# The Naked Scientists Forum

### Author Topic: What time does the rocket arrive at point B?  (Read 6073 times)

#### Thebox

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##### What time does the rocket arrive at point B?
« on: 15/08/2016 09:26:50 »
A Rocket leaves point (A) at travelling at c and 12am emitting a light beam onto point (A) travelling to point (B) expanding the length of the beam, the rocket takes 8 minutes to arrive at point (B), what time is the rocket seen arriving at point (B)?
« Last Edit: 15/08/2016 09:30:45 by Thebox »

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #1 on: 19/08/2016 06:28:21 »
After a lengthy consideration with no replies, I get 12.08 regardless what ''you'' say because the very simple diagram shows this without uncertainty.

P.s this is not a new theory it is a query, I want to accept the present version and move on, but I can't move on without questioning what I feel is an inaccuracy.

I have a problem because of this -

A length of free space=X

x= 299 792 458 m

A Photon travels back and forth along X,

This ''clock'' is constant .

+vx=c=1s

-vx=c=1s

difference t=0

The only possible thing that can slow this ''clock'' down is if we add permeability.

added- I removed all 4 dimensional reference points, leaving the 1 dimensional whole of free space. (the 5th dimension and ''stationary'' reference frame of ''invisible'').

added- also my problem is this

If you ''stood'' at one end of X and I ''stood'' the other, and we simultaneously turn on our flashlights, we see each other at the same time, using the same above calculation.

added- also there is the problem of that I can see the entire clear distance of free space between objects and can ''see'' that ''invisible'' photons occupy this space that are not in my eyes. i.e 1ft away from my eyes I clearly observe there is Photons in this free space, I can clearly distinguish shadow at a distance where there is less Photons/light. I clearly observe this very writing of ''darkness'' the absence of photons in its exact geometrical position.
From this writing to my eyes I observe the free space is ''full'' of invisible Photons that have not entered my eyes. I observe spectral content 400nm-700nm seemingly in its exact location relative to free space.  I observe free space to be stationary because we cant observe things that are invisible to have motion although it is apparent that the invisible is in motion.

added- and need I remind you https://en.wikipedia.org/wiki/Metre

« Last Edit: 19/08/2016 07:56:50 by Thebox »

#### phyti

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##### Re: What time does the rocket arrive at point B?
« Reply #2 on: 19/08/2016 19:47:16 »
Perhaps no one replies because they have debated this scenario before without any constructive results.
The time of arrival has different answers, depending on which event and which clock.
With A and B clocks synchronized,
A sees (the image of) rocket arrival at 12:16. In the image the B clock reads 12:08.
B sees rocket arrival at 12:08.
The rocket clock reads 12:00 at arrival.

If the rocket made a return trip to A, would the clocks unwind to make the time=0?

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #3 on: 19/08/2016 21:54:49 »

A sees (the image of) rocket arrival at 12:16. In the image the B clock reads 12:08.

This bit is wrong but nobody is listening to me when I am showing why it is wrong. They expect me to accept this when it is wrong.

It is enough to drive me insane and it is so simple why it is wrong but nobody seems to understand and keep replying with 12:16 when it is 12:08.

Lets us take this in really short steps, it may takes several days.

Let us have point A

A rocket is ''stationary'' at point (A). Velocity=0

You are an observer in the control tower, you can see the rocket.

Photons reflect off the rocket and travel distance X to your eyes , do you agree with this?

#### Colin2B

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##### Re: What time does the rocket arrive at point B?
« Reply #4 on: 20/08/2016 04:20:51 »

A sees (the image of) rocket arrival at 12:16. In the image the B clock reads 12:08.

This bit is wrong but nobody is listening to me when I am showing why it is wrong. They expect me to accept this when it is wrong.

It is enough to drive me insane and it is so simple why it is wrong but nobody seems to understand and keep replying with 12:16 when it is 12:08.
No, it is not wrong and any attempt to prove otherwise is a new theory - or more properly an 'it can't be true'

Lets us take this in really short steps, it may takes several days.
Let's not. To do so would insult the intelligence of most primary school children.

One last try on a subject we have been over many times.
Let the rocket send out a flash of light every minute.
It leaves at 1200 and sends its first flash at 1201 which takes another 1min to travel back to A arriving at 1202.
Similarly the flash at 1202 arrives at A 1204
1203 at 1206
1204 at 1208
1205 at 1210
1206 at 1212
1207 at 1214
Finally at 1208 the rocket arrives at B and emits final flash, this flash along with the light reflected from the rocket (its image) arrives at A at 1216.

Whether you accept reality or not, this is the way it works. Live with it.

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #5 on: 20/08/2016 08:08:31 »

A sees (the image of) rocket arrival at 12:16. In the image the B clock reads 12:08.

This bit is wrong but nobody is listening to me when I am showing why it is wrong. They expect me to accept this when it is wrong.

It is enough to drive me insane and it is so simple why it is wrong but nobody seems to understand and keep replying with 12:16 when it is 12:08.
No, it is not wrong and any attempt to prove otherwise is a new theory - or more properly an 'it can't be true'

Lets us take this in really short steps, it may takes several days.
Let's not. To do so would insult the intelligence of most primary school children.

One last try on a subject we have been over many times.
Let the rocket send out a flash of light every minute.
It leaves at 1200 and sends its first flash at 1201 which takes another 1min to travel back to A arriving at 1202.
Similarly the flash at 1202 arrives at A 1204
1203 at 1206
1204 at 1208
1205 at 1210
1206 at 1212
1207 at 1214
Finally at 1208 the rocket arrives at B and emits final flash, this flash along with the light reflected from the rocket (its image) arrives at A at 1216.

Whether you accept reality or not, this is the way it works. Live with it.

NO, I will not accept that and live with that because it is in error and none of you are objective enough to actually listen. It is not a new theory and neither is it a can't be true.  It is the student questioning what you are teaching him. Would you really want a student to be taught incorrectly and accept false information?

I am telling you it is wrong, I can show why it is wrong yet you all keep insisting it is correct when it clearly is not.

I tell you what Colin, discuss what I have said, if I don't show I am correct, then I will leave the forum forever.

That is how sure I am the information you are telling me is at fault.

Let us have point A

A rocket is ''stationary'' at point (A). Velocity=0

You are an observer in the control tower, you can see the rocket.

Photons reflect off the rocket and travel distance X to your eyes , do you agree with this?

Let us have point A, at point A is a stationary rocket, velocity=0

Captain Stewart sits in the cockpit looking towards the tower (point B) where he can see you.

Photons reflect off you travelling distance X to Captain Stewart's eyes , do you agree with this?

let us say distance X = 1 light second

from A to B the light takes 1 light second to reach the tower

from B to A the light takes 1 light second to reach Captain Stewart, do you agree with this?

Lets us be in a night time situation, the Sun rises at 6 am, at 6.08 am the first Photons of the day reflect off A and B at the same time.

photon (A) travels to (B) while simultaneously photon (B) travels to (A)

The tower (point B) and Captain Stewart (point A) both simultaneously receive their first sight of each other at 6.08 and 1 light second.

Do you agree with this?

« Last Edit: 20/08/2016 09:05:26 by Thebox »

#### evan_au

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##### Re: What time does the rocket arrive at point B?
« Reply #6 on: 21/08/2016 05:29:41 »
Quote from: TheBox
vx=c=1s
This bit of pseudo-mathematical mash is confused because the author has not tried to compare the units (in which case he would have seen that it is wrong, although perhaps not realized why).
- You can't say  "c=1s", because the units of c are meters per second (a velocity), while the units of 1 second are time. If the units don't match on each side of the "=", the numbers are nonsense.
- "vx=c", is even more confusing because I could not see "v" defined anywhere. Assuming the normal convention that v is a velocity, the units of v are meters per second (like c), and the units of x are meters. The units on the left are seconds which don't match the meters per second on the right side of the "=" (although it does match the seconds on the last "="). If the units don't match, the numbers are nonsense.

You calculate the propagation time t (in seconds) as velocity v (in meters per second) x distance (in meters).
Because we are talking about light pulses in a vacuum, the velocity = c (in meters per second).

Corrected:
t = x/v = x/c = 1 second
Units: Time = (meters)/(meters per second) = (seconds)

Quote from: TheBox
+vx=c=1s

-vx=c=1s

difference t=0
Reading between the lines, this seems to be saying that light takes 1 second to propagate in one direction and that light takes -1 second to propagate in the opposite direction, for a round-trip time of zero seconds. If you achieve this, you will win a Nobel Prize; unfortunately, it is a fallacy.

The next bit of confusion seems to be around "+"/"-". This seems to be using velocity or distance as a vector; vectors can have a direction, which can be "+", "-" depending on how you are using it. Just like using units consistently is essential, it is essential to use the direction of a vector consistently, or the equation is a nonsense.

If you have never studied vectors at university level, I suggest you just stick to scalars.

It takes 1 second for the light to travel in one direction, and it takes another second for the light to travel in the other direction, for a round-trip time of 2 seconds. Definitely not 0 seconds!

Note: I might have misread these equations; if so, please explain what was intended.

Correction: I tried to analyse the units, and mangled it badly - apologies
« Last Edit: 21/08/2016 22:27:06 by evan_au »

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #7 on: 21/08/2016 07:56:39 »
Quote from: TheBox
vx=c=1s
This bit of pseudo-mathematical mash is confused because the author has not tried to compare the units (in which case he would have seen that it is wrong, although perhaps not realized why).
- You can't say  "c=1s", because the units of c are meters per second (a velocity), while the units of 1 second are time. If the units don't match on each side of the "=", the numbers are nonsense.
- "vx=c", is even more confusing because I could not see "v" defined anywhere. Assuming the normal convention that v is a velocity, the units of v are meters per second (like c), and the units of x are meters. The units on the left are seconds which don't match the meters per second on the right side of the "=" (although it does match the seconds on the last "="). If the units don't match, the numbers are nonsense.

You calculate the propagation time t (in seconds) as velocity v (in meters per second) x distance (in meters).
Because we are talking about light pulses in a vacuum, the velocity = c (in meters per second).

t = v*x = c*x = 1 second
Units: Time = (meters per second) * (meters) = (seconds)

Quote from: TheBox
+vx=c=1s

-vx=c=1s

difference t=0
Reading between the lines, this seems to be saying that light takes 1 second to propagate in one direction and that light takes -1 second to propagate in the opposite direction, for a round-trip time of zero seconds. If you achieve this, you will win a Nobel Prize; unfortunately, it is a fallacy.

The next bit of confusion seems to be around "+"/"-". This seems to be using velocity or distance as a vector; vectors can have a direction, which can be "+", "-" depending on how you are using it. Just like using units consistently is essential, it is essential to use the direction of a vector consistently, or the equation is a nonsense.

If you have never studied vectors at university level, I suggest you just stick to scalars.

It takes 1 second for the light to travel in one direction, and it takes another second for the light to travel in the other direction, for a round-trip time of 2 seconds. Definitely not 0 seconds!

Note: I might have misread these equations; if so, please explain what was intended.

Can you remember the time we did

-ve and +ve ?

I thought v in this instant was vector and e was just any direction?

So i put vx representing vector x.

vx=c

c representing the speed of light

and 1 second for the time it take light to travel vx.

vx=c=1.s

Well anyway , the reason you have not  understood because you have misinterpreted the 0 .

It is sight related and my diagram and explanation is very correct.

A photon takes 8 minutes to arrive at (B)

A second photon simultaneously also takes 8 minutes to reach (A)

Between A and B is 1 light second of travel for the light.

The observers A and B see each other at the exact same time.

The Photon leaves the sun at 6am
it arrives at 6.08am
it is reflected at 6.08am
it travels 1 second and is received by Captain Stewart's eyes at 6.08am and 1 light second

The second Photon is exactly the same that enters your eyes from  the reflection off the rocket. You see captain Stewart simultaneously.

The last diagram I did simply shows this to be true.

added- not a round trip, individual trips, a=+ve  b=+ve

« Last Edit: 21/08/2016 08:49:02 by Thebox »

#### Colin2B

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##### Re: What time does the rocket arrive at point B?
« Reply #8 on: 21/08/2016 08:47:33 »
Can you remember the time we did

-ve and +ve ?

I thought v in this instant was vector and e was just any direction?
-ve and +ve are abbreviations for the words negative and positive

The Photon leaves the sun at 6am
it arrives at 6.08am
it is reflected at 6.08am
it travels 1 second and is received by Captain Stewart's eyes at 6.08am and 1 light second

The second Photon is exactly the same that enters your eyes from  the reflection off the rocket. You see captain Stewart simultaneously.
This is not the same question/situation as the original one. Let's deal with one question at a time.
In the original question it doesn't matter how long it takes for the light to travel from the sun, just how long it takes for light reflected from the rocket - when it arrives at B - to travel back to A.
The question is "at what time does that light reach A", answer 1216.

PS there is of course an interesting twist to this. Because the rocket travels at the (impossible) speed of light, the light from its take off arrives at B at the same time as the rocket's arrival, so people at B see the take off and arrival simultaneously!

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #9 on: 21/08/2016 08:57:58 »

-ve and +ve are abbreviations for the words negative and positive

Yes direction, I was using them from switching ''view'' from each observer, I place myself in each position to ''see'' what I see.

If I am in position A relative to me the Photon leaving B is travelling -ve but relative to B the Photon is travelling +ve and vice versus for the Photon leaving A.

Quote
This is not the same question/situation as the original one.

I assure you Colin it is the same question but the answer is a lot harder to ''see'' and visualise. I  have now managed to simplify from the original explanation, I have been explaining this for years but now I have finally got a really simple version.

The very first time I was told we see the sun in its past, alarm bells rang in my head. When I realised ''you'' was only accounting for a one way journey I realised there was an incompleteness.

If the Earth ''see's'' the Sun 8 minutes ago

and the Sun ''see's'' the Earth 8 minutes ago

then they both see each other 8 minutes ago

which cancels each other out and means they ''see'' each other now.

added- I am not trying to ''break'' science , I am learning it.  When I learn something I like to try and visualise and even sometimes doodle a diagram of the information to help  me interpret the information.

We see the sun 8 minutes ago, yes if considering a point source(photon)  travelling from the sun into our eyes .

I can draw a straight line vector from A to B

This is all good and sound logic.

However if I add a second observer to the scenario and consider the Photons reflected from both observers that allows them to observe each other, there adds complication and something is seemingly contradiction to the initial statement of we observe the Sun in its past.

I have considered it does not matter is we displaced the two observers e.g one closer to the source, because a linearity remains between the two observers and the simultaneous event of reflection travel time from either body remains equal no matter what the distance because the very fact light is constant in free space.

« Last Edit: 21/08/2016 10:10:07 by Thebox »

#### jeffreyH

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##### Re: What time does the rocket arrive at point B?
« Reply #10 on: 21/08/2016 10:51:16 »
Let's not all get boxed in (metres per second) times (metres) is metres squared per second. One way to get t is v/a. That is velocity divided by acceleration.

#### Colin2B

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##### Re: What time does the rocket arrive at point B?
« Reply #11 on: 21/08/2016 18:09:29 »
please tell me if this incorrect logic

If the Earth ''see's'' the Sun 8 minutes ago = correct

and the Sun ''see's'' the Earth 8 minutes ago = correct

then they both see each other 8 minutes ago = correct

which cancels each other out and means they ''see'' each other now. = incorrect,
there is nothing to cancel out. They both see each other as they were 8 mins ago, not as they are now.

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #12 on: 21/08/2016 18:45:22 »

If the Earth ''see's'' the Sun 8 minutes ago = correct

and the Sun ''see's'' the Earth 8 minutes ago = correct

then they both see each other 8 minutes ago = correct

which cancels each other out and means they ''see'' each other now. = incorrect,
there is nothing to cancel out. They both see each other as they were 8 mins ago, not as they are now.

They both see each other 8 minutes ago, ok let us think this through.

You are saying we both see each other in the  past, so I exist now but I see the Sun in its past , the Sun exists now but it ''see's'' me in the past.

I am sorry that makes no sense,

do you agree we both see each other simultaneously as my diagram shows?

If not what do you contest?

#### PhysBang

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##### Re: What time does the rocket arrive at point B?
« Reply #13 on: 21/08/2016 20:07:33 »

A sees (the image of) rocket arrival at 12:16. In the image the B clock reads 12:08.

This bit is wrong but nobody is listening to me when I am showing why it is wrong. They expect me to accept this when it is wrong.
I think that few people expect you to accept the correct answer. You have amply demonstrated to most people that you are incapable of understanding at least this topic. This may be due to a number of factors. I highly recommend that you seek some form of counseling to consider whether or not everyone else in the world has the problem or if just you has the problem here.

#### Colin2B

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##### Re: What time does the rocket arrive at point B?
« Reply #14 on: 21/08/2016 20:13:17 »
Reread what I said in my last post "They both see each other as they were 8 mins ago, not as they are now"

I will spell it out:

2 people are 8 light minutes apart. At exactly 1200 they both wave their arms once. The light from these events travels to the 2 people and at 1208 they both see the other wave their arms even though they have not waved their arms for the last 8 minutes. They are seeing now (1208) what happened in the past (1200).

We have been over this in a number of different threads and you obviously find the concept difficult to understand, so we had best leave it at that if you really don't understand what I have said.

Edit: I notice PhysBang replied while I was typing. I agree with him, I don't think you will ever accept the correct answer so further discussion is futile. I certainly don't have time to waste on something which is so obvious.

« Last Edit: 21/08/2016 20:17:03 by Colin2B »

#### pzkpfw

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##### Re: What time does the rocket arrive at point B?
« Reply #15 on: 21/08/2016 21:17:04 »
They both see each other 8 minutes ago, ok let us think this through.

You are saying we both see each other in the  past, so I exist now but I see the Sun in its past , the Sun exists now but it ''see's'' me in the past.

I am sorry that makes no sense,

do you agree we both see each other simultaneously as my diagram shows?

If not what do you contest?

Are you happier with the speed of sound?

Let's say you and a friend are on the Olympic (see, topical!) 100m track at opposite ends. Someone at the 50m mark (exactly between you) raises their hand. When you and your friend see that raised hand you both shout very loudly.

Excluding wind, temperature etc, you and your friend will hear each other at the "same time". But ... clearly, due to the speed of sound, you'll be hearing each other some time after you each shouted.

In your style, that means you are hearing each other in the "past". (From about 0.29 seconds ago).

Is that any kind of problem?

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #16 on: 21/08/2016 21:56:42 »

2 people are 8 light minutes apart. At exactly 1200 they both wave their arms once. The light from these events travels to the 2 people and at 1208 they both see the other wave their arms even though they have not waved their arms for the last 8 minutes. They are seeing now (1208) what happened in the past (1200).

, if you see me at 12.08 and I see you at 12.08 , we are seeing each other at the same time.

« Last Edit: 21/08/2016 22:14:00 by Thebox »

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #17 on: 21/08/2016 21:59:12 »
They both see each other 8 minutes ago, ok let us think this through.

You are saying we both see each other in the  past, so I exist now but I see the Sun in its past , the Sun exists now but it ''see's'' me in the past.

I am sorry that makes no sense,

do you agree we both see each other simultaneously as my diagram shows?

If not what do you contest?

Are you happier with the speed of sound?

Let's say you and a friend are on the Olympic (see, topical!) 100m track at opposite ends. Someone at the 50m mark (exactly between you) raises their hand. When you and your friend see that raised hand you both shout very loudly.

Excluding wind, temperature etc, you and your friend will hear each other at the "same time". But ... clearly, due to the speed of sound, you'll be hearing each other some time after you each shouted.

In your style, that means you are hearing each other in the "past". (From about 0.29 seconds ago).

Is that any kind of problem?

we are doing light not sound,

My diagram clearly shows it, can people not read diagrams?

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #18 on: 21/08/2016 22:00:22 »

A sees (the image of) rocket arrival at 12:16. In the image the B clock reads 12:08.

This bit is wrong but nobody is listening to me when I am showing why it is wrong. They expect me to accept this when it is wrong.
I think that few people expect you to accept the correct answer. You have amply demonstrated to most people that you are incapable of understanding at least this topic. This may be due to a number of factors. I highly recommend that you seek some form of counseling to consider whether or not everyone else in the world has the problem or if just you has the problem here.

My diagram is correct

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #19 on: 21/08/2016 22:11:43 »
Repeating back the present information is not going to answer my query of that information.

A and B see each other at the same time, simultaneously, is anyone saying they don't?

#### pzkpfw

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##### Re: What time does the rocket arrive at point B?
« Reply #20 on: 21/08/2016 22:16:40 »
Repeating back the present information is not going to answer my query of that information.

A and B see each other at the same time, simultaneously, is anyone saying they don't?

It's a little awkward that you keep changing the scenarios, but yes (assuming a few things), they each see each other from 6:08:00, at 6:08:01.

(This refers to your post #5).
« Last Edit: 21/08/2016 22:20:40 by pzkpfw »

#### pzkpfw

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##### Re: What time does the rocket arrive at point B?
« Reply #21 on: 21/08/2016 22:18:29 »
Are you happier with the speed of sound?

Let's say you and a friend are on the Olympic (see, topical!) 100m track at opposite ends. Someone at the 50m mark (exactly between you) raises their hand. When you and your friend see that raised hand you both shout very loudly.

Excluding wind, temperature etc, you and your friend will hear each other at the "same time". But ... clearly, due to the speed of sound, you'll be hearing each other some time after you each shouted.

In your style, that means you are hearing each other in the "past". (From about 0.29 seconds ago).

Is that any kind of problem?

we are doing light not sound,

My diagram clearly shows it, can people not read diagrams?

Nice evasion, are you afraid of the answer?

(I know that this is going to go down the path where you think light is different to sound, in that vison is "instant" once there's light between observer and object, but I think it's useful to the readers of this thread to see that in your words).

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #22 on: 21/08/2016 22:24:23 »
Are you happier with the speed of sound?

Let's say you and a friend are on the Olympic (see, topical!) 100m track at opposite ends. Someone at the 50m mark (exactly between you) raises their hand. When you and your friend see that raised hand you both shout very loudly.

Excluding wind, temperature etc, you and your friend will hear each other at the "same time". But ... clearly, due to the speed of sound, you'll be hearing each other some time after you each shouted.

In your style, that means you are hearing each other in the "past". (From about 0.29 seconds ago).

Is that any kind of problem?

we are doing light not sound,

My diagram clearly shows it, can people not read diagrams?

Nice evasion, are you afraid of the answer?

(I know that this is going to go down the path where you think light is different to sound, in that vison is "instant" once there's light between observer and object, but I think it's useful to the readers of this thread to see that in your words).

It is not evasion, my head is thinking of a Photon and not a wave that is all.  I understand already what  you are trying to explain and I could do a better job. However what you are explaining is not quite what I am explaining causes a contradiction to what I am trying to learn .

My earlier diagram shows I understand light travels and it takes 8 minutes to arrive giving the impression of we see the sun as it were 8 minutes ago.

However my contradiction shows simultaneous so I can not accept the learning without the issue been resolved.

« Last Edit: 21/08/2016 22:27:52 by Thebox »

#### Thebox

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##### Re: What time does the rocket arrive at point B?
« Reply #23 on: 21/08/2016 22:26:37 »
Repeating back the present information is not going to answer my query of that information.

A and B see each other at the same time, simultaneously, is anyone saying they don't?

It's a little awkward that you keep changing the scenarios, but yes (assuming a few things), they each see each other from 6:08:00, at 6:08:01.

(This refers to your post #5).

Yes exactly, they  both see each other at 6:08:01.    They see each other simultaneously do they not?

#### pzkpfw

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##### Re: What time does the rocket arrive at point B?
« Reply #24 on: 21/08/2016 22:37:12 »
Repeating back the present information is not going to answer my query of that information.

A and B see each other at the same time, simultaneously, is anyone saying they don't?

It's a little awkward that you keep changing the scenarios, but yes (assuming a few things), they each see each other from 6:08:00, at 6:08:01.

(This refers to your post #5).

Yes exactly, they  both see each other at 6:08:01.    They see each other simultaneously do they not?

I've already answered. What more do you want? (I'd guess you want a simpler less precise answer, so you can extract a "gotcha". I won't give you that).

Assuming a few things, such as A and B being at rest with respect to each other, then yes they will see each other at the "same time". But of course, because of the finite speed of light, they will be seeing each other as of a little time ago, in this case, they see each other at 6:08:01, but what they see, is each other as at 6:08:00.

Quite simple.

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##### Re: What time does the rocket arrive at point B?
« Reply #24 on: 21/08/2016 22:37:12 »