1 00:00:00,000 --> 00:00:08,040 I'm in Oslo, Norway for the World Year of Physics, but now I'm studying some of the 2 00:00:08,040 --> 00:00:23,040 history and culture of this great country. 3 00:00:23,040 --> 00:00:41,040 Wow, I'd better get to the Viking Ship Museum for my video conference. 4 00:00:41,040 --> 00:00:46,540 I've got to hand it to the Vikings. 5 00:00:46,540 --> 00:00:50,040 How they found their way across the Atlantic Ocean without maps is amazing. 6 00:00:50,040 --> 00:00:55,040 Well, they didn't have maps like ours, but they were pretty sophisticated navigators. 7 00:00:55,040 --> 00:00:59,040 Hi, Dr. D. I was beginning to wonder if you were going to find the museum. 8 00:00:59,040 --> 00:01:02,040 Well, it's easy to get distracted when you're doing research. 9 00:01:02,040 --> 00:01:06,040 And soon I'll be going to Andanus about the Arctic Circle to see the Northern Lights. 10 00:01:06,040 --> 00:01:09,040 Dr. D., isn't the Alomar LiDAR Observatory in Andanus? 11 00:01:09,040 --> 00:01:12,040 Yes, but how do you know about the Observatory in Andanus? 12 00:01:12,040 --> 00:01:15,040 Ulla and Nina, some of our fellow geocachers, live there. 13 00:01:15,040 --> 00:01:18,040 And they also happen to be members of the NASA Sci-Files Kids Club. 14 00:01:18,040 --> 00:01:22,040 That's cool. If you send me their coordinates, I can meet them. 15 00:01:22,040 --> 00:01:27,040 Speaking of coordinates, as I mentioned in my email, I have some questions about the history of navigation. 16 00:01:27,040 --> 00:01:28,040 Where do you want to start? 17 00:01:28,040 --> 00:01:33,040 Didn't the Vikings discover America about 1000 A.D., long before Columbus? 18 00:01:33,040 --> 00:01:37,040 That's right. The Vikings were excellent navigators and shipbuilders. 19 00:01:37,040 --> 00:01:40,040 This Viking ship, made of oak, is called the Oseberg. 20 00:01:40,040 --> 00:01:46,040 It is 22 meters long and was likely the burial ship of a Viking queen. 21 00:01:46,040 --> 00:01:50,040 The Gokstad was probably built around 890 A.D. 22 00:01:50,040 --> 00:01:54,040 In addition to sails, it also had 16 pairs of oars. 23 00:01:54,040 --> 00:02:03,040 In 1893, a replica of the Gokstad sailed from Norway to Canada in 28 days, without the aid of a compass. 24 00:02:03,040 --> 00:02:05,040 Wow, that's amazing! 25 00:02:05,040 --> 00:02:07,040 Shh! 26 00:02:07,040 --> 00:02:09,040 How do they navigate without a compass? 27 00:02:09,040 --> 00:02:11,040 The Vikings probably used stars to navigate. 28 00:02:11,040 --> 00:02:16,040 A star named Polaris, which is located above the Earth's north pole, can be used to find north. 29 00:02:16,040 --> 00:02:19,040 I know. Polaris is sometimes called the North Star. 30 00:02:19,040 --> 00:02:23,040 It's always in the same place in the sky, and you use the Big Dipper to find it. 31 00:02:23,040 --> 00:02:28,040 Very good. But when the Vikings sailed in the summer months, they would have had difficulty finding the North Star. 32 00:02:28,040 --> 00:02:29,040 Why is that? 33 00:02:29,040 --> 00:02:34,040 Because Norway is so far north, there are places where the sun never sets in the summer. 34 00:02:34,040 --> 00:02:36,040 That's why it's called the Land of the Midnight Sun. 35 00:02:36,040 --> 00:02:39,040 Even in southern Norway, it doesn't get really dark at night. 36 00:02:39,040 --> 00:02:43,040 Dr. D., how would they navigate without a compass or the use of the stars? 37 00:02:43,040 --> 00:02:46,040 Lots of ways. For example, they relied upon landmarks. 38 00:02:46,040 --> 00:02:53,040 They used ocean currents, prevailing winds and swells, and they observed the migrations of birds and whales to find their way. 39 00:02:53,040 --> 00:02:55,040 Is it possible that they used the sun? 40 00:02:55,040 --> 00:03:00,040 Yes, they apparently used the sun's shadow and the rising and setting positions of the sun to find north. 41 00:03:00,040 --> 00:03:03,040 Okay, and if there are clouds? 42 00:03:03,040 --> 00:03:09,040 Some people think they used a sunstone to locate the rising or setting sun when there were clouds on the horizon. 43 00:03:09,040 --> 00:03:10,040 I have a piece right here. 44 00:03:10,040 --> 00:03:11,040 How does it work? 45 00:03:11,040 --> 00:03:13,040 It's called Iceland's bar. 46 00:03:13,040 --> 00:03:18,040 Put a dot on top and look through it, you'll see two dots. 47 00:03:18,040 --> 00:03:24,040 You rotate it until both dots are equally dark, then the crystal points toward the sun. 48 00:03:24,040 --> 00:03:26,040 That's pretty ingenious. 49 00:03:26,040 --> 00:03:34,040 Of course they would have loved modern navigational technology like this sextant, a seagoing clock, or especially a GPS. 50 00:03:34,040 --> 00:03:37,040 Our GPS, however, is causing us some problems. 51 00:03:37,040 --> 00:03:38,040 What do you mean? 52 00:03:38,040 --> 00:03:42,040 It's giving us lots of random coordinates, even when we're not moving. 53 00:03:42,040 --> 00:03:45,040 Interesting. It makes it hard to find a cache. 54 00:03:45,040 --> 00:03:50,040 I have a friend at NASA Langley Research Center who works a lot with global positioning systems. 55 00:03:50,040 --> 00:03:53,040 I'll email you his information. I'm sure he can help you. 56 00:03:53,040 --> 00:03:57,040 Until then, I can tell you where to get a good sunstone. 57 00:03:57,040 --> 00:04:02,040 Thanks, Dr. D, but after I finish my research, I think I'll just give him a call. 58 00:04:04,040 --> 00:04:06,040 What about this one? 59 00:04:06,040 --> 00:04:10,040 If we were putting Jacob's bike in our cache, I'd say great. 60 00:04:10,040 --> 00:04:12,040 Remember, we have to hide this when we're finished. 61 00:04:12,040 --> 00:04:15,040 Plus, I'll never get that on the plane. 62 00:04:15,040 --> 00:04:21,040 Hmm, I wonder what my profit margin would be for these plastic containers in a yard sale. 63 00:04:21,040 --> 00:04:25,040 Note to self, investigate long-term investment potential in plastics. 64 00:04:25,040 --> 00:04:28,040 Did you read Bianca and Jacob's get-up-and-go sheets? 65 00:04:28,040 --> 00:04:33,040 Yes, and we still need to learn about how satellites and GPS work if we want to complete our assignment. 66 00:04:33,040 --> 00:04:36,040 Dr. D mentioned talking to a friend of his at NASA. 67 00:04:36,040 --> 00:04:39,040 Yes, maybe we can meet him after we finish making our geocache. 68 00:04:39,040 --> 00:04:42,040 And finding supplies for your camping trip. 69 00:04:42,040 --> 00:04:47,040 By the way, how is it possible that you get to go on a camping trip to Colorado? 70 00:04:47,040 --> 00:04:48,040 Isn't that expensive? 71 00:04:48,040 --> 00:04:53,040 These, Catherine, are the benefits of being on the board of a high-profile financial institution. 72 00:04:53,040 --> 00:04:56,040 You're a member of the board? 73 00:04:56,040 --> 00:04:59,040 Well, no, my mom is. 74 00:04:59,040 --> 00:05:01,040 She's taking me camping after our meetings. 75 00:05:01,040 --> 00:05:04,040 I'll tell you all the details when you take me to the airport. 76 00:05:04,040 --> 00:05:07,040 I can't take you to the airport. I can't drive yet. 77 00:05:07,040 --> 00:05:09,040 Oh, right. 78 00:05:09,040 --> 00:05:15,040 Note to self, also investigate investment opportunities in transportation companies. 79 00:05:19,040 --> 00:05:23,040 So what's up? How will the treehouse detectives find the geocache? 80 00:05:23,040 --> 00:05:26,040 What should they do if their GPS devices go out again? 81 00:05:26,040 --> 00:05:31,040 Find out in the next exciting chapter of The Case of the Technical Knockout.