If you made an elevator that would go to space (like the one you mentioned in the billion-story building) and built a staircase up (assuming regulated air pressure) about how long would it take to climb to the top? A week or two, if you're a champion stair-climber. Or 12 hours if you're on a motorcycle. A tower to space would be very different from a space elevator. A space elevator would be about 100,000 kilometers tall, while a tower "to space" would only need to be 100 kilometers. As Ethan mentions, it would need to be pressurized, with an airlock every few miles. A stairway to space[1]If there's a bustle in your hedgerow, well, uh, boy, I don't know what to tell you. I guess ask it to leave? would have about half a million steps. World-champion stair-climbers[2]or "towerrunners" like Christian Riedl or Kristin Frey can travel roughly a Mount Everest's height in a day; Riedl set the half-day record last October by climbing 13,145.65 meters in 12 hours. At that pace—taking the other twelve hours to rest, eat, and sleep each day—it would take him a little over a week to reach the top.

Climbing all those stairs would burn calories, which would mean you'd need to carry food. It turns out that the most efficient food you can carry, in terms of calories per pound, is butter—which is why Arctic explorers carry so much of it. Suppose your backpack holds 9 liters. Climbing 10 stairs burns about a calorie, which means climbing all the way up to space will burn about 72,000 calories. If you fill your backpack with butter, it would hold almost enough calories to get you to the top. However, since it would take you weeks to climb all those stairs, you'd also need your normal dietary allowance of 2,000 calories (three sticks of butter) per day. Combining that with the 72,000 calories just from climbing the stairs, and you'd probably need to upgrade to a more serious 16-liter backpack. If you fill that backpack with butter, it will let you carry around 110,000 calories,[3]Coincidentally, about the amount you get from eating a human body. which should be enough to get you to the top if you're really dedicated.

If you didn't want to eat 35 pounds of butter,[4]For whatever weird reason. you could try getting to the top by motorcycle. Based on how quickly this rider ascends 45 stairs, a motorcycle could conceivably make it to the top in a day. Ok, so you got to the top. Getting up to space isn't that hard, after all—the hard part is getting into orbit, and the tower doesn't help you very much with that. So what else could you do? Michael Longuet-Higgins was a research professor at the University of Cambridge and an expert in fluid dynamics, bubbles, and unusual types of waves.Given his apparent research interests, this video would blow his mind.​Or this one, or this gadget, or this. In 1953, Dr. Longuet-Higgins was shown, by a colleague, an "interesting toy" which had recently appeared on the market. This toy, "Slinky," had some unusual properties. The professor immediately set to work analyzing it, and wrote up his results in a paper. Dr. Longuet-Higgins first determined through mathematical modeling that the rate at which the Slinky descends steps should depend only on the properties of the spring itself, and not the size or shape of the stairs.

He and his colleague conducted a series of experiments "on five different flights of stairs, of various dimensions, in Trinity College, Cambridge." Their conclusion: The Slinky descended a constant rate of about 0.8 seconds per step.Except on some wide, flat stairs, where the Slinky "came to rest after three or four steps at most," which gives me a wonderful mental image of two disappointed British professors at the bottom of a staircase.​krewella backpackSadly, this was before the invention of the StairMaster. oztrail backpack reviewFun fact: After a surprise StairMaster management shakeup in 2011, for some reason not a single newspaper ran the headline "StairMaster CEO steps down".backpack danier Dr. Longuet-Higgins determined that the Slinky quickly reached a constant descent rate after first few steps. akona backpack dive bag

This tells us that if you placed a Slinky (similar to his) at top of the stairway to space, and gave it just the right nudge ... ... it would make it back to the bottom in just over five days. Or, to put that in more appetizing units:There are four new shirts in the xkcd store, along with posters and lots of other stuff! RSS Feed - Atom Feed Junior Scientist Power Hour This work is licensed under a Creative Commons Attribution-NonCommercial 2.5 License. This means you're free to copy and share these comics (but not to sell them). The comic refers to the phenomenon of hearing half a conversation from a stranger on a cell phone and, not noticing the cell phone, imagining that that person is talking to you and responding in kind. The chart gives a plot of the frequency that this occurs (for Randall here represented by the Cueball to the left) against the amount of time that passes before the error is discovered. It also implies that Randall's second relationship was in reality just a particularly long instance of this occurrence, suggesting that his 'girlfriend' wasn't even aware of the relationship.

The title text is the continuation of the phone call, which involves a fictional conspiracy involving the then Chairman of the Federal Reserve, Ben Bernanke, and a crossbow. [Caption above the panel:] Sometimes my conversations with strangers go on for a while before I realize that they're talking on their phones. [To the right above a graph Cueball is standing next to a Cueball-like guy with a backpack.] Guy with backpack: Hi! Guy with backpack: What's up? Cueball: Uh, not a lot... Guy with backpack: Shit. Does Bernanke own a crossbow? [To the left and below these two guys is a graph, with the axis labelled. The graph looks parabolic towards the left-hand side, but as x approaches infinity, y approaches zero. A vertical dashed line runs through the graph, slightly to the right of the peak of the graph. To the right of the dashed line there is an arrow pointing to the right that is labelled. The x-axis has a broken scale, and to the right of the break there is a very small increase in the graph that is parenthetically labelled with a small arrow.]

Y-axis: How Often This Happens X-axis: Length of conversation Small arrow: (My Second Relationship)⋅  add a topic (use sparingly)!  Could the Bernanke in question be Ben Bernanke, American economist and currently chairman of the Federal Reserve (i.e. "The Fed")? I assume the crossbows are a reference to something topical, but have no idea what. Might it be a video game of some kind? --MisterSpike (talk) 09:04, 28 June 2013 (UTC)As for the crossbow and "uncontaminated" thing, and tying it all together, there was some big video game set in a post-apocalyptic Washington DC, but I can't for the life of me remember what its name was. --79.222.56.250 12:41, 31 August 2013 (UTC) This was the original Deus Ex, if I remember correctly. This would fit oddly well, actually. There's a huge plague and everything. 199.27.129.161 21:03, 8 January 2016 (UTC) I think the Fallout 3 reference is a bit far-fetched to be anything more than speculation, especially since there's no mention of Ben Bernanke, or any Bernanke, in said game.