r/whowouldwin • u/ThePriestofVaranasi • Jul 09 '25

Challenge Every human on Earth vanishes, except for one random person in the US. A button is placed on the summit of Mount Everest that can be pressed to undo this change. Can humanity be restored?

Every human on Earth vanishes without a trace, except for one random survivor: Ethan from the United States. Moments after the disappearance, a mysterious device materializes before him, displaying a message:
"Humanity can be restored. To activate revival, you must press the button housed at the highest point on Earth—the summit of Mount Everest."

Ethan essentially has as much of a prep time as he wants to gather all the essentials like food, water, weapons, vehicles and everything else that has been suddenly abandoned. He can raid supermarkets, libraries, military depots, and pharmacies for supplies. Ethan can still die of old age so this prep time isn't unlimited.

Now, Ethan faces an impossible gauntlet:
He must travel to Nepal and ascend to the summit of Mount Everest without dying.

Can Ethan survive long enough to reach the button and restore humanity?

1.5k Upvotes

95% Upvoted

839 comments sorted by

View all comments

Show parent comments

21

u/TyrconnellFL Jul 09 '25

How long does GPS stay functional without human oversight?

37

u/rexus_mundi Jul 09 '25 edited Jul 09 '25

About 7 years at most, fuel is required to maintain their orbits along with updates from the ground. They will become less effective over time with orbital drift, and degradation of parts

3

u/guyblade ​ Jul 10 '25 edited Jul 10 '25

Shorter than that. The satellites need their ephemeris information updated constantly by the ground, usually every few weeks. I'm not sure if it remains true with the Block III GPS satellites, but I heard the Block II GPS satellites described as "big tape recorders" once: you basically uploaded the timed list of what it was to broadcast and when and it simply dumped that back out. That's not an unreasonable model when most of the complex work--high precision prediction of their orbits--is being done on the ground anyway.

13

u/FreeBricks4Nazis Jul 09 '25

As I understand it (not well) the GPS constellation of satellites is receiving regular calibration from the United States Air Force.  I have no idea how crucial this calibration is.  The accuracy of the system is probably going to degrade relatively quickly, but I don't know if that means your fix is going to be off by a couple of feet or a couple of miles. 

11

u/ghotier Jul 09 '25

Calibration is important enough that GPS didn't work well enough for commercial use until General Relativity was figured into the calculations to account for the time dilation experienced due to Earth's gravity (which is VERY small)

7

u/bigloser42 Jul 09 '25

It was general relativity, it was unencrypting the military channels that allowed extreme accuracy. But That only fixed the issue that didn’t let surveyors use it. It was good enough for almost anything else before that. It just took a while for it to get cheap enough to widespread adoption.

1

u/Normal_Ad_2337 Jul 10 '25

Relatively large though.

1

u/Leninlover431 Jul 10 '25

*special relativity

1

u/ghotier Jul 10 '25

No, it's actually general relativity.

1

u/Leninlover431 Jul 10 '25

I'm positive special relativity is a much larger factor than general reality in the context of sats

1

u/ghotier Jul 10 '25

Maybe, the math is certainly doable if you want to, but they solved the General Relativity problem last. Before they solved that problem, GPS was not effective enough for its current use. And my point was to compare the small, necessary correction of GR to the calibration corrections that need to be done. A larger correction is less persuasive with respect to the size of the calibration.

2

u/brickmaster32000 Jul 09 '25

GPS can only give you your latitude and longitude. It doesn't give you a map. To do all the tracking people want to do you need all the infrastructure that isn't going to stay up that long.

7

u/TheShadowKick Jul 09 '25

There are GPS devices where the maps are already loaded onto the device. You can power them with batteries so you don't really need infrastructure to keep them going (at least in the short term).

3

u/brickmaster32000 Jul 09 '25

You certainly need infrastructure to find them. You guys seem to think that if something exists it will magically fly its way into Ethan's pockets.

6

u/TheShadowKick Jul 09 '25

I mean, I bought a GPS device with maps loaded onto it at Best Buy. They aren't hard to find.

-7

u/brickmaster32000 Jul 09 '25

Very much doubt the maps it was preloaded are anywhere near the level of details needed.

-8

u/captain-_-clutch Jul 09 '25

GPS probably forever. Weather I'm not sure.

8

u/Adventurous_Web_2181 Jul 09 '25

Not forever. They are designed to operate for 10-12 years before wear and tear on electronic components, including solar panels, accumulates. There will also be a degradation of their orbit when maneuvering fuel runs out. Should be perfectly usable for 5 years with decreasing accuracy over time.

1

u/Hannizio Jul 09 '25 edited Jul 10 '25

While the satellites themselves wont fail, I'm not sure about other things that are needed to keep the gps grid running. Online servers like google maps could be down within the week, and I'm not sure that your normal smartphone gps system (or the gds satellites) could handle a situation like this

2

u/Adventurous_Web_2181 Jul 09 '25

He would need to rely on handheld GPS units, like Garmin. Not sure if they have coverage for Everest. And, he can always fall back to paper maps.

1

u/Hannizio Jul 10 '25

True, but paper maps could become problematic once they stop being in english

0

u/captain-_-clutch Jul 09 '25

Not literally forever. 10+ years is plenty of time for our hero

0

u/TheShadowKick Jul 09 '25

GPS will last long enough that it won't be the point of failure.