[False] Claim that Scale Model of 2017 Eclipse Disproves the Heliocentric Model

[jumboseafood]

This video made a model of the 2017 eclipse on claimed its impossible on a globe. They results of the expermeint lead the moon to set in the east and the ecplise only lasted three hours.

Source: https://www.youtube.com/watch?v=0XvIH1f1qkM


Heres the set up and the size graph







Heres the sun setting in the east





And here is three hours later with the shadow pass the earth




Heres the third hour with the shadow pass Earth.

 

[Mick West]

If your model does not match reality, then something is wrong with your model.

I'd actually encourage people to do experiments like this. It can give some perspective on the actual relative sizes and distances in the solar system (and then it's fun to try to extend it to the nearby stars, which are amazingly far away).

So here the challenge is twofold: firstly to spot the mistakes in this model (or the interpretation), and secondly to come up with a more accurate model.

I might give it a go later today.

 

[Mendel]

I'm seeing the support for the "Earth" tilted at 1:50 and thereafter.

The 5 hour duration is correct:

https://en.m.wikipedia.org/wiki/Solar_eclipse_of_August_21,_2017
but obviously it starts when the moon's shadow starts to touch Earth; the experiment begins with the moon already on the Earth, which is wrong for this analysis. To see the full 5 hours, the shadow must transit completely, from start outside to finish outside.

The rationale for starting inside Earth is given at 1:30.

Note that this references the times with respect to a single point of observation, and that the total duration is under 2 hours and no longer 5 hours. This is the greatest failure.
Also note that the penumbra is already halfway across the globe at this time: people in the central spot on that globe would just see the model eclipse begin at this time. This cut the eclipse path in half.

The modelers are not clear on whether they are observing the core shadow (umbra/total), or the fringe (penumbra/partial); in the scale model, I expect the umbra is much too big compared to reality, and the penumbra is too small (and they're not paying any attention to it anyway). This is a result of them not modeling the sun correctly. If you model the observation from a single point, that is obviously quite sensitive to getting these sizes correct.

They do not show the light source in the video. If the light comes from a near point light source, it is not (near) parallel, as the sun's rays are, and moving the moon with respect to this source will move the moon's shadow more than it would if the light was parallel, coming from a far sun.

Have I overlooked anything?

 

[Z.W. Wolf]

I think you've covered it. I can't make heads or tails out of why they are starting with the Moon's shadow where it is. That thick accent with the echo effect isn't helping.

Something about the Earth being at zero degrees position and the Moon being at zero degrees position and the time the eclipse started. ???

 

[Mendel]

I think you've covered it. I can't make heads or tails out of why they are starting with the Moon's shadow where it is.

It looks like they wanted to track a single observation point, the one they have the data for, and since for that point, observation can only begin once the sun rises at 16:46 local time. Since the eclipse ends at 17:47, they were unable to disprove the globe with their misunderstood model with that data. Their misconception most likely is "the eclipse ends when the shadow leaves Earth", whoch is not true if you are considering an observer on the surface. Someone probably told them that if the're looking at when the shadow leaves Earth, they should take the 5 hour time, but they didn't completely understand why and did not adjust the beginning correspondingly, nor drop Earth's rotation. That they modeled Earth rotation is another indicator that they originally had an observer on the surface in mind.

 

[Z.W. Wolf]

The shadow is slightly to the west of the Earth because the eclipse started at 15:55 UTC, or 10:55 local time in the morning.

Content from External Source

Wut

Obviously the eclipse starts when the shadow first touches the Earth. So they're saying the shadow suddenly appeared on the surface of the Earth at that point at 15:55 UTC?

 

[Mick West]

For some perspective, here's the actual 2017 eclipse seen from a million miles away - essentially from the perspective of the sun.

Source: https://www.nasa.gov/image-feature/goddard/2017/nasas-epic-view-of-2017-eclipse-across-america

And here's a simulation done before the event, predicting what would happen from this perspective


And the same simulation from the perspective of the moon (or rather, a point far behind the moon, but continually aligned with the Earth.

 

[Z.W. Wolf]

Okay, so they're considering what a single observer would see from the surface of the Earth? This is such bizarre logic.

And they're not discriminating between partial eclipse and totality.

 

[Z.W. Wolf]

Here's my thread. https://www.metabunk.org/threads/cl...he-solar-eclipse-disproves-sphere-earth.8995/

Sadly the GIFs are dead.

Here's a proper model
Source: https://youtu.be/3FBlR_5dCt0

 

[Mendel]

Okay, so they're considering what a single observer would see from the surface of the Earth? This is such bizarre logic.

It'd have been nice if they had pulled it off. If you use their setup with a mirror ball, mark the observation spot, get the size of the umbra and penumbra correct, you can probably do it. You need to have a mobile camera that takes a picture of the "sun" as mirrored in the observation spot, and you're going to need to reposition the camera as you move the mirror ball, but then you ought to be able to take a bunch of eclipse pictures that look like the real thing with your model indicating the proper angles at each time.

 

[Z.W. Wolf]

I found the GIF I made from the DelBoy 1967 video.

 

[Mendel]

And this is the video:
Source: https://m.youtube.com/watch?v=3FBlR_5dCt0


It's not hard to replicate.

What I would really like to see is a model of a FE solar eclipse that works as well as this one, ideally with two different observer positions.

 

[Mick West]

Note that this references the times with respect to a single point of observation, and that the total duration is under 2 hours and no longer 5 hours. This is the greatest failure.

I think their greatest failure is actually them saying "the Moon is setting to the East"


They seem to be confusing the position of the shadow on the Earth with the position of the moon viewed from Earth. Their model does not show this at all. The moon sets in the West just like it always does, because the rotation of the earth on its axis is much faster than the rotation of the Moon around the earth. The Eclipse does not change this at all, but it does create confusion in the shadow moving from west to east, which is a bit unintuitive, but should be understandable after seeing what the model does.

Really their model isn't that bad. They just don't understand what they are seeing.

 

[Mick West]

Here I've combined the NASA simulations with the actual footage in a synchronized 4K video.
Source: https://www.youtube.com/watch?v=Tjzdm-HkN74

 

[Z.W. Wolf]

I think their greatest failure is actually them saying "the Moon is setting to the East"


They seem to be confusing the position of the shadow on the Earth with the position of the moon viewed from Earth. Their model does not show this at all. The moon sets in the West just like it always does, because the rotation of the earth on its axis is much faster than the rotation of the Moon around the earth. The Eclipse does not change this at all, but it does create confusion in the shadow moving from west to east, which is a bit unintuitive, but should be understandable after seeing what the model does.

Really their model isn't that bad. They just don't understand what they are seeing.

Yes, the shadow of the Moon on the Earth's surface and our view of the Moon in our sky are somewhat related but not in the simple way they seem to think. They're confusing the position of the Moon in our sky with the question of whether or not it would be eclipsing the Sun.

First of all, they're not keeping track of the two different motions - Earth's rotation and the Moon moving in its orbit. I addressed that issue in this post: https://www.metabunk.org/threads/cl...lipse-disproves-sphere-earth.8995/post-209653

Source: https://youtu.be/p7ZR1p-Uwy0

If one of those travel trailers we see in this video were in motion to our left, it would still disappear off to our right as we ride the merry-go-round.

And if we are just considering the shadow the trailer would cast on the merry-go-round as it blocked our view of the setting Sun... that's another layer.

 

[Mendel]

I think their greatest failure is actually them saying "the Moon is setting to the East"
[...]
Really their model isn't that bad. They just don't understand what they are seeing.

The moonset thing is wrong, but it doesn't have any effect on their conclusion and thus no effect on why the experiment failed.

What's the use of modeling the sizes of Earth and moon exactly if you fail to consider the sun and then fail to consider the size of the shadows? They made a model with a rotating Earth, but no observer position, and a support for Earth that apparently changed Earth's position as they rotated it. There is not a single parameter of the actual eclipse that you can model anywhere near accurately with this. If they had marked an observer position, they could have seen the moon shadow overtaking the observer eastward, but their decision to start with an observer in a sunrise position that was WRONG (because the umbra had already passed the position, while the table with the times said that was yet to come) meant that they couldn't have seen that since the shadow already started out east of the observer.

This commingling of the external frame of reference and the observer frame of reference, of never understanding what this model means for the observer on Earth, is the failure, and not understand moonset is just one symptom of that.

I'd generalize that many FEers generally have a hard time with spatial reasoning, and also have a hard time admitting that they do, and addressing it. Use of a tangible model is basically a good approach to address this, but if they can't mentally or physically put themselves in the observer position, it is not sufficient.

 

[Z.W. Wolf]

15:55 UTC = 10:55 a.m. local time?

The leading edge of the Moon's penumbra first touched the Earth's surface on the surface of the Pacific Ocean somewhere to the west of Oregon at 15:55 UTC, and first touched the Oregon coast 10 minutes later at 16:05 UTC. This was 8:55 a.m. PDT and 9:05 a.m. PDT respectively in Oregon.

So why are they saying 15:55 UTC equals 10:55 a.m. local time? That would be the local time in the Central Time Zone.

Here's what I think. The longest ground duration of totality was 2 minutes 41.6 seconds just south of Carbondale, Illinois... which is in the Central Time Zone. They seem to think that's where the eclipse physically started.

(Partial eclipse started there at 11:52 a.m. CDT or 16:52 UTC. Totality started at 1:20 p.m. CDT or 18:20 UTC.)

They are muddling the area where the partial eclipse first started on the Earth's surface (in the Pacific) with the area of greatest totality (Illinois). And they start the 5 hour clock by placing the model Moon's shadow where they fancy Illinois would be on their model Earth at 15:55 UTC.

Suffering succotash.

And...
-They're not distinguishing between penumbra and umbra.
-They do not take into account that 15:55 UTC is when the leading edge of the penumbra first touched the Earth's surface and 21:04 UTC is when the trailing edge of the penumbra left the Earth's surface.
-The penumbra and umbra in their model do not match those in the real world, so how could they place the leading or trailing edge of the penumbra accurately on their model Earth?

 

[Mendel]

15:55 UTC = 10:55 a.m. local time?

The data table shows a 16:46UT sunrise, so the data isn't for there. The coordinates in the upper left corner are 39°54'35.05"N 171°02'06.56"W, which is less than an hour off the international date line in the ocean, would that fit?

 

[Z.W. Wolf]

This is where the leading edge of the penumbra first touched the Earth's surface at 15:55 UTC. Local time was 3:55 a.m. standard time. I'm assuming there's no DST in that spot in the Pacific. Certainly not 10:55 a.m.

(This would be pre-dawn twilight locally.)



In any scenario it should be obvious that the shadow of the Moon couldn't just blink on at the spot on the Earth they show, without having moved across the Earth's surface west of there. It obviously had to do so on their model. They are just editing that out by starting the model Moon too far along its orbit. Why?

As I said, they seem to have chosen the area of maximum totality - in Illinois - as where the eclipse started. Mixing up two distinctly different things. And muddled a number of other things as listed above.

A total, bloody washout, as Basil Fawlty would say.

 

[jumboseafood]

It looks to me the eclipse only lasted for four hours in the model why is that?

 

[Z.W. Wolf]

This is a proper model. The Moon's shadow can't just suddenly appear where they show it in their model.


Source: https://i.imgur.com/rVyyfNI.gifv



And in regard to the Moonset issue.

The marks on the model Earth represent approximately where the west and east coasts of the U.S. would be. At this point the Moon's shadow is no longer on the Earth's surface. But it should be obvious that the Moon would still be in the sky on the east coast.



At this point, the Moon would be setting in the WEST on the east coast of the U.S.



At this point, the Moon would be below the western horizon on the east coast of the U.S. It would be getting low on the western horizon on the west coast of the U.S.


It would be a new Moon and not easily visible.

 

[Mendel]

No, if the sunrise is minutes before the total eclipse is seen, the location is close to where the umbra touches down.Viewed from the sun, at sunrise the observer is on the left edge of the ball, and if the umbra is outside of that, it must be outside the ball, only to enter it shortly. But if the plan was to model only the umbra travel, then the expected result should have been 3:13h and not 5.

 

[Z.W. Wolf]

That's right.

Restated: They're defining the total duration of the eclipse as 5 hours (and 17 minutes). Physically that time would start when the leading edge of the penumbra first touches the surface of the Earth and end when the trailing edge of the penumbra first leaves the surface of the Earth. The actual penumbra was quite large. See the videos presented by MW earlier in this thread.

The penumbra can first touch the surface during local twilight.

But their model does not have a penumbra of the proper size, because they have not modeled the Sun correctly. They say this doesn't matter, but it does. The real penumbra covered a large area. If they insist the duration was 5 hours they have to show a penumbra of the proper scale size.


If you define the total duration as starting when the umbra first touches the surface of the Earth and ending when the umbra leaves the surface of the Earth, the duration would be 3 hours and 13 minutes. Their model is more capable of showing this situation, but only roughly.

The umbra would first touch the surface of the Earth at local sunrise.

Summing up:

-The penumbra scenario would define the eclipse duration as 5 hours, 17 minutes.
-This scenario requires a properly to scale penumbra.
-They don't explicitly define the shadow in terms of umbra or penumbra.
-They don't have a properly modeled Sun and the Moon's shadow is sloppy, lacking a to scale penumbra.
-Despite this deficiency, they chose to define the eclipse duration as 5 hours.
-The scenario they are presenting is more in line with the umbra defined duration of 3 hours, 13 minutes, but this is only roughly possible to do.
-While presenting something like the umbra scenario, they go on to make a serious error in the umbra scenario. Somehow they think the Moon's shadow (umbra?) could first touch the daylight side of the Earth at 10:55 in the morning, local time, just jumping over everything to the west.
-Compounded errors make their conclusion meaningless.

(Why did you start your sentence with the word no? It sounds as if you're disagreeing with me.)

 

[Mendel]

The penumbra can first touch the surface during local twilight.

That is, at the very least, misleading?
https://en.m.wikipedia.org/wiki/Twilight (I forgot this was a book!)

Twilight on Earth is the illumination of the lower atmosphere when the Sun itself is not directly visible because it is below the horizon.

Content from External Source

At this point, the sun looks like someone took a sliver of a bit out of it:
(Lindsay Blum,
https://skyandtelescope.org/online-gallery/2017-total-solar-eclipse-phases-to-totality/ )
It can only look like that if you can see the sun at least peek above the horizon, since moon "bites" into the "leading edge" of the sun.

Content from External Source

https://en.m.wikipedia.org/wiki/Sunrise
So, like the umbra, the penumbra meets the Earth at local sunrise.

Your statement is technically not wrong, because at the time, the places west of the meeting point are in twilight, but the meeting point itself is experiencing sunrise.

-They don't have a properly modeled Sun and the Moon's shadow is sloppy, lacking a to scale penumbra.

And lacking a to scale umbra! Their umbra looks almost as big as their moon model. DelboY's model has a much smaller umbra, but its exact extent is hard to make out unless you are in an observer position on the ground.

(Why did you start your sentence with the word no? It sounds as if you're disagreeing with me.)

Because I don't agree that they intended to start at the point of maximum totality, in Illinois. (I should have expressed that more clearly.) I see no evidence for that anywhere, and I think at maximum totality, the shadow should be centered on the globe (as seen from the sun), and not off center, where they had it.

It is possible that they mixed up umbra und penumbra yet again, choosing the time when the umbra touched down, but placing the shadow where the leading edge of the penumbra was at that time.

 

[Mendel]

It looks to me the eclipse only lasted for four hours in the model why is that?

How did you reckon the four hours?

 

[Z.W. Wolf]

This is getting to be a pretty well beaten dead horse. I'm only speculating about why they decided the eclipse somehow began in the Central Time Zone. Your speculation might be correct or the real reason might be something surprising to both of us. The important thing is that it's obviously impossible.

Re: the penumbra and sunrise. This was surprising to me, but the fact is that the penumbra touched the Earth's surface at 39°54'35.05"N 171°02'06.56"W well before local sunrise. Now then, how is that possible?

Well, why do we have civil, nautical and astronomical twilight in the first place? Scattering and refraction. Sunlight is reaching the Earth's surface well before there is a straight line between the observer on the ground and the Sun. So you don't have to be able to see the Sun in the sky to already be inside the penumbra, because some of the light that would be scattered or refracted is being blocked and the twilight is darker than it would be. That's my thought process.

It's not valid to think of a shadow being scattered or refracted, but that makes one think of the nature of a shadow in the first place. There's no such thing as a shadow as a physical thing. There's only light. More or less light. A shadow is less light. Less refracted light is reaching the eye of the observer. So we think of that as being inside a shadow.

So, once again an invalid FE argument has made me think about something I would not have imagined otherwise.

 

[Mendel]

The angular diameter of the sun is ~32'. At sunrise, atmospheric refraction lifts the sun about 34' under normal conditions. (Rule of thumb: the lift is one diameter.) Nautical twilight puts the sun at -12° (and you'd need that to see the hour of time difference, the horizon refraction only gives you a few minutes).

"Twilight is produced by sunlight scattering in the upper atmosphere, illuminating the lower atmosphere so that Earth's surface is neither completely lit nor completely dark." (Wikipedia)

Re: the penumbra and sunrise. This was surprising to me, but the fact is that the penumbra touched the Earth's surface at 39°54'35.05"N 171°02'06.56"W well before local sunrise. Now then, how is that possible?

That's the start of the umbra path, the penumbra does not contact there first. (I understood you to have written that initially, apparently I misread?)

https://eclipse.gsfc.nasa.gov/SEdecade/SEdecade2011.html links to the NASA resources I'm using, the animation I posted above can also be found here.

The following table delineates the path of the Moon's umbral shadow during the Total Solar Eclipse of 2017 Aug 21 . [..]

[...]

Content from External Source

https://eclipse.gsfc.nasa.gov/SEpath/SEpath2001/SE2017Aug21Tpath.html
Note that the starting coordinates approximately match the ones we were discussing.

https://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/SE2017Aug21T.GIF
P1 is the penumbral touchdown point. It is closer to 30°N, 150°W.

The points P1 and P4 mark the coordinates where the penumbral shadow first contacts (partial eclipse begins) and last contacts (partial eclipse ends) Earth's surface

Content from External Source

https://eclipse.gsfc.nasa.gov/SEplot/SEplotkey.html

tl;dr the shadow isn't refracted, the coordinates got mixed up

 

[jumboseafood]

I counted the times he moved the moon model so I might have miscounted

 

[Z.W. Wolf]

This is a side issue, but...

I knew that was the umbral path. But, I see what you're saying. P1 intersects the umbral path... but farther east than I thought. And now I can picture why. It's P2 that intersects the umbral path at its western end, not P1.

But... I'm still going to insist that the twilight area west of the leading edge of the penumbra, all the way to the farthest extent of astronomical twilight, is going to be darker than it would be normally. It has to be.

And the leading edge of the penumbra is advancing east while the terminator is advancing west. So twilight to the west of the terminator is going to grow darker as the penumbra advances east. There's going to be less light in the atmosphere to the east. (As well as north and south as the diameter of the penumbra grows.)

BTW, twilight is the result of both scattering and refraction. Refracted light is scattered. Scattered light is refracted.

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter19/twilight.html

 

[Mendel]

I counted the times he moved the moon model so I might have miscounted

In the first motion segment, he announces times with the movement of the Earth, which he later drops. You can see a pointer on the Earth gear in the overhead shot inlay in the lower right corner, and the 15° marks correspond to a full hour. At 6:20 it's 8 am, and I think I can see a sliver of penumbra shading the ball; 7:00/9am thenshadow is well on. At 9:40/1pm (13:00h) the shadow is half off, and at 2pm it is fully off. If you go from 9am to 1pm, that is only 4 hours, but since the shadow isn't off the ball at either point, you also need to add the time for it getting on and off, say 45 minutes extra for the start of the eclipse and 30 minutes for the end? That brings the total to 5:15.
Another way to look at it is that the umbra (which feels too big) is still almost off at 9am and already off at 1pm, so the total eclipse lasted less than 4 hours on the model, and the real duration was 3:14. Now consider that the real path was slightly shorter because it didn't cross the equator, and it kinda fits. (The Earth also moves ~0.2° with respect to the sun, not sure if that was factored into moon motion, if not, you have an error of ~24 minutes.)