thank you :)

↪ — Rich

I couldn't find this code. So I have to use quote or @. Where is this broken arrow?

[quote

I'm always looking for new ideas. Some of the best ideas I've heard have come from folks who have to observe nature closely in order to survive, e.g. those who love in the city streets. I am only interested in ideas. I can work out the details myself. — Rich

thank you

Where is my image now? (2)
Instead of beams, imagine that the ray box was housing five colored windows whose reflections did not reach beyond a few centimeters. How would the image of the ray box have looked like?

I will tell you. We would have had an inverted image of the ray box with its five bright windows. The question is, would the images of these windows meet at a single point, like the beams do? Or would the whole front surface of the ray box be projected on a screen?

My point is that the beams attract all the attention and make us forget that it is the whole scene we should be considering.

It is a little bit like the use of a magnifier to start a fire by reflecting the sun onto a single point. The accepted wisdom is that the point is in fact an image of the sun. I find this very improbable. It is as little an image of the sun as the bright spot formed by the ray box is an image of the 5 beams.
If you want an image of the sun you would have to go beyond the focal point.

There is a hidden hint here somewhere.If we want an image of the lights in the ray box, we need to go beyond the focal point, somewhere where the image of the whole ray box is projected. And if we want an image of the ray box, we would need to temper somehow the beams, just like we use a gray filter to be able to look at the sun.

The hidden hint seems to me to be the following: the beams of light do not constitute the image of the objects, but only an image of themselves. We have to go beyond the beams to be able to see the objects or their images.

@T Clark
I am too old to interview for a job I do not want. My qualifications are my posts and comments. If you need references before you can respond to an opinion then you should only read articles of established journals.

Where is my image now?
Imagine you are using a ray box like this gentleman , with 5 beams you pass through a converging lens. Where do you think an image will be formed of those 5 beams?
At the focal point of course?

You sure about that? It seems to me that we have to go beyond the focal point to see anything resembling individual beams.
Imagine you put a screen exactly at the focal point, I think what you will get is, literally, a burning point, the literal translation of focal point in Dutch and German.

If you wanted an image of all 5 beams, and of their spatial relationships, you would have to go beyond the focal point. And the farther you go, the larger the image will be.

Should the image be at its sharpest at the focal point? Very doubtful, when all beams are inextricably mixed with each other. In fact, if you look carefully at the clip you will see that there is a moment where all 5 beams are clearly distinguishable. I would say, that is the smallest and sharpest image of all five beams, even if it lies quite a (relative) distance from the focal point.This distance will of course depend on the resolution of your optical devices.

That is also the position given usually by ray tracing. So, what is the use of the focal point?

I would say that the view of five beams coming out of a ray box should convince anybody of the falsity of ray tracing.
Ray tracing would take each beam and consider it as propagating rays in all directions through the lens, and it would be these rays, coming from a single point that would cross each other not at the focal point, but somewhere before or after, and create a virtual or real image.

In a way, ray tracing is right. There can be no image of an object at the focal point, only the smelting of all rays in one bright spot. It is only after rays start distancing themselves from each other that an image is formed.

But if we look at the video clip we clearly see that each beam goes its own way, even if they all meet at the focal point. There is no propagation of light in all directions from each point of the source.

@Rich
I do not share your enthusiasm for Bergson, even if I do feel much sympathy for his ideas. Einstein has opened the way of thinking about space in a non-Newtonian way (mathematicians were before even Einstein in their quest for non Euclidean geometries), and maybe we should keep looking in this direction, and not consider the results of the 20th century as immutable.
I confess that I find the fact that we can see across immense distances with a telescope as something that has not been fully analyzed in all its consequences.

@ T Clark
why are you so hostile? If you think I am not credible, just ignore me.

edit: let us not hijack this thread.

I am suspicious of theories rejected by the consensus of the scientific community. If you look, there are lots of people that say relativity and quantum mechanics are hoaxes. At the same time, I am sympathetic to the frustration that comes from not understanding the chain of inference that scientists follow on complex issues. It would be helpful if we could get someone on the line who knows the science well — T Clark

Your suspicion is shared by many. I find it reassuring that not any objection to the consensus is blindly accepted. I understand the need for Science to be conservative, and set the bar higher. At the same time, discussions of what seems to be an eternal truth should not be silenced. Your suggestion that only people who do not understand a theory do not agree with it is very condescending, and, I am convinced, wrong.
Science changes, and what was regarded as beyond doubt becomes obsolete. Let us not forget that. As Einstein once said to his audience during one of his lectures, yesterday you all believed in the ether.

Can you elaborate on that response. You seem to be implying that I have based my assertions on what you said. — MikeL

Why would I think that? I prefer to think that great minds meet, don't you?

Sorry to steal your thunder. I would love to hear your thoughts — MikeL

Let me first state that I have of course no way of knowing whether the universe is really expanding or not. As it has been noted, the sole argument in favor of expansion is the color shift (red), and that is itself based on a theory that is accepted by everybody... except by me. But since I am, in academic terms, a nobody, don't let it deprive you of your sleep.

see also

https://philpapers.org/post/17834

I was considering creating such a thread myself. It is not necessary anymore.
https://thephilosophyforum.com/discussion/comment/104721

I will take it as meaning that you have no further arguments to present except the expectation that everybody should accept the rules of Optics as they are presented in textbooks. I will indeed continue pursuing my own agenda. You came out very strong, but in the end all you can refer to is the authority of science. You could of course very well be on the right track, and I could be all wrong, but your attitude is not really convincing and does you no honor.

Now, just move your head around while looking through the hole. If the hole is small enough, you only see a small point of color. Suppose your head is in such a position that you see a point of red on the door of a parked car. Move your head much lower and you might see a point of blue from the sky, — oysteroid

I would like to present you with another problem related to the Aperture Problem.

You give in your description of image formation in a camera obscura, the example of a person looking through the pinhole and seeing different parts of the scene according to his positioning. I have no problem whatsoever with such a description because it starts with the receiver, the eye, and not the sender, the light source.
I will just mention in passing that the size of the hole certainly determines how much the eye can see.

Imagine now that our spy not only is hidden in a dark corner, but that he is also in a dark closet with a very small peephole, a camera obscura as it were.

We may assume that no light, as far as we can perceive, reaches the closet nor the peephole, leaving the spy confident in his hiding place, even though he can still see the people he is spying on some distance away in a bright place.

Obviously, when putting his eye to the hole, he will see the scene straight up because it is projected upside down on his retina, as it would on the back wall.

That is in fact my question. assuming the scene is reflected, upside down, but that is unimportant for now, on the back wall of the closet, how would you explain it? Did the light rays stop illuminating the part of the space closest to the closet just to start again when they hit the wall?

Please let me know what you think of this.

edit: obviously if the peephole is too small there will be no visible reflection on the wall, but since we are not interested in sharp images, all we need is a bright spot as an acceptable image of the scene.

The larger the aperture, the less the light on any given point on the screen is restricted to just one part of the scene. So, being less restricted, there is more light, but less sharpness. — oysteroid

The second half of the quote is even more interesting, and concerns what I have called the Aperture problem, and which you have so conveniently ignored.

Your idea is ambient light coming from all directions, and rays reflected by the objects, also coming from all directions, contribute to the sharpness of the picture. I find it a very strange argument seen as the aperture, as we both agree, does not have any influence on the field of view, however strange it might seem.

Let us suppose that we are filming in a closed space, a box, with measuring marks on the bottom through the whole length or width. Let us now take different pictures with the camera as close to the box as possible to make sure only light within the box is reflected back. We will use different apertures, and appropriate lighting, to see if the depth of field changes.

According to your explanations, there should not be any difference between the different shots, at least, not in sharpness and depth of field, if of course we have adjusted the shutter speed accordingly.
After all, with each aperture we are receiving light back from the same enclosure. In fact, with adjusted shutter speeds, we are receiving the same amount of light back.

Add to that the fact that light rays are supposed to cross each other at the focal point, and we have no reasons left to think that the image should in any way be altered by different apertures.

I would be very interested in your opinion as to why, under such circumstances, we would still witness a change in sharpness and depth of field with different apertures.

Candle Light

Here is an experiment I wish I could do myself, but I am afraid my apartment is not big enough.

Choose a large closed space with no windows, and light a candle at the end of the room. Hold or hang a mirror at the other end, and see if the image reflects the light of the candle.
The distance between the candle and the mirror must be of course large enough, and the room must be dark enough, that without the candle the mirror remains invisible.

There are as far as I can see only two possibilities, both very interesting.

1) No image on the mirror. This would be very improbable, after all, if we can see the candle, why would the mirror not reflect it?

2) The candle is reflected on the mirror. But then, how is the image projected through space onto the mirror through the dark? But then, how are stars in the sky visible to the naked eye?

edit: the mirror has of course to remain invisible even after the candle has been lit, at least, from where the candle is standing, even if that would not work for the reflection of the light.

The larger the aperture, the less the light on any given point on the screen is restricted to just one part of the scene. So, being less restricted, there is more light, but less sharpness. — oysteroid

I agree with this description of the way the amount of light affects visibility. It seems reasonable also to me to assume that a larger aperture will mean a brighter image. Where I depart from your conceptions is by the role this ambient light plays in the forming of images.

Let me take the same example as previously of a spy in the dark watching people unseen. If he decides to take pictures of the (illuminated) scene, he will have to take into account not his location, in darkness, but the light falling on the people, incident light. He won't be able to get any closer to take a reading of reflected light, so incident light, with the proper light-meter, will have to do.

Here is the crux: even though he is in complete darkness he will have to take into account the light illuminating the scene, and adjust the shutter and aperture accordingly. His camera is also in complete darkness, but still, closing the aperture will result in darker images that would have to be compensated with longer shutter speeds, and vice versa.

The question now is, why does he need to do that if no light is reaching him or his camera? Or is this assumption wrong? Can we say that the images registered by his eyes and through his camera have been somehow projected by light rays on his retina and the sensor area? If that is the case, how could he remain invisible to the other people?

Why would telescopes have no use if they don't allow us to see things as they presently are? It is much better to see Pluto as it was hours ago than to not see it at all! Surely it is good to be able hear someone from across the room even though it takes time for the waves in the air to reach my ear! — oysteroid

Tell it to the military of all nuclear (super) powers that are counting on detecting a hostile missile enough time in advance to react before they are destroyed.

Concerning the fact that it takes time for sound to reach your ears, I can't recall ever claiming that it was not true.

This is easy to explain. Once again, just consider the geometry. This says all that needs to be said on the matte — oysteroid

To be honest, I find your objections quite inadequate. You make it look like I am at loss concerning the geometric issue and you simply ignore the reason why I pose the problem. It is easy to refer to scientific authority as being the final judge in History, but please remember that Aristotle was the sole source of wisdom for 2000 years, and that the concept of the ether has been considered for longer valid than has the concept of field. The fact that the majority or even all the scientists today agree on something is not a guarantee of its validity.

As far as mysteries are concerned, I agree with you about the importance of say, consciousness, but that does not mean that we should consider the Book of Nature as already read.

edit: I could not find Einstein's quote about the error of thinking that we already know what light is.

I am afraid I don't follow your thinking on instant light propagation at all and I don't see how it relates to cat eyes and pre-exposure of film. There is a mountain of evidence for the fact that it takes time for light to travel and that when we see distant objects, we are seeing how they were in the past. We can actually see this — oysteroid

That is I think the central point of this discussion. Though, if you have read my posts carefully you will know that I do not believe in instant propagation of light. My post on femtophotography makes it clear that I consider propagation of light as something that happens in time.

I have the impression that instead of answering to my objections you find it sufficient to refer to established and accepted theories. The point you bring up, "when we see distant objects, we are seeing how they were in the past." is what I am denying. I wish you could explain to me how we can see somebody, or something, from a very large distance, and that person or object only arrives hours after we have made the observation. If we were observing the past how could there ever be such a discrepancy between past and present. It takes only a few moment for light to reach our eyes, while the object of our observation has to cross the distance at whatever speed is available.

What happens with a projector is as follows. Light comes from a lamp and is sent through a condenser lens and then passes through the film. Let's stop here for a moment. What is happening at the film is once again nothing but restriction of the light. The film is basically casting a shadow. The light coming through the slide does not "get colored". The light before the slide is already composed of photons of many different wavelengths — oysteroid

Again, I cannot fault your knowledge of Optics. I think ray tracing, unlike wave theory, is very intuitive, and both do a great job at explaining what we see. It is very difficult to falsify these theories based on immediate perception. We can see light rays being bent by lenses, crossing each other at the focal point and then creating a (real) image on a screen. Thats is certainly the strength of Optics in all its versions, geometric, physical and quantic.

My issue with Optics is that it does not explain vision, and that therefore what we see is more complicated than the optical theories want us to believe. I will not repeat my arguments about distant objects and their relation to the speed of light but let me mention a very simple argument concerning vision.

We can see illuminated objects even if, at least apparently, no light is reflected into our eyes. We can stand in complete darkness and spy on people.

Huygens' Principle speaks about wavelets that would somehow keep the main wave going. In other words, he was trying to take into account a very fundamental and elementary empirical fact: light beams when they have a certain direction do not disperse sideways indiscriminately. The more they disperse, with distance, the more light looses intensity. Therefore, light does not go on indefinitely but ceases altogether after a while. And we are now expected to believe that light coming from trillions of kilometers away can still somehow reach our eyes? For that we have to accept what every scientist considers as an anathema: perpetuum mobile. An electric field creates a magnetic field that creates an electric field... ad infinitum.

If light could go on indefinitely why does it stop when going through matter? Friction? Sure, that is as good an explanation as any. But tell me, suppose you shine a powerful light on earth, would it be visible from the moon? Why, after all, it would have stopped after a few kilometers?. Did it somehow regenerate during its travel to the moon?

Back to Huygens. If you suppose that somehow a light beam directed away from us, or an illuminated scene we watch from a dark and hidden corner, reach our eyes anyway, then you must accept the principle that they will remain visible from any distance. Just like the beam is supposed to go on indefinitely.
But then, that would contradict Huygens' Principle in which the wavelets contribute to the sustenance of the main beam. If they have to use energy to propagate in all directions, whatever the direction of the main beam, then how could light go on indefinitely? Where would the energy come from?

These are some of the reasons why I think Optics, and with it the theory of the dual nature of light, are lacking in explanation power.

A last, but certainly not least argument, is the fact that we can cross immense distances without having to move from our place. Telescopes, and microscopes, seem not only to manipulate light, they manipulate space. Maybe all we are seeing is an epiphenomenon, hoe light reacts in a spatial field distorted by lenses.

I will be first to admit that this a very far-fetched solution and I do not know how seriously we should take it. Still, that is certainly something to consider if we accept the fact that telescopes show us objects where they are, at the moment they are there.

Interference and Anti-Sound

Destructive interference has until now apparently already found a practical application in the audio-field. One can even find clips on Youtube made by wizkids that demonstrate this peculiar phenomenon.

The problem is that we are in fact dealing with a self-fulfilling prophecy. Here is what Wikipedia has to say on the subject:

"Modern active noise control is generally achieved through the use of analog circuits or digital signal processing. Adaptive algorithms are designed to analyze the waveform of the background aural or nonaural noise, then based on the specific algorithm generate a signal that will either phase shift or invert the polarity of the original signal. This inverted signal (in antiphase) is then amplified and a transducer creates a sound wave directly proportional to the amplitude of the original waveform, creating destructive interference. This effectively reduces the volume of the perceivable noise."

In other words, the so-called anti-noise is in fact a software routine.

Theoretically it should be possible to create the antithesis to any sound. The movement of the inner membrane in the ear can be expressed mathematically, and the inverse formula can be calculated. But before that we would have to decipher, in real time, the serial sequence produced by the so-called "hammer" or malleus hitting the anvil or incus. It is this serial sequence, which, again theoretically, can easily be translated into a binary progression, that moves the membrane in a certain way.

As you see, anti-sound is certainly not impossible, only very improbable in the near future. And as for destructive interference? It is still merely a theoretical suggestion.

By the way, optical destructive interference has been known already since the 19th century, with the advent of photography: each time you hold a negative in your hand, you are looking at the product of what could be called destructive interference: white becomes black and vice versa.

Move your head much lower and you might see a point of blue from the sky, since you'll be looking up through the hole. The important thing here is to see that any given point in space is only receiving light from one point in the scene, found by tracing a line from that point in the room to that point in the scene. — oysteroid

I honestly do not know what makes us see objects. In my example of a distant star for instance, I do believe that we see it there where it is, at the moment it is there, just like we see a person coming in the distance, and it takes him time to reach us. It takes him time, because the light he reflects is so fast that we don't even have time to blink (even if it is finite).

Am I advocating action at a distance? At this point all I can say is that I am not excluding anything, and I do not consider the concept of field anymore immune to criticism than the ether was.

I am inclined to agree with your description of each point on the screen receiving light from the scene. Only, I would put the emphasis on the receiving side. I also have to confess that my hypothesis still needs a lot of work and I understand the appeal of ray tracing.

What extra light that gets through the lens doesn't come from objects depicted in the image? With a less than ideal lens, like a real lens, you get lens flare and whatnot. But the phenomenon in a cat's eye you are talking about is just light, focused as usual by lens and iris, that happens to miss the rods and cones striking material slightly beyond the rods and cones and reflecting back toward the rods and cones, where it has a second chance of being detected. — oysteroid

You have given a crash course in optics and I think that many people will find it very useful; I thank you in their name. I will not try to reply to all the points you have made, it would take many days, if not weeks, and more patience than anyone might have on this forum. Let me first state that you obviously know the subject as it is taught in colleges and universities. My aim is to show that the established theories leave many questions unanswered, among those, the point you bring up in the quote above.

Light that "happens to miss the rods and cones" is reused, enhancing the sensibility of the eye cells. You will agree with me that where they get reused is, from our point of view, quite random. The point is, light that is not directly reflected by an object can be used to brighten the image of this object.

There is an old technique in analogue photography called pre-flashing. It consists in exposing very briefly the film to unfocused white light, and this has as a consequence that the emulsion as it were awakens and stands to attention. The real story concerns the number of ions and electrons that are activated by this pre-flash, and which get added to those activated by the subsequent shot, but details are unimportant.

What is important is the fact that light that does not come from or is not reflected off an object contributes to its brightness and visibility. That is also the main point I am trying to make when I argue that when we are looking at an object through a telescope, we are seeing the object there where it is, at the moment it is there. That is impossible according to Optics which says that the light reflected or emanating from the object must reach our eyes first. I beg to differ. Telescopes would be of no use whatsoever.

Interference is a central concept of the wave theory of light. The idea is deceptively simple. Waves that end up at the same location while having different phases will destroy each other. Simply put, a crest and a crest reinforce each other, while a crest and a trough cancel each other out. This is also believed to be the case when light has to go through one or more slits creating fringes of light and dark spots. The dark spots are supposed to be the result of destructive interference.

I find the concept of interference, in spite of the many examples and arguments, quite unconvincing. For one, it is based on an arbitrary definition of color whereby white and black are defined respectively as "all colors" and "no color" and even "no light".

Here is what I think is an argument against the validity of Interference.
When one shines primary colors on a screen, the point where all three colors meet is white. Using complementary colors instead, we get a black spot. This is seen, and I find this very strange indeed, as negative interference, and the black is an indication of this. The center of the complementary beams is something that does not exist!

Usually a white screen is used, so you would expect simply to see the still existing screen. But somehow even the white screen disappears behind the non-existent phenomenon.
Which makes you wonder: if primary colors still show the white screen, shouldn't we consider the result of their mix as transparent? It would make a lot of sense since ambient light allows us to see through and walk around, which would be very difficult if it were white.

Transparent light as the result of primary colors, and an opaque black when complementary colors are involved. Makes sense to me.

Another thing. Interference is supposed to be dependent on the difference in arrival time. If two waves differ by an odd multiple of the wave length then they will interfere destructively with each other. That is something that is easily investigated. All we have to do is shine three complementary beams on a screen and vary their respective distances enough to cover all possibilities. I wonder, do you think there will be settings where three complementary colors would not give black? I must admit that I have not tried it myself, but I would certainly be interested in the outcome.

"You have to use monochromatic light!" I hear you objecting. Okay, let us do it with two beams of the same wave length and shine them on a screen, varying the distance between the sources incrementally. However difficult it might be, there must be a way of showing interference patterns?
"You have to use one or more splits!" Ah, that is more problematic. See, I want to understand interference, not the effect of splits on light beams. I already know that there will be fringes with bright and dark spots. What I am interested in, is what those fringes means. And for that, I need to understand what destructive interference is.

Femto-photography

You have probably heard of the experiment in which the speed of light, or at least its motion, was captured on film. One could see how a ray of light propagated from one location to the other, confirming if ever the need was, that light is not instantaneous but has to travel through space and matter to reach its goal.
Imagine you are standing in the path of the beam, looking at it approaching. Then you will see the head of the ray first, slowly (!) followed by its tail. But there is something funny going on here. When we watch the clips in which the ray of light is slowly coming to life, we see it appear too soon. That is of course because the pictures have been taken one at a time long before, and we are watching it from aside. We are not watching a live event, even if that it is the impression that is conveyed.

Still, let us imagine, for the sake of argument, that we are filming with a highly advanced camera the way light propagates from a distant object towards the lens. Just like a human observer, we should see first element1 appear, then element2, and so on. The ray would appear to our eyes, and to the camera, as moving away from us, starting from our own location. At the risk of becoming a second Poisson, the blundering scientist, not the gifted mathematician, I will say that this would be quite strange, though of course not impossible. After all, we are all familiar with wheels turning backward in movies.

Still, maybe a remake of Fizeau's experiment would be possible in the near future. It could look like this:

1) a telelens directed at the light source to register the exact moment light appears after the switch has been locally turned on.
2) Fast digital cameras to capture the (time) path of the light beam.

This would help us, hopefully once and for all, determine whether light appears at any location only after the time necessary to reach that location. Or if it can be seen as soon as it appears, there where it appears, from any location in space.

To see the beam of light as approaching us we would need to perceive it as growing slowly towards us. That is we would have to see each photon as it is created, without having to wait for it to reach our eyes.

http://web.media.mit.edu/~raskar/trillionfps/

Distance and Size

One of the most obvious but still unexplained phenomenon is that objects appear smaller with distance. It is obvious, and we could not imagine it being otherwise, even if we dot really understand how that works. Let me reiterate: our spatial logic is based on this fact and it will probably seem strange to even make it a point of discussion.

Here is the problem I see. Objects do not simply appear to become smaller, apparently they become smaller in reality, even if this shrinking down is only relative to an observer! Who needs Quantum mysteries when we experience them everyday!

Imagine holding an infinitely extendable rope attached to the outside edges of a vehicle. The farther the vehicle will move away from you, the smaller the distance between the both ends of the rope you are holding will be. In other words it seems like the vehicle is shrinking in width.
That is obviously not the case. Still, now the same vehicle, which was much wider than you when it was close to you, has become small enough to take but a fraction of the space on your retina. The distance between both edges of the car, in fact all its dimensions, has shrunk just like the distance between the ends of the rope your are still holding. The object has shrunk not only optically, by geometrically. The example with the ropes and the vehicle can easily be put in the drawing of an isosceles triangle and lines parallel to the base all the way to the top, these rungs symbolizing the width of the vehicle. Geometry tells us that objects shrink with the distance for a particular observer. Why didn't Einstein think of that?

Interesting, but you are considering the phenomenon distance as experienced by the subject as potential or actual action. I was more thinking in terms of what distance means first independently of the perceiving subject. The moon gets reflected on the surface of the lake whether there is a witness or not.

If we accept the idea that we see objects there where they are, at the moment they are there, we have to accept the fact that the reflection of the moon on the lake obeys the same principles. Non-locality, or rather, trans-locality should be considered as an objective phenomenon. A phenomenon, allow me to empathize it once again, that is incompatible with the idea of images being transported by light through space in time.

Yes, Quantum Theory and The Mysteries of Creation. If I were the pope I would declare Bohr and his companions all saints.

I would be really interested in what you think of my claim in the other thread: https://thephilosophyforum.com/discussion/2024/romer-and-the-speed-of-light-1676#Item_14

We see objects where they are at the moment they are there. That is the only thing that explains how a telescope functions.

I see an obvious link between both threads as you may easily imagine.

Concerning Fermat's Principle: https://philpapers.org/post/26486

@Rich
Thank you for the link.
Bergson dared put into question the idea that mathematics is the "language of nature" as Galileo announced so proudly. Since then we can say that Galileo has been the unchallenged champion and Bergson, in spite of his Nobel Prize, has been relegated to the "oubliettes". Like Bergson, I do not think that the language of Nature is Mathematics for the simple reason that mathematics is a human language and bears all our strengths and weaknesses. It is an indispensable tool for Science, with the emphasis on "tool".

Have you ever looked at the reflection of a tree or a pole on the water? When you walk around it, you can only see it from one angle. Also, you do not see it anymore where you saw it before. If light were reflected in all directions, you would expect to see the tree or pole reflected all around.

Another thing: the idea that light is reflected in all directions may be mathematically plausible, it is physically much less. Each point in space will probably only be able to reflect light in one direction, or at least in a limited number of directions. Also, I think that the images we receive of objects are just too neat for the idea of an infinite number of directions from each point in space. Sharp images would be a miracle, don't you think?

I am glad you mention mirrors and even pinholes. They make the matter in fact not simpler but vastly more complicated.

Mirrors reflect scenes straight up, while lenses reflect them up upside down.

Pinholes create upside down images without a lens! The image on the back of a pinhole camera is perceived upside down. The retinal image we would receive if we were to stand in the camera obscura would be straight up, meaning that we would also see an upside down image.

The question now is, how come light rays travel in straight horizontal lines when dealing with mirrors, but suddenly start crossing each other when going though a pinhole or a lens?

I think, without any proof, that instead of thinking of rays that somehow know whether they will be dealing with mirrors or pinholes/lenses, we must think in terms of the receiving surface.

When the opening of a room keeps shrinking to the point where only a small pinhole is left, the only way to look outside and see anything is to lower your body to look up, and stand on your toes to look down.

Translated to what the molecules of the wall or screen can do, they can only capture light coming from the opposite corner. If it is down left, light has to come from up right to be captured or seen, and so on.

In other words, we must at some point stop thinking in the way light behaves, and concentrate on how reflecting surfaces, including lenses, behave.

Is the universe expanding?
Not if Rømer was wrong and we are seeing distant stars the way the admiral was seeing the enemy ship: there where we see them, and not as something shown by light rays traveling trillions of kilometers and taking millions of years to reach us . The question therefore whether Rømer was right in his assumptions has far-reaching consequences that go well beyond some ratiocinations about perception. That is why the discussion of his claims should not be considered as closed once for all. This is an attempt to reopen a discussion that scientists believe has been solved a very long time ago. I claim that they are wrong.

@Rich

https://philpapers.org/bbs/thread.pl?tId=897#p8097
https://philpapers.org/bbs/thread.pl?tId=1002#p9701
https://philpapers.org/bbs/thread.pl?tId=1006#p9742
https://philpapers.org/bbs/thread.pl?tId=1011#p9778
https://philpapers.org/bbs/thread.pl?tId=1015#p9837
https://philpapers.org/bbs/thread.pl?tId=1021#p9877
https://philpapers.org/bbs/thread.pl?tId=1026#p9932

Concerning Bergson, I think I have read almost all of his books, in French, in high-school. He and Camus were my favorites. But then, I was very young.

Perception theory, as well as the established theory of light (duality of light) are both based on an assumption that has always been considered inattackable . Even the Ancient Greeks who believed that the light came from our own eyes, just like a flash light in the dark, were, I think, of the same opinion.
This is hardly surprising, after all nothing is visible in the dark: no light, no perception.
This still does not explain the complicated fact of perception. Light as a conditio sine qua non of vision does not mean that light needs to be reflected off objects into our eyes for us to see these objects.
Here is a simple example: a light beam directed away from me will still be visible, as will be the light at the end of a tunnel even if I am standing in complete darkness. It would be difficult to argue that light rays somehow are reaching my eyes when there is no indication of it whatsoever. Furthermore, light intensity diminishes with the square of the distance. After a while, light stops and darkness takes over. That does not mean that somebody who stands way beyond the illuminated area cannot see the light in the distance.
If we link these thoughts to the original discussion then we can wonder whether we are seeing the stars because their light takes time to reach our eyes, or if we see them just like we see a light on earth that does not shine beyond a very limited distance.

Of course perception is involved in every aspect of human life and knowledge. As far as suggesting, it seems to me that it is what you are doing. I would welcome arguments against my analysis.

I honestly have no idea what you mean.

@Rich
I saw my second post more as a clarification of the problem posed in the first one. Are we allowed to speak of the speed of light as we do if we are able to perceive distant objects in real time? If looking through a powerful telescope had allowed Rømer to see in real time the reappearance of Jupiter's moon, would he have had any reason to believe that it takes time for the images to reach us? That would in fact mean that the admiral would hardly have any advantage on his officer ( a few milliseconds). Only if the admiral saw the enemy ship there where it was at that time does a telescope have any use for the military. Otherwise it would be just another scientific toy with no strategic significance.

Replace the enemy ship with Jupiter's moon and you would have to admit that Rømer 's calculations are meaningless.

Imagine you point a super Hubble-telescope towards Jupiter to see when IO reappears from behind its planet. Next to you is a colleague with a much less powerful telescope. Would both of you see IO appear at the same moment?

Let's get down to earth in the time of Galileo who is still trying to sell his (stolen) invention to pay his many debts. An admiral of the Venicean navy is using the new revolutionary device, while a lower officer is staring at the horizon hoping to detect an enemy ship before, or at least not too long after his superior. The question is, what would determine the difference between the time the admiral detects the ship, and the time in which the lower officer does the same in turn? It is in fact a very simple operation: if the difference is equal to the time it takes the ship to get in visual range of the naked eye, then we can say that the telescope is showing the location of the ship in real time. If, on the other hand, the difference between the detection times is negligible, then we can say that the telescope allows us to see objects not there where they are, but where they were when their light started its travel towards us.

Now, let me ask you this. What would be the strategic advantage of seeing an enemy ship a few (milli) seconds earlier? Especially in the 17th century. Also, if it is correct, what does it mean that a telescope allows us to see distant objects in real time?

I've often resented the fact that philosophy is barred or seen as detrimental to talk about QM. — Posty McPostface

I see QM as a metaphysical theory in scientific clothes and philosophers should be much more engaged in its discussion. But as always scientists hide behind their formulas and equations which, as far as I can see, are correct, once you have accepted the premises.
https://philpapers.org/post/18786
https://philpapers.org/post/19070