Intoscience Posted July 6, 2021 Posted July 6, 2021 17 hours ago, iNow said: If the space is completely empty, what’s making the assertions about existence or doing the measuring? Well this is sort of the point, can something said to exist if it can't be measured, or experienced in someway? 16 hours ago, swansont said: Time most certainly be measured. How would you measure time in this situation then? The point I was trying to make was whether or not space-time is emergent from something more fundamental. Is it a state that emerges from the birth of existence (something measurable), or is it a fundamental underlining property to the laws of nature that govern our universe? I was listening to a talk from one of the leading theoretical physicists who's working at CERN and the LHC. (I will try to find a link to the talk) He mentions that there is a popular notion that many scientists believe that spacetime is "doomed". They know that if they probed deeper into smaller distances (Planck scales) of space and time using higher energies required, space time collapses to form tiny blackholes. I don't know the full details on why they assert that spacetime is doomed, but it appears that it has something to do with the fact that it cannot be measured below a certain limit.
swansont Posted July 6, 2021 Posted July 6, 2021 2 hours ago, Intoscience said: How would you measure time in this situation then? Personally I’d use atomic clocks. 2 hours ago, Intoscience said: The point I was trying to make was whether or not space-time is emergent from something more fundamental. Is it a state that emerges from the birth of existence (something measurable), or is it a fundamental underlining property to the laws of nature that govern our universe? I was listening to a talk from one of the leading theoretical physicists who's working at CERN and the LHC. (I will try to find a link to the talk) He mentions that there is a popular notion that many scientists believe that spacetime is "doomed". They know that if they probed deeper into smaller distances (Planck scales) of space and time using higher energies required, space time collapses to form tiny blackholes. I don't know the full details on why they assert that spacetime is doomed, but it appears that it has something to do with the fact that it cannot be measured below a certain limit. I imagine they were discussing the next level of theory, much like Newtonian physics was “doomed” by relativity, and yet, it works just fine in most everyday situations. It’s possible a concept of spacetime won’t work at the Planck scale.
Intoscience Posted July 6, 2021 Posted July 6, 2021 (edited) 1 hour ago, swansont said: Personally I’d use atomic clocks. I imagine they were discussing the next level of theory, much like Newtonian physics was “doomed” by relativity, and yet, it works just fine in most everyday situations. It’s possible a concept of spacetime won’t work at the Planck scale. I think we are at a mis-understanding, By empty space I'm talking about no existence of anything, no measuring device to do the measuring, in other words no motion, no temperature, no change. In fact, what does empty space mean when we consider there is no way to measure it? Roger Penrose describes such an idea in his cyclic model of the universe, whereby the universe "forgets" how big and old it is. AFAIK, The expansion of space continues to accelerate and rip all the matter and radiation apart to the point where all the fundamental particles become causally separate from each other thus making it impossible to measure the distance and time between them. In this state the universe has no way of measuring a definitive size or age, so "forgets" how big and old it is. Space-time becomes arbitrary, thus can randomly start again in another big bang. Its a wild idea and one I struggle to fully understand but, I get the basic concept. Regarding the "doomed" space-time, yes I agree and I believe this is the idea, that space-time like Newtonian physics, works just fine for the everyday general theories. I think they are aiming at the extremes. Edited July 6, 2021 by Intoscience
iNow Posted July 6, 2021 Posted July 6, 2021 1 minute ago, Intoscience said: By empty space I'm talking about no existence of anything, no measuring device to do the measuring, in other words no motion, no temperature, no change. This is a philosophy question, not science. You may as well be asking how time would respond if Harry Potter froze it with his wand.
swansont Posted July 6, 2021 Posted July 6, 2021 1 minute ago, Intoscience said: I think we are at a mis-understanding, By empty space I'm talking about no existence of anything, no measuring device to do the measuring, in other words no motion, no temperature, no change. You can't have completely empty space. Relativity tells us that physics acts the same in all inertial frames and in all places in those frames. This means if I measure time at one place, I know the passage of time in all points in my frame; it's the same. IOW, I don't need a clock at a particular location to know the time there, if I have sufficient knowledge of the conditions.
Intoscience Posted July 6, 2021 Posted July 6, 2021 1 minute ago, iNow said: This is a philosophy question, not science. You may as well be asking how time would respond if Harry Potter froze it with his wand. Maybe, but I did explain why I considered this concept based on Roger Penrose's cyclic universe hypothesis. 1 minute ago, swansont said: You can't have completely empty space. Relativity tells us that physics acts the same in all inertial frames and in all places in those frames. This means if I measure time at one place, I know the passage of time in all points in my frame; it's the same. IOW, I don't need a clock at a particular location to know the time there, if I have sufficient knowledge of the conditions. Again, you are mis-understanding my point. Maybe I'm not making myself very clear. I'm focusing on what time is, i.e the definition of time as a single concept. We know time exists if it can be measured in some way. But if it can't be measured, where there is nothing to measure it with (like in Penrose's idea) then does it exist anyway independently? In other words is time and also space (since they are entwined) a fundamental property or is it emergent from something else?
swansont Posted July 6, 2021 Posted July 6, 2021 48 minutes ago, Intoscience said: I'm focusing on what time is, i.e the definition of time as a single concept. We know time exists if it can be measured in some way. But if it can't be measured, where there is nothing to measure it with (like in Penrose's idea) then does it exist anyway independently? In other words is time and also space (since they are entwined) a fundamental property or is it emergent from something else? Seeing as this is posted in the relativity section, I am giving you answers according to relativity. Time is what we measure with a clock. When you posit conditions that are contrary to physical law, then physical law isn't going to be able to give you answers.
Intoscience Posted July 6, 2021 Posted July 6, 2021 (edited) 12 minutes ago, swansont said: Seeing as this is posted in the relativity section, I am giving you answers according to relativity. Time is what we measure with a clock. When you posit conditions that are contrary to physical law, then physical law isn't going to be able to give you answers. Contrary to physical law? I'm positing conditions that are at the extremes of our understanding and ideas from respected physicists who specialize in this field. Non of this is my own idea, I'm just pointing out that to understand if time exists then we may need to understand fundamentally what time is. Since it appears that relativity breaks down at the small extremes, where time may fundamentally emerge from, then maybe relativity is not the key to answering this question. Edited July 6, 2021 by Intoscience spelling 1
swansont Posted July 6, 2021 Posted July 6, 2021 31 minutes ago, Intoscience said: Contrary to physical law? I'm positing conditions that are at the extremes of our understanding and ideas from respected physicists who specialize in this field. Space with nothing in it isn't possible. Contemplating whether time is emergent from this notion is something that some scientists and/or philosophers pursue, but that doesn't mean the situation is physically realizable. i.e. it's a gedanken experiment, a thought problem, where one ignores the constraints of physics. Quote Non of this is my own idea, I'm just pointing out that to understand if time exists then we may need to understand fundamentally what time is. Since it appears that relativity breaks down at the small extremes, where time may fundamentally emerge from, then maybe relativity is not the key to answering this question. There's a whole bunch of physics we can and will do without understanding time's behavior or nature at the Planck scale. Time as an emergent phenomenon may not be a question of relativity. But, you posted this in relativity...
Intoscience Posted July 6, 2021 Posted July 6, 2021 Just now, swansont said: Space with nothing in it isn't possible. Contemplating whether time is emergent from this notion is something that some scientists and/or philosophers pursue, but that doesn't mean the situation is physically realizable. i.e. it's a gedanken experiment, a thought problem, where one ignores the constraints of physics. There's a whole bunch of physics we can and will do without understanding time's behavior or nature at the Planck scale. Time as an emergent phenomenon may not be a question of relativity. But, you posted this in relativity... I apologise, for posting this in the relativity thread (my bad) I shan't continue to add to this discussion further.
Phi for All Posted July 6, 2021 Posted July 6, 2021 1 hour ago, Intoscience said: In fact, what does empty space mean when we consider there is no way to measure it? Nothing. You've constrained the description until it no longer resembles anything physical. 3 hours ago, swansont said: Personally I’d use atomic clocks. It's ironic that you always know when to play the atomic clock card.
studiot Posted July 6, 2021 Posted July 6, 2021 1 hour ago, Intoscience said: I'm just pointing out that to understand if time exists then we may need to understand fundamentally what time is Yes that is a fair point +1, a pity you are too late to make it to the OP. The OP was rather rambling and ill defined. The only question (point) for discussion I can see is On 7/2/2021 at 10:19 AM, Heis3nberg said: But leaving out the loop quantum theory, Can we see the time? Which has already been answered. 1
swansont Posted July 6, 2021 Posted July 6, 2021 24 minutes ago, Intoscience said: I apologise, for posting this in the relativity thread (my bad) I shan't continue to add to this discussion further. I didn't mean for you to not pursue this. It's something that has merit, but it's not something existing physics is going to be able to answer. 7 minutes ago, Phi for All said: It's ironic that you always know when to play the atomic clock card. Precisely when. (and it's more hydrogeny, cesiumy and rubidiumy) 2
studiot Posted July 6, 2021 Posted July 6, 2021 23 minutes ago, Intoscience said: I apologise, for posting this in the relativity thread (my bad) I shan't continue to add to this discussion further. If you wish to discuss your offering there is nothing to stop you starting your own thread with a better OP 1
Intoscience Posted July 6, 2021 Posted July 6, 2021 (edited) 11 minutes ago, swansont said: I didn't mean for you to not pursue this. It's something that has merit, but it's not something existing physics is going to be able to answer. "I'm just pointing out that to understand if time exists then we may need to understand fundamentally what time is. Since it appears that relativity breaks down at the small extremes, where time may fundamentally emerge from, then maybe relativity is not the key to answering this question" I have nothing to add in terms of relativity. Relativity is consistent to our observations and predictions and is currently the best model of space-time we have. I just refer you to this (my quote) in one of my previous posts. Thanks 9 minutes ago, studiot said: If you wish to discuss your offering there is nothing to stop you starting your own thread with a better OP Thanks, I may start a thread on this topic since the talk I listened to was very interesting, when discussing the smaller distances and high energies of the LHC quantum probing experiments. I just have no expertise and have limited knowledge on the subject. Edited July 6, 2021 by Intoscience
Holmes Posted July 6, 2021 Posted July 6, 2021 16 hours ago, beecee said: We are able to measure the passage of time. The thread's title is about the existence of time, that's a profound question that must include perception. We do not measure the passage of time, we instead make two observations and then an inference is drawn that time has passed. The person seeing a wall clock who is then given a general anesthetic will, upon waking see that the two clock readings differ by seven hours yet they feel like just a moment apart. I am arguing that that perceived time is real, it exists and is observed by the individual, the calculated elapsed time differs from what they perceive. 16 hours ago, beecee said: Many things exist that we really don't or never experience. I have never been to China. Does that mean China does not exist? I don't know and neither does anyone else, there is no proof that anything exists other than self, cogito, ergo sum. 16 hours ago, beecee said: "Philosophy consists very largely of one philosopher arguing that all others are jackasses. He usually proves it, and I should add that he also usually proves that he is one himself." Henry Louis Mencken. I thought we were having a polite conversation, it seems not. 3 hours ago, iNow said: This is a philosophy question, not science. That's a philosophical claim not a scientific one.
swansont Posted July 6, 2021 Posted July 6, 2021 6 minutes ago, Holmes said: The thread's title is about the existence of time, that's a profound question that must include perception. No, it's formulated as a physics question, and asks about measuring time, which means we are excluding perception.
Phi for All Posted July 6, 2021 Posted July 6, 2021 1 hour ago, swansont said: Precisely when. (and it's more hydrogeny, cesiumy and rubidiumy) You're an atomic fountain of information! 6 minutes ago, Holmes said: The person seeing a wall clock who is then given a general anesthetic will, upon waking see that the two clock readings differ by seven hours yet they feel like just a moment apart. I am arguing that that perceived time is real, it exists and is observed by the individual, the calculated elapsed time differs from what they perceive. But in the case of the person under anasthesia, their perception is NOT real. What allows you to cherry pick one situation over another?
Holmes Posted July 6, 2021 Posted July 6, 2021 1 hour ago, Intoscience said: "I'm just pointing out that to understand if time exists then we may need to understand fundamentally what time is. Since it appears that relativity breaks down at the small extremes, where time may fundamentally emerge from, then maybe relativity is not the key to answering this question" I think you are raising important questions, questions that go to the core of what science is. Scientific explanations are always reductionist yet here we are with an irreducible thing we call "time", it seems time cannot be explained, cannot be decomposed. 1 hour ago, Intoscience said: I have nothing to add in terms of relativity. Relativity is consistent to our observations and predictions and is currently the best model of space-time we have. I just refer you to this (my quote) in one of my previous posts. Einstein reframed time into events, special relativity deals with events rather than directly dealing with time, a train passing my window that coincides with my clock showing 17:23:19 is an event to Einstein and the special theory of relativity is about how the things that comprise an event are perceived differently by different observers. This bring the subjective experiences of observers into play. 1 hour ago, Intoscience said: Thanks Thanks, I may start a thread on this topic since the talk I listened to was very interesting, when discussing the smaller distances and high energies of the LHC quantum probing experiments. I just have no expertise and have limited knowledge on the subject. 1 minute ago, swansont said: No, it's formulated as a physics question, and asks about measuring time, which means we are excluding perception. You cannot exclude perception though. You cannot propose arguments and explanations in science based on observations without factoring in an observer.
swansont Posted July 6, 2021 Posted July 6, 2021 2 minutes ago, Holmes said: Einstein reframed time into events, special relativity deals with events rather than directly dealing with time, And he did the same thing with distance. Quote a train passing my window that coincides with my clock showing 17:23:19 is an event to Einstein and the special theory of relativity is about how the things that comprise an event are perceived differently by different observers. It's not perception. The actual amount of time passing is different for observers in different frames.
Holmes Posted July 6, 2021 Posted July 6, 2021 2 minutes ago, Phi for All said: But in the case of the person under anesthesia, their perception is NOT real. What allows you to cherry pick one situation over another? It is you who just cherry picked, you just said one perception is not real yet another is!
swansont Posted July 6, 2021 Posted July 6, 2021 3 minutes ago, Holmes said: You cannot exclude perception though. You cannot propose arguments and explanations in science based on observations without factoring in an observer. Sure you can. If the stopwatch we are using says the duration of something is 3.00 seconds, there is no disagreement that the stopwatch says 3.00 seconds. We don't ask people how long they think the duration was. We remove perception from the problem.
Holmes Posted July 6, 2021 Posted July 6, 2021 2 minutes ago, swansont said: And he did the same thing with distance. Indeed he did. 2 minutes ago, swansont said: It's not perception. The actual amount of time passing is different for observers in different frames. Yes, observers in different Galilean frames perceive different intervals.
swansont Posted July 6, 2021 Posted July 6, 2021 1 minute ago, Holmes said: Indeed he did. Yes, observers in different Galilean frames perceive different intervals. Perceive undersells the situation for relativity. The time is actually different, regardless of perception. To use "perceive" suggests there is a true value underlying this for someone with perfect clarity to discern. The time difference is real. It's not an illusion.
Phi for All Posted July 6, 2021 Posted July 6, 2021 3 minutes ago, Holmes said: It is you who just cherry picked, you just said one perception is not real yet another is! My claim has evidence to back it up. The perception doesn't match natural observation and measurement. Your claim that this perception is real has only subjective confirmation.
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