WEBVTT 00:00:14.000 --> 00:00:26.000 music 00:00:26.000 --> 00:00:29.000 So I am guilty of being an engineer. 00:00:29.000 --> 00:00:33.000 I work at HP and get involved with lots of technologies. 00:00:33.000 --> 00:00:37.000 And for me the eclipse is about trying out all these technologies. 00:00:37.000 --> 00:00:41.000 Electrical engineering, software, optics, all of those things. 00:00:41.000 --> 00:00:43.000 So it's a great fun time. 00:00:43.000 --> 00:00:47.000 This particular eclipse is fun because it goes coast to coast 00:00:47.000 --> 00:00:53.000 but it's also been a long time since the continental United States has seen any total eclipse. 00:00:53.000 --> 00:00:55.000 It's been since '79. 00:00:55.000 --> 00:00:58.000 And it's rare but '79 also hit Oregon. 00:00:58.000 --> 00:00:61.000 It didn't need to be that way but it was. 00:01:01.000 --> 00:01:05.000 Oregon. But it disappeared off to the north I think. 00:01:05.000 --> 00:01:08.000 I was in Corvallis. We were in Corvallis. 00:01:08.000 --> 00:01:13.000 And drove up here to Monmouth and it was cloudy because it was February. 00:01:13.000 --> 00:01:17.000 February is a terrible time in Oregon to see any astronomical event. 00:01:17.000 --> 00:01:20.000 So it was cloudy. So we're really excited about this one. 00:01:20.000 --> 00:01:25.000 We've been looking forward to it since the '79 activity. 00:01:25.000 --> 00:01:29.000 Some years back I spent time working at Mauna Kea Observatories. 00:01:29.000 --> 00:01:32.000 That's over in Hawaii on the big island of Hawaii. 00:01:32.000 --> 00:01:36.000 At 14,000 feet is this among other telescopes. 00:01:36.000 --> 00:01:42.000 This particular telescope, that's a five story building with a 450 ton dome. 00:01:42.000 --> 00:01:48.000 And then the telescope that sits in there. You can see the staircase to give you some scale. 00:01:48.000 --> 00:01:51.000 So it's really quite a large piece of equipment. 00:01:51.000 --> 00:01:56.000 And my job was to basically throw all the computers in the ocean and start over. 00:01:57.000 --> 00:01:61.000 It was a fun place to work. Real astronomers doing real things. 00:02:01.000 --> 00:02:07.000 These days we have this set up just outside of town on hill near here. 00:02:07.000 --> 00:02:10.000 And we've been doing this for maybe 16 years. 00:02:10.000 --> 00:02:14.000 So a little fiberglass dome and some equipment that we put in it. 00:02:14.000 --> 00:02:18.000 When we built the house we poured a separate concrete column. 00:02:18.000 --> 00:02:23.000 It turns out to be pretty cheap. If you're pouring a bunch of concrete anyway putting in an extra column is easy. 00:02:23.000 --> 00:02:26.000 And then we built the house around it. 00:02:26.000 --> 00:02:32.000 So that the house did not touch the concrete column so no vibration from the house gets to the telescope. 00:02:32.000 --> 00:02:36.000 So we've been doing astronomy out there for 16 years. 00:02:36.000 --> 00:02:38.000 And now we get to do the eclipse. 00:02:38.000 --> 00:02:44.000 So for most of human history until the last 150 years 00:02:44.000 --> 00:02:48.000 we didn't know anything about what was going on out there. 00:02:48.000 --> 00:02:53.000 The stars up there in the heavens were fixed. 00:02:53.000 --> 00:02:55.000 They didn't change ever. 00:02:55.000 --> 00:02:60.000 And people had all kinds of crazy theories about what was behind them. 00:03:00.000 --> 00:03:05.000 But across all time that we saw those stars they didn't move. 00:03:05.000 --> 00:03:08.000 Trees grew. Mountains crumbled. 00:03:08.000 --> 00:03:13.000 All things pass but the constellations are ancient. 00:03:13.000 --> 00:03:20.000 If you were here thousands of years ago you would've seen Orion just like that with no difference. 00:03:22.000 --> 00:03:27.000 All night long with no lights for most of human history 00:03:27.000 --> 00:03:30.000 we looked at these things and wondered what they were. 00:03:30.000 --> 00:03:32.000 And they were not changing. 00:03:32.000 --> 00:03:38.000 Now there were a few things changing in the sky and they took special importance, right? 00:03:38.000 --> 00:03:43.000 Planets means wanderers. That's what the word means. 00:03:43.000 --> 00:03:45.000 Because the planets wandered around. 00:03:45.000 --> 00:03:48.000 There were these extra dots that seemed to move around. 00:03:48.000 --> 00:03:51.000 And they loop-de-looped. They'd do all kinds of crazy motions. 00:03:51.000 --> 00:03:57.000 Right? So Venus and Mars and Jupiter and Saturn those are easy enough to see. 00:03:57.000 --> 00:03:61.000 Mercury is here. A little harder to see. It's usually near the horizon. 00:04:01.000 --> 00:04:06.000 But you had these five planets and they would move around. Everything else would be fixed. 00:04:08.000 --> 00:04:13.000 Of course the sun itself moved across the sky through the year. 00:04:13.000 --> 00:04:17.000 And the moon of course moved. So we have these seven things. 00:04:17.000 --> 00:04:20.000 What else comes in sevens? 00:04:23.000 --> 00:04:25.000 Yeah the days of week. 00:04:25.000 --> 00:04:32.000 So thousands of years ago we named the days of the week for these things that moved in the sky. 00:04:32.000 --> 00:04:36.000 Sunday, Monday, on out to Saturday. 00:04:36.000 --> 00:04:40.000 The other ones map but you have to go through some different pantheons to figure out how they map. 00:04:40.000 --> 00:04:47.000 But the seven days of the week mark the seven things that were in motion and regular in our skies. 00:04:49.000 --> 00:04:52.000 Now every once in a while a comet would come through. 00:04:52.000 --> 00:04:54.000 Not predictable unless you were Edmond Halley, right? 00:04:54.000 --> 00:04:57.000 So he figured out how to predict comets. 00:04:57.000 --> 00:04:60.000 Before him comets were not predictable. 00:05:00.000 --> 00:05:04.000 They'd come by, they'd hang around for a few months, and they'd leave. 00:05:04.000 --> 00:05:07.000 And because bad things happen all the time 00:05:07.000 --> 00:05:11.000 bad things would happen when there were comets in the sky. So it must be the comet's fault. 00:05:11.000 --> 00:05:14.000 It's the comet's fault. That's why things are bad. 00:05:14.000 --> 00:05:18.000 So comets became portents of bad things. 00:05:18.000 --> 00:05:23.000 The one thing that most people could not predict 00:05:23.000 --> 00:05:26.000 unless you were a Mayan or a Druid was the total solar eclipse. 00:05:26.000 --> 00:05:32.000 Every once in a while once in a generation the sun would go out. 00:05:32.000 --> 00:05:36.000 Pretty scary, right? Pretty scary. If you don't know what's going on 00:05:36.000 --> 00:05:39.000 and you're not expecting it and the sun goes out 00:05:39.000 --> 00:05:42.000 you're going to run around in circles and yell and scream 00:05:42.000 --> 00:05:45.000 and all kinds of bad things will happen. 00:05:45.000 --> 00:05:49.000 But indeed if you were a Mayan, a Druid, or an Egyptian, 00:05:49.000 --> 00:05:51.000 and you did do the math 00:05:51.000 --> 00:05:53.000 and these guys were smart enough to do it. 00:05:53.000 --> 00:05:57.000 They could do the math and they could figure out there's going to be a solar eclipse. 00:05:57.000 --> 00:05:59.000 That was big mojo. 00:05:59.000 --> 00:05:64.000 If you were the person who said, you know what? Tomorrow the sun's going to go out. 00:06:04.000 --> 00:06:07.000 But don't worry I'm going to bring it back. 00:06:07.000 --> 00:06:10.000 Alright? That's pretty good stuff. 00:06:10.000 --> 00:06:16.000 So lots of cultures. Lots of ways of dealing with that. 00:06:16.000 --> 00:06:20.000 But predictions are a big thing. So we are making a prediction. 00:06:20.000 --> 00:06:25.000 We are predicting that next Monday we're going to get a total solar eclipse 00:06:25.000 --> 00:06:32.000 right across Oregon right on down through the country and out through South Carolina. 00:06:32.000 --> 00:06:35.000 It's about a 60 mile wide path. 00:06:35.000 --> 00:06:38.000 But you don't want to be really on the edge. You kind of want to be in as far as you can. 00:06:38.000 --> 00:06:43.000 Because you'll get a longer exposure a longer eclipse. 00:06:43.000 --> 00:06:47.000 These guys that are down here in the 60, 70, 80, 00:06:47.000 --> 00:06:50.000 you know if you get 95 percent partial 00:06:50.000 --> 00:06:53.000 so the moon's eating up 95 percent and then drifting back. 00:06:53.000 --> 00:06:60.000 It is not 95 percent of the fun. 95 percent partial is not 95 percent of the fun. 00:07:00.000 --> 00:07:04.000 So something different happens at totality. 00:07:04.000 --> 00:07:08.000 You get different effects, different event, different activity. 00:07:08.000 --> 00:07:12.000 Being down here is not ok, not ok. This is where you want to be. 00:07:12.000 --> 00:07:18.000 We are the first place I think that's got a legitimate chance of seeing the eclipse. 00:07:18.000 --> 00:07:21.000 Let's talk about what this thing is for a moment. 00:07:21.000 --> 00:07:25.000 That's the sun. That's the earth. 00:07:25.000 --> 00:07:29.000 This is the moon. This is high cost equipment, right? 00:07:29.000 --> 00:07:33.000 So da dah da dah ... huh? 00:07:33.000 --> 00:07:36.000 OK. That's the eclipse. 00:07:36.000 --> 00:07:44.000 The moon is getting in the way and blocking the sunlight as it goes across the planet. 00:07:44.000 --> 00:07:46.000 Different times in different places. 00:07:46.000 --> 00:07:49.000 You'll get a shadow in different areas. 00:07:49.000 --> 00:07:54.000 In our case we're going to get the shadow right across Oregon and down through South Carolina. 00:07:54.000 --> 00:07:57.000 Pretty much they all go west to east. 00:07:57.000 --> 00:07:60.000 Because the moon is orbiting this direction. 00:08:00.000 --> 00:08:03.000 The earth is turning this direction. 00:08:03.000 --> 00:08:06.000 Which way is south? Is that south? 00:08:06.000 --> 00:08:12.000 That way is south. We are going 1000 miles an hour this way as the earth turns. 00:08:12.000 --> 00:08:17.000 Alright? The moon is going 3500 miles an hour. 00:08:17.000 --> 00:08:20.000 If you do the math on how far away it is and it takes 27 days or however long 00:08:20.000 --> 00:08:23.000 you do the math and it's 3500 miles an hour. 00:08:23.000 --> 00:08:27.000 You subtract off the earth's rotation you get 2500 miles an hour. 00:08:27.000 --> 00:08:32.000 No I did this wrong. 2500 miles an hour minus 1000 gives us 1500 miles an hour. 00:08:32.000 --> 00:08:35.000 Sorry wrong math. 00:08:35.000 --> 00:08:42.000 So the shadow is going to move along at 1500 miles an hour after you do all that math. 00:08:42.000 --> 00:08:45.000 So in fact if you can see west 00:08:45.000 --> 00:08:49.000 you will be able to see the shadow coming at you at 1500 miles an hour. 00:08:49.000 --> 00:08:51.000 It's a great event if you can see that. 00:08:51.000 --> 00:08:56.000 Or going off into the east if you've got an exposure to the east. 00:08:56.000 --> 00:08:60.000 OK so that's what a solar eclipse is. 00:09:00.000 --> 00:09:03.000 Here's what it looks like from space. 00:09:05.000 --> 00:09:08.000 So we said 60 miles wide. That looks bigger than 60 miles. 00:09:08.000 --> 00:09:11.000 I mean that's a big chunk of the earth here. 00:09:11.000 --> 00:09:16.000 Because if you were here you would be seeing half of the sun. 00:09:16.000 --> 00:09:18.000 You'd be getting a partial eclipse. 00:09:18.000 --> 00:09:21.000 So it's darker, darker, darker, darker, as you get towards the middle 00:09:21.000 --> 00:09:24.000 and then in the middle you get the total eclipse. 00:09:24.000 --> 00:09:29.000 We call that the umbra. It's Latin. Penumbra, also Latin. 00:09:29.000 --> 00:09:31.000 You looked it up what did it mean? 00:09:31.000 --> 00:09:33.000 Shade, OK. 00:09:33.000 --> 00:09:36.000 laughter 00:09:36.000 --> 00:09:40.000 Three types of eclipses, alright? 00:09:40.000 --> 00:09:42.000 So we're going after the total. That's why we're here. 00:09:42.000 --> 00:09:46.000 In that total the moon is completely covering the sun. 00:09:46.000 --> 00:09:49.000 The sky gets dark, we see the corona, the whole thing. 00:09:49.000 --> 00:09:53.000 Partial. The moon is going to slowly cover the sun 00:09:53.000 --> 00:09:56.000 during that phase it's called partial. 00:09:56.000 --> 00:09:61.000 So it's going to go partial to total and then back to partial. 00:10:01.000 --> 00:10:04.000 We get about an hour and 10 or 15 minutes on the front half 00:10:04.000 --> 00:10:08.000 and an hour and 20 on the back half. Something like that. 00:10:08.000 --> 00:10:12.000 Other places in the country like California only are going to see partial. 00:10:12.000 --> 00:10:17.000 The moon will cross over but not ever completely. 00:10:17.000 --> 00:10:20.000 And this is fun to watch and we'll talk about what you can see. 00:10:20.000 --> 00:10:23.000 But this is also where you need glasses. 00:10:23.000 --> 00:10:26.000 We might as well say it now. 00:10:26.000 --> 00:10:29.000 There's nothing weird about eclipses that hurt your eyes. 00:10:29.000 --> 00:10:31.000 It's never OK to look at the sun. 00:10:31.000 --> 00:10:33.000 It's just never OK. 00:10:33.000 --> 00:10:36.000 If you go outside and you stare at the sun you're going to have permanent retinal scaring. 00:10:36.000 --> 00:10:38.000 That's what's going to happen. Don't do that. 00:10:38.000 --> 00:10:45.000 Eclipses are the same thing. If you go stare at this thing this part of the sun is just as bright as it's ever been. 00:10:45.000 --> 00:10:48.000 And if you stare at that you're going to get hurt. 00:10:48.000 --> 00:10:52.000 So that's why we have the eclipse glasses. During partial phase. 00:10:52.000 --> 00:10:54.000 We'll say this again in a few more slides. 00:10:54.000 --> 00:10:57.000 During total you're not looking at the sun. 00:10:57.000 --> 00:10:62.000 So you're looking at the moon, you're looking at the corona, you're looking at everything else. Take the glasses off. 00:11:02.000 --> 00:11:04.000 OK. Annular eclipse. 00:11:04.000 --> 00:11:09.000 The moon's orbit is not circular. It's a little bit off-center. 00:11:09.000 --> 00:11:14.000 Sometimes the moon is a little bit further away when it crosses in front of the sun 00:11:14.000 --> 00:11:18.000 and so it looks a little smaller and it won't cover the whole sun. 00:11:18.000 --> 00:11:20.000 So we get this ring of fire. 00:11:20.000 --> 00:11:25.000 And it's kind of cool. I've seen one. It's neato. You don't get all the total effects. 00:11:25.000 --> 00:11:27.000 It's just a type of partial really. 00:11:27.000 --> 00:11:29.000 But the ring of fire is kind of fun. 00:11:29.000 --> 00:11:33.000 In this case for this eclipse there will be no annular. 00:11:33.000 --> 00:11:36.000 Just partial, total, back to partial. 00:11:36.000 --> 00:11:38.000 When it's total you can look at it. Totally safe. 00:11:38.000 --> 00:11:43.000 What about the timing of it? Is it all at once or what? 00:11:43.000 --> 00:11:48.000 So we will see it here. Only us. It's only our eclipse. 00:11:48.000 --> 00:11:51.000 And then it'll move to Madras and it'll be only them. 00:11:51.000 --> 00:11:55.000 And then it'll move to like Rexburg, Idaho and it'll be only them. 00:11:55.000 --> 00:11:59.000 And it'll take a couple of hours to cross the whole country. 00:11:59.000 --> 00:11:63.000 Yeah. So this is the path across Oregon. 00:12:03.000 --> 00:12:09.000 So Monmouth, Dallas, doesn't quite show up there. But Corvallis does, Salem does, good places to be. 00:12:09.000 --> 00:12:13.000 Lincoln City. A little dangerous I'm not too sure. 00:12:13.000 --> 00:12:17.000 The fog there could get you. Could be great, maybe not. We'll see. 00:12:17.000 --> 00:12:21.000 So that's all good. Madras, awesome if you could get there. 00:12:21.000 --> 00:12:25.000 And on out across the state. 00:12:25.000 --> 00:12:29.000 So Portland no good Eugene no good. 00:12:29.000 --> 00:12:33.000 All of Eugene is going to wake up that morning and go to Corvallis. 00:12:33.000 --> 00:12:35.000 All of Portland is going to split. 00:12:35.000 --> 00:12:41.000 Half of them will go off to Madras. Half of them will come down and go to Salem and then get all bolloxed up. 00:12:41.000 --> 00:12:45.000 So we may be nicely between Salem and Corvallis. 00:12:45.000 --> 00:12:47.000 We may or may not get the massive crowds. 00:12:47.000 --> 00:12:52.000 We will get the crowds of people who have been planning to come. 00:12:52.000 --> 00:12:57.000 So this is a little animation that shows the shadow on the move across the country. 00:12:57.000 --> 00:12:64.000 So Mount Jefferson it crosses right across the top. Detroit is good, Madras, Mitchell. 00:13:04.000 --> 00:13:07.000 You'll notice as we start getting into Idaho 00:13:07.000 --> 00:13:09.000 Boise, no good. 00:13:09.000 --> 00:13:12.000 So if you're in Boise you've got to go north. 00:13:16.000 --> 00:13:20.000 This is faster than it will really happen. 00:13:22.000 --> 00:13:27.000 I won't let it go all the way. But Idaho Falls looks good. Rexburg looks good. 00:13:28.000 --> 00:13:31.000 And then we don't care. OK. 00:13:31.000 --> 00:13:36.000 Back to your question. Why is Madras a little bit better maybe? 00:13:36.000 --> 00:13:38.000 So this is the path now. 00:13:38.000 --> 00:13:44.000 This map is an average cloud amount at 10:30 in the morning 00:13:44.000 --> 00:13:48.000 on the 21st across several different years. 00:13:48.000 --> 00:13:52.000 So that's been brought together to be exactly what we care about. 00:13:52.000 --> 00:13:56.000 And blue is great. Red is bad. 00:13:56.000 --> 00:13:60.000 So California. Awesome, right? All blue. 00:14:00.000 --> 00:14:04.000 No eclipse. But it's going to be awesome weather. 00:14:04.000 --> 00:14:07.000 So they're going to have awesome weather. 00:14:07.000 --> 00:14:10.000 Oregon is not bad, right? Lots of blue there. 00:14:10.000 --> 00:14:12.000 Eastern Oregon. Madras right out here. 00:14:12.000 --> 00:14:15.000 We're a little bit yellower than blue. 00:14:15.000 --> 00:14:18.000 So there's a little bit of a chance 00:14:18.000 --> 00:14:21.000 that our weather won't be quite as good as Madras. 00:14:21.000 --> 00:14:25.000 Remember this is 10:30 in the morning. It's corrected already for time of day. 00:14:25.000 --> 00:14:28.000 But I'm going to take the bet. 00:14:28.000 --> 00:14:32.000 As an astronomer I go out to Eastern Oregon every year. 00:14:32.000 --> 00:14:36.000 To the star party. And it's always the August new moon. 00:14:36.000 --> 00:14:40.000 Oregon Star Party. It's a fabulous event. 500 to 1000 astronomers 00:14:40.000 --> 00:14:44.000 all set up for a week out in the desert. It's awesome. 00:14:44.000 --> 00:14:46.000 Come on out. 00:14:46.000 --> 00:14:50.000 But one in three years we get smoke from forest fires. 00:14:50.000 --> 00:14:52.000 And it wrecks the sky completely. 00:14:52.000 --> 00:14:57.000 So I think we've got a decent place to be. 00:14:57.000 --> 00:14:60.000 You know make the bet. This is a good place to be. 00:15:00.000 --> 00:15:05.000 Rain. So more than just clouds what's the chance of rain? 00:15:05.000 --> 00:15:11.000 Pretty low. You can see us we're over here in this red area so that's decent. 00:15:11.000 --> 00:15:13.000 Madras is even a little bit better. 00:15:13.000 --> 00:15:18.000 Again the thing I'm worried about there is forest fires. 00:15:18.000 --> 00:15:23.000 The first thing that happens on the 21st is the partial eclipse begins. 00:15:23.000 --> 00:15:27.000 A little bit of a bite, then a little more, then a little more, then a little more. 00:15:27.000 --> 00:15:31.000 And it's about an hour and 15 minutes maybe. 00:15:31.000 --> 00:15:34.000 As this thing chews away at the sun. 00:15:34.000 --> 00:15:37.000 And it's fun to watch. Again you're going to need your glasses for that. 00:15:37.000 --> 00:15:42.000 Or we can make pinhole cameras. Other such things. 00:15:43.000 --> 00:15:47.000 When light goes through a tree 00:15:47.000 --> 00:15:50.000 and you end up with dapples of light on the ground 00:15:50.000 --> 00:15:54.000 your mental model is light's going through the tree and it's left little things. 00:15:54.000 --> 00:15:56.000 That's the wrong mental model. 00:15:56.000 --> 00:15:60.000 What's really happening is all those little round circles 00:16:00.000 --> 00:16:03.000 are pinhole camera effects 00:16:03.000 --> 00:16:08.000 from the light traveling through the tiniest of little interstices. 00:16:08.000 --> 00:16:12.000 And those are actually images of the sun on the ground. 00:16:12.000 --> 00:16:15.000 Normally you don't care. They're little round dots. Who cares? 00:16:15.000 --> 00:16:19.000 During the eclipse during the partial phase 00:16:19.000 --> 00:16:24.000 all those little round images of the sun, the dapples of light, will turn into crescents. 00:16:24.000 --> 00:16:28.000 Because again it's a pinhole camera it's making an image of the sun 00:16:28.000 --> 00:16:33.000 on the ground or the wall or the sheet that you lay out or what have you. 00:16:33.000 --> 00:16:35.000 So watch for these things. 00:16:35.000 --> 00:16:39.000 And they'll grow, right? They'll be a nibble and then they'll be half. 00:16:39.000 --> 00:16:42.000 And then it'll be this full crescent over a period of time. 00:16:42.000 --> 00:16:45.000 Easiest thing in the world to photograph. 00:16:45.000 --> 00:16:50.000 So wherever you are don't be out in the middle of a field with no trees. 00:16:50.000 --> 00:16:54.000 Right? As long as you're casting a shadow 00:16:54.000 --> 00:16:56.000 you'll get a good view of the eclipse. 00:16:56.000 --> 00:16:62.000 But be near some trees or something so you can start picking up on this. It's fun. 00:17:02.000 --> 00:17:07.000 If there are no trees or you want something to do for your kids or grandkids 00:17:07.000 --> 00:17:09.000 building a pinhole camera is pretty easy. 00:17:09.000 --> 00:17:15.000 You take a big box. You want it to be pretty big. Three or four feet in size in order to get a big image. 00:17:15.000 --> 00:17:20.000 Tape on some tin foil. Take a pin. Put a hole in it. 00:17:20.000 --> 00:17:22.000 Put a piece of white paper on the back. 00:17:22.000 --> 00:17:25.000 You don't need a hole for your head. You can just leave the bottom out. 00:17:25.000 --> 00:17:29.000 And you'll get a very nice image of the sun. 00:17:29.000 --> 00:17:32.000 If there was sunspots you might even see sunspots. 00:17:33.000 --> 00:17:36.000 So easy to make, fun to do. 00:17:36.000 --> 00:17:42.000 But if you really want to go cheap and simple you can use a colander. 00:17:42.000 --> 00:17:44.000 Anything with holes in it works. 00:17:44.000 --> 00:17:48.000 Including a Ritz cracker or a saltine. They've got little holes in them. 00:17:48.000 --> 00:17:53.000 If you hold them in the right spot you'll see little eclipses from a Ritz cracker. 00:17:53.000 --> 00:17:55.000 So these things are easy to do. 00:17:57.000 --> 00:17:61.000 So that's partial phase. Getting more and more and more partial. 00:18:01.000 --> 00:18:05.000 As you get closer to totality 00:18:05.000 --> 00:18:10.000 minutes, maybe five minutes away from totality, maybe closer. 00:18:10.000 --> 00:18:15.000 An effect called shadow bands begins to happen. It's subtle. 00:18:15.000 --> 00:18:19.000 This is a drawing that somebody made from 1870. 00:18:19.000 --> 00:18:22.000 But they wiggle, they move, they churn. 00:18:22.000 --> 00:18:26.000 It's like if you were looking at the bottom of a swimming pool 00:18:26.000 --> 00:18:31.000 and you see ripples on the bottom of the swimming pool because of the waves. 00:18:31.000 --> 00:18:34.000 I think that's what's going on with the atmosphere. 00:18:34.000 --> 00:18:38.000 As the sun gets smaller and smaller it's more and more pointed 00:18:38.000 --> 00:18:40.000 and begins to show this effect. 00:18:40.000 --> 00:18:42.000 So watch for this. 00:18:42.000 --> 00:18:48.000 That happens again maybe a couple of minutes before totality hits. 00:18:48.000 --> 00:18:52.000 Here's somebody in 2001. They laid out a sheet. 00:18:52.000 --> 00:18:56.000 And picked up on the shadow bands there. You can see them. 00:18:56.000 --> 00:18:59.000 Subtle but interesting to see. 00:18:59.000 --> 00:18:63.000 OK the next thing that happens is the moon is now closing in, right? 00:19:03.000 --> 00:19:07.000 So the last light the sun is going to show 00:19:07.000 --> 00:19:10.000 is Bailey's Beads and or the diamond ring. 00:19:10.000 --> 00:19:16.000 So what's going on is the moon has mountains and valleys around the edges. 00:19:16.000 --> 00:19:20.000 And the sun is going to shine through those cracks. 00:19:20.000 --> 00:19:26.000 So you may get diamond ring to Bailey's Beads or the reverse. 00:19:26.000 --> 00:19:30.000 But you'll start seeing these sorts of things. These are safe to look at. 00:19:30.000 --> 00:19:34.000 When it starts getting to this you can take the glasses off. 00:19:34.000 --> 00:19:37.000 This is ok. It's only going to last for two seconds. 00:19:37.000 --> 00:19:40.000 So it's fast. 00:19:40.000 --> 00:19:44.000 If you miss it you better be looking at the end of the eclipse 00:19:44.000 --> 00:19:47.000 because you'll get another shot at the end of totality. 00:19:47.000 --> 00:19:50.000 So at the beginning and at the end of totality 00:19:50.000 --> 00:19:54.000 Bailey's Beads and the diamond ring. And it's neat they're fun to see. 00:19:54.000 --> 00:19:58.000 Now during totality you get corona. This is the big it. 00:19:58.000 --> 00:19:63.000 If you go to the Louvre what do you want to see? The Mona Lisa, right? 00:20:03.000 --> 00:20:07.000 If you're looking at a total solar eclipse this is what you want to see. It's the big it. 00:20:07.000 --> 00:20:11.000 Every museum has a big it. In our case this is it. 00:20:11.000 --> 00:20:14.000 There may be prominences and flares, they're cool. 00:20:14.000 --> 00:20:17.000 But the sun's kind of quiet right now. We're in a quiet season. 00:20:17.000 --> 00:20:20.000 So I'm not actually expecting prominences and flares. 00:20:20.000 --> 00:20:25.000 But we will see corona. You may see structure in the corona. 00:20:25.000 --> 00:20:29.000 And certainly as a photographer I want to try to capture that structure. 00:20:29.000 --> 00:20:34.000 Around that are stars and other such things. 00:20:34.000 --> 00:20:40.000 This is the night sky during the day at that time of the day. 00:20:40.000 --> 00:20:42.000 So the moon and the sun are right together. 00:20:42.000 --> 00:20:49.000 Right out in here down and to the left a couple of diameters is Regulus. 00:20:49.000 --> 00:20:51.000 Big bright star in Leo. 00:20:51.000 --> 00:20:55.000 So you should be able to see Regulus. That'll be worth doing. 00:20:55.000 --> 00:20:58.000 You may see other stars. 00:20:58.000 --> 00:20:64.000 Mars. So here we are. Sun, Mars, Venus is up there. 00:21:04.000 --> 00:21:06.000 Mercury, Mars, Venus. 00:21:06.000 --> 00:21:12.000 Saturn and Jupiter are not in the daytime sky. Or at least not in this sky. 00:21:12.000 --> 00:21:17.000 So if you're looking for planets, Mercury, Mars, Venus. 00:21:17.000 --> 00:21:21.000 Regulus is the bright star. You may see Sirius it's over here. 00:21:21.000 --> 00:21:24.000 Sirius is the brightest star in the sky. 00:21:24.000 --> 00:21:26.000 We'll see if it's bright enough to shine through. 00:21:26.000 --> 00:21:28.000 The reason I'm saying that 00:21:29.000 --> 00:21:34.000 during totality it is not pitch black. You're not going to stumble around and fall. 00:21:34.000 --> 00:21:40.000 Around the horizon you're going to see sunset all the way around. 00:21:40.000 --> 00:21:43.000 An that'll let some light in. 00:21:43.000 --> 00:21:46.000 And stuff that's further away from the sun and the moon 00:21:46.000 --> 00:21:51.000 is going to be a little mushier a little harder to see because the sky will be a little brighter. 00:21:51.000 --> 00:21:55.000 So you may or may not see Sirius or some of these things that are further away. 00:21:55.000 --> 00:21:59.000 Stars and planets that are in here that's your best bet. 00:21:59.000 --> 00:21:62.000 So again protecting our vision. 00:22:02.000 --> 00:22:05.000 We never look at the sun. 00:22:05.000 --> 00:22:09.000 We're going to wear our eclipse glasses when we're looking at partial. 00:22:09.000 --> 00:22:13.000 When you're not looking at the partial eclipse and you're just eating Cheerios 00:22:13.000 --> 00:22:15.000 you don't have to wear your glasses, right? 00:22:15.000 --> 00:22:17.000 So I've had this question come up. 00:22:17.000 --> 00:22:21.000 Only when you're looking at the partial eclipse do you wear the glasses. 00:22:21.000 --> 00:22:24.000 The other thing that people do that is wrong 00:22:24.000 --> 00:22:29.000 you put them on, you look at the sun, now you're done looking at the sun so you take them off. 00:22:29.000 --> 00:22:32.000 That's not ok. Don't do that. 00:22:33.000 --> 00:22:38.000 Wear the glasses. Safe, don't wear the glasses. Then wear the glasses again. 00:22:38.000 --> 00:22:42.000 You're going to get two minutes of totality. One second shy here. 00:22:42.000 --> 00:22:48.000 We're going to get 119 seconds. 9:05 is start. 11:37 is end. 00:22:48.000 --> 00:22:50.000 And then hamburgers. 00:22:50.000 --> 00:22:55.000 I like these guys. I figure if it's good enough for them it's good enough for us to wear these things, right? 00:22:55.000 --> 00:22:57.000 During the partial phases only 00:22:57.000 --> 00:22:61.000 we're going to use these glasses when we're looking at the sun. 00:23:01.000 --> 00:23:05.000 We're going to get them from reputable places. 00:23:05.000 --> 00:23:09.000 When I first started giving this pitch six weeks ago, two months ago, 00:23:09.000 --> 00:23:15.000 there weren't any bad glasses out there. Just go get them they're fine. 00:23:15.000 --> 00:23:20.000 Now we've got people who are creating bogus glasses and they're not OK. 00:23:20.000 --> 00:23:25.000 The first thing you look for is ISO. Is there an ISO standard? 00:23:25.000 --> 00:23:29.000 What's the number? 12312/2. 00:23:29.000 --> 00:23:33.000 Hardly matters. Is it stamped ISO certified or not? 00:23:33.000 --> 00:23:36.000 People are beginning to counterfeit that. 00:23:36.000 --> 00:23:39.000 So what's a person to do? 00:23:39.000 --> 00:23:42.000 There are some reputable places to get these things. 00:23:42.000 --> 00:23:47.000 Eclipseglasses.com is good. Rainbow Symphony is good. Great American Eclipse. 00:23:47.000 --> 00:23:52.000 These are places that are well-known to have the right stuff. 00:23:52.000 --> 00:23:59.000 You can also get professional astronomy material and make your own. I know people who have done that. 00:23:59.000 --> 00:23:65.000 If you're a welder or have access, number 14 or denser and you're OK. 00:24:05.000 --> 00:24:08.000 It's very chic the helmet, right? 00:24:08.000 --> 00:24:10.000 Pinhole boxes which we've talked about. 00:24:10.000 --> 00:24:14.000 Ritz crackers and the like, also very good. 00:24:14.000 --> 00:24:18.000 The reason why we're not going to use the bad stuff and we'll talk about what the bad ones are 00:24:18.000 --> 00:24:24.000 it might actually look OK. You're going to look through a floppy disc or something, right? 00:24:24.000 --> 00:24:29.000 You might actually say oh it doesn't hurt me, I'm seeing it, it's fine. 00:24:29.000 --> 00:24:33.000 There's infrared, there's ultraviolet, there's no pain receptors in your retina. 00:24:33.000 --> 00:24:36.000 All kinds of not OK. 00:24:36.000 --> 00:24:40.000 So you just don't want to judge based on your own perception 00:24:40.000 --> 00:24:44.000 of whether something is dimming the light enough or not. 00:24:44.000 --> 00:24:47.000 Because there's too many other things that can be going on. 00:24:47.000 --> 00:24:51.000 So sunglasses super dark, not OK. 00:24:51.000 --> 00:24:56.000 If you take two polarized sunglasses and turn them 90 degrees to each other 00:24:56.000 --> 00:24:60.000 they get super dark it's a very cool effect. But it's not good enough. 00:25:00.000 --> 00:25:02.000 So don't do it. 00:25:02.000 --> 00:25:08.000 You know if you use potato chip bags or something you can look through them, not good enough. 00:25:08.000 --> 00:25:12.000 When computer discs were still a thing it would not be OK. 00:25:12.000 --> 00:25:15.000 And a cool one from long ago. 00:25:15.000 --> 00:25:17.000 You take a glass bottle and a candle 00:25:17.000 --> 00:25:22.000 and you put smoke on the bottom of the glass bottle and you look through it. 00:25:22.000 --> 00:25:29.000 But is it even? Has it been smudged? What's it doing with ultraviolet and infrared? 00:25:29.000 --> 00:25:31.000 You know it's just generally not OK. 00:25:31.000 --> 00:25:35.000 The language we use here is permanent retinal scaring. 00:25:35.000 --> 00:25:40.000 And you don't want to have anything to do with it. It's not OK. 00:25:40.000 --> 00:25:42.000 Equipment. 00:25:42.000 --> 00:25:46.000 It is tempting to drag out a lot of equipment 00:25:46.000 --> 00:25:49.000 and attempt a lot of different activities. 00:25:49.000 --> 00:25:54.000 Binoculars. Technically they're OK during totality. 00:25:54.000 --> 00:25:57.000 Because you're not looking at the sun. 00:25:57.000 --> 00:25:61.000 You're looking at the edge of the moon, and the corona, and the sky and other such things. 00:26:01.000 --> 00:26:06.000 But at the end of partial as the sun reveals itself 00:26:06.000 --> 00:26:11.000 if you're still looking into your binoculars it damages fast. 00:26:11.000 --> 00:26:14.000 If you're just naked eye no binoculars 00:26:14.000 --> 00:26:17.000 at the end of totality you see a glimpse of the sun come out, you're OK. 00:26:17.000 --> 00:26:21.000 We glimpse the sun all the time. We glimpse it we don't stare at it. 00:26:21.000 --> 00:26:26.000 But you get glimpses all the time. You're driving, you turn, there's the sun, you see it, you're not blind. 00:26:26.000 --> 00:26:32.000 Naked eye a glimpse doesn't hurt you. 00:26:32.000 --> 00:26:38.000 Binoculars at the end of totality that glimpse that comes out, bad really bad. 00:26:38.000 --> 00:26:43.000 You can get permanent retinal scaring in seconds or less. 00:26:43.000 --> 00:26:45.000 Same with telescopes and such. 00:26:45.000 --> 00:26:49.000 Camera. If you've got a camera, single lens reflex where you're looking into the camera 00:26:49.000 --> 00:26:52.000 and it's part of the optical path and you're shooting like that 00:26:52.000 --> 00:26:57.000 that's not OK, right? Because that optical path will also hurt you. 00:26:58.000 --> 00:26:62.000 If you have done eclipses and you know what you're doing 00:27:02.000 --> 00:27:07.000 and you automate it and you're not looking through it and all of that, fine. 00:27:07.000 --> 00:27:10.000 If it's your first serious eclipse it's only two minutes! 00:27:10.000 --> 00:27:13.000 Don't be messing around with a bunch of stuff because it's going to be over. 00:27:14.000 --> 00:27:17.000 It's like ah, oh no. 00:27:17.000 --> 00:27:20.000 So experience it. Don't get lost in the tech. 00:27:20.000 --> 00:27:25.000 I'm an astrophotographer and we're taking 50 shots of this thing. 00:27:25.000 --> 00:27:27.000 But I'm not touching anything. 00:27:27.000 --> 00:27:32.000 So I've wrapped enough software around this and we've got the dome and the permanent installation. 00:27:32.000 --> 00:27:36.000 I'm going to be off enjoying the eclipse with the group. 00:27:36.000 --> 00:27:40.000 And hopefully the telescope will do the right thing. 00:27:40.000 --> 00:27:43.000 You know I've been testing it now for six months. 00:27:43.000 --> 00:27:47.000 I tested it again this morning. I'm going to test it every day until the eclipse 00:27:47.000 --> 00:27:49.000 so that I know it's going to work right. 00:27:49.000 --> 00:27:52.000 So unless you're doing that kind of stuff don't even think about it. 00:27:52.000 --> 00:27:54.000 Now it's tempting, right? 00:27:54.000 --> 00:27:58.000 You got two minutes, you got your cell phone, you're going to take a snap picture, fine do that. 00:27:58.000 --> 00:27:62.000 It's fun. But otherwise be very careful. 00:28:02.000 --> 00:28:05.000 What about taking pictures during partial eclipse? 00:28:05.000 --> 00:28:08.000 Your camera can catch fire. 00:28:08.000 --> 00:28:16.000 If you've got a nice 50 millimeter lens and you aim it at the sun and you take some exposures 00:28:16.000 --> 00:28:19.000 even though it's a partial eclipse 00:28:19.000 --> 00:28:23.000 that part of the sun that you're taking a picture of is still full strength. 00:28:23.000 --> 00:28:25.000 Right? So filters. 00:28:25.000 --> 00:28:30.000 If you've got a proper eclipse filter for your camera 00:28:30.000 --> 00:28:33.000 then you could do partial eclipse. 00:28:33.000 --> 00:28:37.000 Putting this in front of your camera isn't actually good enough. 00:28:37.000 --> 00:28:43.000 Because your camera has more glass than that and it needs a denser film. 00:28:43.000 --> 00:28:47.000 You can buy those kinds of things and it'll be fine. 00:28:47.000 --> 00:28:55.000 We drug out our little four inch scope. We stuck a proper solar filter in front of it and looked at it today and it was fun. 00:28:55.000 --> 00:28:58.000 A little sunspot coming over the border. 00:28:58.000 --> 00:28:64.000 But unless you're doing front end filters you probably can't do partial. 00:29:05.000 --> 00:29:11.000 The other thing is the old dime store telescopes they used to sell or maybe still sell 00:29:11.000 --> 00:29:14.000 would sometimes sell with an eyepiece filter. 00:29:14.000 --> 00:29:18.000 You would screw a dense little piece of glass onto the eyepiece 00:29:18.000 --> 00:29:22.000 put it into the telescope, and then you'd be able to look at the sun. 00:29:22.000 --> 00:29:29.000 Well what's happening is the aperture of the telescope is concentrating all that light down into that filter. 00:29:29.000 --> 00:29:31.000 Which is going to heat up. It's the only thing it can do. 00:29:31.000 --> 00:29:34.000 It's got to eject all that energy and it's going to do it by heating up. 00:29:34.000 --> 00:29:36.000 They crack. 00:29:36.000 --> 00:29:38.000 And then you've got an instant problem. 00:29:38.000 --> 00:29:43.000 So anybody who's got that still around from whenever 00:29:43.000 --> 00:29:46.000 just throw that filter away. It is super dangerous. 00:29:46.000 --> 00:29:55.000 So partial phases is real sun. Use real filters no matter what you do. 00:29:56.000 --> 00:29:58.000 OK etiquette. 00:29:58.000 --> 00:29:63.000 We're going to be in great mobs of people. That's going to be part of the fun, right? 00:30:03.000 --> 00:30:06.000 If you wanted to do something private, eclipses is not it. 00:30:06.000 --> 00:30:09.000 Not everybody likes Dark Side of the Moon. 00:30:09.000 --> 00:30:11.000 So leave your music at home. 00:30:11.000 --> 00:30:13.000 Don't bang on pots. 00:30:13.000 --> 00:30:20.000 This is the real deal. There are cultures where the dragon is eating the sun. 00:30:20.000 --> 00:30:25.000 And the banging of drums scares the dragon away and the sun returns. And it works! 00:30:25.000 --> 00:30:28.000 laughter 00:30:28.000 --> 00:30:30.000 Every single time it has worked. 00:30:30.000 --> 00:30:33.000 But you know I recommend against it. 00:30:33.000 --> 00:30:39.000 Your eyes are adjusting during these partial phases. 00:30:39.000 --> 00:30:41.000 At first it's full daylight. 00:30:41.000 --> 00:30:44.000 The sun gets eaten away, it's at half. 00:30:44.000 --> 00:30:46.000 Why aren't you seeing half the brightness? 00:30:46.000 --> 00:30:50.000 Because your eyes adjust. Your eyes are fabulous at adjusting for how much light there is. 00:30:50.000 --> 00:30:56.000 So during the partial phases it gets less and less sunlight down to that last little sliver. 00:30:56.000 --> 00:30:60.000 It's only at that last little bit that you're going to start seeing it get dim. 00:31:00.000 --> 00:31:03.000 And then totality hits. Your eyes are adjusted. 00:31:03.000 --> 00:31:08.000 You've been working away for an hour at adjusting your eyes. 00:31:08.000 --> 00:31:12.000 Now you're going to see the sunsets, sure. You're going to see stars. 00:31:12.000 --> 00:31:18.000 But if you've got a flash camera that you're trying with if you're going to use the cell phone 00:31:18.000 --> 00:31:20.000 turn off the auto-flash. 00:31:20.000 --> 00:31:25.000 If you've got porch lights and you're out in your front yard kill the sensors. 00:31:25.000 --> 00:31:31.000 Some places around are killing their parking lights for parking lots and such. 00:31:31.000 --> 00:31:35.000 Because the last thing you want to do is you've worked your way into it, your eyes are adjusting, everything's cool, 00:31:35.000 --> 00:31:38.000 totality sets in, and then the lights come on. 00:31:38.000 --> 00:31:40.000 laughter 00:31:40.000 --> 00:31:45.000 Right? So don't stand under those lights wherever you are and don't use flash photography. 00:31:47.000 --> 00:31:53.000 It's also the worst time in the world during the eclipse itself to ask to look through somebody else's equipment. 00:31:53.000 --> 00:31:57.000 Set that up ahead of time if that's what you must do. 00:31:57.000 --> 00:31:58.000 Logistics. 00:31:58.000 --> 00:31:64.000 So we are swimming in logistics here being in Monmouth and Independence and Dallas. 00:32:04.000 --> 00:32:10.000 And 300 million people tonight are trying to decide if they want to come see the eclipse. Right? 00:32:10.000 --> 00:32:16.000 And 200 million of them live within 500 miles of the center line. 00:32:16.000 --> 00:32:21.000 The Oregon Department of Transportation as of about a month ago 00:32:21.000 --> 00:32:26.000 was saying that they were going to get a million people beyond just the normal Oregonians in to see this. 00:32:26.000 --> 00:32:30.000 And that's going to be Madras and the Willamette Valley. 00:32:31.000 --> 00:32:37.000 Don't let anybody plan to drive up and down the valley that day. So anybody you know. 00:32:37.000 --> 00:32:41.000 That day don't do it. It's going to be miserable. 00:32:41.000 --> 00:32:48.000 We've got people living here in Monmouth. We live a few miles out of town. I'm worried about getting them to the house that morning. 00:32:48.000 --> 00:32:52.000 So anybody of course who doesn't have it preplanned, it's dry camping. 00:32:52.000 --> 00:32:58.000 Bring your own water, bring your own food, and we need to stock up on our stuff. 00:32:58.000 --> 00:32:64.000 This particular traffic jam was in China. It's the world's worst traffic jam in history. 00:33:04.000 --> 00:33:08.000 It was 62 miles long and lasted for 12 days. 00:33:09.000 --> 00:33:12.000 So let's go for it. 00:33:12.000 --> 00:33:14.000 laughter 00:33:14.000 --> 00:33:19.000 So during the morning we're going to get an hour, a little more, of partial eclipse. 00:33:19.000 --> 00:33:22.000 Right? You're going to wear your glasses. You're going to watch the bite grow. 00:33:22.000 --> 00:33:28.000 During the last few minutes of daylight you'll start to notice it being dimmer. 00:33:28.000 --> 00:33:30.000 Start changing colors. 00:33:30.000 --> 00:33:33.000 And your eyes are going to continue to adjust. 00:33:33.000 --> 00:33:38.000 As you get down there, shadows are going to start being crisper. 00:33:38.000 --> 00:33:43.000 Our shadows are kind of mushy because light's coming at us from lots of different directions. 00:33:43.000 --> 00:33:48.000 The sun is actually pretty big in the sky and so our shadows are actually not very crisp. 00:33:48.000 --> 00:33:52.000 As the sun gets smaller and smaller because it's getting eaten away by the partial 00:33:52.000 --> 00:33:56.000 your shadows are going to start getting tighter and tighter. So you can see that effect. 00:33:57.000 --> 00:33:60.000 Leaves as pinhole cameras we've seen. 00:34:00.000 --> 00:34:05.000 Watching for shadow bands we've talked about. Again that's going to be just in front of the totality. 00:34:05.000 --> 00:34:10.000 And then if you can watch it the moon shadow hits at 1500 miles an hour. 00:34:10.000 --> 00:34:14.000 And now you've got seconds maybe two seconds 00:34:14.000 --> 00:34:18.000 to see Bailey's Beads and the diamond ring. 00:34:18.000 --> 00:34:24.000 Now you're in totality and lots of interesting things happen. For one it gets colder. 00:34:24.000 --> 00:34:27.000 We could lose 20 degrees Fahrenheit. I mean it could get cold. 00:34:27.000 --> 00:34:30.000 It's only for two minutes. You're going to be OK. 00:34:30.000 --> 00:34:33.000 But it will get colder. 00:34:33.000 --> 00:34:35.000 You'll see the sunsets. 00:34:35.000 --> 00:34:40.000 Animals and birds and things are going to think it's dusk. They're going to start roosting. 00:34:40.000 --> 00:34:45.000 Corona, maybe some prominences, stars and planets, right? 00:34:45.000 --> 00:34:48.000 I don't think we're going to see zombies. 00:34:48.000 --> 00:34:50.000 And then everything in reverse. 00:34:50.000 --> 00:34:56.000 You get a chance to see it all sort of backwards. So shadow bands again and partial. 00:34:56.000 --> 00:34:61.000 And then when it's all over at 11:37-ish, hamburgers. 00:35:01.000 --> 00:35:05.000 People ask me what if it's cloudy? 00:35:06.000 --> 00:35:10.000 If it's cloudy I guarantee two minutes of darkness followed by hamburgers. 00:35:10.000 --> 00:35:13.000 laughter 00:35:13.000 --> 00:35:20.000 The next eclipse for the United States is Texas in 2024 in April I think. 00:35:20.000 --> 00:35:23.000 People have told me that's not good weather in Texas. 00:35:23.000 --> 00:35:27.000 But Texas up through Maine I think. 00:35:27.000 --> 00:35:30.000 It's going to cross over Niagara Falls. That could be fun. 00:35:30.000 --> 00:35:32.000 This is us 2017. 00:35:32.000 --> 00:35:34.000 That's 2024 Texas. 00:35:34.000 --> 00:35:38.000 The very next eclipse actually is 2019. 00:35:38.000 --> 00:35:41.000 Across southern South America. 00:35:41.000 --> 00:35:44.000 That's a trip. That's a journey. 00:35:44.000 --> 00:35:48.000 The next time it goes coast to coast is 2045. 00:35:48.000 --> 00:35:52.000 That's a long ways out and it's also the next time it hits anywhere near us. 00:35:52.000 --> 00:35:55.000 So that will be Northern California not Oregon. 00:35:55.000 --> 00:35:59.000 But that's out in 2045. That's a long ways out. 00:35:59.000 --> 00:35:66.000 So for us really the next best bet if you want to chase eclipses, is Texas in 2024. 00:36:06.000 --> 00:36:10.000 But what about the width? Some of these bands are wide, some of them are narrow. 00:36:10.000 --> 00:36:14.000 And indeed there's a lot of diversity in these things. 00:36:14.000 --> 00:36:16.000 And diversity in the length of the eclipse. 00:36:16.000 --> 00:36:20.000 We're going to get about two minutes here. I think sometimes they get as high as six. 00:36:20.000 --> 00:36:23.000 So it's all about geometry. 00:36:23.000 --> 00:36:26.000 So how far away is the moon? How close is the moon? 00:36:26.000 --> 00:36:30.000 Is the moon sweeping in from the side? 00:36:30.000 --> 00:36:39.000 So lots of geometry effects control the size and the length of totality. 00:36:39.000 --> 00:36:44.000 So its not a flat Earth, it's a globe. 00:36:44.000 --> 00:36:47.000 And so if we use this one as the globe here 00:36:47.000 --> 00:36:52.000 the stuff that's over there is sort of foreshortened and foreshadowed. 00:36:52.000 --> 00:36:54.000 The shadow will be quite long over there. 00:36:54.000 --> 00:36:58.000 Whereas the shadow right here will be tight. 00:36:58.000 --> 00:36:62.000 And so the moon's distance 00:37:02.000 --> 00:37:09.000 and where it's actually hitting at the time of day at any given spot will change all of that. 00:37:09.000 --> 00:37:14.000 Now one thing is it wouldn't surprise me to see cell phones go down. 00:37:14.000 --> 00:37:19.000 So if you're using your cell phone as your video chat 00:37:19.000 --> 00:37:23.000 and using cell phone wifi. 00:37:23.000 --> 00:37:28.000 If we really do get a million people in this area it will crush the cell network. 00:37:28.000 --> 00:37:32.000 Can you make covers for your binoculars out of a pair of glasses? 00:37:32.000 --> 00:37:38.000 I worry about it because I'm not sure about the multiplying effects of the extra optics. 00:37:38.000 --> 00:37:43.000 Because remember you've got only five millimeters let's call it. 00:37:43.000 --> 00:37:47.000 Your pupil will open to five millimeters for us older folks. 00:37:47.000 --> 00:37:51.000 Seven if you're a little guy. But let's call it five millimeters. 00:37:51.000 --> 00:37:56.000 If you're taking binoculars and you're running that much light down in there 00:37:56.000 --> 00:37:62.000 but again you're only filtering it the same way you filter it for five millimeters 00:38:02.000 --> 00:38:04.000 I'm not sure it's enough. 00:38:04.000 --> 00:38:11.000 So I'd be leery of trying to use this material for the binoculars. 00:38:11.000 --> 00:38:16.000 you might need a denser material again from a professional place to make the proper filter. 00:38:16.000 --> 00:38:18.000 What if you use two pairs of glasses? 00:38:18.000 --> 00:38:23.000 Then it's probably safe for twice the area of your pupil. 00:38:23.000 --> 00:38:24.000 laughter 00:38:24.000 --> 00:38:26.000 So you've got to do the math. 00:38:26.000 --> 00:38:32.000 Playing around with a partial eclipse and the effect of the trees and pinhole cameras, all safe. 00:38:32.000 --> 00:38:37.000 Right? Because you're not looking at the sun you're looking at the images. 00:38:37.000 --> 00:38:40.000 So all of that is safe and all those experiments are good. 00:38:40.000 --> 00:38:57.000 music