Sun and Moon

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Wolfshadw

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Just asking for clarification. Is this the viewpoint you're trying to get across? Granted this is 2D.




If not, could you clarify?

-Wolf sends
 
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We would expect that the parallel rays from the Sun would always give us the illuminated horns to be perpendicular to the Sun, but that's clearly not what we see, except at quarter phase.
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Exactly and that is what I'm questioning. What I/we see is that the 'horns' are not perpendicular to the sun so why is this? It gets more interesting because as time progresses the sun rises in the sky but the moon's illumination remains the same.
 
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Can you tell by just the photo? No. Not unless you can also determine the angle between the football and the ground. You need something else to use as a reference.
Obviously, I know that! But, from just a photo you can reasonably work out roughly from which direction the light comes from, front right, front left, up or down relative the to, say, bottom of the photo. Or if you prefer the side of the photo. Just choose your own datum position and work it out from that.
 

Wolfshadw

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See if this helps. The Top-Down view shows why it's a Gibbous moon.
The Earth/Sun Plane view shows your orientation and the moon below the Earth/Sun plane. which is why the lit side of the moon appears to be pointing up from the Sun.



Does that help?

-Wolf sends
 
Jan 19, 2021
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See if this helps. The Top-Down view shows why it's a Gibbous moon.
The Earth/Sun Plane view shows your orientation and the moon below the Earth/Sun plane. which is why the lit side of the moon appears to be pointing up from the Sun.



Does that help?

-Wolf sends
Thanks for the diagram but it doesn't really help. Perhaps my drawing will.https://www.dropbox.com/s/r9igkqvhdbwrevi/Drawing 7.jpg?dl=0
It doesn't make any difference where in space you view the moon-sun system the light from the sun should always be perpendicular to the moon's illumination but my observation shows that it isn't. I do realize this is a hard thing to say but I cannot argue with physics.
 
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That's a great example!

Did you look at the paper from post #27?
No I missed that one but have since looked at it.
I have heard this argument before and it doesn't hold water. The first statement suggests its an 'illusion'. I believe this is because it is not what is expected even though physics and logic say otherwise. Rather than change the idea, the facts are changed to fit the idea. This is done by invoking the 'celestial sphere' which is just as much a 'convenience' construct, like the roof of the Planetarium and my 'straight line' between a torch and a football. The celestial sphere does not exist any more than it would in a square box that measured 6' x 6' x 6' or one hundred million light years cubed.
There is a fundamental problem here that nobody wants to honestly address. I can talk like this because I am not encumbered by traditional astronomy ideology i.e. basically and with respect I am saying that 'The Emperor appears to have no clothes on'.
 
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I have heard this argument before and it doesn't hold water. The first statement suggests its an 'illusion'.
It's more than reasonable to call it an illusion since it's silly to suggest sunlight is bending or doing something bizarre to account for what is seen.

I admit to not reading but a tiny bit of the paper, and some things I disagreed with, but I hoped you might be able to make better sense of it as it was quite formal.

There is bound to be something out there that can present an accurate explanation, hopefully with convincing illustrations or a video. But my limited search efforts, admittedly, have failed.

One physicist I found in an article uses the angle of the shadows of two people standing away from a point source of light. When close, the angle is great, when far away from the light, their angles become more and more parallel. This analogy doesn't work for me, unfortunately. I'm still convinced (subjectively), nevertheless, that distance is the key,

There is a fundamental problem here that nobody wants to honestly address.
Who do you see as being dishonest? [Or did you mean "seriously address"?] Most enjoy giving their honest thoughts, but sometimes they don't want to commit to hours of research to address what should be a simple answer. That's what I see.

I can talk like this because I am not encumbered by traditional astronomy ideology i.e. basically and with respect I am saying that 'The Emperor appears to have no clothes on'.
You're missing the key tenet of science - discovery. The more scientists can discover new things, or falsify other's theories, the more science, and they advance.

Are you suggesting there could be an answer to what we see that is ATM - Against The Mainstream?
 
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Are you suggesting there could be an answer to what we see that is ATM - Against The Mainstream?
Thank you for your thoughtful comment and yes I only say that because of what I and others actually observe. Nobody would dispute the football - torch system but do when the system is increased in size by many orders of magnitude. Why is this?
To me calling it an 'illusion' is not much different than calling it a 'conspiracy theory'. This epithet tends to be used when people's deep-seated belief system is being challenged by facts. By facts I mean hard evidence and not just another belief system. This is called 'cognitive dissonance' and I have experienced this a few times during my liife but fortunately was able to accept the challenge and adjusted my thinking accordingly.
 
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The first illustration is not only correct but demonstrably so. We enjoyed our stay in TN during the last great eclipse. We were in the umbra and those outside the umbra saw a partial eclipse (ie penumbra area).

We see the same thing during a lunar eclipse where the Moon can be clearly seen to enter the umbra caused by the Earth's shadow. But it can also be seen to diminish when in the penumbra area.

The lower illustration is inaccurate because it represents non-extended objects (ie point sources). Starlight produces the parallel rays as shown, no doubt.

Extended objects (2D light sources) necessarily have different angles we draw to the limbs. This is shown appropriately, if not to scale of course, in the first drawing. [I also take issue with the Sun's color but that's another story. :)]

I do hope someone can resolve your OP (Opening Post) question as it is a great one. Perhaps I will have time to give it some thought if others don't respond soon enough.
 
Jan 19, 2021
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I too am hoping that someone can answer my original question re the lunar illumination.

All the diagrams that I see illustrating how the sun illuminates the earth and moon all show the light rays as being parallel. we can't have it both ways! Another interesting point with these diagrams is that although they show the various phases they never show the angle of the phase.

1 How can a sun that is shown to be the same size as the moon, during an eclipse, produce a penumbra?
2 Why are the light rays shown to 'cross' halfway between the sun and moon and also between the sun and earth when the moon is not in the way? This phenomena only happens when light passes through a convex lens.
When I shine a torch at a wall there is no cross-over of the beam and the light rays from the top of the torch hit the top of the wall and vice-versa for the rays from the bottom of the torch.

In order to produce both the moon's shadow and penumbra the sun, if 93million miles away, would have to be light years in diameter. The actual observed shadow and penumbra could only be made from a very much smaller sun much closer as shown in the top drawing with the light rays converging. Even in this scenario the penumbra would be the same size as the moon.
 
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rod

Oct 22, 2019
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Interesting post #41 by Pies. My observations here. Last evening I was out in my pastures looking at the First Quarter Moon and Sun. First Quarter Moon took place on 20-Jan-2021 at 2102 UT or 1602 EST. I was out at 1620 EST or 2120 UT. Using tools I have, the Moon's altitude a bit more than 50 degrees, azimuth > 134 degrees, close to 135 degrees. The Sun altitude a bit more than 8 degrees, azimuth a bit more than 235 degrees at my location (something not provided in Pies comments in this discussion for their observations). We also have the Jovian moon shadow eclipses at Jupiter that I observe regularly using my telescopes. Io and Ganymede for example cast their shadows on Jupiter as they orbit, these are solar eclipse events at Jupiter and easily observed in quality telescopes. Our Moon solar eclipse events work the same here on Earth as they do on Jupiter. Jovian moons cast their shadows on Jupiter, our Moon does the same here orbiting Earth.

What do you think I should see about the Moon and Sun last night using the Sun's rays shining on the First Quarter Moon, and there different altitude and azimuth settings at my location?

Concerning Jupiter, do the Galilean moon eclipse events work the same as here on Earth with the same Sun shining in the solar system?

Do you believe in Black Sun as the cause of a total solar eclipse of the Sun we see here on Earth?

One comment I do note here. Pies said "In order to produce both the moon's shadow and penumbra the sun, if 93million miles away,"

This sounds like during a total solar eclipse, the Sun has a penumbra cast on Earth (but this may be referring to the Moon's penumbra). It looks like to explain a total solar eclipse, Pies must have the Sun very close to the Earth and much smaller too. These interesting physics need to work at Jupiter.

One more note. Perhaps Pies can show the geometry and metrics used in their model for a closer Sun to Earth and the 21-August-2017 total solar eclipse across the USA. Many observations were made including detailed geometry of the umbra and penumbra size for the Moon crossing the USA as well as images taken by the ISS. I also observed this event but in any area had 81% coverage using my telescope with glass, white light solar filter.

The comment was "The actual observed shadow and penumbra could only be made from a very much smaller sun much closer as shown in the top drawing with the light rays converging. Even in this scenario the penumbra would be the same size as the moon."

We can test such a claim using the 21-August-2017 total solar eclipse event across the USA and also test at Jupiter too. We have many observations and measurements for these events in astronomy.
 
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I am not an astronomer and cannot comment on your own observations of other planets.
Regarding your observation of the moon and the sun's positions can you state what the 'angle' of the moon's illumination was at? Was it possible to 'draw' a straight line that was perpendicular to the moon's illumination back to the sun?

The attached drawing shows the earth and moon drawing to scale. How is it possible for the sun 93million miles away create a penumbra shadow of the moon on the earth?

All the diagrams that I have been able to locate are basically like the second drawing. For obvious reasons they cannot be drawn to scale and therefore create a false explanation of a solar eclipse. I searched to see if I could find out the diameters of a typical solar eclipse moon shadow and penumbra but couldn't find one anywhere. Is there any information like that from the 21 August 2017 eclipse?
 
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rod

Oct 22, 2019
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You need specific tools to measure the angles for the First Quarter Moon and setting Sun I observed. One tool shows the Moon at 1620 EST or 2120 UT, just past First Quarter was 50.2% illuminated and elevation angle above 50 degrees. Here is an interesting report on the August 2017 total solar eclipse you may enjoy. https://astronomy.com/great-american-eclipse-2017/articles/2016/06/25-facts-about-the-2017-solar-eclipse

Using your diagrams, how close to Earth must the Sun be for the Moon's penumbra shadow to be cast on the Earth during a solar eclipse event? I would like your min and max distances that the Sun is from earth here.

In the astronomy magazine report I showed the link too, which if any of the 25 facts listed about the total solar eclipse do you reject?
 
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All the diagrams that I have been able to locate are basically like the second drawing. For obvious reasons they cannot be drawn to scale and therefore create a false explanation of a solar eclipse. I searched to see if I could find out the diameters of a typical solar eclipse moon shadow and penumbra but couldn't find one anywhere. Is there any information like that from the 21 August 2017 eclipse?
That drawing is a nice one that demonstrates accurately what is happening.

The Sun emits light in all directions. The penumbra comes from any extended object (disk; non-point source). Draw, or follow, the lines from the solar limbs (edge) and you will see how some of these rays will cross and form that penumbral shadow.

Changing the scale to actual will only change the size of the umbra and penumbra.
 
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rod

Oct 22, 2019
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The key is how close must the Sun be to earth to explain the Moon's penumbra measured? Pies is clearly arguing for a much smaller Sun and much closer to Earth than the heliocentric solar system allows as well as spherical Earth size measurements.
 
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I'm really sorry but I cannot visualize exactly what you saw. I asked if you draw a straight line perpendicular to the moon's illumination back to the sun? Could you have done this?
The link you gave to the August 2017 didn't mention the diameters of the shadow or the penumbra. This would be very useful in drawing the phenomena to scale.
 
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Another thought is to consider what an observer sees. Those that are in the umbra see no solar disk. But as one moves away, then part of the solar disk will be exposed. Yet this is only partial light, hence it is dimmer as is found in the penumbra area. Once one moves far enough, then the full disk is seen and there is no shadowing effect.

But if the Sun were a point source then an observer would either see an eclipsed Sun (100%) or no eclipse, so no penumbra.
 
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rod

Oct 22, 2019
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Pies in post #47 did not answer about the 25 facts in the astronomy magazine report but is correct about sizes or diameters for the Moon umbra and penumbra on Earth during a total solar eclipse. Using Pies scale, what is the min distance of the Sun from Earth and what is the min size of the Moon's penumbra?
 
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With respect I disagree. If you extend the sun's rays from the moon/earth 93million miles back to the sun they will be virtually parallel and therefore could not create a penumbra. To create a penumbra there would have to be non-parallel light rays which is not possible at a distance of 93million miles.
 
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