2 ms·

https://en.m.wikipedia.org/wiki/Planck_time https://en.m.wikipedia.org/wiki/Planck_time https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(time) https://en.m

https://en.m.wikipedia.org/wiki/Planck_time https://en.m.wikipedia.org/wiki/Planck_time https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(time) https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(time)

raattgift 8y ago
Even though your two-link reply seems like an obvious "I don't want to talk any more", I'll leave you with three things. Firstly, there is nothing special about natural units compared to any other system of units, except that some popular formulae can take on especially simple forms in that system of units, provided one takes care not to lose dimensionality: https://en.wikipedia.org/wiki/Dimensional_analysis https://en.wikipedia.org/wiki/Dimensional_analysis You (still) are confusing two different dimensions, length and time. Again, this matters in a spacetime like ours, where the difference in dimensionality gives us a system of causality[1] and a reasonable setting in which to do time-series physics[2]. It also matters when switching from natural units to a different system of units in which c != 1, such that we cannot omit the conversion constant (or change of sign when calculating spacetime intervals [3]). Changing a physical system like a black hole from one system of units to another does not change the physics of the system, just how we describe them. It is enlightening to do so in general, because it is easy to fall into the trap of treating as physical a condition that vanishes upon switching to a different set of units. A quantity that is a ratio of two dimensionful quantities (area and information) surviving across changes of units on one or both dimensions may be interesting. In the case of black hole complementarity, which earlier you found links for, it's a (near-horizon) density that (according to some string theorists) corresponds directly with a (interior) density (states / volume) taking into account the Ricci tensor's effect on interior volume but removing the physical singularity through string interactions in a "fuzzball" or something similar[4]. Secondly, your second link says of Planck time, "Presumed to be the shortest theoretically measurable time interval (but not necessarily the shortest increment of time - see quantum gravity)", which does not really support your position. Rather than reinvent the wheel for you in qualifying that, which I think would be wasteful given your previous few replies, I'll direct you to physics se and in particular to Lubos Motl's 85 point comment at : https://physics.stackexchange.com/questions/9720/does-the-planck-scale-imply-that-spacetime-is-discrete https://physics.stackexchange.com/questions/9720/does-the-pl... Finally, I don't know what you're trying to accomplish although it seems you're set on convincing yourself and perhaps some people who know even less physics than you do that you know what you're talking about. Hopefully it's more optimistic and instead you're trying to learn more than you already do and are just going about it inefficiently. - -- [1] https://en.wikipedia.org/wiki/Causal_structure https://en.wikipedia.org/wiki/Causal_structure [2] https://arxiv.org/abs/1505.01403 https://arxiv.org/abs/1505.01403 (section 4) - sadly the wikipedia has only scattershot coverage of it in e.g. the short and/or not very accessible pages on the ADM and BSSM formalisms, and on Canonical Quantum Gravity (which is a quantization of the Hamiltonian formulation that is "only" an effective field theory good to one loop, and provokes the question of "the problem of time"). Unfortunately most introductory material about 3+1 formalisms in general is already highly technical (e.g., textbooks aimed at graduate students). [3] https://en.wikipedia.org/wiki/Metric_signature https://en.wikipedia.org/wiki/Metric_signature [4] https://www.wikiwand.com/en/Fuzzball_(string_theory) https://www.wikiwand.com/en/Fuzzball_(string_theory)

raattgift 8y ago

Even though your two-link reply seems like an obvious "I don't want to talk any more", I'll leave you with three things. Firstly, there is nothing special about natural units compared to any other system of units, except that some popular formulae can take on especially simple forms in that system of units, provided one takes care not to lose dimensionality: https://en.wikipedia.org/wiki/Dimensional_analysis https://en.wikipedia.org/wiki/Dimensional_analysis You (still) are confusing two different dimensions, length and time. Again, this matters in a spacetime like ours, where the difference in dimensionality gives us a system of causality[1] and a reasonable setting in which to do time-series physics[2]. It also matters when switching from natural units to a different system of units in which c != 1, such that we cannot omit the conversion constant (or change of sign when calculating spacetime intervals [3]). Changing a physical system like a black hole from one system of units to another does not change the physics of the system, just how we describe them. It is enlightening to do so in general, because it is easy to fall into the trap of treating as physical a condition that vanishes upon switching to a different set of units. A quantity that is a ratio of two dimensionful quantities (area and information) surviving across changes of units on one or both dimensions may be interesting. In the case of black hole complementarity, which earlier you found links for, it's a (near-horizon) density that (according to some string theorists) corresponds directly with a (interior) density (states / volume) taking into account the Ricci tensor's effect on interior volume but removing the physical singularity through string interactions in a "fuzzball" or something similar[4]. Secondly, your second link says of Planck time, "Presumed to be the shortest theoretically measurable time interval (but not necessarily the shortest increment of time - see quantum gravity)", which does not really support your position. Rather than reinvent the wheel for you in qualifying that, which I think would be wasteful given your previous few replies, I'll direct you to physics se and in particular to Lubos Motl's 85 point comment at : https://physics.stackexchange.com/questions/9720/does-the-planck-scale-imply-that-spacetime-is-discrete https://physics.stackexchange.com/questions/9720/does-the-pl... Finally, I don't know what you're trying to accomplish although it seems you're set on convincing yourself and perhaps some people who know even less physics than you do that you know what you're talking about. Hopefully it's more optimistic and instead you're trying to learn more than you already do and are just going about it inefficiently. - -- [1] https://en.wikipedia.org/wiki/Causal_structure https://en.wikipedia.org/wiki/Causal_structure [2] https://arxiv.org/abs/1505.01403 https://arxiv.org/abs/1505.01403 (section 4) - sadly the wikipedia has only scattershot coverage of it in e.g. the short and/or not very accessible pages on the ADM and BSSM formalisms, and on Canonical Quantum Gravity (which is a quantization of the Hamiltonian formulation that is "only" an effective field theory good to one loop, and provokes the question of "the problem of time"). Unfortunately most introductory material about 3+1 formalisms in general is already highly technical (e.g., textbooks aimed at graduate students). [3] https://en.wikipedia.org/wiki/Metric_signature https://en.wikipedia.org/wiki/Metric_signature [4] https://www.wikiwand.com/en/Fuzzball_(string_theory) https://www.wikiwand.com/en/Fuzzball_(string_theory)