Neil deGrasse Tyson Explains Why Earth's Surface is Smooth

Chuck yes got another one for you uh-oh oh when I'm trying to trying to bring bring wisdom and enlightenment to you I love the wisdom and enlightenment it's just that I never know what to expect where he's coming from or where it's gonna come from this one is I got earth all right I all manner of spheres in my office yes this is a moment let me yank this off it's my favorite planet it's my favorite planet too oh good yeah the difference is of course in space it doesn't look like this because in space there are no color-coded country in space there is ocean and land and clouds nice and as as nature intended earth to look it's funny how it works out that way so I just wanted to impress upon you how smooth Earth actually is okay we think of it as well how could it be smooth it's got hills and mountains valleys valleys and and oceans and trenches in the ocean that's right and all this and so and even this globe itself it has bumps on it does all right so let's go to the the biggest bump range there would be like just above India and Nepal okay we get the Himalayas last right so you feel that okay all right so there it is right so they're trying to tell you yeah earth is not smooth last about this is where the China and so it's not only there you get it in like the Apennines and the and the Rocky Mountains are over here of course in the United States and it's not slightly high as high the Appalachian the Appalachian Mountains of course right so we get a little bump some are bigger than others okay right so they're just trying to give you the essence of the fact that earth is not smooth yeah but I'm telling you earth is smooth okay earth is so smooth so how smooth is that that if you were some giant and your finger was actually this big right relative to earth okay if you close your eyes and rubbed your finger across earth right it would be one of the smoothest things you ever touched so you're saying that we wouldn't feel these little representations let me tell you why I don't think so okay okay first of all the actual height of these mountains if earth were this size mm-hmm would be about the height of the the depth of your fingerprint oh wow and that's nothing that's nothing right that's nothing and so therefore what how much are they lying to you here I will tell you okay okay so you know how high Mount Everest is okay you know huh no I don't know okay I know it's high I know the actual you can't just recite 20,000 feet 28,000 feet above sea level okay not not above the land around it right above sea level okay okay all right so this bump oh by 20,000 feet how many miles is that you know five and a half maybe five and a half six miles right somewhere in there in there five between five and six miles right if you calculate how big this bump would be given the size of the earth be 83 miles high this bump yes that's pretty wild okay right 83 months 83 miles yeah yeah yeah so this is lyin to you right and almost all geologic globes that give you the bumps in the ridges and I think they're lions it's a little exaggerated a lot exactly exactly a lot exaggerated mm-hmm so this feeds our belief that somehow earth is a very trained place right not only that what is the highest point on earth surface uh above sea level that would be where that ago where'd you go there you go that'd be Mount Everest you know the lowest point on Earth's surface the trench trench let's go around to the trench or I could have gone the short way okay the Marianas Trench you just picked up a lot of frequent flyer miles right it's off the coast of the Philippines okay okay so that's where the Philippine Islands there so that goes down something like thirty thirty five thousand Pheebs like six miles okay okay so that means the all variations in elevation on earth from top to bottom top to bottom can be contained within a dozen miles right that's not a lot it's not a lot not at all a dozen all right doesn't matter how wide are we again we're in miles here sorry for you metric folks yes it's that by the way ketchup yeah if you are in the metric system get with the program America he was American nerve damage so so I know if you only have about a dozen miles across a diameter of 8,000 miles that's the diameter of the earth that is small net that is so small if you shrunk this shrunk earth down to a cube all right for in billiards maybe one of the smoothest cue ball ever built right ever yeah again you rub your finger on a cue ball channel feeling you feel nothing you don't feel nothing and as what would happen if you did it on the earth here so that's all I'm trying to say earth is a very a very smooth sphere Wow see now there will be people who will say you are wrong because I can see mountains and you were wrong because I can see bow yes because you are littler if you were an ant right crawling on a beach there's a man this hills and down these dunes are amazing are you just walking across them as a human being right so it's just a matter what's your sizes this is part of the problem with flat earthers because we are so tiny you're only seeing such a small section of this huge curved surface it doesn't come to you across to you as it's a curved surface right because your exposure to it is so small so this is part of what the cosmic perspective is just rethinking how the world looks to you and ask is there something fundamental about that or are you are you stuck thinking something is true that is not we're thinking something that is not true that is right and so with respect to other planets that we know of I'll say in our neighborhood forget her forget exoplanets that we found how smooth are we compared to them excellent question so it turns out the moon is slightly less smooth than we are ok so they're big mountains relative to the moon's diameter are a little higher okay so you know why okay why he's not as much gravity there ah what you know what the ultimate limit on how high amount it's gonna get on the moon is how much the damn ways right all right and you hold it with just rock rock ain't infinitely strong right exactly all right so at the base of the rock is it can it hold it up or will it start to succumb under pressure and flatten out and so yeah there's a limit to how high the mountains will ever be on the earth just for that reason Wow yeah yeah and you never think of that you never think there's a reason why mountains can only be so high right so and that the smaller the object is or the less gravity it has the more you can have a distortion relative to its size and that's why there are some asteroids that potato-shaped yes all right they're not spheres right because they're rocks can get any shape they want without gravity forcing it back into a sphere so anyway we live in Manhattan which is about a dozen miles top to bottom right that's the full difference between the lowest point on Earth's crust and the highest point on Earth's crust Wow you drive that in 10 minute I was gonna say that's not nothing but you can well yes yes nothing right it's nothing Chuck there's the story right yes okay one other quick thing since gravity will prevent mountains from getting very high right you might ask well what object has the strongest gravity of them all okay so you get neutron stars right that's real which is a failed black hole it'll fail black hole yep and they don't want to be called that but that's so nutri start very severe surface gravity and in fact let me tell you severely gravity if you had a sheet of paper mm-hmm on it the thickness of the paper to ascend the width of the sheet of paper we'd be like you climbing a cliff face and the energy you'd have to expend to do that Wow so in fact neutron stars don't let anything get too far out of alignment they're a little clingy neutron stars are these smoothest objects in the universe Oh for that reason because of the gravities our gravity yeah it's almost like it's compact you don't grab you want to do it wants to pull every part of it as close to the center as possible come here I love you and if something's a little sticking up a little do i yank it back in that's right get in line so so do you have it earth and it's bumps and Wiggles okay you go the earth smooth but not flat

Channel: StarTalk

Views: 226,064

Rating: 4.9235296 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, why is the earth smooth, smooth earth, earth, surface, geography, topography, chuck nice, neutron stars, stars, neutron, neil degrasse tyson explains, globes, classroom, chuck nice neil degrasse tyson, explain, explainers, how high can a mountain be, mountain, how high can a mountain get

Id: C69xx2bM8IA

Length: 8min 56sec (536 seconds)

Published: Tue Mar 24 2020