foreign [Music]
Mr Brown here the weather is getting really warm where I am so I grabbed
all of our summer toys from the garage it seems like winter had just got started but
somehow it's already summer again the cycle of the seasons is one of my favorite Cycles
good question squeaks a cycle is kind of a pattern it's a list of steps that happens in
the same order over and over again some Cycles repeat every year like the cycle of the seasons
from Spring to Summer to fall to winter and back to Spring again and other Cycles are shorter like
the cycle of the moon which looks like it grows bigger and smaller every month why don't I take a
break and we can learn about some other cycles that we've talked about here on scishow kids
awesome well why don't we start with the seasons let's find out why seasons happen in the first
place spring is here now instead of building snow forts and licking icicles we can skateboard and
ride our bikes and we don't have to worry about squeaks getting rusty in the snow speaking of
Seasons you know we have four of them spring summer autumn and winter but do you know why
we have more than one season well we have seasons because the Earth is tilted instead of standing
straight up and down it leans a little bit whoa how's that happen a really really long time ago
billions of years ago scientists think something big hit the earth the impact was so strong that it
knocked our planet over a little bit so now Earth is tilted and our tilted Planet travels around the
Sun completing one full trip all the way around every year I mean that's what a year is the time
it takes for the earth to go around the Sun once and depending on where the Earth is in its Journey
around the Sun our exposure to sunlight changes that means the seasons change that's why we have
four seasons in one one year sometimes during the year part of the earth tilts toward the sun
sometimes it tilts away from the sun when the part of the planet you're on is tilted toward
the sun it's you guessed it summer when it's tilted away from the sun it's yep winter and
when it's in between well the weather's pretty much in between too that's when we have spring
and Autumn they're both a little bit warm and a little bit cool and often windy but if this
season also depends on where on Earth you happen to live that means that not everyone experiences
the same season at the same time it can be summer in some parts of the world when it's winter and
others because those different parts of the planet are getting different amounts of sunlight when
the northern hemisphere is tilted toward the sun it is summertime the southern hemisphere
is tilted away so it's winter time there so the tiltiness of our planet explains a lot it's why
we have seasons and why it's not always winter or always summer all the time and it also helps us
understand why different parts of the world can experience Different Seasons at the same time
that's so cool it might be warm here now but it's winter in the southern hemisphere next what about
the moon earlier I mentioned that the Moon looks like it's changing every month getting smaller and
then bigger and then smaller again why does that happen let's watch another video If you ever look
up at the moon in the night sky say before you go to bed you've probably noticed that as the days
and weeks go by the Moon looks like it's changing shape some nights it's a little sliver and some
nights a few weeks later it's a big bright Circle well the moon doesn't actually change shape but
our view of it does why well the moon just like the Earth has a day side and a night side a part
that's facing the sun and a part that's not so when we see a little sliver of bright moon we're
seeing a little part of the Moon that's facing the sun while the rest of the side that's facing us
is dark and the size and the shape of that sliver of lit up Moon changes because the moon orbits or
it moves around Earth it takes the moon about one month to make one full orbit around the Earth and
as it moves around our planet the daytime Side of the Moon the side that's lit up from the Sun
is facing in different directions as we see it from Earth this means that every night we get
a slightly different view of the Moon and during its month-long trip in orbit around the Earth the
bright part of the moon appears to grow and then shrink from right to left the different shapes
that we see of the lit up part of the Moon are called phases and there are eight phases of the
moon the first phase is the new moon this is when the nighttime Side of the Moon the side
that's facing away from the Sun is what we can see from Earth the Moon is still up there but because
it's the dark side that's facing us we can't see it during the new moon phase the next phase is
called the Crescent phase this is when the Moon looks like a little sliver kind of like the tip
of your fingernail after the Crescent comes the quarter moon this is when the Moon looks like a
half circle and the next phase is called gibbous a gibbous moon is when it's missing just a little
sliver of light and it's almost full and that's what's next the Moon is at its brightest at the
full moon that's when the fully lit up side of the moon is facing us so we see a big bright
Circle but we're only halfway through our phases after the full moon the lit up part of the moon
appears to shrink and just like how it grew from right to left the Sunny Side of the Moon
will shrink from right to left too so after the moon is full it starts to shrink back down to a
gibbous moon but this time you'll notice that the left side is shining bright instead of the right
after the gibbous phase the moon will look like half a circle when it reaches the quarter moon
phase again and then after a few days it shrinks down to a little sliver again the second Crescent
Moon after that the tiny sliver shrinks all the way down until the lit up side of the moon can't
be seen at all now the Moon is a new moon again it's the same old moon but it's gone through a
month-long cycle of phases and it's ready to start all over like I said it takes a a month for the
moon to go through all eight phases in fact our word month comes from the word Moon because it
takes a month for the moon to go from New Moon through all of its phases and back to the new
moon again so tonight before you go to bed take a look out the window if the sky is clear can you
see the Moon if you can what phase is it in is it the bright part of the right side or the left side
as the days go by keep an eye on it and watch how the Moon looks like it's changing shape you can
even make drawings to keep track of how it changes from day to day now you know that the moon doesn't
really change shape we just see different amounts of the Sunny Side of the Moon as it makes its
monthly trip around the Earth hey what do you know the cycle involves the sun too now the cycle of
the seasons and the moon happen over pretty long periods of time a whole year or a whole month but
other Cycles are a lot faster for example there's another one I like called the water cycle it's
all about how water goes from being in a cloud to a raindrop to the ground and back up into a
cloud again let's learn more when you're thirsty nothing is better than a nice cool drink of water
oh and it looks like my plant could use a drink of water too did you ever stop to think about where
our water comes from sure when you get a drink of water it might come from a faucet or a bottle and
I get my flower here water from a watering can but you know what the water that comes out of
the faucet and The Watering Can may once have been part of a cloud or a snowflake or even the ocean
awesome right and it's because of something called the water cycle now a cycle is a set of steps that
repeat over and over when you get to the last step in a cycle you go back to the beginning
and go through the steps again for example every year there are four seasons spring summer fall
and winter and when Winter's over it's time for spring again we go back to the beginning of the
cycle in the water cycle all of the water on Earth goes through a set of steps that repeat over and
over let's start with a step in our water cycle go where we open up our umbrellas squeaks rain rain
is water that falls from the sky some rain water soaks into the ground but a lot of it flows into
little creeks and streams and then ends up in rivers lakes and eventually the ocean and then
something really interesting happens some of this water changes you might have noticed that after
it rains some water is left on the ground like in puddles that you can jump in but what happens to
all that water it seems like it's there one day but then after a little while it's gone well that
water didn't just disappear when the sun comes out and the ground gets warm water can change into a
different form we call this form water vapor and water vapor is a gas the air we breathe is a bunch
of different gases mixed together and like the gases that make up air you can't see water vapor
gas when the Sun Shines on rivers lakes and oceans some of the water changes into water
vapor and then the water vapor goes up High very high up into the sky and it gets pretty cold up
there so when the water vapor gets high enough it starts to get cool and as water vapor cools down
it changes back into little drops of liquid water you can actually see water vapor change into water
drops right at home all you need is a mirror or window and your mouth put your face Close to the
Mirror or window open your mouth nice and wide and breathe out what happens the glass gets foggy
that's because there's water vapor in your warm breath and when the water vapor in your breath
touches the cool glass it changes into teeny tiny droplets a lot of the droplets together make the
glass look cloudy and up in the sky a lot of water droplets together make clouds when there's
a lot of water in a cloud the cloud starts to get darker white fluffy clouds start to turn gray and
as the clouds get grayer the water in them gets heavier when the water gets too heavy it falls
right back out of the clouds as rain and rain is where we started in the cycle we made it all the
way back to the beginning now the water cycle can start all over again all the water on our great
big earth goes through this same cycle over and over it falls to the ground as rain or snow and
soon the water ends up in a river lake or ocean from there it heats up and turns into vapor and
when the vapor Rises into the sky and cools off it comes right back down so the water that you drink
and the water that's in my watering can right now might once have been part of a raindrop that fell
into the ocean on the other side of the world think about that the next time you take a drink
right isn't that neat it takes so many steps just to get a nice
refreshing glass of water are you ready for one more cycle squeaks
awesome because I think this one is especially cool it's about salmon because salmon have
Cycles too every year Well I I'm getting ahead of myself let's watch one more video wow squeaks that
is a tricky riddle can you help me with it what animal goes by seven different names over its life
changes color from stripy to Silver to Red lives in the river and the ocean and what was the last
clue squeaks that's right and is an awesome parent okay hmm oh is it a salmon yes that is a really
good riddle squeaks salmon are amazing animals and they have one of the coolest life cycles life
cycles are the changes they go through as they grow up and live their lives you know how you
were a baby once and now you're a kid and someday you'll be a teenager and then you'll be a grown-up
well salmon go by seven different names over their lives because there are seven different stages of
their life cycle like all fish they start out as eggs that's the first thing they're called an egg
in the fall an adult female salmon lays her eggs salmon usually like to lay their eggs in moving
water like in a river or Street the eggs stay in their safe little spot in the river all winter and
in the spring they hatch at this stage the baby fish are still attached to the yolks of their egg
for food and nutrients this is when they get their second name allevins there are lots of different
species of salmon so depending on which kind of salmon they are the allevans spend a few weeks
or a few months close to where they hatched until they grow big enough to move on to the neck stage
of their life in the third stage of a Salmon's life it's called a fry now it's ready to eat real
food and swim the fry go on little adventures away from their nest but they don't go very far
they stick to the stream they were born in by the end of the summer fry grow into the fourth stage
when they're called par are kind of like teenager salmon almost grown up but not quite par are still
really small but they're getting bigger they swim all around their home stream and develop a special
design on their scales to help them blend in and stay safe from other animals that might try to
eat them the par continue to eat and grow and when they're ready to migrate away from their childhood
home they lose that special pattern on their scales and become smolds now they're in the fifth
stage of their lives this is when the young salmon leave their streams and head for bigger Waters
like rivers and lakes depending on where they are they follow the rivers all the way Downstream to
either the Pacific Ocean or the Atlantic Ocean most salmon are born high in Mountain Streams
so it takes them a long time to get all the way to the ocean when the smokes start their Journey they
still look a lot like par but by the time they get to the water that joins the ocean they're big
and silver to blend into their new surroundings now they get their sixth name they're adults all
different species of salmon live together in the ocean in big groups called schools and they can
live there for a really long time for up to eight years after they've lived their whole adult life
in the ocean something really amazing happens it's time for the salmon to have babies this
is when Salmon enter their final stage of life when they're known as spawning adults spawning
means they're about to lay or fertilize eggs but do you remember what we said earlier about where
salmon eggs hatch that's right salmon are born in Mountain Streams so how do the adult salmon
living in the ocean lay their eggs all the way at the tops of Mountain Streams this is why squeaks
gave us the clue that salmon are amazing parents when Salmon are ready to have babies they remember
where they were born and make the same long journey they made when they were Smalls only
this time they do it backwards the adult salmon leaves the ocean and swim back up Rivers they swim
for hundreds of kilometers against the current of the river they have to jump over waterfalls
and sometimes even dams it's a really tough trip this is when the salmon can change from Silver
to red and some kinds of male salmon even change shape some of them develop a lower jaw that sticks
out like a hook and a big hump on their back after all these changes and years swimming in big rivers
and then oceans and then Rivers again spawning salmon returned to the exact same stream where
they were born to lay and fertilize their own eggs and then the salmon cycle of Life Starts
all over again after the spawning salmon lay their eggs in the fall the eggs will hatch in the spring
with new baby elephants that was a great riddle squeaks salmon are so interesting to learn about
watching those videos was a ton of fun but I can't wait to get outside to play thanks for learning
about Cycles with me and squeaks everyone and we'll see you next time here at the fort [Music]