# Sun and Moon

Page 4 - Seeking answers about space? Join the Space community: the premier source of space exploration, innovation, and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.
Status
Not open for further replies.

#### Pies

That's not much of scientific explanation I would have expected something with more substance rather then indignant arm waving. All I am asking is why you cannot see a perpendicular direct line of sight between the moon's illumination and the sun.

#### COLGeek

##### Cybernaut
Moderator
That's not much of scientific explanation I would have expected something with more substance rather then indignant arm waving. All I am asking is why you cannot see a perpendicular direct line of sight between the moon's illumination and the sun.
You seem to be asking to prove a negative. No explanation, as many have been offered, seems to satisfy your query.

Maybe someone will come along who can explain in a different way.

#### rod

This link has some interesting info on the Moon's umbra size. Post #70 claims "Working backwards using the accepted diameter of the sun but keeping the same penumbra (twice the diameter of the moon) we get an umbra of 1117miles which is 7.5 times larger."

This is not surprising but the triangle solution has problems if you read the link I cited here. Spherical trigonometry for the shape of the earth is important too.

"How Large Is the Moon's Umbra?
The size of the area on the Earth's surface covered by the Moon's umbra during a total solar eclipse depends, amongst other things, on the Moon's current distance from Earth. The smaller the distance, the larger the umbra. If the Moon is at its closest to Earth (its perigee) during the eclipse, the Moon appears larger in the sky. In that case, the umbra's path across the Earth's surface typically has a width of roughly 150 km (90 mi) at the Earth's equator. At higher latitudes, the Sun's rays hit the Earth's surface at a shallower angle, so the umbra's size grows accordingly. During some total solar eclipses, the umbra's path width reaches over 1000 km (600 mi) at the poles."

Pies posts do not use formulas like this and Pies will not show what the arcminute size of the Sun should be or its distance as I cited in post #71. This means using Pies approach here, we cannot do real world testing of the claims presented for the angular size of the Sun, or its distance from Earth.

Last edited:

#### Pies

You seem to be asking to prove a negative. No explanation, as many have been offered, seems to satisfy your query.

Maybe someone will come along who can explain in a different way.
Absolutely not! I have not seen one explanation that can conclusively explain why. It is a simple torch and football analogy but nobody seems to be able to understand its simplicity.

#### rod

Pies, understand the simplicity of my question about my solar observations today and disclose your angular size for the Sun using your formulas and distance from Earth. We need real world testing now

#### Pies

Rod I don't know or understand what you are asking. The calculations for determining the diameter of the sum is just simple Pythagoras. Please look at my last two drawings and all the triangles are shown on them and all the lengths of the sides.
If you still don't understand I'll do another drawing to explain.

rod

#### COLGeek

##### Cybernaut
Moderator
A definitive source:

rod

#### rod

Pies, in post #81, no need for more drawings using triangles and Pythagoras. You may find this of value, https://en.wikipedia.org/wiki/On_the_Sizes_and_Distances_(Aristarchus)

This presents another ancient Greek method for measuring the size of the Sun and lunar eclipse. The *Results* table shows what you get and the modern values, side by side. Clearly different *solutions* result in different answers for the size of the Sun and distance from Earth

#### rod

FYI all. There is plenty of astronomy material on ancient Greek measurements for the Sun, Moon, and Earth. Some reading this discussion may find the links informative and the arXiv papers interesting reading.

'Estimating the Moon-to-Earth Radius Ratio with a Smartphone, a Telescope, and an Eclipse', https://ui.adsabs.harvard.edu/abs/2020PhTea..58..497C/abstract, October 2020. arXiv paper attached.

'Determination of the Sun's and the Moon's sizes and distances: Revisiting Aristarchus' method', https://ui.adsabs.harvard.edu/abs/2017AmJPh..85..207M/abstract, March 2017, "We have investigated the practicability of Aristarchus' method of determining the Sun's and the Moon's sizes and distances from Earth using a simple 8-in. telescope and a digital camera. Combining our astrometric observations made on October 20, 2012 with data from the lunar eclipse of June 15, 2011, and adopting a proper statistical approach, we obtain the two distances with errors of a few percent for the Moon and about 10% for the Sun. We also explain quantitatively why Aristarchus and his contemporaries, though able to measure the Moon's size and distance acceptably, could not be successful in determining the Sun's size and distance. Our experiment can be carried out in small semi-professional or amateur observatories and can be performed in an astronomy lab class."

Another interesting review, 'Outreach Testing of Ancient Astronomy', https://ui.adsabs.harvard.edu/abs/2015EPSC...10...40S/abstract, October 2015.

#### Pies

A definitive source:

I looked at the NSA link you provided and there was nothing on there about how the moon is illuminated. It does mention the diameter of the sun being 864,000miles but this conflicts with the maths using the sizes of the umbra and penumbra produced by a solar eclipse. You can check the maths yourself from the dimensions given in my drawings.

Regarding my question about the direction of the moon's illumination has not been answered. One paper that was offered said it was an illusion cased by light bending in the celestial sphere. I pointed out that the celestial sphere is just a construct to make it easier to conveniently 'observe and describe' the sky. It doesn't actually exist. Another suggestion was creating a triangle between the moon, sun and the observer. Again I pointed out the position of the observer will not change the path of the sun's light rays to the moon.

At this moment in time nobody has agreed that the light from the sun shining onto the moon is the same as light from a torch shining onto a football. I can only guess that is cognitive dissonance.

There is another fact that nobody like to address and that is when there is a full moon the light falling on it from the sun is evenly distributed across its whole disc. If the moon is a sphere then this is not possible. It will be brightest at the centre and gradually fall-off towards the edges. This is because the reflected light changes as the curve of the moon changes as the angle of incidence equals the angle of reflection and as you move towards the edge of the moon you will see less and less reflected light. In other words there would be a 'hot-spot' in the middle of the moon. What is observed is a 'flat' moon. I know you are not going to like this but physics is physics - I didn't invent them. Here is Youtube video explaining how light behaves when falling on sphere.

Also see attached image.https://www.dropbox.com/s/13s9yyjay3ah4h4/Reflected light.jpg?dl=0

#### COLGeek

##### Cybernaut
Moderator
You have questioned the size of the Sun. You now seem to imply that the Moon is "flat".

You are also on the verge of insulting others using terms such as "cognitive dissonance".

I think this thread has run its course. Good luck @Pies on your endeavors, whatever they may be.

#### Pies

I'm not implying anything! Explain to me why the moon's illumination does not appear to show that it a sphere?
Do you actually know what cognitive dissonance is?
With respect you do not like having your belief system challenged by evidence.

#### COLGeek

##### Cybernaut
Moderator
I'm not implying anything! Explain to me why the moon's illumination does not appear to show that it a sphere?
Do you actually know what cognitive dissonance is?
With respect you do not like having your belief system challenged by evidence.
Belief and facts are not necessarily in alignment, as seems to be the case here. Have you ever observed the Moon with a telescope or binoculars? If so, you would see what is clearly a spherical object.

Your "evidence" is pure nonsense, from a factual perspective.

#### Pies

I ask you the same question - have you ever wondered why the reflected light does not obey the laws of optics.?
There is a definite conflict here that observation suggests it is a sphere but its physical properties suggest that it isn't.
Would you like to comment on the image I sent showing lighting on spheres? Surely you must have an opinion about the image!

#### COLGeek

##### Cybernaut
Moderator
I ask you the same question - have you ever wondered why the reflected light does not obey the laws of optics.?
There is a definite conflict here that observation suggests it is a sphere but its physical properties suggest that it isn't.
Would you like to comment on the image I sent showing lighting on spheres? Surely you must have an opinion about the image!
Seems you are the only one in this conversation that believes your opinion. No discussion nor presentation of facts/science seems to meet your standards, so I shall withdraw from this discussion.

Seems we are now entering the realm of "flat Earth", "flat Moon", simulation, hologram, imaginary conspiracies, etc. and that is not the purpose of this forum.

I wish you well in your beliefs and may you have good fortune. One last thing, try a telescope/binos as previously mentioned.

#### Pies

I agree that it might be best you leave this discussion since you have not actually offered any refutation of my DATA and FACTS. Basically calling me a 'conspiracy theorist' is no more than name-calling and appears to be your last line of defence.

I appeal to others on this forum to address my original question about the moon's illumination direction and its apparent non-spherical light distribution across its face.

If nobody wants to engage me in this then I will also bow-out.

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
As a scientist (B.Sc.) with any number of granted patents (which require scrutiny by scientists at the Patent Office) and as someone who has had an interest in astronomy and cosmology for about 60 years (yes, 60), I cannot agree more with COLGeek.

"Nothing but the Sun and some reflected light from Earth."
Of course, there is absolutely minimal illumination from stars, but I include this only in the interests of scientific completeness. Illumination decreases according to the Inverse Square Law. As distance increases by x, illumination decreases x squared. If the distance of the stars is millions of times further than the Sun-Earth distance (1 AU = Astronomical Unit), the illuminations are millions times millions of times less than Solar illumination.
This is proved by the fact that the illumination of the 'dark' side of the Moon by other stars is comparatively nil. Pedants may wish to consider illumination by interstellar dust. Same refutation applies.

*Quick conversion of light years to AU: 1 light year = 63241.07709 AU
Strictly the nearest star (other than the Sun) is approximately 1/4 million AU away.

Conclusion. My opinion is that intelligent people have spent far more time on this subject that it deserves.

Cat

IG2007 and COLGeek

#### Pies

As a scientist (B.Sc.) with any number of granted patents (which require scrutiny by scientists at the Patent Office) and as someone who has had an interest in astronomy and cosmology for about 60 years (yes, 60), I cannot agree more with COLGeek.

"Nothing but the Sun and some reflected light from Earth."
Of course, there is absolutely minimal illumination from stars, but I include this only in the interests of scientific completeness. Illumination decreases according to the Inverse Square Law. As distance increases by x, illumination decreases x squared. If the distance of the stars is millions of times further than the Sun-Earth distance (1 AU = Astronomical Unit), the illuminations are millions times millions of times less than Solar illumination.
This is proved by the fact that the illumination of the 'dark' side of the Moon by other stars is comparatively nil. Pedants may wish to consider illumination by interstellar dust. Same refutation applies.

*Quick conversion of light years to AU: 1 light year = 63241.07709 AU
Strictly the nearest star (other than the Sun) is approximately 1/4 million AU away.

Conclusion. My opinion is that intelligent people have spent far more time on this subject that it deserves.

Cat

With respect to your qualifications and age, I'm afraid that observation and maths have to trump them. You may see this as arrogance but I cannot help what I observe and mathematical outcomes. However I do accept what you say about the insignificance of starlight affecting the moon's illumination.

Here is a summary of what I have been posting with relevant links in case you haven't seen them.

1 The a.m. observed direction of the moon's illumination does not appear to line up with the observed position of the sun - the torch/football analogy.
https://www.dropbox.com/s/1idusvrkxhlaeyj/Drawing 4.jpg?dl=0

2 I used this link provided by a member of this forum https://astronomy.stackexchange.com...shadow-of-the-moon-on-the-earththe calculated
to calculate the projected diameter of the sun using the link's calculated diameter of the umbra and penumbra plus, the accepted diameter of the moon and the accepted earth/moon and earth/sun distances. The calculations would appear to show the sun's diameter to be 1.68million miles.

3 The illumination of the a full moon does not appear to follow the laws of reflected light from a sphere.

https://www.dropbox.com/s/13s9yyjay3ah4h4/Reflected light.jpg?dl=0

Last edited by a moderator:

#### Catastrophe

##### "Science begets knowledge, opinion ignorance.
Conclusion. My opinion is that intelligent people have spent far more time on this subject that it deserves.

IG2007
Status
Not open for further replies.

Replies
0
Views
166
Replies
22
Views
1K
Replies
0
Views
207
Replies
0
Views
202
Replies
18
Views
8K