Skip to main content
Loading Explore guides…
Astronomy History · Acedra
Home
Explore
Astronomy
Astronomy History
Sign in to save
Chat
If YouTube asks you to sign in, open the video on YouTube.
Watch on YouTube
Reload player
Transcript
56 segments
Copy
Hide video
0:04
hey everyone oh excuse me hmm it's just about bedtime
0:11
oh hey squeaks are you ready for bed oh not sleepy at all huh hmm well you know you need to get plenty of sleep to stay healthy and you know how cranky you get when you don't get enough sleep
0:29
i have an idea how about you get nice and cozy and we can watch a few bedtime stories let's watch some stories about your favorite scientists don't get too excited remember you're supposed to be falling asleep hmm which one should we watch first i know how about the story of dr cecilia payne gaposhkin an astronomer who discovered what the sun was made of
1:01
oh it sure is hot out today i could use a nice cold glass of water to cool down
1:11
you know what an amazing star our sun is even though it's way out in space it can still make us feel so hot that's a great question we know the sun is a star but what is it made of and how do we know that when it's too far away and too hot for us to study up close well it turns out that we can thank dr cecilia payne gaposhkin for that she figured out what the sun is made of back in the 1920s you see back in 1900 everyone thought that stars like our sun were
1:42
made of the same stuff as the earth just hotter like they thought stars had a lot of iron in them a heavy and hard material found in rocks after all there's a ton of iron here on earth and we use it in all sorts of ways like to make buildings stronger and in really tough frying pans but then a girl named cecilia payne was born in england she grew up loving science and by the time she was finishing college she knew she wanted to be an astronomer or someone who studies space the
2:12
trouble is to do that miss payne needed even more school and at that time the people in charge of the universities in england wouldn't let women study space because they didn't think women could be good astronomers boy would she prove them wrong she wasn't about to let anyone stop her from pursuing her dreams so in 1923 miss payne moved to the united states to go to radcliffe college an entire school for women taught by harvard university professors
2:40
then in just two years she figured out that astronomers were wrong about what stars like the sun are made of and she did it by looking at the color of their light
2:52
well sure sunlight looks white or maybe a little yellow overall but really it's made of a bunch of different colors of light mixed together it's kind of like how if you mix blue and red paint you get purple except with light if you mix a bunch of colors you actually get white miss payne was able to look at all the different colors of light coming from the sun using a special telescope and
3:16
because of what she learned in school she could use those colors like a code to figure out what the sun was made of the thing is though doing this is actually pretty hard if you don't have a computer to help you and no one had those back in 1923 when miss payne started at radcliffe which is why no one had done the work she decided to do she had to be really careful and focus as she worked but her attention to detail paid off she discovered that unlike earth which is made of many
3:43
things including a lot of iron stars like the sun are mostly made of just two things they're made of something called hydrogen which you can find on earth but it's usually mixed with other things they're also made of helium the same stuff that makes balloons float all that careful work was more than enough to show miss payne's teachers and her school that she was a great scientist and astronomer so at 25 years old she earned the highest kind of college degree you can get
4:11
a phd and when people earn a phd we call them a doctor so miss payne officially became dr cecilia payne and the first person to earn a phd in astronomy from radcliffe college
4:26
right she was super cool other astronomers didn't believe her amazing findings right away though some even called them impossible and it took dr payne years to convince them that she was right part of the reason for that was that she was a woman and at that time many important scientists still didn't believe that a woman could be a great astronomer which obviously was super wrong and unfair eventually though the rest of the astronomers came around and in 1956
4:53
the now married dr cecilia payne gapashkin became the first woman to be a full professor at harvard university and the head of the whole team that studied astronomy today people remember her as the incredible astronomer who discovered what the stars were made of and in doing so change the way we think about space forever
5:16
yeah she was a pretty amazing scientist and it just goes to show you that if you believe in yourself and work hard you can achieve great things
5:29
yeah i feel pretty cooled off too so let's get back out and enjoy the sun how you doing buddy are you getting sleepy hmm not sleepy yet okay let's watch another one this time let's learn about george washington carver a botanist whose discoveries help keep the soil on farms healthy i see what you mean squeaks your plants haven't grown at all and you said you plant these in the fort every year huh oh hi everyone squeaks was just showing
6:04
me one of his lettuce plants or what's supposed to be a lettuce plant he says he's planted lettuce in the fort's greenhouse every year and it's gone great but this year something isn't working he's using the same soil and the same kind of seeds but his lettuce just won't grow
6:23
i'm sorry squeaks but you know what i know a science story that might be able to help it's the story of george washington carver an amazing scientist and inventor who taught people how to take care of their plants it's story time george washington carver was born around 1865 in missouri in the united states that was a hard time in the u.s especially for black people like george washington carver that's because slavery was still allowed in some parts of the country
6:50
slavery is when someone claims another person is property like you might own a toy or a piece of clothing it wasn't kind or fair but it's a big part of the history of the united states enslaved people didn't have any freedom so they couldn't choose what to do where to live or if they could go to school instead they were forced to do work almost always without getting paid in the u.s many
7:14
enslaved people were taken from different parts of africa where they used to be free others were taken from indigenous communities people who had lived freely in what's now the united states for thousands of years meanwhile most enslavers or people who had slaves had light-colored skin and their families came from europe you're right squeaks slavery can be such a hard thing to think about because it's so unfair and unkind and eventually it did become against the law but it's
7:43
still important to remember and it's an important part of this story because mr carver was enslaved when he was born thankfully slavery became illegal in missouri not too long after that but people were still treated unfairly based on the color of their skin for example many schools wouldn't teach black students so when he got older mr carver had to travel to lots of different schools to get an
8:06
education but that didn't stop him as a kid he loved to read books explore the world around him and learn about nature especially plants he also loved to make art and play piano and as he got older he eventually decided to become a scientist he went to college and studied farming and how to grow food and later he became a teacher one of the biggest lessons he taught people was how to keep
8:30
their soil or the dirt they grow plants in healthy see for years people have been planting cotton in their fields but that cotton was taking nutrients from the soil nutrients are things plants and other living things use to grow and stay healthy you use nutrients too and you get them from your food cotton though was using a nutrient called nitrogen it's found in the air you breathe and in the dirt under your feet and it helps plants grow the problem is since people have been
8:58
growing cotton for a long time there wasn't much nitrogen left so the cotton plants weren't growing that's where mr carver came in he taught people how important it was to change the type of plants they grew for example he taught people that if they planted peanuts one year instead of cotton the peanut plants would put some of the nitrogen back in the soil that's because peanut plants have a special kind of bacteria on their roots bacteria are creatures so tiny you need a
9:26
microscope to see them there are lots of different kinds of bacteria and they do different things like some make your yogurt taste sour and others can get you sick if they get into your body but the bacteria on the peanut plants can take nitrogen from the air and put some of it into the soil for plants like cotton to use later so in a way peanut plants could fix the soil
9:49
oh what did he do with all those peanuts that's a great question thanks to george washington carver lots of people started growing peanuts and other foods like sweet potatoes and mr carver came up with all kinds of ways to use them i mean you can eat those foods of course but mr carver also invented other things made from plants like peanuts he made shampoo lotion and even medicine made from peanuts he didn't invent peanut butter though
10:16
even though lots of people think he did so squeaks i think there is a lesson you can learn here about your plants if you've been planting lettuce every year your soil might not have a lot of nitrogen left in it so what do you think about planting peanuts this year
10:29
i thought you'd like that idea see this is one reason it's important to know about different scientists there's a lot you can learn maybe someday you'll make a big scientific discovery that helps a lot of people squeaks oh it looks like you are getting sleepy after all huh
10:47
if you say so next let's watch our video about charles darwin one of the world's most famous scientists do you remember what he's famous for squeaks that's right he was one of the first scientists to write about evolution let's find out more today is a special day here at the fort we're having a birthday party we're celebrating one of the world's most famous scientists a man named charles darwin charles darwin was the kind of scientist we call a naturalist a naturalist
11:18
is someone who studies plants and animals as they live in nature naturalists don't usually do experiments like other kinds of scientists do instead they simply observe or use their eyes to look around them and learn about the natural world a naturalist might try to find out where snogies like to build their nests or they might write down what time of year a wildflower blooms and they might ask big questions like why are there so many different kinds of living things
11:44
in fact that's a big question that darwin himself asked and the answer to that question along with the rest of darwin's work helps us understand how the plants and animals on earth today are different from those that were on earth a long time ago so let's find out some more about darwin and what he learned charles darwin was born in england over 200 years ago when he was a young man he studied to be a doctor but while he was at school he became
12:09
fascinated with the natural world and he decided that he wanted to study nature one of darwin's friends suggested that a good way to learn about different kinds of plants and animals was to go on a special adventure and that's exactly what darwin did he set off with a ship called the hms beagle and this was no ordinary boat trip darwin and his shipmates sailed all over the world for five years the beagle left england in december of 1831 it sailed all the way around the tip
12:38
of south america to some islands in the pacific ocean past the continent of australia around the southernmost point of africa and arrived back to england in october of 1836. and during this trip darwin's job was to study nature at every place where the ship stopped so darwin took lots of notes on the rocks trees and animals he found all over the world one of the most important stops on this trip was in a place called the galapagos islands which are here located next
13:05
to south america quite close to the equator these islands were formed by volcanoes deep beneath the ocean they're special for another reason too there are kinds of animals found here that aren't found anywhere else on earth like a penguin that likes warm water a special kind of sea lion and a giant tortoise what darwin learned on the galapagos islands was that the living things that fit
13:27
into their environment that is the place that they live have a better chance to stay alive than ones that don't fit quite as well but what's that mean well say there's a bird that eats insects and it's looking for a tasty snack and in the place where this bird lives there's a group of insects some that are green and some that are bright pink the bird is more likely to see a bright pink insect sitting on a green leaf than a green insect sitting on a green leaf the insect's green
13:52
color helps it to hide while the pink insect sort of well stands out so you might say that the green insect fits better into its environment because it blends in better so it has a better chance of not being eaten than the pink insect and if fewer green insects get eaten than pink ones that means that more green ones will go on to lay their eggs and have baby insects which means after a while there will be even more green ones and if this keeps happening over a long time then
14:19
eventually all the insects that hatch in that area will be green because that's what works best there and this same idea is true for other animals and plants too not just bugs and what color they are for example birds who happen to be born with bigger stronger beaks might be able to crack open seeds that birds with smaller beaks can't and if those birds with bigger beaks get more food and
14:40
have more babies then over time we'll see more of those birds with bigger beaks than smaller ones or picture tortoises living in a place where plants grow tall and their leaves are pretty far off the ground in a place like that tortoises that happen to be born with longer necks will have an easier time reaching the leaves that they need to eat so they'll be healthier and have more babies and
15:01
eventually the long neck tortoises will take over darwin believes that over long periods of time living things change to help them fit and thrive in the places where they live darwin wrote this idea about change over time as well as a lot of other ideas in a book and what a book people made a lot of fuss about it they talked about it and even argued about it we're still talking about it
15:23
today and scientists still use his ideas to learn more about how living things change over time so happy birthday charles darwin and thank you for all of your hard work now let's have some cake
15:36
okay buddy let's get you to bed one more okay how about this time we have the scientists tell their own story our friend ariel waldman went on a trip to antarctica to study the microscopic life there and she sent us this video all about her trip
16:01
wow it sure was cold on our hike today
16:07
it was definitely cold squeaks but i doubt it was the coldest place on earth i can think of a few places that are even colder like antarctica down there it's super cold all the time oh and that reminds me i haven't had a chance to watch the video message from my friend ariel waldman she actually went to antarctica and sent me a message all about it do you want to watch it with me squeaks awesome let's check it out hi mr brown i'm so excited to tell you about my trip to antarctica
16:42
it's such a special place and not just because the south pole is there it's the coldest driest and highest up continent on earth in fact most of it's actually a desert because it gets so little rain now when you think of a desert you probably think of a place that's really hot and sandy but scientists actually consider anywhere that's super dry to be a desert and with antarctica the lack of water is because it's so cold in winter the average temperature is around negative 60
17:06
degrees celsius it's why it's covered with snow and ice year-round you might be wondering why i wanted to go to such a cold and dry place well i wanted to check out what lives there sure there are penguins but there's a lot of other life in antarctica life that most people don't know about because it's super small living in and below the ice are tons of teeny living things that we call extremophiles an extremophile is a critter that thrives in a really extreme
17:32
environment like one that's really dry or really really cold what's really neat about extremophiles to me is that they could give us clues to what life might look like on other worlds since most of the other planets we know about also are known to have extreme environments so i wanted to see what's actually living below antarctica's ice and show off these amazing critters to everyone else i spent a little while getting really good at using microscopes and video cameras
17:56
planned my trip and then headed southwards the nearest airport to the part of antarctica that i was going to was at least a five hour flight away and they don't exactly have shopping malls in antarctica so i needed to make sure i had everything i needed with me i packed lots of warm socks and the type of clothes that help you stay dry when you sweat because yeah even though it's really cold in antarctica you can still work up a sweat hiking across the ice and snow there
18:20
i made sure to also bring some moisturizer with me so that my skin didn't dry out in my first couple of days there i got to do some really cool things like i got to actually go in the ocean underneath the ice that surrounds the land i didn't go for a swim of course the water is way too cold there so i actually climbed into this metal structure called the obtube when you're inside it's kind of
18:41
like being in a submarine you're surrounded by all these windows that allow you to actually be able to see out and see what's happening in the water all around you basically you get to experience the world below the ice like all the creatures in the water do there was so much life wiggling about and i heard these weird sounds that sounded like they belonged in a movie turns out they were
19:00
actually the calls of seals it was one of the most memorable experiences of my life but what i really wanted to see was what was living in and under the ice on land so i hiked out to one of antarctica's glaciers to collect samples glaciers are these huge blocks of ice and snow and rocks that don't melt in the summer so i was able to collect chunks of one and bring it back into the lab to look and
19:22
see what was inside it and there were so many amazing living creatures one of my favorites were the tardigrades these are tiny animals also called water bears or moss piglets because you can find them anywhere it's wet including in the water trapped by mosses they basically look like tiny little gummy bears with claws what's really cool about them though is that they're practically indestructible they can survive in extreme conditions that other critters wouldn't be able to
19:47
like tons of sun or very little water i think the thing that surprised me the most were the diatoms they're related to plants but they're technically algae so they're closer to the seaweed that wraps around your favorite sushi instead of being perhaps your favorite vegetable and they live inside these beautiful glass houses that they make for themselves and you can find them in water all over the world but the ones i found had really neat shapes the ones i saw
20:12
looked like perfect little triangles i had never seen diatoms like that before oh and i can't forget about the spirulina they're a type of bacteria but not the type of bacteria that makes you sick they're what's called cyanobacteria that's because they often look blue to us and cyan means blue they were so cool because they looked like moving confetti kind of like a party underneath the ice sadly i couldn't stay at this party forever after five weeks in antarctica i had
20:37
to pack up and go home but i made a fun website with all the amazing creatures that i found you can check it out too at lifeundertheice.org i'm really hoping i can come visit you all at the fort sometime soon until then farewell and stay warm wow what an amazing adventure
20:56
me too squeaks it'd be awesome to visit antarctica someday you're right squeaks we don't need to go to antarctica to find snow and ice we trudged through a whole bunch of it earlier today so we could collect some and see what's living in it with our microscope squeaks and i are going to go look for amazing extremophiles living in our wintery world then we'll probably watch more videos of ariel's antarctic trip wow those microscopic creatures
21:25
were beautiful weren't they squeaks squeaks well it looks like all of those bedtime stories worked i better get squeaks to bed thanks for hanging out with us if you want to keep learning about amazing scientists and having fun with me squeaks mr brown and all of our other friends be sure to hit the subscribe button and we'll see you next time here at the fort [Music] you
Here to help you learn
Sign in to keep a private conversation with your course tutor.
Ask me anything about the material…
Sign in to chat