Oct 17, 2014 03:15 PM
TRANSCRIPT SOURCE WAS ONCE HERE: http://members.fortunecity.com/templarser/flowtime.html
Roger Penrose : I think there's always something paradoxical about the way we seem to perceive time to pass and the way physics describes time.
Roger Penrose : Space-time is certainly different stuff from space because its 4 dimensional instead of 3-D (RP larfs!) which is a big diff. Time really has to be brought into the picture; this one thing which is space/time.
Physicist : Just imagine what this might be like: 3-D space implies a volume, and you can move any where in that volume. Once you add time as a 4th dimension, another axis, then this block of space/time would contain within it past, present and future, all at once. Time is frozen, all times exist together; so just as you can say "over here, over there" in 3-D space, you can talk about "over then", in 4-D space/time.
Roger Penrose : It's a way of looking at things if you like which physically we seem to be forced into. I say physically from the point of view of what the theory of rel. tells us. And Relativity is remarkably well tested, I mean, 14 places of decimal, it's just incredible. So we know that this theory does describe the universe to an extraordinarily precise degree, so we have to take it seriously. And that theory tells us that we have to regard space and time as one thing, it's all out there, it's one thing. In the same sense that space is out there, time is out there.
Narrator : Like the Medieval God's-view of time, Einstein's physics says that the future is already out there. The moments of our lives are just waiting for us to step into them.
Roger Penrose : But there's no more problem about the future being out there than saying that space is out there. You say, "Mars is out there", but why is that more comprehensible than saying "next week is out there"? It's just as far away in a certain sense.
Physicist : If you take this block of 4-D space/time literally, it means you have to abandon free will. It means not only is the future pre-ordained, but its already there, its already happened. There's no point in making any decisions, whatever you do has already happened. If I choose to drop this stone into a pond, I think of it being my own free choice, but of course in 4-D space/time I had no choice in dropping the stone ; the splash is already there in the future and so we lose all free will. If time travel was possible, you can imagine people coming back from the future to visit us; its no good us saying, "you cant exist - you haven't happened yet". They've come from a time which they consider to be their 'now' and for them we're in their path.
Roger Penrose : So this means that in a sense, the present past and future are out there, and that also gives us a very deterministic view of the world. We have no control of what happens in the future because its all laid out. I think the trouble that people have with this idea is that you think the future is under your control, to some degree, and so this means that if the future's laid out then in a sense its not under your control.
Physicist : Personally I'm very uncomfortable about the block universe idea. Now this may be just a gut feeling or just irrational, but can't accept the future's already 'out there'. I don't accept that I don't have any free will.
Roger Penrose : I think there is a positive side to this picture of space and time being laid out there as 4 dimensions, because it tells you that all times are there once and it can affect the way one thinks about people who have died. I mean, I remember thinking in this kind of way when my mother died. In some sense she was still there because her existence is still out there in space/time although in our time she is not alive. A colleague of mine had a son who died in tragic circumstances and I presented this idea to him and it helped his understanding also. This was before I heard that Einstein had a colleague died and he wrote to the man's wife that Bessa was still out there, and that somehow this was reassuring. I certainly think this way often, that space/time is laid out and that things in the past and things in the future are out there still.
Narrator : But almost at the same time that Relativity was gaining universal acceptance a radically different picture of the universe was emerging.
Physicist : The way out if you don't want to accept the block universe idea is quantum mechanics. Now, Quantum Mechanics is the second great discovery of the 20th century physics and that states that the future isn't predetermined and preordained.
Narrator : Quantum Mechanics was born out of a series of experiments whose results even today have no satisfactory explanation. Relativity works at the large scale where it provides exact predictions as to what will happen next. But when physicists started looking down at the atomic and sub-atomic level, the familiar laws failed. At this level, there were no certainties, only probabilities. How can the future of the universe be already out there if the future of a single molecule is so utterly unpredictable?
Physicist : Before we look to see what the atom is doing, not only is there a gap in our knowledge, the atom itself has not decided what to do. It had an infinite number of choices to make, it will be doing all those choices all at once, and its only when we look to see what is happening do we force it to make a choice. In Quantum Mechanics the future is not determined, and so Quantum Mechanics in a sense rescues us and rescues free will.
Roger Penrose : In a sense you don't have the future laid out in Quantum Mechanics So Quantum Mechanics. is basically different in the way we look at it. You do have this indeterminacy about the future and a necessary feature of this is its incompatibility with Special Relativity. So we have these 2 great theories, both of which are extremely accurate, tell us something about how the world operates, something very insightful and profound and accurate, but they're incompatible with each other. So there's no doubt there's something missing here. How important it is to how we 'feel' the passage of time is I think very important.
Narrator: The tragedy of modern physics is that it explains so much of the objective universe but at the cost of what we subjectively feel; about our conscious free will and our feeling that time does flow.
Faun Flynn: I very much think there's a flow to time. If you consider what music would be like if there was no flow to time. You couldn't have music if you didn't have memory, or if you didn't have an expectation generated by that memory. You'd have an isolated note in the 'now'. Music unfolds in time in such a way that we have a memory of what we've heard, and this memory conditions to what we expect. This of course is something that everybody is familiar with, because if you hear ( 7 note scale played on piano) you have a very strong expectation that the next note will be (plays final octave note of scale) . Music is a distillation or a side-effect of that mental faculty we employ to perceive time, and things changing in time.
Roger Penrose : The question of the passage of time is something the scientists have rather set aside, and taking the view that its not really physics, it's a subjective issue; and subjective questions are not part of science. Now when you start talking about phenomena like one's own perception of the passage of time, then that is a subjective thing. And that's almost a taboo subject for science because it's subjective. The physical world at least according to Relativity, is out there, and there is no flow of time, it's just there; whereas our feeling (we have this feeling of the passage of time) are intimately connected to our perceptions.
Physicist : We have this subjective feeling, that time goes by, but physicists would argue this is just an illusion.
Roger Penrose : Yes I think physicists would agree that the feeling of time passing is simply an illusion, something that is not real. It has something to do with our perceptions.
Narrator : Illusion or not, our perceptions emerge somewhere between the cosmic scale of Relativity where the flow of time is frozen and the quantum scale, where flow descends to uncertainty. Our world is on a scale governed by a mixture of chance and necessity.
Roger Penrose : My view is that there is some large scale quantum activity going on in the brain. Physics does not say that Quantum Mechanics takes place in small areas, but also take place over larger areas. I think this has to do with the consciousness. I think we need a new way to look at time, not either Quantum Mechanics or Relativity.
Narrator : If Quantum Mechanics is taking place in the brain then the same randomness of outcome and unpredictability might explain our ability to make sometime random choices. Opening up the future to the possibility of change would provide the first step of restoring to physics the flow of time it currently denies.
Physicist : I don't think time flows, I feel that time flows, but I feel we can only understand this if we have a better understanding of how consciousness works. I think human consciousness probably has the secrets as to how and why we think of time as going by.
Roger Penrose : I don't think we have the tools, I don't think we have the physical picture to accommodate these things yet. We're not very close to it.
Roger Penrose : I think there's always something paradoxical about the way we seem to perceive time to pass and the way physics describes time.
Roger Penrose : Space-time is certainly different stuff from space because its 4 dimensional instead of 3-D (RP larfs!) which is a big diff. Time really has to be brought into the picture; this one thing which is space/time.
Physicist : Just imagine what this might be like: 3-D space implies a volume, and you can move any where in that volume. Once you add time as a 4th dimension, another axis, then this block of space/time would contain within it past, present and future, all at once. Time is frozen, all times exist together; so just as you can say "over here, over there" in 3-D space, you can talk about "over then", in 4-D space/time.
Roger Penrose : It's a way of looking at things if you like which physically we seem to be forced into. I say physically from the point of view of what the theory of rel. tells us. And Relativity is remarkably well tested, I mean, 14 places of decimal, it's just incredible. So we know that this theory does describe the universe to an extraordinarily precise degree, so we have to take it seriously. And that theory tells us that we have to regard space and time as one thing, it's all out there, it's one thing. In the same sense that space is out there, time is out there.
Narrator : Like the Medieval God's-view of time, Einstein's physics says that the future is already out there. The moments of our lives are just waiting for us to step into them.
Roger Penrose : But there's no more problem about the future being out there than saying that space is out there. You say, "Mars is out there", but why is that more comprehensible than saying "next week is out there"? It's just as far away in a certain sense.
Physicist : If you take this block of 4-D space/time literally, it means you have to abandon free will. It means not only is the future pre-ordained, but its already there, its already happened. There's no point in making any decisions, whatever you do has already happened. If I choose to drop this stone into a pond, I think of it being my own free choice, but of course in 4-D space/time I had no choice in dropping the stone ; the splash is already there in the future and so we lose all free will. If time travel was possible, you can imagine people coming back from the future to visit us; its no good us saying, "you cant exist - you haven't happened yet". They've come from a time which they consider to be their 'now' and for them we're in their path.
Roger Penrose : So this means that in a sense, the present past and future are out there, and that also gives us a very deterministic view of the world. We have no control of what happens in the future because its all laid out. I think the trouble that people have with this idea is that you think the future is under your control, to some degree, and so this means that if the future's laid out then in a sense its not under your control.
Physicist : Personally I'm very uncomfortable about the block universe idea. Now this may be just a gut feeling or just irrational, but can't accept the future's already 'out there'. I don't accept that I don't have any free will.
Roger Penrose : I think there is a positive side to this picture of space and time being laid out there as 4 dimensions, because it tells you that all times are there once and it can affect the way one thinks about people who have died. I mean, I remember thinking in this kind of way when my mother died. In some sense she was still there because her existence is still out there in space/time although in our time she is not alive. A colleague of mine had a son who died in tragic circumstances and I presented this idea to him and it helped his understanding also. This was before I heard that Einstein had a colleague died and he wrote to the man's wife that Bessa was still out there, and that somehow this was reassuring. I certainly think this way often, that space/time is laid out and that things in the past and things in the future are out there still.
Narrator : But almost at the same time that Relativity was gaining universal acceptance a radically different picture of the universe was emerging.
Physicist : The way out if you don't want to accept the block universe idea is quantum mechanics. Now, Quantum Mechanics is the second great discovery of the 20th century physics and that states that the future isn't predetermined and preordained.
Narrator : Quantum Mechanics was born out of a series of experiments whose results even today have no satisfactory explanation. Relativity works at the large scale where it provides exact predictions as to what will happen next. But when physicists started looking down at the atomic and sub-atomic level, the familiar laws failed. At this level, there were no certainties, only probabilities. How can the future of the universe be already out there if the future of a single molecule is so utterly unpredictable?
Physicist : Before we look to see what the atom is doing, not only is there a gap in our knowledge, the atom itself has not decided what to do. It had an infinite number of choices to make, it will be doing all those choices all at once, and its only when we look to see what is happening do we force it to make a choice. In Quantum Mechanics the future is not determined, and so Quantum Mechanics in a sense rescues us and rescues free will.
Roger Penrose : In a sense you don't have the future laid out in Quantum Mechanics So Quantum Mechanics. is basically different in the way we look at it. You do have this indeterminacy about the future and a necessary feature of this is its incompatibility with Special Relativity. So we have these 2 great theories, both of which are extremely accurate, tell us something about how the world operates, something very insightful and profound and accurate, but they're incompatible with each other. So there's no doubt there's something missing here. How important it is to how we 'feel' the passage of time is I think very important.
Narrator: The tragedy of modern physics is that it explains so much of the objective universe but at the cost of what we subjectively feel; about our conscious free will and our feeling that time does flow.
Faun Flynn: I very much think there's a flow to time. If you consider what music would be like if there was no flow to time. You couldn't have music if you didn't have memory, or if you didn't have an expectation generated by that memory. You'd have an isolated note in the 'now'. Music unfolds in time in such a way that we have a memory of what we've heard, and this memory conditions to what we expect. This of course is something that everybody is familiar with, because if you hear ( 7 note scale played on piano) you have a very strong expectation that the next note will be (plays final octave note of scale) . Music is a distillation or a side-effect of that mental faculty we employ to perceive time, and things changing in time.
Roger Penrose : The question of the passage of time is something the scientists have rather set aside, and taking the view that its not really physics, it's a subjective issue; and subjective questions are not part of science. Now when you start talking about phenomena like one's own perception of the passage of time, then that is a subjective thing. And that's almost a taboo subject for science because it's subjective. The physical world at least according to Relativity, is out there, and there is no flow of time, it's just there; whereas our feeling (we have this feeling of the passage of time) are intimately connected to our perceptions.
Physicist : We have this subjective feeling, that time goes by, but physicists would argue this is just an illusion.
Roger Penrose : Yes I think physicists would agree that the feeling of time passing is simply an illusion, something that is not real. It has something to do with our perceptions.
Narrator : Illusion or not, our perceptions emerge somewhere between the cosmic scale of Relativity where the flow of time is frozen and the quantum scale, where flow descends to uncertainty. Our world is on a scale governed by a mixture of chance and necessity.
Roger Penrose : My view is that there is some large scale quantum activity going on in the brain. Physics does not say that Quantum Mechanics takes place in small areas, but also take place over larger areas. I think this has to do with the consciousness. I think we need a new way to look at time, not either Quantum Mechanics or Relativity.
Narrator : If Quantum Mechanics is taking place in the brain then the same randomness of outcome and unpredictability might explain our ability to make sometime random choices. Opening up the future to the possibility of change would provide the first step of restoring to physics the flow of time it currently denies.
Physicist : I don't think time flows, I feel that time flows, but I feel we can only understand this if we have a better understanding of how consciousness works. I think human consciousness probably has the secrets as to how and why we think of time as going by.
Roger Penrose : I don't think we have the tools, I don't think we have the physical picture to accommodate these things yet. We're not very close to it.