-Today, I am here with Kevin more commonly known as the backyard scientist and as fate would have it
-We are actually in
-the backyard
-So I recently made a video where I converted a leaf blower into a snowball machine gun and the first thing
-He said was
-you should set those on fire
-so as soon as I got here today. We
-But flaming snowballs aren't actually why I'm here today show them why I'm here today, Kevin
So I actually don't drink but I've heard of people doing this with beer bottles, so either Kevin has some super powers
Or there's some crazy physics going on there that we're going to try and figure out today
So neither of us really knows what causes these bottles to break and there's a lot of conflicting [evidence] out there
But we have some of our own ideas so as firm believers in the scientific method
We are going [to] science our way to the right answer through a bunch of experiments. I'll drink to that not yet
You won't have it
I've heard that one of the reasons people think it's breaking is because when they slam their hand down [on] it
They're forcing a bunch of air into models and that causes the bottom to shoot out
So in this experiment
We're testing the pressure wave theory where when a person hits it with their hand they force a bunch of air in that then creates
A pressure wave that pushes out the bottom of the bottle so we put a cap on the top
So there's no way to force air in we're using a rubber mallet just to be more consistent for all of the hits
The bottle broke even though the cap was on and there was no way to force air in so we are rejecting this theory
We think carbonation might have something to do with it, okay?
So to isolate that we have one beer that's carbonated one with water, and then we fill this one with sparkling water
[so] if these two [don't] break and this one breaks. I think we've isolated that it works better without carbonation. Yes
So this bottle is filled with sparkling water theory is [that] it shouldn't break
And now for the beer
The bottle didn't break but that was interesting how much it fizzed up. So as it turns out
Here's why [that] happens when you hit the bottle it moves down really fast
[but] the liquid hasn't started moving yet that creates an empty gap down here. That's basically a vacuum or really low pressure
[if] the drink is carbonated the co2 from the liquid gets sucked into that vacuum and fills it with Co2 gas bubbles
Since these bubbles are less dense than the drink they rise up through the liquid and create a chain reaction
Of more bubbles as they go
But finally we test the water and just [like] with the carbonated liquids you [see] this vacuum form on the bottom
Except this time the bottle breaks so theory number two is confirmed
Non-carbonated liquids work better, but now we just have to figure out why what are they doing differently to make the bottle actually break?
so what I think is breaking the bottle is the momentum of the water going back and filling the vacuum is causing the bottom to
break out
And I think the break is happening a little bit earlier when the vacuum is formed like the air outside is at 14
PSI, and so it's in on the back, so it's it's before the water rebounds
It's actually cracking because the difference in pressure. We'll find out. round three fight! So we're going to add some red
Dye and then we're going to slow the camera down to like 7,000 frames per second see precisely
the Moment
So if I'm right, okay bottles it should break right there no
Yeah
Yeah, so you're definitely right it it ruptured when the water is coming back. That's right after it hits the bottom
So Kevin was right in fact it turns out that water cavity
collapses [ten] times faster than it formed which creates a Force higher
Than the [initial] hit on the bottle which is why it doesn't break right away
So now that you know the science if you want to impress your friends with this trick
Here are a couple
Important tips number one hits the bottle and not your hand you want to make as much
energy from your strike go into moving the bottle and not just being reacted by your hand you can even get the neck of the
bottle a little wet and then let it slip a bit when you hit it just to make sure it's moving number two like we
Discovered use water or something
non-carbonated otherwise the carbonation just fills in that vacuum and
Cushions the rebound Force number three a liquid with a high vapor pressure is good if you use a liquid with a high vapor pressure
That means the vacuum you need at the bottom of the bottle will form much easier
So hot water is a lot better than cold [water] because the vapor pressure is higher nail polish remover also works well for the same
reason [number] four be safe
This is glass and glass can cut you if you're not careful where it lands number five don't chicken out
It hurts way [more] if you don't follow through plus. You look like this. [oh], I heard it
So I want to say thanks to audible. I enjoyed recently listening to a book called ready player one
it's set in a dystopian future where people's main escape from the bleak world is to log into a virtual reality world called the
Oasis was created by the richest man on Earth
[but] before he died he hid an easter egg in the Oasis
[and] he promised his entire fortune to the person who could find it, but he warned to be successful
You would need to know a lot about 80s Pop Culture and video games
The story is really creative and intense in fact Steven Spielberg is currently directing the film adaptation
So if you want to listen to ready player one or any book for free all you have to do is use the link in
The description or go to audible.com/MarkRober
Thanks for watching