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Thread: A Forever Expanding Universe - Our Point of Reference?

  1. #1 A Forever Expanding Universe - Our Point of Reference? 
    Forum Freshman hadams's Avatar
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    This is kind of something I've been chewing on since watching Richard Dawkins' and Lawrence Krauss' discussion "Something From Nothing" (here), and a lecture given by Krauss on how we live in an open, expanding universe (here). What I found most challenging to understand - particularly in the latter lecture - is that the universe is expanding and accelerating: everything is moving further and further apart, at a faster and faster rate.

    The first question that popped into my mind (and, if I remember correctly, Krauss brings this up too) was: how could any post-human race make any accurate determinations based on observational evidence, if everything they will observe will lead them to the conclusion that they are, in fact, alone in the universe? Eventually everything will be far enough away from everything else that we (or they?) won't be able to observe it from earth. All of their observations would lead them to believe that we're alone, right? And they would be as certain of it as we were of our paradigms regarding the universe in the 19th century (and I think the paradigms themselves would be very similar). It made me question whether there's a possibility that we could be absolutely wrong about everything (I know, but just entertain the thought for a second). What if all our observational evidence is wrong and everything we hypothesize just so happens to line up with how it looks like things panned out? I know this latter question is a little outrageous but I wanted to hear what you guys have to say.

    A thought that occured to me a little while after came as I was reading Dawkins' "The Greatest Show On Earth", where there was a mention that our brains are getting bigger, on a macro-evolutionary scale. Then I thought about the five major catastrophes that wiped out life almost completely each time ... almost completely. It was the 5% of animals that survived the Cretaceous-Tertiary Mass Extinction that led to our eventual coming into existence, and it made me wonder ... if the death of our sun is the next mass-extinction, could it be that if a percentage of humans survive it, the development of our brains/intelligence/technology at that stage would have come so far that we would save ourselves from such a colossal misunderstanding of the future universe?

    Sorry if that was a little convoluted. I hope it made sense. I'd love to get your thoughts on it as physicists. I'm only good for sitting and thinking about stuff, really.


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  3. #2  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Even in such circumstances, our ideas wouldn't be completely wrong, only incomplete. Gravity wouldn't suddenly work differently for example. (This is based on the correspondence principal.)


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    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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    I don't like the idea of human extinction scenarios, anthropogenic or natural causes. But it is inevitable.
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    ~ At a base level there is a view that some of what you have said 'you think' might be a truth we have yet to establish. As has been mentioned the death of SOL is a long way off yet and that 'other' mass extinction events could be our undoing.. Meteoric impacts or just a massive volcanic caldera event could bring humanities reign to a untimely end.. Those things Mr's Dawkins and Krauss are as our understanding allows. The cutting edge of our understanding of the Universe. Let it be clear that the eventual cold death of the expanding Universe into a cold sparse place is not just Hundreds of billions of years away but billions of billions.. No end is predicted such as a expansion can be imagined..
    Your point to of and as, "could we be wrong ?".. YES. The scientific method demands the subject is never closed. Events and probabilities remain as theory and hypothesis always.. New information can sweep all before it. You make a good point and one well worthy of consideration. and, Welcome..
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  7. #6  
    Forum Freshman hadams's Avatar
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    Even in such circumstances, our ideas wouldn't be completely wrong, only incomplete. Gravity wouldn't suddenly work differently for example. (This is based on the correspondence principal.)
    I see your point, but I think it has little to do with the question I was asking. Even though our laws and constants would be the same, our observational evidence of the works of these laws will be so vastly limited that ... now that I think about it, it may not even be possible to identify some of them when everything is at that distance. It could lead to some serious goose chases.

    I don't like the idea of human extinction scenarios, anthropogenic or natural causes. But it is inevitable.
    Clair, I'll be honest, it scared the crap out of me when I first thought about it. To think that life here is just a series of birth/existence/death on different scales can make you feel pretty hopeless ... or, it can help you realize what actually matters in your time here. I'm a musician, who was struggling so hard with motivation, trying to decide if it really matters. What I've been learning in physics pulled me right out of it. I won't go into it too much here in terms of how but if there's some kind of philosophy thread ...

    ~ At a base level there is a view that some of what you have said 'you think' might be a truth we have yet to establish. As has been mentioned the death of SOL is a long way off yet and that 'other' mass extinction events could be our undoing.. Meteoric impacts or just a massive volcanic caldera event could bring humanities reign to a untimely end.. Those things Mr's Dawkins and Krauss are as our understanding allows. The cutting edge of our understanding of the Universe. Let it be clear that the eventual cold death of the expanding Universe into a cold sparse place is not just Hundreds of billions of years away but billions of billions.. No end is predicted such as a expansion can be imagined..
    Your point to of and as, "could we be wrong ?".. YES. The scientific method demands the subject is never closed. Events and probabilities remain as theory and hypothesis always.. New information can sweep all before it. You make a good point and one well worthy of consideration. and, Welcome..
    Thank you astro! The only thing I couldn't quite extrapolate your meaning from, in your response, was 'no end is predicted such as a expansion can be imagined'. Do you mean that because the expansion is infinite, no end of the universe can be predicted? Or no end to humanity/our planet?

    ... scary to think that we could be totally wrong. And, if we were obliterated by some catastrophe pre-death-of-the-sun, the pending survival of absolutely anything would determine the future of life? Well, carbon-based life. Life as we know it, etc.

    Somehow I always feel the need to over-justify. Probably a defense mechanism born out of fear of looking completely ridiculous!
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  8. #7  
    Forum Radioactive Isotope MagiMaster's Avatar
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    Quote Originally Posted by hadams View Post
    Even in such circumstances, our ideas wouldn't be completely wrong, only incomplete. Gravity wouldn't suddenly work differently for example. (This is based on the correspondence principal.)
    I see your point, but I think it has little to do with the question I was asking. Even though our laws and constants would be the same, our observational evidence of the works of these laws will be so vastly limited that ... now that I think about it, it may not even be possible to identify some of them when everything is at that distance. It could lead to some serious goose chases.
    (Emphasis mine.) That's my point though. Our observations could be limited, but they're not wrong. That would imply that any theories built on those observations would be similarly limited, but also not "wrong" (as much as a theory can even be right or wrong).
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  9. #8  
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    It is worth mentioning though that even when all the other galaxies are beyond our ability to see, we would still have our own galaxy, which consists out of billions of star systems. I would say that it is improbable that we are alone even in our own galaxy. Also, expansion is nullified at smaller distances, so I think we would still be able to see at least our local group of galaxies for the foreseeable future. Also, Andromeda will be colliding with our galaxy long before the rest of them disappear (which would make a larger galaxy, but not cause much destruction, as one might think).

    Also, I would hazard a guess that we would have been able to overcome our current restriction on interstellar travel. There is a model called the Alcubierre drive for example that, though far from being confirmed as a definite possibility, could see us being able to traverse vast distances at superluminal speeds. We could then in fact catch up with the receding other galaxies.

    Alcubierre drive - Wikipedia, the free encyclopedia
    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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    I really hope the universe is more complex than we think it is, otherwise we'll get bored in 20 million years or so.
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    This relates to the topic because...hmmm he mentioned were gonna die before the sun explodes I wonder if this is because of boredom.
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  12. #11  
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    Last edited by Chucknorium; May 17th, 2014 at 10:32 PM. Reason: wrong thread
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    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
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  14. #13  
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    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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  15. #14  
    Bullshit Intolerant PhDemon's Avatar
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    I get the impression1 Stargate thinks that just because he makes unsupported assertions based on whatever he has just made up that that is what everyone else is doing. He doesn't seem to understand that most of the sane posters here actually know what they are talking about...

    1. OK it's fairly obvious from his anti-science nonsense, more of a Chicxulub crater than an impression.
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  16. #15  
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    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    However, those calculations are speculative since things are changing constantly. Can you definitively say those calculations will be right in one billion years?
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  17. #16  
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    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    However, those calculations are speculative since things are changing constantly. Can you definitively say those calculations will be right in one billion years?
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    It would help your posts if you were to actually learn something, instead of simply shooting off your mouth out of ignorance.
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    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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  18. #17  
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    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    However, those calculations are speculative since things are changing constantly. Can you definitively say those calculations will be right in one billion years?
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    It would help your posts if you were to actually learn something, instead of simply shooting off your mouth out of ignorance.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
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  19. #18  
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    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    However, those calculations are speculative since things are changing constantly. Can you definitively say those calculations will be right in one billion years?
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    It would help your posts if you were to actually learn something, instead of simply shooting off your mouth out of ignorance.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    Do you purposely post non-science just to get a reaction from the scientifically-minded members?
    And then you counter with really stupid and vapid questions.
    And finally you start to whine if your stupid/vapid questions aren't answered.

    Your posting sure seems like troll behavior to me.
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  20. #19  
    Anti-Crank AlexG's Avatar
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    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    However, those calculations are speculative since things are changing constantly. Can you definitively say those calculations will be right in one billion years?
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    It would help your posts if you were to actually learn something, instead of simply shooting off your mouth out of ignorance.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    The laws of physics did not change over time. The speed of light did not change over time. The ratio of primordial hydrogen, helium and lithium do not change over time. The energy of various nuclear reaction do not change over time. The half-life and decay rates of radioactive isotopes do not change over time.

    What do YOU think is changing constantly?
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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  21. #20  
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    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    However, those calculations are speculative since things are changing constantly. Can you definitively say those calculations will be right in one billion years?
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    It would help your posts if you were to actually learn something, instead of simply shooting off your mouth out of ignorance.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    The laws of physics did not change over time. The speed of light did not change over time. The ratio of primordial hydrogen, helium and lithium do not change over time. The energy of various nuclear reaction do not change over time. The half-life and decay rates of radioactive isotopes do not change over time.

    What do YOU think is changing constantly?
    I know many members will tell you that the only thing they know that is constant is change, do you believe that is wrong? Did science prove that change is the only constant?
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  22. #21  
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    Quote Originally Posted by Chucknorium View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    The 'death' of the sun won't occur for about another 5 billion years or so. It's unlikely we'll still be around.
    I think you are speculating, I have been here for how long I do not know. Things fall apart and come together, and BTW always changing. For you to go 5 billion years ahead is dreaming. Please don't go crazy on me on me, if you disagree that's fine.
    No, we know the mass of hydrogen in the sun, we know the rate of nuclear fusion, and we know with a high degree of certainty that in 5 billion years or so, the sun will begin to run out of hydrogen and expand into a red giant. It's called science, something you've demonstrated you know little to nothing about.
    However, those calculations are speculative since things are changing constantly. Can you definitively say those calculations will be right in one billion years?
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    It would help your posts if you were to actually learn something, instead of simply shooting off your mouth out of ignorance.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    Do you purposely post non-science just to get a reaction from the scientifically-minded members?
    And then you counter with really stupid and vapid questions.
    And finally you start to whine if your stupid/vapid questions aren't answered.

    Your posting sure seems like troll behavior to me.
    Make your choice it really does not matter to me.
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  23. #22  
    Anti-Crank AlexG's Avatar
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    I know many members will tell you that the only thing they know that is constant is change, do you believe that is wrong?
    A facile, new age aphorism, mouthed by those who have never studied science of any kind.
    Did science prove that change is the only constant?
    No.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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    Quote Originally Posted by AlexG View Post
    I know many members will tell you that the only thing they know that is constant is change, do you believe that is wrong?
    A facile, new age aphorism, mouthed by those who have never studied science of any kind.
    Did science prove that change is the only constant?
    No.
    Thank you, now we are getting somewhere.
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  25. #24  
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    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    What is wrong with you? Do you just post random opinions without reading what has been said?

    The laws of physics do not change over time.
    ei incumbit probatio qui dicit, non qui negat
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  26. #25  
    AI's Have More Fun Bad Robot's Avatar
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    Quote Originally Posted by MagiMaster View Post
    Quote Originally Posted by hadams View Post
    Even in such circumstances, our ideas wouldn't be completely wrong, only incomplete. Gravity wouldn't suddenly work differently for example. (This is based on the correspondence principal.)
    I see your point, but I think it has little to do with the question I was asking. Even though our laws and constants would be the same, our observational evidence of the works of these laws will be so vastly limited that ... now that I think about it, it may not even be possible to identify some of them when everything is at that distance. It could lead to some serious goose chases.
    (Emphasis mine.) That's my point though. Our observations could be limited, but they're not wrong. That would imply that any theories built on those observations would be similarly limited, but also not "wrong" (as much as a theory can even be right or wrong).
    It's not that the observations are wrong, but the interpretations of those observations could be off base. An example could be the type 1A supernova. For a long time now it was thought that all type 1A's were the same brightness due to being the same size supernova. Now they know that type 1A supernovas can happen when the white dwarf mass is in the range of .9 - 1.4 solar masses, which means they are not all the same brightness. So I'd say that all measurements made based on the type 1A supernovas needs to be recalculated if possible or we find a reasonable way to compensate for those different brightnesses.
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    What is wrong with you? Do you just post random opinions without reading what has been said?

    The laws of physics do not change over time.
    I understand what you are saying to mean the law of physics is a constant? Is that so?
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  28. #27  
    Brassica oleracea Strange's Avatar
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    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by Strange View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    What is wrong with you? Do you just post random opinions without reading what has been said?

    The laws of physics do not change over time.
    I understand what you are saying to mean the law of physics is a constant? Is that so?
    I cannot understand why you are doing this. It isn't funny.
    ei incumbit probatio qui dicit, non qui negat
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  29. #28  
    Anti-Crank AlexG's Avatar
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    He's simply trolling. He has nothing intelligent to say, so he just tries to provoke.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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    Forum Freshman hadams's Avatar
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    Quote Originally Posted by AlexG View Post
    He's simply trolling. He has nothing intelligent to say, so he just tries to provoke.
    It can be SO hard to ignore that kind of deliberate, provocative ignorance but it is a waste of energy. I completely sympathize with your frustration though.

    For a moment I thought he might have been trying to say that things change over time (like the decay of a radioactive isotope), but we are able to measure and predict things like that because of the constancy of the laws of physics. That's why they're called 'laws' and 'constants'.

    ... But then he made that comment about 'the law of physics being constant' and I tuned out as soon as I realized he'd written 'law' as a singular, not to mention the inherent ridiculousness of the statement in general. I think he's just jabbing.
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    Forum Sophomore keeseguy's Avatar
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by Stargate View Post
    Quote Originally Posted by AlexG View Post
    Yes. Things are not 'changing constantly'. The calculations are not speculative. The laws of physics do not change over time. Stellar Nucleosynthesis is a well understood process which, thanks to the nuclear weapons program of the 50's and 60's, are quite extensively tested.
    What do you mean things are not changing constantly? Do you have anything specific that did not change over time?
    What is wrong with you? Do you just post random opinions without reading what has been said?

    The laws of physics do not change over time.
    When discussing intergalactic observations, do we not have to consider that galaxies are moving in space time at an undetermined speed. I have read discussions that hinted at the probability that galactic speeds may be in some respects a reasonable percentage of c. If we are moving 1/2 c would that not distort our observations, or even the rate at which the laws behave. Will the laws of physics all be the same here on earth as they are for in a galaxy moving at a notable speed away from us?
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    Brassica oleracea Strange's Avatar
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    Quote Originally Posted by keeseguy View Post
    When discussing intergalactic observations, do we not have to consider that galaxies are moving in space time at an undetermined speed.
    I'm not sure what you mean by "undetermined". We can measure the relative velocities of galaxies in galactic clusters - this is one evidence for dark matter.

    I have read discussions that hinted at the probability that galactic speeds may be in some respects a reasonable percentage of c.
    Andromeda is approaching the Milky Way galaxy at about 110 km/s (about 0.04% of the speed of light). I assume that is fairly typical for the relative speeds of galaxies. That may not sound like a reasonable percentage of c, but it many times faster than a GPS satellite, where we have to take relativistic effects into account.

    If we are moving 1/2 c would that not distort our observations, or even the rate at which the laws behave.
    Firstly, moving at 1/2 c relative to what? After all, we are already moving at 0.999% c relative to something, somewhere. And the whole point of relativity is that the laws of physics are independent of your state of motion - which is why there is no experiment you can do that will tell you if you are stationary or moving (without reference to some other object to measure that motion against).

    Will the laws of physics all be the same here on earth as they are for in a galaxy moving at a notable speed away from us?
    Yes. This is Lorentz invariance, which may have started as a working assumption for relativity (based on Maxwell's equations) but has now been tested to ludicrous levels of precision.
    ei incumbit probatio qui dicit, non qui negat
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    thanks strange
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