1 00:00:00,250 --> 00:00:05,100 We’ve all been there: you’re in your 2006 Honda Civic at an altitude of 60,000 feet, 2 00:00:05,100 --> 00:00:08,440 cruising along at 1,200 miles per hour on your way home from work. 3 00:00:08,440 --> 00:00:13,670 But all of a sudden, your GPS shuts down, and now you have no idea how to get home. 4 00:00:13,670 --> 00:00:16,890 At first this sounds like it’s probably a technical limit, right? 5 00:00:16,890 --> 00:00:20,500 The chimpanzees that they put in the satellites to watch your car with high-powered telescopes 6 00:00:20,500 --> 00:00:24,130 just can’t keep up past a certain speed or at a certain altitude. 7 00:00:24,130 --> 00:00:29,019 But that’s not quite right—your GPS would theoretically work just fine at 1,200 miles 8 00:00:29,019 --> 00:00:31,060 per hour or at 60,000 feet. 9 00:00:31,060 --> 00:00:36,960 The actual answer is much weirder—your GPS manufacturer set those seemingly impossible 10 00:00:36,960 --> 00:00:42,070 limits on purpose because they wanted to stop you from starting a thermonuclear war… technically. 11 00:00:42,070 --> 00:00:43,829 Let me explain. 12 00:00:43,829 --> 00:00:47,899 The Global Positioning System, as a service, isn’t just some free utility that was handed 13 00:00:47,899 --> 00:00:52,520 down to us by God; it was actually created by the only force more powerful than God: 14 00:00:52,520 --> 00:00:53,960 the US Department of Defense. 15 00:00:53,960 --> 00:00:58,940 You see, in the early 1970s, the US was having a little trouble keeping track of all of its 16 00:00:58,940 --> 00:01:02,670 nuclear submarines, which, y’know, are not the kind of thing you want to lose track of. 17 00:01:02,670 --> 00:01:06,940 At the time, these submarines were being tracked with a satellite navigation system called 18 00:01:06,940 --> 00:01:11,080 “Transit,” which worked a whole lot like GPS—a submarine could calculate its approximate 19 00:01:11,080 --> 00:01:14,970 location on Earth by measuring its distance from two or more Transit satellites. 20 00:01:14,970 --> 00:01:19,710 But this system had a bit of a problem: there just weren’t enough satellites to go around. 21 00:01:19,710 --> 00:01:24,250 At any given time, the system would use five satellites to cover the entire Earth, and 22 00:01:24,250 --> 00:01:28,380 that meant that most of the time, a submarine would only have line-of-sight to one of them. 23 00:01:28,380 --> 00:01:32,229 It was still technically possible to calculate a rough location with the measurements from 24 00:01:32,229 --> 00:01:36,170 one satellite, but that involved a whole bunch of convoluted physics and math stuff that 25 00:01:36,170 --> 00:01:39,290 I don’t really have time to explain, so I’m just gonna put up a screenshot of a 26 00:01:39,290 --> 00:01:42,950 Wikipedia article here for exactly one second and you can go ahead and pause the video if 27 00:01:42,950 --> 00:01:43,950 you’re into that kinda stuff. 28 00:01:43,950 --> 00:01:46,850 Now for all the people who didn’t pause the video because they’re cool and hate 29 00:01:46,850 --> 00:01:51,630 science, the main takeaway was that this system technically worked but… not very well. 30 00:01:51,630 --> 00:01:55,420 The US military needed something more reliable for their submarines, so they rolled out the 31 00:01:55,420 --> 00:01:57,759 system we use today: Navstar GPS. 32 00:01:57,759 --> 00:02:02,229 There were more satellites, with more accurate equipment, and a modern GPS receiver almost 33 00:02:02,229 --> 00:02:06,350 always has line-of-sight to at least four satellites on even the most remote locations 34 00:02:06,350 --> 00:02:07,350 on Earth. 35 00:02:07,350 --> 00:02:08,740 Yes, even in Ohio. 36 00:02:08,740 --> 00:02:12,840 But here’s the thing: when the Department of Defense spent billions of dollars developing 37 00:02:12,840 --> 00:02:16,870 GPS, it wasn’t meant to be a public worldwide utility that made everyone’s lives easier 38 00:02:16,870 --> 00:02:17,870 and more convenient. 39 00:02:17,870 --> 00:02:20,980 In fact, there’s a whole section in the constitution prohibiting that. 40 00:02:20,980 --> 00:02:24,970 For the first year that the system was in use, it was completely classified—not only 41 00:02:24,970 --> 00:02:28,630 did the public not have access to it, they didn’t even know it existed. 42 00:02:28,630 --> 00:02:33,010 And that’s because, at least at the time, the big technological advancement of “knowing 43 00:02:33,010 --> 00:02:37,010 where stuff is” was really dangerous; knowing where your submarines are, knowing where your 44 00:02:37,010 --> 00:02:40,340 missiles are, and knowing where the people you want to blow up are are all important 45 00:02:40,340 --> 00:02:42,569 ingredients in… blowing people up. 46 00:02:42,569 --> 00:02:46,811 No other country had access to this kind of global positioning technology, and the US 47 00:02:46,811 --> 00:02:48,800 was not eager to give it up. 48 00:02:48,800 --> 00:02:55,379 But, fast forward to September of 1983—this flight, Korean Air 007, accidentally drifted 49 00:02:55,379 --> 00:03:00,870 into Soviet airspace on its way from Anchorage to Seoul, got shot down, and everyone on board 50 00:03:00,870 --> 00:03:01,870 was killed. 51 00:03:01,870 --> 00:03:06,030 Now, it was pretty obvious that this incident could have been avoided entirely if the US 52 00:03:06,030 --> 00:03:10,180 government had made GPS accessible to civilians and private airlines. 53 00:03:10,180 --> 00:03:14,470 The president at the time, Ronald Reagan, was probably a little conflicted—on one 54 00:03:14,470 --> 00:03:18,150 hand, killing innocent people was his favorite pastime, but on the other hand, he was almost 55 00:03:18,150 --> 00:03:19,569 up for reelection. 56 00:03:19,569 --> 00:03:24,050 Making GPS public in 1983 wouldn’t be as big of a national security issue as it was 57 00:03:24,050 --> 00:03:28,150 when it was first rolled out; the Soviet Union had already launched their own GPS system, 58 00:03:28,150 --> 00:03:32,220 GLONASS, the year before, so it didn’t really matter if they got their hands on Navstar. 59 00:03:32,220 --> 00:03:37,060 So, two weeks after the Korean Air incident, Reagan opened GPS to the public, but this 60 00:03:37,060 --> 00:03:40,040 came with a couple of security caveats. 61 00:03:40,040 --> 00:03:43,620 The first was that the signal would be partially scrambled, making it only accurate within 62 00:03:43,620 --> 00:03:46,269 about 300 feet or 100 meters. 63 00:03:46,269 --> 00:03:50,140 That way, if someone was going to nuke the White House, they might miss by a little bit. 64 00:03:50,140 --> 00:03:54,380 This restriction was later overturned by Bill Clinton in 2000, because he wanted young people 65 00:03:54,380 --> 00:03:55,380 to think he was cool. 66 00:03:55,380 --> 00:03:59,330 Now, the other main caveat was put in place by the Department of Commerce, and it was 67 00:03:59,330 --> 00:04:00,330 this. 68 00:04:00,330 --> 00:04:04,939 Basically, any GPS receiver that was exportable—meaning that it could be sold outside the US—would 69 00:04:04,939 --> 00:04:08,319 need to put height and speed limits in place that would shut it down if it were attached 70 00:04:08,319 --> 00:04:09,910 to a ballistic missile. 71 00:04:09,910 --> 00:04:14,580 These limits have been hard-coded into pretty much every GPS ever since; some shut down 72 00:04:14,580 --> 00:04:20,190 at 1,200 miles or 2,000 kilometer per hour or above 60,000 feet or 18,000 meters, and 73 00:04:20,190 --> 00:04:22,300 some shut down only when both limits are reached… 74 00:04:22,300 --> 00:04:25,840 even though that’s technically not how the law is written, but whatever. 75 00:04:25,840 --> 00:04:28,810 The big question is… do these limits actually affect anyone? 76 00:04:28,810 --> 00:04:32,380 And the short answer is not really—that’s kind of why they’re still in place; they 77 00:04:32,380 --> 00:04:35,470 don’t bother anyone, and there isn’t really any point in getting rid of them. 78 00:04:35,470 --> 00:04:39,150 But the long answer is yes, they affect a very specific group of nerds who like to send 79 00:04:39,150 --> 00:04:42,870 balloons to high altitude so that they can learn what cold garlic bread tastes like. 80 00:04:42,870 --> 00:04:46,060 But until those nerds work up the confidence to write a letter to the Department of Commerce, 81 00:04:46,060 --> 00:04:48,919 you’ll have to keep your car under 1,200 miles per hour. 82 00:04:48,919 --> 00:04:53,250 So, okay, your phone can’t track your location at 60,000 feet. 83 00:04:53,250 --> 00:04:54,650 But you know what it can do? 84 00:04:54,650 --> 00:04:59,280 It can make you smarter—that is, with the help of our sponsor, Brilliant. 85 00:04:59,280 --> 00:05:03,490 Brilliant is an amazing way of keeping your brain engaged every single day without any 86 00:05:03,490 --> 00:05:04,490 hassle. 87 00:05:04,490 --> 00:05:08,460 They have fun, intuitive, interactive lessons on almost any STEM subject you can think of. 88 00:05:08,460 --> 00:05:11,180 Want to know more about the satellites we talked about today? 89 00:05:11,180 --> 00:05:13,139 Try their course on gravitational physics. 90 00:05:13,139 --> 00:05:14,510 Wondering what the deal is with your fingerprints? 91 00:05:14,510 --> 00:05:17,500 You’ll learn about that in their course on computational biology. 92 00:05:17,500 --> 00:05:19,250 Your girlfriend keeps cheating on you? 93 00:05:19,250 --> 00:05:22,870 Brilliant can teach you the key to truth-seeking in their course on logic with fun puzzles 94 00:05:22,870 --> 00:05:26,360 like this one, where you have to sit robots on an airplane in a particular order to stop 95 00:05:26,360 --> 00:05:27,740 them from killing each other! 96 00:05:27,740 --> 00:05:30,100 With Brilliant, you can be a lifelong learner. 97 00:05:30,100 --> 00:05:34,120 You’ll be absorbing complex topics quickly and easily, squeezing in daily lessons during 98 00:05:34,120 --> 00:05:35,830 commercials or on your walk to work. 99 00:05:35,830 --> 00:05:39,660 It’s a great way to kill some of that spare time, and turn it into something productive. 100 00:05:39,660 --> 00:05:44,300 Best of all, to get started for free, visit brilliant.org/hai or click the button on-screen, 101 00:05:44,300 --> 00:05:48,819 and the first 200 of you will get 20% off Brilliant's annual premium subscription.