In our case, it’s pretty big: about 150,000–200,000 light years in diameter, and 1000 light years thick on average (Wikipedia ). How much does it weigh?

The Guardian reports today that astronomers have managed to pin down its weight : 3,000 trillion trillion trillion tonnes.

How big a piece of paper is needed to cover the entire Earth?

Size of A0 paper: a x b mm^2 where a = 1189 and b = 841

Size of A-n paper = a * (a/b)^n x b * (a/b)^n mm^2

Diameter of Earth = e ~ 12742000000 mm

To cover the Earth, need:

a * (a/b)^n > e

so

log(e/a) < n log(a/b)
so
n > log(e/a)/log(a/b)

need n > log(12742000000/1189)/log(1189/841) ~ 46.7

So A-47 paper would be sufficient.

I took this photo of the {super, blue, blood, moon}

Super blue blood moon

The mental wanderings of Julian Richardson