# Do We See Light In The Space Between Objects?

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### #1 xyz

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Posted 14 June 2016 - 02:26 PM

There is a clear line of sight between myself and an object, the air is transparent and is also present between my eye and object, do we see light in that space or do we only see light that enters our eyes?

Also, I can see distance ,  between my eye and object I have a clear line of sight, I see the entirety of the spacial distance between eye and object, so why is it said that it takes 8 minutes of time for the light from the sun to arrive and why is it said we observe the Sun in its past if we can quite clearly observe the start point and end point of the clear line of sight of the distance between?

### #2 pzkpfw

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Posted 14 June 2016 - 06:34 PM

I've seen your posts elsewhere (e.g. http://www.thenakeds...p?topic=67136.0 ) so will get straight to an analogy:

Alice lives in London, and Bob lives in New York.

On Wednesday, Bob's time, Alice sends an airmail letter to Bob. On Friday (the letter took two days to travel), he opens and reads the letter.

In a way, Bob is getting information from Alice - that came from "the past".

Is that really any issue?

Maybe Alice sends a letter every day, so Bob receives a continual stream of letters.

On his Saturday he gets her letter from his Thursday. On his Sunday he gets her letter from his Friday. And so on. On every day, his time, he's getting information from "the past".

Is that any issue?

It's the same thing with light. Light takes time to travel, so by the time light hits our eye we are seeing something as it was in our past. e.g. we see the Sun as it was 8 minutes ago (our time).

As long as there's a continuing stream of light from an object to us, we keep seeing it, but we're always going to be seeing its "past".

(Of course, in relativity, the idea of "now" gets a little complicated, but that's not needed to answer your OP).

Edited by pzkpfw, 14 June 2016 - 06:37 PM.

### #3 pzkpfw

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Posted 14 June 2016 - 06:48 PM

Further:

When Bob reads Alice's letter, he has no idea about what happened to the letter in between her and him.

But - what if one of the postal workers handling the letter had dirty hands? Bob might see fingerprints on the envelope ... and could even identify the postie.

In terms of the title of this thread, "Do We See Light In The Space Between Objects?", the answer is no.

We only "see" by light entering our eyes. So if you are seeing a distant object, you are not seeing the space between you and that object; unless something is affecting the light.

Look out of your window and see a tree; light from that tree is hitting your eye, that's how you see the tree.

If a truck parks in front of that tree, maybe you can't see the tree any more, because light from something else is now getting into your eye.

Or maybe the truck isn't directly blocking your view of the tree, but the fumes from its exhaust are in the air between you and the tree; that might affect the light reaching you from the tree, perhaps making it fuzzy or hazy.

In both cases, you don't see the space between you and the tree, but something in that space could affect your view of that tree.

### #4 pzkpfw

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Posted 14 June 2016 - 06:55 PM

Finally:

I think you are partly letting yourself be confused by the high speed of light and the apparent low speed of the Sun. So try this ...

Imagine you are sitting in a chair with your eyes closed. You are facing a footpath (sidewalk) about 100 m (33 hogsheads) in front of you. Approaching from your right, and moving towards your left, is someone running on that footpath.

You can hear their steps.

At the moment you hear each step, will they still be in the same position they were in when they made that specific footfall, or will they have moved on a bit?

If they suddenly stopped running, would there be immediate silence, or would the sound of their last footfall still be on it way to you?

### #5 xyz

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Posted 15 June 2016 - 12:20 AM

In terms of the title of this thread, "Do We See Light In The Space Between Objects?", the answer is no.

Thank you for the reply, the forum you mentioned has banned me for wanting to discuss this topic, they said I insulted members which I did not.

Straight to the point , I do not see how the answer is no when obviously the space is not dark and obviously we can see the entirety of the clear line of sight between any objects.

If we consider y-axis is the light that enters your eye, then why can I also see a distance apart of anything on the horizon x-axis if I am not seeing light in that space between the horizon objects?

I can ''see'' there is air a foot away from me? (notice ''see'' does not actually mean see as the air is transparent and ''invisible'')

Edited by xyz, 15 June 2016 - 12:23 AM.

### #6 pzkpfw

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Posted 15 June 2016 - 12:46 AM

Thank you for the reply, the forum you mentioned has banned me for wanting to discuss this topic, they said I insulted members which I did not.

I saw those posts. I didn't realise they'd banned you, but you did deserve it. Anyway, this is a different forum, and another chance for you.

Straight to the point , I do not see how the answer is no when obviously the space is not dark and obviously we can see the entirety of the clear line of sight between any objects.

In a "clear line of sight" you are not seeing anything at all between you and the distant object. You don't see the distance, you see the object.

Have you ever seen a movie where a valuable item is secured by lasers to detect thieves? You can't see the lasers from the side. The hero has to spray something into the air, or blow dust into it, so that some of the laser light is reflected to his or her eyes (and ours, via the movie screen).

When you see something, you are reacting to light that left the object, from wherever it is, and which has traveled the distance between you and that object, until it hits the retina in the back of your eye. You are not "seeing the distance" between you and that object.

You seem to be imagining some "magic" in the ray of light.

If we consider y-axis is the light that enters your eye, then why can I also see a distance apart of anything on the horizon x-axis if I am not seeing light in that space between the horizon objects?

I really can't parse that.

I can ''see'' there is air a foot away from me? (notice ''see'' does not actually mean see as the air is transparent and ''invisible'')

No, you can't see that air. You know it's there, but what you're seeing is an object some distance away from you, light is travelling (at finite speed) from that object, through the air, to your eye.

Edit:

Imagine the Sun has a switch, and it's off. Everything is dark.
Now the switch is turned on. Everything is still dark.
After 4 minutes, light from our Sun is rushing towards Earth (and the rest of the Universe); the space halfway from Earth to the Sun is full of photons.
But for you, everything is still dark.
You can't see the light that's halfway from the Sun to you.
After 8 minutes, that light starts to reach you, it enters your eyes, and now your brain can tell you "the Sun is back on".
(And you'd know that it was turned on, 8 minutes ago).

Edited by pzkpfw, 15 June 2016 - 01:08 AM.

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### #7 xyz

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Posted 15 June 2016 - 07:08 AM

I saw those posts. I didn't realise they'd banned you, but you did deserve it. Anyway, this is a different forum, and another chance for you.

In a "clear line of sight" you are not seeing anything at all between you and the distant object. You don't see the distance, you see the object.

Have you ever seen a movie where a valuable item is secured by lasers to detect thieves? You can't see the lasers from the side. The hero has to spray something into the air, or blow dust into it, so that some of the laser light is reflected to his or her eyes (and ours, via the movie screen).

When you see something, you are reacting to light that left the object, from wherever it is, and which has traveled the distance between you and that object, until it hits the retina in the back of your eye. You are not "seeing the distance" between you and that object.

You seem to be imagining some "magic" in the ray of light.

I really can't parse that.

No, you can't see that air. You know it's there, but what you're seeing is an object some distance away from you, light is travelling (at finite speed) from that object, through the air, to your eye.

Edit:

Imagine the Sun has a switch, and it's off. Everything is dark.
Now the switch is turned on. Everything is still dark.
After 4 minutes, light from our Sun is rushing towards Earth (and the rest of the Universe); the space halfway from Earth to the Sun is full of photons.
But for you, everything is still dark.
You can't see the light that's halfway from the Sun to you.
After 8 minutes, that light starts to reach you, it enters your eyes, and now your brain can tell you "the Sun is back on".
(And you'd know that it was turned on, 8 minutes ago).

Thank you for your explanation and explaining present information.  I do not mean to sound rude or ungrateful for your help , but what you are telling me I already understand and this is why forums become confused in my opinion, I tell the members I know this already and I am questioning the integrity of the information.  The members then reply and keep replying with present information rather than actually having their own view points and discussing the ''why'' that I ask.

I already understand in great detail ''your'' present version, repeating it back to me does not answer my queries on the information or will further my knowledge on the subject, people presume for some strange reason that I do not understand or know the present information.

Science in short explains sight to be the act of the eyes receiving ''information packets'', a Photon containing the information of the object.

I obviously with the knowledge of modern day science, know that light can contain information  and be sent from a transmitter to a receiver where the information is decoded into e.g  Pictures or sound on a television.

So I can see why science thinks the way ''it'' thinks, I am not the stupid individual people think I am.

However, my personal observation of my surroundings differs from the present information and this is why I am questioning the present information, the student is questioning the teacher about the validity of information compared to everyday observation.

The student feels that if he was to accept any information, the information must have axiom's  justifiably and no unjustified assumptions.

Why do we call it a clear line of sight then say this clear line of sight has Photons travelling to our eyes when we do not see photons in the clear line of sight?

I see an object in it's exact geometrical position, I am sure you do too?

We can prove distance exists and  the object is in it's exact Geometrical position by walking over to it?

I see ''empty'' space as a transparent whole?

''Empty space'' couples my sight to objects, I can see the end point and start point of a ''Photon's'' journey because I have a clear line of sight?

added- On other forum, the moderator claimed we see wavelengths of 400nm-700nm in ''empty'' space, contradictory to your answer.   I said we only only see visible light 400nm-700nm of spectral content, i'e colours and that space was colourless and visually ''gin-clear''?

Edited by xyz, 15 June 2016 - 07:25 AM.

### #8 billvon

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Posted 15 June 2016 - 12:48 PM

There is a clear line of sight between myself and an object, the air is transparent and is also present between my eye and object, do we see light in that space or do we only see light that enters our eyes?

You only see the light that enters your eye.  You do not see any light that does not enter your eye, by definition.

Also, I can see distance ,  between my eye and object I have a clear line of sight, I see the entirety of the spacial distance between eye and object, so why is it said that it takes 8 minutes of time for the light from the sun to arrive and why is it said we observe the Sun in its past if we can quite clearly observe the start point and end point of the clear line of sight of the distance between?

Because it does in fact take 8 minutes for the light to reach us.

### #9 xyz

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Posted 15 June 2016 - 01:29 PM

You only see the light that enters your eye.  You do not see any light that does not enter your eye, by definition.

Because it does in fact take 8 minutes for the light to reach us.

You are just repeating what Pv said, however your post give me a question, if you claim you can only see light that enters your eyes, then how can you conclude it takes 8 minutes to arrive when you are saying that you can't see outside of your head?

### #10 pzkpfw

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Posted 15 June 2016 - 01:33 PM

You are just repeating what Pv said, however your post give me a question, if you claim you can only see light that enters your eyes, then how can you conclude it takes 8 minutes to arrive when you are saying that you can't see outside of your head?

Actual experiments have shown us what the speed of light is (and it's not infinite). We know the distance to the Sun.

So it's absolutely obvious that light we receive from the Sun has taken time to travel to us.

Tell me, if a sniper shoots you from 200 m away, when will you feel the bullet?

A: When the sniper squeezes the trigger?

B: When the bullet is half way to you?

C: When the bullet hits you?

Edited by pzkpfw, 15 June 2016 - 01:34 PM.

### #11 pzkpfw

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Posted 15 June 2016 - 01:39 PM

...

Why do we call it a clear line of sight then say this clear line of sight has Photons travelling to our eyes when we do not see photons in the clear line of sight?

We call it clear line of sight because nothing is obstructing the photons on their way from the distant object to us.

That seems pretty simple.

I see an object in it's exact geometrical position, I am sure you do too?

No. We see it in the position it was in when the light left it.

Did you read my sitting in a chair with eyes closed analogy?

We can prove distance exists and  the object is in it's exact Geometrical position by walking over to it?

By the time we walk to it, it may have moved, but, more or less, yeah.

I see ''empty'' space as a transparent whole?

''Empty space'' couples my sight to objects, I can see the end point and start point of a ''Photon's'' journey because I have a clear line of sight?

Not quite. For a distant star you look at at night, when you see the star you are receiving light that left it many years ago. The concept of "now" gets difficult over long distances, but more or less; that star will no longer be in the place it was when that light left it.

### #12 xyz

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Posted 15 June 2016 - 01:41 PM

Actual experiments have shown us what the speed of light is (and it's not infinite). We know the distance to the Sun.

So it's absolutely obvious that light we receive from the Sun has taken time to travel to us.

Tell me, if a sniper shoots you from 200 m away, when will you feel the bullet?

A: When the sniper squeezes the trigger?

B: When the bullet is half way to you?

C: When the bullet hits you?

Obvious the answer is c but a ''photon'' is not a bullet, I find no evidence on the internet of a photons existence, I do not observe photons in the clear line of sight between eye and object, I have to question the said existence of a photon when my own observation is not providing me with an observation of a photon.

Do you see photons in ''empty'' space ?

### #13 xyz

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Posted 15 June 2016 - 01:42 PM

We call it clear line of sight because nothing is obstructing the photons on their way from the distant object to us.

That seems pretty simple.

What photons ? it is a clear line of sight, ''gin'clear''

Not quite. For a distant star you look at at night, when you see the star you are receiving light that left it many years ago. The concept of "now" gets difficult over long distances, but more or less; that star will no longer be in the place it was when that light left it.

And the receiver is in a different place and could not possibly receive a photon travelling a linear vector, it would miss the target because a sniper has to account for motion.  In 8 minutes I assure you the Earth as moved and no longer a linear target for a single ''photon'' that leaves the sun.

While the ''photon'' travels 8 minutes a linear path, the earth follows its orbit and the photon misses the earth.

Edited by xyz, 15 June 2016 - 01:59 PM.

### #14 pzkpfw

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Posted 15 June 2016 - 01:48 PM

What photons ? it is a clear line of sight, ''gin'clear''

Light is photons.

You see a box over there. You have clear line of sight.

All that means is that photons can leave that box and travel over the distance between you, to your eyes.

The air between is "gin clear", it's allowing those photons to travel.

### #15 pzkpfw

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Posted 15 June 2016 - 01:51 PM

Obvious the answer is c but a ''photon'' is not a bullet, I find no evidence on the internet of a photons existence, I do not observe photons in the clear line of sight between eye and object, I have to question the said existence of a photon when my own observation is not providing me with an observation of a photon.

Do you see photons in ''empty'' space ?

Actual experiments have shown the existence of photons. Your incredulity doesn't alter that.

You don't see photons in empty space, because sight is about photons hitting your retina. (Same as bullet-caused pain is about the bullet hitting you).

See my laser-security example.

### #16 pzkpfw

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Posted 15 June 2016 - 02:02 PM

And the receiver is in a different place and could not possibly receive a photon travelling a linear vector, it would miss the target because a sniper has to account for motion.  In 8 minutes I assure you the Earth as moved and no longer a linear target for a single ''photon'' that leaves the sun.
While the ''photon'' travels 8 minutes a linear path, the earth follows its orbit and the photon misses the earth.

Of course the Earth has moved. But the Sun is sending light out in all directions. Light you receive now is light that went in the correct direction to get to you "now"; it's not light that went in the direction that would have hit you 8 minutes ago.

For this, don't think sniper, think duck shooter. They have to aim in front of the flying duck.

### #17 xyz

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Posted 15 June 2016 - 02:09 PM

You don't see photons in empty space,

An honest answer, we do not directly observe/see photons in space, ok good we are in agreement of something.

For the moment can we forget about Photons being detected by the eyes and discuss the above?

Would you agree that when you don't see photons in ''empty'' space, you see ''empty space'' as an ''empty'' whole?

Please regard the question and answer on what you see around you..