Spartan07

There was a U2 driver here that used to post all sorts of amazing photos that would show the curvature of the earth. Maybe he's around and can chime in on this, I know we had this discussion before on Photos... Speaking of which, Are we ever going to get that forum back? Pleeeease?

N7225G

I think ur talkin about jungle, hes still lurkin around, i bet he knows

limelight

Realize that a wide-angle lense can make photos look as if there's curvature in the earth. I've been up to 37,000 feet over the Pacific numerous times and have never seen this. I doubt another 30 or so thousand feet would make much difference. The earth is around 21,000 miles around. and the U2 is approx 10 miles up. Sounds kinda far-fetched to me.

Spartan07

Nah, Jungle is a cargo bubba. An extremely well informed one though so he might actually know. I think the guys name was literally U2Driver or something. And again, I'm not pretending to know the science behind it but he definately did and had some amazing pictures to boot. I wish he were around to explain what it was we were seeing again.

jungle

Actually the curve of the Earth's radius can be seen from the ground given good visibility as per the quoted examples from Wiki. To get the best effect from the air, 50-60,000 feet is considered the minimum, although this depends on visibility and it can be seen from lower altitudes under the right conditions.

[edit] Distance to the horizon
Examples:

Standing on the ground with h = 1.70 m (eye-level height), the horizon is at a distance of 4.7 km.
Standing on a hill or tower of 100 m height, the horizon is at a distance of 36 km.
To compute to what distance the tip of a tower, the mast of a ship or a hill is above the horizon, add the horizon distance for that height. For example, standing on the ground with h = 1.70 m, one can see, weather permitting, the tip of a tower of 100 m height at a distance of 4.7+36 ≈ 41 km.

Here is a good site for viewing the effect from higher altitude:

http://eol.jsc.nasa.gov/Coll/weekly.htm

Spartan07

Outstanding, Thank's for clearing that up Jungle. Now if only the photos forum would open back up...

leardriver

Had A LEAR 31A up to FL 510 one day. Thought I could see the curve but it just turned out to be the curve of the learjet winshield! Sky gets dark though. And most of the noise goes away.

joel payne

A termination notice ?? LOL

Roll Inverted and Pull

In 1963 my wingman and I were to go after a U2, big exercise... We were in full pressure suits, flying Chance Vought F8E`s. Mach 1.8 at 35,000, pitched up 30 degrees in a zoom climb. We gave out of energy at 61,000, no where near the U2. If you think he flies at 60,000, you are about 40,000 off.The curvature of the earth was plainly visable, as was a really dark blue sky.

Spartan07

Oh by the way guys, got the 52 up just above flight level 040 (That's 4,000 ft for you low level fliers) and I couldn't see the curvature. The only reasonable assumption is that it doesn't exist and you're all full of chit.