Existence

You tell me. You are the one arguing for an Aether.

The line connecting the point where the photon is produced to the point where the photon is detected is determined by the movement of the car. In the example where you put a photon detector on a pole in the previous post the less than vertical path observed by an outside observer is due to the motion of the car relative to the outside observer. That is, unless you want to invoke the Aether once again. According to who, the person in the car or the person outside of the car? When magazines list the muzzle velocity of a rifle do they also add in the speed of Earth's rotational and oribtal speed, not to mention the speed at which the Earth is moving around the Milky Way?In the car's inertial frame the bullet's velocity is the muzzle velocity only.

Hi Taq, If the sensor is attached to the top of the pole on the face of the pole and I can stick my laser pen through the roof 1" from where the pole is attached to the roof, the pole being only 4 feet tall.I hit the button on the pen and make a flash which starts towards the sensor.The pen is traveling at 149,896,229 meters per second.The light flash is traveling at 299,792,458 meters per second.The light flash is traveling twice as fast as the car.If the sensor protrudes 8 inches from the pole by the time the flash can reach the height of the sensor the pole will have moved 2 feet. Since the flash of light can not take on the velocity of the car the flash will miss the sensor by 12 inches.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

Hi Taq, Pass whatever that is you are drinking or whatever as I need to get to sleep and I think that would help.I never gave an example where I put a pole on a car that was your example. According to you. You are the one who said the car was traveling at velocity 0.5 c.So if the car is traveling at 149,896,229 meters per second whatever is inside that car is traveling at 149,896,229 meters per second.Since the gun is traveling faster than the bullet can travel the bullet will not exit the barrel of the gun UNLESS THE BULLET CAN ACQUIRE THE VELOCITY OF THE CAR.Which it does. And when it does exit the barrel of the gun I can't oberserve it anyway.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

I did use that example. Perhaps you should read that post. Yes, to the observer outside of the car. What about the driver's frame of reference? If we set up a device on the hood of the car that could measure the speed of the bullet what speed would it say the bullet is travelling?

So you are once again invoking an Aether. Sorry buddy, that idea was thrown out long ago. It was falsified by the Michelson-Morley experiment. If what you describe does happen then they should have seen a change in the interference patterns when they moved the light path into and away from the movement of Earth. No change was observed.The photons do not deviate from that path. They hit the sensor dead center, as long as your velocity does not change while the photons are travelling towards the sensor.

Hi Taq, If the bullet could reach the hood of the car it would be traveling faster than the car.Do I believe the bullet could reach the hood? Yes but I don't know if it would or not, because a test can not be run to prove one way or the other.But if it could reach the hood it would be traveling faster than 149,896,229 meters per second. Because that is what the hood is traveling.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

We are obviously ignoring wind resistance for this thought experiment. So what would the chronograph on the hood of the car record as the speed of the bullet if the standard muzzle velocity of the gun is 1,000 feet/second? For the driver's frame of reference, the speed of the hood is zero.

Hi ICANT,I couldn't resist the opportunity to apply some physics after reading this exchange between you and Taq.But first let me comment on the exchange itself. In fact they can both be true as long as "taking on the motion" does not mean increasing or decreasing the speed of a photon in a vacuum in any inertial reference frame.What we have is you failing to wrap your head around an idea and repeating some endless mantra. SR is completely consistent with postulate #2 as you cite it here. Even with the differing directions of light as viewed in different reference frames the velocity remains "c" regardless of the speed of the source. The postulate does not require anything else.Of course you want to require more so that you can find a failed prediction of SR.Your behavior is exactly the same as in your "show me where the math is wrong" repeated mantra from a couple hundred posts ago. Your sixth grade math was not wrong; it was irrelevant. Similarly, the fact that SR does not follow your interpretation of postulate #2 is of no consequence. You have admitted that you don't claim to understand Einstein's work. Postulate #2 is just one more thing you just don't get.Further, you don't even accept your own interpretation of postulate #2. Do you accept that light always travels at "c" in every inertial frame? It is evident that you do not, or you could not insist that a light beam travels through empty space at only 0.5 c in the space cycle frame of reference. Yet you state exactly this and are not the least bit bothered by the inconsistency.Personally, I would not use the phrase "take on the motion" of the source. That concept does not explain the result when we consider the frame of the light source to be the "stationary frame". According to postulate #1, the physics as observed in inertial reference frames must give the correct result regardless of which frame is considered stationary. Simple non-relativistic mechanics using sixth grade math does not yield results consistent with experiment. Insisting that I check your ability to subtract is not an argument.The bottom line is, nobody on either side of the debate, would accept postulate #2 as you interpret it. Fortunately, special relativity does not descend from your interpretation of postulate #2.In case some lurkers are starving for some real hoofing (er, real physics) let's actually apply an SR prediction to the space ship/headlight problem. Einstein predicts that when we combine two velocities which are along a single direction, we should use the following (previously introduced) equation. The equation can be found in section 5 of Einstein's 1905 Special Relativity paper, rather ineffectively "hidden" under the simple descriptive heading 5. The Composition of Velocities. For non-German speakers, a translation of the paper can be found hereAs has been pointed out (See Message 592), this equation produces answers consistent with sixth grade math answer when u and v are small compared to c. For example, we get the expected result when 'u' is the muzzle velocity of a rifle and 'v' is the speed of a helicopter from which a politician (not ICANT) is hunting moose. That bullet does smack the moose harder when the helicopter is traveling in the direction of the moose.However for velocities that are a significant fraction of c, the equation gives a different result. The combined velocities can never exceed "c".Einstein notes a consequence for this equation that is relevant to the current discussion.

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It follows, further, that the velocity of light c cannot be altered by composition with a velocity less than that of light. For this case we obtain.

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Note that the combination of any velocity with the speed of light always yields the speed of light as a result. For example, if the space cycle is traveling at 0.5c, and the head light is turned on, at what does the velocity travel.ABE:For ICANT: so it is not that velocities cannot be combined with "c" it is that the result of the combination always yields speed c.[End of ABE]If instead, the tail light is turned on, resulting velocity is Identical to the first case.Of course, if we use the space ship as our inertial frame, the equations produce the trivial result that , with v = 0, and w = the speed of light, the composite velocity V is also "c".So even if a light beam "takes on the motion" of its source, the resulting velocity (in any reference frame), according to the equations above would still be "c", exactly as required by postulate #2.So there simply is no inconsistency between SR and postulate #2. ICANT is simply misreading science papers (and wikipedia) and howling at the moon.And despite ICANTs protests that none of this stuff has been verified experimentally, SR accurately predicts the trajectories of particles in collisions in accelerators between particles having velocities greater than 0.9999c. He's simply wrong about that too. Edited by NoNukes, : Clarify combinations of velocities always yields c. Edit is marked.Edited by NoNukes, : Fix latex tag. Somehow I messed it up doing edit

Hi Taq, No I am invoking your statement you made in Message 745

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It is saying that the velocity of the body and the velocity of light are not additive.

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The pole is mounted to the top of the car.The care is moving at 149,896,229 meters per second.The light pulse is released flush with the surface of the roof of the car.The sensor is mounted 4 feet from the roof of the car on a pole.

The car, pole, sensor moves---------->2 feet.
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The light pulse starts its journey at S. 

The periods are just to keep the formating from changing.Now if the light pulse when flashed at S can not take on the forward motion of the car it will proceed in the direction pointed regardless of what the car does.Since the car is moving the pole will move 2 feet from the time the pulse is released.The sensor protruding only 8 inches from the pole and the pen 1 inch from the pole means the pen is aimed at a point 1 inch from the pole leaving only 7 inches to edge of sensor.The pulse will reach the point the sensor was after the sensor has moved 2 feet meaning the pulse will miss the sensor by over 12 inches.Your claim is that:

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The photons do not deviate from that path.

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For the pulse to hit the sensor dead center as you claim the pen would have to be aimed at a position 2 feet in front of the position the sensor is when the pulse is released. Which would cause a problem unless the pen and sensor was mounted on the side of the pole.I will agree that if you aim the pen at the position the sensor will be when the car has moved moved 2 feet it will hit the sensor dead center.But since it is aimed at the sensor where it won't be when the car moves 2 feet there is no way for the pulse to hit the sensor.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

Hi Taq, Maybe my problem is I don't understand what a vaccum is, could you explain it to me.In air conditioning when you pull a vaccum on the system you remove everything from inside the system by pulling a vaccum for 24 hours. Then you put the freon in the system. Since a vaccum is pulled there is no resistence in the system to hinder the freon traveling through the system.So if we are in a vaccum there is a void of resistence of any kind. That includes an Aether. If there is no resistence or drag, explain how the pulse of light is draged the 2 feet necessary for the pulse to hit the detector dead center.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

That isn't the problem. Your problem is understanding inertial frames. There is no preferrential inertial frame. IOW, there is no point in the universe that is considered to have zero velocity to which everything else (e.g. planets, bicycles, galaxies) is compared. Every non-accelerating inertial frame is considered to be at rest within that frame of reference. Let me repeat that again . . . Every non-accelerating intertial frame is considered to be at rest within that frame of reference.So let's go back to the car with the light sensor on a pole. In this example, if the car is not accelerating, no matter what speed it may be going compared to another object, then the light will hit the center of the sensor because it is considered to be at rest within that inertial frame. Then what is pushing the light off course in the inertial frame of the car? The car is not accelerating, therefore it is considered to be at rest within the inertial frame of the car. It's not being dragged. That's the whole point. You are refusing to understand what an inertial frame is.I have also mentioned the Michelson-Morley experiment which you can learn about here. Please look at the experimental design. Please understand how it refutes your complete butchering of Relativity. When I say that the Michelson-Morely experiment refutes your claims I am not kidding. It really does. If what you say is true then the interference patterns should change depending on the path of the light in the interferometer. If the path of the light is running parallel to the orbit and revolution of the Earth then there is no problem. If it runs perpendicular to the rotation and orbit of the Earth then it should move across the mirrors and produce a different interference pattern. IT DIDN'T!!! The interference patterns were the same regardless of their position with respect to the motion of the Earth. The light hit the dead center of the mirror where it was supposed to no matter the relationship was between the path of the light and the motion of the Earth. The car experiment we are discussing is the same exact thing as the Michelson-Morley experiment.

You are doing a rather poor job of it. I will completely agree that the speed of the light leaving the car is 3E8 m/s along the path between the point where the photons are produced and the point at which they are detected.It might be more productive if you also address the train experiment in post #748. Here it is again:Imagine that light is moving parallel to a set of infinitely long railroad tracks. You get on a train and start accelerating at high speed in the direction of the light beam. Let's say that you are somehow able to see the light as it passes the train. When the train is travelling at 0.5c how fast do you see the light passing you? When the train is travelling at 0.99c how fast is the light going as it passes you by?Just to move the discussion along, the answer to both questions is c. No matter how fast you go the light will be passing you at 3E8 m/s. A person standing to the side of the railroad tracks with no velocity relative to the tracks will also observe that same light going by at 3E8m/s. So how can this be? The answer is that time has slowed down in the train's inertial frame compared to the inertial frame of the person standing by the tracks.

Hi NoNukes, If the pulse of light is traveling at 299,792,458 meters per second, how does it add any speed without breaking the speed of light.You quoted Einstein that "that the velocity of light c cannot be altered by composition with a velocity less than that of light".I take that to mean you can't add 1 meter per second to the speed of c in a vaccum.You then gave an equation showing the headlight can not add the speed of the cycle to it, but will travel at 299,792,458 meters per second.You also gave an equation showing the forward motion of the cycle would not affect the speed of the tail light, as the beam would travel at the speed of 299,792,458 meters per second.Do you have an equation that shows that the speed of the beam causes the cycle to stop in mid vaccume?OR do you have an equation that shows the light pulse traveling at 299,792,458 meters per second affects the 149,896,229 meters per second the cycle is traveling at?Why can't the pulse travel at 299,792,458 meters per second while the cycle is traveling at 149,896,229 meters per second? No.That is not what postulate #2 says.

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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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That says "light is always propagated in empty space with a definite velocity c."Maybe I don't understand what empty space is. As I understande what Einstein was talking about he was talking about a vaccum as he mentions several times.But empty space would be exactly that empty. There would be no particle of any kind in that space that would have the possibility of impeeding the motion of the light or the cycle. In any direction they are traveling.So my question to you is:In my cycle experiment with the open clock or the train flatcar with the open clock the light pulse is traveling at a 90 angle to the two mirrors which are 1 meter apart and 18 inches long.Since the speed of the light is 299,792,458 meters per second it will take 3.33564095198152 nanoseconds for the light pulse to reach the top mirror.In that same time the train or cycle will travel 1/2 meter.It is 9 inches from the center of the top mirror to the back edge.It will take the mirrors 1.525058093362138 nanoseconds to travel the 9" to the edge of the top mirror.That means that if something does not alter the straight line direction of the light pulse from the 90 to the bottom mirror the pulse of light will miss the top mirror.What would you propose to alter the direction of the pulse so it would hit the top mirror?In Message 689 to Son which you replied to I ask that the math be shown where it was wrong.In Message 710 You replied with a lot of smoke and mirrors but you did not show where the math was wrong.So could you explain to me what would cause the light pulse to hit the top mirror in the center.If the motion of the cycle or train alters the direction of the light pulse, wouldn't that force exerted on the light pulse cause the light pulse to accelerate?God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

Hi Taq, If I can see the light beam it has already passed me.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."