Transcript source
CSIRO animates: What is a light year?Transcript
CSIRO Explainer – Light Year – 1080p
[Text appears on centre and bottom of the screen: the biggest thing in the universe, If you try to think of the biggest thing in the universe]
Narrator: If you try to think of the biggest thing in the universe you probably start thinking about moons, planets, stars, and galaxies.
[An animated image of a moon, Saturn, a star and a galaxy scroll across the page and text appears at bottom of the screen: You probably start thinking about moons, planets, stars, and galaxies]
[Text changes at the bottom of the screen below the image of the galaxy: But there’s something much bigger, the space between those things]
But there’s something much bigger, the space between those things.
[The camera zooms out and six galaxies appear on the screen and text appears: Space is so big it’s meaningless to measure in metres or kilometres]
Space is so big it’s meaningless to measure in metres or kilometres. Instead, we use light years.
[Image changes and the word “Light Year” appears across the centre of a salmon coloured screen and text appears: Instead we use light years]
A light year is how far light can travel in a vacuum - not that vacuum, the vacuum of space, where there’s pretty much no matter - in one Earth year.
[Image changes to show an animation image of a vacuum cleaner and text appears next to and below the animation image: 1 light year = how far light can travel in a vacuum]
[Text appears at the bottom of the screen: Not that vacuum, the vacuum of space, where there’s pretty much no matter in one Earth year]
[Image changes to show text in the centre and bottom of a green coloured screen: Light is fast, 299,742.458 kilometres per second, Light is fast. Very fast. About 300 thousand kilometres per second fast]
Light is fast. Very fast. About 300 thousand kilometres per second fast.
[Sounds can be heard of a racing car and the image changes to show an outline image of a Formula One racing car and text appears below: If you imagine how fast a Formula 1 car goes, Light travels 3 million times faster than that]
If you imagine how fast a Formula One car goes, light travels three million times faster than that.
[Camera zooms out to show the background travelling across the screen behind the racing car]
[Image changes and a sum gradually appears on the screen step by step: 299,782.458 kilometres per second x 31,557,607 seconds in a year = 9.460,730,472,581 kilometres]
[Text moves through below the sum: So if light can do 300 thousand kilometres per second, and there’s 31 million seconds in a year, we multiply those together to find that a light year is about 9.5 trillion kilometres]
So, if light can go 300 thousand kilometres per second, and there’s 31 million seconds in a year, we multiply those together to find that a light year is about 9.5 trillion kilometres
[Image changes and a world globe, a moon and two number appears on a green screen, 9,460,730,472,581 and 384,400 and text appears at the bottom of the screen: Head to the moon and that’s only about 384,000 kilometres]
Head to the moon and that’s only about 384,000 kilometres.
[Text appears in the centre and the bottom of the screen: just over 1 light second, That’s just over 1 light second away, but it takes about 4 days to get there in a spaceship].
That’s just over one light second away but it takes us about four days to get there in a spaceship.
[Camera zooms in on the animation image of the globe an animation of a space ship launches off from the world globe and travels across the screen from left to right]
Go all the way to the sun and it’s still only a 150 million kilometres. That’s only about eight light minutes. Not even close to a light year.
[Camera zooms out from the animation image of the globe and an animation of the sun appears and the two numbers at the top of the screen change to read 9,460,730,472,581 and 149,597,870 and text appears in the centre and at the bottom of the screen: About 8 light minutes, Get all the way to the sun and it’s still only a 150 million kilometres]
[Text appears at the bottom of the screen: That’s only about 8 light minutes. Not even close to a light year]
[Image changes to show a galaxy and text appears at the bottom of the screen: The big numbers come in when you start measuring galaxies]
The big numbers come in when you start measuring galaxies.
[Numerals and text appears across the image of the galaxy on the screen: 946,073,047,258,080,000, a hundred thousand light years across]
[Text appears below the image of the galaxy: Our galaxy, the Milky Way, is 100 thousand light years across]
Our galaxy, the Milky Way, is 100 thousand light years across.
[Camera zooms out so the galaxy image becomes smaller and a second galaxy image appears on the right hand side of the screen and the numerals at the top of the screen change to read: 18,921,460,945,160,000, 008, two million light years apart]
[Text appears: below the galaxies: And our nearest neighbouring galaxy is 2 million light years away]
And our nearest neighbouring galaxy is two million light years away.
[Image changes to show an animation image of a block of shops and then the image moves to the left of the screen to show an animation image of a male on the right and text appears below: But sure, keep complaining about how far you have to walk to the shops, Light years]
But sure, keep complaining about how far you have to walk to the shops. Light years.
[The image moves down to the bottom of the screen and animation images of the solar system appears at the top of the screen and text appears below the image: They’re a measuring tape for space, helping us understand just how big our universe is]
They’re a measuring tape for space, helping us understand just how big our universe is.
[CSIRO logo and text appears: big ideas start here, www.csiro.au]