Okay, thanks for the explanation. I have another question. Why is it that the shadow cast by the moon on the land is only between 50 and 100 miles wide?
Since the moon is supposedly 2,159 miles wide, it should cast a much wider shadow.

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The size of the umbra varies from one eclipse to another mostly due to how close the moon is to the earth each time. The distance from the earth to the moon is constantly changing since the moon's orbit is not circular but rather it's elliptical or parabolic, really. Kind of like a hula hoop being twirled around your waist.
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That's the umbra, or the totally dark area of the moon's shadow. If the moon were further away from the earth this time, the umbra would be smaller. And if it were far enough away, there would be no umbra at all because its total shadow would reduce to a point before it reaches the earth's surface. That's what happens when we have an "annular" eclipse, when the sun is seen as a ring all around the moon.
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This time, I expect many thousands of people viewing this "Great American Eclipse" to see the "Diamond Ring" effect, when just before totality, one speck of the sun's perimeter keeps shining through some crevice or valley of the moon's surface and everyone sees the circular center which is the shape of the moon, looking like the open space in a ring where you put your finger, but the sun's shine splays out in one place on the "ring" as if it were a huge diamond mounted there.
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The width or diameter of the moon casts a shadow toward earth that has a two-aspect conical shape. One cone is the total darkness where the sun is totally covered by the moon, and this shadow gets smaller the further away from the moon you go. The open end of the cone is the perimeter of the moon where the light side of the moon (lit by the sun) transitions to the dark side of the moon (in the shadow side). The point of this cone is the very end of the moon's shadow where a viewer would see the sun emerging all around the moon.
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The other cone is one where the moon itself is the point end as it were, and the cone gets wider moving away from the moon and away from the sun. This is what people on earth will see when they are far from the total eclipse path, as far away as in South America where the moon will only obstruct some small portion of the sun, like 1% for example. Beyond that point, where the moon obscures nothing of the sun, is outside this second conical shadow.
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I don't really like this picture because it does not show the shadows accurately considering the displayed size of the sun. It's not to scale so you have to imagine the sun much further away for this to make sense. Think of the sun about 10 feet to the left and it's a little closer to reality, however that's just an approximation because the sun is much larger than that and much further away, but perspective wise, this size and 10 feet isn't too bad. The point is, the top line of the umbra should be pointing at the top edge of the sun. Likewise, the top edge of the earth's shadow should be pointing at the top edge of the sun, too. But this is just for the sake of names, where it shows the umbra (full shadow) and the penumbra (partial shadow). 
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Here is another picture, with a little different style:
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They admit the diagram is not to scale! That's correct!! 
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The sunlight appears to be coming in parallel lines (they're not actually parallel but they APPEAR to be). That's why the moon's penumbra appears to be a cylindrical shape, when in fact it is a conical shape with the moon at the small end of the cone. Likewise, the earth's shadow (not shown here) is conical too, with the earth being at the small end of the cone and the cone getting larger as one moves away from the earth on the shadow side away from the sun.
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The size of the umbra varies from one eclipse to another mostly due to how close the moon is to the earth each time. The distance from the earth to the moon is constantly changing since the moon's orbit is not circular but rather it's elliptical or parabolic, really. Kind of like a hula hoop being twirled around your waist.
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That's the umbra, or the totally dark area of the moon's shadow. If the moon were further away from the earth this time, the umbra would be smaller. And if it were far enough away, there would be no umbra at all because its total shadow would reduce to a point before it reaches the earth's surface. That's what happens when we have an "annular" eclipse, when the sun is seen as a ring all around the moon.
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This time, I expect many thousands of people viewing this "Great American Eclipse" to see the "Diamond Ring" effect, when just before totality, one speck of the sun's perimeter keeps shining through some crevice or valley of the moon's surface and everyone sees the circular center which is the shape of the moon, looking like the open space in a ring where you put your finger, but the sun's shine splays out in one place on the "ring" as if it were a huge diamond mounted there.
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The width or diameter of the moon casts a shadow toward earth that has a two-aspect conical shape. One cone is the total darkness where the sun is totally covered by the moon, and this shadow gets smaller the further away from the moon you go. The open end of the cone is the perimeter of the moon where the light side of the moon (lit by the sun) transitions to the dark side of the moon (in the shadow side). The point of this cone is the very end of the moon's shadow where a viewer would see the sun emerging all around the moon.
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The other cone is one where the moon itself is the point end as it were, and the cone gets wider moving away from the moon and away from the sun. This is what people on earth will see when they are far from the total eclipse path, as far away as in South America where the moon will only obstruct some small portion of the sun, like 1% for example. Beyond that point, where the moon obscures nothing of the sun, is outside this second conical shadow.
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I don't really like this picture because it does not show the shadows accurately considering the displayed size of the sun. It's not to scale so you have to imagine the sun much further away for this to make sense. Think of the sun about 10 feet to the left and it's a little closer to reality, however that's just an approximation because the sun is much larger than that and much further away, but perspective wise, this size and 10 feet isn't too bad. The point is, the top line of the umbra should be pointing at the top edge of the sun. Likewise, the top edge of the earth's shadow should be pointing at the top edge of the sun, too. But this is just for the sake of names, where it shows the umbra (full shadow) and the penumbra (partial shadow).
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Here is another picture, with a little different style:
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They admit the diagram is not to scale! That's correct!!
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The sunlight appears to be coming in parallel lines (they're not actually parallel but they APPEAR to be). That's why the moon's penumbra appears to be a cylindrical shape, when in fact it is a conical shape with the moon at the small end of the cone. Likewise, the earth's shadow (not shown here) is conical too, with the earth being at the small end of the cone and the cone getting larger as one moves away from the earth on the shadow side away from the sun.
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No, that doesn't work at all. There is no "cone." That's not how light works. I did a little experiment this afternoon, and the shadow was the same size as the object that I put between the flashlight and the surface on the other side of the object. Light does not travel the way you have described it.

Thanks happenby. The only "truth" I've rejected, of course, is doctrine according to the Church of NASA.
I think that Neal may have a more difficult time explaining the issue of the shadow cast by the moon during the eclipse, as this has already been discussed in a good pro-flat earth video, here:

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This is a great example of how ignorance can produce nonsense. This video is full of misunderstanding and convoluted contradiction. So it's nice to see that this eclipse is rattling the cage of flat-earthers. Because they can't predict its course using their model, and with their preconceived wrong idea, they cannot fathom to comprehend what is happening. Every which way they're off course. It would take PAGES to comment on all their mistakes in this video.
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The post I made above gives an idea of the two kinds of shadow the moon will cast, and the two kinds of view people on earth will see. I will be in Los Angeles, where about 50% of the sun will be covered by the moon. That puts us in the penumbra (not the umbra), and many shadows under trees and the like will show images of the eclipse in the sky like this:

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This is a great example of how ignorance can produce nonsense. This video is full of misunderstanding and convoluted contradiction. So it's nice to see that this eclipse is rattling the cage of flat-earthers. Because they can't predict its course using their model, and with their preconceived wrong idea, they cannot fathom to comprehend what is happening. Every which way they're off course. It would take PAGES to comment on all their mistakes in this video.
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The post I made above gives an idea of the two kinds of shadow the moon will cast, and the two kinds of view people on earth will see. I will be in Los Angeles, where about 50% of the sun will be covered by the moon. That puts us in the penumbra (not the umbra), and many shadows under trees and the like will show images of the eclipse in the sky like this:

Complete nonsense, Neal. Goodnight.

Complete nonsense, Neal. Goodnight.

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The image I posted isn't fake. It's just a photograph someone posted of the ground during an eclipse. There are hundreds of photos like this. I know they're accurate because I have seen this effect in person. Anyone who watches for shadows during an eclipse will see this sort of thing on the ground and building walls all around them, unless the sky is cloudy or very smoggy or full of smoke, etc.
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Here are some more photos:
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That's on the siding of a house, from the shadow under a tree during an annular eclipse.
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This one is on a fence, showing a partial eclipse shadow under tree branches.
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You can do this with your fingers against a wall -- just don't look at the sun!!
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This one is using binoculars. Just be sure not to LOOK through them!!

The width or diameter of the moon casts a shadow toward earth that has a two-aspect conical shape. One cone is the total darkness where the sun is totally covered by the moon, and this shadow gets smaller the further away from the moon you go. The open end of the cone is the perimeter of the moon where the light side of the moon (lit by the sun) transitions to the dark side of the moon (in the shadow side). The point of this cone is the very end of the moon's shadow where a viewer would see the sun emerging all around the moon.
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Maybe I wasn't clear enough -- the two shadows cast from the moon are CONCENTRIC, meaning one is inside the other. They are not side-by-side. The outside shadow is fuzzy and fades away at the edges, while the inside shadow is more distinct, but it too has a blurry boundary. Some diagrams make them appear sharp and crisp but that's just an easy way of depicting a picture that is very difficult to describe. To show it accurately would make it very hard for the viewer to understand because the image is inherently blurry. So for clarity's sake they make the image sharp, but ironically, that makes it inaccurate.
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One more thing about the movement of the sun and moon during the eclipse.
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There are two ways of thinking about what you see. One is, that the moon is "still" and the sun is going behind it. The other is that the sun is "still" and the moon is moving in front of it. But the reality is both are moving. You have to think about this before the eclipse happens, because if you wait until it's happening it's too much to think about all at once, and you'll be confused.
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When you realize both are moving in the same direction, then you can observe that the sun is moving faster. It's passing up the moon, with the moon in front and the sun behind it. Kind of like you're walking along a highway and look across the road to see a shiny white car passing a slower black car that's in the right lane. For a moment, the shiny car is hidden behind the black car, and then emerges on the other side. They're moving from left to right. But if you think that the sun is "still" and the moon is moving by, then it appears that the moon is moving from right to the left. So it makes a lot of difference how you're thinking while you watch. That's why it's so important to observe objectively, without prejudging what you expect to see.
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Another very interesting phenomenon is Shadow Bands.

They look like this, but more like the surface of water, rippling. Very strange.
Meteorologists do not all agree what causes them or what they are, but they occur only immediately before the total eclipse, they move over the ground at about 5 mph, you have to run to keep up with them, they wave around like they're being projected onto the ground (which they really are!) and then they disappear as mysteriously as they appeared.
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This shows how uninteresting it can turn out when you try to be scientific. The photo doesn't do justice to shadow bands which are really very interesting. I think you need to have a motion picture of them because their movement is very mysterious.
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Perhaps some mysterious scenery would help! 
Here are shadow bands photographed in Egypt!!
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Neal,

I do appreciate the information you've posted, and I do understand what you're saying about the shadow - in that the outer edge may not be visible due to it not being an obvious shadow. But in the video that I posted last night, there was a NASA photo featured which clearly showed that a clear shadow was only about 50 miles wide during a past eclipse. There was no wider shadow that was dim or clouded or mottled. I hope you won't be offended that I cannot accept your evidence, because it doesn't really prove your point regarding the shadows.

The video I posted last night probably does contain errors. The fellow who made it is not a scientist - he only wants to understand reality. However - he makes a very important observation: SCALE.

You yourself mentioned that the model pictures you provided are not to scale, and here's why I think this is extremely important. Your pictures cannot be accepted, due to their inaccuracy, because of scale. I've tried to find pictures of a true rendering of scale in a picture of your heliocentric system, but couldn't find any on the internet, and here's why I think that they may not exist. If a true-to-scale picture were made of your heliocentric system, then it might render that system absurd, because it would then be apparent that in the heliocentric system, the earth is so far away from the sun, that the earth couldn't possibly "rotate" around the sun every 365 days.

The cozy heliocentric system, as depicted in the models that we all grew up with - you have to agree that the models are wrong.

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MY "heliocentric system?" When did I say I agree with that? Don't bother looking because I never said I support it. You and others keep accusing me of that but it's a good example of your continual misrepresentation of all kinds of things. As often as I have explained this and that, you keep getting it wrong. Why should I keep trying? It's like beating a dead horse.
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The simple reason that accurate scale is not shown is that you wouldn't be able to see anything. The sun would be a dot on one side of the page and the earth and moon would not be visible on the other side of the page. So how can a picture that doesn't show anything be of any help? The size of the sun, moon and earth are exaggerated so that you can SEE SOMETHING and the parts of the subject can be identified. Just because the reality is so distant and the parts would appear so small on the page does not prove they're not possible. If you tried to accurately depict the size and parts of an oxygen molecule on the page there would be nothing to see, because the nucleus would be tinier than a speck, and the electrons would be so small for any ink quantity to depict. Does that mean oxygen does not exist? Try showing a SCALE IMAGE of a person standing in New York City, and another person standing in Washington D.C., with the distance between them according to real scale and the size of the two people. NY would be the size of a nickle and DC would be the size of a dime, with 15 inches of nothing between them. The fact that you would not be able to see either person does not mean that nobody exists in either place.
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in the video that I posted last night, there was a NASA photo featured which clearly showed that a clear shadow was only about 50 miles wide during a past eclipse. There was no wider shadow that was dim or clouded or mottled. I hope you won't be offended that I cannot accept your evidence, because it doesn't really prove your point regarding the shadows.

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Any "clear shadow" from NASA is for illustration purposes only and not to accurately depict what is being discussed. Someone standing in the total eclipse shadow will have no question whether it is dark all around them, but just try to find the EDGE of that shadow. You will be able to see photos from airplanes after the 21st, no doubt, and it will be quite challenging to find the edge of the (dark) umbra shadow, labeled "Path of the total solar eclipse" in the image below. One reason for this is the fact of shadow bands. These are wavy cloud-like ripples on the ground that wave like a flag in the wind or the surface of water. From a distance, they have the effect of causing a DIFFUSION OR BLURRINESS to the edge of the shadow. For this reason alone, the edge of the total eclipse shadow will be impossible to identify. 
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There will be NO CLEAR SHADOW IN FACT. The eclipse shadow edges will be ANYTHING BUT clear.
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There are many images on the net that chart the varying degrees of penumbra (light or fading) shadow that will be visible all over the USA on the 21st. It is due to the partial coverage of the moon over the surface of the sun from various places......
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Take the 0.9 mag line, just below the path. Everyone on that line will see 90% of the sun covered, and will not see any shadow bands, nor will they see darkness as if it were night time with stars visible in the sky. They will be in a partial shadow, which will be less than daylight but still brighter than night time. Some animals might behave strangely like they think the sun is going down but birds probably won't roost and crickets won't start chirping.
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As you move further south, like the Rio Grande area in Texas or Mexico, the 0.7 magnitude shadow will be less dark with 70% of the sun covered. And so on. The further south you go the less dark the shadow, until eventually it will be no shadow at all. So it should be easy to understand, if you're paying attention, that the edge of the moon's penumbra shadow will not be something discernible by plain sight in real time.
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This same website has a very good image (NOT TO SCALE!!!) showing how the various parts of the sun, sunshine, moon, shadow and earth are made comprehensible. This is for illustration purposes, and not intended to depict the accurate sizes of these entities. There is no way to depict this stuff accurately by scale. No way whatsoever.
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That's just about as good as it gets illustration-wise. The lines of the edges of the sun's light are properly drawn out to show where they fall on the moon and earth along with the associated shadows. 
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Don't bother getting upset that the sun is larger than the earth in the bottom version but smaller than the earth in the top version. I won't be impressed. NOT TO SCALE is what it says: not to scale. The top one is a solar eclipse and the bottom one is a lunar eclipse. 
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Likewise, don't bother getting upset over "EARTH'S ORBIT" with the dotted line. They could just as easily have "Sun's orbit" with a dotted line and nothing else would change!! So that's not important here.
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Keep in mind that ALL PARTS OF THE SUN shine with comparable intensity, so that all around near the edges of the sun the light is just as bright as it is in the center of the sun, unlike your flashlight where there is a bright spot in the center and a less bright area all around the bright spot. Furthermore, all parts of the sun shine in ALL DIRECTIONS equally. The sun is not a searchlight but an omnidirectional beacon without peer in our experience. No wonder so many pagan cultures practice sun worship!! HAHAHA
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Neal said: MY "heliocentric system?" When did I say I agree with that? Don't bother looking because I never said I support it. You and others keep accusing me of that but it's a good example of your continual misrepresentation of all kinds of things. As often as I have explained this and that, you keep getting it wrong. Why should I keep trying? It's like beating a dead horse.

There are only two cosmological theories at odds here: geocentrism and heliocentrism.  There is no such thing as a geocentric ball earth theory in science. That is a very recent modern concept by those who figured out that the earth isn't moving.  So they invented a ball hanging in space too fearful to accept the geocentric model long ago shown to be true.  The problem with ball theory is that it is a hybrid of a lie by pagan modern science known as the heliocentric model. For those who think there is even a modicuм of truth to this theory, please explain how NASA is proven to lie about moving, rotating, barrelling earth, but isn't lying about it being a globe?