Japanese footprint from underneath

If the Earth was a glass sphere…
and you were standing on its surface…
opposite Japan…
and you were looking past your feet at the footprint that the country of Japan made…
and your eyes were exactly six feet from the ground when your head was bent forward to see said Japan…
and there was a ruler at your feet…
and you were alternately focusing on the ruler and then Japan…
How big would Japan appear to be?

Feel free to exchange feet for meters, cubits, rods, or six pounds tuppence, I don’t care. And lets round off the diameter of the Earth for simplicitys sake, shall we?

I dont think you’d be able to see it. I’m better it would be too far away to make out. And it may be too fuzzy to measure. But I’m just guessing.

About 9 inches long.

Japan is about 1000 miles long.
The Earth is about 8000 miles in diameter.

That’s a ratio of 1:8.

If you’re looking at something 6 feet away that appears about the same size as Japan does when it’s 8000 miles away, the size of that thing is 6 feet / 8.

Or, just about 9 inches.

Phinneus J Pochacco , You’re a genius! Short and to the point. I LIKE IT!

Just slightly larger. Very, very, very slightly. If you want to stand on land (the beach of Brazil), then the nearest Japanese landmass will be about 10-20 miles off of the antipodal. Once you start moving away from the antipodal, you move closer to the object you’re looking at.


Nope, we’re on a glass bottom boat 20 miles off the coast of Brazil.

If the earth were a sphere of glass, wouldn’t the curved glass surface act as a lens, distorting the size (from the viewer’s point of view) of the footprint of Japan? If you ask me, we need an optics expert in here.

I think “glass” might have been used as a convenient metaphor for “transparent medium.”

I think the curvature of the glass would be negligible, no?

You’d be quite tall.

Maybe he’s standing on a box. And for arguments sake, let’s say the glass is infinitely thin. And hollow.

And that the earth is full of bees. Or dogs. Or dogs that shoot bees out of their mouths…

All this seems like a lot of trouble to go through in order to look up Japanese schoolgirl’s skirts… :wink:

I agree. However, refraction at the (almost) flat surface does change the apparent distance. You’ve probably seen the effect when looking down into a swimming pool. Assuming n=1.5 for the glass, Japan would appear to be 8000/1.5=5400 miles away. So 12 inches would be my answer.

Just a simple question. :rolleyes: Not a problem in rocket science!

Do nothimg simply when a way can be found to make it complex and wonderful.

And how big would be the four elephants and the turtle?

You know, the deepest body of water on earth would look really cool if the bottom was all glass. What is it, again? Did anybody go there? How many times? When?

Man has visited the deepest part of the worlds oceans, Challenger Deep in the Mariana’s Trench, just once. In 1960. For 20 minutes.