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Did there exist time t = 0?
Hi, SA,
It's commonly asserted that the universe began at time t = 0 with the Big Bang. Is there any evidence for this existence of time t = 0? An alternative is that there exists time t for all t 0, but not t = 0 itself. In this model, time stretches back indefinitely, since it has no boundary, and there is no Big Bang; just that the way we measure it, we compress all t epsilon into a tiny tiny time, possibly artificially. In this latter model, then, the universe has been expanding forever, and the way the cosmos now looks, will carry on expanding forever. -- Alan Mackenzie (Nuremberg, Germany). |
#2
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Did there exist time t = 0?
Dear Alan Mackenzie:
On Feb 28, 9:27*am, Alan Mackenzie wrote: .... It's commonly asserted that the universe began at time t = 0 with the Big Bang. *Is there any evidence for this existence of time t = 0? There is no evidence for time before about 270,000 years after the Big Bang. An alternative is that there exists time t for all t 0, but not t = 0 itself. There is no evidence for time prior to the Big Bang, since time is just another coordinate in this Universe (depending on your Cosmological model), and the Universe did not exist prior to the Big Bang. *In this model, time stretches back indefinitely, since it has no boundary, and there is no Big Bang; just that the way we measure it, we compress all t epsilon into a tiny tiny time, possibly artificially. Unless it makes a quantifiable prediction that allows it to be falsified, it is as useless as what we have now. Why do you waste time positing another "model" that cannot be falsified? In this latter model, then, the universe has been expanding forever, and the way the cosmos now looks, will carry on expanding forever. Oh, so you do make a prediction that is easily falsified. Infinite Universe has a "lack of iron and overabundance of hydrogen" problem. Entropy has not been seen to reverse in a macroscopic scale in the 13+ billion years displayed. Yet stars continue to manufacture heavier and heavier elements, use up their hydrogen "explode" and die. Where is your iron? David A. Smith |
#3
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Did there exist time t = 0?
dlzc wrote:
Dear Alan Mackenzie: On Feb 28, 9:27?am, Alan Mackenzie wrote: ... It's commonly asserted that the universe began at time t = 0 with the Big Bang. ?Is there any evidence for this existence of time t = 0? There is no evidence for time before about 270,000 years after the Big Bang. Then there is no evidence for the Big Bang itself; a steadily expanding universe fits the evidence just as well, does it not? An alternative is that there exists time t for all t 0, but not t = 0 itself. There is no evidence for time prior to the Big Bang, since time is just another coordinate in this Universe (depending on your Cosmological model), and the Universe did not exist prior to the Big Bang. In this model, time stretches back indefinitely, since it has no boundary, and there is no Big Bang; just that the way we measure it, we compress all t epsilon into a tiny tiny time, possibly artificially. Unless it makes a quantifiable prediction that allows it to be falsified, it is as useless as what we have now. Why do you waste time positing another "model" that cannot be falsified? I wasn't aware of that non-falsifiability, if indeed the idea is non-falsifiable. I also want to make people think. There's something physically abhorrent about an infinite energy density, which is surely more abhorrent, more complicated, than time being topologically open. In this latter model, then, the universe has been expanding forever, and the way the cosmos now looks, will carry on expanding forever. Oh, so you do make a prediction that is easily falsified. Infinite Universe has a "lack of iron and overabundance of hydrogen" problem. Entropy has not been seen to reverse in a macroscopic scale in the 13+ billion years displayed. Yet stars continue to manufacture heavier and heavier elements, use up their hydrogen "explode" and die. Where is your iron? Sorry, I'm not well enough up on the subject to see how the first part of your paragraph is related to the rest. David A. Smith -- Alan Mackenzie (Nuremberg, Germany). |
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Did there exist time t = 0?
Dear Alan Mackenzie:
On Feb 28, 11:30*am, Alan Mackenzie wrote: dlzc wrote: Dear Alan Mackenzie: On Feb 28, 9:27?am, Alan Mackenzie wrote: ... It's commonly asserted that the universe began at time t = 0 with the Big Bang. ?Is there any evidence for this existence of time t = 0? There is no evidence for time before about 270,000 years after the Big Bang. Then there is no evidence for the Big Bang itself; a steadily expanding universe fits the evidence just as well, does it not? No. There is no physics that is visible "this side" of the quench of the CMBR medium, that would permit that. In fact, distant objects are "anomalously" larger that today's, since they sourced their light into a smaller Universe. Extrapolation back an additional 270,000 years, based on the 13+ billion we have shown is a small step. "Infinite" is a good bit further. An alternative is that there exists time t for all t 0, but not t = 0 itself. There is no evidence for time prior to the Big Bang, since time is just another coordinate in this Universe (depending on your Cosmological model), and the Universe did not exist prior to the Big Bang. In this model, time stretches back indefinitely, since it has no boundary, and there is no Big Bang; just that the way we measure it, we compress all t epsilon into a tiny tiny time, possibly artificially. Unless it makes a quantifiable prediction that allows it to be falsified, it is as useless as what we have now. *Why do you waste time positing another "model" that cannot be falsified? I wasn't aware of that non-falsifiability, if indeed the idea is non-falsifiable. *I also want to make people think. You cannot make them think of your own idea, when you've spent no effort learning the billion or so cosmologies that are already out there, some of which are "superficially" like your own. *There's something physically abhorrent about an infinite energy density, which is surely more abhorrent, more complicated, than time being topologically open. These are your personal choices. In a small Universe, there is as much matter to the left as to the right. There is nothing to keep you small... Personally, I hold the CMBR to be the entire history of light that entered the black hole that is our Universe, from our container Universe. The horizon, if small enough, shreds all heavier elements to protons, electrons and neutrons. But then we aren't discussing my problem either... In this latter model, then, the universe has been expanding forever, and the way the cosmos now looks, will carry on expanding forever. Oh, so you do make a prediction that is easily falsified. *Infinite Universe has a "lack of iron and overabundance of hydrogen" problem. Entropy has not been seen to reverse in a macroscopic scale in the 13+ billion years displayed. *Yet stars continue to manufacture heavier and heavier elements, use up their hydrogen "explode" and die. *Where is your iron? Sorry, I'm not well enough up on the subject to see how the first part of your paragraph is related to the rest. Then how are you going to *make* people think, if you are not interested enough in cosmology to know what else is out there? http://www.astro.ucla.edu/~wright/cosmology_faq.html http://www.astro.ucla.edu/~wright/cosmology_faq.html#RB http://www.astro.ucla.edu/~wright/cosmo_03.htm David A. Smith David A. Smith |
#5
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Did there exist time t = 0?
"dlzc" wrote in message ... Dear Alan Mackenzie: On Feb 28, 11:30 am, Alan Mackenzie wrote: dlzc wrote: Dear Alan Mackenzie: On Feb 28, 9:27?am, Alan Mackenzie wrote: ... It's commonly asserted that the universe began at time t = 0 with the Big Bang. ?Is there any evidence for this existence of time t = 0? There is no evidence for time before about 270,000 years after the Big Bang. Then there is no evidence for the Big Bang itself; a steadily expanding universe fits the evidence just as well, does it not? No. There is no physics that is visible "this side" of the quench of the CMBR medium, that would permit that. In fact, distant objects are "anomalously" larger that today's, since they sourced their light into a smaller Universe. Extrapolation back an additional 270,000 years, based on the 13+ billion we have shown is a small step. "Infinite" is a good bit further. An alternative is that there exists time t for all t 0, but not t = 0 itself. There is no evidence for time prior to the Big Bang, since time is just another coordinate in this Universe (depending on your Cosmological model), and the Universe did not exist prior to the Big Bang. In this model, time stretches back indefinitely, since it has no boundary, and there is no Big Bang; just that the way we measure it, we compress all t epsilon into a tiny tiny time, possibly artificially. Unless it makes a quantifiable prediction that allows it to be falsified, it is as useless as what we have now. Why do you waste time positing another "model" that cannot be falsified? I wasn't aware of that non-falsifiability, if indeed the idea is non-falsifiable. I also want to make people think. You cannot make them think of your own idea, when you've spent no effort learning the billion or so cosmologies that are already out there, some of which are "superficially" like your own. There's something physically abhorrent about an infinite energy density, which is surely more abhorrent, more complicated, than time being topologically open. These are your personal choices. In a small Universe, there is as much matter to the left as to the right. There is nothing to keep you small... Personally, I hold the CMBR to be the entire history of light that entered the black hole that is our Universe, from our container Universe. The horizon, if small enough, shreds all heavier elements to protons, electrons and neutrons. But then we aren't discussing my problem either... In this latter model, then, the universe has been expanding forever, and the way the cosmos now looks, will carry on expanding forever. Oh, so you do make a prediction that is easily falsified. Infinite Universe has a "lack of iron and overabundance of hydrogen" problem. Entropy has not been seen to reverse in a macroscopic scale in the 13+ billion years displayed. Yet stars continue to manufacture heavier and heavier elements, use up their hydrogen "explode" and die. Where is your iron? Sorry, I'm not well enough up on the subject to see how the first part of your paragraph is related to the rest. Then how are you going to *make* people think, if you are not interested enough in cosmology to know what else is out there? http://www.astro.ucla.edu/~wright/cosmology_faq.html http://www.astro.ucla.edu/~wright/cosmology_faq.html#RB http://www.astro.ucla.edu/~wright/cosmo_03.htm David A. Smith Take it to religion.cosmo, Smiffy. This is sci.astro. David A. Smith Take it to religion.cosmo, Smiffy. This is sci.astro. |
#6
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Did there exist time t = 0?
Alan Mackenzie wrote:
Hi, SA, It's commonly asserted that the universe began at time t = 0 with the Big Bang. Is there any evidence for this existence of time t = 0? The easy answer is that we don't have evidence to determine the existence of time before the Big Bang. Similarly, we also don't have any evidence for the existence of space before the BB either. However, to get a little speculative, it's possible that the universe existed before the BB, and that the universe was already infinite, long before the BB. The universe may have existed as an infinite void, where there was neither a direction of time nor a direction in space. Inside the void, time neither flowed backwards or forwards, and events (fluctuations) simply happened randomly. One such random event resulted in the universe that we see now. Our universe is still part of the infinite void, but it's moving in only one direction in the time dimension. The void itself remains *on average* flowing neither forwards or backwards, so that means that if our universe fluctuated out of it in one direction of time, then that means some other universe was created that has time flowing the opposite direction. The inhabitants of that universe don't consider that their time is flowing backwards, then think it's flowing forward. Yousuf Khan |
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