Originally posted by Suzianne
Perfect. Kudos for thinking of this.
P.S. On the APoD site, the url you gave is always the current day's picture. So to come back to this picture on another day, you have to give the url as such:
where 160729 is the date -- year 16, month 07, day 29
In this way you can find the picture for any day of the year and cycle through them.
Yeah, I knew that but forgot about archives. That link only works for one day. Thanks for fixing that.
Did you know Isaac newton did work in optics that proved the impossibility of the flat Earth?
He did work on the density of the atmosphere and showed that due to the fact air is more dense close to the ground and less dense at altitude, when we have a relatively close horizon like we do now, the sun will set (and rise) as a sphere more or less. But with say a horizon 10,000 miles away, 16,000 km or so, the densities add up to make a very distorted image of a setting sun, flattened more like a pillow or saugage. I'll find the link and post it here later. It is an effect that cannot be rationalized by the most zealous flatasser.
From that page:
flat-Earth sunset The exact formula for refraction on a flat Earth allows one to draw the shape of the setting Sun that would be observed in this situation. Here it is, at the right:
The Sun would appear to set on a surface about 1.6° above the astronomical horizon. The drawing shows the Sun's shape at the moment when its lower limb touches this false apparent horizon; the full width of the Sun's disk is shown. Everything between the false horizon and the astronomical horizon would be filled with a gigantic superior mirage of the (flat) Earth's surface.
Qualitatively, this highly flattened sunset image resembles what's seen by an observer inside a duct; see the second image in the simulation showing a wide blank strip. But quantitatively, the negative dip here is an order of magnitude larger than in that case, which is already very unusual. And of course there is no dip at all for the sea horizon in the flat-Earth model, where the sea horizon would coincide with the astronomical horizon.
Although the details of the mirages in this huge blank strip would depend on the density structure of the flat atmosphere, Newton's proof mentioned above guarantees that all sunsets in the flat-Earth model must have exactly this bizarre appearance. In particular, the enormous elevation of the false horizon depends only on the refractive index of air at the observer — a quantity known to many decimal places from laboratory measurements.
The fact that no real sunset on Earth ever has these characteristics can be taken as observational evidence that the Earth is round, not flat.
Copyright © 2003 – 2008 Andrew T. Young
BTW, wife still in hospital, I spent about 4 nights there in a guest room including last night but still have to go to work. She finally got the tube out of her nose pulling bile from her stomach which lowered her pain level she said, by 75%. That was awful. We still have no results from biopsy yet.