You two guys are definitely Phineas and Ferb

5:22 Who the hell screams ”gonnorhea” when they hurt themselves

This never gets old watching it again.

Me after watching this video: “excuse me, friend, can I interest you in this delicious bottle of hot water?”

When they both had different theories I was like oh no it’s like the two smart kids in class getting different answers

Literally every time: Mark Rober: High-Speed Projectiles! Backyard Scientist: Set Everything on Fire!

From a fluid dynamics perspective: It seems to me that hitting the top of the bottle sends a shockwave through the water. Shockwaves have extremely low pressure at the front of the shock and extremely high pressure at the back of the shock. When the front of the wave reaches the bottom of the bottle, that low pressure zone generated by the shockwave induces cavitation (the little pocket of vapor you see at the bottom of the bottle). The water cant hold onto the air bubbles that are already dissolved in it or stay in its liquid phase in this low pressure zone, similar to why boiling water is much easier at the top of a mountain; the atmospheric pressure is less. When the energy of the shockwave dissipates, this vapor bubble (cavitation) collapses...very, very, violently. Often times at supersonic speeds. The force of that vapor bubble collapsing at supersonic speeds (which brings the water crashing down onto the bottom of the bottle), is what breaks the bottle, in my opinion. Perhaps Schlieren imaging could confirm this. It would follow that the CO2 bubbles in carbonation interrupt this shock wave from passing through the liquid, and keep the wave from reaching the bottom with enough energy to induce cavitation. The low pressure zone generated by the shockwave would cause the CO2 bubbles to escape from the liquid, causing the foaming in the beer you see This phenomenon is very similar to the cavitation seen in boat propellers. The propeller spins through the water, generating a low pressure zone behind the blades of the propeller, and when this pressure is low enough, the water can no longer stay in it's liquid phase, releasing any dissolved gas and changing phase to water vapor, generating the vapor bubble you see behind the propeller. When the energy from the propeller dissipates, these vapor bubbles collapse at supersonic speeds, changing the phase back to liquid and dissolving any air/gases back into the water, but at the same time gouging a chunk of metal out of the propeller. Edit: I've edited this post to clarify a few things, thanks to those who commented below!

I learned to do this forty plus years ago, while in college. I always did this the hard way, with coke bottles having thicker glass. Plus seeing why this works would have led to better results.

Rubber mallet is a good idea. I can't tell you how many times I hurt my hand trying this.

I totally think that Mark Rober, Backyard Scientist and the Slow-Mo guys need to make some of these videos together

"So as firm believers of science..." when you hear that

4:03 the moment when you are absolutely, and the absolute joy, these slomo cams brought a new dimension to science

Imagine pulling out some kerosene snowballs during a snowball fight

Funny how he uses a corona bottle for the water

I’ve watched this 3 times and KZfaq just suggested it again so looks like I’m watching it for a 4th. I feel so much smarter and happier after just watching Mark’s videos

I skipped the first part so all I heard was “you should set those on fire” But I only saw the kids so i was like “Set ThE kiDS oN FiRE?”

Tried it at home. Broke all the beer bottles in my fridge. Now dad is beating me. Thank you. *very* much...

Me: It's definitely just air pressure mark: It's not air pressure Me: It's not air pressure

I seriously love these 2 guys! I could watch them all day

Yes! Glad you did this! I, too, thought it was the air pressure forcing the liquid down. I was taught in my teens (in the 80's) by a friend to use wine bottles! No wonder they worked so well being non-carbonated. Thankfully, only about 3 out of 50 have broken in my hand while attempting this.

how to mine glass in minecraft 2:53

3:55 Says they put red colour in The bottle to see The break easier.. shows clip of a bottle with a clear liquid

The fact that they have the "Corona Extra" Beer makes this even better xD

Two things this video impress me is that 1. They came up really easy way to test their theory. 2. The slow-mo technology makes it so easy to prove the second theory. That's such a amazing combination of big brains and technology.

*The Slow-Mo Guys wants to know your location*

5:12 "this is glass" jerryrig : "glass is glass and glass can break"

I love your videos! You do such a good job on them!

We do that with beers at parties. Not to break glasses, but to see people panicking, putting the bottle in their mouth trying to deal with the foam. Quite funny.

"You should set those on fire" Yes throwing fire balls at kids will be fun

*SET IT ON FIRE* -Kevin (The Backyard Scientist) 2016

I really hope the two of you pair up, it will be the best thing that has ever happened

Thank you for bringing me here Steve

2:52 Aww whos a good bottle? Pat pat*

I love it when he shouts in pain Gonorrhea 5:22

Alright ima invite my friends over and give them a beer bottle with hot water it nail polish remover and hit the bottle. What kind of day is that

I’ve been waiting for this video for so long

BEST science channel on KZfaq, I wish he would post more often

5:23 I'm not convinced Mark didn't say "Gonorrhea" in a pained voice

I knew the explanation, but it's interesting to see it tested.

I love it how he explains it so easily

5. Don’t chicken out: Shows mark hitting his hand and then mumbling ‘gonorrhoea!’. Nice

"I'm pretty bored today so I'm gonna smash bottles."

Theory #2 is the physics of a mean practical joke. When someone motions to "clink" your bottles together, instead of "clinking" the necks together, slam your bottle on top of their bottle and watch their beer spill on the floor lol

Congrats On 16 Million !! :)

did he say gonorrhea when he hit his hand on the bottle xD 5:21

I wish he was my science teacher because he would be so fun

The first I heard of this was in college, with Sobe bottles. My coworker bought a Sobe bottle so we could try it out. The story we heard was that you had to keep it sealed for it to work. Hitting it gently, we could hear a loud cracking sound as the vacuum collapsed. Hitting it harder it broke easily. We tried with an opened bottle that was refilled. Cap on or off, it took a harder hit to get the cracking sound. My hand hurt too much to get it to break with the refilled bottle. I would love to see a test rig built to see the impact required for a sealed bottle vs an open bottle vs a refilled bottle with the cap on

Who knew the scientific method could be such fun!

I love how he’s talking about ready player one before the movie came out

I am using this for my science project thanks and I’ll put you as my source of information

Yep. It's the Water-Hammer effect. The water and bottle are pulled together by the vacuum created from the initial strike. The water and bottle come together rapidly, and since water is in not compressible and has high mass, it's like hitting the glass with dense solid object and the glass shatters.

With cap on, it is the vibration of forces exchanging positions like air changing with water force and bottle force with water. Also the bottom of the bottle Is heavier and more dense than the top area. Leads to gravitational pull

He is Obviously the Fun Uncle

0:00 Those trees behind him looked like wings ._.

I love the backyard scientist and mark

ive never had this happen when using a counter top to take off a bottle cap. is it possible that holding it at an angle kinda diffuses the force and causes the bottle not to break.

5:21 did he say “gonorrhea.”

Mark Rober: has a corona beer in his hand *intense breathing*

I've been drinking beer along time. Why did it take 5yrs for this to pop on my feed!

quick way to test the second round of theories would be to pull a vacuum in the bottle and see if it breaks

I’m glad you used Corona bottles😂 fitting for this time

0:28 Nowadays seems like Corona is takin its revenge, ain't it?

Slow motion cameras make experiments such as these soooo much more fun and you can actually get to the bottom of why it happens. Wonder if my iPhone slowmo will also show it? 😂

Very cool trick!!! I tried it myself mind blown!!

Mark literally u are the best you tuber on KZfaq keep up the good work

" just to be more consistent" *also cause I'm a wuss I was dying 😂😂 brush I would too

Your Videos are so interesting, my dad showed me one, a few weeks ago, and now my friend and me are so exited in watching your videos. Ps. Sorry for my englisch😂 I am german

3:30 Without seeing the rest of the video I'd assume it's "water hammer" a.k.a. the volume of rapidly moving water hitting the bottom. And that movement is obviously caused by the vacuum. Similar mechanism is used during water forming to create curved surfaces out of metal for some cars.

0:34 Mark: "...so either Kevin has some superpowers..." Kevin: *nods*

Hypothesis not theory

the shock from your hand travels through the bottle, and meets at the bottom center, as well as the water briefly lifts up(or if there is no liquid, its because of air pressure), and slams back into the glass, both those forces together make the bottle break, easy

Bro just smacked corona

How much beer did you drink during this

05:24 That gave me the greatest nostalgia feeling I've ever had :3 So unexpected I wasn't prepared :o

I love your content.

The beer fizzing up part explains why just slamming the bottom of a beer against a table makes it froth up badly.

On the foaming of beer, I did a research project in chemistry at uni with my professor. And we found that not only do you find that bubbles are made, and then increased because of a chain reaction, but this happens more so in beer than any other drink! And that's because that beer is just crazy good at foaming because the bubbles are more stable, mostly due to the fact that the pH is higher in beer than cider, soft drink, and other carbonated drinks. The more you know!

Oh my god! Ready player one is my favourite book ever!

Great video

What a team!

Kid: *Throws snowball at another kid* The other kid: AAHH IM ON FIREEE Parents: ...

I can barely tell this video is from 2016. You've been incredibly consistent with it.

this duo combined with nile red could probably delete the world

A college friend would always use his wine bottle and cheers people with beer bottles to get them to foam up. I noticed that if the level of carbonated beverage was below the shoulder of the bottle it did not effect it as much. I would love to see some high speed of this difference

I saw this from the slow Mo guys and it creates a vacum

Its a type of a inplosion, and its called cavitation, because of the vacum, steams bubles are formed and when they contract back to liquid they create a hard punch and cause high material tension on a small surface so that causes the glass to brake.

0:53 I’ll drink to that! Not yet you won’t Kevin. *BONK* .... *hahaha*

When he hits the bottle with the mallet, he could be decreasing the volume of the bottle by pushing in the cap, thereby increasing the pressure, no?

that slow mo with the red bottle is so satisfying to hear

You're definitely a nerd, a very cool nerd. I love every video and enjoy your explanations of science. Wishing you well and much success.

Looks like its Kevin that should actually have a big KZfaq channel and following.

Point 3 is wrong, if you have a higher vapour pressure liquid, it will fill more easily the bottom with gas (similar to what happens with the beer). You actually need the opposite, so there is nothing in between the liquid and the bottom when they meet again, this will maximize the impact velocity.

Lol year's later and ready player one Is a movie I didn't even know they had a book 6:00

wow the bottle breaking also removed all of the red food coloring

Wouldn't the liquids with high vapor pressure form more vapor (than liquids with low vapor pressure) at the vacuum and provide the cushioning effect just like carbonated liquids?

We tried this years ago and quickly got bored with busting beer bottles. I had an empty Boone's Farm wine bottle and we all gave it many tries. All of us had bruised hands for a week, but my brother finally knocked the bottom out of it lmao it was spectacular

the *first* bottle they busted was a bottle of *corona* well, we got a lot coming, I can feel it

That book seemed Interesting.. You're actually making me debate if I should get the audible trial or not.. 🤔

maybe is the force of the hit transfer to the structure of the glass, causing a virbration of sort therefore creating an internal stress causing it to break

I don’t know what anything u say means but I love it