity to become less and less precise.

    First let's look at the photon, the particle of light, under more normal Circumstances. I've told you that photons move at 186.000 miles (300.000 kilometers) per second, making the speed of light 186.000 miles (300.000 kilometers) per second. Now I have to tell you that this might not always be the case. (Having read this far, you are accustomed to such reversals!) Photons, like electrons, can't simultaneously be pinned down precisely as to both position and velocity, because of the uncertainty principle. You leaned that the probability of finding an electron is spread out over some region around the nucleus of an atom: more likely at some distance than others, but definitely a very smeary affair.

    Just so, Richard Feynman and others have told us that the probability that a photon is traveling at 186.000 miles (300.000 kilometers) per second may be spread out over some "region" around that speed. That's the same as saying that in one way of thinking about it, the speed of a photon fluctuates more or less around what we call light speed. Over long distances probabilities cancel out, so as to make the speed of a photon 186.000 miles (300.000 kilometers) per second. However, over very small distances, on the quantum level, there's a possibility that a photon may move at slightly less or slightly more than this speed. These fluctuation won't be seen directly, but the path of photons on the spacetime diagram, which we've drawn at a 45-degree angle. get a little fuzzy.

    When we're studying the very early universe, when space is very compressed, that line gets very fuzzy. The uncertainty principal means that the more precisely we measure the position of a photon, the less precisely we are able to measure it's velocity. When we say that in the very early universe everything was packed to near-infinite (not a singularity, but nearly there). we're becoming extraordinary precise about the locations of particles such as photons. When we are that precise about position, our imprecision about velocity vastly increases. As we near infinite density we also get near an infinite number of possibilities of what the speed of a photon is. What happens to our spacetime diagram now? Look at figure 7-8. The would line of a photon that in more normal circumstances is shown as a 45-degree angle becomes terribly smeared out. It fluctuates and ripples widely.


    Figure 7-8.
    -----------------------------------

    my own comments and conclusions:
    So, what we can see? On the large level the speed of light is an average value that is exactly constant. When we look closer and regard the uncertainty principle we will find that the lightspeed (the would line of the photon) must fluctuate around the average value, the fluctuation is not large but there is one. So it can be said that under normal circumstances the speed of light is never constant, it fluctuates around the known value of 186.000 miles (300.000 kilometers) per second. We have some kind of impression or imagination in our daily live and regard the speed of light as to be constant. We simply cannot see it.

    The whole thing gets more extreme at very high density of matter. In this case the would-line of the photon fluctuates widely! We lose the basic distinction between space and time. So we can not talk about speed anymore. The definition of speed is the quotient of the distance in space and time. But if the distinction get lost we cannot really talk about speed. What a huge statement! :wink:


    greetings
     

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    Hey Yogi. When I debate with other creationists, they always assure me that they have the whole truth too and are just as accurate as you are.

    Large scale structure as in you keep adding mass and the event horizon keeps getting bigger. The gravity phenomena as in up by many magnitudes what happens when a planet rotates and you have what happens with space around a black hole. Nearly as hard as 1+1.

    There are quantum effects with a singularity? Do tell.

    Quantum gravity still a non starter?

    NOBODY,most certainly including you, knows what goes on in the center of a black hole. Your assertion that "That leaves a spinning ball of particles in the centre of a black hole" is demonstration of profound ignorance and equally profound stupidity.
    You just proved that you are not smarter than the average bear by contradicting yourself.

    Your positive statements in the face of a complete lack of scientific support are proof positive.
    Why don't you prove me wrong by showing fundamental particles being completely destroyed? It should be easy enough from the way you rant about it.

    A black hole is not an inert area; a solid ball that you can safely stand within a foot of. That is because it is part of spacetime. The gravity and rotation of the central mass affects nearby space, so is a part of spacetime. You parrot all this stuff without having a clue as to what you are saying.

    Again you say that the theory breaks down while assuring me that nobody knows what goes on at the centre of a black hole. Can you not see that such contradictory statements make you look ridiculous?

    Event horizons on SMBH's have been shown to spin at near light speed. Don't you read anything?

    The evidence of ignorance mounts.
    Indeed it does, Yogi.

    Tell me where an accretion disk is relative to a black hole. Is it near the equator where it spins or the poles where we get poles of powerful magnetic fields and superluminal jets from (outside of)?

    So once again you assertions added to the evidence of your ignorance.
    Wait till I tell Ranger Smith about you. Back to school "dumber than the average bear."

    Show me one massive single stellar or planetary object in space that does not spin. Even galaxies spin.

    Yes a singularity is just an unproven mathematical idea so does not spin or anything else.

    What books did you read to come out with such tripe? Too many pic-a-nic baskets instead of reading I think.

    Pop. Ssssssssss! That's you deflated.
     

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    Quote Originally Posted by MigL
    I would also like to add that the event horizon IS space/time curved in on itself, and according to GR the gravity comes from the curvature imparted to space/time by gravitational collapse of the massive star, not the possible singularity inside.
    So not just a point where the escape velocity is greater than light so light cannot escape from it?

    If spacetime can be dragged around even by a tiny mass like the Earth, imagine what (call it) a trillion Earth gravities could do with it?

    If you assign properties to spacetime, as in gravity can affect it, you must then go with the consequences. If spacetime can be casually dragged around and expand endlessly, a black hole can drag it in like a vacuum tube introduced into a room full of gas. It would literally hoover up spacetime.

    Black holes were first postulated as solutions to GR, the simplest case being non-rotating, by Swartzchild during WW1. The rotating solution, being much more difficult, is attributed to Kerr, I believe, and came much later. The fact that we may never actually come across a non rotating black hole is inconsequential.
    If you have a one dimensional singularity, it cannot spin so a non rotating black hole. However, they all spin. If they did not you would not have spacetime being dragged around by them and infalling matter would seek the quickest path into it, a straight line, so no accretion disk.
     

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    Christian_P. Regarding light having a constant speed, what we really need to know is why it travels at the speed it does (in a vacuum)? If we knew that we would know if the conditions had ever changed so to change "the speed of light".
     

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    Quote Originally Posted by Cyberia
    So not just a point where the escape velocity is greater than light so light cannot escape from it?
    Proving that you are also clueless as to the meaning of "escape velocity".

    Escape velocity, relative to a mass M and a point in space, is the velocity required to be imparted to a mass m, such that the kinetic energy is just equal to the energy required to move m against the gravity of M from the initial point to a point infinitely farther from M.

    Is there even the slightest bit of physics that you might actually understand ?

    Quote Originally Posted by Cyberia
    If spacetime can be dragged around even by a tiny mass like the Earth, imagine what (call it) a trillion Earth gravities could do with it?
    The Lens-Thirring effect, aka frame dragging, has NOTHING to do with "dragging spacetime". Spacetime cannot be dragged, and the notion is not just impossible, but nonsensical.

    This is ridiculous. You are juxtaposing words without meaning, and making a complete fool of yourself.

    Quote Originally Posted by Cyberia
    If you assign properties to spacetime, as in gravity can affect it, you must then go with the consequences. If spacetime can be casually dragged around and expand endlessly, a black hole can drag it in like a vacuum tube introduced into a room full of gas. It would literally hoover up spacetime.
    But of course it cannot be dragged about and you have no idea what you are talking about.

    Quote Originally Posted by Cyberia
    If you have a one dimensional singularity, it cannot spin so a non rotating black hole. However, they all spin. If they did not you would not have spacetime being dragged around by them and infalling matter would seek the quickest path into it, a straight line, so no accretion disk.
    Word salad. Gibberish.

    You have managed to screw up every physical concept that you have so much as mentioned. Ignorance of this breadth and depth is unique.
     

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    Quote Originally Posted by Cyberia
    Christian_P. Regarding light having a constant speed, what we really need to know is why it travels at the speed it does (in a vacuum)? If we knew that we would know if the conditions had ever changed so to change "the speed of light".
    In my opinion the question if the speed of light was ever constant or not (on a large scale) is pure nonsense. There are so many very clever people in this world and non one has ever pointed out that this could be the case. You really think you can find the answer?
    it is simply a wast of time thinking about such nonsense. :-D
     

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    Quote Originally Posted by DrRocket
    Proving that you are also clueless as to the meaning of "escape velocity".

    Escape velocity, relative to a mass M and a point in space, is the velocity required to be imparted to a mass m, such that the kinetic energy is just equal to the energy required to move m against the gravity of M from the initial point to a point infinitely farther from M.
    How about the moving of mass M. That normally requires fuel which also needs to be moved so unless you factor it into the equation, it is not going to work. I have yet to hear of anything just having velocity imparted to it. How does that work? Does god give it a shove (you being from the amen brigade of course believe in god).

    Define "infinitely further"? It sounds to me like you're talking about a trip around the universe or similar rather than beyond the gravity pull of said point in space.


    If spacetime can be dragged around even by a tiny mass like the Earth, imagine what (call it) a trillion Earth gravities could do with it?
    The Lens-Thirring effect, aka frame dragging, has NOTHING to do with "dragging spacetime". Spacetime cannot be dragged, and the notion is not just impossible, but nonsensical.

    This is ridiculous. You are juxtaposing words without meaning, and making a complete fool of yourself.[/quote]

    Explain the accretion disk of a black hole.

    But of course it cannot be dragged about and you have no idea what you are talking about.
    Explain the fact that things do not casually fall in a straight line into a gravity well?

    Word salad. Gibberish.

    You have managed to screw up every physical concept that you have so much as mentioned. Ignorance of this breadth and depth is unique.
    Back to no answers. Just insults. Surely there must be some internet site you can quote from, in your own words?
     

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    Quote Originally Posted by Christian_P
    In my opinion the question if the speed of light was ever constant or not (on a large scale) is pure nonsense. There are so many very clever people in this world and non one has ever pointed out that this could be the case. You really think you can find the answer?
    it is simply a wast of time thinking about such nonsense. :-D
    Light moves at a constant speed through a set medium, with it travelling through glass can be 2/3 of the speed it travels through space.

    We have found Bose Einstein Condensates which will slow down light and even stop it but these are very special conditions.

    Apart from the very early universe, it has since been pretty much as it is now so I cannot see why light would travel slower, except in dust clouds and the like where it may be absorbed and emitted in some cases. The speed of light is accepted as constant until we find out otherwise.
     

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by DrRocket
    Proving that you are also clueless as to the meaning of "escape velocity".

    Escape velocity, relative to a mass M and a point in space, is the velocity required to be imparted to a mass m, such that the kinetic energy is just equal to the energy required to move m against the gravity of M from the initial point to a point infinitely farther from M.
    How about the moving of mass M. That normally requires fuel which also needs to be moved so unless you factor it into the equation, it is not going to work. I have yet to hear of anything just having velocity imparted to it. How does that work? Does god give it a shove (you being from the amen brigade of course believe in god).
    How the mass achieves escape velocity is inconsequential. For a planet, it could have started at a much closer distance and been slowly accelerated as it climbed, or it could received a sudden influx of energy from some external source. All that matters is that at the given point, it has sufficient velocity.


    Define "infinitely further"? It sounds to me like you're talking about a trip around the universe or similar rather than beyond the gravity pull of said point in space.
    In this case, infinite distance means a theoretical infinite distance. It again, is inconsequential as to whether or not the extent of the universe is actually infinite or not. Mathematically, it is when the object's kinetic energy(mv≤/2) and its gravitational potential (-GMm/d) sums to zero.



    Explain the accretion disk of a black hole.
    Conservation of angular momentum for in-falling material



    Explain the fact that things do not casually fall in a straight line into a gravity well?
    Again, conservation of angular momentum. For an object to fall in a straight line it must start with exactly zero angular momentum with respect the the point is falling towards. Since it is extremely unlikely for an object to have exactly zero angular momentum, you are not likely to see objects falling in a straight line.
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    Quote Originally Posted by Janus
    How the mass achieves escape velocity is inconsequential. For a planet, it could have started at a much closer distance and been slowly accelerated as it climbed, or it could received a sudden influx of energy from some external source. All that matters is that at the given point, it has sufficient velocity.

    In this case, infinite distance means a theoretical infinite distance. It again, is inconsequential as to whether or not the extent of the universe is actually infinite or not. Mathematically, it is when the object's kinetic energy(mv≤/2) and its gravitational potential (-GMm/d) sums to zero.
    My point here is that it's a dumb-assed way of saying the obvious.

    [/quote]Conservation of angular momentum for in-falling material[quote]

    That would suggest that all material that falls into a black hole does it from an angle and in the plane of what we would call the equator of the black hole.


    Again, conservation of angular momentum. For an object to fall in a straight line it must start with exactly zero angular momentum with respect the the point is falling towards. Since it is extremely unlikely for an object to have exactly zero angular momentum, you are not likely to see objects falling in a straight line.
    Things would approach a black hole from all directions and all angles yet an accretion disk is an orderly infalling of material by one pathway.
     

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by Janus
    How the mass achieves escape velocity is inconsequential. For a planet, it could have started at a much closer distance and been slowly accelerated as it climbed, or it could received a sudden influx of energy from some external source. All that matters is that at the given point, it has sufficient velocity.

    In this case, infinite distance means a theoretical infinite distance. It again, is inconsequential as to whether or not the extent of the universe is actually infinite or not. Mathematically, it is when the object's kinetic energy(mv≤/2) and its gravitational potential (-GMm/d) sums to zero.
    My point here is that it's a dumb-assed way of saying the obvious.
    No, I don't think you ever had a point.
    Conservation of angular momentum for in-falling material

    That would suggest that all material that falls into a black hole does it from an angle and in the plane of what we would call the equator of the black hole.


    Again, conservation of angular momentum. For an object to fall in a straight line it must start with exactly zero angular momentum with respect the the point is falling towards. Since it is extremely unlikely for an object to have exactly zero angular momentum, you are not likely to see objects falling in a straight line.
    Things would approach a black hole from all directions and all angles yet an accretion disk is an orderly infalling of material by one pathway.
    The matter forming an accretion disc comes from material in the vicinity of the BH. It can come from the other star in a x-ray binary or in the case of a galactic black hole, from material lfe over after the initial formation. The BH and in-falling material was formed from material that already has basically the same direction of rotation. So in-falling material already has a preferred direction. Just like the original cloud that formed the proto-planetary disk that became the Solar system. did.
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    Material heading towards a black hole will come from anywhere in the vicinity and may have any form of momentum as it comes from any direction.

    You have a cloud of gas and material from a previous super nova. A super nova goes off nearby and the shock wave starts off the process of creating a solar system. Why should a proto planetary disk which rotates form? Why not like water vapour coalescing in the air and around dust and so forming rain droplets? Why the disk and why the spin? Why not just a cloud of planets, moons and a star?
     

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    Quote Originally Posted by Cyberia
    Material heading towards a black hole will come from anywhere in the vicinity and may have any form of momentum as it comes from any direction.

    You have a cloud of gas and material from a previous super nova. A super nova goes off nearby and the shock wave starts off the process of creating a solar system. Why should a proto planetary disk which rotates form? Why not like water vapour coalescing in the air and around dust and so forming rain droplets? Why the disk and why the spin? Why not just a cloud of planets, moons and a star?
    Why does water circle the drain?
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by Cyberia
    Material heading towards a black hole will come from anywhere in the vicinity and may have any form of momentum as it comes from any direction.
    As usual, this contradicts consolidated scientific knowledge.
    Quote Originally Posted by Cyberia
    You have a cloud of gas and material from a previous super nova. A super nova goes off nearby and the shock wave starts off the process of creating a solar system.
    This is a possible trigger for star formation, but was never actually proven. Why do you keep quoting published scientific paradigms whenever they suit you, but deny established firm science for which hard evidence exists?
    Quote Originally Posted by Cyberia
    Why should a proto planetary disk which rotates form? Why not like water vapour coalescing in the air and around dust and so forming rain droplets? Why the disk and why the spin? Why not just a cloud of planets, moons and a star?
    This is because of friction of the material and initial turbulence within the parental starforming clouds (this is an established fact backed up by observations). Not the entire cloud collapses, but it fragments, and so the momentum of the turbulence is randomly distributed across the individual collapsing cores. The net momentum can transform into rotation due to friction and drag effects witin the material. While they shrink, their rotation speeds up (conservation of momentum). Rotation creates a centrifugal force that acts against the gravitational pull. The remaining matter falls onto the forming disk and the evolving protostar.
     

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    Quote Originally Posted by Dishmaster
    Quote Originally Posted by Cyberia
    Material heading towards a black hole will come from anywhere in the vicinity and may have any form of momentum as it comes from any direction.
    As usual, this contradicts consolidated scientific knowledge.
    And the observed strucuture of galaxies, and the discipline of celestial mechanics necessary to understanding galactic structure. I suspect that it comes from confusing black holes with vacuum cleaners -- as though physics owed more to Hoover than Einstein and Newton.
     

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    Quote Originally Posted by KALSTER
    Why does water circle the drain?
    Because it comes in on a plane with the drain and because the Earth rotates and it is in physical contact so to speak with the Earth.
     

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    [quote="Dishmaster"]As usual, this contradicts consolidated scientific knowledge.

    Are you saying that matter approaching a black hole before it reaches the pull of the accretion disk will only do so along the equator of the black hole?

    This is a possible trigger for star formation, but was never actually proven. Why do you keep quoting published scientific paradigms whenever they suit you, but deny established firm science for which hard evidence exists?
    Astronomy has lots of hard evidence. Cosmology which is a totally different field does not.

    This is because of friction of the material and initial turbulence within the parental starforming clouds (this is an established fact backed up by observations). Not the entire cloud collapses, but it fragments, and so the momentum of the turbulence is randomly distributed across the individual collapsing cores. The net momentum can transform into rotation due to friction and drag effects witin the material. While they shrink, their rotation speeds up (conservation of momentum). Rotation creates a centrifugal force that acts against the gravitational pull. The remaining matter falls onto the forming disk and the evolving protostar.
    You have random momentum transforming into rotational momentum. Not much friction in space but surely drag would be evenly distributed, so no net effect?
     

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    Quote Originally Posted by DrRocket
    And the observed strucuture of galaxies, and the discipline of celestial mechanics necessary to understanding galactic structure. I suspect that it comes from confusing black holes with vacuum cleaners -- as though physics owed more to Hoover than Einstein and Newton.
    Lots of hand waving but no answers. Even Genesis has answers according to the late but not great Henry Morris.
     

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by DrRocket
    And the observed strucuture of galaxies, and the discipline of celestial mechanics necessary to understanding galactic structure. I suspect that it comes from confusing black holes with vacuum cleaners -- as though physics owed more to Hoover than Einstein and Newton.
    Lots of hand waving but no answers. Even Genesis has answers according to the late but not great Henry Morris.
    That is only because you are too stupid to recognize the answer in terms if basic physics. Blach holes in spiral galaxies are already in a region with a dominant angular momentum component, moron.
     

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by KALSTER
    Why does water circle the drain?
    Because it comes in on a plane with the drain and because the Earth rotates and it is in physical contact so to speak with the Earth.
    Are you thinking of that thing that says water circle the drain in opposite directions on either side of the equator? Because that is nonsense. The spinning of the earth has nothing to do with the direction of spin of water circling a drain or even that it "chooses' a direction at all.

    The point is that just as water circling a drain has a small bias determined by initial conditions that then pulls the rest of the water along as it speeds up under gravity in the direction of the centre of mass, so does a collapsing matter cloud. With the matter cloud it just happens in 3D. Since the dominating rotation is planar in character, so must the average rotation of the matter cloud also be eventually. The orientation of the plane of rotation is randomly "chosen" by the initial conditions.

    The vast majority o0f matter that would come into contact with an event horizon would be part of the accretion disc and so will have a very high probability of approaching it in the same plane as the plane of rotation of the black hole that is itself the product of the accretion disc. But if you flew in a spaceship from outside of the black hole, you can approach from where ever you wished. Similarly, of you aimed an asteroid from a point an outside point right at the north pole of the event horizon (and if it doesn't get affected too much by other matter along the way) it will cross the event horizon very close to north pole.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by Dishmaster
    This is because of friction of the material and initial turbulence within the parental starforming clouds (this is an established fact backed up by observations). Not the entire cloud collapses, but it fragments, and so the momentum of the turbulence is randomly distributed across the individual collapsing cores. The net momentum can transform into rotation due to friction and drag effects witin the material. While they shrink, their rotation speeds up (conservation of momentum). Rotation creates a centrifugal force that acts against the gravitational pull. The remaining matter falls onto the forming disk and the evolving protostar.
    You have random momentum transforming into rotational momentum. Not much friction in space but surely drag would be evenly distributed, so no net effect?
    You try so hard to misunderstand. Right? What I meant was that the turbulence in molecular clouds is randomly distributed. So, there are small parts that have one dominant direction of the matter flow, and there are others that have another direction and velocity. The net effect is basically zero on large scales like the entire cloud. But it is not zero for localised cores that fragment. Therefore, each fragment contains a bit of the turbulence cells. The net momentum of the collapsing cores cannot be zero, because otherwise they would not collapse. The collapse is triggered by a local enhancement of the density which is caused by matter streams that collide and produce an overabundance of gas and dust as compared to other regions in the cloud.
     

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    Quote Originally Posted by DrRocket
    That is only because you are too stupid to recognize the answer in terms if basic physics. Blach holes in spiral galaxies are already in a region with a dominant angular momentum component, moron.
    What has this got to do with black holes and SMBH's hoovering up dark matter? Is this some more of your hand waving?

    I have told you before that there is no need to sign your posts as everyone knows you are a moron.
     

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    KALSTER. As someone remarked about The Simpsons episode years back, direction of flow and hemispheres only applies to large bodies of water. Not toilets.

    An easy experiment. Fill a sink full of water and take the plug out of the water and a whirlpool quickly forms. Now with a full sink remove the plug slowly and don't take it out of the water but just to the right of the drain and after a while, that is where the whirlpool will start. The same if to the left of the drain. You cause that bias.

    But this could not work with a black hole because they have periods of inactivity. Then something comes too near and we get an accretion disk. But assuming it could come from any direction, why would it form an accretion disk around the equator if as you say you could fly a spaceship or asteroid in via one of the poles?
     

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    Quote Originally Posted by Cyberia
    I have told you before that there is no need to sign your posts as everyone knows you are a moron.
    You seem to have me confused with someone who cares what you think, if you think.
     

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    Dishmaster. I question EVERYTHING. I do not casually accept anything as true. Isn't that what science is supposed to be?

    The thing about such clouds is that they are very large as in maybe thousands of light years in diameter. To create a bias, it needs something very violent nearby like a supernova going off. A comet going through the cloud (over millions of years) is just not going to do it.
     

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    Quote Originally Posted by DrRocket
    You seem to have me confused with someone who cares what you think, if you think.
    You seem to have confused your ability to quote from sources and to mention books you have clearly not read with intellect.
     

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by DrRocket
    You seem to have me confused with someone who cares what you think, if you think.
    You seem to have confused your ability to quote from sources and to mention books you have clearly not read with intellect.
    wrong

    You have no idea what I have read. I have not only read, but own each of the references that I have supplied to you.
     

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    Quote Originally Posted by Cyberia
    Dishmaster. I question EVERYTHING. I do not casually accept anything as true. Isn't that what science is supposed to be?
    nope

    Science certainly involves critical thinking. But it also involves understanding of the logical basis for mainstream theories -- which is where you fail miserably.

    Critical thinking is not simple denial. There is a reason why accepted theories are accepted -- within a known domain of validity. Research involves working beyond the known domain of validity to develop better theories, but it is not just quoting pop science nonsense out of context.

    You have demonstrated total lack of understanding of even freshman physics, and have no idea what you are talking about. You don't even understand that you don't understand -- always wrong, but never uncertain.
     

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    Then something comes too near and we get an accretion disk. But assuming it could come from any direction
    Why assume that? The vast majority of mater that would encounter a black hole will already be in the plane of rotation of the black hole.

    why would it form an accretion disk around the equator if as you say you could fly a spaceship or asteroid in via one of the poles?
    In this context there is a pretty big difference between "it" and enough matter to form an accretion disc.

    Let's for the sake of argument take a situation where a "clean" black hole slowly migrates into a large cloud of matter. I am not sure what the models show, but I would imagine that a large amount of matter would approach the black hole from all angles initially, but matter that falls past the event horizon a few times would eventually also form a disc along the plane of rotation. I imagine that a rotating black hole, with or without gravitational imbalances, i.e. even with a disc-shaped singularity, would still get the matter cloud rotating along with it eventually.

    For this imagine a disk submerged in water. If you start rotating the disc, pretty soon the water above and below it will start rotating in the same direction. Matter above the black hole would start falling in a spiral towards it, the size of the spiral depending on the speed of rotation. Smaller spirals will encounter the event horizon on the first pass, while bigger ones will have an opportunity to fall less farther past the plane on each pass as the gravitational pull of the black hole transforms some vertical momentum into horizontal momentum. With a big cloud you will eventually have an accretion disc with components with roughly stable orbits.

    Or so I imagine anyway. Maybe Dishmaster knows of a model that could show some light on the issue.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by Cyberia
    The thing about such clouds is that they are very large as in maybe thousands of light years in diameter. To create a bias, it needs something very violent nearby like a supernova going off. A comet going through the cloud (over millions of years) is just not going to do it.
    The average class molecular cloud has diameters of a few to a dozens of parsec, surely not thousands of light years. You are confusing interior turbulence with external possible triggers (which I have stated already are not proven to work efficiently). They are not needed to start the star formation process. Turbulence can be induced by gravitational and tidal interaction with the galaxy as a whole, external stellar radiation fields or the outflows of already forming stars inside the cloud. Of course, I was not thinking about comets - that's silly. It must be something far more energetic than this.
     

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    Quote Originally Posted by Cyberia
    Dishmaster. I question EVERYTHING. I do not casually accept anything as true.
    This brings to mind a quote from [u]The Notebooks of Lazarus Long[/i] by Heinlein:

    "You can go wrong by being too skeptical as readily as by being too trusting."

    Apparently, this is the path you have decided to take.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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    Quote Originally Posted by DrRocket
    wrong

    You have no idea what I have read. I have not only read, but own each of the references that I have supplied to you.
    But you seem unable to give any information from any of them, restricting your posts to denial and insults. I am sure those books contain more than that.
     

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    Quote Originally Posted by DrRocket
    You have demonstrated total lack of understanding of even freshman physics, and have no idea what you are talking about. You don't even understand that you don't understand -- always wrong, but never uncertain.
    As your posts to me are just denial and insults, this is just a baseless opinion you have, which I will ignore.
     

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    Quote Originally Posted by KALSTER
    Why assume that? The vast majority of mater that would encounter a black hole will already be in the plane of rotation of the black hole.
    Originally yes but over time it will absorb all nearby matter so will later take in whatever strays too close to it from anywhere else.

    Let's for the sake of argument take a situation where a "clean" black hole slowly migrates into a large cloud of matter. I am not sure what the models show, but I would imagine that a large amount of matter would approach the black hole from all angles initially, but matter that falls past the event horizon a few times would eventually also form a disc along the plane of rotation. I imagine that a rotating black hole, with or without gravitational imbalances, i.e. even with a disc-shaped singularity, would still get the matter cloud rotating along with it eventually.
    In this instance yes, where all the matter is "connected" it will start a flow that will slowly drag in everything else the same way and so accentuate the effect.

    If there was sufficient matter, would an accretion disk form or a whirlpool, as in water? I know in such cases black holes are said to be "messy eaters" and can lose upto to 90% of the matter.

    I was originally thinking random pieces of matter over time.[/quote]
     

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    Quote Originally Posted by Janus
    Quote Originally Posted by Cyberia
    Dishmaster. I question EVERYTHING. I do not casually accept anything as true.
    This brings to mind a quote from [u]The Notebooks of Lazarus Long[/i] by Heinlein:

    "You can go wrong by being too skeptical as readily as by being too trusting."

    Apparently, this is the path you have decided to take.
    I never got round to reading that.

    The thing about cosmology as compared to any other science if I can call cosmology that is that much of it is taken on trust with a number of the very basic principles being no more than ideas.
     

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    Quote Originally Posted by Cyberia
    The thing about cosmology as compared to any other science if I can call cosmology that is that much of it is taken on trust with a number of the very basic principles being no more than ideas.
    Utterly wrong, as has been explained to you over and over again.

    Cosmology is based on general relativity, with a dash of high-energy physics.

    You understand less than nothing of modern cosmology. Go read the books that have been recommended to you.
     

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    Quote Originally Posted by DrRocket
    Utterly wrong, as has been explained to you over and over again.

    Cosmology is based on general relativity, with a dash of high-energy physics.

    You understand less than nothing of modern cosmology. Go read the books that have been recommended to you.
    No explanation of how the singularity (or whatever) formed or how it got there or being ultimately stable how it inflated (unproven idea) then switched to expansion, in four or more physical dimensions (unproven idea), etc.

    It is based on speculation as you would know if you did anything but spout mindless dogma.

    Are you still colouring in your first Janet and John book?
     

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    Quote Originally Posted by Cyberia
    Quote Originally Posted by DrRocket
    Utterly wrong, as has been explained to you over and over again.

    Cosmology is based on general relativity, with a dash of high-energy physics.

    You understand less than nothing of modern cosmology. Go read the books that have been recommended to you.
    No explanation of how the singularity (or whatever) formed or how it got there or being ultimately stable how it inflated (unproven idea) then switched to expansion, in four or more physical dimensions (unproven idea), etc.

    It is based on speculation as you would know if you did anything but spout mindless dogma.

    Are you still colouring in your first Janet and John book?
    gibberish

    No one (except you) has ever claimed that any singularity ever expanded.

    You continually demand answers to such meaningless juxtapositions of words. Since you have not even expressed a viable thought, a cogent answer is an irrational expectation.

    You are delusional

    Since you have elsewhere stated that by "physical dimensions" you mean spatial dimensions, your question proves that you don't understand anything of cosmology as reflected in general relativity. In that model there are only 3 spacelike dimensions in any chart. So whatever it is that you mean by "expansion, in four or more physical dimensions" is a product of your personal delusion, but not germane to mainstream cosmology. Such misonceptions accwntuate your ignorance and need to read a real book on cosmology.
     

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    This thread has lost its ways since it was started. Therefore, I decided to lock it, since nobody seems to have to add anything to the initial question.

    Dishmaster
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