[Geezer (OP)]

Looking at the Moon tonight, I realized it might not be too difficult to determine how far away it is.

Who was the first person to establish a close estimate?

[Don_1]

Someone with a very long tape measure. Oooo! That smarts!

[peppercorn]

Have you been at the moon-shine again Don?  []

[Don_1]

Could it have been a luna miles

[Don_1]

It was some old geezer (perhaps you're related to him or at least know him ) by the name of Harry Starkers (or summat to that effect)

 Aristarchus 310 BC or thereabouts.

[Geezer (OP)]

How did Harry work it out? Did some time traveller bring him a "frikin' laser" so he could bounce a light beam off the Moon?

[Don_1]

He was klevur old geezer, did it like this.

[Bill S]

If you look at the thread about dangling a string over a black hole, you will find you can get up there with a ladder, and lose weight at the same time.  Wonderful thing science  []

[syhprum]

Sir Isaac Newton had serious doubts about his theory of universal gravitation because the accepted value of the distance of the Moon was incorrect.