James R is very knowledgeable about many aspects of science. Years ago the scientific non-sense percentage of posts was lower, and I had the self appointed title, of the "sheriff of nonsense" and mainly corrected posts. I took special delight when I could correct James. - Only 4 or 5 times in ~10 years; but now he does not post about science as much and has taken over my duties as Sheriff when he does. I think my science error* rate was slightly higher than James's was. Anyway, the percent of non-sense is so high now that I resigned as Sheriff of non-sense, too much work to try to correct it all. * I made one bigger than all of James's combined - I thought the E-field and B-field of an EM wave were 90 degress out of phase - that the collaping B-field made the rising E-field. I argued that so well that I persuaded a few to accept that POV. James never came close to making an error like that - only little things like the infinite number of terms Fourier series perfectly reproduce the function it was the analysis of. It does not if there is a step in the function at some point. (It makes a dot half way up the step.)
What the hell are you on about? I don't really give a stuff about your [1] and [2] in relation to Sean Carroll. The only thing I have quote Carroll as saying is that Time should be thought of as real. In fact I already answer your irrelevant and confusing post at 814 thus...... In all those links, all four support the notion of time being real and also that the laws of physics do not forbid it. AND THAT IS ALL i HAVE EVER CLAIMED!!!!!!!!! http://en.wikipedia.org/wiki/Entropy#Entropy_of_a_system http://en.wikipedia.org/wiki/Entropy Now let's be quite clear again. [1] We all agree that the reality or otherwise of time is not fully and convincingly decided. [2] Irrespective, I see the evidence as supporting the affirmative. [3] I also see the mainstream in general of that same view, and offer many of tashja's expert opinions, along with Smolin, Carroll, Sagan, Thorne and Hawking [4] I also see the entropy and the second law of thermodynamics and the arrow of time as supporting the affirmative... [5] I see the non absolute nature of space and time as supporting the affirmative. [5]Professor Barbour while disagreeing with my reasonings and opnions, openly admitted that I have Newton Minkowsky Einstein on my side, as well as a legitimate argument for my position. [6]The argument so far pushing the negative aspect, I see totally bogged down in philosophical claptrap and many red herrings and irrelevant analogies such as clocks, candles and what not.
Sorry Billy, I did not mean to suggest there are no moderators with knowledge of science, even physics. Just that moderation in the Physics & Math forum is more or less reduced to policing rules and behavior, rather than the nonsense.
There's hardly any policing of rules and behaviour. The behaviour of some is appalling. I cringe when I think of tashja emailing physics professionals referring to some thread drowned out by howling sneering abuse. Billy: I wish you were the moderator here. And I also wish that somebody would do something about the abusive ad-hominem trolls who seek to spoil every decent discussion we have, and who never contribute in any positive way. OnlyMe: I refer to Einstein and the evidence. Or Maxwell and Minkowski and so on. What I tell you does not belong in alternative theories. The popscience nonsense you believe in belongs in alternative theories.
A whole page of posts seems to be missing. I wanted to edit one I recently made and saw it posted, but now it is gone. It was a reply to post of Paddoboy which is now also "gone"
True. The speed of light in a vacuum is your clock. In vacuum, the light sphere has a specific radius at every point in time, as measured in meters, given the calculated meters per second of the speed of light in vacuum. Leaving it at that, then time is measured by the speed of light, and time is variable when there is relative motion between objects, as long as the convention is to make the speed of light the constant in all frames. The variable time is quantified by Special Relativity, and the equations work perfectly, given the invariant speed of light in vacua. I'm just saying that there are mechanics in the nature of the universe that govern the "how" of the observable, time dilation. When responding to the OP, "What is time?", I took the approach that the how of time dilation requires a mechanistic explanation, and discussed the hypothesis of gravitational wave energy density of the medium of space as a possible solution. Generally accepted science has yet to establish a consensus on the mechanics, but threads like this establish the opinion that there is more to time than the mathematics of spacetime explains.
The speed of light in vacuum is not a clock, it is 299,792,458 m/s. The only way you know the radius is by knowing the time. The time is not negotiable. By definition, the meter is defined as the length of the path that light travels in a vacuum in 1/299,792,458 of a second. So 238/299792458 of a second means light traveled 238 meters. Not negotiable. Rock solid fact! There is no variable time, there is time. Time elapses and two different cars, or trains, or baseballs travel from location to location during a specific amount of time (not variable time). In one second a light sphere can increase its radius 299,792,458 meters, a baseball can travel .2 meters, a shaft can rotate 29 times, and I can take a nap. The second was the same for all, but each object did its own thing during that second. There is no "variable" second like you claim. That's nonsense!
Some things are more than one thing. The speed of light in a vacuum is a clock, and it is ~300,000,000 m/s. How is that not a clock? You just used it to measure the meter, and you measured distance in meters. Variable time is observable.
Speed of light is 299,792, 458 m/s. Clocks measure time, not distance per second. I can sit on a bar stool for 3 minutes, but light can't stay at one location for 3 minutes. See the difference now between a clock and the speed of light? You probably have a clock somewhere close by. Do you call that the speed of light, or a clock? I've seen it advertised as a clock, never the speed of light. Just sayin' It is a speed. Is your speedometer in your car a clock? How many minutes do you drive when you are driving 60 MPH? The locations are measured because they are part of a 3D grid of distance and time. Once there is an object and light in that 3D grid there are things that must be true and things that can not be true. So when 2 different objects are traveling in the grid, with a light sphere, there is time and there is distance. When we know distance and time in the grid there must be true and false things. You are trying to wiggle in false things into a true only zone. I can't allow that to happen. Please Register or Log in to view the hidden image! How is it determined to be different than non variable time?
OK, you do have a true only zone going for you, while I am opining that there is more to the local environment than the parameters of your "true only" zone. Now if you want to come out and play, then you have to consider my zone, and it is fraught with complexity. Please Register or Log in to view the hidden image!
Farsight, in a mathematical equation t is variable, its value is unassigned. A second has a fixed meaning based on the observer's frame of reference. Only in your imagination can you measure the duration of a second in any frame of reference other than the one you occupy. The fact that measurements made in different frames of reference don't agree and are explained as time dilation, is not a proof that the second has anything other than a single meaning. BTW it is that same variable t mentioned in the first sentence that makes GR dynamic and changing. You can wrongly, as you do, assume that t always has a fixed value, and space-time is a frozen slice of reality, but the truth is that it is variable and thus imparts to space-time and GR a dynamic and changing character. Sadly it does take, some imagination and a bit more understanding of the math, to comprehend the added dynamic aspect, the variable t provides. You seem to have been repeating telling yourself the same thing for so long, that you have lost the intelectual flexibility to see your own mistake(s).
Are you alluding to some "hidden" mechanics within GR that makes it dynamic an changing, or it is just your imagination that convinces you that those dynamics are real, instead of there being any mechanics necessary?
It's my way or the highway... Please Register or Log in to view the hidden image! ------------------------------------------------------------------------------------------------------------------------------------------------- Please Register or Log in to view the hidden image! ------------------------------------------------------------------------------------------------------------------------------------------------- Please Register or Log in to view the hidden image! ------------------------------------------------------------------------------------------------------------------------------------------------- Please Register or Log in to view the hidden image! ------------------------------------------------------------------------------------------------------------------------------------------------- Please Register or Log in to view the hidden image!
Now there's a sci-fi angle worth developing. Dr. Who catches up with his hijacked Tardis after synchronizing his sonic screwdriver to 2.99 picowicks, taken from a standard beeswax candle kept in a vault at the Vatican (after high fiving the Pope for acknowledging the Big Bang). Although I don't know the background I would argue that something went wrong in the analysis if the infinite series did what you just said. This idea seems to hinge on a philosophical argument over the meaning of convergence after computing the nth term. It's useful to speak of the spectrum of a step (square wave) and its derivative (impulse) and the proofs showing them to work as seen in a table of Fourier transforms and their inverses. Also see http://www.thefouriertransform.com http://mathworld.wolfram.com/FourierSeriesSquareWave.html
The good doctor in question retired from physics upon receiving a PhD. So he was never a professional. By contrast several professionals who took the program you never bothered to take have pretty solidly nailed your rhetorical treatment of physics to the wall, as usual. The behavioral issue, then, turns on the question of pretending to be able to intelligently discuss a scholarly topic without bothering to do the work, then crying when experts correct your nonsense and errors. As a pretext for quote mining, without having a clue what he is talking about. Flatly untrue. You run from evidence, which is why, to this day, you cannot describe the empirical results that motivated Einstein to publish his conclusions about relativity in 1905. Nor did you ever bother to learn the mathematical language of either of them. So you think rhetoric trumps evidence. Technically true since alternative theories are held to be correct by a minority of experts. Instead you belong in the cesspool. Until they create a forum for Dunning Kruger cranks. Said the poster who cannot pass a first week quiz in freshman physics, nor the qualifying exams to even enroll.
By "step" I was referring to a discontinuity. - Sort of obvious as I said the Fourier transform would have a dot at the mid point, but I could had said: "The FT of a function which is no where multivalued (as is the square wave at it edges) and discontinuous is not perfect. That "dot" has a name but I forget it so may not be able to search to show you the transform of this function which will have two dots. One at (0,1) and the other at (1,1). Here is the function: y = 2 for x positive but less than or equal to 1 and y = 0 otherwise. Even the multivalued (at edges) square wave is not perfectly reproduced. There is always a small "over shoot." This is Gibb's Effect ( or phenomena ) seen below: Please Register or Log in to view the hidden image!
Your post above quoted two separate issues as one. A second, is a second, is a second, is the answer to the first, if there was a first! The last line you quoted, in as dumbed down as it can be put.., since space-time includes time which is, in its simplest mathematical form designated as t.., a variable, the fact that t varies, is what defines the dynamics. If Farsight were right and space-time represented only a single slice or fixed instant, it could not describe gravitation.., because graviation includes change in the relationship of gravitationally associated objects. This whole discussion has drifted away from the OP, which asked what is time? That question has implications beyond the use of clocks in relativity or any of physics for that matter. Many of those who maintain that time is REAL, seem to do so from the believe that if some undefinable fundamental TIME did not exist, change could not happen. That is a philosphical debate. It runs into a chicken or egg question. The other side.., or the way I see it is that that fundamental question/answer is beyond our ability to test and verify. We are stuck comparring rates of change.., using clocks to measure change? So, again I say time is real in the same way that for us, awareness, consciousness, dreams and ideas are real. The same way that numbers and symbols are real. They are things whose meanings we can imagine and/or experience, that have no physical substance. But change happens in a read and physical, testable and measurable way.., the yard stick of course being our clocks... Or in a far less accurate manner our awareness of change. Back to what I think you were implying, because I do tend to run on and get distracted... How objects interact gravitationally is dynamic.., it changes... Things are not fixed and static. Space-time and GR are our best tools at present to describe the dynamics of those interactions. That is all I was saying in that last quoted line.... Still I do believe gravitation does have an underlying fundamental kinetic origin, yet to be understood. And I don't believe the modern interpretation of GR that suggests that the curvature of space-time causes gravitation... From where I sit today, GR and space-time is just our best descriptive tool/model for describing the dynamics involved. How things happen as a result of gravitation. This is way far from the OP even from much of the relevant side discussion(s) and should be thread of its own, that I am not prepared to start.
Thank you for taking the time to post that. I will spend some time on it; off hand it is reminiscent of the relativity of simultaneity. But then it looks like you apply the "true only" zone to it. Can't wait to get into it.
When responding to the OP, "What is time?", I took the approach that the "how" of time dilation requires a mechanistic explanation, and discussed the hypothesis of "gravitational wave energy density of the medium of space" as a possible solution. I'm just saying that there are mechanics in the nature of the universe that govern the "how" of the observable of time dilation. Generally accepted science has yet to establish a consensus on the mechanics, but threads like this establish the opinion that there is more to time than the mathematics of spacetime explains; a view which I see you might agree with. I think the recent discussion is in line with the OP. No need to start a new thread when the discussion is on-topic, and I'm not making the discussion about the alternatives, just that there are possible mechanics to explain time dilation.
