Existence

Hi Dr, Bur what causes the tracks to go past her at 0.5 c?God Bless,

Hi Taq, According to your diagram the driver would have to leave the interior of the car and be positioned directly over the laser pen, to be able to view what you have drawn.If I remember correctly the car is traveling at 0.5 c on a track in a vacuum.How does the driver survive in a vacuum?Your diagram does not match what reality would be.God Bless,

Hi Taq, So if there is no observer light can not travel at c in a vacuum?If there was no humans alive on earth to observe the light from the sun would that light still be proprogated at c?I have a sneaky feeling if there was no life forms on Earth the light from the sun would still travel at the same speed of c we observe it to travel at today.God Bless,

Hi crash, Yes.But never with a train on a parallel track. So I have never experienced such.But I have been in a car at a red light and made that observation of cars in other lanes.But I did not mistake there movement to be my movement. How would I be able to feel the motion of the train under me?The train would not be moving. But the track will move less than the width of a human hair relative to the car in the amount of time the photon takes to reach the detector.The car will move 2 feet relative to the track in the amount of time the photon takes to reach the detector.We are talking about the relative speed of one inertial frame to another inertial frame. In Taq's fantasy world but not in reality.God Bless,

Hi Dr, No, but it seems you did or did not read it.God Bless,

Hi Taq, Well actually the tracks are moving less than the width of a human hair while the car moves 2 feet. The road signs are moving at the speed the Earth is moving through our galaxy.I am going past the signs at 65 mph. All frames of reference are relative. I don't think that is the same as equal, but I could be wrong. Well the car is the instrument that is moving at 0.5 c relative to the tracks.The tracks are moving at 1 inch every 6.360593041943805e-6 nanoseconds relative to the car.The motion of the Earth is discussed at length in Message 837 if you are interested.God Bless,

Hi Taq, Thanks for telling me what I believe.I thought I believed the photon would strike the detector because the car is traveling at 0.5 c relative to the tracks and the pulse was emitted into the vacuum the car was traveling in, at a 90 angle relative to the motion of the car.Thus the photon would travel in a straight line until it hit something or was scattered. What does your example have to do with a photon traveling 4 feet in a vacuum? The photon will go in a straight line in a vacuum in the direction it is aimed.But in your case you would have to figure out where the spaceship would be at the moment the photon would intersect with the spaceship and aim at that point in space to be able to hit the spaceship with your aimed photon.Just like if you want the photon in my car experiment to hit the S instead of the D you would have to mount the laser pen at a 26.57 angle relative to the motion of the car.God Bless,

Hi NoNukes, No, I believe an enclosed reference frame is an enclosed reference frame not the definition of a reference frame. The reference frame that is enclosed inside the car is a non-inertial reference frame as everything inside the car is acted upon by an unbalanced force.Also the reference frame that is enclosed inside the car is not a vacuum as the driver could not survive in a vacuum. And it would hit the blackboard at the point aimed as both are in a non-inertial reference frame and are acted upon by an unbalanced force. Once you remove the sides the photon will not be acted upon by an unbalanced force and therefore will go in a straight line from the point emitted from the laser pen at a 90 angle relative to the motion of the blackboard.Since the chalkboard is 4 feet from the laser pen which is aimed 6 inches to the right of the rear of the blackboard relative to the direction of travel the blackboard which is traveling at 0.5 c the pulse will miss the blackboard.The photon does not veer off at a 26.57 angle it goes in a straight line from the point emitted at a 90 angle relative to the motion of the blackboard. Physical objects do take on the motion of the emitter.Photons do not take on the motion of the emitter.So no they will not act the same. No, but the wind would cause the juggler a lot of problems.Why do you jump from happenings in a vacuum to real world happenings for comparison? There would be no vacuum inside the enclosed car or the driver could not surive.The reference frame inside the car is acted upon by unbalanced forces and therefore is not an inertial frame of reference.Question:Can photons take on the motion of the emitter as bowling balls do?God Bless,

Hi Panda, Are you saying reality has nothing to do with a thought experiment?I thought we were trying to understand exactly what would happen in reality by using a thought experiment, silly me.Astronauts do not survive in a vacuum. They have spacecraft to travel in and when working on the outside of the spacestation they wear spacesuits.How long would one of the astronauts survive outside the spacestation without a spacesuit on?God Bless,

Hi NoNukes, I never gave any discription of the surroundings of the NoNukes observer. But if NoNukes was standing on the Salt Lake Flats in a vacuum he would need some sort of spacesuit to protect him, or he would not be conscious very long.The observer NoNukes would not see where the laser pen was when the photon was emitted. He would observe the light to flash when the photon hit the detector.For the observer NoNukes to be able to see the position of the laser pen when the photon was emitted he would need a super fast camera that could record the entire process and then be able to show it on a screen and slow it down to where the car was only traveling a few miles per hour. The human eye would not even see the car go by. The driver can either observe the laser pen and the detector or he can not observe the laser pen and the detector.So for the driver to observe what Taq drew would require the driver to be outside the car above the laser pen. But we were talking about the driver observing the pulse hit the sensor rather than the detector.We were not talking about what the driver could draw. QUESTIONS:So will a photon emitted in a vacuum travel in a straight line from the point emitted regardless of the motion of the emitter?Is an inertial frame one in which the motion of a particle is not subject to an unbalanced force and travels in a straight line at constant speed?Is a non-inertial frame one in which the motion of a particle is subject to an unbalanced force and does not travel in a straight line?God Bless,

Hi NoNukes, Anything traveling from side to side in the car would have an unbalanced force exerted upon it creating a non-inertial frame.That is the only way the photon can hit the point the laser pen is aimed at, just like in the classroom.God Bless,

Hi Dr, What are the physics under discussion?The car is traveling in a vacuum at 0.5 c relative to the tracks that are attached to the Salt Lake Flats.On the back of the car is mounted a frame with a laser pen mounted at a 90 angle relative to the motion of the car 4 feet above sensors and detectors on the track.The sensors and detectors are exactly 2 feet apart.There is a sensor on the bottom of the frame that when it passes over the sensor that causes a signal to be sent to the laser pen and causes it to emitt a photon when the laser pen is directly over the detector which has a light attached that will light when hit by the photon.The car moves exactly 2 feet in the time it takes for the photon to travel the 4 feet to the detector."IF" the photon travels in a straight line at a 90 angle relative to the motion of the car, from the point emitted from the laser pen at it will hit the detector every time."IF" the photon does not travel in a straight line at a 90 angle relative to the motion of the car, it will not hit the detector.So the only physics we are discussing is, does the photon travel in a straight line from the point emitted by the laser pen?Either it does or does not there is no inbetween.NoNukes and Taq have been trying to convince me that the photon will travel at a 26.57 angle relative to the motion of the car and hit the sensor rather than the detector. Even though the laser pen is mounted at a 90 angle relative to the motion of the car.Einstein's postulate # 2 says:

quote:

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2. Second postulate (invariance of c)
As measured in any inertial frame of reference, light is always propagated in empty space with a definite velocity c that is independent of the state of motion of the emitting body.

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SourceAccording to postulate # 2 the light is propagated in a vacuum at c independent of the state of the motion of the emitting body."IF" that is true the photon will hit the detector and cause the light to flash.An inertial reference frame which is under discussion says:

quote:

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An inertial frame of reference is one in which the motion of a particle not subject to forces is in a straight line at constant speed.

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SourceI am arguing these two are true, but am being told they are false as the photon will travel at at a 26.57 angle relative to the motion of the car, which is not in a straight line relative to the laser pen which is mounted at a 90 angle to the motion of the car.Would you care to explain to me how postulate #2 can be true and the photon miss the detector?God Bless,

Hi NoNukes, But the blackboard moves 2 feet from the point the photon is emitted, therefore an unbalanced force is required for the photon to hit the blackboard.If there is no unbalanced force on the pulse to cause it to travel in the direction of the motion of the car for 2 feet from the time emitted the photon will miss the blackboard.Or the laser pen would have to be aimed at the spot the blackboard was going to be when the photon had traveled the 4+ feet between the laser pen and the blackboard while the car traveled the 2 feet. The forward motion of the car exerts an unbalanced force on the photon that is traveling at a 90 angle relative to the motion of the car. Just like in a classroom with the blackboard on the north or south wall, an unbalanced force is exerted on the photon, just not as much as in the car. In the open the car which is traveling in a straight line at a constant speed we have an inertial reference frame in which the photon has to travel in a straight line from the point emitted from the laser pen. So when the car moves the 2 feet in the time required for the photon to travel 4 feet the photon will miss the blackboard.I don't understand why this is so hard to grasp.If you wanted to hit an airplane with an anti-aircraft gun where would you aim to hit it?Would you aim at the airplane? If you do you will miss it.To hit the plane you have to aim where the plane is going to be when the flack reaches the height the airplane is flying at.Once the bullet leaves the end of the gun barrel you can not change the direction of that bullet, unless it is bounced off an object that exerts an unbalanced force on the bullet.Once the photon leaves the end of the laser pen you can not change the direction of that photon without adding an unbalanced force. If there is no unbalanced force applied to the photon by the motion of the car, what causes the photon to hit the blackboard after the blackboard has moved 2 feet from the time the photon was emitted?This is the same thing we were discussing when I enclosed the photon in the tube on the light clock on the cycle. You get the same results.God Bless,

Hi NoNukes, It would be much easier to just read what I present. Relative to what does the photon travel at a 26.5 angle?I will restate what I believe for you. Pay close attention to the words I use.If the photon is released from a laser pen traveling at a 180 angle relative to the laser pen it will go in a straight line at c until it hits something and scatters or is absorbed. Unless the direction of the photon is changed by an unbalanced force.Einstein's postulate # 2 says:

quote:

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2. Second postulate (invariance of c)
As measured in any inertial frame of reference, light is always propagated in empty space with a definite velocity c that is independent of the state of motion of the emitting body.

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SourceAccording to postulate # 2 the light is propagated in a vacuum at c independent of the state of the motion of the emitting body.An inertial reference frame which is under discussion says:

quote:

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An inertial frame of reference is one in which the motion of a particle not subject to forces is in a straight line at constant speed.

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SourceTherefore, if the car is traveling at zero relative to the tracks on the Salt Lake Flats with the laser pen mounted at a 90 angle relative to the position of the car on the tracks, if a photon is emitted from the laser pen it will travel in a straight line across the car and hit the opposite side of the car.If we mount a detector at the spot on the car that the photon hits as long as the car is sitting still relative to the tracks the photon will hit the detector.I think we would be in agreement so far.But when the car is put into motion and reaches 0.5 c using the distance for the photon to travel being 4 feet if the photon travels in a straight line at c it will not hit the detector unless the photon is acted upon by an unbalanced force.You disagree and say the photon will hit the detector.But for the photon to hit the detector the photon must travel at a 26.5 angle relative to the direction it was traveling when it was emitted from the laser pen.You have presented no mechanism whereby the photon can change its direction and hit the detector which has moved 2 feet in the time it took for the photon to travel 4 feet.The laser pen is mounted at a 90 angle relative to the motion of the car.So, what changes the direction of the photon to cause it to hit the detector?Now if we go back to the car on the tracks that are mounted to the Salt Lake Flats with the frame on the rear of the car with the sensors and detectors and modify the laser pen to emitt a laser beam when it is trigered rather than a photon the first photon would hit the detector and there would be a solid laser beam hitting the sensors and detectors until the laser pen is turned off.I don't think you will disagree with this as you can produce such an experiment by pointing your laser pen at the ceiling on one side of the room holding the on button down and moving your hand where the beam makes a solid line on the ceiling in any direction you point the laser pen.So the only thing we disagree about is the direction the photon will travel when emitted from the laser pen.I believe the photon will travel in a straight line in the direction it is emitted traveling in unless that direction is changed by an unbalanced force.I think that is in agreement with postulate #2 and the definition of an inertial frame.The photon is traveling at c independent of the emitter.
The photon is traveling in a straight line in the direction emitted.Your claim is that the photon is traveling at a 26.5 angle relative to the direction it was traveling in when it was emitted from the laser pen.What causes that change in direction of travel?God Bless,

Hi crash, The laser pen is not mounted at a 180 angle relative to the motion of the car.The laser pen is mounted at a 90 angle relative to the motion of the car.The photon emitted from the laser pen will travel at c across the car to the oposite side.If the car is traveling at a constant speed of 0.5 c the car will move 2 feet in the time it takes the photon to travel 4 feet from the laser pen to the oposite side of the car and hit a detector.If the detector is mounted where the photon will strike the detector when the car is moving zero relative to the tracks on the Salt Lake Flats, it will miss the detector when the car is traveling at 0.5 c relative to the tracks on the Salt Lake Flats unless the photon is acted upon by an unbalanced force.The photon is not traveling in the same direction as the car is traveling. No unbalanced force can be added to the photon as per the definition of postulate #2.The photon is traveling horozontal to the travel of the car in a straight line and to hit a target that has moved 2 feet from the time the photon is emitted requires an unbalanced force be applied to accomplish this feat.Unless the laser pen is mounted at a 26.5 angle relative to the motion of the car to cause it to hit the target 2 feet from where it was when the photon was emitted.The problem is the laser pen is mounted at a 90 angle relative to the motion of the car.God Bless,