Name: 相対論的効果 (Relativistic Effects)
Uploaded: 2021-01-14T10:27:56.000Z
Duration: 13 min 1 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

hello my name is Michael and welcome to dawn the first and only YouTube channel

未来進行形

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

字幕リスト動画再生

相対論的効果 (Relativistic Effects)

weird

priority

represent

imagine