How do we define time? Based on the changes we can notice? If everything does not change, can I say time does not exist or stalled?
My premise is that there is a universal time that is the same everywhere, but because the rate at which all clocks measure time is variable relative to the local wave energy density, the local measuring of time says nothing about the rate that time passes universally. Under that premise, time would not "stall" and there wouldn't be a place (or time) that could exist without change. Universal time would be the rate that time would pass on all clocks if there was no local fluctuation in the wave energy density of space, i.e. from the consensus model, if time dilation did not occur. We could determine the rate that universal time passes if we knew the average universal wave energy density, which in the current consensus model would be equivalent to knowing the vacuum energy density of space, i.e. Einstein's cosmological constant. Because we can't get to the heart of the matter of universal time, the current consensus is that time dilates relative to the motion of inertial reference frames, and it is left at that. My model is motivated by the search for a mechanistic explanation for time dilation, as well as for gravity, and other aspects of natural law, and that has lead me to the gravitational wave energy density hypothesis.
Note that gravitational time dilation is said to be infinite at the black hole event horizon. So at that location time would "stall".
Certainly you can hold that POV, but it is a violation of Newton's first rule of philosophy (his version of Ockham's law.) as every thing (quantum or classical) that observably occurs in the universe can be described without any reference to time. I showed this in post 28 (and in post 184, showed that QM events are no exception, just a little more complex to eliminate any reference to time from then as each of probabilistic possible results much be separately considered.) As post 28 is a long way back, and only a formal general proof of how time references can be eliminated, I give one simple example here: The height of a burning candle, h(t) is normally given by the simple equation like: h(t) = H - Bt, where H is the original length, B is the burn rate, and t is the time lapse since the candle was lit. The units of t might be hours, those of H be inches, and B is inches per hour. B (and all rates), sort of have time "hidden" in them so lets start by expressing B in more basic terms: B = K(Op)/r^2 where The "K" is a different constant depending up what the candle is made of (paraffin or bee's wax etc.) and it also depends on the unit used (feet vs. inches, hours vs. minutes, etc.).The "Op" is the partial pressure of oxygen. (It is exothermic chemical reaction of O2 with the vapor of the wax, not time, that makes a candle burn) I.e. B is "linear" in Op so any given candle will burn less brightly but longer in "mile high" Denver than in NYC. The "r" is the radius of the candle. The inverse r^2 just reflects how much wax is available in each inch of candle to make combustible vapor as it gets hot. Thus, as equation 1a, in conventional time explicit terms: h(t) = H - {K(Op)/ r^2}t. Every thing in Eq. 1a except time is a real observable, but time has no properties that can be observed, so we can convert Eq.(1a) into Eq(1b) which is: t = (H - h) / {K(Op)/ r^2} in hours for K so chosen. Now all terms on the right side can be observed , measured. One can certainly claim that the t on the left side is measured by this "candle clock" and in fact "standard candles" were* used as clocks 100 or so years ago. Now lets consider an asteroid in circular orbit about the sun, but closer than Earth is: Kepler (and Newton) told us that the cube of the semi major axis was proportional to the square of period. We can get the proportionality constant, k, in hours from Earth's nearly circular orbit: (1AU)^3 = k(365.25x24)^2 or k = 1/(8766)^2. Now the cube root of 4 is about 1.6- So if I assume that the asteroid is (1/1.6-)AU from the sun, the cube of that is 1/4 and that equals to y^2, where y is the "asteroid's year, y. With the assumed distance from the sun, y = 0.5 of an Earth year or y = 4383 hours. Thus as equation (2a), explicitly using time, as Eq. (1a) did, for the fraction its orbit, f, the asteroid moves thur in time t is: f = t/4383. Or if we want to use the asteroid as a clock as we did the candle, we have Eq. (2b) t = 4383f hours. The problem is that BY THEMSELFS, Eq(1a) and Eq. (2a) are TOTALLY USELESS, as time, t, in these equations is not observable as the height of the burning candle or the location of the asteroid in its orbit are. The ONLY thing we can do is eliminate the unobservable time from both equations and express the asteroid's progress f in terms of the candle's height, h. I.e. what we MUST DO is combine the two useless equations in to one, using the "timeless" right sides of Eq. (1b) & Eq.(2b) by noting that: t = (H - h) / {K(Op)/ r^2} AND that t = 4383f So as two things being equal to the same thing, they are equal or (H - h) / {K(Op)/ r^2} = 4383f. Now the progress of the asteroid in its orbit is given by (only in terms of observables) as: f = (H - h) / {K(Op)/ r^2} /4383. SUMMARY: It is not just that we always can eliminate any reference to unobservable time ("Not Sensible" is what Newton said about his "absolute mathematical time" parameter, t, in his equations.) in a COMLETE description of all events (motions) in the universe; It is in fact what we ALWAYS DO! (as time does not exist as a detectable observable.- It may exist, like angels may, but assuming it (or angels) do is a violation of Ockham's Law and Newton's first principle of proper philosophy.) That is: We ALWAYS select something with motion and call it a "clock" then relate all other motions (or chemical reactions rates, which are invisible atomic motions) to the movement of that chosen "clock." Currently the best thing to be selected as a clock is certain countable oscillations of Cesium atoms in an "atomic clock." (Just as side note, where I worked for 30 years, APL/JHU we had an atomic clock, one of seven 7, as I recall, that NBS averaged to tell how time was officially advancing.) * I have been in Paris more than a dozen times. After the first few, there was little "touristically" I had not done so I went into public buildings as if I had business there**. One stop was an auction mainly of properties re-possesed for failure to have paid taxes but some not claimed lost items were being sold too***. The auctioneer used a unique candle clock. When there seemed to be no more bids from the audience, he lit a candle, that did not burn stably. It sometimes flared up and some times sputtered. Several times as it sputtered, and new slightly higher bid would be yelled out. When candle did go out - that property was sold to last highest bidder. Often the "sputtering candle" flared up instead of going out. - A much more fair system than: "Going, Going, Gone!" which the auctioneer can be slow to say, unless his friend has just made a higher bid. ** Some advice: Safest thing to do is go straight to the elevator and get off when no one else remains. - Hold the door open while making a quick glance around - get back on if anyone notices you. I ended up on the top floor of the Pasture Institute one day - no one there (It was lunch time.) It was a conference room with a big table that had two stacks of funding proposals on it. I read a few from the taller stack - presumably they were not going to get their requested grant. I toyed with the idea of making a switch - take one with same requested funding from the shorter stack, put it in the tall stack and move one asking for the same funding, conversely. Rationalizing that someone had to give "fait" a little help, but decided not to do that, so just enjoyed the view from one of the tallest buildings in SE Paris. *** One was nice bicycle. When it came up for bid and young teenage boy yelled out "6 Franks and 47 centimes." No one else bid although the bike was certainly worth ten times that. It did my heart good. If any one had, I was planning to make sure they "tripped" going down the stairs. As I said above, sometimes "fait" needs a "helping foot" well placed on the stairs. All in all it was one of the most interesting hours I ever spent in Paris and totally free.
I know. There is that misconception that time measured by clocks, when "stalled" by the extreme energy density of a black hole, means that time itself stops. In my view, the clock will stop functioning in that extreme energy density environment, but time will continue to pass.
Time, clocks and everything else, is never seen to stop at any EH. From any remote FoR, signals arriving will be continually red shifted until beyond viewing capabilities, but from the FoR of someone falling into the BH carrying a clock, nothing peculiar happens...no time dilation, no freezing of any kind. That is relativity.
Actually, if I understand correctly, even though your clock seems to be ticking off time at the same rate as the gravitational energy density increases when you approach a black hole, to a distant observer your clock will appear to be slowing, and when the energy density increases to the point that particles no longer function properly, that clock will appear to have stopped when viewed by the distant observer. He would also observe you being spaghettified, Please Register or Log in to view the hidden image!.
No, I'm pretty sure that's not what happens. The signal/light from the clock to any outside FoR is red shifted until completely fading from view and the viewing capabilities of your instruments.. No stopping of the clock, or freezing at the EH is ever seen. I have for the purpose of simplicity ignore tidal gravitational effects, [responsible for spaghettification] which anyway could be virtually non-existent if the BH was big enough.
Hi Quantum, i think it is very important that any theory we have can be seen to make sense at the most basic level. e.g. we would be foolish to write books about "gravity" if we could not pick up a rock, release it and see that it falls. So we must have at least one simple experiment that pretty much anyone can see is sound. the simplest idea of "time" is that it flows from a future to a past. so , logically, we should check that before we rush off into understanding black holes and time dilation etc. i.e make sure we dont take a wrong step as our first step. So, why not try an experiment to check our most basic of assumptions ? if time exists then this should be very clear from the outset... But, if there are problems with even the simplest experiment, then surely we need to check our most basic assumptions... No matter how many people, professional our otherwise assume they are sound... Where is their experimental proof? Please Register or Log in to view the hidden image! That may seem pretty naive, but if you are assuming there may be a thing called time, and your premise is "that there is a universal time that is the same everywhere,", what is your premise for assuming time in the first place? My point is that we tend to rush off into trying to decide if "time" is united or independent of space, and if "time" "from its own nature flows equably without regard to anything external", or if "time" can be dilated ... etc etc etc but this may be like arguing whether all "ghosts" are naturally scary, or only some ghosts are, or where ghosts come from, or what ghosts eat etc, thinking one answer may be closer to the truth, when in fact all questions about he nature of ghosts, or "time" may be completely invalid. And we may be starting from a bad premise - that we dont actually have a single scientific experiment, as per the scientific method to support. So I would ask, what is your most basic definition of time, and what experiment do you think could show evidence of it? mm (re 'time' dilation, this may just be change dilation. it seems there is an effect that does indeed slow the oscillators in gps satellites etc, but as Farsight and others suggest that may just be dilated motion, IE internal change , within the moving object. And not the dilation of a thing flowing into a past etc - unless we can come up with an experiment to show that is what is happening)
I remember a thought experiment where Einstein was riding in a carriage away from the town square, and looking at the clock behind him. He imagined that if he could speed the carriage up to the speed of light, it would appear to him from the carriage that the clock had stopped. We know that he could not speed the carriage up to the speed of light, but yet the point of the thought experiment was about the appearance of the clock back in the square from his relativistic carriage. That is what I am referring to when I say that a distant observer would see your clock slowing to a stop, while you had the perspecitve that your clock was functioning normally all throughout the acceleration; aside from spaghettification. As for the effect of gravity in my scenario, I am accounting for the acceleration of the clock entering the black hole as if it was caused by the gravitational wave energy density hypothesis I mentioned. Are you saying that you are considering the effect of curved spacetime on the acceleration of the clock into the EH, but that if you also considered the tidal effect the clock would be going faster as it entered the EH. How do you distinguish between the effect of the curvature and the tidal effect on the acceleration of you and your clock into the EH?
Hi mm, Back in post #225 I acknowledged all of the possibilities that you mentioned, and concluded that if those possibilities were true, our society would be a much different one. My premise in response to Saint is about gravitational wave energy density, and how it is hypothesized to affect the rate that clocks measure the passing of time, not that they are measuring time itself. It is an attempt at a mechanistic explanation of gravity, while GR is a mathematical quantification.
I don't refute Einstein's thought experiment. I'm just saying that an observer at a safe distance from a BH, will never actually see the clock as stopped. Just red shifted to infinity. The tidal effects are as far as I am aware, caused by the nature of the critical curvature of a BH. That's why one could enter a large enough BH, and not suffer spaghetification until he was well in towards the center. And in the case of a Kerr type spinning BH, if one entered the BH in line with the axis of spin, one can theoretically pass through its "ring singularity" equidistant from all parts of the ring, and tidal gravity effects would all be cancelled out.
Please read post 485 and comment. It is without opinion - just facts. We have ~450 page of opinion, some about BHs. Post 485 is simple example of post 28's point . It shows that not only is it possible to eliminated ANY mention of time when describing the entire universe, but that is IN FACT WHAT IS ALWAYS DONE.
The passage of time is just a figure of speech. Time doesn't pass like buses, or footballers. You must have seen a science-fiction movie where some guy has some gizmo that stops time? When he presses the button what it actually stops is motion. Apart from his own motion of course. What makes me laugh is that if the gizmo really did its job his motion would stop too, and that would be it. He could never press the button again to start time again.
If we eliminate time, there would be no dynamics in the universe. As a simple experiment, we can take a snap shot picture of an event. This will stop time at a single point in time. If we use a digital camera, the software will place a time stamp for that exact point in time where the event is stopped. What you will notice is all the stuff within the photo and the positioning of this stuff is still there. The colors and textures are also still there. However, nothing is happening in terms of motion or state changes. There is no dynamics with time stopped or factored out. Any equation that uses time, as one of its units, such as velocity, acceleration, etc., is not evident in the photo. This is because time has been eliminated from the photo. Something is missing in terms of fully describing the reality of the original event. Reality operates more like a movie, where time remains. The stuff of reality moves between quantum states, like the frames of a movie. The gap between each frame of the movie, is where time comes in, since each frame is a still picture that is stopped in time. Time is not in the quantum state itself but in the gap between. The gap does not show up in the still frames of the movie. The frames contain all the substance. The gap lack tangible reality, since there is no record of substance or distinct states within the gap. The gap nevertheless has a potential, and causes the transition between two points in time, with time stopped in each frame on opposite sides of the gap, with each frame having all the substance. The gap potential and transition mechanism is connected to an analogy of motion blur. Motion blur occurs when the speed of the action is faster than the shutter speed. The action is in gap. The frames for the quantum states are the shutter speed. Motion blur creates uncertainty within distance/space and reflects time/action being expressed within space, but with time stopped. The time potential in the gap, creates uncertainty in space, from which blurry transitions occur between tangible quantum states; transition blur. I prefer to express the gap transition as time potential being converted to distance potential to create change of state and position, through uncertainty transitions between quantum states. Those who factor out time, stick with only the substance within the frames, but ignore the gap since it lacks any known substance. This is valid in terms of sticking to tangible things. However, I find it useful to retain the gaps and time since distance potential to time potential transitions are also possible, where loss of discontinuity and uncertainty within position (frames) can create time potential, for branching transitions; entropy. The gap is not connected to finite or inertial reference associated with space-time but with the C reference, where space-time is broken down into separated threads of time and space. These can weave extra time and space into the fabric of space-time; embroidery.
No, if we eliminate motion there would be no dynamics in the universe. But motion is empirical. I can waggle my hands and show you motion. And I can point to the second hand of a clock and show you some more motion. It's there, it happens, I can't eliminate it. But whilst I can show it to you, you can't show me time.
I think the logic is good, and time, when considered a constant, can easily be replaced by some observable. I'd like to add that the distinction between time being variable as in GR, and time being a constant as it was used by Newton and Maxwell, was what lead him to the resulting variable time dilation in GR, as I recall from a Physicsforums thread. Over in the Physicsforums I read a tread where it was said that Einstein considered that Newtonian dynamics were the same in inertial frames, but that Maxwell's EM was not. In other words, he said Newton's gravity was invariant; Newton considered the speed of light as instantaneous, and time was not a variable. Einstein understood Maxwell's EM was not invariant, and the speed of light varied relative to the observers motion. He converted Maxwell's equations to make them invariant by making time and space relative, and thus Maxwell's laws could be made invariant in spacetime. In the case of two clocks in relative motion, he realized that you couldn't determine which clock was in fact moving, and this resulted in him defining time as "what is measured by a clock". This made time in different frames to be different, and out of that, time dilation emerged, as I understand it.
Farsight As long as there is virtual energy and associated fields in the vacuum, time never "stops" from the perspective of any inertial reference frame of which other matter is capable, simply because matter is moving in one of an infinitude of possible directions. The whole Milky Way is moving away from distant galaxies at relativistic speed. Time continues here for the same reason it would continue no matter how close to the relativistic speed limit we were traveling with respect to anything else. Time and inertia, as well as the limited rate of propagation of all energy / bound energy derives of the limited speed of light in the infinitude of inertial states of virtual unbound energy in the vacuum. Time is the only dimension that exists, and it exists only for energy, in a particular direction. The rest of the reality we perceive is only a superposition of this single dimension. I know that you already know this.
