"Yeah, once you get the theory and you've worked with it for awhile, it's not that much harder than remembering how to calculate a tip in a restaurant," Avram said. "You just learn it."
The news that the computers had been tampered with wasn't great, though. "Okay, hmm. Well, even without having the time zone as a clue, we can give it a try. Latitude is super easy to figure out—all we need is a clear night. Find the angle of Polaris above the horizon, and there's our latitude. If it's 45° above the horizon then we're at 45° north. Can't fuck that up. If we could find a protractor somewhere that'd be useful, but of course you can find the angle without one using trig. For longitude we'd need to make a sundial and time it to find local noon, and then...I guess we just take a guess at the time zone. We can rule out some of them based on geography, right? Like, we're clearly not on the prairies, just based on looking out the window. But the Sun moves at 15° per hour, so we can use local noon and our best guess at GMT to figure out longitude. I think we can skip the equation of time since we're not going to get a highly accurate result anyway," he added, mostly to himself. "But yeah, if that doesn't work...we'd be mathematically fucked. Even the lunar distance method needs a GMT reference."