Neil deGrasse Tyson: The Sun Doesn’t Always Rise In The East

jerk yes Neil what's happening it's that time again it is that time at that time for explaining it's that do some splainin to get some splainin photo anything but eating you lately so here's the thing had a little conversation somebody said to me as surely as the Sun rises in the east and sets in the west as if to punctuate their point and I said well how sewer are you okay since that's the qualifier house that's the qualify if that is the fact right that is supposed to give credence to some other thing they're telling you right that's your eye this matters it does matter okay so this this idea that the Sun rise in the east and I don't know where it came from it's like broadly true but it's it's so not true most of the time oh that I'm that I'm surprised it has persisted to this day wow that's a big statement it's so not true most of the time right that it shouldn't be considered you know an axiom or be considered like a verbal Canon right that's not hanok yeah it's a canon of communication no which in my opinion I don't think it should be so it turns out there is one place on earth where the Sun always rises exactly due east and sets exactly due west one place well one one one one zone on earth's equator if you live there mm-hmm the Sun will always rise due east and set due west every day of the year gotcha if you live anywhere north or south of that all the way up to and down to the Arctic and Antarctic circles right Yuma you might remember those from high school geography what elementary school geography yeah I didn't I didn't go school that good where that was elementary school doubt that might have been College of me okay it's a college so if you go up to the Arctic Circle right as you move away from the equator the Sun depending on what time of the year will rise farther and farther away from due east and set farther and farther away from due west and what happens when you hit these are that's the Arctic Circle and the the Antarctic Circle which by the way are sixty six and a half degrees north sixty six and a half degrees south if you hit those circles and you step across them there are days of the year when the Sun doesn't rise at all because it never set right and their days the Sun never sets because it never rose with that the opposite of what I just said yes the Sun never Rises because it never sat and the Sun never sets I never ever rose you didn't know right so they're they're they're days of the year where you have 24 hours of darkness and 24 hours of light so the Sun basically when it's all like 24 hours the Sun just moves its way along the horizon to come right on back the other side right so we're where's east it's just oh that's so cool I'm saying it so anyway whoever came up with the statement the Sun rises in the east and sets in the west did not live in the Arctic that's the theory that's like the emu it's the Inuits did not come up with that saying right and the Antarctic penguins would have never said this no exactly right exactly yeah it's like in Star Wars that there's one planet and it's in a binary star system and so they they just see you just see both sons all the time like you never forget to plan edition okay it's it's not like that at all but I enjoy the reference why is it not like that at all okay we don't know whether that planet is tipped on its accent all this is happening because earth is tipped on its axis right if we were not tipped on our axis then the Sun would rise due east and set due west for everybody every day every time all the time tipped right so that little 23 degrees actually keeps the Sun at a place where it looks like it's coming up and down but really it's the fact that we're tilted well it will come up and down it's just not gonna happen duties no reason to west right that's all that's all I'm saying that that's all I'm saying and so so the way it works is the sun's rising point actually migrates across the horizon right and it spends half the year this is for most of the world's population who lives between like 20 degrees north and in 50 degrees north that's most of the world's population lives in that those bands it's north and south by the way so all the the big cities of Australia and South America they're all between like 25 and 50 degrees south latitude and all the big cities in the north or around there in the north latitude so here's how it goes so the Sun will spend half its time rising south of due east and each day it'll migrate to a different point so the next day it'll rise a little closer to do east and the next day a little closer and then one day it's gonna rise to east one day one day one day okay what what day is that that's the first day of spring right okay then it keeps migrating north and the day after spring and right little north it's not too East anymore and then it keeps rising farther and farther and farther north by the way the arc that the Sun takes I might as well throw this in here since we're on the subject is huge when it rises north of due east because it's on an angle and that angle goes way across the sky and high so the Sun is in the sky for many many hours more than half the hours of the day the Sun is up first day of summer right not that ago not that long ago on that day the Sun rose as far north as it ever will on the calendar right and that arc through the sky goes high and it will set as far north of Wes as it ever will on the calendar so you got this arc through the sky now watch this so that arc after the first day of summer starts working its way back and guess what day it crosses due east and west again just take a guess at I think equinox which equinox am I talking about then it's on its way back right so wait what which one is vernal the other one so when it's a is called the September equinox right right otherwise the autumnal equinox if I'm trying to be globally inclusive I'll just say the September equinox because it's not autumn in the southern hemisphere their seasons are reversed for all these same reasons so the Sun sets it will rise due east set to west on September 21st there abouts and keeps going so watch what happens it keeps growing farther for themselves but it's angle it's now lower and lower in the sky and so it's not up for very long oh my gosh okay and then he gets really really low in the ancients were freaking out hey the elections one day the Sun is gonna be such a let's go disappear the earth has eaten the Sun except the horizon has eaten the Sun right so so when is the lowest arc that's the winter solstice all right the winter solstice December 21st right now if you are the ancient people and you worship the Sun and you want to make sure it doesn't keep going you sort of chant and pray and you do whatever you do to make sure the Sun doesn't keep dipping down below the horizon but what you notice is that the sun's movement the arc of the Sun each day slows down and it stops it doesn't keep getting lower Sun stops not literally in the sky the arc of the Sun stops getting lower and then starts back up again what is Latin for Sun I'm gonna say Sol Sol sounds got some soul so what is Latin for stop I'm gonna say cut it out son stop solstice solstice that and remember the armistice you're not 130 years old don't remember it so or nah man that is amazing solstice yeah Don Cornelius and I just wanna let you know man this was a stone gasps join us next time on the Solstice okay for everyone older than 60 that one come on man everybody knows Soul Train is still on TV Chuck is good to period jokes hey man look at this afro I am wearing come that is that you know people been talking about your hair look at for a long way don't they say about your hair like that you don't they say no they say it looks like a Lego piece that attached to your head cuz it's so sure yeah so sorry but see my hair line is all raggedy and gray and stuff and don't ever show us your closet other Lego attachments to have always been so or saying was that the Solstice once you realize okay so I'm not good enough just to start because our props depend on you so what do you want it to do what are you trying to get the son to do you don't want to just stop there no you wanted to go back up and be victorious it takes a few days to realize that the Sun has stopped and now it's on its way back and this became the foundation of many many celebrations right around the world Saturnalia Saturnalia among them and when the uncertain date the uncertain day of the year for the birth of Jesus was going to be put onto the calendar the Christians said Catholic Church said let's put Christmas when people already celebrating that way it'll be an easy conversion for them it'll help them okay we don't go out we'll coop they're all there celebration and that's why December that's why Christmas is that in that time of year December was what exactly um so the solstice also occurs with the north of course because they're two solstices in a year the Sun doesn't keep going north it goes very far north we have very long days and then it comes out so so there you have it and by the way it's and the farther away you are from the equator the wider is the range of places over which the Sun rises and sets okay it's huge it's just huge that's so cool yeah and so whoever says sunrise nice and sets in the west as surely as the Sun rises and sets in the west and now I can say well you're not that short and I guess you're not I guess you're not that sure clearly you're not at the Arctic Circle clearly clearly your your premise does not work at the Arctic Circle sir and what's really cool when you're on the poles okay the Sun rises everywhere okay so so when you're on the pole the Sun just slowly begins to appear but it's always just doing circles around you that's why and and those circles it's like a like a helix like a spiral the circles just kind of rise up oh that's so cool right right that's right and then it just goes in Africa and then it goes below the horizon right but what it means is they're there months at a time we have highly sustained Twilight because there's a point where the Sun is just its own diameter below the horizon Tudor and it just stays there as the Sun goes completely around that's so cool so that's just I just don't want to put that one to rest that the Sun rises in these and sets in the west it just doesn't and that's why Manhattanhenge that day of the year where the Sun rises perfectly aligned with the street grid of Manhattan that doesn't happen every day of the year because the sunrise point is changing and it doesn't happen on the equinoxes because the Manhattan grid is not perfectly aligned east-west gotcha so it's rotated 29 degrees from the grid and so you can do the math and you look it up and you figure it out and that's what I first did 20 years ago and I figured out here is the day where the Sun is gonna set or rise exactly on the grid and then you have Manhattanhenge that's super cool well there you have I love it I love it all right Chuck another explainer in the can that's right and now we know so if you ever say as sure as the Sun rises in the east it means you're not sure it means you're not sure all right Jack I had right here I'm Neil deGrasse Tyson as always meeting you [Music] [Applause] you [Music]

Channel: StarTalk

Views: 274,400

Rating: 4.9208622 out of 5

Keywords: startalk, star talk, startalk radio, neil degrasse tyson, neil tyson, science, space, astrophysics, astronomy, podcast, space podcast, science podcast, astronomy podcast, niel degrasse tyson, physics, Chuck Nice, sunrise, sunset, Sun, Earth, East, West, Arctic, North Pole, South Pole, solstice, binary-star system, Star Wars, Manhattanhenge, does the sun rise in the east, sun rise in the east

Id: DCJJk7LjzSI

Length: 14min 31sec (871 seconds)

Published: Tue Jul 07 2020