Ok so you observe a point of light (your star) on the vertical and then you move a distance to the horizontal and then measure the apparent angle back to the point of light (your star) and you can tell the distance to that star....right?
Is this what you're saying?
Sort of yes, but you need to consider it as an isosceles triangle with the two longest sides reaching out to a star and you setting the shortest side by how much you move. If that is only tiny then the angle between the two observations is tiny. You can’t look at a star, say you have no idea of the distance then take a step to the left and say “oh now I can”. You need the base of that triangle to be as big as possible. The diameter of the earths orbit is the biggest distance we can achieve without space travel. See the link I provided, it goes into more details than I have just now.
If we could ever travel to Alpha Centauri, chances are we would change what we know of the scale of our galaxy. Likely not by a massive amount but by a few percent. Measuring that bigger change in angle would give greater accuracy.
The sun and the moon appear the same size. We are told it's because of the distances and sizes of them that just happen to coincidentally make them appear the same size.
Yet we are told the sun is nearly 1 million miles in diameter and at 93 million miles and the moon is supposedly just over 2000 miles in diameter and at 240,000 miles.
Soooo, like I mentioned before, how is the sun and the moon measured using trig if they appear the same size?
You need another event and multiple observations, such as a transit of venus to accurately measure the scale of the solar system. You can work out some details with lower accuracy during a lunar eclipse. I think I provided a link to it last week.
Let's do the simple one.
Show me how you calculate the moon and the sun, distance and size for both.
Go to basics and use the basic tools like the historical people used to do it.
How would you go about it to get these sizes and distances.
No. What is in it for me trying and failing again to explain something to you? Why not google it and try it for yourself.
Or how about two other challenges? As I went to the effort last week of providing an interactive model of a globe where the angle to polaris matches that of observations as you move further south, how about you tell me if that model matches observations and if not, why not?
The second challenge is, why don’t you tell us how you have calculated your distance to your dome? I’ve repeatedly provided explanations and working models, your turn.
However, if you mean astronomy as in looking at gaseous planets and rocky planets plus burning balls of fire in a space vacuum, then I don't really know what can be gained from that mindset but I can clearly understand why people would by that belief.
The issue comes right back to a telescope. Magnifying those points of light like a large microscope looking at what's on the microscope mirrored plate.
A single observation in a telescope will give you what you say, a single 2d image of something, same as looking briefly at a ship on a horizon through a telescope. What I have said a few times this morning is that astronomy is not just taking a quick glance at something once and producing all this data. It is about accurate observations recorded and correlated over time. E.g. my example of how Giuseppe Piazzi spotted an unrecorded object, determining over a short time frame that it was moving relative to other stars then over a longer period finding that could only be in a circular planetary orbit. He didn’t just nip out for a fag, glance in a telescope and say “Arrrh, that be an asteroid or may be per’aps a minor planet”. Astronomy does not work like that, it is not that simple and he was not from the west country. He couldn’t have a quick musing and invent what it was then pass it off as fact.
When investigated back further, Charles Messier had previously recorded it in another section of the sky 6 years earlier but dismissed it as he was only looking at comets, but his observational data helped prove what it was.
Back to the ship on the horizon, watch it for a bit and you will see it move, from that you will determine speed and direction. Continuation of observation is the key.
