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Author Topic: Do we see the Sun where it was 8.3 minutes ago?  (Read 4303 times)

Offline Phractality

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Do we see the Sun where it was 8.3 minutes ago?
« on: 23/12/2015 17:58:02 »
For years, I've accepted Tom Van Flandern's proof, and others like it, that gravity is billions of times faster than light. That proof is based  on the claim that we see the sun where it was, not where it is. I am now having second thoughts.

Of course the Sun is where it was 8 minutes ago, in Solar coordinates. I'm referring to the direction relative to the stars, which goes thru 360 degrees in a year. In 8.3 minutes, the direction of the Sun from Earth changes by .0057. So do we see the light coming from .0057 east of its current location? If we were moving in a straight line past the Sun, I believe that would be the case.

I have read that a term in general relativity almost exactly cancels the direction change of the light, as if the centers of successive light pulses follow the source.

The direction where we see an expanding spherical shell of light is perpendicular to the surface of the shell as it passes us. If we were in a circular orbit, I think the change in our direction, relative to the stars, would put the Sun's image back where the Sun is. I wonder if this analogy corresponds to the mysterious term in GR.

Our orbit is elliptical, and if I'm right, the angle between where we see the Sun and where it is ought to go thru an annual cycle. Concentric light spheres spreading from the Sun are always tangent to a circular orbit, but only tangent to an elliptical orbit at aphelion and perihelion.

If I now discard the idea that gravity is billions of times faster than light, there will need to be some changes in my model. I still think gravity is faster than light, but I'll have to look for a different proof and a different estimate of cg/cl.


 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #1 on: 23/12/2015 20:14:06 »
For years, I've accepted Tom Van Flandern's proof, and others like it, that gravity is billions of times faster than light. That proof is based  on the claim that we see the sun where it was, not where it is. I am now having second thoughts.

Of course the Sun is where it was 8 minutes ago, in Solar coordinates. I'm referring to the direction relative to the stars, which goes thru 360 degrees in a year. In 8.3 minutes, the direction of the Sun from Earth changes by .0057. So do we see the light coming from .0057 east of its current location? If we were moving in a straight line past the Sun, I believe that would be the case.

I have read that a term in general relativity almost exactly cancels the direction change of the light, as if the centers of successive light pulses follow the source.

The direction where we see an expanding spherical shell of light is perpendicular to the surface of the shell as it passes us. If we were in a circular orbit, I think the change in our direction, relative to the stars, would put the Sun's image back where the Sun is. I wonder if this analogy corresponds to the mysterious term in GR.

Our orbit is elliptical, and if I'm right, the angle between where we see the Sun and where it is ought to go thru an annual cycle. Concentric light spheres spreading from the Sun are always tangent to a circular orbit, but only tangent to an elliptical orbit at aphelion and perihelion.

If I now discard the idea that gravity is billions of times faster than light, there will need to be some changes in my model. I still think gravity is faster than light, but I'll have to look for a different proof and a different estimate of cg/cl.


Demonstrable we observe the Sun in the present in its present relative position to the observer.
 

Offline alancalverd

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #2 on: 23/12/2015 20:51:03 »
Not possible. What you see is light that emanated from the sun about 8 minutes ago, so by the time you see it, the earth  will have revolved about 2 degrees from where it was when the light left the sun. So when the sun appears to be overhead London, it is actually overhead Gloucester.
 

Offline Space Flow

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #3 on: 23/12/2015 21:35:31 »
Demonstrable we observe the Sun in the present in its present relative position to the observer.
Really?
It is actually demonstrable that due to the finite speed of light you can't even see your own hand in the present, let alone the Sun. What sort of pseudoscientific comment is that?
 

Offline Phractality

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #4 on: 24/12/2015 02:08:29 »
This subject is covered in
Travelling at the Speed of Thought: Einstein and the Quest for Gravitational Waves, Kennefick 2006, with reference to a 1909 paper by Einstein and Ritz. The illustrations are on pp 162, 163.

Last I checked, that link was a free PDF download of the 500-page book.

It looks to me like they are saying the spherical shells of light remain centered on the source in all inertial reference frames, even if the relative motion follows a straight line, rather an a circular orbit.

I am trying to relearn what little I used to know of Blender software. That's a bit like learning Italian so you can order pizza. I don't happen to have a pea shooter, so a stealth bomber will have to do.

I have drawn some circles to illustrate what would happen if you passed a pulsating star in a straight line at v =c/2. Now I have to relearn how to render the picture.
 

Offline GoC

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #5 on: 24/12/2015 02:35:19 »
That is simultaneity of Relativity.
 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #6 on: 24/12/2015 02:54:41 »
Not possible. What you see is light that emanated from the sun about 8 minutes ago, so by the time you see it, the earth  will have revolved about 2 degrees from where it was when the light left the sun. So when the sun appears to be overhead London, it is actually overhead Gloucester.

Not possible, or a sniper would always miss the target.





« Last Edit: 24/12/2015 03:01:20 by Thebox »
 

Offline alancalverd

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #7 on: 24/12/2015 12:04:41 »
They usually do, until they learn to lead on a moving target. Ask any game or clay pigeon shooter! It's a particularly difficult skill for air gunners: if your bullets are travelling at 1000 mph and your target is crossing at 600 mph, you need to be very good at mental arithmetic, which is why antiaircraft shells and guided missiles use proximity fuses, and successful ship-to-air gunnery often consists of just letting everything rip at once. 
 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #8 on: 24/12/2015 15:09:52 »
They usually do, until they learn to lead on a moving target. Ask any game or clay pigeon shooter! It's a particularly difficult skill for air gunners: if your bullets are travelling at 1000 mph and your target is crossing at 600 mph, you need to be very good at mental arithmetic, which is why antiaircraft shells and guided missiles use proximity fuses, and successful ship-to-air gunnery often consists of just letting everything rip at once.

I have done some air rifling in my time, to shoot a moving target we account for velocity, gravity and wind, we do not account for light, we set a trajectory that will intercept the target.  We shoot and aim ahead of the target, in the targets future.

We would miss the target if it was not in the present,


Lets a rabbit is travelling from point A to point C, but according to you the target starts at A but is actually at B, so when we aim at B, the target is already at B, so when we fire we miss because when the target is at B, it is actually at C, relatively making no logical truth-ness.
 

Offline GoC

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #9 on: 24/12/2015 15:56:11 »
The  Box

 alancalverd is correct. You do not understand simultaneity of relativity. Reflected light leaves the object. Now the object moves forward while the photon moves towards your eye. The photon is always moving toward you but the object is also moving relative to the finite speed of light. We always view objects in their past position. Depending on the distance and speed of the object it is no longer where you view the image. Consider stars in the sky. None are where you view them to be while some are not even in existence any longer. When we watch a super nova it happened years before we see the image of the event. Einstein suggested only 10% of the population could understand relativity. I remember reading this somewhere. To understand light has a finite speed similar to a bullet through space this is also finite speed is simultaneity of relativity. When a bullet hits its target you view its past when the light hits your eye. In our environment the speed of light is indistinguishable from infinite speed of light which is your current basis of understanding.
 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #10 on: 24/12/2015 16:53:28 »
The  Box

 alancalverd is correct. You do not understand simultaneity of relativity.

But I do understand simultaneity of relativity and it is wrong,


I have shown it before but here it is again




You look at a planet in the present not in the past.

 

Offline Phractality

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #11 on: 24/12/2015 17:30:42 »
I'm sure you've all had this experience: You hear a high-flying jet overhead; you look up in the direction from which the sound is coming. You don't see the jet there; instead, you see it maybe 30 to 45 ahead of where the sound is coming from.

If the jet is flying in a circle with you at its center, you still hear it coming from its "retarded position", 30 to 45 behind where you see it. I'm not sure if that's exactly the case. Can that be proven? Try simplifying the problem by assuming the speed of sound is the same everywhere, regardless of altitude, and there is no wind.

Let's say that jet passes 10 km directly above us; the sound takes 30 seconds to reach us. To simplify the problem, let's say the speed of light is infinite, so we see the jet exactly where it is now, as opposed to where it was when the sound we hear was emitted. (This is analogous to the assumption that the speed of gravity is infinite, compared to the speed of light.)

A though experiment:

[In round numbers] Your ultra-quiet maglev train is eastbound in a straight line at 33 m/s; sound travels 1 km in 3 sec. Kids at ground zero, one km north of the track, are setting off M80 fireworks at one second intervals. Do you hear the bangs coming from the direction where you now see ground zero, from the direction where ground zero is, or some other direction?

Now, let's switch tracks; the new track is circular, centered on ground zero, with a radius of 1 km. I think the sound would seem to come from approximately (or exactly) the direction where we see ground zero. What say you? Anyone bold enough to present a proof?


What makes sunlight behave different rules? Or does it?

A bit of philosophizing:

The question of where the Sun IS NOW is an existential question. Can we really know where something has gone to since it emitted the signal that we are now perceiving? "IS NOW" is merely a snapshot of a model that we have conceived to make sense of what we perceive.
 

Offline GoC

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #12 on: 24/12/2015 21:49:51 »
Relative time is the same. You view revolutions in relative time of course but the image takes light years to get here. A recording through time.
 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #13 on: 24/12/2015 22:11:07 »
Relative time is the same. You view revolutions in relative time of course but the image takes light years to get here. A recording through time.

I don't agree . The physics would be all wrong when considering trajectories etc. 

Consider the light from an object takes the same time to reach an observer as the observers light to reach the object being observed, there is no time discrepancy. The position is fixed to each other .
 

Offline GoC

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #14 on: 24/12/2015 22:40:27 »
Each view the other in the others past trajectory position. You can never view the position of an object in the present. This is because light is finite and not infinite. This understanding is necessary to understand relativity.
 

Offline Phractality

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #15 on: 25/12/2015 02:55:23 »
Consider the light from an object takes the same time to reach an observer as the observers light to reach the object being observed, there is no time discrepancy. The position is fixed to each other .

That is true for inertial reference frames. If one observer accelerates, time will pass more slowly for him.
 

Offline Colin2B

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #16 on: 26/12/2015 10:51:48 »
Relative time is the same. You view revolutions in relative time of course but the image takes light years to get here. A recording through time.

I don't agree . The physics would be all wrong when considering trajectories etc. 

Consider the light from an object takes the same time to reach an observer as the observers light to reach the object being observed, there is no time discrepancy. The position is fixed to each other .
The very fact that light takes time to travel means we don't see objects in their local time. In the other direction they don't see us in our local time either. This is just the same as the time taken for sound to travel, we don't hear in local time either.
What you are forgetting for air rifles is that the speed of light is so fast and the distance so short that we can ignore the delay. Over space distances we can't.
 

Online jeffreyH

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #17 on: 26/12/2015 16:37:24 »
We can use a coordinate system with an x and y axis marked off in units. Then have two objects in our coordinate system at separate locations. If object A is at the origin and object B is at coordinates x=4, y=4 we can then set some rules of motion. We can say that object A and object B are constrained to move along parallel to the x-axis. Object A moves in a positive direction and object B moves in a negative direction. Further, we can also say that both objects move 1 unit in the same interval of time so that their speeds are equal and opposite. If both objects release a 'particle' at the start of their respective trajectories to be detected at some future point by the other object then we can model what happens with light. We can state that these particles move two units in 1 unit of time and so are twice the speed of objects A and B. When object A has moved i units in the positive direction it will detect the particle from object B. When object B has moved j units in the negative direction it will detect the particle from object A. The positions that the objects will determine for each other will not reflect where the objects were originally. In fact i and j may not even be integer multiples of the unit of measurement. Most likely they won't. This is in a coordinate system that is rigged to be simplistic. It takes no account of special or general relativity. It is easy to make statements about what may be personally intuitive. To provide some sort of proof mathematically comes with all sorts of challenges that you don't even know are there until you learn some physics.
 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #18 on: 26/12/2015 18:55:14 »

The very fact that light takes time to travel means we don't see objects in their local time
. In the other direction they don't see us in our local time either. This is just the same as the time taken for sound to travel, we don't hear in local time either.
What you are forgetting for air rifles is that the speed of light is so fast and the distance so short that we can ignore the delay. Over space distances we can't.


The very fact my diagram says your very fact is wrong and time is parallel




if m1 (the top circle)  travels 8 mins to the right, so does m2 (the bottom circle)



« Last Edit: 26/12/2015 19:14:23 by Thebox »
 

Offline GoC

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #19 on: 27/12/2015 17:08:56 »
We only live in the present. All of us no matter your clock speed. The present is where we live and when you view an image it was from the past. No one lives in the future since life is always in the present. Time is motion and motion is always the present.
 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #20 on: 27/12/2015 23:02:44 »
The present is where we live and when you view an image it was from the past.


The present is where we live and we view all things in the present through the clear of light. You are not accounting for clear.
 

Offline GoC

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #21 on: 28/12/2015 00:32:27 »
You do not see through anything. An image reaches your brain when it hits your eye. When you look at a tree the image comes to you, you do not see through space. A close image comes to you before a image at a further distance. The longer distance is further in the past. You do not see clear, your image is unobstructed.
 

Online jeffreyH

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #22 on: 28/12/2015 00:49:06 »
Another point which is pertinent is the nature of observation when looking out into space. We are never viewing the exterior (to our planet) laws of physics as they pertain to our present but to a past that may be 1 year or 1 billion years ago. This may tell us something about how forces operated at that point in the history of the universe but may not be pertinent to its present state. We should expect to find anomalies at different epochs that indicate some sort of evolution in the expected states of the various force fields.
 

Offline Thebox

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #23 on: 28/12/2015 14:25:03 »
You do not see through anything. An image reaches your brain when it hits your eye. When you look at a tree the image comes to you, you do not see through space. A close image comes to you before a image at a further distance. The longer distance is further in the past. You do not see clear, your image is unobstructed.



You don't see light either, you see matter interacting with light, you see this interaction through the coupling of the clear(white light) , a variable wave, the only light that reflects into your eyes is when a glare catches your eyes, otherwise you are submerged in the clear light, a constant coupling of the brain to space.
 

Offline GoC

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #24 on: 28/12/2015 15:33:54 »
Photoreceptors in the eye detect waves of a certain frequency range. How waves are transferred through space through is unknown but mass is required to create the waves. If mass is energy than photon virtual particles with a tail. If energy (dark mass energy) is the source of the transfer than it is a wave range of particles where the particles stay but continue the ripple through space. Both would be energy transfer.

Either way light cannot be created without mass. Even virtual photons would lose mass from the proton which we do not measure so which is more likely?
 

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Re: Do we see the Sun where it was 8.3 minutes ago?
« Reply #24 on: 28/12/2015 15:33:54 »

 

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