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Author Topic:   Existence
DrJones*
Member
Posts: 2293
From: Edmonton, Alberta, Canada
Joined: 08-19-2004
Member Rating: 5.5


Message 1156 of 1229 (632373)
09-07-2011 1:34 PM
Reply to: Message 1152 by Buzsaw
09-07-2011 12:00 PM


Re: Inertial reference frames ... again
ΣF=ma
Edited by DrJones*, : No reason given.

This message is a reply to:
 Message 1152 by Buzsaw, posted 09-07-2011 12:00 PM Buzsaw has not replied

Taq
Member
Posts: 10158
Joined: 03-06-2009
Member Rating: 4.4


(1)
Message 1157 of 1229 (632377)
09-07-2011 2:27 PM
Reply to: Message 1147 by ICANT
09-07-2011 10:06 AM


Re: Inertial reference frames ... again
Therefore, 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.
The detector is not moving relative to the pen laser. It does not move during the entire transit of the photon. It doesn't matter how fast the Salt Flats are moving by in the window since we are not trying to hit anything on the Salt Flats. We are trying to hit a detector that is NOT MOVING relative to the pen laser.
If the target is not moving relative to the pen laser then the photon will strike the detector IN ALL INERTIAL FRAMES. There is no golden inertial frame to which everything is compared. The Michelson-Morley experiment demonstrates this in spades. They ran this very experiment, and the photons strike exactly where we say they should strike, and not where you say they should strike. Real experiments have proven your wrong.
So, what changes the direction of the photon to cause it to hit the detector?
What canges the direction of the photon so that it doesn't hit the detector, according to you? The pen laser is aimed right at the detector, and the detector is still right in front of the pen laser when the light transits the distance between them. So what pushes the photon off course?
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.
That would only happen if the photon travelled the distance between the car and the tracks instantaneously. Light does not travel instantaneously. When the photon travels the distance between the pen laser and the tracks it will hit the second sensor since that sensor is directly below the pen laser when the photon travels that distance.
It is quite strange that in the first scenario you claim that the detector travels four feet when in fact the detector is not moving relative to the pen laser. In the second scenario the detector is moving relative the pen laser and yet you claim that it will hit the detector. Why so bass ackwards?
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?
There is no change. The photon is directly between the pen laser and the tracks (at a 90 degree angle) at all times as viewed by all observers.
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.
So what unbalanced force is pushing the photon backwards in your scenario? Why isn't the photon directly below the pen laser at all times which is the direction it was emitted?
Edited by Taq, : No reason given.

This message is a reply to:
 Message 1147 by ICANT, posted 09-07-2011 10:06 AM ICANT has not replied

NoNukes
Inactive Member


(1)
Message 1158 of 1229 (632382)
09-07-2011 3:03 PM


Simulation showing motion in reference frames.
The link below is to an animation of motion along a river. The simulation can show the motion of objects in different reference frames.
Retired Service | The University of Vermont
You can show the motion of the boats and a person in different reference frames. When your mouse is over an object (ground, river or boats) then the display shows things in the inertial reference frame in which that object is at rest.
The most interesting display is the one with the person moving across the river. The directions to accomplish this are a little confusing, but you can give the person a vertical velocity to make her move across the river. Then you can select different reference frames to see that the persons angle across the river does change with the reference frame.
Note that only regular old Newtonian mechanics is at work. Special relativity, not required.
Maybe the simulation will help aid someone in understanding the math/geometry involved in making measurements in different reference frames. One can only hope...

crashfrog
Member (Idle past 1553 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 1159 of 1229 (632386)
09-07-2011 4:58 PM
Reply to: Message 1148 by ICANT
09-07-2011 10:25 AM


Re: Inertial reference frames ... again
The laser pen is not mounted at a 180 angle relative to the motion of the car.
I have not made any claim that it was.
The laser pen is mounted at a 90 angle relative to the motion of the car.
You mean to say that the laser emitter is mounted transverse to the axis of travel. Yes, I think everyone understands that (but you, apparently.)
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.
But the car is not the only thing moving .5c in that direction. The laser pen has the same velocity (as measured from the same reference frame) and, as a consequence, the velocity of the laser light being emitted from it has a vector projection on the axis of travel of .5c as well.
That's not saying that the velocity of light is .5c; that's saying that if you considered only the vector component of the light's velocity in the axis of the car's motion, it would be .5c. That is why, in the reference frame of the car, the laser light travels exactly transverse to the axis of motion of the car.
The photon is not traveling in the same direction as the car is traveling.
No, of course not. But the motion vector of the car is a component of the motion vector of the light. That is why the laser in the car hits precisely what it is aimed at, it doesn't veer off towards the rear of the car. If that was ever the case we could all violate relativity at will and determine our absolute velocity anywhere in the universe by means of flashlights, which clearly nobody is able to do.
No unbalanced force can be added to the photon as per the definition of postulate #2.
It's not necessary to add a force to the light; it's already going in exactly that direction.
The problem is the laser pen is mounted at a 90 angle relative to the motion of the car.
No, exactly wrong. The solution is that the laser pen is mounted transverse to the axis of the car's motion across the salt flat.

This message is a reply to:
 Message 1148 by ICANT, posted 09-07-2011 10:25 AM ICANT has not replied

crashfrog
Member (Idle past 1553 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 1160 of 1229 (632387)
09-07-2011 5:03 PM
Reply to: Message 1152 by Buzsaw
09-07-2011 12:00 PM


Re: Inertial reference frames ... again
How does that size up to 3LoT, in that there is no perpetual machine?
Firstly 3LoT states that the entropy of a pure, perfect crystal at zero kelvin is zero, not anything about perpetual motion machines. Secondly, we're assuming a frictionless car because that's a common simplification made in physics problems. Everybody knows what friction does - it turns kinetic energy into heat. (As it happens, it doesn't matter - the second law disallows even frictionless perpetual motion machines.)
Thirdly there's nothing to "size up"; a body in simple constant motion in an empty universe isn't a "machine" in any thermodynamic sense.

This message is a reply to:
 Message 1152 by Buzsaw, posted 09-07-2011 12:00 PM Buzsaw has not replied

Boof
Member (Idle past 332 days)
Posts: 99
From: Australia
Joined: 08-02-2010


(1)
Message 1161 of 1229 (632399)
09-07-2011 8:07 PM
Reply to: Message 1151 by ICANT
09-07-2011 11:31 AM


Re: Inertial reference frames ... again
ICANT writes:
So you are in agreement with me that the photon travels at a 90 angle relative to the motion of the car.
Wouldn't that be true in every inertial reference frame?
No!
In the inertial reference frame of the car, the car is stationary and the photon travels at an angle of 90 relative to the motion of the tracks which are moving at 0.5c. I'm sure this has been explained many times.
Edited by Boof, : Tired some formatting. It was fun.

This message is a reply to:
 Message 1151 by ICANT, posted 09-07-2011 11:31 AM ICANT has replied

Replies to this message:
 Message 1163 by ICANT, posted 09-08-2011 4:43 AM Boof has replied

ICANT
Member (Idle past 113 days)
Posts: 6769
From: SSC
Joined: 03-12-2007


Message 1162 of 1229 (632446)
09-08-2011 4:35 AM
Reply to: Message 1155 by NoNukes
09-07-2011 1:15 PM


Re: Inertial reference frames ... again
Hi NoNukes,
NoNukes writes:
Your position is that one of Einstein's postulates used to generate special relativity is actually inconsistent with SR. I'm open to having you demonstrate that, but you aren't going to make a successful argument without knowing even what an inertial reference frame is.
My position is that if Einsteins two postulates and Newtons laws are correct the photon can not hit the detector in the car, unless an unbalanced force is applied to the photon.
| = laser pen
. = photon
> = direction of travel
! = photon emitted from laser pen
D = detector, blackboard

_______________>>>>>>>>>>>>>>>>>>
|2 feet in distance|
P P P P P P P P P P
!
.
.
.
.
.
.
DDDDDDDDDDDD
________________>>>>>>>>>>>>>>>>>> 
If the photon travels in a straight line in the direction it is emitted at the first P it will hit the first D.
If the photon hits the last D the photon has to move two feet in the direction the car is traveling relative to the point the photon is emitted.
That means that the photon would have to take on the motion of the emitter which is forbidden.
The Salt Lake Flats is in Utah and the earths revolution would be less there than the equator. But I will use the Equator speed, of 1000 mph.
It takes 4.066813452804019 nanoseconds for the proton to travel 4 feet, and for the car to travel 2 feet.
The earth moves 1,818.028285941509 nanometers in the same time it takes the photon to travel the 4 feet across the car.
So the track is traveling at constant speed of 1,818.028285941509 nanometers per second relative to the car.
The car is traveling at a constant speed of 0.5 c relative to the tracks.
So when you or anyone else tells me the car is at rest it is still moving at 0.5 c relative to the tracks.
NoNukes writes:
I think it is about summary time.
Why do you think it is summary time?
You have not even addressed the OP yet, even though I mentioned it a couple of times.
From Message 1
quote:
Is existence responsible for bringing into existence all that exists?
If not, then what is responsible for bringing into existence all that exists.
The Bible declares existence is responsible for bringing into existence all that exists.
I agree.
What say you?
If existence is not responsible for bringing into existence all that exists, then what is?
There is existence (all things exist) and the opposite of that is non-existence (no thing exists). There is no known mechanism whereby existence can begin to exist from non-existence.
Can anyone present a case for existence without it being brought about by existence?
God Bless,

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

This message is a reply to:
 Message 1155 by NoNukes, posted 09-07-2011 1:15 PM NoNukes has replied

Replies to this message:
 Message 1165 by NoNukes, posted 09-08-2011 9:53 AM ICANT has not replied
 Message 1167 by Stile, posted 09-08-2011 10:43 AM ICANT has replied
 Message 1169 by crashfrog, posted 09-08-2011 10:47 AM ICANT has replied

ICANT
Member (Idle past 113 days)
Posts: 6769
From: SSC
Joined: 03-12-2007


Message 1163 of 1229 (632448)
09-08-2011 4:43 AM
Reply to: Message 1161 by Boof
09-07-2011 8:07 PM


Re: Inertial reference frames ... again
Hi Boof,
Boof writes:
the car is stationary
The car is not stationary. You can say it is at rest but you can't say it is stationary.
The car is traveling at a constant speed of 0.5 c relative to the tracks.
The tracks are traveling at a constant speed of 1,818.028285941509 nanometers per second relative to the car.
So neither one is stationary.
Everything is moving relative to something.
God Bless,
And welcome to EvC.

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

This message is a reply to:
 Message 1161 by Boof, posted 09-07-2011 8:07 PM Boof has replied

Replies to this message:
 Message 1164 by Son, posted 09-08-2011 8:48 AM ICANT has not replied
 Message 1166 by NoNukes, posted 09-08-2011 9:59 AM ICANT has replied
 Message 1168 by crashfrog, posted 09-08-2011 10:46 AM ICANT has replied
 Message 1170 by Taq, posted 09-08-2011 11:11 AM ICANT has not replied
 Message 1205 by Boof, posted 09-08-2011 6:58 PM ICANT has not replied

Son
Member (Idle past 3916 days)
Posts: 346
From: France,Paris
Joined: 03-11-2009


Message 1164 of 1229 (632482)
09-08-2011 8:48 AM
Reply to: Message 1163 by ICANT
09-08-2011 4:43 AM


Re: Inertial reference frames ... again
That's why he says "stationnary". If stationary meant something that didn't move relative to anything, nothing would be stationary and the word wouldn't make sense.
ICANT writes:
The car is traveling at a constant speed of 0.5 c relative to the tracks.
The tracks are traveling at a constant speed of 1,818.028285941509 nanometers per second relative to the car.
As for my previous posts, I'm sorry I badly explained things to you, but it's because I thought you were middle school level at least, but it seems you dropped out of middle school (not high school as I assumed).
It's obvious that if the car moves at a constant speed of 0.5 c relative to the tracks, then the tracks are traveling at a constant speed of 0.5 c relative to the car. Even a middle schooler wouldn't make the mistake you did.
As for inertial frames, NoNukes gave you a link in message 1158 that could explain it to you. Hopefully, you will learn something (though I doubt it given your very low level).
As for why NoNukes thought it should be summary time, it's because you don't even have a middle school level in physics and since this subject is heavily related to physics, it's useless to discuss it with you. The proof of it is the hundreds of messages we have spent trying to teach you high school level physics and you failing to understand anything.

This message is a reply to:
 Message 1163 by ICANT, posted 09-08-2011 4:43 AM ICANT has not replied

NoNukes
Inactive Member


Message 1165 of 1229 (632499)
09-08-2011 9:53 AM
Reply to: Message 1162 by ICANT
09-08-2011 4:35 AM


Re: Inertial reference frames ... again
ICANT writes:
Why do you think it is summary time?
It is summary time, at least for my participation, because I don't believe you are capable of understanding elementary physics and you have demonstrated to my satisfaction that you will never be capable. You aren't even trying.
The fact that measured quantities (such as paths of particles, kinetic energies, momenta) and are different for different inertial observers was demonstrated 300 years ago. It is not a subject for debate. Yet that's exactly what we've been doing for hundreds of messages.
I'm satisfied that you are the only one here that doesn't get it. I cannot tell whether your own failure to understand is out of ignorance or stubborness. It no longer matters.
As for your OP, you don't have to end the thread, but your thread was essentially dead before I made my first post.
I'll also note that this isn't your first thread on this subject and that you've gotten here essentially the same reaction that you got before.
As for this photon thought experiment...
ICANT writes:
My position is that if Einsteins two postulates and Newtons laws are correct the photon can not hit the detector in the car, unless an unbalanced force is applied to the photon
That's not quite all of it. You believe that when the car is enclosed, a mysterious force appears so that the photon does what Einstein actually predicts, but that when the car is open, that force disappears so that Einstein is wrong.
Your explanation for the force, is that enclosed frames are non-inertial frames of reference despite the fact that 1) calling a frame non-inertial does not make forces appear from nowhere and 2) enclosed frames moving at constant velocity, are by every definition either of us has produced, inertial frames of reference.
I see your silly drawings. But remember that you predict a different result when the car is open than when it is enclosed. Your explanation for the difference is pure malarkey born out of desperation.
So the track is traveling at constant speed of 1,818.028285941509 nanometers per second relative to the car.
ICANT, the above statement is just plain wrong. If the car is moving at 0.5c relative to the track, then the track is moving at 0.5c relative to the car. There is no other option. Do you understand what the word "relative" means?
There is simply no point in discussing special relativity with someone who does not know, and cannot understand, how non-relativistic physics works. I like discussing physics, but I don't need conversation badly enough to discuss it on an idiot level.
Edited by NoNukes, : Clean up

This message is a reply to:
 Message 1162 by ICANT, posted 09-08-2011 4:35 AM ICANT has not replied

NoNukes
Inactive Member


Message 1166 of 1229 (632500)
09-08-2011 9:59 AM
Reply to: Message 1163 by ICANT
09-08-2011 4:43 AM


Re: Inertial reference frames ... again
The car is not stationary. You can say it is at rest but you can't say it is stationary.
There is nothing wrong with using the word stationary. In fact, Einstein in his 1905 paper referred to inertial reference frames as stationary frames.
Edited by NoNukes, : Remove stuff that Son already covered.

This message is a reply to:
 Message 1163 by ICANT, posted 09-08-2011 4:43 AM ICANT has replied

Replies to this message:
 Message 1176 by ICANT, posted 09-08-2011 12:40 PM NoNukes has replied

Stile
Member (Idle past 130 days)
Posts: 4295
From: Ontario, Canada
Joined: 12-02-2004


(1)
Message 1167 of 1229 (632503)
09-08-2011 10:43 AM
Reply to: Message 1162 by ICANT
09-08-2011 4:35 AM


What about a balloon?
Let's try a simpler scenario to see if you can understand your error.
A) We have a car travelling on the Salt Lake Flats at a steady 100 km/h (no acceleration), it's got a sunroof. A guy inside the car has a balloon.
1. The sunroof is closed. He holds the balloon in front of his chest at arms length (above his knees). He lets go. The balloon drops as any balloon would (due to gravity) and gently hits his knees. Do you agree?
2. He opens the sunroof and holds the balloon outside the car. He lets go. The balloon gets whooshed away behind him and is left far behind. Do you agree?
B) We have a car travelling on the Salt Lake Flats at a steady 0.5c (no acceleration), it's got a sunroof. A guy inside the car has a balloon.
1. The sunroof is closed. He holds the balloon in front of his chest at arms length (above his knees). He lets go. The balloon drops as any balloon would (due to gravity) and gently hits his knees. Do you agree?
2. He opens the sunroof and holds the balloon outside the car. He lets go. The balloon gets whooshed away behind him and is left far behind, very, very quickly. Do you agree?
C) We have a car travelling in space, where there is no wind resistance or friction to consider, at a steady 100 km/h (no acceleration), it's got a sunroof. A guy inside the car has a balloon.
1. The sunroof is closed. He holds the balloon in front of his chest at arms length (above his knees). He lets go. This time, since there is no gravity where he is in space, the balloon just sits there, in front of him, exactly where he let it go... floating in mid-air. Do you agree?
2. He puts on a space-suit, opens the sunroof and holds the balloon outside the car. He lets go. This time, the balloon just sits there, directly above the car, exactly where he let it go... floating in mid-space. Travelling along with the car at exactly 100 km/h. Do you agree?
D) We have a car travelling in space, where there is no wind resistance or friction to consider, at a steady 0.5c (no acceleration), it's got a sunroof. A guy inside the car has a balloon.
1. The sunroof is closed. He holds the balloon in front of his chest at arms length (above his knees). He lets go. This time, since there is no gravity where he is in space, the balloon just sits there, in front of him, exactly where he let it go... floating in mid-air. Do you agree?
2. He puts on a space-suit, opens the sunroof and holds the balloon outside the car. He lets go. This time, the balloon just sits there, directly above the car, exactly where he let it go... floating in mid-space. Travelling along with the car at exactly 0.5c. Do you agree?
I take it, from your responses in this thread, that you do agree with all of A) and B). However, you only agree with C)1. and D)1. and not C)2. and D)2.? I think this is your error. I assure you that these sorts of behaviours have been experimentally tested and verified many, many times. All the above situations I have explained are exactly what happens in the real world. If you do not agree, (especially with C)1. where the balloon is being let go in space at 100km/h and remains floating directly over the car) you have a fundamental flaw in your understanding of physics and that basic flaw needs to be corrected before moving on to things like near-light speed travel and photon activity.
If you could clarify your disagreement with these simpler examples, I'm sure the more physically-inclined here would be better able to tune their answers to where your physics knowledge needs to be improved.
Things like friction (wind resistance, gravity..) are very common on earth and affect our "common-sense" thinking of how physics work. They tend to blur the lines between the definitions of velocity and acceleration unless we explicitly understand exactly how everything is working together.
A car on the Salt Lake Flats travelling at a constant velocity of 100km/h requires continuous force (acceleration from gas to the engine) to overcome the external forces (like wind resistance) that are restricting it. That's why the inside of the car and the outside of the car react so differently.
However, when we move to outer space, velocity and acceleration are more distinct and we can clearly see how the two are different. In space, without external forces (wind resistance, gravity...) inside the car and outside the car are exactly the same. Once you're going 100km/h, if you take your foot off the gas pedal the car will not slow down as it would on Earth (assuming that in space, the gas pedal controls fuel to the rocket boosters or something). I think you're having trouble accepting this because you're so used to thinking of things as they react on Earth. If you could clarify where you're having issues... I'm sure we could clarify our answers. The simpler the scenario is where we can find a disagreement, the simpler the explanation will be in order to find a meeting of the minds.

This message is a reply to:
 Message 1162 by ICANT, posted 09-08-2011 4:35 AM ICANT has replied

Replies to this message:
 Message 1174 by ICANT, posted 09-08-2011 12:39 PM Stile has replied

crashfrog
Member (Idle past 1553 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 1168 of 1229 (632504)
09-08-2011 10:46 AM
Reply to: Message 1163 by ICANT
09-08-2011 4:43 AM


Re: Inertial reference frames ... again
The car is not stationary. You can say it is at rest but you can't say it is stationary.
We can certainly say that it is stationary relative to its own reference frame. Nothing is ever moving relative to itself.
The car is traveling at a constant speed of 0.5 c relative to the tracks.
Sure, but it has zero velocity relative to itself. Further, since it has constant speed it is being acted on by no forces. Since no forces are acting on the light beam either, we know that the light beam will hit the detector, because in that frame of reference the only thing with motion is the light beam and we know what direction it is pointed. Relative to the emitter, the car will not move any distance whatsoever.
Everything is moving relative to something.
Except to itself.

This message is a reply to:
 Message 1163 by ICANT, posted 09-08-2011 4:43 AM ICANT has replied

Replies to this message:
 Message 1171 by ICANT, posted 09-08-2011 12:12 PM crashfrog has not replied

crashfrog
Member (Idle past 1553 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 1169 of 1229 (632506)
09-08-2011 10:47 AM
Reply to: Message 1162 by ICANT
09-08-2011 4:35 AM


Re: Inertial reference frames ... again
If the photon hits the last D the photon has to move two feet in the direction the car is traveling relative to the point the photon is emitted.
No, because the "point at which the photon was emitted" is also in motion, along with the car.

This message is a reply to:
 Message 1162 by ICANT, posted 09-08-2011 4:35 AM ICANT has replied

Replies to this message:
 Message 1172 by ICANT, posted 09-08-2011 12:17 PM crashfrog has replied

Taq
Member
Posts: 10158
Joined: 03-06-2009
Member Rating: 4.4


Message 1170 of 1229 (632512)
09-08-2011 11:11 AM
Reply to: Message 1163 by ICANT
09-08-2011 4:43 AM


Re: Inertial reference frames ... again
The car is not stationary.
With respect to the driver and pen laser, yes it is.
The car is traveling at a constant speed of 0.5 c relative to the tracks.
The car is not moving relative to the driver and pen laser. The car is stationary in the driver's inertial frame. However, the tracks are not stationary in the driver's inertial frame.
You have done nothing to show that my diagram in message 1092 is incorrect. Therefore, that diagram stands. The photon strikes the second sensor.

This message is a reply to:
 Message 1163 by ICANT, posted 09-08-2011 4:43 AM ICANT has not replied

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