The soldiers march 25 miles [closed]

An infantry platoon marches across the barren landscape. Says the captain, "We will march 25 miles today, soldiers!" And indeed, by nightfall, they have marched 25 miles. But when they prepare to set up their sleeping quarters, they find that they are in exactly the same place they started! They marched in an exactly straight line, and no other transportation was used.

Hint:

It is necessary for the soldiers to wear special clothing to survive here, and there is a specific place I am talking about

Another hint: (Don't read unless necessary)

The distance of 25mi matters

closed as too broad by ffao, QuantumTwinkie, Glorfindel, Beastly Gerbil, NL628Apr 27 '18 at 22:40

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• You're maybe giving hints a little too fast. Don't hesitate to wait a few hours (some will say a day) before giving an hint. – Saeïdryl Apr 27 '18 at 13:40
• Maybe the soldiers should be following a tank whose treads both moved at exactly the same speed (and thus traveled the same distance) without slippage. If the tank were going around the pole of a planet that was much more than 25 miles in circumference, the distance traveled by the treads would differ by almost as much as if the tank made a much smaller circle. – supercat Apr 27 '18 at 20:17

We are in the future : the soldiers are marching on a 8 miles diameter asteroid and they need special clothing to be able to breathe

(EDIT) and to be more precise

we're on Ijiraq one of Saturn's moons (approx 8 miles diameter)

Or

Deimos one of Mars' moon works too

• Close, but I'm thinking of a specific place – Redwolf Programs Apr 27 '18 at 13:36
• Please hide your answers with a spoiler tag (">!") – Saeïdryl Apr 27 '18 at 13:39
• sry i forgot the spoiler – Kant1 Apr 27 '18 at 13:40
• Third idea is correct! – Redwolf Programs Apr 27 '18 at 13:59
• I'm not sure such a place would have sufficient gravity to be able to "march". – Alexis Olson Apr 27 '18 at 22:03

I think they are

Either in the North or the South pole, and they made a big circle. They need special clothing because it's quite cold

• What about the straight line part? – Redwolf Programs Apr 27 '18 at 13:35
• in a straight line – TinyTRex72 Apr 27 '18 at 13:35
• @Saeïdryl I think the point is that there is a point, somewhere just south of the North Pole (probably only a few miles), where walking due east (c.f. west) for 25 miles will return you to your starting point. The same will be true of the south pole. – MD-Tech Apr 27 '18 at 14:14
• @user2357112 True, so the accepted answer is just as "curved" as this solution—it's just that the soldiers' bodies are oriented differently with respect to the curve in each scenario (walking around a sphere curves down, while this solution curves the same amount but just left or right) – maxathousand Apr 27 '18 at 18:00
• @maxathousand: Both answers are curved from the perspective of the ambient space, but the accepted answer is straight in the (generalized) sense of being a geodesic of the space formed by the surface of the celestial body the soldiers are marching on, which this answer isn't. – user2357112 Apr 27 '18 at 18:11

Are they

• You should spoiler your answer by starting the line with >! – Laurel Apr 27 '18 at 19:04
• ohhh okay ... will do – MrClan May 1 '18 at 4:03
• That's one big piece of exercise equipment – Redwolf Programs May 9 '18 at 12:17

My first thought was

they are future soldiers marching along the inside of a ringworld (or halo, or dyson sphere)

May be this:

They walked 25 miles from their camp A in a straight line and arrived in a camp B. The camp B is built exactly the same as camp A. The landscape is barren and so as a result, it is very difficult to tell that the location is different; only the camp can provide clues but here they are exactly the same.

• Welcome to Puzzling! Unfortunately, since the question states that they ended "exactly where they started" (and not that it only looked like the place they started in), this does not seem like a valid answer to me. – ffao Apr 27 '18 at 20:06