Thread

1. gorgoiler · 1790191708 · focus · HN ↗

   Presumably when World War 3 kicks off the very first thing each adversary will do is knock out their opponents satellites? These are like flying lightbulbs that shine down usefulness from above, so step one is to cut the lights.

   Presumably-squared there is some kind of military backup to survive once the lights (GPS) go dark? Whatever that technology is, why hasn’t it proliferated into civilian life so that we all benefit from a resilient, non-GPS backup?

   Perhaps the answer is that every tank has a 10lb inertial navigation gyro or some other thingy in it as a backup, and the platoon around it uses the tank as a moving trig point? In that case I can see it being infeasible to deploy that for civilians.

   Perhaps-squared it’s just economics — GPS is cool and cheap now, so why burn profit margin on developing an alternative?

   1. nradov · 1790195261 · focus · HN ↗

      Right, in future conflicts between major countries the satellites will be first casualties. The US military is aware of this and still trains personnel on analog navigation techniques. Inertial navigation works well for some missions and research is underway on alternative technologies. Civil airliners can still navigate without GPS, although this may reduce safety and increase workload.

      <a href="https:&#x2F;&#x2F;interestingengineering.com&#x2F;military&#x2F;us-military-nails-gps-free-navigation" rel="nofollow">https:&#x2F;&#x2F;interestingengineering.com&#x2F;military&#x2F;us-military-nail...

      We&#x27;re also going to need a prompt launch capability to replace attrition losses. There should be warehouses full of spare navigation, reconnaissance, and communications satellites ready to mount on a reusable booster and launch within hours. Concerns have been raised over a &quot;Kessler syndrome&quot; due to orbital debris but in lower orbits with significant atmospheric drag this won&#x27;t be a serious problem.

      1. pchristensen · 1790199108 · focus · HN ↗

         Reminds me of in the Avengers - SHIELD couldn&#x27;t navigate the helicarrier, and Nick Fury said &quot;Is the sun setting? Then put it on our left!&quot;

         1. FlowingRiver · 1790212449 · focus · HN ↗

            This is the easiest trick technique for figuring out vaguely north&#x2F;south direction.

            Take an analog watch. Say it is 9am, point the 12pm&#x2F;midday point of the watch at the horizon directly below the sun, the half way distance between the hour hand and 12pm is the fairly close direction of the pole. So in that case, the 10:30am point would be the pole.

            In the northern hemisphere it points South, in Southern hemisphere it points North.

            EDIT : The Wikihow article shows it better.

            <a href="https:&#x2F;&#x2F;www.wikihow.com&#x2F;Use-an-Analog-Watch-as-a-Compass" rel="nofollow">https:&#x2F;&#x2F;www.wikihow.com&#x2F;Use-an-Analog-Watch-as-a-Compass

            It is an old Army&#x2F;SAS trick for keeping baring without a compass.

            1. jasomill · 1790224787 · focus · HN ↗

               This reminds me of this scene from Rosencrantz and Guildenstern Are Dead when they&#x27;re trying to figure out whether Hamlet knows a hawk from a handsaw by the direction of the wind.

               <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=pf0erXl4pwQ" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=pf0erXl4pwQ

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