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# Existence

Author Topic:   Existence
ICANT
Member (Idle past 109 days)
Posts: 6769
From: SSC
Joined: 03-12-2007

 Message 1171 of 1229 (632525) 09-08-2011 12:12 PM Reply to: Message 1168 by crashfrog09-08-2011 10:46 AM

Re: Inertial reference frames ... again
Hi crash,
crashfrog writes:
Relative to the emitter, the car will not move any distance whatsoever.
True.
But relative to the photon the car will move 2 feet.
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 1168 by crashfrog, posted 09-08-2011 10:46 AM crashfrog has not replied

 Replies to this message: Message 1177 by Son, posted 09-08-2011 12:41 PM ICANT has not replied Message 1179 by NoNukes, posted 09-08-2011 12:57 PM ICANT has replied Message 1180 by Taq, posted 09-08-2011 1:07 PM ICANT has not replied

ICANT
Member (Idle past 109 days)
Posts: 6769
From: SSC
Joined: 03-12-2007

 Message 1172 of 1229 (632527) 09-08-2011 12:17 PM Reply to: Message 1169 by crashfrog09-08-2011 10:47 AM

Re: Inertial reference frames ... again
Hi crash,
crashfrog writes:
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.
How is the point at which the photon emitted in motion?
What force is exerted upon the point in the space of the car to cause the point to move.
The laser pen and the detector moves relative to that point.
The car moves relative to that point.
But the point does not move.
Now if you have some mechanism that can cause the point in space to move share it.
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 1169 by crashfrog, posted 09-08-2011 10:47 AM crashfrog has replied

 Replies to this message: Message 1173 by Son, posted 09-08-2011 12:34 PM ICANT has not replied Message 1175 by NoNukes, posted 09-08-2011 12:39 PM ICANT has replied Message 1178 by crashfrog, posted 09-08-2011 12:49 PM ICANT has not replied

Son
Member (Idle past 3912 days)
Posts: 346
From: France,Paris
Joined: 03-11-2009

 Message 1173 of 1229 (632531) 09-08-2011 12:34 PM Reply to: Message 1172 by ICANT09-08-2011 12:17 PM

Re: Inertial reference frames ... again
"Move" here is more of a way of talking, what he meant is that this point is at rest in the car's frame of reference. You still haven't looked at the illustrations provided by NoNukes it seems... You should do it, when you understand what is an inertial frame of reference, you will actually be able to understand what he says.
I admit though that the way he writes could cause further confusion to someone who doesn't understand the basics of physics.
Edited by Son, : No reason given.

 This message is a reply to: Message 1172 by ICANT, posted 09-08-2011 12:17 PM ICANT has not replied

ICANT
Member (Idle past 109 days)
Posts: 6769
From: SSC
Joined: 03-12-2007

 Message 1174 of 1229 (632532) 09-08-2011 12:39 PM Reply to: Message 1167 by Stile09-08-2011 10:43 AM

Re: What about a balloon?
Hi Stile,
Long time no communication.
Stile writes:
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.
But in the thought experiment the car on the Salt Lake Flats is traveling at 0.5 c relative to the tracks attached to the Salt Lake Flats.
This car is traveling in a vacuum. So it would be the same as outer space.
Stile writes:
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 don't have any problem with what a balloon might or might not do.
A balloon is not a photon traveling at c when it exits the emitter.
You as well as others here think that a photon will react the same as physical objects we are familiar with but the fact is it does not.
Eienstein's postulate #2 says:
quote:
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.
The last part of that statement says the light is independent of the state of motion of the emitting body.
So if the photon is emitted from the laser pen through your sunroof it will go in the direction at which the laser pen is pointed at the speed of c.
If it does not then Einstein was wrong.
Was Einstein wrong or will the photon go in a straight line from the point it was emitted?
Will the photon always remain above the car?
If it does what unbalanced force causes the photon to travel at 0.5 c horzontally while traveling at c vertically in the direction the laser pen was pointed from the point emitted from the laser pen?
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 1167 by Stile, posted 09-08-2011 10:43 AM Stile has replied

 Replies to this message: Message 1181 by Stile, posted 09-08-2011 1:11 PM ICANT has not replied Message 1182 by Taq, posted 09-08-2011 1:12 PM ICANT has not replied

NoNukes
Inactive Member

 Message 1175 of 1229 (632533) 09-08-2011 12:39 PM Reply to: Message 1172 by ICANT09-08-2011 12:17 PM

Re: Inertial reference frames ... again
How is the point at which the photon emitted in motion?
What force is exerted upon the point in the space of the car to cause the point to move.
I agree that the point at which the photon is emitted does not move. The point representing the emission of the photon is an event in space time having fixed space and time coordinates. The emission event has fixed coordinates in both the car and the track frame of reference.
But your question about the force is silly. Force does not make points in space time move.
The laser pen and the detector moves relative to that point.
The car moves relative to that point.
The above statement may or may not be true. If you want to be correct about whether something is at rest or moves, you need to communicate to which frame of reference is your observation applies.
In a frame of reference in which the car is at rest, the laser pen, detector do not move relative to the point at which the laser was emitted.

 This message is a reply to: Message 1172 by ICANT, posted 09-08-2011 12:17 PM ICANT has replied

 Replies to this message: Message 1183 by ICANT, posted 09-08-2011 1:14 PM NoNukes has replied

ICANT
Member (Idle past 109 days)
Posts: 6769
From: SSC
Joined: 03-12-2007

 Message 1176 of 1229 (632534) 09-08-2011 12:40 PM Reply to: Message 1166 by NoNukes09-08-2011 9:59 AM

Re: Inertial reference frames ... again
Hi NoNukes,
NoNukes writes:
There is nothing wrong with using the word stationary. In fact, Einstein in his 1905 paper referred to inertial reference frames as stationary frames.
"Stationary" relative to what?
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 1166 by NoNukes, posted 09-08-2011 9:59 AM NoNukes has replied

 Replies to this message: Message 1184 by NoNukes, posted 09-08-2011 1:18 PM ICANT has replied

Son
Member (Idle past 3912 days)
Posts: 346
From: France,Paris
Joined: 03-11-2009

 Message 1177 of 1229 (632535) 09-08-2011 12:41 PM Reply to: Message 1171 by ICANT09-08-2011 12:12 PM

Re: Inertial reference frames ... again
ICANT writes:
But relative to the photon the car will move 2 feet.
False even if we took for granted that the photon behaved the way you think it would. According to you, the photon would hit the sensor which would be 4.47 feet away from the car at this time, meaning the car would have traveled 4.47 feet away from the photon.
edit: here I'm writing using Newtonian physics since as long as you don't understand what an inertial frame is, there's no need to go further. That's why I didn't tell which frame I use for distances(since I didn't take into account length contraction).
Edited by Son, : No reason given.

 This message is a reply to: Message 1171 by ICANT, posted 09-08-2011 12:12 PM ICANT has not replied

crashfrog
Member (Idle past 1549 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003

 Message 1178 of 1229 (632538) 09-08-2011 12:49 PM Reply to: Message 1172 by ICANT09-08-2011 12:17 PM

Re: Inertial reference frames ... again
How is the point at which the photon emitted in motion?
Because it is a point in a moving reference frame. Since the coordinate system is in motion, and since the definition of the location of a "point" is relative to a coordinate origin, the point is in motion.
If I draw a point at 2,3 on a piece of graph paper, and then I pick up the paper and carry it across the room, I've defined a moving coordinate system and everything at rest in that system shares it's velocity. The point is in motion throughout the room.
Now if you have some mechanism that can cause the point in space to move share it.
The "mechanism" is the moving coordinate system, in which the point has been defined.

 This message is a reply to: Message 1172 by ICANT, posted 09-08-2011 12:17 PM ICANT has not replied

NoNukes
Inactive Member

 Message 1179 of 1229 (632542) 09-08-2011 12:57 PM Reply to: Message 1171 by ICANT09-08-2011 12:12 PM

Re: Inertial reference frames ... again
But relative to the photon the car will move 2 feet.
There is no possible way to interpret this statement so that it can be accurate. The blackboard, which is fixed to the inside of the car, is at least four feet from the laser pen. So unless the board is moving towards the laser pen, and it does not do so in any frame of reference, then the photon must travel at least four feet to hit the blackboard.
Possible correct answers (ignoring special relativity):
The photon moves 4 feet towards the blackboard (and relative to the car, or in the car frame of reference)
The photon moves 4 feet towards the blackboard while moving two feet in the direction along the tracks as measured in the track frame of reference.
Do you understand yet why I say that discussing physics with you is pointless?
Or if you insist on trying to use a photon frame of reference to do physics, you might say that no time passes within the photon frame and that the distance to the blackboard is length contracted to zero. But that would be fairly useless in analyzing the situation wouldn't it.
Given all of the possible correct ways to describe the situation, you, ICANT manage to blow it. Just what manner of man are you?

 This message is a reply to: Message 1171 by ICANT, posted 09-08-2011 12:12 PM ICANT has replied

 Replies to this message: Message 1185 by ICANT, posted 09-08-2011 1:30 PM NoNukes has replied

Taq
Member
Posts: 10158
Joined: 03-06-2009
Member Rating: 4.7

 Message 1180 of 1229 (632544) 09-08-2011 1:07 PM Reply to: Message 1171 by ICANT09-08-2011 12:12 PM

Re: Inertial reference frames ... again
But relative to the photon the car will move 2 feet.
No, it won't.

 This message is a reply to: Message 1171 by ICANT, posted 09-08-2011 12:12 PM ICANT has not replied

Stile
Member (Idle past 125 days)
Posts: 4295
Joined: 12-02-2004

 Message 1181 of 1229 (632548) 09-08-2011 1:11 PM Reply to: Message 1174 by ICANT09-08-2011 12:39 PM

Re: What about a balloon?
ICANT writes:
Hi Stile,
Long time no communication.
Yes, I've been... in and out of town.
I don't have any problem with what a balloon might or might not do.
Does that mean you agree with all the above scenarios? This will be helpful to your understanding... if you're interested in understanding. Just let me know if you have an issue with any of the balloon scenarios. I will be happy to go through things with you until we both understand what's going on, if you'd like.
A balloon is not a photon traveling at c when it exits the emitter.
You are correct. However, the portion of the photon-exiting-the-emitter scenario that you're getting wrong has nothing to do with the difference between regular objects (like balloons travelling at 100km/h) and photons . If you can understand what happens to the balloon, then you will understand what happens to the photon. This is why the balloon example is meaningful.
However, let's forget about balloons, if you'd like, and focus on the quote you keep bringing up.
ICANT writes:
Eienstein's postulate #2 says:
quote:
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.
I'm going to focus on the part I bolded.
Scenario 1
The car and apparatus on top is not moving at all through space.
The photon is emitted.
The photon hits the target, dead centre.
Scenario 2
The car and apparatus on top are moving at 0.5c through space.
The photon is emitted.
Stile says: The photon hits the target, dead centre.
ICANT says: The photon does not hit the target dead centre. All of a sudden the photon's propagation takes it somewhere behind dead centre.
All we've changed in the scenario is the "state of motion of the emitting body" (in Scenario 1 the emitting body is not moving and in Scenario 2 the emitting body has a motion of 0.5c through space).
But the Second postulate that you've quoted says this shouldn't change anything about the photon... the photon is propagated independent of the state of motion of the emitting body.
You keep quoting the Second postulate... but you keep demanding that the photon misses the target. It doesn't seem to add up.
My answer stays the same. My answer takes into acount that the photon's propagation is independent of the state of motion of the emitting body.
Your answer changes... and then you quote a postulate that your answer directly refutes? I don't understand your thought process.
If you are interested in understanding this level of physics, I advise you to ask questions about the balloon scenarios I described. They will be much easier to grasp and transfer that understanding to the propagation of photons.

 This message is a reply to: Message 1174 by ICANT, posted 09-08-2011 12:39 PM ICANT has not replied

Taq
Member
Posts: 10158
Joined: 03-06-2009
Member Rating: 4.7

 Message 1182 of 1229 (632549) 09-08-2011 1:12 PM Reply to: Message 1174 by ICANT09-08-2011 12:39 PM

Re: What about a balloon?
The last part of that statement says the light is independent of the state of motion of the emitting body.
It says that the VELOCITY of light is independent of the state of motion of the emitting body. The motion of the emitting body will affect the path of the light as measured by different observers. However, all observers will observe that light travels at c along that path.
Was Einstein wrong or will the photon go in a straight line from the point it was emitted?
Of course it will go in a straight line, but different observers will observe different angles for the path of the photon as it travels in a straight line. However, all observers will see that the photon is travelling at 3E8 m/s.

 This message is a reply to: Message 1174 by ICANT, posted 09-08-2011 12:39 PM ICANT has not replied

ICANT
Member (Idle past 109 days)
Posts: 6769
From: SSC
Joined: 03-12-2007

 Message 1183 of 1229 (632550) 09-08-2011 1:14 PM Reply to: Message 1175 by NoNukes09-08-2011 12:39 PM

Re: Inertial reference frames ... again
Hi NoNukes,
NoNukes writes:
I agree that the point at which the photon is emitted does not move. The point representing the emission of the photon is an event in space time having fixed space and time coordinates. The emission event has fixed coordinates in both the car and the track frame of reference.
Thanks for the agreement I was beginning to believe you was right and I did not know what my Chief Architect program showed me when I drew straight lines.
NoNukes writes:
But your question about the force is silly. Force does not make points in space time move.
My point exactly.
Now if Einstein was correct when he proposed postulate #2 which says:
quote:
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.
If the photon emitted at that point in space goes in a straight line from that point in the direction the laser pen is pointed it can not hit a detector that has moved 2 feet relative to that point in space, unless some unbalanced force is applied to the photon.
I am sure you will disagree as it seems when you entered the classroom to study you checked your mind at the door.
You seem to have a sharp brilliant mind, so use it to think with.
NoNukes writes:
The laser pen and the detector moves relative to that point.
The car moves relative to that point.
The above statement may or may not be true. If you want to be correct about whether something is at rest or moves, you need to communicate to which frame of reference is your observation applies.
What part of relative to that point do you not understand?
Doesn't that mean I am refering to the frame in which the point exists?
Reference frames overlap all over the universe.
NoNukes writes:
In a frame of reference in which the car is at rest,
Is the car moving at a constant speed of 0.5 c while declared to be at rest?
NoNukes writes:
the laser pen, detector do not move relative to the point at which the laser was emitted.
Doesn't that mean that the point then is moving in the direction the car is moving at a constant speed of 0.5 c at 0.5 c?
But you said that point could not move.
Which is it?
Does it move or not? Please clarify.
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 1175 by NoNukes, posted 09-08-2011 12:39 PM NoNukes has replied

 Replies to this message: Message 1186 by NoNukes, posted 09-08-2011 1:56 PM ICANT has not replied Message 1188 by NoNukes, posted 09-08-2011 2:21 PM ICANT has replied

NoNukes
Inactive Member

 Message 1184 of 1229 (632551) 09-08-2011 1:18 PM Reply to: Message 1176 by ICANT09-08-2011 12:40 PM

Re: Inertial reference frames ... again
ICANT writes:
NoNukes writes:
There is nothing wrong with using the word stationary. In fact, Einstein in his 1905 paper referred to inertial reference frames as stationary frames.
"Stationary" relative to what?
All inertial reference frames are stationary frames. That should not be the least bit confusing. Choosing a reference frame determines which objects under discussion are stationary.
Have you ever used the word stationary? What did you mean when you used the word, osmium-like one?

 This message is a reply to: Message 1176 by ICANT, posted 09-08-2011 12:40 PM ICANT has replied

 Replies to this message: Message 1189 by ICANT, posted 09-08-2011 2:30 PM NoNukes has replied

ICANT
Member (Idle past 109 days)
Posts: 6769
From: SSC
Joined: 03-12-2007

 Message 1185 of 1229 (632554) 09-08-2011 1:30 PM Reply to: Message 1179 by NoNukes09-08-2011 12:57 PM

Re: Inertial reference frames ... again
Hi NoNukes,
NoNukes writes:
Do you understand yet why I say that discussing physics with you is pointless?
Sure I understand.
You checked your mind when you entered the classroom and never picked it up when you left the classroom.
NoNukes writes:
The photon moves 4 feet towards the blackboard while moving two feet in the direction along the tracks as measured in the track frame of reference.
What causes the photon to move 2 feet relative to the motion of the car along the tracks.
To do so declares that postulate #2 is false.
Postulate #2 says:
quote:
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.
The photon has to travel independent of the state of the motion of the laser pen which is attached to the car as is the blackboard.
There is no way the statement "independent of the state of motion of the emitting body" can be true if the photon does not go in a straight line from the point emitted across the car and miss the blackboard.
Because relative to the point coordinates in space the photon was emitted the blackboard has moved 2 feet.
You are on record as saying the point in space where the photon was emitted can not move.
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 1179 by NoNukes, posted 09-08-2011 12:57 PM NoNukes has replied

 Replies to this message: Message 1187 by NoNukes, posted 09-08-2011 2:08 PM ICANT has not replied Message 1190 by Taq, posted 09-08-2011 2:33 PM ICANT has replied Message 1206 by crashfrog, posted 09-08-2011 7:00 PM ICANT has not replied

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