How fast does glass crack? - The Slow Mo Guys

[@theslowmoguys]

Hello everyone. I recommend you watch this one full screen or on a computer so you can see the cracks more clearly. They look bloody tiny on a phone screen! - Gav

[@GermaphobeMusic]

You can't tell me what to do!

[@littleike2228]

Don’t tell me what to do

[@mdmahmudulhasanmilu3159]

*Hello The Slow Mo Guys✔*

[@DMadHacks]

oh woawie

[@NoahPurdyFR]

It worked fine on my phone idkw

[@perschistence2651]

So if the earth was made of glass, it would take roundabout four hours till it is completely shattered into pieces.

[@jablinskisgoat9504]

Thank you Michael very cool👌

[@drBVR]

2.4h if you would crack it at the surface! The crack goes THROUGH the sphere, not only by the surface!

[@perschistence2651]

@@drBVR That would be true, if the earth wouln't be hollow like a Christmas tree ball.

[@drBVR]

@@perschistence2651 Ah.. yes.. I had to google it, but you are right.. the earth is hollow! At least Donald thinks so, so it must be right!?

[@perschistence2651]

@@drBVR Exactly, you see, the internet knows everything!

[@theCodyReeder]

Glass should break at the speed of sound through glass. You can look up the speed of sound in glass and find values between 4 to 5 km/second. So why does the glass seem to break at 1/3rd that speed? Well after thinking it over I realized that just like seismic waves during an earthquake there are different types of waves traveling at different speeds! So which sound wave are we observing? The "P" or "primary compression wave" travels fastest at about 4-5km/s in rock like material (glass) and is what is generally used for "speed of sound" but that of course travels far faster than what we see here. The "S" or "secondary shear wave" has a typical speed around 60% of that of P-waves in any given material. Great! but this means the "S" wave velocity is still too fast and cant be the culprit. So that leaves the 3rd type of seismic wave: "surface" or "Rayleigh waves". Rayleigh are a lot like the "wave" produced by taking a tight string and flicking it; making the string tighter makes the wave travel faster. Unfortunately this means that "Rayleigh velocity for a sheet of tempered glass" is not something I can easially look up so I will have to approximate using the equation: v=sqrt((N/m^2)/((kg/m^3)/m) We know that surface of tempered glass has 10,000 psi (~7000N/cm^2) of compression ( leaving the inside under tension). We also know that the density of glass is 2.5g/cm^3. Plugging this into and simplifying the equation I am left with: sqrt(7000N/.0025kg) = 1700m/s which is close to the velocity observed! Now this makes sense since the stress that ultimately caused the glass to break was similar to "flicking" the end of a tight rope. I predict that if you hit the edge of the glass with a hammer (or maybe bullet) so that the "p" wave is causing the glass to fail we should observe a much faster (4.5Km/s) glass breaking velocity.

[@SidewinderScience]

Wow! I think this might be the longest comment you've made in a while.

[@vacuumtube8933]

Ah. much better explained than the first comment you made.

[@theCodyReeder]

@@khubba10 Well It is a good way to push the comment up to the top.

[@devenirpyro]

@@theCodyReeder true story, amazing explanation

[@Keith_Rothwell]

Cody'sLab Look at mister smart guy here! :p

[@20poundvoucher]

Love the analysis in this video. Dans description of the curvature of the fractures by considering the pane as a section of larger circle is spot on. Not only is it mathematically/physically correct they, explain it in such a way most people can understand it

[@7f0g20]

Hello im responding fast!

[@theslowmoguys]

GaeafBlaidde was a good example of us being able to immediately learn from the footage we took. Love it when that happens. - Gav

[@HakanBacon]

Yeah you're right. It's such a complicated process put in this less than a second video. It's just awsome!

[@oswaldovzki]

indeed!

[@Cytrillex]

yeah that was really genius. They're two pretty smart blokes considering some of the ridiculous things they do on this channel

[@ilian9420]

2:44 that flash of light was everything

[@yKuroKenshi]

You talk like a girl

[@crypticgaming3849]

@@yKuroKenshi stfu, you legit like rainbows

[@yKuroKenshi]

@@crypticgaming3849 wtf of course I like rainbows... Wdym????

[@pcd9230]

@@yKuroKenshi kzbin.info/www/bejne/fp-9ZaaFeLpkkLs

[@manmannihan5403]

@@crypticgaming3849 what’s wrong with rainbows mate

[@bingewatch8002]

I don't think shorts were the best clothing option for shattering glass at extremely close range.

[@DinnerForkTongue]

It's safety glass. Very unlikely to cut anything.

[@jenniferlynn3579]

@@DinnerForkTongue I can confirm that tempered "safety" glass is indeed much safer and less likely to cut, but it is still glass and can still cut if you're right next to it when it shatters. I came here to this video to see what is happening in slow-mo since two hours ago I suffered multiple lacerations from a dusty arcade cabinet glass panel that slipped through my fingers and shattered right next to my exposed, shorts-wearing legs. It was like a miniature grenade going off and blasting tiny shards of glass into me. Much smaller than the glass nuggets that made up the majority of the debris. Some of the cuts were fairly deep, as well. Not enough to need stitches, but yikes. Two of the cuts took tiny chunks out of me. Definitely would not recommend breaking any form of glass next to your bare legs.

[@MothloolVA]

@@jenniferlynn3579 Wtf is that XD just write a whole book

[@bupi9372]

@@jenniferlynn3579 omgsh that's insane!! Are you better now? 🌻 It must have taken ages to get all the glass out (?) :0

[@yungcuben4137]

Glass can cut though pants

[@fluffyou9276]

At 6:00 they debunked the "where's the curve" argument of flat earthers.

[@heyhuhh1366]

But Flat earthers still wont believe it. Science arguments for flat eathers is like garlic for a vampire

[@AriGoldFishing9136]

globe companies say the earth is round to sell more globes science confirmed

[@heyhuhh1366]

@@AriGoldFishing9136 Ah I forgot about billion making globe industry right after NRA and oil

[@e_c_t]

Fluff you one thousandth like

[@stevengleave9241]

Wheres your evidence?

[@silent596]

To this day it still takes me a minute to remember that Dan is holding the glass in the beginning.

[@muserweaver]

And wears shorts

[@smartereveryday]

Excellent analysis on the failure front.

[@oscartigwell]

I'd love to see you do more glass cracking, Destin! Possible collaboration with Gav & Dan? :D

[@WeArePharmers]

Hi Destin! I was going to say, this video reminded me a lot of your Prince Rupert's drop video!

[@remi460]

Hi Destin

[@coreymeh8335]

We expect a video now with your detailed analysis ;)

[@luispuma25]

I think you are the right person to answer this question, is the speed that they calculated the speed of acoustic waves (namely the "speed of sound") through that specific material?

[@itisinfactpaul2868]

The speed measured here is actually the speed of sound in glass!

[@aleksey4e]

Yes, and it's very sad that authors didn't mention that. In fact it's common property of solid substances

[@gryffindorgirl1009]

WOA

[@emilio_448]

A question, should i calculate Mach with the speed of sound in the glass or the speed of sound in the air at room temperature?

[@itisinfactpaul2868]

@@emilio_448 You only use 'Mach' when you're talking about an object moving through a fluid, and since contrary to popular belief, glass is *NOT* a liquid, I assume you would want to calculate the speed of sound in the air. What exactly are you trying to do?

[@Othmar98]

That is wrong. The speed of sound in glass is between 4000 and 5000 m/s instead of the 1458 m/s that they measured.

[@filip8689]

Dan: cracks tons of glass Also Dan: wears shorts

[@Reblwitoutacause]

Milenium lets all be honest with ourselves here.... we’re all just so proud of him that it’s not crocs with socks ( yet )

[@digiorno5600]

Short pants.

[@uly_flexpoint1120]

Its called shorts

[@iP0STcomments]

shants

[@Vleaso]

@@iP0STcomments ports

[@drowsiestvirus484]

Dan just accidently explained how the earth is round

[@orangegradient4309]

Haha

[@antknee420]

? There is no factual repeatable proof of it being round, so what did he say?

[@_itsjustcat]

antknee420 at 6:05. make what you will of what he says. Personally, I think the earth is round but if you think the earth is flat, ok. As long as you’re not hurting anyone, do and think whatever you want.

[@drowsiestvirus484]

@@antknee420 it response for just Catie finding the part, the line is like the horizon

[@qwe.2739]

face it the earth is a banana

[@spaghetti4896]

8:08 I think it’s so cool that after all these years they are still mesmerized by what their cameras can do

[@jonanderson5137]

Sponsorship is a helluva drug.

[@PrabhuRPR]

yup

[@dunno6442]

@@timmoe3370 no Edit: whoops I made him delete his link 😂😂

[@sofakingonmynuts1438]

Gavin spent a good amount of money and i see why, being able to crop the image and get a better frames per second, very versatile camera. He has done it in other videos, or with another camera.

[@zimmermanjohn3797]

I think it’s partly because as they have been uploading for so long so technology has advanced so the cameras are much better so even for them they keep being really impressive.

[@eeliasish]

i cant be the only who didn’t notice the glass plane at the beginning of the video.

[@mishkadoll25]

I thought it was so weird Dan had his hand out like that until he moved the glass. 🤭

[@all-mightyloaf3192]

I thought it was my phone that had cracked at first

[@tylerquigley7687]

It surprised me

[@Prophet_waffle]

Jose Ramirez that got me too

[@littleyellowbus4862]

Nope, your not alone 😂

[@MrHesdan]

Really cool to see phineas & ferb still doing cool stuff in the backyard after all these years.

[@Tremor244]

hahaha, good one

[@beerenmusli8220]

LoL^^

[@sajidahmed9732]

0:59 when the tea and crumpets is on point

[@Lickwetcarrion]

Might be one of the nicest videos, visually, ever made on KZbin. The edits, cuts, little moments... Brilliant video.

[@scatered1]

Hahaha I like how you are talking about this video as if it's anything more than just a couple of chaps breaking glass to see what it looks like in slow motion and lazily trying to explain the science behind it all

[@danielkuf2593]

And not even 10 minutes.

[@SovietMemes]

Thank you John, very cool!

[@guyfriedman295]

Lol welcome to the SloMo Guys...

[@Lickwetcarrion]

@@scatered1 Yet they still did an excellent job, and it got over four million, very well deserved, views. That is their magic, my friend.

[@PressTube]

You should try to fire a bullet at the same time and then compare the speed of the bullet with the speed of the breaking glass ;)

[@Wissmann80]

Do this. Please!

[@awppenheimer]

It would probably be too difficult to coordinate

[@evanredacted7977]

Glass would far outpace the bullet. Bullets don't travel at Mach 4.2

[@michaelitsyaboymb8300]

Most bullets would look slow compared to this speed

[@borginator1493]

@@michaelitsyaboymb8300 Got that right!

[@liminal548]

4:34 companies 0.001 seconds after pride month ends

[@9hundredone415]

FadeFA I was just about to comment that

[@montpc259]

It's a shame pride month exists at all.

[@necronomics1804]

@@montpc259 could you elaborate a bit more on that

[@swampyswamperton6536]

@@necronomics1804 I think it's because companies don't really care. They just celebrate pride month to seem inclusive.

[@alexn9198]

Mont PC preach brother

[@josephyap3198]

A road of glass would finish "cracking" from New York to London in 1 hours and 2 minutes

[@mranonymous481]

Did you calculated that yourself?

[@mranonymous481]

I figured it out and it would break from London to Los Angeles in 1.8 hours.

[@FreakingPlane]

Wow thats mad

[@nnewt8445]

Dang... I could watch one act of a Gilbert & Sullivan opera in the time it takes for that road of glass to crack, lol.

[@PunchCounterpunch_Lizzy]

I’d love to see that

[@daylenkyles626]

The only KZbinrs I can’t get mad at for taking forever to upload.

[@teamcyeborg]

They're uploading in slow motion.

[@dashiefiles]

Because it’s quality

[@itsafkinjamina9377]

Domics?

[@aaronjou2220]

What about vsauce

[@ashdamm9007]

That intro was beautiful. I noticed Dan holding it but didn’t realize it was glass!

[@triforce228]

I thought my phone screen was cracked because I dropped it like 15 minutes ago. It actually scared me for 5 second

[@AxxLAfriku]

the intro is beautiful but so are my two girlfriends

[@mynameistaken99]

I didn't notice at all! Tricky 😆

[@PP-bs3od]

"I'm gonna bung in a ton of shutter here. 45 degrees?" - "Ooh, that's naughty! You never do that" "Bloody naughty innit." Love these guys.

[@xenorama7033]

I didn't/don't know what any of that means, but "bung" makes me chuckle a little.

[@1earflapping]

"I think it's time to get carried away." The basic principle of this channel.

[@GippyHappy]

I love that this channel made me actually enjoy learning and it’s just 2 dudes painting rainbows on things and breaking them (for science)

[@charredtodeath2205]

The different between science and messing around is writing (or recording) it down xD

[@Rachel-fi4sc]

I love that quote.

[@peten42]

me: "Should i google what that number is in meters?... nah.." Gav: "And for the International audience" me again: "nice."

[@zombievac]

General rule: 1 meter = 3.3 feet (so I just multiply by 3 in my head, and then add a bit for the remainder if I don't need exact figures)

[@pocketlint82]

Marking it in feet like a proper American. Gav is fully indoctrinated now.

[@cykachu8080]

pocketlint82 marking in feet like a proper inferior system user

[@dwobneb]

@@pocketlint82 lol we use feet for a lot of things in the UK too measuring the height of a person for example

[@TheMharr]

@@zombievac Why not multiply by 10 then divide by three? No guesswork then!

[@skimtvns8486]

Watching this on my cracked phone

[@adriancarreira243]

Savage

[@strema7750]

Wow, your screen refresh rate might be on mach 4.2 😂

[@ella-maisharp1679]

Same 😂

[@paul7787]

Do you know how fast was that cracked?...🤔

[@poisonivysaur4311]

Same

[@Xidphel]

"what goes Mach 4.2?!" A manhole cover.

[@al1rednam]

Too bad there wasn't a fast enough camera to measure that manhole covers speed more precisely...

[@namarazanchi]

The way he says Mach really annoys me

[@mranonymous481]

Here's what I found: A Mach number is the ratio of an object's speed in a given medium to the speed of sound in that medium.Mach 1, then, is the speed of sound, around 761 mph at sea level on a standard day. The term is also used as a metaphor for high speeds more generally. (I thought that otherwise you won't believe me)

[@namarazanchi]

@@mranonymous481 Yes

[@AManOnline.]

Only Half as Interesting viewers will get it

[@madssrensen9673]

Just like to point out he’s breaking big pieces of glass in shorts

[@Борис-е7ч]

Tough guy... I bet he is also frying his bacon bare-breasted.

[@kenhaley4]

It's safety glass. You can tell by the way it breaks--no sharp shards of glass or needles; just small, more or less uniform sized pieces. Not likely to cut when it breaks.

[@dfsseewsfewfg3511]

Connor, the android sent by CyberLife yeah, you’re right. Even though safety glasses lessen the danger of you getting hurt by glass shards, it doesn’t completely eliminate the danger. One example is car windows. Most cars have these safety glasses. But people still suffer injuries from shards falling on their body parts.

[@thejesuschrist]

These never cease to amaze me!

[@frederiklausing5071]

Jesus Christ youre like the new justin y

[@caidenmerritt1930]

captions at the start of the video and youll change your mind about sending them to heaven (im joking)

[@pmc614]

*_Dad?_*

[@demonwizard1]

*verified*

[@extrnalsorce4974]

Jesus Christ thank you Jesus Christ! Very cool.

[@troyjackson3400]

Not gonna lie, I didn’t even see the glass until they pointed it out

[@panickedhispanic5933]

Same

[@Skeem_YT]

fresheroaks same

[@darthnihilus3932]

Abelfatbutt same

[@moopybamboopy]

Same

[@magnummccormack8968]

I went to the comments to check If I wasn't the only one

[@cybersteel8]

i love how this channel is just two blokes having some fun with a camera for our enjoyment lmao wholesome af keep it up boys

[@michaelh.9686]

Who else didn’t notice the glass pane Dan was holding until they mentioned it at 0:24?

[@notnotfake226]

I didn’t notice it but I did notice a whale noise at 3:00

[@BoxFwog]

Yep

[@lemonnoob5333]

I didnt even know it was there until I saw this comment

[@DOSTalks]

... that’s the joke

[@therake9599]

Me

[@ericklorenzo4772]

Not as fast as KZbin rewind dislike rate

[@joeshmoe12301230]

BOOM! Got em...

[@killerking8363]

Erick Lorenzo lol

[@goldengameA]

We don't have the tech to see something that fast yet

[@MoreAvier]

Lets go lol

[@HiloYT]

400th like

[@xrox360]

2:10 The ice after Scrat places his acorn in the Ice Age movies

[@GRUHHHH1006]

Lol

[@rainbowangel5264]

My confidence after seeing my grades...

[@mallgoth]

@@rainbowangel5264 I felt this

[@waitselljones8068]

14.1 million subscribers, 14.1 million views. The ultimate in efficiency

[@vghnmj5523]

I didnt notice the glass in the beginning lmao

[@TheBestGrapefruitGuy]

Me neither 😂😀😝😛😜

[@ronaldburrelljr.226]

Scrolled through the comments just to make sure I wasn’t the only one 😭

[@dogfart1237]

i did

[@davidm4728]

ya i didnt see it at first. i wish they would have used the glass that dosent crack like this

[@incomprehension7571]

@@dogfart1237 r/iamverybadass

[@jasonwoodring4479]

"Got a church window?" is one of my favorite lines ever on this channel

[@luxdeitine4882]

Jason Woodring am I the only one who's ever wanted to remove church windows and replace them with lgbt pride mosaics

[@Pao234_]

@@luxdeitine4882 I really hope you are

[@luxdeitine4882]

@@Pao234_ fair enough

[@gamer-tn4yy]

@@luxdeitine4882 bro you poor thing. #didn'tdeservethemean

[@animalmother556x45]

..............as an avid firearm "guy" I feel the need to put this into some perspective for others. The velocity of a bullet fired from an M4 Carbine (used by the US military) is approximately 3,000 feet per second when that bullet comes out of the muzzle. When firing one at 100, or even 200 yards (people that are used to metric can think of them as meters...it is close enough for this example) the bullet impacts your target basically instantaneously from the perspective of the shooter. So.....I guess.....if you had a piece of glass 100 yards long...it would beat a 5.56 in a 100 yard foot race. That blows my stupid little mind. Holy shat. Furthermore...there are VERY few rifle rounds that even approach this speed. If you can get 4,000 feet per second out of a rifle, it is screaming fast. There MIGHT be a rifle that could keep up with this glass, but I don't know what it would be.

[@greggreg6975]

a 40 grain round from a 22-250 is about 4100/4200 fps! i think the .22 swift is a bit faster however ive never shot one. 😁

[@YouPlague]

@@greggreg6975 5.56mm is a .22 projectile

[@michaeltempsch5282]

[Some] railguns... USN in one test got a muzzle velocity of 8268 ft/s

[@animalmother556x45]

@@greggreg6975 Yes, but not 4,700...that was the whole point of my comment

[@animalmother556x45]

@@michaeltempsch5282 Yes, notice I was specifically referring to "rifles" as more people have contact with rifles than railguns.

[@kit2770]

I've always wondered how fast glass cracked. Now I know. Thank you, Slow-mo Guys.

[@polish_filipino]

0:20 I didn't realize anything was there till they pointed it out. That's one clear piece of glass

[@Bradsmit]

Polish Filipino can you watch my new vlog and tell me if it’s good or not

[@jaymesyt]

@Shambles1980TRealOne We didn't watch vlogs in 2001

[@toothpastecreature]

Please don't advertise here

[@REMOVEDREDACTED]

You guys should film macro shots of insects walking and there joints moving, like a ant or a centipede. I think that would look cool.

[@Sam-iu8nb]

I love this idea.

[@Emily-yz9zd]

Me too!

[@Yonatan24]

Bump

[@TheDanyschannel]

Would be awesome, unfortunately macro + high speed require stupid amounts of light. I'm talking tens if not hundreds more light than the brightest noon sunlight. Would probably heat up any insect to the point of killing it in seconds. Check out Tesla500, he did a high speed macro shot of a phonograph needle, took him some serious light sources and melted some plastic. Cheers

[@BensChannel-rn7ge]

I did a slo motion of a snapping turtle bite

[@mobiegaming4240]

0:33 I legit didn’t even know he was holding glass

[@FilesFromTheFearVault]

same, i didnt even realise until they pointed it out

[@sagemadara1265]

Same lol

[@Summon_Ls]

I was on my phone so I didn't realized...

[@silent3956]

Same

[@GANGST]

Mobie Gaming I knew they were holding the glass.

[@grimreaper1542]

Dan, "How much can you see?" Gav, "Bloody stupid, this is." Me, "Is that an answer? Sure."

[@Ensign_Cthulhu]

5:46 Questions: 1) Could the crack propagation have been altered by the thin coat of paint over the glass which lends it a bit of integrity? 2) The Mach number is a useful layman's yardstick but the speed of sound in glass must be different from the speed of sound in air, and you might have drawn attention to that fact. It would not be a surprise to learn that said speed of sound in glass is in fact equal to the crack propagation rate.

[@1994AustinSmith]

I'm not these guys, but here's my 2 cents. 1) It's still supersonic, by at least 4*. *Practically* instantaneous. 2) Yeah, material may alter the speed of sound. The material also alters light, but we still measure by it. It's not like we can make "glass mach" or "water mach" a unit of speed (except in America, where we measure in washing machines before using metric system.)

[@jinglemyberries866]

Here is something interesting, maybe: How fast can cracks move? This question is not only of significance to safety engineering but also to earthquake dynamics. There are three fundamental wave speeds in solids. In order of increasing magnitude, they are the Rayleigh wave speed, or the speed of sound on a solid surface, the shear (transverse) wave speed and the longitudinal wave speed. Existing theories of fracture have led many scientists to believe that the Rayleigh wave speed is the limiting speed of crack propagation. Is this really true? Glass breaks, rubber bursts-there are numerous ways how materials can fail under extreme conditions. However, many of the atomic mechanisms of materials failure still remain a mystery. Some materials harden when they are stretched, others soften under large deformation. This phenomenon is referred to as hyperelasticity. We study the dynamics of cracks using the world's most powerful computers, whereby the motion of every single atom in the material is calculated according to Newton's laws of motion. Combining theoretical considerations and large scale molecular dynamics simulations, we derived the conditions under which hyperelasticity governs dynamic fracture. We discovered that cracks can propagate supersonically when hyperelasticity, the elasticity at large strains, becomes dominant within a zone of high energy transport near the crack tip. This is important in understanding the dynamics of earthquakes or nucleation and propagation of cracks in aircrafts and space shuttles. The results are in clear contrast to classical theories in which the speed of elastic waves was considered the limiting speed of fracture, analogous to the speed of light in the theory of relativity (M.J. Buehler et al., Nature 426 , pp. 141-146 , 2003).

[@mizutani2144]

I didn’t realize he was holding glass in the intro...

[@lynahussein7450]

Anton H me to

[@AndreaRenwick]

Neither did I

[@abdelrahmanaziz5735]

Me to

[@TheCaptainJaes]

Same lol

[@TheToastOnFire]

Same... I feel stupid...

[@SmellTheCheeeez]

Dan, you probably should have worn some pants for that...

[@AmeerolisaRa-cw3qg]

Sean Hearrell That’s what I was thinking.

[@bloodytosser1]

It's safety glass, so there aren't large razor sharp edges, but yeah.

[@TheEthanEdge]

You're lucky he wore goggles and gloves tbh.

[@Sharpless2]

and also a respiratory system with 1500 liter oxygene tanks and 2 bomb suits? seriously...

[@photonicpiston9231]

And here i am thinking it’s a camo joke.

[@OLIVE_MANN]

I didn’t even notice the glass until you pointed it out

[@just-a-silly-goofy-guy]

Not as fast as my self esteem broke

[@manuelvelardez2466]

Dont kermit suicide

[@CoolSquirrel1522]

Kermit sewer slide

[@mrpizzapi3867]

kremit the frog ooooh edgy

[@unicorn7337]

Kermit skewer died.

[@jortand]

How do you break something that was never there?

[@Holden_McHock]

Lol who else didnt notice dan was even holding the glass???

[@harleyss]

If you didn’t say that I wouldn’t have of known 😂

[@Zerarkk]

They wouldent have said anything and i would say no there was no glass

[@arturofernandez4058]

5:40 Clarifications from an Aerospace Engineering student. Spaceships don't go at mach speeds because there is no air in space, so you cannot go supersonic. But velocities above Mach 5 exist, they are called hypersonic. So far the only thing that reaches those speeds are bodies returning from space during the descent, called reentry bodies, or atmospheric entry bodies.

[@jamesmnguyen]

@@arturofernandez4058 I think you commented on the wrong thread

[@jdrmurphy4141]

I alwasy skip the first ten 20 or 30 secs of any video so i had ro go back to see it. And still didnt get it for a bit.

[@ontheBrightsiide]

6:04 I think that was the smartest thing I've ever heard Dan say in a video

[@kappn4748]

Gav and Dan: Have an ultra high speed camera probably capable of shooting at speeds of over 50,000 fps, amazing technology at their fingertips. Also Gav and Dan: Glass is cool.

[@DinnerForkTongue]

SCIENCE!

[@andru4474]

Teacher: give me one fast thing in the world Me: a glass breaking Teacher: how is that fast? Me: trust me, it's very fast

[@NEWAGEANDERSON]

Legendary Andru just say light.

[@thesandwich5321]

Is light 'in the world'? ...hm...

[@jjcondado]

You can also back it up by saying it goes mach 4 speed, which is too fast for the human eyes to see properly, now if the teacher says then it should make a sonic boom, say that it depends on the size of the item, a glass that size clearly makes a loud shatter, not making a sonic boom

[@johnhenderson5041]

@@thesandwich5321 ...yes

[@trueaidooo]

@@thesandwich5321 can you see things?

[@CreativoErratico]

So we can all agree you guys now have to make a giant round glass video.

[@Shearper2]

i'd be down to see that

[@roronoaz4lyfe1947]

Yess!

[@Nitram4392]

Yes.

[@LameMule]

They better.

[@projectaudeo]

Yes they should

[@keeghanyule6465]

The slow mo guys: now if we shrink our horizontal and vertical view we can increase our frame rate up to 481 500 frames a second PC gamer frantically scribling on a piece of scrap paper: IM LISTENING

[@egg4444]

y e s

[@paulopereira47]

The same gamer:what kind of alien graphics card have you bought and where can I get it

[@oorohbooroz1781]

*laughs in 8k in just a couple months*

[@urayi8008]

laugh in 144p 5fps

[@Project_VideoGame]

*laughs in 8K and 300 fps*

[@glasstransport]

This is important. PLEASE READ. As a lifelong hands-on glass guy (cutter of up to 1" thick, custom flat glass of all kinds and very much more.) Please know the difference between laminated glass and tempered glass. What you have there is TEMPERED. Break a car windshield vs. side or rear window. Only the windshield is LAMINATED. That being said, this is GREAT!!! I have an old vid I slowed as much as I could (not much) and it was quite interesting. Three layers of glass laminated together, the center one being tempered. Installed it in a restaurant, then purposely broke the tempered piece. We call it Crackle Glass. The speed at which tempered glass breaks has always been something I wondered about. THANK YOU! I'd like to see you do pretty much the same experiment with all different thicknesses and compare the speed.

[@GabrielsLogic]

8:47 it appears dan knew the difference and gav did not 😅

[@aldozulfikar54]

*_Not that fast compared to 2018 youtube rewind disliker growth_*

[@guyfriedman295]

Lol good one

[@guyfriedman295]

Accurate 2

[@beerenmusli8220]

Good one : )

[@LYRINIZE]

These thumbnails are so attractive

[@jolliemollie3082]

Haha for once

[@Pvlogs22]

LYRINIZE - 8D Music GREAT CONTENT! Mind checking out the my channel and subscribing so you don’t miss some great content!? Thanks! 👏🏼🤙🏼

[@Ferniiiii]

Ikr? The guy is pretty good looking

[@pretzelking4618]

PIERCE FIT Lol go away with your self advertising

[@wadsome2120]

"If you love it so much then why don't you marry it?"

[@roromad9603]

If i was your neighbor, i would build a deck so i could just watch you guys do your stuff. better than tv.

[@mr.e2297]

But no slow mo

[@gildedbear5355]

@@mr.e2297 you build the deck to watch and then they invite you to see the slo mo and you slowly become the third member of the slo mo guys.

[@theprophet5250]

The human race needed this

[@LynxArcane]

''And for the international audience...''' THANKS GOD

[@ElephoontOfTheShapes]

I was looking for this comment, was getting worried when they were talking about 'a foot'.

[@maruftim]

yeah lol

[@LynxArcane]

I'm really curious how people thinks that "Thank you" can be used as an offensive term. I liked the content in the video, found it really interesting and REALLY thanked the fact that they converted the measurement unit. (cause, you know, that doesn't usually happens). I like physics. I found it really cool how the breaking of the glass goes in a "wave" form as an energy. Calm down peeps. Peace.

[@SirTatManTat]

@@douganderson7002 Yes? lol. I have no concept of miles per hour or feet in large amounts. Metres and kilometres allow me to directly compare the numbers to the knowledge I have e.g speed of cars distance of roads and trips. Of course someone's understanding suddenly increases with a different unit of measurement, literally no different than a different language if you never use the other measurements.

[@pedor5965]

@@douganderson7002 Hey, I walked like 2 ὄργυια from here to my kitchen, I used a ancient greek unit of measurement but that doesn't change your understanding of this sentence at all right?

[@kale6991]

7:57 Gav: “it just looks like a software wipe” Dan: “it just instantly turns to like lizard skin”

[@AndrewVelonis]

Yeah, we heard them say that.

[@senilegoldsmith4112]

"Wot goes mach 4.2?Probably a spaceship" TL;DR: Yes, a spaceship. The SR71 Blackbird had a recorded top speed of 3.5, however it's true top speed is still classified. In an interview with a former pilot, he recalled one of his missions over I think Germany, (probably off on that one) having a total of three missiles fired at him, and top performance was in order. Tilting the throttle to the maximum, engaging full afterburners, the two engines on that monster outran all three without any problem. When the interviewer asked how fast the blackbird took them in that moment, the pilot wouldn't say, only that it easily pushed them to mach speeds they had never seen yet.

[@debott4538]

Or, you know, the speed of sound traveling through glass. ;)

[@kam2597]

NEEEEEEEEEEEERRRRRRRDDDD

[@senilegoldsmith4112]

@@kam2597 you're right :D

[@kam2597]

@@senilegoldsmith4112 :D

[@darkmoonthedirewolf9231]

@@kam2597 😹

[@LyricsTheDustBunny]

This video needs to be for schools. The math was great and I learned something new.

[@RANDOMstuffanimation]

0:21 I did not notice that glass XD

[@Skysiax]

RANDOMstuff animation I did not notice you watch this channel m8

[@Therealseegs]

Me too

[@wsl10op44]

Can you guys do candle wax drop on water really curious how they form in slow mo

[@stuartrobertson8211]

I honestly didn't see the glass at first

[@B0neyKingofN0where]

BRAH SAME

[@lukxd3225]

Hold up, he held glass?!

[@oaegates]

I literally didn't even see the glass in the intro until Dan grabbed it.

[@philipstephenson6118]

Am I the only one who didn’t notice the glass Dan was holding at the start until they pointed it out? 😂😂😂

[@tequilasunset6567]

Philip Stephenson thats the joke

[@teamcyeborg]

Windex!

[@gerardlulinda4252]

I didnt either 😂

[@bigby9865]

I know I am not the only one who didn't see the glass 0:23

[@Orangeman-xv6zu]

Güççî Bëê you are very right 👍

[@princessblueskys721]

😂👍

[@sultanhanga]

I just noticed that😂

[@jayfromdacity9069]

Everybody saw the glass

[@rk3340]

CRAZY JAY I didn’t

[@ApheXMalign]

The crack propagates at the speed of sound. It just so happens that the speed of sound is different in glass vs air. The speed of sound in water is about mach 4.3 so I imagine your measurement is really quite accurate.

[@indigophoenix12]

So Baysed that answers the question I was going to ask, which was, does the speed of the cracking glass tell you the speed of sound through glass? So, thanks!

[@charlesb3801]

Mach is relative to the speed of sound. So the speed of sound in water is mach 1. Because it's the speed of sound.

[@ApheXMalign]

@@charlesb3801 Actually mach is fixed in its relation to air. Mach isn't just the speed of sound. Its the speed of sound in air. Check out the wikipedia article, it's basically this comment thread.

[@charlesb3801]

@@ApheXMalign incorrect, it is in relationship to pressure. If mach were a static number, than it would just be some invented useless unit of measurement.

[@chrimony]

@@ApheXMalign: I checked the Wikipedia article, and Charles B. is right, and you are wrong. Funny that you would reference that but are unable to read and understand what it says: "By definition, at Mach 1, the local flow velocity u is equal to the speed of sound." And, "The local speed of sound, and thereby the Mach number, depends on the condition of the surrounding medium, in particular the temperature." Air being one type of medium, water another, and glass another, etc. Using "mach 1" to refer to air in unscientifically correct, though colloquially people will know what you are talking about.

[@lewiskelly14]

You're getting a thumbs up from me for catering for your international audience

[@rafaycheema7643]

Glass cracking: I'm fast AF boi Slow mo guys: Hold my beer

[@GhostlyToilet]

HEwO

[@shawnsuggs7559]

It should be, *Wait... That's illegal*

[@PlotChat]

Rafay Cheema: I’m fast AF boi Me: That’s dead AF boi come on, my name’s even boring

[@mr.turtle7079]

Yes

[@haku5637]

Slow mo guys: hold my camera

[@son9798]

Thx for using global measurements!

[@philipnielsen1170]

Me

[@ahfazuyt1397]

You see this lionel mesi

[@bitai683]

glide to globul

[@SirFloofy001]

I hate when someone makes a video of something moving very fast "oh its 7000 feet per second" and leave it at that. I live in the USA and honestly 7000 feet per second has no meaning to me. Once you pass mach 1 all other measurements just become obscenely large numbers that you cant visualize where as the mach scale is easy to visualize "its going mach 4" its going 4 times faster then the speed of sound

[@colinhall7778]

The daft thing is, both of these guys are British and we use the metric system here.

[@nathanschmick9681]

I want a video showing how fast two liquid droplets will join surface tension and become one drop. You could do them two different colors.

[@JordanYee]

Pretty cool idea, although my intuition wants to say that at that level of precision, colored dyes might affect the surface tension! 🤔

[@masterraceofeverything4504]

They did it once

[@Robert-yf1kn]

If the earth really spins i want a video showing a helicoper hovering over a building in one position showing everything on the surface of the earth moving east.

[@Soken50]

@@Robert-yf1kn that's not how reality works

[@Robert-yf1kn]

@@Soken50 You dont understand reality then,research why the earth does not spin.

[@yeetusmeetusfeetus1273]

I am rewatching this video after a while and still didn’t notice the glass

[@silent596]

Same though, 10 months later. I've seen this like 20 times.

[@jetpackerjosh4061]

Still better than KZbin Rewind

[@lemonlime536]

You mean way better than youtube rewind

[@preachey]

why are you even comparing this to rewind

[@lemonlime536]

@@preachey ikr

[@lemonlime536]

@John DHill bro why?

[@shekhar7singh]

Everything is better than KZbin rewind, that is most disliked video.

[@dmaninisweener3862]

Who else didn’t see the glass in front of his face at the beginning?

[@mohnjarston2503]

dmaninisweener me

[@AndyGamingg]

lol me

[@johnniewalker39]

#MeToo Bad joke, sry

[@blahblah9036]

I literally went back and watched the whole beginning again to make sure there wasn't any clever editing. Nope, I'm just not very observant...

[@LorenzoL05]

Meeee

[@Kaskobi]

SlowMoGuys x HowToBasic collab when?

[@jediael9906]

When HowToBasic becomes mentally stable

[@LilKat]

hello there

[@AvoxionYT]

"How fast do eggs crack?"

[@nova_vista]

I'd be afraid he'd just start throwing eggs at them xD

[@ashcook2975]

Kaskobi I’m a lanchpadder and I love your vids like if you are to

[@sardorbek6399]

The guys break glasses out loud. Neighbours: Omg, that family must be having a messy divorce

[@mrnuke999]

I love how Slo Mo Guys Gavin and Achievement Hunter Gavin are almost complete opposites, and yet cause equal amounts of broken glass.

[@techcamisado4058]

But still the English nose

[@nitrokiller9959]

Btw. How’s that 14 ft glass circle coming

[@Madmuli]

They're currently making plans on raiding the town's church

[@LuciferMorningstar-ju3bw]

Wijnand Wetsteijn ill help, my brothers pretty chill.

[@LuciferMorningstar-ju3bw]

Ties de Jong well yes but actually no

[@CurtisRu]

Nitrokiller 99 I’m fat

[@lukejg4]

I didn’t even notice the glass Dan was holding at the start of the video.

[@templecatt]

I wonder how many people here cracked their phone screen, felt shocked, pondered about it, then searched up this video out of curiosity. because now the number is at least one.

[@animamundii]

6:25 - At this moment all flat earthers' heads exploded when they heard it as their tiny brains can't comprehend it. Nice video btw

[@txxthless874]

@Goda Skėrė delete your account.

[@andrewarnold9246]

@Goda Skėrė It's too dangerous here. Your kind is frowned upon in this realm.

[@TheDarkWarrior137]

Meanwhile there's me: "How did all these squares make a circle?!"

[@salomonhielmann]

what they still exist the flat earthers no way it's not 1800's century it's 2019 what C'mon really. or is that a joke please be a joke😊😂

[@KamiRecordsOfficial]

*Top 3 unsolved cases:* *1: Area 51 aliens* *2: Bermuda Triangle* *3: YT recommendations*

[@KamiRecordsOfficial]

@@QueueMaster69 ikr

[@mythicalgaming5605]

4: your name

[@1967buickriviera]

Optimum_ BeatZ KZbin recommendations should be first lol

[@AlexandreBugado]

I know how it works. YT will always recommend what you are most looking for. Like, if you are searching for lots of phone's benchmarks and tests, YT will reccomend you *the 10 strongest animals on earth* , because it is 519% related to phones

[@ThankaNChettaN77]

Yt algorithms

[@MindGoblin195]

When they explain the curved shockwave travelling through the glass and becoming flat, it's a cool demonstration of what happens with electromagnetic waves at far distances, for example with antennas. The wave starts out spherical, but in the far-field range it can be approximated by a plane wave because of this same phenomenon. Pretty cool!

[@MrGOLDENCUPCAKE1]

It's follows the inverse square law

[@ankushanni2323]

"45°" "Ohh that's naughty u never do that!" "Bloody naughty innit" Best lines

[@jerebenn3961]

I slowed down the video to make it slower. I AM THE NEW SLOW MO GUY!!!!!

[@jennyberger8229]

2:10 *snap* Mr. stark, I don’t feel so good

[@radjiwadji]

HAHAHHHAHAH NICE

[@Gary924hsus8f]

Lel

[@tristinreilly9604]

Okay KZbin, I watched it. Relax

[@landayly4464]

subscribe

[@XxGreyShowsxX]

Landayly The KZbin Gods will not be satisfied until you Subscribe

[@FERRARIDUDETV]

Just about to comment this, honestly KZbin what are you doing

[@nolearystream]

The famous wasp-filled ceiling fan! I love going back to the older videos and seeing stuff that Gav has mentioned on F**kface!

[@n3lis94]

Hey guys, I hope you end up reading this as I have a quite relevant suggestion. As far as I know, a crack propagates through the material at the speed of sound in that material. I googled the speed of sound of glass before seeing the results (about 4500 m/s) and was surprised to see the crack was far slower. However you used laminated glass which uses a thermoplast to reinforce the glass. I also looked for those and the speeds of sound in various thermoplasts is in the ballpark 1000-2500 m/s. I expect the fact that it is laminated glass slows the crack. It would be really cool if you tried 'pure' glass as well and see if the crack is three times as fast as I expect. Otherwise cheers nice video!

[@WaylonFlinn]

I did the same thing. Good job researching the discrepancy. I'd also like to see this repeated on untreated glass. Also, apparently diamond has a much higher propagation speed. That would be fun to see. ;)

[@n3lis94]

@@WaylonFlinn thanks, yes that would be really cool haha. But sadly I think even the slow mo guys won't be able to pull a 1 meter slab of diamond out of their pockets :p.

[@glasstransport]

Sorry folks, that glass is TEMPERED, NOT LAMINATED! Lifelong hands-on glass guy.

[@ORe0W]

Them: What’s that fast? My brain: glass

[@mastersy9359]

Bruuh😒

[@LukeFaulkner]

Trending in UK - congrats guys! A new subscriber here.

[@bridgepointgroup]

haha I came from trending too

[@dupontofficial]

m3 too

[@stardust4001]

Love your videos 😃

[@LukeFaulkner]

@@stardust4001 Thank you! 😊

[@kamrynsmart9151]

When I watched it, I never saw the glass at the beginning, but after its revealed, I can't stop noticing it.

[@OGBeefStew]

not as fast as my bookworm adventures deluxe speedrun time

[@Konclan]

Beef Stew this is truth

[@thecuriousone1721]

We need a sequel to bookworm adventures

[@ch.illmatic]

Why do I always see you dude,😂

[@michaelgeorge2231]

the new justin y

[@dragonmage1208]

Go bother dunkey again

[@memd777]

can you record some magic tricks in slow motion ????

[@walidsadi6647]

lol

[@killwilbur7213]

Yes. That's a video worth the crew Gavin

[@sweetegg]

That would be bad idea considering copyright in the magic industry and such

[@killwilbur7213]

@@sweetegg I think they could enchant the Terms and Conditions

[@fos1451]

@@sweetegg I don't know magic is copyright, lol

[@raxorbin]

Mach speed should be calculated relative to the speed of sound in glass . So it’s more like Mach 0,3, if you hit one end of the glass the shock will move at the speed of sound in glass.

[@cedarstuff]

I don't think they are science people.

[@oscantes]

Nice to remember. Edit: Ok nevermind :D

[@raver4lyfe16]

Sound has nothing to do with the breaking of the glass the sound is a byproduct of the glass shattering releasing pressure within the glass causing pressure waves that propagate as sound, if you watch closely their original calculation of Mach 4.2 is accurate we see the glass crack the entire length before any sound

[@Alucard-gt1zf]

raxorbin Mach is a constant measurement of speed. So no they are in fact right with it being 4.2

[@evaahh9584]

cedarstuff I don’t think he is, speed isn’t subjective, if you go at a speed of 3m/S and you go 100 meters it doesn’t mean you will be going any faster or slower than if you went 50 meters

[@tanyawells8981]

it's a circle because it's literally just a "sound" wave moving through the glass. the speed at which it breaks is the speed of sound through that material. typically at ~345m/s through air at sea level, the speed of sound is magnitudes faster through solid objects. (audio engineering is a hobby of mine - i obsess over this stuff) amazing video. i loved every second.

[@choimanin]

ironically, your comment was right under the actual comment which you stole from