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When a photon is released, which way does it head?


tar
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tar, no one has been disputing the fact that many directions can have great significance. You will note that the direction in your example is important to us because it is a direction whose axes points perilously close to us. It is a relative direction.

 

However, we are not talking about directions, we are talking about magnitudes of velocity and your initial claim that there was such a thing as an absolute velocity. Now, after scores of posts, you are still persisting in trying to salvage some sense that you were right. You were not and this should have been wrapped up days ago with a simple acknowledgement from yourself that you were mistaken.

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Ophiolite,

 

I thought I said, OK no absolute motion. I get it. But that does not wrap it up, because the thread is about which direction a photon goes in, when it is released from an atom.

 

My questions are a kind of thinking out loud. I, for myself, am not content with the idea that a photon can be here, then there, without having been all the places on some real route between the two spots. It happens mightly fast, but it happens.

 

But let me ask you a question. If you say there is no absolute velocity, what is C all about?

 

You can not have a speed unless you have a time in mind it took something to get from A to B.

 

Regards, TAR


If it took a second to get from A to B and a photon was the thing doing the getting, A and B are 186thousand miles apart, or at least there is a 186,000 mile route, one could map out to get the photon from A to B.

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Ophiolite,

 

I thought I said, OK no absolute motion.

At some point , in the midst of umpteen posts, I think you did, but you then went on - in post after post - to say "Yes, but...". You sounded very much like someone who did not really believe, or who was unwilling to publicly concede they were mistaken. Perhaps I am allowing my own ethos to creep in here. When I am mistaken I find it important to say so loudly, clearly and unequivocally and I react badly to anyone who appears to be doing so less than wholeheartedly. (This, as an aside, is an open invitation to anyone to point out to me any instance where I have not honoured that on this forum.)

 

 

My questions are a kind of thinking out loud.

It would have helped me had you made this clearer. Perhaps that's just me.

 

I, for myself, am not content with the idea that a photon can be here, then there, without having been all the places on some real route between the two spots. It happens mightly fast, but it happens.

I must be misreading a lot in this thread. Where is anyone making that claim?

 

But let me ask you a question. If you say there is no absolute velocity, what is C all about?

I don't understand. In what way is c an absolute velocity. (I presume you meant c and not C.)

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Ophiolite,

 

Publically, I get the logical issue of not being able to choose a reference point that is absolutely stationary, which all other items and motion can then be judged against.

 

But the truth, and reality, is not something that requires my OK. What is true will be true, quite independantly of my take, or my model of it.

 

My interest is to have, for myself, the most workable and fitting model of the place, that I can muster. If a thing makes no sense, and does not fit in the model I have constructed, and learned about, I look for the ways to adjust my model so that it does work.

 

In this is where my reservations about the finality of "no absolute motion" come in. It is why I float the possibilities of photons not knowing they are in the lab, and are instead moving in reference to the center of the galaxy or in reference to the great atractor, or in reference to the Sun, or the center of the Earth, or some combination of these realities, when it leaves an atom.

 

A photon might not know it is suppose to go in a straight line through the slit and to the screen. It might be off in a direction that would take it through the slit, but only because the slit moved into its path.

 

If the position of the great attractor, and the center of the galaxy, and the Sun and the orientation of the lab to these things makes a difference to the observed path of a photon, which it might, then one could only notice the obedience to these things, if one kept close track of the direction that these potential affectors were in, in reference to the experiment.

 

That is my drift here, or what I am trying to suggest. Not that absolute motion is determinable, but that our motion in reference to everything else we know about, is determinable. And for all possible situations we might find ourselves in, understanding our position and motion, within such an unbelieveably huge framework, is quite sufficient.

 

Regards, TAR


Yeah little c if that is what the conventional symbol for the speed of light, is. I made a mistake. And my ethos is just fine thanks.


If c is the speed limit of the universe, and no mass can travel faster than that, and photons travel at this speed, and one can define space and time based on this motion and say the time it takes this item to move 186000 miles is one second and the distance the item will move in one second is 186000 miles, then both time and space are defined by c and c defines both time and space.

 

How much more absolute, in terms of a velocitiy, do you wish to be presented with?

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If c is the speed limit of the universe, and no mass can travel faster than that, and photons travel at this speed, and one can define space and time based on this motion and say the time it takes this item to move 186000 miles is one second and the distance the item will move in one second is 186000 miles, then both time and space are defined by c and c defines both time and space.

 

Sorry, it doesn't work like that. Time and distance are observer dependent.

 

Imagine that you are here on Earth and Alice is in a spaceship travelling at 87% of the speed of light to her new home at Alpha Centauri. You will both agree on measurements of the speed of light, but you will think it is 4 light years (23 trillion miles) to her destination, but she will think the journey is half that distance.

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Yeah little c if that is what the conventional symbol for the speed of light, is. I made a mistake. And my ethos is just fine thanks.

Whoa there! I carefully said "When I am mistaken I find it important to say so loudly, clearly and unequivocally and I react badly to anyone who appears to be doing so less than wholeheartedly."

 

Note the emphasis on the appears in the original. I was not accusing you of being intellectually dishonest, I was stating rather plainly that you gave the appearance of such behaviour. That is annoying. If you do not wish your motivations to be questioned then do not post in a questionable manner.

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... When I am mistaken I find it important to say so loudly, clearly and unequivocally and I react badly to anyone who appears to be doing so less than wholeheartedly. (This, as an aside, is an open invitation to anyone to point out to me any instance where I have not honoured that on this forum.)

I can attest your grace in defeat. :)

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The closest we can come to an absolute frame is the CMB. We can easure our velocity with respect to the observable universe by the amount of blue shift in the direction we are heading and the red shift in the opposing side ( the direction and speed we come from ). The CMB is isotropic to 1 part in 10000, so the blue and red shift are readily evident.

This is still not an absolute frame as there is no such thing !

Edited by MigL
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Ophiolite,

 

If a fella does not get the joke, it would be intellectually dishonest to laugh, just because everybody else is laughing.

 

It has already be determined that there is no absolute frame of reference. SR is built on it. The twins measure distance differenly, it all makes perfect sense to someone who gets the equations and knows how to put time and distance as compatriots.

 

You know I am wrong, everybody else with a physics degree knows I am wrong, I am just not sure yet that I am wrong. Thus my half hearted statement that I am wrong. I accept that I am wrong, in that I am suggested a different way to look at the situation, than is accepted as the right way to look at it.

 

But I like my way better, and am liable to keep testing it, to see if its right.

 

My feeling is that it must be a certain distance from A to B. And what is currently happening at A and what is currently happening at B are separated by that distance, but everything that is happening is happening now, regardless of our ability to observe it happening, because of the distance between our eye and the event.

 

Strange,

 

You speak about the way the traveling twin will measure distance, as if its a certainty. Its a thought experiment. You might have it wrong. There might be realities that get in the way of the trip going off just as written up on paper. For instance the traveling twin might be boiled by the cosmic rays she is running into because of her speed. And if she was aware of the source of the electromagnetic frequencies she was running into, she might know what wavelength they started out as, and could figure how many she transgressed, and multiply out the distance that many wavelengths would have been spread out over, if taken as measured by the stay at home twin. So how do you know how she is going to figure her speed and the distance she has traveled?

 

Regards, TAR


If she knows her clock is going to run a certain way because of her speed, might she not just apply the correction to her figuring?


MigL,

 

The closest we can come to an absolute frame is the CBM?

 

What is wrong with using that? Its not like we are ever going to exist in a different universe. If this one is giving us a frame of reference, I think it would be appropriate to use it. So what if we have no way to call it absolute. Its close enough, considering it represents the farthest we can see. Who is going to ever come up with something more significantly orienting than that?

 

Regards, TAR

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Because it still isn't and will never be an absolute frame. Same as there's no universal 'now'.

 

Why not just say 'I know I'm wrong" as you have, and add 'I will try to learn from books and other's knowledge', instead of incessantly bringing up unrelated stuff like death by cosmic rays ( ?) and being so verbose.

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You speak about the way the traveling twin will measure distance, as if its a certainty.

 

Why do you think people are defending this idea so vehemently? It isn't just because it sounds fun, or because someone called Einstein suggested it.

 

It is about as certain as anything gets in science, it is so well tested. It also forms the basis of much other science and a lot of technology from the transistors in your computer to the Large Hadron Collider.

 

If you were correct you will have to explain why Maxwell's equations are wrong, come up with an alternative to quantum field theory. You will also have to explain why all the technology based on it continues to work and why we cannot detect the variable speed of light.

 

 

If she knows her clock is going to run a certain way because of her speed, might she not just apply the correction to her figuring?

 

Of course she can. And we do, regularly. But that doesn't change what is actually measured.

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MigL,

 

I like to figure things out on my own.

 

If someone in a book suggests that someone is traveling at a relativistic speed, lets say 9 tenths the speed of light, my instant assumption is that they are traveling 270,000 km per second. They have to be going that fast relative to something, or the statement is meaningless. They would have to be going that fast, relative to a something that was not going that fast.

 

In the twin paradox there are assumptions made as to what this twin would measure and what the other twin would measure, as per distance. I am not sure why, if there is no preferred frame of reference, why it is the traveling twin that is moving at 270,000 km per second, and why she is not stationary and the rest of the galaxy is moving at 270,000 km per hour in the other direction.

If you can take it either way, then clocks slowing down and speeding up and distances shortening because of motion does not make any sense, because the effects would cancel out, if it was all relative and there was no establishment that was created by the already setup arrangement of the planets around the Sun and the stars around the center of the Galaxy and the local cluster's movement around the great attractor, all in reference to the CMB.

 

So, for me, you are left with a timing difference, when things are very far away. That is why I suggest there is a universal now, where things are happening 13.8 billion years after the big bang.

 

If the traveling twin goes off, very fast in a certain direction, in a second she will get to a place that is almost a second away from us. Much like the Mars rover was 14 minutes from us. The Mars rover never left reality, and alway was in a portion the the universe that was exactly as old as every other portion. If the Mars rover would be returned to Earth, according to my theory, it would still be as old as the universe is, and would have never gotten any younger or older than the place.

 

How could it? It never left reality. Just took a different route through what was always now in the universal sense.

 

The question would be, how many instances of the Mars rover do you figure there are? I figure there is only one instance. Since it was 14 minuties away at one point, it existed in the universal now as only one instance of the Mars Rover, even though that instance took 14 minutes to be seen or sensed by someone or something here on Earth.

 

Regards, TAR

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In the twin paradox there are assumptions made as to what this twin would measure and what the other twin would measure, as per distance. I am not sure why, if there is no preferred frame of reference, why it is the traveling twin that is moving at 270,000 km per second, and why she is not stationary and the rest of the galaxy is moving at 270,000 km per hour in the other direction.

 

When the travelling twin is stationary or moving at a constant velocity, then what you say is correct. However, for some of the time she is accelerating. At that point the situation is no longer symmetrical because you can tell who accelerated and who didn't. (If you like, velocity is relative, but acceleration is absolute. Until you come to take gravity into account.)

 

And, of course, this has been tested experimentally so there is no point saying, "but what if it didn't work like that?" It does.

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Hi

I didn't read all the posts and I don't know how the subject is now the twin paradox, but I have some taught about the original question:

When a photon is released, which way does it head?

Some photon are realesed by excited atoms. Considering the law of conservation of momentum we can imagine a situation where we can predict the direction of the released photon.

Consider an atom at temperature close to 0K so it can be considered stationary.

Shot a photon from the left on that atom. If the atom absorb that photon , the conservation of momentum tell us that the atom will be moving to the left. After a while the atom is de-exited and emit a photon of the same momentum as the incident one, so the photon will continue in the left direction and the atom will stop.

Is it theoriticaly correct ?

Is it pratically correct ? (I guest that we cannot have a stationary atom because of Heiseinberg uncertanity)

Just a thaught

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Strange,

 

But acceleration is a change in speed over time. Isn't it? Don't you have to know speed and position and how the rate of change of speed is occurring to talk about acceleration? How can the acceleration be absolute, but the derivative not be. One might think you can not have speed without distance and time. Similarly how can you have acceleration if you have not already defined the space you are moving through in terms of time and distance, so that you can notice a rate of change?

 

Been thinking about this thread a lot, in terms of performing a thought experiment where spheres are within spheres, able to move on any axis. Place a dot on the outer sphere and orient the dot in the direction of the great attractor, and figure and contruct the thing so that the dot remains in that direction (from the center of the experiment) regardless of the motion of the Earth and Sun and Galaxy. Then, on a sphere inside that one, place a dot that is figured to stay pointing at the center of the galaxy. Then inside that, a sphere constructed to stay with its dot pointing at the Sun, and inside that, one pointing at the center of the Earth.

 

Probably not difficult from there to draw another symbol on each of the spheres, 90 degrees from the dot, showing the direction that sphere is going (with a velocity) around the thing the dot is oriented toward.

 

With such a device, either really contructed or just imagined, one could be aware of the different motions that the device was undergoing. And the different directions, that remained the same and moved in reliable repeatable sequences of relationships to each other.

 

With such an indicator one could orient an experiment to one or another of the spheres and keep it oriented a particular way, and see if there are any real things, fields, and forces that stay associated with one sphere, more than the others.

 

Would anything build up in or vacate a particular direction?

 

We know at least a ball bearing placed inside the Earth sphere would likely reside near the center of the Earth Dot.

 

What forces do we have at our disposal as the Earth passes through a magnetic line of force from the Sun? Is there any difference to anything that is with or against the direction we are going?

 

Regards, TAR

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Jacques,

 

I was not sure why you had the atom going to the left, when the photon came from the left?

 

However, if there was a laser firing from the left on a suitable group of atoms, I would guess that the secondary photons released from the atoms, might go in certain directions more than in others.

 

I apologize for bending the rules in mentioning this, but I have been thinking of an application of the 12 identical sections of the sphere, to this directional question. The Sperical Rhombic Dodecahedron has identical sections that can be regularly divided in quarters, and each quarter can be divided in quarters , down to whatever pixel resolution one would desire. Such a scheme allows for definite numbering and identification of each "direction" from the center that one of the divisions would represent.

 

Outfitting the inside surface of each of the Sperical Rhombic Dodecahederon "diamonds" with CCDs (charge coupled devices), one could count the incidence of photons going in each of the defined directions. All the directions would be represented with equal internal angle, and any regular deviation from random distribution could be identified and easily pictured (reproduced in color or whatever on another sphere similarly segmented).

 

Run the same experiment with the device locked on to Earth, or Sun, or Galaxy, and notice any deviations.

 

Regards, TAR


Thusly finding out if photons have a tendency to go in certain directions, for certain reasons.

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For instance, after establishing a predictable pattern of incident photons from a certain experimental setup, subject the whole experimental device to a strong magnetic field with the lines of force running in each of the 12 main directions and see if the pattern of incident photons changes in a predictable manner. Or a strong static/electric field.


Or a strong gravitational field.

 

My guess would be that there would be identifiable differences in the incidences of the photons on the CCDs in the different identified directions, for a combination of two different types of reasons. One, the different directional orientations of the fields might change the directional orientations of the atoms in the center of the experiment itself, thus causing the atoms to be "facing" in a certain direction when struck by the laser. And two, the space or air or vacuum between the center of the experiment and the CCDs might be conditioned by the fields into an arrangement that guided the photons in certain directions, or to borrow Mike Smith Cosmos's term, along certain "tubes of opportunity" or pathways.

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