(bright upbeat music) - [Mister C] What time is it?

- [Mister C and Group] It's science time!

♪ Science, science, science time ♪ ♪ Let's all stop, it's just sublime ♪ ♪ One, two, three, four, here we go ♪ ♪ Learn so much your brain explodes ♪ ♪ Lessons so cool, so fresh ♪ ♪ Beats so big, you'll lose your breath ♪ ♪ Learning facts and real cool stuff ♪ ♪ Scream for more, can't get enough ♪ ♪ It's, it's science time ♪ ♪ It's fun, you best believe, explore and learn new things ♪ ♪ Come and join me, please ♪ - I'm Mister C and this super smart group is my science crew.

Working together with my crew makes learning so much fun.

Actually, you should join us.

Let's give science a try with a simple DIY.

Today, we're exploring gravity.

What time is it?

- [Group] It's science time!

- Welcome back to "DIY Science Time."

My name's Mister C, and I'm so excited that you're here to be part of our crew today.

(air whooshes) Today, we're talking about gravity.

That's right!

G-R-A-V-I-T-Y.

(rhythmic clapping) Gravity!

(crowd cheers) And it's super cool because we know that when we throw an object up: (bell dings) It comes back down.

See, gravity is always doing what gravity does.

It keeps us grounded to the earth.

And I want to show you something that's super cool.

This is my robotic gyroscope.

- [Child] Whoa!

- And when I set him here on the table, he tips.

But if I turn on the motor that will spin this red gyroscope here, he will start to have the ability to balance himself.

Gyroscopes are super cool.

And our friend here, Mr.

Robot, is going to show us and lead us the way to the materials that we need for our first experiment.

(gyroscope buzzing) Here we go.

Now we saw him tip just a moment ago, but now that this is spinning... (Mister C laughs) He can walk on his little path.

So the gyroscope is keeping him balanced and he is headed this way because he knows that the materials are thataway.

Are you ready?

Let's get started.

(gyroscope buzzing) (gyroscope squeals) - For today's very down-to-earth experiment, we want to grab a few materials that are safe to drop on the ground.

That's code for not grabbing your Oma's fine china.

Grab these instead.

A large book, paper, pencil, feather, or similar object, ball.

And don't forget to grab the book you definitely do not want to put down, your science notebook.

- A science notebook is a tool that every scientist should have because it gives us a place to record all of our learning.

Taking notes and being organized allows us to be better scientists.

A science notebook allows us to go back and review all of the data and information we've gathered during our experiments.

Plus, it allows us to share results with other scientists who might be interested in learning more about what we've discovered.

Whenever you see the notebook pop up on a screen like this, it's a reminder that this is a good place for us to jot down new information during the show.

I've already added a title and the list of materials for today's activity, but our crew is still going to have lots of information to collect and organize as we go through our experiments.

Most importantly, the more you use a science notebook, the better you'll get at taking notes and recording data.

If you don't have a science notebook already, download a copy of Mister C's science notebook from the website.

- Have you ever wondered why objects like apples fall to the ground or possibly even hit your head while standing outside?

Ouch!

It's because of a little something that we call gravity.

Think of gravity like an invisible glue that holds everything together here on earth.

It's a fundamental force of nature that pulls all objects towards earth.

Without it, we float off into space.

Most importantly, everything has gravity, you, me, your science notebook, even your pet dog.

But big things like the earth have a lot more gravity than smaller things.

And since earth is so big and we're so close to it, it pulls us, our homes, the oceans, and even the atmosphere towards it.

Let's explore gravitational pull.

Everything on earth falls to the ground if we hold it up.

For example, this book?

(book slams) Falls down to the table and the table stops it.

Gravity is pulling it down at 9.8 meters per second squared.

But the question I have for you is: This book is made of paper and here I have an individual sheet of paper.

Which of these objects is going to hit the table first?

Are you ready?

Here we go.

Three, two, one.

(book slams) The book hits the table first, but they're both made out of paper.

Hmm!

That's right.

This has to travel through air and so does this, but because the book is more rigid, it allows it to keep its shape and fall straight down.

(book slams) The paper was slicing through the air repeatedly until it comes down to the ground.

But what if we take this paper and crumple it up?

(paper crumpling) Do you think now that the paper and the book will hit at the same time?

(book slams) And they do!

Isn't that cool?

Is there another way that we could possibly make the paper fall at the same rate?

I've got an idea.

What if I take a sheet of paper and fold it in half?

Now this paper is folded in half and it fits almost exactly on top of this book.

But let's test something really quick.

All right, the paper's folded in half.

Let's see.

- [Mister C and Group] Three, two, one!

(book slams) - Now the paper, did you notice, it actually fell more quickly and hit the table pretty much after the book, but it wasn't as long as the open sheet of paper.

But what if we now take the same sheet of paper and put it on top of the book?

Here we go.

In: - [Mister C and Group] Three, two, one.

(book slams) - It falls exactly at the same rate.

And that's because the big, heavier book, the one that has more mass, it's more rigid, is pushing out all the air that's in the way.

And now this isn't dealing with air resistance, so now it falls at the same exact rate.

(book slams) Isn't that awesome?

That's so cool!

Now here's the question.

I had a feather and it blew away a moment ago from the air being pushed away from the book.

I saw it go.

Now, what if this feather is dropped next to this book?

Let's just use the book again.

In: - [Mister C and Group] Three, two, one.

(book slams) - The feather takes a longer time to fall and it's not because the mass of the feather is less, it's because it's dealing with air and it's floating down to the table gently.

Let's try it with a penny.

Feather versus penny.

Here we go.

In: - [Mister C and Group] Three, two.

- Whoop!

I'll hold it like this.

- [Mister C and Group] Three, two, one.

(penny thuds) - The penny hits the table first.

So the question is: Is there something that we could do to make this feather and this penny fall at the same rate?

What if there was no air in the room to prevent the feather from being interfered with from air resistance?

Do you think that these two objects would fall down at the same rate?

This is my setup.

We have a vacuum chamber and a vacuum pump.

A vacuum pump pulls the air out of the chamber as it evacuates the atmosphere, the air that's in there currently.

What we're going to do first is I'm going to show you.

I'm going to blow up a balloon just slightly, just really small.

Now there's a small amount of air inside of this balloon, and what we're going to do is I'm going to tape it to the bottom of the chamber.

(bright music) - [Singer] Woo!

- I'm going to close this and have this open so it can pull the air out.

- [Mister C and Group] Three, two, one.

(engine buzzing) - Isn't that awesome?

You're probably wondering, "Why didn't it fill up the entire chamber?"

Well, it would've, but the little hole where the air is being evacuated from, it blocked it so it can't get any more air out of the chamber.

But what's really interesting is you saw the balloon expand.

That's because the gas inside the balloon wants to expand and fill up as much space as it can, and because there's less air in the chamber, it's able to get bigger.

And when we put the atmosphere back in here, (air hisses) the balloon goes back to its original shape and size.

So what we're going to do is I'm going to connect a magnet over here.

So I have a magnet in there now, and then I'm going to put the feather in there as well.

- [Singer] Woo!

- I'm using the magnets to hold items to the top of the container.

And right now, if I lift the magnets up, this magnet's going to drop, the other magnet's going to drop, and it's going to release the feather.

So let's see how these objects behave inside of there with air.

In: - [Mister C and Group] Three, two, one.

(magnet clatters) - And you could see that they all fell down to the ground, but the magnets hit first and then the feather came in second.

So now the question is: What if we evacuate the vacuum chamber, pump out all the atmosphere, should they fall at the same rate?

Let's try it.

(bright music continues) - [Singer] Woo!

- Open this valve and we're going to pump out the air.

(engine buzzing) All right, here we go.

So we have a magnet connected to the paper, just holding it up, and then the feather is connected to the magnet again.

Here we go.

In: - [Mister C and Group] Three, two, one.

(magnet clatters) - That is amazing.

Without the atmosphere, these objects fall at the exact same rate.

Gravity's pulling down on everything around us.

It doesn't matter if you're a feather, doesn't matter if you're a magnet, it doesn't matter if you're a human, gravity is pulling us down to earth.

And without the air resistance, things fall at the same exact rate.

- Black holes have the most amount of mass out of all objects in our known universe.

This makes their gravitational pull so strong that nothing can escape it.

Even light, traveling at 186,000 miles per second, can't escape the gravitational pull of a black hole.

- This here is a piece of string.

That string is this string, it's the same string, but when I let go of the string, it falls.

And it falls because there's no tension holding the string up.

And this string here uses tension provided by these little plastic strips, and I layer them repeatedly in a pattern all the way up the tower and it provides tension on the string, which makes the string stand up straight.

Isn't that awesome?

So I was thinking instead of building this tower specifically, we're building another tensegrity structure using these little tubes.

Now, if you don't have tubes like this, you can use a variety of things that you might have at your house.

It could be anything.

So the first part, we're going to build basically a U-shape or like a field goal post.

So we're going to take some glue and I'm going to just add a little bit of glue down the center.

And really, once you get it on there, you can just kind of roll it together a little bit into each other, and then the glue is going to roll to the center, and that's going to allow all the glue to come through to the other side, and then we're going to have a nice solid piece.

(mellow upbeat music) (bell dings) Now for this one, on this backside, on the second one, I actually need to put a string on.

So I'm going to slide the string right between these two straws.

There's already a little glue in there, so it's going to hold it in place.

I'm going to go about a half inch from the end.

I'm going to do that on both sides.

So now that we have the string attached, we're going to add the second part to our U. We want the strings to be facing upwards when we glue.

(computer beeps) We'll also build an L bracket using two three-inch pieces and two four-inch pieces.

And we're going to glue the short side to our bracket here so that the long side is coming off.

So we got the first one that's drying, and for the second one, we want the strings to be facing up when we glue.

And now what we have to do is I'm going to take this and I'm going to flip it upside down so the strings are falling down, and I'm going to glue the string onto the bottom part.

I'm going to try to make them the same on both sides so that they're level.

Now I've got to let this dry, but because it's there, I don't have to hold it.

(bell dings) Put a little bead here, about a half inch.

I'm going to hang this over the top.

Just going to let that get into the glue.

All right, now we have to flip it over and we have to glue the last part.

Now, this is what I'm going to do.

Because I'm working on this myself, it's kind of tricky to hold it with one hand.

So I'm going to take that string and put it underneath those tubes and sort of center it.

And now you can see that there's tension.

Going to grab this, flip it over, I'm going to put glue right here in the center, and that's going to hold that string where I just had it.

And it's going to take a second for it to cool.

(bell dings) All right, I think everything is glued.

Now you tip that over and: (Mister C laughs) That's so awesome!

That's so cool!

It's defying gravity.

I mean, look!

It's just floating.

And what's really cool because it's under tension, you can push down like on the front here and it just snaps back together.

The tension working together with the rigid components of the little tubes allows us to have this beautiful structure.

I think you should give this a try as well.

It's super fun, and now you have this beautiful piece of architecture that will defy gravity in your home and will be a talking piece for you, your friends, and your family.

- Gravity holds everything on earth to its surface and even keeps earth in orbit around the sun.

But did you know that you can defy gravity with a simple magnet?

The magnetic force between atomic particles is actually trillions of times stronger than gravitational attraction.

So simply sticking a magnet on your fridge is way stronger than earth's gravity.

Look at us defying gravity!

(pensive upbeat music) (air whooshes) - What's up, crew?

How are you today?

- [Crew] Good!

- I'm so excited because you are going to be responsible for developing and designing an anti-gravity track, and you're going to develop a track that's going to allow that little bouncy ball to travel from the top all the way down to the bottom, but you want it to go as slowly as possible.

We're trying to defy gravity.

The team wasted no time creating tunnels, funnels, and ramps for their track.

- When we started building it, even we had some trouble figuring out what to do first.

And if we hadn't had planned before, then we probably would have spent more time figuring out what we would have done.

Here, hold that.

- I think we both, like, feed off from each other's ideas.

Like, somebody has this idea and then that idea grows into another idea and then that idea grows into another idea.

- Oh!

There it is.

(item rattles) I need a... Oops.

Do this.

Working with a team is better for solving the problem because you have more minds to help find the solution and it'll be overall way more quicker to work with more people rather than just yourself solving the problem.

- What if you strengthen it in here?

- Oh, yeah!

That's true.

- All right!

We are about to test our two anti-gravity tracks.

Are you guys ready to try this?

- [Crew] Yeah!

- All right!

Three, two, one, drop.

(item clattering) 3.78 seconds.

Excellent job.

Excellent job.

All right, here we go.

Let me reset.

Three, two, one, drop.

(item clattering) 5.13 seconds.

Let's go!

Fantastic!

(group applauds) - If I were to change my design, I would use more funnels because they take longer.

They have to go circle, circle, and then they fall down to a ramp or another funnel.

- I would change how much of the space we use because when we built it, we still had a whole lot of space at the bottom left and we could have built more slides to make the time go slower.

(group applauds) - So if you also want to be challenged to build an anti-gravity track, grab some things at home, some cardboard, newspaper, construction paper, tape, lots of tape, and build yourself an anti-gravity track.

The best thing is you can defy gravity slowly by changing that slope of the track, right?

- Yeah!

- You guys have fun trying this experiment?

- [Crew] Yeah!

- So let's challenge all of our friends at home to do it.

And what do we say?

What time is it?

- [Crew] Science time!

(air whooshes) (upbeat music) (ball scraping) - Let's change it up and use the power of gravity to sort some coins.

Mister C 3D printed a coin machine.

This allows gravity to do some of the work while sorting these coins.

When the coins are placed into the funnel, gravity pulls them down.

They then fall into a ring which is turned by gears.

Once the coin travels through an opening that is large enough for the coin, it falls in a stack with similar coins.

G-R-A-V-I-T-Y, gravity.

- Look at this little effervescent tablet.

When I place this into water, it produces a gas, carbon dioxide.

We can use this carbon dioxide, the gas that's being produced, to fuel a rocket, and we're going to use film canisters.

So we're going to take the power of that gas and we're going to put it in here and cap it off, and we're going to allow the top to explode and erupt.

Now, the thing is, is this has projectiles.

I'm going to put on my goggles for safety so that I protect my eyeballs.

(mouth clicks) And practice science safety.

So we're going to take this little container and we're going to add about halfway, a little less than halfway, with water.

I'm going to take, it's about 2/3 of an effervescent tablet and I'm going to place it in there, cap it off, and I'm going to put it right there in the launch zone.

Oh, I can see it expanding.

Oh, you can feel the pressure building up.

(lid pops) Whoa!

Whoa!

(laughs) Oh, my gosh, that was so cool.

(lid pops) Yeah!

(laughing) I think we should try it again, but use less of the effervescent tablet.

All right, I'm going to break this in half and I'm going to break it again.

So a quarter, and that's a small piece.

So those are.

There we go.

Almost thirds.

Let's do three at a time.

We're going to do about the same amount of water, and that way our variable is the size of the effervescent tablet.

There we go.

So we've got three lids ready to go.

And one, two, three.

Cap, close it.

(cap clicks) Cap, close it.

(cap clicks) Cap, close it.

(cap clicks) Now, these rockets are in our launch zone.

That way it doesn't hit any of the cameras or anything like that, but here's what's really cool.

The pressure builds up and it's so much force that the rocket's able to get past the gravitational pull of the earth.

And if it builds up enough pressure, it'll be able to launch.

It's enough force to shoot it up in the sky.

Here we go.

Countdown in: - [Mister C and Group] Three, two, one.

- Again!

- [Mister C and Group] Three, two, one.

(lid pops) - Whoa!

(laughs) That's one of them.

Let's go another one.

- [Mister C and Group] Three, two, one.

(lid pops) - Woo!

Oh, my goodness!

This might be one of those experiments you want to do outside.

(lid pops) Give it a try, change the amount of water, change the amount of Alka-Seltzer, and who knows?

See how high you can make your rockets go and how you can defy gravity and launch things up into the sky, or into your studio.

(lid pops) Whoa!

- Let's explore the center of gravity.

The center of gravity is the single balance point of an object where its entire weight appears to be concentrated and evenly distributed.

Look at this spoon.

It's currently balanced on top of the pencil, but if we add a coin to the system, it tips.

That's because the added weight of the coin changes the center of gravity.

However, with the coin already added to the spoon, we can once again find the center of gravity and balance the spoon on the pencil.

- Ah!

Having a clean space brings me peace.

(bell dings) (gong chimes) (Mister C sighs) I feel so centered when my space is beautiful and clean, and that makes me wonder: Center?

What about the center of gravity?

See, this stick is 36 inches long, and that means the center of gravity is right in the middle, 18 inches.

That's because each side is balanced.

It's the exact same amount of stuff on either side of the center.

The center of gravity is like the part that gravity's acting on the most.

And my broom, well, that is not here in the center.

(laughs) But what if I told you, you can put your hands at the end and now just bring your fingers together and just don't even look at it.

Just bring your fingers together.

Look at that!

Your hand goes directly to the center of gravity.

It's so cool.

You have to try it.

Start off on the outside, grab something, and just you can do it with your eyes shut.

(mellow upbeat music) Isn't that cool?

The center of gravity, it works every time.

You have to give this a try.

- Did you know that mass, the stuff that you're made of, always stays the same?

Mass remains the same everywhere, but weight actually changes based on local gravity.

If you were to travel to the moon where the gravitational pull is weaker, your weight decreases, even though you still have the same mass.

On the moon, you'd weigh about 16% of your weight on earth.

That's about 1/6.

This means if a person weighed 180 pounds on earth, they'd only weigh about 30 pounds on the moon.

Have fun and calculate what you and your crew would weigh on the moon.

It's out of this world!

- G-R-A-V-I-T-Y.

It keeps me on the ground and out of the sky.

What an amazing day.

Tensegrity towers, center of gravity experiments, and free-falling objects.

Wee!

Wasn't it cool to see how the objects fell at the same rate in the vacuum chamber?

No air means no air resistance.

And that tower!

I wonder if you could design your own tensegrity tower using different materials.

How tall could you get it?

Or try building your own anti-gravity track like our crew at McClain.

The designs for that are: ♪ Unlimited ♪ - All right, so I've got my paper and it fits right on top of my half dollar.

I'm going to lift it up.

You can make one of these too.

Grab a coin of your choice, cut out a piece of paper the same size and see if they fall.

In: - [Mister C and Group] Three, two, one!

(coin thumps) - They fell exactly the same and they hit the table exactly at the same time.

How cool is that?

You can do that!

It landed right on my notebook!

Speaking of which, hop online, download your "DIY Science Time" notebook.

(toy squeaks) You can keep track of all the cool anti-gravity experiments that you try.

Keep notes, share them with your friends and family, and you can go back anytime to see what worked and didn't work.

Pretty awesome, right?

Keep learning, keep exploring, keep having fun, and remember that science is wherever you are.

Let's try this gyroscope once.

(crowd cheering) (dramatic organ chord) See ya!

(gyroscope clicks) Whoa!

(upbeat music) G-R-I- Oops, how do I say?

(laughs) (button beeps) (hands tapping) (mouth whooshing) Gravity!

(laughs) We know that whatever.

That was crazy.

(laughs) It was like, bam!

Goggles.

(button beeps) Oh, I just got glue on the table.

- [Singer] It's science time!

- I read a book on anti-gravity once.

It was so hard to put down.

(laughs) Episode 412 in the books.

Gravity!

Defying gravity.

- [Singer] What's best to see.