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  • #16
    Originally posted by firstfloor View Post
    Great question Sparko.
    Light is a wave, it moves because it is a wave. Waves do not accelerate (even water waves do not accelerate). Electrons produced by Neutron decay also are waves and therefore adopt some non-zero speed the instant they are created, without being accelerated.
    Waves are created when energy moves through matter. Sound waves are expansion and compression of a material (like air) being moved by an object at a specific frequency. For example, a diaphragm moving back and forth. It pushes and pulls on the air molecules, pushing them outwards in a wave. The diaphragm is what is moving the air molecules in a wave.

    I am asking what moves the photons? Is there a force pushing them in a specific direction?

    Comment


    • #17
      Originally posted by Sparko View Post
      I am asking what moves the photons? Is there a force pushing them in a specific direction?
      The photon doesn't need any force to keep it going. As far as the photon itself is concerned, it travels no distance. This is also why it has no time to decay.
      Middle-of-the-road swing voter. Feel free to sway my opinion.

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      • #18
        Originally posted by Yttrium View Post
        The photon doesn't need any force to keep it going. As far as the photon itself is concerned, it travels no distance. This is also why it has no time to decay.
        But it does move and we can measure it moving. so the question remains.

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        • #19
          Originally posted by Sparko View Post
          Go away Frank. I don't want your input.
          Moderated By: rogue06


          As thread starter Sparko has officially requested that shunyadragon please stop posting in this thread. Please abide to this request and if you want to talk about photons please start another thread

          ***If you wish to take issue with this notice DO NOT do so in this thread.***
          Contact the forum moderator or an administrator in Private Message or email instead. If you feel you must publicly complain or whine, please take it to the Padded Room unless told otherwise.


          I'm always still in trouble again

          "You're by far the worst poster on TWeb" and "TWeb's biggest liar" --starlight (the guy who says Stalin was a right-winger)
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          "Of course, human life begins at fertilization that’s not the argument." --Tassman

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          • #20
            Originally posted by Sparko View Post
            But it does move and we can measure it moving. so the question remains.
            Technically, we can't actually measure an individual photon moving. We stop it when we measure it.
            Middle-of-the-road swing voter. Feel free to sway my opinion.

            Comment


            • #21
              Originally posted by Yttrium View Post
              Technically, we can't actually measure an individual photon moving. We stop it when we measure it.
              ok. but we can create a photon then detect when it hits a detector. and we know it doesn't just jump across the distance so we know it is moving.

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              • #22
                Originally posted by Sparko View Post
                ok. but we can create a photon then detect when it hits a detector. and we know it doesn't just jump across the distance so we know it is moving.
                Do we know that it doesn't just jump across the distance? Again, as far as the photon is concerned, there is no distance. We measure a distance and a time difference from launch to impact, which gives us a speed that the photon is travelling if it is moving through space. But we can't actually observe the photon moving over that distance, because any attempt we make to observe it stops it.

                In any case, from the photon's perspective, it needs no force to keep it moving across the distance, because there is no distance for it to travel. We view that from a different frame of reference, but that doesn't change the lack of need of a force.

                Of course, there is also the fact that thinks will keep moving at the same velocity unless acted on by a force. So an object travelling through space doesn't need a force to keep it moving, just to change its speed or direction.
                Last edited by Yttrium; 04-24-2017, 11:55 AM.
                Middle-of-the-road swing voter. Feel free to sway my opinion.

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                • #23
                  Originally posted by Yttrium View Post
                  Do we know that it doesn't just jump across the distance? Again, as far as the photon is concerned, there is no distance. We measure a distance and a time difference from launch to impact, which gives us a speed that the photon is travelling if it is moving through space. But we can't actually observe the photon moving over that distance, because any attempt we make to observe it stops it.

                  In any case, from the photon's perspective, it needs no force to keep it moving across the distance, because there is no distance for it to travel. We view that from a different frame of reference, but that doesn't change the lack of need of a force.
                  Yeah I guess to a photon the entire universe is two dimensional since time doesn't pass for it. but that doesn't answer my questions.

                  Comment


                  • #24
                    Originally posted by Sparko View Post
                    1. Why do photons move at all?
                    2. Why do they move at the speed they do instead of other speeds?
                    3. How do they move? what force propels them?
                    photons are particles of light beams, they have a zero resting mass, however when pulled together by an electromagnetic field they move quickly together, much like what we see in static electricitiy or a better example would be lightning. Bear in mind during a thunderstorm, clouds become electromagnetically charged with static via the elements that exist and pull one another together. because of this it creates well lightning which moves at 186,000 mph. the propulsion force in a thunderstorm is the electric attraction creating a light storm. Of course then we have many kinds of static that's emitted as the photon particles are attracted to each other via electron bonding. For example if something attracts the lighting toward the ground (say a power pole) there is a step leeder followed by an upward flash from the power pole connecting the two kinds of static. Storms clouds carry condensed water which is a great conducter of electricity, and all it needs is something else to attract it such as a lightning rod, a metal pole another cloud or charged air. of course the by pproduct of a storm is a sonic boom.
                    A happy family is but an earlier heaven.
                    George Bernard Shaw

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                    • #25
                      Originally posted by Sparko View Post
                      Waves are created when energy moves through matter. Sound waves are expansion and compression of a material (like air) being moved by an object at a specific frequency. For example, a diaphragm moving back and forth. It pushes and pulls on the air molecules, pushing them outwards in a wave. The diaphragm is what is moving the air molecules in a wave.

                      I am asking what moves the photons? Is there a force pushing them in a specific direction?
                      The photon has zero mass. If it were a classical particle of zero mass, any tiny force acting on it would immediately impart infinite acceleration because a = F/m. It’s not that. There is no force. Photons go in random directions from their source. They are simply emitted and absorbed OR created and annihilated and they travel at light speed through the electromagnetic field (the ‘medium’). The physics of photons is complicated but it is based on the quantisation of Maxwell’s equations.
                      “I think God, in creating man, somewhat overestimated his ability.” ― Oscar Wilde
                      “And if there were a God, I think it very unlikely that He would have such an uneasy vanity as to be offended by those who doubt His existence” ― Bertrand Russell
                      “not all there” - you know who you are

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                      • #26
                        Originally posted by firstfloor View Post
                        The photon has zero mass. If it were a classical particle of zero mass, any tiny force acting on it would immediately impart infinite acceleration because a = F/m. It’s not that. There is no force. Photons go in random directions from their source. They are simply emitted and absorbed OR created and annihilated and they travel at light speed through the electromagnetic field (the ‘medium’). The physics of photons is complicated but it is based on the quantisation of Maxwell’s equations.
                        OK that is what they do. My question is why and how? little rocket motors?

                        Comment


                        • #27
                          Originally posted by Catholicity View Post
                          photons are particles of light beams, they have a zero resting mass, however when pulled together by an electromagnetic field they move quickly together, much like what we see in static electricitiy or a better example would be lightning. Bear in mind during a thunderstorm, clouds become electromagnetically charged with static via the elements that exist and pull one another together. because of this it creates well lightning which moves at 186,000 mph. the propulsion force in a thunderstorm is the electric attraction creating a light storm. Of course then we have many kinds of static that's emitted as the photon particles are attracted to each other via electron bonding. For example if something attracts the lighting toward the ground (say a power pole) there is a step leeder followed by an upward flash from the power pole connecting the two kinds of static. Storms clouds carry condensed water which is a great conducter of electricity, and all it needs is something else to attract it such as a lightning rod, a metal pole another cloud or charged air. of course the by pproduct of a storm is a sonic boom.
                          Lightning doesn't travel at 186,000 mps - it moves about 1/3 of that speed. And electrons are not photons. Electricity is electrons. They give off photons as they change their orbits (basically they absorb energy and can jump to another atom if there is space for it, where they release the energy in the form of photons.

                          Comment


                          • #28
                            Originally posted by Sparko View Post
                            OK that is what they do. My question is why and how? little rocket motors?
                            Emission and absorption of photons has to do with jumps in the energy levels of electrons in atoms. The photon transfers that energy to where it is absorbed in another atom. When a photon is emitted, the atom recoils to conserve momentum. Photons have momentum by the correspondence of mass and energy.

                            Are we making progress?
                            “I think God, in creating man, somewhat overestimated his ability.” ― Oscar Wilde
                            “And if there were a God, I think it very unlikely that He would have such an uneasy vanity as to be offended by those who doubt His existence” ― Bertrand Russell
                            “not all there” - you know who you are

                            Comment


                            • #29
                              Originally posted by firstfloor View Post
                              Emission and absorption of photons has to do with jumps in the energy levels of electrons in atoms. The photon transfers that energy to where it is absorbed in another atom. When a photon is emitted, the atom recoils to conserve momentum. Photons have momentum by the correspondence of mass and energy.

                              Are we making progress?
                              So they are fired by an electron and move because of recoil?

                              If photons are absorbed anytime they hit a particle how does light even travel? There is no way it can go any measurable distance without hitting some atom in the air or in say a piece of clear glass.

                              Comment


                              • #30
                                Originally posted by Sparko View Post
                                So they are fired by an electron and move because of recoil?

                                If photons are absorbed anytime they hit a particle how does light even travel? There is no way it can go any measurable distance without hitting some atom in the air or in say a piece of clear glass.
                                I’m glad you brought this up Sparko because it is very surprising and I am enjoying learning about it.

                                The speed of light comes out of Maxwell’s equations once a couple of measurable constants (one electrical, one magnetic) and put into the equations. It is simply the speed that the wave goes no matter what energy it has. Nothing to do with impulses or recoils except that the photon has momentum by its velocity and energy.

                                When you look at the night sky, photons that have been travelling across space for hundreds and perhaps thousands of years (Eta Carinae on the limits of naked eye visibility is 7500 ly away) are annihilated by interaction with a molecule of the pigment retinaldehyde. Photons are not conserved. They do not age either – the spacetime distance between emission and absorption for any photon is zero (Relativity).

                                Why does light go through glass? – There are no energy levels available in glass (the electrons are tightly bound to atoms) to absorb visible light – there are for ultraviolet light – which gets absorbed.
                                “I think God, in creating man, somewhat overestimated his ability.” ― Oscar Wilde
                                “And if there were a God, I think it very unlikely that He would have such an uneasy vanity as to be offended by those who doubt His existence” ― Bertrand Russell
                                “not all there” - you know who you are

                                Comment

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