phyti

1. Since the axis of simultaneity is skew symmetric for inertial motion, the observer has to synchronize his fore and aft clocks (using light signals), to maintain the appearance of a rest frame. 2. Because its's defined to be so, and there still is no known way to verify it. The observer cannot measure his speed relative to light (v/c), only his speed relative to another object.

I'll read the paper later. The comments in the abstract about the simultaneity convention are true.After developing the theory using relative light speed (c-v & c+v), from the perspective of an absolute rest frame(the only one where those terms apply), Einstein knows there is no way to measure the time of a remote event since it requires a local clock, thus he defines the out and back paths as equal. It works because the complementary phenomena of length contraction and time dilation results in equal round trip times. The dynamic duo also scales the xt relations, thus preserving light speed measurements.

The first part is a counter example to show acceleration is not a factor. The second part shows all moving clocks lose time, it's just a question of which one loses the most. twin clocks2.doc

I thought this was settled long ago! There are references online for experiments proving time dilation is not affected by acceleration. This is why the lorentz factor only contains a term for speed, v/c. The integral expression involving acceleration, used for a continuously changing or easily defined path, is only a mathematical convenience. Sometimes it's easier to integrate a volume of discrete masses by assuming a continuous medium, than summing a large number of particles.

Many do. Not being detectable is not equivalent to not existing. Where were all those 'fundamental' particles before they were 'discovered'? More convincing is developing the theory from a fixed frame, then transforming to relative values.

Light emission may be considered an absolute rest frame for two reasons. Events don't move, and light speed is an absolute value independent of all material motion. If it was not, there could not be a defined invariant interval between events. Light moves relative to the observer, just as any thing moves relative to another thing. It just can't be measured because of compensating phenomena. ajb any observer is at rest relative to himself any object is at rest relative to itself

Who was that masked man?

U=1-1+1-1+… (-1)*u+1=u 2u=1 u=1/2 The series oscillates between 0 and1, like a superposition of states, or like a tossed coin before it comes to rest. It has both values with an average, (contrary to the minds oversimplistic expectation that it should have one value). Find a good book on fuzzy logic, it may help.

In the simplest abstract case of the 'twin paradox', with instantaneous velocity changes, the change of paths for the traveling twin is the most obvious difference, and so becomes the solution to an asymmetrical case. The reality is this paper. twin clocks130518.doc

The earth distance= 7.5 ly. Speed =.6c. Expected travel time= 7.5/.6= 12.5 y. gamma =1.25. Time dilation for Pam = 12.5/1.25=10 y. Since her clock and her sense of time indicate 10y, she concludes the interval of 7.5 ly has contracted to 7.5/1.25= 6 ly. The paradox is based on a false assumption that each twin sees the others time dilation. They do not. What they see is relativistic doppler effects, because clocks are frequencies.That's why the effects are reciprocal, and depend on converging or diverging speeds.

In the simple 'twin pardox' triangle, where the twins (or clocks) separate, the one that returns has the least amount of accumulated time.

The moving observer is AFFECTED by time dilation, but so is his clock, and everything that moves with him. By using the capitalized word, I can say he does not experience it, nor detect it. The moving observer is AFFECTED by length contraction, but so is his ruler, and everything that moves with him. By using the capitalized word, I can say he does not experience it, nor detect it. Anyone NOT moving with him will observe the effects to varying degrees, depending on their relative motion. It's the observers own motion that causes the effects, not the motion of the rest of the universe.

Didymus Lets simplify the calculations with v/c = .8 and target 10 ly distant. A-naut Al blasts off from earth, accelerates in orbit to speed, and sets his clock to zero as he passes Ed on the earth setting his clock to zero. Al and Ed have never read anything pertaining to SR (they spend all their time conducting experiments in an underground bunker) They calculate time to target = 10/.8 = 12.5 yr. Later, as Al passes the target, he records his clock reading of 7.5 yr. He has arrived earlier than calculated. SR predicts as a result of the motion, Als ship and all its contents will function at a slower rate due to time dilation, and be length contracted, but Al will not be able to detect either of the effects. To reconcile the time difference, Al interprets his time dilation as a contraction of the universe outside his ship by a factor of 7.5/12.5 = (.6). The contraction of the ship is a physical phenomenon resulting from altered em fields. The contraction of the universe is perception, i.e. physical phenomenon confined to and conditioned by the mind. When the observer moves, no one else shares his experience unless they move with him. The supposed symmetry between moving objects is only true comparing motion in isolation. If examined within the context of all physical phenomena within the universe: 1. the momentum of the earth -Mv is not equal to the momentum of the ship mv, 2. the energy to move the ship would not move the earth, and 3. the pilot can control the ship at will, but not the earth. Hope this provides some clarity.

You say the light aquires the speed of the clock, and the vertical component adjusts to maintain constant speed of c. This would establish an angle for the light path at that specific speed. Now we make one alteration by moving the distant mirror closer by half the distance. The speed and angle remain the same. How does the light intercept the mirror?

Consider the light clock. We count the number of cycles for light moving a distance of 2d, d being the separation of the mirrors. Isn't this just comparing vt motion of an object with ct motion of light? The clock event t is used to correlate some event of interest for the purpose of ordering and recording for future reference. As for the person choosing between futures, they form their future by their choice according to current conditions.

I'm still looking for an explanation of how the vertical oscillation in the light clock aquires a horizontal speed component when the clock moves horizontally in order to work for an observer moving with the clock at any speed less than c.

If my understanding is correct, with light moving at c relative to the ether, the zigzag path was an incorrect assumption. I want to be sure before moving on.

Accepting length contraction as an explanation for equal transit times in x and y, and no ether influence, consider the light clock. Observer A sees/is aware the photon oscillates vertically between mirrors. If the clock moves horizontally relative to A, and the clock continues to work for B who moves with the clock, how does the light/photon aquire a horizontal speed component (the zigzag path)? The 1st postulate states that B should see the same result as A for all speeds less than c.

If a passenger in a static capsule points a laser vertically, it reflects from the ceiling vertically. If the capsule is moving at .5c, the laser is still supposed to reflect in the same manner per the 1st postulate of SR. The posts I've read say the beam moves at an angle to accomplish this, as viewed by a static observer. I've never seen an explanation as to what causes the angular deflection in terms of physics. As the op says, it is contrary to constant independent light speed, which has much experimental verification. The question: Is the angle of the beam (or single photon) dependent on speed?

The rear ball speed relative to the passenger is -.143, i.e. it's moving away.The ball can't catch up to the passenger! You must have been interrupted by the cat, or something. You usually have to the point responses, and great animations. If a passenger in a static capsule points a laser vertically, it reflects from the ceiling vertically.If the capsule is moving at .5c, the laser is still supposed to reflect in the same manner per the 1st postulate of SR. The posts I've read say the beam moves at an angle to accomplish this, as viewed by a static observer. I've never seen an explanation as to what causes the angular deflection in terms of physics. As the op says, it is contrary to constant independent light speed, which has much experimental verification.

Doubting my own interpretation, my question is the same as the op. If light speed is independent of the source, how does it aquire a horizontal v component when it's directed in a transverse/perpendicular direction?

You're right about inadequate labeling. Fig. 2 is built on fig. 1 with M and E in the same orientation. Ignoring B, the upper curve (red) plots the distance AE. Coming from the left horizon it's decreasing. As A gets closer to M, AE decreases at a faster rate. As A passes M (the minumum separation) the distance AE is not changing. As A continues on (the green curve), the distance AE increases in the reverse manner. The horizontal axis through E plots the speed of A at each x location, which also equals the slope of the upper curve. Following the upper curve left to right, it slopes downward, levels off to zero at M, then increases,forming a mirror image of the left side. This should help you see the correspondence of the upper curve to the lower curve.

As the green or red object passes M (at a constant speed), it's neither approaching nor receding from E, thus the closing speed of either relative to E is zero at that point. The closing speed varies because the path of the objects are offset from E. Closing speed for the objects relative to each other is constant because they are on a collision course.

I prefer 'altered perception' over 'magic' anytime. There should be no misinterpretation. In the hallucinogenic case there is nothing in the outside world corresponding to the mental images. In the a-naut case there is. No, it's not a trick, just physics. The a-nauts' perception of time and space are real to him. Why doesn't the moving a-naut not question his slower rate clock, because his slower rate mind can't detect any difference, thus you have 'proper time'. I raise this point because some people think only the clocks run slower. What else is there besides images in the mind? That's all you have through sensory input from the 'outside' world. As for optical illusions, are things 'really solid', is the moon 'really a sphere'? We use abstract images/concepts/notions to model the physical world. So it seems the illusion is in our mind and the corresponding reality is external.

It's altered perception. All processes that involve light propagation occur at a slower rate for moving objects, because light has one speed in space. This would include the mind. If you give someone a hallucinogen, the images in their mind are real, yet those who do not participate do not share the experience. His is not false, just different. Time doesn't pass. Events happen at different rates depending on your motion through space. I can set my clock to run fast or slow for a week, yet the number of sunsets remains the same, i.e., my clock is not relevant to events in the world, it's only a convenient tool to count and order those events. If everyone is moving, then all perception is 'real' or 'illusion'. The choice is whatever makes you feel secure.