Assuming one could create a staircase and walk to the moon, would escape velocity still be a factor in leaving the Earth's gravitational pull? I'm not a physicist but am just curious to know.

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    $\begingroup$ This question appears to be off-topic because it is about Physics and has nothing to do with Astronomy $\endgroup$ – TildalWave Feb 15 '14 at 10:28
  • $\begingroup$ It's also related to Space Exploration (space.stackexchange.com). $\endgroup$ – Gerald Feb 15 '14 at 13:50
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    $\begingroup$ This question appears to be off-topic because it is about engineering and belongs on the SpaceExploration.SE site. $\endgroup$ – astromax Feb 15 '14 at 14:46
  • $\begingroup$ While the staircase idea is silly, the question isn't that bad. Escape Velocity is always there, but building a stair-case from Earth, there's an advantage. The Earth Rotates and there comes a point (about 36,000 km up) where the Rotation equals the escape velocity and you could float off the staircase or literally jump off it and escape the Earth. $\endgroup$ – userLTK Apr 30 '16 at 13:23

A space elevator has been proposed. With currently available technology it would be very expensive to build one, but not necessarily impossible.

Assuming the staircase or elevator being fixed at some point on Earth near the equator, the Earth's gravitational pull is compensated by centrifugal force at a height of about 36,000 km, in the geostationary orbit.

That's the height you would have to climb to, before you could slide "down" to the Moon along an even more expensive construction stepwise adjusting your velocity to that of the Moon. The total trip would be at least about 400,000 km, that's ten times around the Earth.

Your weight would decrease, the higher you climb from ground to the 36,000 km height. Assuming you make 3 km of height each day, it would take you about 34 years to reach geostationary orbit.

Then sliding down with 10 m/s would take at least one more year to reach the Moon. Hence, it's possible with a one-way trip of about 35 years, assumed the technical infrastructure is provided.

But it looks easier to take an appropriate vehicle.

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  • $\begingroup$ It's completely impossible to build an Earth reaching space elevator with current technology, we simply aren't aware of any materials with required tensile strength that could support even its own weight at tether lengths required (GEO is at 35,786 km above mean sea-level, and a counterweight beyond GEO would be required), let alone attach anything on it to make it useful. And there's a few other minor issues with it, such as atmospheric drag, gravity anomalies, vibration, electric current, solar radiation pressure, space debris, tidal forces, and a hundred more. And if it snaps ... $\endgroup$ – TildalWave Feb 15 '14 at 10:45
  • $\begingroup$ @TildalWave Reasearch is ongoing. First step is thought to become a Lunar elevator: sservi.nasa.gov/articles/the-space-elevator-concept . More detailed plans here: science1.nasa.gov/science-news/science-at-nasa/2000/ast07sep_1 . One of the best-suited material (taper ratio below 10) here: mill-creek-systems.com/HighLift/chapter2.html. Lots of issues are discussed here: mill-creek-systems.com/HighLift/faq.html $\endgroup$ – Gerald Feb 15 '14 at 13:33

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