[Prof. Templeton]

John had been walking through the great expanse for some time now and he was starting to get weary. Ever since this vast portion of the red Martian surface had been smoothed over, so that it was perfectly spherical in this area, nothing had been built except for the Monolith. That was where he was headed. The monolith stood an impressive 1000 meters tall with a brilliant silver band that was exactly halfway up the exterior surface. As John looked toward the horizon he could just make out the band level with it, the rest of the monolith jutting up into the sky. He judged his current walking pace to be 6.2 kilometers per hour. From his time in the System Corps, he knew he could maintain this pace until he collapsed. And collapse he would, his 1.8 meters tall frame laying in a heap upon the surface, his goal still in sight over the horizon. But only if he didn’t reach the Monolith before his oxygen was gone. John checked the gauge on his tanks. Exactly 10 hours worth was left. He hoped he would make it. Once he reached his destination he would take the lift up to the entrance portal. The lift was fully automated, (the Monolith had been abandoned for centuries) it would open up for 10 seconds at the base of the structure, take 1 minute to complete the ascent, be open for 10 seconds at the entrance, then descend back to the base taking another minute. John didn't worry if the lift had malfunctioned nor if the mechanics inside the Monolith itself ceased to work. He knew who built them. Thinking ahead to a 1 minute lift ride did strike him as optimistic, however. He had a long way to go. And alot depended on him getting there.

Does John definitely make it inside the Monolith before his air runs out?

John's eyes are on the top of his head.

The diameter of Mars is 6,794 kilometers.

John's pace is 6.2 kph and never changes even as his oxygen starts to run out. As soon as it's gone he keels over.

[Guest]

He can make it to the monolith with 2 minutes, 9.3 seconds to spare, but if he reaches the door precisely when it is closing, he will run out of air too soon. His odds are high, but not guaranteed.

Edited June 5, 2009 by pieater3141

[Guest]

He has a chance, but it's iffy.

through my calculations, I get a distance of 61.79km to the base of the monolith. at a rate of 6.2kph, he should get there at 9.966129 hours. this calculates out to 9hours 57minutes and 58 seconds, leaving 2 minutes and 2 seconds. if the lift went up exactly at the moment he reached the base, he'd take 3minutes and 20 seconds to make it into the monolith. I'd say he's got a 60% chance of making it (what if he held his breath for 10 seconds every hour??)

[Guest]

Does John definitely make it inside the Monolith before his air runs out?

my calculations show that he can wait at most 59.344 seconds for the doors to OPEN at the bottom. (time of arrival + the 70 seconds from the time the doors open til it reaches the top). This means that he must arrive between the time just after the doors close on the top to the time that the doors close on the bottom. If he arrives between the time the doors close on the bottom to the time just after the doors close on the top, his goose is cooked.

So no, he does not definitely make it inside the monolith.

Of course, we could definitely answer the question if we knew the position of the elevator at time zero

Edited June 5, 2009 by tpaxatb

[Glycereine]

He has a chance, but it's iffy.

through my calculations, I get a distance of 61.79km to the base of the monolith. at a rate of 6.2kph, he should get there at 9.966129 hours. this calculates out to 9hours 57minutes and 58 seconds, leaving 2 minutes and 2 seconds. if the lift went up exactly at the moment he reached the base, he'd take 3minutes and 20 seconds to make it into the monolith. I'd say he's got a 60% chance of making it (what if he held his breath for 10 seconds every hour??)

Skip breathing doesn't reduce the rate of oxygen consumption, in fact it most often increases it. The build up of carbon dioxide furthers the urge to breath and you breath more deeply and quickly than necessary when you cease holding your breath. There are some exceptions if the breath hold isn't too long but figuring he's working fairly hard any breath hold at all would probably not help.

. For the record I ended up with 2 minutes 8 seconds but I'm sure it's a rounding issue.

Chance of survival being then slightly over 60%.

[Guest]

No. He is short by 10.65600479 seconds.

[Prof. Templeton]

And thank you for confirming my own calculations. His success is not definite as everyone has shown.