Testing If You Can Blow Your Own Sail
Summary
TLDRThe video explores various physics and engineering puzzles, starting with a test of whether a fan blowing on a sail can move a boat. It continues with a journey to the equator to debunk the myth of water draining in opposite directions due to the Coriolis effect. Other phenomena investigated include the appearance of the moon from different hemispheres, the elliptical room in the US Capitol with exceptional acoustics, the effect of air mass on the movement of objects in a car, and the principles behind sailboats and fan-powered boats. The video also discusses the concept of a floating backpack and the intriguing fact that only a small amount of extra rope is needed to raise a rope around any size circle by one foot. The presenter's goal is to not only inform but also to inspire understanding and curiosity about the physics behind everyday phenomena.
Takeaways
- 🚤 Testing if a fan blowing on a sail can move a boat forward.
- 🌍 Traveling to the equator to investigate the Coriolis effect and its impact on water drainage and toilet flush directions.
- 🌙 The moon appears upside down in the Northern and Southern Hemispheres due to the perspective from Earth's poles.
- 🔴 The focus points of an ellipse have unique properties where a line from one focus to any point on the ellipse will bounce off and hit the other focus.
- 🚗 The reason why the cake slides forward and balloons move backward in a car when brakes are applied is due to Newton's laws of motion and the behavior of air mass.
- 🎈 Air molecules have mass and can exert force, demonstrated by the effect of inflating a balloon and its impact on a sign.
- 🛳️ Sailboats move by harnessing wind power, and a fan can theoretically move a boat if positioned correctly, similar to a propeller.
- 🛴 Debunking the viral video of an umbrella and leaf blower setup on a skateboard, showing it's actually the electric skateboard's battery that powers movement.
- 🌐 The extra length of rope needed to raise a loop around the Earth by one foot is 6.28 feet, regardless of the Earth's size.
- 🎒 The Hoverglide backpack claims to reduce impact forces by 86%, but its effectiveness is debated and depends on the terrain.
- 🌀 The Coriolis effect is responsible for the rotation direction of weather patterns like hurricanes and cyclones, but its effect on water drainage in sinks and toilets is negligible.
Q & A
What is the purpose of the fan experiment mentioned in the script?
-The purpose of the fan experiment is to test whether blowing air on a sail can move a boat forward, similar to how wind propels a sailboat.
What does the traveler plan to investigate at the equator?
-The traveler plans to investigate if the demonstration that water drains in opposite directions on either side of the equator is a scam, as well as the claim that toilets flush in opposite directions in different hemispheres.
How does the moon's appearance differ between the Northern and Southern Hemispheres?
-The moon appears upside down when viewed from the Southern Hemisphere compared to the Northern Hemisphere due to the perspective from opposite sides of the Earth.
What is the significance of the focus points in an ellipse?
-The focus points in an ellipse are special because any straight line shot from one focus point will bounce off the ellipse's wall and hit the other focus point, making them important in physics and geometry.
How does Newton's first law relate to the cake sliding forward in a car?
-Newton's first law, also known as the law of inertia, states that an object at rest stays at rest unless acted upon by an external force. The cake slides forward because it tends to stay still, and the car's sudden stop is the external force that moves it.
What causes the air to push the balloon backwards when the car brakes?
-The air has mass and acts as a fluid. When the car brakes, the air inside the car continues moving forward due to inertia, creating a pressure difference that pushes the lighter balloon backwards.
Why doesn't the fan attached to the boat move it forward in the experiment?
-The fan doesn't move the boat forward because the sail is designed to catch wind, not to propel against the denser water like a propeller would. The fan would be more effective if placed underwater like a propeller.
What is the Coriolis effect and how does it influence weather patterns?
-The Coriolis effect is an apparent force that causes moving objects to be deflected to one side due to the Earth's rotation. It causes weather patterns like hurricanes to spin counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Why does the water in the tourist demonstration appear to drain in opposite directions on either side of the equator?
-The water appears to drain in opposite directions due to subtle twisting motions made by the person pouring the water, which continues the swirl in the direction of the twist, not because of the Coriolis effect as is commonly believed.
What is CrunchLabs and how does it relate to the content of the script?
-CrunchLabs is a subscription service that sends a fun toy with a video explanation of the physics and engineering principles behind it every month. It is related to the script as it aims to provide educational content in an entertaining way, similar to the experiments and demonstrations discussed in the video.
Outlines
🚣♂️ Sailing with a Fan and Equatorial Experiments
The video begins with an experiment to see if a fan blowing on a sail can move a boat forward. The host then travels to the equator to test the popular tourist demonstration that water drains in opposite directions depending on whether you're in the northern or southern hemisphere. The video aims to debunk myths and uncover the truth behind these phenomena, as well as explore other physics and engineering puzzles. The host also introduces the concept of how the moon's appearance differs between hemispheres and why this is the case.
🎈 The Physics of Balloons and Air Mass
This paragraph delves into the physics behind why a helium balloon moves backwards when the car brakes suddenly. It explains the concept of air having mass and how it behaves like a fluid, affecting the motion of objects. The host uses the example of a balloon's interaction with a sign to demonstrate how adding air (mass) to the balloon changes the outcome of the collision. The discussion then transitions to the behavior of objects in a car when the brakes are applied, and how the air inside the car contributes to the motion of the objects.
🛳️ Boat Propulsion and the Myth of the Electric Skateboard
The host explores the idea of using a fan to power a boat, comparing it to a viral video of someone using a leaf blower on an umbrella to move on a skateboard. Through a series of demonstrations, it is revealed that the fan does indeed move the boat, but the setup is inefficient and not practical. The video also debunks the skateboard myth by showing that the movement is due to an electric skateboard, not the leaf blower or umbrella. The host then discusses the principles of boat propulsion, including the use of sails and propellers.
🎒 The Floating Backpack and the Coriolis Effect
The video examines a Kickstarter product, the hoverglide backpack, which claims to reduce impact forces by 80-90%. The host provides a balanced view of the product's potential benefits and drawbacks, concluding that it may be useful on flat terrain but not on rough hiking trails. The discussion then shifts to the Coriolis effect, explaining its impact on weather patterns and its supposed influence on the direction of water drainage. The host debunks the myth that sinks and toilets drain in opposite directions across the hemispheres, attributing the observed effects to other factors.
🌍 Debunking Equatorial Myths and the Power of Learning
The host concludes the video by debunking the tourist demonstration that claims water drains in opposite directions at the equator. Through careful observation and a simple at-home experiment, it is shown that the demonstration is a trick. The host emphasizes the importance of a passion for learning and introduces CrunchLabs, a subscription service that delivers a fun toy with educational content each month, designed to inspire interest in STEM and engineering among children.
Mindmap
Keywords
💡Equator
💡Coriolis Effect
💡Newton's Laws of Motion
💡Ellipse
💡Air Pressure
💡Fluid Dynamics
💡Physics
💡Engineering
💡Phenomena
💡Demos and Experiments
💡STEM
Highlights
Testing if a fan blowing on a sail can move a boat forward.
Journey to the equator to investigate the tourist demo of water draining in opposite directions.
Exploring the phenomenon of the moon appearing upside down in different hemispheres.
Demonstration of the ellipse's focus points and their properties using a laser pointer and wax.
Investigating why balloons move backwards when a car brakes suddenly.
Experiment with a fan attached to a train car to understand the principles of propulsion.
Explaining the ineffectiveness of using a fan to propel a boat without a sail.
Debunking the myth of toilets flushing in opposite directions in different hemispheres.
The Coriolis effect's role in the perceived direction of water drainage at the equator.
Exposing the tourist demo as a scam with a subtle pouring technique.
The real magic of the video: transferring knowledge from the creator's brain to the viewer's.
Introducing CrunchLabs, a monthly subscription service for learning physics and engineering through toys.
CrunchLabs' aim to make learning fun and engaging for children.
The opportunity to win a platinum ticket to build with the CrunchLabs team.
Investing in the passion for learning through CrunchLabs.
The effectiveness of CrunchLabs in sparking a new passion for STEM among children.
The importance of understanding the physics behind everyday phenomena.
The role of air pressure and mass in the movement of objects in a car.
The concept of Newton's first and second laws of motion in everyday scenarios.
Transcripts
I'm about to plug in this fan to test whether blowing on this sail
will move the boat forward.
And then I'm traveling 4000 miles to the equator
where I'm actually standing in both the northern and southern hemispheres,
because this line here is the equator, and I'm here to investigate
whether or not this demo for tourists is a scam.
Basically, they pour water in this basin and on the north side of the equator,
it seems to swirl and drain counterclockwise,
but just a few feet away in the southern hemisphere.
The water seems to drain in the exact opposite direction.
It's sort of like how you also might have heard
toilets flush in opposite directions on different sides of the equator.
And we're here to uncover the truth.
But I'm not stopping there because today we're going to investigate
six other physics and engineering puzzles using simple demonstrations as we go.
Because our goal by the end of this video is for you
not just to know the right answers, but more importantly
for you to understand and why they're the right answers.
To kick things off.
Speaking of Hemispheres
did you know the moon in the sky
looks like this in the Northern hemisphere, like in Canada.
But it looks like this in the southern hemisphere, like in Australia.
It's upside down!
And while that is a fun fact, it's even more fun to understand why.
And this is why
As we all know, the Earth is...
a sphere.
So if you were Superman standing at the North Pole
in the Northern hemisphere, you'd look like this.
But if you were
Thor standing in the southern hemisphere in Antarctica, you'd look like this.
Now, of course, the moon over here orbits around the earth
like this, and I'm going to add an arrow to it to help us with orientation.
And so to the Superman at the North Pole
That arrow would point up, but from the perspective of Thor at the South Pole
That arrow would point down from his perspective.
And now I know what you're thinking.
If all that's true, then which way would the arrow point?
If you're Spiderman, standing here at the equator.
Well, according to our model here, it should be sideways
and sure enough, here in Ecuador, at the equator.
I'm happy to report that the moon does, in fact, appear to be sideways
For fun fact two of seven.
If you just stick
two pins into some cardboard like this and then connect them with a string
and trace it out, you get my favorite geometric shape...
an ellipse!
But there's something really special about these two pinholes.
They're called the focus points.
And any straight line you shoot out in any direction from one of the points
will bounce off the wall of the Ellipse and always hit the other focus point.
And here's proof because I've got a laser pointer
at one focused point, a ball of wax at the other,
and a mirrored surface all along the interior wall.
And now you can see, no matter which way I point the laser,
it always bounces off and lights up the wax.
But here's the really cool part.
If you build an actual full sized room
in the shape of an ellipse and then you stand at one focus point,
you can hear even the faintest whisper from anyone
standing at the other focus point, even hundreds of feet away,
because all the sound waves bounce right back to your ears
in fact,
this actual ellipse shaped room was built by John Quincy Adams
in the US Capitol building.
And legend has it, he was a master at anticipating the moves
of his opponents, plotting against him on the opposite side of the large hall.
And now that you know the physics involved,
it should come as no surprise that John Quincy Adams
conveniently placed his desk right on top of this leftmost focus point.
Next up at number three,
everyone knows when you slam
on the accelerator pedal in a car, the stuff in slides backwards.
And then when you slam on the brakes, the stuff inside just keeps moving
forward, including you, by the way
which is why we were seatbelts.
So then why the heck when I'm driving to the birthday party
and I have to slam on the brakes
does the cake slide forward?
But the balloons actually move backwards?
Now as for the cake sliding forward
Well, that's just Newton's first law in action,
which basically says all stuff is kind of lazy and wants to stay still
unless a force comes in and tries to move things.
And then Newton's second law tells us that the more you weigh
and the more mass you have, the more force is required to even get you to move.
But here's the thing we sometimes forget.
The air around us is a fluid and it also has mass.
It weighs something.
This is why air pressure is a thing.
There's tons of air molecules
stacked up above us and they each weigh just a tiny bit.
So we are like at the bottom of this air molecule dogpile.
This is why your chip bag expands when you head up to the mountains.
It's because it's moved up the dogpile.
Now there's less air above it, weighing down, pushing in on all sides.
And for a little proof, here's a simple demonstration
that the air molecules around us do actually weigh something.
When I throw this balloon at the sign, it moves,
but it doesn't quite knock it over.
Now, all I'm going to do is take that exact same balloon and just add air.
That's it.
Everything else is identical and unchanged.
And yet now, it bonks the sign over.
So that means we increased the mass only by adding some extra air.
Because again, Newton's
second law states
the heavier, the more massive a thing is
the better it is at bonking things over.
So in the car, when you slam on the brakes
it’s not just the stuff in the back that has mass that wants to keep moving,
but all that invisible air does too.
So the air itself also sloshes forward when I slam on the brakes.
And since that air is more dense than the helium gas in the balloon,
the lightweight balloon gets forced backwards.
And that's what we'd expect, right?
We say a helium balloon floats in air
or this ping pong ball floats in water
but it's almost more like the heavier, more dense thing
in this case, the water
rudely cuts to the front of the line
forcing the poor ping pong ball up and out of the way.
In fact, you can see if we lay this jar on its side.
The same thing happens as in the car.
When I give the jar a push,
the water sloshes back, which forces the ping pong ball forward
and then when it stops
the water sloshes forward, forcing the ping pong ball back
then for number four, we're back here on the lake
to figure out if sailboats move by having wind blow in their sails
Why don't they just get a big old fan like this
to power them through the water?
Sort of like the guy in this viral video who's using a leaf blower
pointing into an umbrella to scoot his way around on a skateboard.
Well, let's think this through with the simple demo of a fan
that's attached to this train car.
When I turn the fan on
and it blows air to the right, which way will the car go?
Well, of course it goes to the left because it's basically
cutting through the air and pushing it backwards,
which creates an equal and opposite reaction that pushes the train forward.
Just like an airplane propeller pushing air backwards, moves the plane forward.
It's so different than me standing on this skateboard
And when I push watermelons to the left, they push back on me
So I roll to the right
NATE! AGAIN!?
And so now let's place a brick here so this car can't move.
And then add a second car here with a sail.
Now, when I turn the fan on, which way will this cart move?
Of course, to the right.
Because all that fast moving air hits the sail.
It's like it's being bonked by all those tiny little watermelons.
So if we now remove the brick and this cart wants to move to the left,
and then this one wants to move to the right,
what'll happen when we connect them?
Nothing,
because it's a perfectly timed tug of war with each car
trying to move in opposite directions with the same amount of force.
A fan actually sort of does work to move a boat forward,
you just have to lose the sail and point it the other way.
But at that point you might as well
just take that same fan and stick it underneath the boat
so you could much more effectively push
against the heavy water instead of just air,
which is, of course, exactly what a boat propeller does.
And sure enough, when I plug it in, in real life
as you can see,
I don't go anywhere.
So then if we've totally debunked the idea of blowing your own sail,
then what about that guy with the leaf blower and umbrella on the skateboard?
Well, I've copied his exact same setup here, and I can confirm it
actually does work.
Yeee Hooo!
Yeee Haaa!
It just has nothing to do with the umbrella
or the leaf blower
and everything to do with the fact that this is an electric skateboard
with the battery stored right under here.
Exactly the same as you can see in a bunch of these shots from his video.
Now, before we get to the last three, including answering
if this demo for tourists is a scam, if you're like me and you love that
ah-ha moment when you learn something new
well, I got great news for you.
Let me guess. CrunchLabs?
I'm glad you said it, Jimmy. That's right.
Because packaging up that movement is why I created CrunchLabs,
where you get a super fun toy every month in the mail
that comes with a video
where I teach you all the juicy physics that make the toy work.
Mark won't say this himself,
but obviously he used to work at NASA and Apple.
He's one of the greatest engineers that you can ever find,
and he's specifically designing these boxes
teach you all the stuff he learned
He had this water gun that we made.
And you can flip a switch when you give it to someone else
and it shoots back at you.
I mean, that's awesome.
I've pranked you a couple times with the boxes, Jimmy.
I know.
So if you want to prank MrBeast
while experiencing
a bunch of those lovely ah-ha moments at the same time
It worked!
just visit crunchlabs.com
to learn more.
Yesss!
Now coming in at number five is the craziest fact I know
Imagine I just finished tying this rope all the way around the world,
but now I just found out
it was supposed to be a foot off the ground the whole way around.
So the question is how much more extra rope would I need to buy to add
to this rope to make that happen.
Now, you might be thinking double or even triple this amount, but
what if I told you you only need this much extra rope
6.28 feet to be exact.
Think about that.
The circumference of the earth is 131 million feet.
And yet you only need this much extra rope to lift the whole thing
a foot off the ground all the way around.
And what's even crazier is if you did this around a basketball,
it would be the exact same amount of extra rope.
Now the math is just some straightforward eighth grade algebra.
And you can see here
because the radius cancels out, it doesn't matter what size circle
you use, it always works out to two pi or about 6.28 feet of extra rope.
But if math isn't your thing, don't worry,
because if you just pretend the earth is a square,
it will immediately be obvious why the size of the object doesn't matter.
So if this is my initial rope
When I raise it off the earth
by one foot, you can see in each corner I only need two extra feet.
So eight feet total.
And just like with the basketball, you’d still get the same answer
If you try it on a smaller four-sided shape like your TV,
which is pretty close to the 6.28 extra feet needed for a circle.
At number six, there was a Kickstarter a while back.
that claimed to have invented a floating backpack that reduced
impact forces by 86%.
Welcome to the Future of backpacking.
You've never seen a backpack that moves like this
or that lets you move like this.
And this motion isn't just for show.
By suspending the load, hoverglide reduces impact forces by 80 to 90%.
I really took an interest once I noticed
a lot of people in the comment section
were debating whether or not this would actually help.
So what do you think?
Is this a scam?
The case for it not being a scam is that when you wear a normal backpack
as you bounce up and down
with each step you take
you're working against gravity as you move that entire weight
up and down with you as well.
Sort of like pulling this weight up and down with a stiff rope.
But if the backpack was elastically suspended on a track, its own
inertia would tend to keep it vertically in the same spot.
So you can still bounce up and down while the pack wouldn't move
so it’d be like replacing that stiff rope
with an elastic one at which point you can see it makes it a lot
easier on my arms moving up and down as the weight stays in place.
But the naysayers pointed out
all the pulleys, cords and extra frames to make the system work
is still an extra 4 pounds of weight.
And whether it's bouncing or not, you're still carrying four extra pounds
to the top of the mountain.
Plus, the video just shows the ideal use cases, and in real life
it probably wouldn't work that smoothly, hiking over rough terrain.
And I felt like both sides sort of had valid arguments.
So as a firm believer in the scientific method, I ordered one myself.
And then went hiking for a few miles
with a normal backpack and then put the exact same amount of
weight in the hover glide backpack to qualitatively compare the difference.
So far, I don't like it. Feels like it's, like, rocking me back.
I’m going to try jogging.
oh that feels good.
That's kind of the trick I feel like
if you hit the right cadence, it's magical.
if it's not the right cadence,
It's the opposite of magic. oh yeah. Now it's.
And then it gets out of sync, throws you literally off balance
So my verdict is that on flat, predictable terrain,
it can be beneficial.
But on any sort of rough, sporadic hiking terrain, it's just not worth
the extra weight in force from out of sync issues.
And for our final science challenge, we're back here at the equator
in Ecuador to see if this popular demonstration for tourists
is actually a scam.
Does the water really drain in opposite directions,
even just a few feet on either side of the equator?
And relatedly, do toilets also swirl in opposite directions
in the northern versus southern hemisphere.
Now, for the toilets, let me just debunk that myth out of the gate,
because if you look closely, the swirl direction is just
a function of which way the nozzles point, as you could see here.
And with any toilet you inspect yourself.
But what about sinks that have just a drain
like in the demo here where there are no nozzles?
Well, believe it or not, there's actually some truth to this idea
because of something called the Coriolis effect.
And it's the same reason you might have noticed weather patterns
like this spinning counterclockwise in the northern hemisphere,
in which case we call them hurricanes and clockwise
in the southern hemisphere, in which case we call them cyclones.
And the reason for this is pretty straightforward to understand
If you imagine you have a very big sink that spans from the equator
all the way up to the North Pole, In that case,
a single drop of water in the sink at
the equator here is going for a joyride really fast as the earth spins
and a drop of water near the middle is moving at a medium speed.
But a drop of water at the North Pole
isn't moving at all because it's right on the axis.
So now when you pull the plug on the sink
and the water moves towards the middle, the joyriding drop here is suddenly
moving faster than the slower water that was away from the equator.
So it gets out in front of the drain
and conversely, the drop at the North Pole
is now moving much slower than the water closer to the equator.
So it falls behind.
So when all the drops are affected this way
you naturally get a counterclockwise swirl just like a hurricane
where the eye of the hurricane is the low pressure zone like a drain.
Then of course, applying all this same logic to the southern hemisphere
would of course do the opposite, resulting in a clockwise swirl.
So does this mean that sinks do in fact drain
opposite in the northern and southern hemispheres?
Well, sadly, no, because the Coriolis effect is really only noticeable
The greater distance you're moving up or down from the equator.
So unless you have a five mile wide sink, or if you make the most perfect
of perfect conditions, like my friends Destin and Derrick showed,
The water is flowing clockwise due to the earth’s rotation
The water is going counter clockwise because I’m in the northern hemisphere
It’s real!
this effect is way too small to have any meaningful impact
on the swirl directions of sinks and toilets,
at which point
it comes down to other factors like sink geometry
or the fact that the seemingly still water
was actually still barely moving around when the plug was pulled.
So then what about that tourist demo? Well,
if you play it back and look closely, you can see the end of his pour.
He does this subtle twisting motion so the water would just continue
to swirl in the direction of the twist.
So when he finishes the pour here,
he twists this way and the water continues swirling that way.
And then after moving the sink, allegedly over the equator,
he finishes his pour, twisting the opposite direction,
and then the water swirls in that opposite direction.
In fact, you can easily recreate this demo yourself at home
to see that by copying this method,
you can also easily get a whirlpool in both directions
and therefore it should come as no surprise that when I ask this question
does it work even like if I pour the water,
I was denied the opportunity to test and observe
on top of all that as the final nail in the coffin
If you actually look up the GPS coordinates of this place,
it’s more than a football field away from the official equator,
which means we were actually in the southern hemisphere the whole time.
So instead of actual science, this is just an attempt
to take your money with nothing more than a lame magic trick
where the real magic is all that new juicy knowledge
I just wirelessly transfered through that screen you’re watching me on
from my brain into yours.
It's a new year, which means it's a great time
to invest in that passion for learning, because that passion is not
only the main driver for why I make these YouTube videos,
but it's also why I created CrunchLabs
where we ship a really fun toy to your porch every month.
And not only do you learn how to build and think like an engineer,
but you learn the fascinating physics and engineering principles
that make the toys work.
Every month is a new principle, and the best part is just like
how you hopefully enjoyed watching this video.
It doesn't feel like learning because we're real good
at hiding the vegetables.
And what I mean by that is 87% of kids rate it an eight through ten
on a fun scale out of ten.
But also more than three out of four parents said their child
gained a new passion around STEM and engineering after getting the build box.
Yessss
On top of that, each month, your box
has a chance to contain the platinum ticket and if you get it,
Well then you coming out to CrunchLabs to build with me and my team for a day.
So if you want to invest in the superpower
of having a passion for learning, just go to CrunchLabs.com or use
the link in the video description to get your build box subscription today.
Thanks for watching.
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