
The illusion of the local dome
Measuring the cosmic gap
Our actual backyard neighbors
The local bubble and beyond
YOUR GOAL
Master of Mapping our local cosmic neighborhood
007skaty The Celestial Dome Illusion
The stars look stuck to a local dome (local dome!) / But depth is a trick that our eyes don't own (eyes don't own!)

007skaty Egyptian beliefs about the goddess Nut and Hebrew texts describe the firmament as a solid metal or stone

007skaty Concentric crystalline spheres carry the Sun, Moon, and stars around a central Earth.
Celestial dome: The ancient Greeks calculated that the sphere of stars was only about 20,000 times larger than Earth's radius.
Which Greek astronomer formalized the geocentric model of the universe in the 2nd century CE?
If you look up at the night sky without a telescope, how does the distance of stars appear to change?
Why did ancient Greek astronomers like Aristotle argue that the Earth did not move?
What is the main reason the night sky looks like a flat, two-dimensional dome to our eyes?


