Problems with synchronization and simultaneity in the inertial frame:

A few assumed details:

A pulse of light travels about a foot per nanosecond.
Distances do not change between stations in the inertial frame.
The rate of passage of time does not vary in the inertial frame.

Diagram of scenario:

A(white) 1000'Red 1000'Green 1000'Blue 1000'Yellow 1000' B(white)


Scenario:
Stations are placed every thousand feet along a straight line. The duration of the travel of light between stations is 1,000 nanoseconds. At each station, a slaved light pulse system only pulses on the detection of a white light pulse. The response latency of each slave pulser is five nanoseconds. Each slave responds with a different color of light. At each end of the line is a white light pulser, labeled “A” and “B,” respectively. The colors are ordered from A: red, green, blue, yellow. Located at stations “A” and “B” are video cameras capable of recording all of the flashes over the entire distance. (Five thousand feet)

When "A" pulses a white light once; the camera there will record red, green, blue, yellow, and white pulses at 1005 nanosecond intervals successively. The camera at B will record the white, red, green blue and yellow pulses all flash at once. When the white pulse at "B" flashes, the camera at B will record (in reverse order) yellow, blue, green, red, and white pulses at 1005 nanosecond intervals successively. The camera at "A" will record, after a lapse of 5005 nanoseconds, the white flash at "B.” Interestingly, all the color pulses will appear simultaneously with the white flash from "B,” on the “A”recording.

When the recordings are replayed, the "A" camera will show a series of successive flashes of color at 1005 nanosecond intervals. When the white flash from "B" appears, simultaneously with it, all the other colors flash. The "B" camera will show all the colors flash simultaneously, with the white flash from "A.” Then, in reverse order, at 1005 nanosecond intervals, the (yellow, blue, green, red, and white) colors will flash successively.

Add to the scenario: two clocks at each station, initially set to random time settings, but regulated to the exact same passage of time. Each station has one clock that will set its time to a light pulse from "A" and one that sets to a pulse from "B.” When pulsed, each and every clock will set its time to the exact same setting. For example: when each clock receives a pulse it will set to 6:00:00:00:00 (out to the nanosecond) O’clock. This system will synchronize the “A” clocks with the “A” pulse and the “B” clocks with the “B” pulse.
The pulse from A will set all the “A" sensitive” clocks from "A" to "B" successively to the above stated setting. The pulse from "A" will cause "B" to pulse 5 nanoseconds after it senses A’s pulse. B’s pulse will set all the clocks sensitive to B’s pulse to the above stated setting (successively as B’s pulse reaches each clock.) Comparing the clocks at each station, we find that each pair of clocks has an increasing difference in the time setting from "B" to "A.” the clocks at "B" have only a five nanosecond difference. The clocks at "A" are five thousand and five nanoseconds different.

Here is the strange thing: all the "A" sensitive clocks appear to have the exact same time when viewed from "B,” All the "B" sensitive clocks appear to have the exact same time when viewed from "A.” If the “A” clock from one station is exchanged with the “A”clock from another station after being set, their times will no longer appear to be synchronized with the other unmoved clocks when viewed from "B.”

Will a “flash of light” “synchronize” clocks at various distances? The above exercise demonstrates that this is not so.
From this exercise, we see that “simultaneity” or “synchronization” is a chimera; even when things are not changing distance. A pulse of light can appear to synchronize other pulsers, or even clocks, however the synchronization is only good from one point of view. Spank me if I am wrong.

Curt Youngs

One more important piece of information is needed.

Does light, in this experiment, travel in perfect vacuum?

To AAF:
My understanding is that there is no perfect vacuum within our galaxy. I suppose the assumption here is that light travels about a foot in a nanosecond. Makes the arithmetic easy. One thing for sure, it goes as fast as it does.
Did I miss something? A camera recording from along a line normal to "A" "B," at the mid point, about a mile away, will not record any of the pulses to be "simultaneous" with any other.(in the order of nanoseconds.)What say you?

After giving your question some additional thought, additional assumptions should be mentioned. The speed and direction of light radiation obviously depend on the density of the atmosphere. Atmospheric density depends on several factors. Temperature variations along the path refract the path, affecting the actual distance traveled by the light. Variations in gravitational acceleration affect the density also. Particulate matter in the air has an effect too. Distances and times have to be very exact to realize the small measurements.

At the present state of the art, surveyors use some form or system utilizing electronics to measure distance, as opposed to a steel tape, such as electronic distance measuring or global positioning system. Measuring time is also a problem, since, as I understand, it would be hard to find ten clocks with the accuracy required. Finding fifteen detection systems with identical latency would be a challenge, let alone the stated five-nanosecond response. Signal rise time and duration of the pulses is important. The curvature of the earth and orientation of the “line” might be important.

Therefore, the experiment, in actuality, woud at the least be very expensive. My point is: Seeing all the pulses at the same time, being the definition of simultaneous, is only observable at a special position in the “inertial frame,” with all points of interest at rest with each other. I remember that you said the transformation formulas already consider this, however, I have never had this explained regarding the inertial frame. How is the special position taken into account, and does it really constitute “simultaneous?”

Time may pass at a different rate of passage of time “locally,” never the less, there must be a galactic at the least or universal rate where the situation can be considered in each progressive instant. Time may be continuous or discrete. However, it seems to me that cameras, still, or motion, can capture the panorama from different distances and then be matched up after the fact – time wise as well as distance wise. I maintain that time is three-dimensional just like space.

Simultaneous seems to require at least two events and an observer or recording device. Then, the distance of the events from the observer must be known to determine “real simultaneity” Whether relations change slowly or quickly across the universe, everything does happen at the same “Time.” Because distance delays the arrival of radiation to any point, all the events surrounding that point, are effectively in the “past” relative to the point. Depending on the actual distance to the Sun, and the actual speed of light from there to us, what we see there moment to moment happened eight minutes ago.

Hi Curt;


Since, in refractive media,
the speed of light depends on frequency & color, light used in this experiment must be
monochromatic and of one color only.

This could be relevant to the topic under discussion:
http://casa.colorado.edu/~ajsh/sr/simultaneous.html

To AAF:

I suppose the experiment can be done with lasers, aligned on offsets parallel with each other, so that the pulse from each station can be distinguished from the others, and firing in opposite directions at the same time. Another signal from each station wold have to be aimed at the point normal to the line to prove that assertion.

Since space is not a perfect vacuum, does light refract there also? I think the "bending of light" by gravity is done indirectly by the atmosphere of planets or stars, rather than directly by gravity accelerating radiation itself.

Once the details are worked out, do you see what I see as to simultaneity, or more precisely, the mere appearance thereof, being observed only at "downwind" of "A"'s pulse in the first stage, and "downwind or "downpulse" of "B" in the second stage?

At this point the colors denote the stations between "A" and "B," rather then actual colors.

I am waiting for you, since I have your attention, and which I appreciate, to fault my main point.

All the best, Curt

To Stanley 16:

Yes, the site you provide is quite interesting. I have an easier time visualizing time on the same three coordinates as space, rather than on a fourth coordinate perpendicular to the initial three, an impossibility. Distance results in time delay, and the changing time delay of more or less linear motion causes the impossibility of of observing simultaneity between frames because the equal distance requirement of two events and the observer is broken unless the observer is traveling on a path normal bisecting the two events. Additional events must be on a circle on a plane through the two points and also normal to the above stated path of the observer.

My studies lead me to doubt the existence of black holes, dark matter and BIG BANG spin offs. There is too much evidence to the contrary. The Photos and overlays of radio, infra red, and x ray wave length photos in Halton Arp's catalog demand explanation. "Hubble redshift means distance" is dead. Most of the highly red shifted objects are obviously directly connected with objects (galaxies) having conventional nonshifted light.

Thanks for the attention, and do you see the problem here that I see. Can you fault my scenario?
All the best, Curt

To AAF:

Actually, the Electronic Distance Measuring parts of a total station could be used for the experiment: Retro-reflecting prisms facing both ways at each station and at "B" would suffice. The detector portion would act as the clock and sensors, two at each station. A periscope setup at each station would perform the same job as 360 degree flash at each station in the forward direction. Detectors at "A" and "B" would compare the arrival times. At each station the two opposite facing detectors would show the time difference there.

However, the results seem obvious to me. What say you?

Okay, Curt; let's get down to the 'meat & potato'!


Concerning simultaneity and the nature of time in general, here is the most basic question:


Do you think this moment we call 'NOW' is universal and the same everywhere in the Universe?


Or do you believe as Einsteinians do that there is no universal NOW and that simultaneity is relative and dependent on motion, gravitation, etc.?

To AAF:

You ask: “Concerning simultaneity and the nature of time in general, here is the most basic question: Do you think this moment we call 'NOW' is universal and the same everywhere in the Universe? Or, do you believe as Einsteinians do, that there is no universal NOW and that simultaneity is relative and dependent on motion, gravitation, etc.?”

Yes, I think this moment we call 'NOW' is universal and the same everywhere in the Universe.

Simultaneity has two faces: the simultaneity of all current events everywhere, regardless of distance or motion, and the observation of simultaneity. The former just happens, it is reality. The later depends on the equal distance from the observer to the events. Motion will cause an observer to lose the preferred equal distance required for “simultaneous” event viewing. Radiation traveling toward the observer brings the illusion that all events along the line being seen at an instant are “simultaneous” with each other, even though we know the further events happened further in the past. (Radiation traveling away from an observer cannot be sensed without other aids, i.e. a mirror or some such.)

I sell an automated cross slope system that is installed on road graders and other earth moving machinery. One of the accessories is a “Tri Sonic Sensor.” This devise sends signals to the hydraulic system to control the grading blade automatically, and form dirt to the required cross section. The sonic head will sense a string line, the edge of a curb, or follow the contour of a previously graded pass.

That said, when setting the characteristics for the head to perform to the way the operator likes to work, he has a choice whether the head will set its parameters “Absolute” or “Relative.” So, what do these terms mean? When set to “Absolute” the head measures the absolute distance from the string or surface to the sensor. When the “Zero” button is pressed, the distance from the string or surface becomes the “target” to which the grader blade will move as the pitch and attitude of the machine moves over unfinished ground. From time to time, the head will move closer or more distant from the reference. The system then powers the hydraulics to move the blade back to the “target” distance.

Setting the program to perform in “Relative” mode causes the distance meter to read Zero when the “Zero” button is pressed. This Zero distance is the same as the “Absolute” distance, provided the head is still the same distance from the surface or string. This distance is still the target distance, but the actual distance is now shown as “Zero.” Most operators prefer “relative” since if need be they can “move” the target setting up a “tenth” or what ever above “Zero” or minus (say, down a quarter tenth). If that setting is better, the meter can be rest to “Zero” for the new depth of “Cut.” Or Fill

The latest cosmic evidence reveals the Universe to be much smaller, and “relatively” at rest with itself. There may be some background, or ancient galaxy affirmed as being at rest, and from which every change in distance can be measured. In the mean time, we are stuck selecting a point in time and space, locally as the target or starting point for time and space measurement.

An aside: Walter Babin has done some very interesting research along these lines, (concerning time and the units of distance) which reveal relationships in the physical world, not suspected by the conventionally taught way of thinking.

Anyway, there are many conventions for measuring “time.” “Sidereal,” “Universal,” “Solar,” Lunar” “Jovian,” etc. Meat and potatoes / gravy, Yes, there is an universal regulation of time. This is not to say that locally the passage of time may run faster or slower, (or just appear to) but this would be caused by the density or the gravity of the particular place. (My “unpeered” theory of gravity is gravity does not “bend” radiation. I visualize radiation in straight radial lines from the source. The effective acceleration of gravity opposite the direction of radiation may affect the speed of the radiation, or simply remove the kinetic energy from it. Nevertheless, the radiation keeps going “straight"

I may lose you from my thoughts above. The “universal” time I contemplate is that events everywhere, even those in motion, even the radiation traveling every which way, can be “stopped” by photograph or video, (in all the range of frequencies) and studied frame by frame, matched by aligning reference points, across the solar system, galaxy, and universe. (Reality keeps on going regardless) There probably are effects that cross the vast distances faster than the “speed of Light.” The speed of light may have already been proven to depend on the speed of the radiating object. The fact remains, that our senses depend on radiation that has been measured to have a finite speed, and this causes all observers to exist in their own unique present, while their surroundings fade further and further into the past as the distance increases to the events sensed by the observer. (Not to be confused with the fading into the past caused by changing events) While we observe events now that have taken place long ago, I for one have no trouble expecting additional events happening there, right now, that I will undoubtedly never sense, yet are part of reality. In comments I have posted at http://www.wbabin.net/comments/youngs.pdf> I point out that dilation and contraction seem to me caused by considering motion without considering the time delays accompanying the distances. I believe the Doppler shift causes “time” to seem to pass faster in approaching distance change and alternately to seem to run slower in receding changes. These appearances are on the same order as the appearance of “simultaneity” in the inertial frame written about above.

By the way, what you and I “believe,” has no effect on reality, other than if we understand reality, we can probably use it to our benefit. I think both you and I are more concerned as to what is real than who is right. Agree? Objective observation, logic, compiling evidence, a learned, yet open mind, and a willingness to consider objections and criticism are required. Some body’s “off beat” idea will take us further toward understanding. Those who think nearly everything is already observed and understood have no idea how far they are from reality. I appreciate those of you who point out what I do not know or over looked in my thinking.

Rate this. Profound, or waste of band width.
All the best Curt

To AAF:

How do you get away with posting such short questions, and cause me to expound such long remarks?

All the best to you, Curt

My question is which "simultaneity" are we discussing? Reality, as the present advances, or as "time marches on," or observed "simultaneity" which is observing events which have already happened? A telescope looks further into the past, a microscope viewing live movements is looking closer to the present than the naked eye.

Hello Curt;


We have to discuss all of them; since all sorts of simultaneity are related in one way or another.

Obviously, simultaneity has two main sides, the logical side & the empirical side:

[1] The logical part of simultaneity:

As you pointed out, this part involves the simultaneity of all current events everywhere. From the standpoint of formal logic as well as classical mechanics, all events occurring at this very moment and everywhere in the Universe are simultaneous and must be simultaneous regardless of distance, motion, gravity, observational procedures, etc. That is on one hand. On the other hand, according to the theory of Relativity, events can't be simultaneous everywhere, because the flow of time, in this theory, depends on motion and gravitation. Only events in the one and the same frame of reference are allowed by this theory to go simultaneous and to occur at the same moment.


[2] The observational part of simultaneity:

This is where your planned experiment must apply. And if I understand you correctly, the experimental test, here, is whether or not the assertion of Einstein that two or more events in the same frame of reference can occur simultaneously is valid. And this means that you doubt even this small piece of simultaneity that Einstein had left for the enjoyment of his followers; right?

TO AAF:

Each of us exists in a sea of light radiation, rays bouncing every which way. As we move around, the scene changes. Everywhere we look, we see the “rays” of light traveling straight from objects to us. We might realize that other rays are bouncing off at other angles, but we never see them unless we change position. Then we lose sight of the original rays. We probably do not think about the distant rays coming toward us, gathering additional rays of more recent events along the way. When our brains present the scene to us, what we see, we think happened “simultaneously.” Some of us have seen an explosion or some other visual event, and then heard the sound follow a short time later. Few stop to realize the visual event was delayed also. It should surprise no one that eight minutes elapse for an event on the Sun to be observed on Earth. Why then should they be surprised that “simultaneous” with an event here on Earth, something happened on the Sun, which we will observe in eight minutes? Likewise for the crispy observer on the Sun, seeing an event on Earth that synchronizes with his eight minute ago event.

The point of the above paragraph (in case you missed it) is that things go on without us. If a man says something in a forest, and there is no woman there to here him, is he still wrong? However if there is no “simultaneity of all current events everywhere” what would there be? Someone said that time keeps everything from happening all at once. Well, I would say it is the principle that different objects cannot occupy the same place at the same time. In other words, it is distance (and the speed of light) that keeps everything from seeming to happen all at once. Because actually everything does happen, all at the same time.

The confusion is that radiation can occupy the same place at the same time. Thus, the radiation from more distant (and earlier in time) events arrives at our eyes at the same time with closer in distance and time events. We see all these events at the “same time,” “simultaneously,” yet the truth is they are not simultaneous.

A special point of observation is available, (the center of a sphere) upon the surface of which, all events seen at the same time occur at the same time. All post event, true simultaneity, rather, the observation thereof, must be equidistant from said events.

As I hopefully pointed out to Stanley 16: “Distance results in time delay, and the changing time delay of more or less linear motion causes the impossibility of observing simultaneity between frames because the equal distance requirement of two events and the observer is broken unless the observer is traveling on a path normal to and bisecting the two events. (for two events the observer’s line could be in a plane bisecting the two event points.) Additional events must be on a circle on a plane through the two points and also normal to the above stated path of the observer.” ) Which limits the observer to a line.)

Notice that in the inertial frame the observation point of simultaneity is the center of a sphere. Whereas, the moving observer is limited to traveling a line passing through the center, and perpendicular to the plane of a “simultaneity of all current events everywhere” circle. The events on the circumference of which will actually have been “simultaneous” as seen by the observer.

I think the hard part of understanding this, (I think I do), is that for instance, the events on the surface of the sphere that are observed to be “simultaneous” at the center, are not necessarily seen as simultaneous with each other. There seems to be a paradox here. One can become disoriented by trying to combine the “simultaneity of all current events everywhere” with the after the fact observation of “simultaneous” events.

The “simultaneity of all current events everywhere” is slewed at each point of observation by the finite speed of light and distance. If the speed of light were infinite, we would have no perception of time or distance. Every thing would indeed be seem to“happen at the same time.” I wonder if distant objects would appear smaller in such a world. I suppose they would.

I love Stanley 16, I can hardly wait his response.

All the best to you and Stanley, Curt

To AAF:
Well, I suppose you didn't make the accusation. Anyway, Things aren't the way they used to be. (and they never were.) I can't take something from those who never had it in the first place. No one should be upset.

Curt

AAF, I suppose Anonymous would have trouble following our discussion here?

AAF: "This is where your planned experiment must apply. And if I understand you correctly, the experimental test, here, is whether or not the assertion of Einstein that two or more events in the same frame of reference can occur simultaneously is valid. And this means that you doubt even this small piece of simultaneity that Einstein had left for the enjoyment of his followers; right?"


Curt: That is right, AAF, as to the observation of the events. Making the events all happen at the same time is simply to delay all the activating signals wherever, to the delay of the most distant place, from the control center.