A revolution in thought

[Dragar]

[Dragar]

So this post is for peacegirl.

peacegirl, Lessans wrote that a distant astronomer would see Columbus landing on the new world the instant it happens.

If he was right, we should be able to see a moon of Jupiter come out of eclipse the moment it happens, too. That is exactly what Huygens wanted to test in the 17th C.

He knew when Io would come out of eclipse (his friends had calculated it for him). But Jupiter had moved a long way from Earth after the initial observation of the eclipse starting. If we could see it happen instantly (like Lessans says) it wouldn't matter how far away Jupiter was. We would see it when the moon came out of eclipse. On the other hand, if we did not see it happen instantly (the opposite of what Lessans says), it would take longer than anticipated to see the moon reappear - because our calculations would be off, by the fact the light took some extra time to reach us.

Huygens was right; it took longer than expected. This is the opposite of what Lessans predicts. He showed we do not see things happening at great distances happen instantly. We see them when the light arrives.

[Dragar]

[davidm]

Of course, the moons of Jupiter example was discussed with her in minute detail about 350 pages ago. We all see what good that did.

[Dragar]

Originally Posted by LadyShea

Well, Lessans instantaneous seeing means that light travel time and distance are not factors in sight.

Isn't time relativity related to light travel time and distance?

She also doesn't believe time exists, FWIW, she is a Presentist

Absolutely it is related. But logically, you can have light travelling at a finite speed and not have relativity (that is what the early Michelson-Morley experiments were about testing). Anyway, Lessans certainly contradicts relativity. But most of Lessans claims seemt to very simply contradict the finite speed of light. I think that is a much simpler place to explain the problems.

[davidm]

Originally Posted by Dragar

Absolutely it is related. But logically, you can have light travelling at a finite speed and not have relativity (that is what the early Michelson-Morley experiments were about testing). Anyway, Lessans certainly contradicts relativity. But most of Lessans claims seemt to very simply contradict the finite speed of light. I think that is a much simpler place to explain the problems.

This is a point worth noting. Even if relativity theory were an incorrect theory, and we lived in a different kind of world, if the speed of light were finite, then Lessan's claims are automatically invalid. It could be the case, for example, that light behaved the way in which the Michelson-Morley experiments assumed it would: traveling at different rates of speed under different conditions. That turned out not to be the case. It was Einstein's insight that the speed of light was constant relative to all observers that introduced relativity theory.

But even in a non-relativistic world, unless the speed of light were infinite, then Lessan's claims are impossible. We know the speed of light is finite. Hence, Lessans' claims are all false.

[ceptimus]

This post about the moons of Jupiter was made on 2nd April, and is on page 39 (if you use the standard number of posts per page).

[LadyShea]

Originally Posted by peacegirl

This is not hard to set up. I don't need some special lens. All I would have to do is have someone go far enough that he would be out of direct view of a standard digital or film camera. It would have to be a clear day with no obstructions that could cause the light to be dispersed, absorbed, or deflected. If we are getting the image from the photons bouncing off of this person, it should show up on the lens. If it shows nothing, what does that tell us? I would then tell the person to come into view of the camera's field of view. If one of the pictures shows nothing, and one shows the image of the person, there is a discrepancy that should not be present.

peacegirl. Here's some stuff from Wiki regarding photography that you would need to understand in order to set up your experiment in a valid way. I don't understand all of this, myself, but it all applies to your posited experiment involving a person standing beyond the vanishing point and trying to take a picture of him/her.

The optics of photography involves both lenses and the medium in which the electromagnetic radiation is recorded, whether it be a plate, film, or charge-coupled device. Photographers must consider the reciprocity of the camera and the shot which is summarized by the relation

Exposure ∝ ApertureArea × ExposureTime × SceneLuminance[75]

In other words, the smaller the aperture (giving greater depth of focus), the less light coming in, so the length of time has to be increased (leading to possible blurriness if motion occurs). An example of the use of the law of reciprocity is the Sunny 16 rule which gives a rough estimate for the settings needed to estimate the proper exposure in daylight.[76]

A camera's aperture is measured by a unitless number called the f-number or f-stop, f/#, often notated as N, and given by

f/# = N = frac fD

where f is the focal length, and D is the diameter of the entrance pupil. By convention, "f/#" is treated as a single symbol, and specific values of f/# are written by replacing the number sign with the value. The two ways to increase the f-stop are to either decrease the diameter of the entrance pupil or change to a longer focal length (in the case of a zoom lens, this can be done by simply adjusting the lens). Higher f-numbers also have a larger depth of field due to the lens approaching the limit of a pinhole camera which is able to focus all images perfectly, regardless of distance, but requires very long exposure times.[77]

The field of view that the lens will provide changes with the focal length of the lens. There are three basic classifications based on the relationship to the diagonal size of the film or sensor size of the camera to the focal length of the lens:[78]

* Normal lens: angle of view of about 50° (called normal because this angle considered roughly equivalent to human vision[78]) and a focal length approximately equal to the diagonal of the film or sensor.[79]
* Wide-angle lens: angle of view wider than 60° and focal length shorter than a normal lens.[80]
* Long focus lens: angle of view narrow than a normal lens. This is any lens with a focal length longer than the diagonal measure of the film or sensor.[81] The most common type of long focus lens is the telephoto lens, a design that uses a special telephoto group to be physically shorter than its focal length.[82]

Modern zoom lenses may have some or all of these attributes.

The absolute value for the exposure time required depends on how sensitive to light the medium being used is (measured by the film speed, or, for digital media, by the quantum efficiency).[83] Early photography used media that had very low light sensitivity, and so exposure times had to be long even for very bright shots. As technology has improved, so has the sensitivity through film cameras and digital cameras.[84]

Other results from physical and geometrical optics apply to camera optics. For example, the maximum resolution capability of a particular camera set-up is determined by the diffraction limit associated with the pupil size and given, roughly, by the Rayleigh criterion.[85]http://en.wikipedia.org/wiki/Optics

[Dragar]

Originally Posted by ceptimus

This post about the moons of Jupiter was made on 2nd April, and is on page 39 (if you use the standard number of posts per page).

I think it is possibly important to seperate out 'seeing' from 'light' when talking to peacegirl. This moons of Jupiter example is perfect because it involves an event happening that can be seen. With no CCDs or radio waves in the way, we don't really need to talk about light, except as a coherent explanation for both vision and for why the delay happens. The experiment itself is just about when we see things, and is good enough to serve as a counterexample to Lessans.

Anyway, we can try again along this route, being a bit simpler, and see what happens.

[davidm]

Originally Posted by ceptimus

This post about the moons of Jupiter was made on 2nd April, and is on page 39 (if you use the standard number of posts per page).

Oh, memories!

Reading on a little to the next page, I stumbled on this great quote from Teh Book of Teh Seymour:

"I am going to put a mathematical end to all premarital sexual intercourse.

Seriously, his book is one of the most amusing things ever written, though not written with the intent to amuse, of course.

That should be some equation, Seymour!

[But]

Originally Posted by LadyShea

We can read license plates from photos taken by orbiting satellites for goodness sake,

No we can't.

IMINT - Resolution - Reading License Plates and Headlines

[LadyShea]

Thanks But, looks like I repeated an urban myth. See peacegirl, I am not God's gift to science at all, I make mistakes.

I wonder if the technology exists to be able to read a license plate from orbit, even though it may not be in current use? That page But linked to is from 1997, surely we have more powerful resolution today?

Originally Posted by Yahoo answer guy so maybe BS

The largest lens in space that I know of is 2.4 m in diameter (Hubble Space Telescope) -- it is actually a combination of mirrors, but the calculation is the same. The theoretical discrimination is 0.05" (=0.0000135 degree = 0.000000235 radian).

At an orbit height of 589 km, the theoretical resolution of an object on Earth's surface exactly under Hubble would be 589,000,000 mm * 0.000000235 = 138 mm (5 inches). Difficult to distinguish letters that are less than that size.

[ceptimus]

The space telescope, Herschel, has a 3.5 metre mirror, compared to Hubble's 2.4

However, as Herschel works in the infrared, the resolution is poorer than could be obtained from an optical light telescope of the same size.

The James Webb Space Telescope, if it is ever launched, will have a much larger mirror - equivalent to one of 6.5 metres.

[peacegirl]

Originally Posted by LadyShea

I have hit a sore spot, huh?

You haven't hit a sore spot; you are the sore spot. Just kidding. I actually like your participation, but you get me frustrated sometimes.

Originally Posted by LadyShea

I understand what Lessans was trying to say about light and sight, and I understand the consequences of it. You are the one that doesn't understand how his claims don't fit with reality.

And I am far from God's gift to science, I just have a good enough grasp of the basics to see the problems with your ideas.

I explained you need to understand the factors involved in an experiment in order to create an experiment, and you freak out.

Who seems to be wrong in that case?

Because you are bringing in extraneous factors that have nothing to do with the experiment except to make it look flawed.

[peacegirl]

Originally Posted by Dragar

peacegirl, does this book of yours actually make this claim? That if God turned the Sun 'on', people would notice it immediately?

How is this different from the experiments I talked about with torches? We know in that case that it would take time to see the torch turned on. So we know that if God turned the Sun on, it would take eight minutes. What makes turning the Sun on different to turning on a torch?

It's really not different. Can you link me to this experiment? I would like to see it for myself just to make sure we're talking about the same thing.

[peacegirl]

Originally Posted by LadyShea

Why yes Dragar, I have a suggestion. She said this hypothetical was "correct"

This indicates he didn't understand that time was relative, and that instantaneous seeing could cover even 800 light years

Okay, this was hypothetical in the sense that we can't see 800 light years away. But if it was possible (due to a powerful enough telescope), we would see the present, not the past.

[peacegirl]

Originally Posted by davidm

Yes, we can move on the excerpts where Lessans claimed that light was made of "molecules," which peacegirl later altered to "photons," while insisting that it was impossible for her to alter one jot or tittle of the sacred text.

We can talk about the excerpt in which Lessans claimed that when Columbus landed in the New World, if an astronomer on distant Rigel were looking at the earth through a powerful enough telescope, he would see Columbus landing in real time, BUT if a TV picture of Columbus landing were broadcast, it would take 900 some years to reach the astronomer on Rigel! That excerpt was good for a belly laugh, let me tell you.

That is not what he said and you know it.

Decline and Fall of All Evil: Chapter Four: Words, Not Reality p. 121

Since it takes
longer for the sound from an airplane to reach our ears when it is a
thousand feet away than when five thousand, it was assumed that the
same thing occurred with the object sending a picture of itself on the
waves of light. If it was possible to transmit a television picture from
the earth to a planet as far away as the star Rigel, it is true that the
people living there would be seeing the ships of Columbus coming into
America for the first time because the picture would be in the process
of being transmitted through space at a certain rate of speed. But
objects do not send out pictures that travel through space and impinge
on the optic nerve. We see objects directly by looking at them and it
takes the same length of time to see an airplane, the moon, the sun,
or distant stars.

To sum this up — just as we have often observed
that a marching band is out of step to the beat when seen from a
distance because the sound reaches our ears after a step has been
taken, so likewise, if we could see someone talking on the moon via a
telescope and hear his voice on radio we would see his lips move
instantly but not hear the corresponding sound for approximately 3
seconds later due to the fact that the sound of his voice is traveling
186,000 miles a second, but our gaze is not, nor is it an electric
image of his lips impinging on our optic nerve after traversing this
distance.

Originally Posted by davidm

Or we can talk about how Seymour claims that when the photons from the sun arrive on earth, they are waiting there to "smile on you" while you sleep on the unlighted side of the earth. It appears he thought that the molecules of light were like gas molecules, just sort of floating about waiting for you to wake up so they can say "Good morning!" Of course all those other trillions of photons generated every second by the sun are coming down and colliding with the ones that stopped at the earth, creating a huge pileup of photons, and by the time you wake the temperature on earth would be about the same as that of the sun, and so you'd die instantly.

That's not what he was implying.

Decline and Fall of All Evil: Chapter Four: Words, Not Reality p. 121

Once the light is here it remains here because the photons
of light emitted by the constant energy of the sun surround us. When
the earth rotates on its axis so the section on which we live is in
darkness, this only means the photons of light are on the other side.
When our rotation allows the sun to smile on us again this does not
mean that it takes another eight minutes for this light to reach us
because these photons are already present.

[Dragar]

Originally Posted by peacegirl

It's really not different. Can you link me to this experiment? I would like to see it for myself just to make sure we're talking about the same thing.

Unfortunately, most modern experiments doing this use extremely complicated technology. I don't want to get into a discussion about this technology. Instead, let's use the example of seeing the moon Io appear from behind Jupiter. This was done such a long time ago that the basic principles (even the technology) is readily instead, and we don't need to get embroiled in the details of what is going on. Instead we can focus on what we see.

You can read about it here. The only difference is that instead of turning on a torch, the moon Io comes back into view from behind Jupiter. We see it after the fact. If we didn't, our calculations should not need to include a 'travel time' for the light.

Could you explain why this appears to completely contradict what Lessans says? It seems from carefully examining the world, that we don't see in 'real time' at all.

[Spacemonkey]

Originally Posted by peacegirl

The light that is being emitted or reflected is being projected onto the lens of the retina or a camera to produce the image. It's not that mysterious Spacemonkey.

You know full well that does not answer the questions I've been asking. Stop avoiding the issue.

[Dragar]

Originally Posted by peacegirl

Okay, this was hypothetical in the sense that we can't see 800 light years away. But if it was possible (due to a powerful enough telescope), we would see the present, not the past.

To be clear, we all understand that this was a hypothetical. But we have tested this possibility over many hundreds of years now. And it has turned out to be wrong.

[Spacemonkey]

Originally Posted by peacegirl

How can you say photons are not their own light source? They are producing light.

No, Peacegirl, they are not. How can you have spent so may years on this and still not even understand what light is?

[peacegirl]

Originally Posted by Dragar

Well, I would like peacegirl to explain why that description of the world is different to all our experiments.

You can test that principle yourself with no fancy electronics. You can do the experiment with your eyes. Huygens did it just like that (albeit with a telescope and the moons of Jupiter, but that's nothing more than a pair of glasses and a very distant sun suddenly being turned on).

Dragar, I believe experiments closer to home will yield the same results, if they are correct. That's why I wanted to do a less costly experiment. It would involve a large expanse of open space and a professional camera.

1. A person would be just out of sight of a camera's field of view but in a straight line on a clear day to see if his image would show up on the lens of the camera.

2. The camera's lens would be checked for size.

3. There would be no obstructions between the person and the camera for the light to be deflected, absorbed, or dispersed.

Results: Will the person's image show up on the lens of the camera due to light only?

Second experiment:

1. A person would come forward where he was in the field of view of the camera.

2. There would be no obstructions for the light to be dispersed, absorbed, or deflected.

3. Are the results similar or different? What does this tell us?

Please tell me if this experiment would be reliable, and if not what can we do to tighten the variables.

[peacegirl]

Originally Posted by Spacemonkey

No, Peacegirl, they are not. How can you have spent so may years on this and still not even understand what light is?

Light, which is emitted and absorbed in tiny "packets" called photons...

Light - Wikipedia, the free encyclopedia

[Dragar]

Originally Posted by peacegirl

Dragar, I believe experiments closer to home will yield the same results, if they are correct.

I am afraid I don't understand your experiment, as you described it, at all. However, we have done 'closer to home' experiments similar to Huygens one (actually, far more similar to 'torches on a hill'). If you read that link I gave earlier, you can read about Fizeau and Foucault who carried out such an experiment. The great difficulty of doing it 'closer to home' is that the speed of light is so very fast, any time delay is very small on terrestrial scales. This ends up meaning you need to use quite clever tricks or complicated devices - and I don't want to end up discussing how these things work.

They all give the same result, incidentally, and show light travels at a finite speed, and that we don't see things in 'real time'.

[davidm]

Originally Posted by peacegirl

Light, which is emitted and absorbed in tiny "packets" called photons...

Light - Wikipedia, the free encyclopedia

So you think giving a link to a wiki article about light is any evidence that YOU understand what light is, and that YOU know how it functions?

What don't you tell us IN YOUR OWN WORDS what it is, and how it works?

Of course, if you were actually able to do that, then you would see at once what all the rest of us spotted inside of five seconds: Lessans' claims about light and sight were not just WRONG, but the arguments that he formulated, such as turning on the sun at noon and seeing it immediately from earth, but not seeing one's neighbor for eight and a half minutes, were logically self-contradictory.

Now, peacegirl, what about the moons of Jupiter? Are you going to attend to Dragar's points, or not?