Subtitles section Play video Print subtitles hello my name is Michael and welcome to dawn the first and only YouTube channel made by of and for teens who like cooking today we're gonna be talking about babies babies are being born all the time in some countries they're born more often than others this website neil dot fun slash a baby map lights up each country on earth at the same rate that babies are born in that country so as you can see India and China light up a lot if you watch long enough you'll get a little UK blip that's a baby being born I mean not like we don't it's on an exact baby but the country's light up at about the same rate as the country's birth rate so you can really get a sense of where people are being born you know to be honest humans are like one of my top ten favorite animals let's keep talking about humans and how many of them there are with population bracketology this website sets up a bracket of cities and then it's your job to figure out who would win in a battle of who's got the largest population I'm gonna change it from metro area to state population make a new game uh some of these states have a by weeks but let me see here between North Dakota and Illinois Illinois clearly is gonna win it's got big cities it's got Chicago oh when you click Illinois there you go now between Idaho and Vermont Vermont is not very populated but Idaho I'm gonna go with Idaho sure close one all right between New Mexico and Massachusetts Massachusetts definitely has more people and between Idaho and Massachusetts obviously Massachusetts does but between Illinois and Massachusetts that Chicago versus Boston and that Boston metro area is quite expansive but I'm gonna go with Illinois Bob Chicago is like the number three most populated city I will keep playing this on my own time so I don't waste yours we need to move on to outer space specifically people who have been there travels in time and space allows you to look at astronauts from all over the world from every country even the commercial and tourist astronauts right now I have my axes built so that I've got the length of trip on the vertical axis the further down we go the longer the person was in space and the horizontal axis is when their first launch occurred so if we go to the very furthest dot and click on it yuri gagarin first human being in space he only spent point zero eight days in space so he's well didn't have a very long trip if we go to more recent launches you'll see that some of these dots have white circles around them those represent people who are currently in space astronaut scott tingle what's up you obviously eat little bit the astronaut ok astronauts don't just travel through space they also travel through time like we just did my beards longer sure it's different continuity isn't really a priority here at Vsauce headquarters but what is a priority is learning let's take a look at this graph and change the horizontal axis to represent time dilation there is clearly some function that defines how you move through time when you are moving through space and where you're moving through space check this out the world record for longest time in orbit is held by cosmonaut padalka who spent 878 point 48 days flying very quickly around the earth and because of that padalka is about well more than 25 milliseconds younger than he would have been if he'd stayed here on earth that's because of time dilation now when you're in orbit time moves for you at a different rate because of two different effects special relativity and general relativity if you want to learn more about these I highly recommend these books first of all Martin Gardner's relativity simply explained a fantastic but my favorite book that I read in all of 2017 was Lewis Carroll Epstein's relativity visualized just phenomenal but if you want to get even deeper you can go a lot less wrong than getting the Taylor wheeler spacetime physics book just unbelievable explanations we've also got videos linked down below where you can learn more but the gist of it is this when you are orbiting around the earth you are moving faster than people who are just still down on earth at rest relative to you and that means that time moves more slowly for you a person at rest down on earth if they could take a telescope and look at your watch would literally see your watch moving more slowly you would be aging more slowly you would be reaching your date of death slower but also the higher up you go the weaker the gravitational field around you will be and that will cause time to go faster for you these two effects combined into this blue line that we see here this red line represents time dilation due to orbital speed and as you can see the larger your orbital altitude is the less quickly you have to move to not crash into Earth and so the smaller the effect is now this green line represents the general relativity effects the gravity well getting weaker and as it does you move through time faster and faster and faster their combined effect is this blue line labeled net orbital time gain now astronauts in the National Space Station are at about you know this altitude a few hundred kilometers and that puts them on the blue line down here meaning they experience less time than us down on earth that's why padalka is about maybe 30 milliseconds younger than he would have been had he not gone into orbit if you'd like to see how you have been moving through time time orbit will help a lot the University of Surrey created this app and it takes information about your altitude and motion to compare how you have moved through time since installing the app compared to someone who has spent that entire time motionless at sea level fun fact about 3200 kilometers above Earth's surface a little shy of 10,000 kilometers away from Earth's center both effects exactly cancel out and no time dilation is experienced relative to someone at rest down on earth anywho I'm sure you have a lot of questions for instance Michael that's cool but what I don't understand is how long can a zucchini grow I'm glad you asked because the world record for longest zucchini was set by giovanni battista Scozzafava of Niagara Falls he grew Sukie knee two point five two meters in length it's just phenomenal but it's actually not that weird zucchinis like to grow big they just don't taste great when they're large ideally zucchinis are picked when they're young no more than 12 inches long so if you're taking notes don't forget that one I also go back to Lightspeed when you're traveling really quickly all kinds of weird relativistic effects occur okay time dilation happens obviously but also measured whips change here's a relativistic car now I can use this slider here to make the cars velocity slower or faster I can speed it up and notice that as I speed it up the car appears to contract and become thinner and thinner and thinner until at the speed of light boom it is well it doesn't have any measurable dimension in its direction of travel we've heard this before and I've talked about it before in episodes about whether the earth is flat or not to a particle traveling near the speed of light the earth would be measurably flat like a disc but would it appear to be a flat disc no because of an optical illusion known as a Tyrell rotation here's an example from Wikipedia of what that looks like I think this animation is brilliant so on the right we have the actual visual appearance of a cube flying by at some proportion of the speed of light and on the Left we have the contraction the actual width of it that we would measure but notice that at 99% the speed of light it almost is completely rotated so that we see the other side of it here's a way to visualize what a Torrell rotation is and why it happens here's a cube now let's imagine that this cube is just moving right past you at some point it's gonna be right in front of you and then it's gonna move away now normally it would look like this it's not moving very near light speed you can't see the back of the cube I mean you can because this one doesn't have any opaque sides but the point is that material over here isn't reflecting light to your eyeballs we can imagine that this green stick is a ray of light any light coming from this back edge right towards you that's getting blocked by the fact that the cube or the shape whatever shape it is might be opaque but if this stick represents how far light travels in a second and it's got to travel like this to to your eye if the object is moving near the speed of light it might be able to move out of the way of that beam of light and not block it so it will reach you you'll see the back of the object as if it is actually rotated so an object traveling near the speed of light will appear to rotate like that it's only its appearance it won't actually be rotated and if you tried to measure it you would find that its length had contracted let's watch a video of this effect space time travel org has a great one and what you see is a bunch of dice and they're all in a row but then above them a die is gonna fly by I think actually a few died known as dice will fly by in the same orientation but they won't appear to be in the same orientation here they come all right not looking too weird yet but as you'll see the closer they get to us the more rotated they are until boom right there we can actually see the back of the cube even though the back is not facing towards us this relativistic effect is called a Terrell rotation and I love it when it comes to relativistic effects who can forget red shifting and blue shifting of electromagnetic radiation not us right and also not velocity Raptor in this game the speed of light is much much much slower so the normal speed of Velociraptor can move at is quite close to it so relativistic effects occur now here's the level and what I need to do is get to this yellow exit door but wait these bullets are kind of close together I should probably be able to fit through them let me start moving my velocity will change oh and look the entire game level warps according to how length changes which means if I go up the bullets get closer together I can spread them out by moving down now I've got room great whoa whoa whoa whoa okay don't you don't to fall in the water if you ever want to center yourself on your character I think you press C yeah okay there you go I find this interesting but not nearly as helpful press C again to go back also notice that my velocity it's like I'm playing asteroids if I stop pushing the key moving at the same velocity but spacebar will freeze yourself let's save your life many times now let's look at these keys in order for me to open up this lock I need all of the keys to have the same color which means I need to find the velocity that redshifts and blueshifts them so that they match now remember velocity is a vector so there's also a direction to it so I don't just need to have the right speed I need to be moving at the right speed in the right direction all right I'm able to get these two near in color but how do i okay for that one I have to move left and right I think now I'm getting it really to purple oh wait that looked but I want to move towards the bullets all right so moving to the right is the opposite of what I want to do let's see what I can come on change color yes nice and that's how you do it when you are an expert at the ways of the universe I'm gonna leave you with well honestly a bit of motivation we've all heard of the company Arm and Hammer right they were founded 151 years ago the brand was in use about 31 years before the birth of a man named Armand Hammer yeah no relation he had nothing to do with founding the company was a named after him but as you can imagine good old mr. hammer Armand to those who were familiar with him got constantly teased for having a name that sounded like the brand Arm and Hammer so what did he do well when he got older got enough money together to buy enough stock in the parent company of Armand Hammer to become a part owner that's right so Armand Hammer became a board member of Arm and Hammer so my question for you is this what are you doing today that will be strange enough that one day it might be discussed on Daum stay curious stay hungry be sure to pre-heat your oven and as always thanks for cooking Bon Appetit
B1 speed earth time dilation dilation moving velocity Relativistic Effects 3 0 林宜悉 posted on 2020/03/30 More Share Save Report Video vocabulary