Thunderf00t - 2023-07-01
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I'm pretty disappointed that the almighty Thunderf00t wasn't able to cause plastic deformation when compressing that zirconium in his fingers. I was hoping for a display of his power!!!
never reveal your power level
There's a reason he didn't show the part he was pressing into with his thumb. You would have seen the massive dimple he made.
@@rykehuss3435 he didn't have to go full power or anything, but he could have at least given us a show!
Its pretty clear that Thunderf00t was holding back to prove a point. You aren't going to make a good show if you compress the coil and the hunk of metal the same amount.
@@phillyphakename1255 You dont say
This is the longest way of saying the water equivalent of "It's not the fall that kills you, it's the sudden stop at the end". It's actually really interesting how a lot of our universe has these weird little counter intuitive physics that once you explain it makes perfect sense, but is totally not what you thought it would be.
Yes, but he basicly said that: its compressibility of water for some reason...
Saying that its the massive pressure like all those articles mention isnt wrong...Even without the sudden stop at the end - parking several trucks on every inch of your body isnt healthy...its like squeezing out toothpaste...
@@marasmorgean5813
I've been desperately trying to understand wtf he's talking about when he says it's the compression of water, not the pressure, that would have killed them. I am educated in physics but I assumed not as well as he is, and I've been trying to educate myself on how I'm wrong, but the longer I do that, the more I'm thinking that it's him that's wrong, and that the moment the structural integrity of the hull is compromised, the pressure will want to equalize immediately and the hull would collapse with incredible force due to the immense amount of water very quickly trying to fill the area of lower PRESSURE. The implosion that was heard also contradicts what he's saying and so does the debris field. I'm still open to being wrong but I don't think I am.
@@user-sj9mj3bf2m
Thunderfoot was wrong for two reasons. The density does kill you, but it's exactly why the water wouldn't just "fall" into the sub, it expands extremely rapidly and contrary to what he claimed, can't remember which video it was, it would not lose it's density right away as the massive body of water around it would continue to expand into the area with lower pressure. He is also wrong to say the sub wouldn't be affected and would merely break apart rather than implode. The sub definitely 100% imploded, thunderfoot is claiming otherwise.
@@ViperXXXXXXX Saying "It's not the pressure, it's the fact that the water is compressed" is stupidly nitpicky. A roundabout way of saying "It's the pressure differential", which... yeah, thanks, laypeople do actually intuitively get that. A low-pressure object suddenly exposed to a high-pressure environment, bad things happen. But give him a break, the man is trying to make a viral video.
@@SockPuppet80
That's very disappointing. If that's the case and he's just making a video that contradicts the official narrative for views, that instantly lowers someone's credibility to 0.
Seeing as water behaves like concrete when you hit it at high speeds, it's logical to assume the same applies when it hits you at high speeds
Essentially the crew of the titan was in the world's fastest hydraulic press with 346 atmospheres of pressure behind it
welcome to today's episode, this time we will be testing what happens when you put people into a hydraulic press.
I've hear that passed a certain speed it's actually softer to hit concrete than water.
My friend, the marine biologist, told me the fish around the Titanic have been eating allot of Five Guys lately.
ha!
' whats 'Five Guys ? '
@andymouse
It's an overrated burger place chain.
But the more important question is, how did you decide where to place your apostrophes?🤔
@@alphadawg81 yeah..I have no idea !! :)
Well... we humans intruded into their home both in 1912 and 2023.
It is actually very interesting. Even though practically speaking, there isn't much of a difference between this and how most people describe it, it is still interesting to get the nuanced details of what is actually going on.
Hydraulic Press Channel gives the visible demonstration using scaled down models and a compression chamber, and Thunderfoot adds the good amount of extra detail about how it's happening
I wonder how the crew actually meet their end. Were they killed by the impact of water against the hull or ripped apart by the gasses exiting their body. I read some stuff about wound ballistics and if i remember correctly, human tissue tears if hit at 600 m/s or greater. The speed of the water was higher, it would be interesting to see a computer simulation.
Gg😊
@@warrenfowler8049 I'd suspect a combination of being ripped to pieces by the high velocity water and being burned to a crisp as the air is compressed it's temperature starts to look like the inside of a diesel engine piston.
@@spidalack Did hope that TF video will address this "hot air" stuff with some precise calculations but oh well... I don't think there will be enough air volume to produce so much energy to burn all that matter inside, like I can imagine big submarine have enough air so that final compressed air bubble can reach very high temp and keep that temp for at least some millisecond(s) to burn stuff, but a few cubic meters of air getting compressed to something like 0.01 cub.m. even if it's really hot, do you think there would be enough total energy to burn stuff before it dissipates into water? I did some calculations and got roughly around 160 million joules of energy produced in the process, don't think I got those numbers right, but temperature seems to reach only around ~1300C and that's just for a millisecond in a small bubble(small surface area). Almost every YT video is full of those "temp of the sun, burned to ashes" stuff, but it would be interesting to see actual precise calculations made for a small air volume like titan was.
And yeah, that "uncompressed water bubble" expansion was really something new, no other video talks about water compression\decompression being involved.
Thunderfoot - "here is 17 minutes and 41 seconds more knowledge about water pressure than Stockton Rush knew"
Stockton - "up up down down left right left right B A start.... blooop"
When I was at Uni one of my lecturers told me about a mine accident when he was a student. A miner accidentally drilled into a neighbouring mine that was flooded with about 200m depth of water, the water in the neighbouring mine pushed the drill bit out of the hole rather violently, and the miner got about 60m of 3cm thick drill bit through his skull in rather less than a second. The water then proceeded to cut a hole in the granite wall behind where the miner had been standing. Water under pressure is not to be underestimated!
Did the miner die?
Look up the story of Phineas Gage if you're interested in oof injuries like that...
@@cholodude97 nah he was fine
Yikes. Yeah, they use pressurized water streams to cut rock and even diamonds, it can pretty much slice through anything under enough force. Anyone who has ever pressure washed a driveway or the like and held it (from a distance at that) against their bare skin would quickly come to appreciate how even the water from a relatively low power pressure washer can feel really sharp and hurt your skin.
@@cholodude97 probably had a headache though
Stockton Rush deserves the honour title "Captain Crunch"
get out. 😂
And the crunchiest at that!
I havent done physics in like 15 years and I found this really interesting. I love how you say that water is a very strong spring, really helps to visualize whats going on.
Young's Modulus in 3d.
He does explain things in very simple terms that us mere mortals can understand.
Everything is a spring, some things are just very stiff springs.
@@muskokamike127 That is why I love his content! I can usually keep up!
Also makes it more relatable, I reckon. Plenty of people have seen what happens when a really powerful spring decompresses, or even just a fairly weak spring. I've had the spring from a pen fling itself across the room, and I've seen a car spring embed itself into a wall; and those are springs that are smaller than me. A spring as large as the ocean? Well shit, no wonder the sub popped like a balloon.
Man, I love your channel. The only part I miss from the old days is actually having conversations with you. You probably don't remember me at all - but we've had some good chats. Thanks for keeping your content honest and interesting! :)
I still can't believe it survived its test runs.
Essentialy it's the dehaviland comet all over again
It survived more than just test runs. The sub wasn't completely unsuitable for this but it was only good for the first few dives.
Test runs maybe weakened the carbon fiber hull
@@DM-rc4yuso it was completely unsuitable.
@@rykehuss3435 Almost certainly
Don't forget it's essentially human beings layering "cloth" in opposing weave patterns.
At those pressures the tiniest imperfections and uneven layering would create small pressure differences and undue stress
This explains the physics of the process (which is excellent), but leaves out a few details. The implosion is so fast that it is essentially adiabatic. The velocity of the water is supersonic (in the 1 atm air). That forms a shock front preceded by a high temperature region. This shock front is similar to an explosive shock front, and will have a similar effect on the occupants. Furthermore, the potential energy available to the process is equivalent to about 50 kg of TNT, but entirely focussed on the interior. After the adiabatic compression phase, the potential has been converted into kinetic energy, which would be focused into a very small volume. The next phase then is explosive expansion to redistribute the energy into the environment. This process occurs in about one quarter of the time it takes for the compression, so is even more violent. In other words, there is essentially a two-step process, each involving the energy equivalent of a 50 kg of TNT explosion. That's a rediculously large amount of energy focussed into the occupants over the time of about one millisecond...
Absolutely, but reading around many people have been touting the incompressibility of water as a reason it would happen slowly and this mops all that up.
@@mandowarrior123 I'm getting really tired of people repeating the phrase "incompressibility of water" from high school like a parrot, completely ignoring the fact that water is still around 80 times more compressible than steel for example. Yes, it is virtually incompressible compared to air at pressures we are familiar with. It's just another story in these depths...
Every common hydraulic system in the industry has to take the compressibility of the hydrualic fluid into account. It's more compressible than water, but not by orders of magnitude. We can treat it the same way.
So paste.
@@ththththththththth water is incompressible, that’s why we can’t see black holes. Each is covered in a giant ocean they can’t swallow. All hail the might of dihydrogen monoxide!
So it was a diesel submarine…. Once
Very interesting! The only thing you didn't mention is that the gas bubble being compressed at such high velocities would also raise it's temperature into the tens of thousands of degrees, albeit ever so briefly.
It would be interesting for TF to look at this aspect, too, as the practical physics of the effects of this happening is not obvious to me.
Not quite that hot. I calculated adiabatic compression of air from 14.7 psi to 6000 psi (depth of about 13,800 feet). You get a temperature of about 1370 C, or 2500 F.
I’m a scientific dumbass but wouldn’t it be from the friction and speed of the release that would create the heat as a byproduct? Like if you rub your hands hard enough it can become extremely hot and that’s how you can make fire with two sticks. So something like that? Again I iknow nothing so
@@Inamonthortooo it is because compressing a gas increases it's energy and makes its temperature increase.
@@Inamonthortooo Have you never used a can of compressed air to clean a PC keyboard? Why does the can get so cold? There are no moving parts, so... what do you think? And what do you think the reverse (jamming the air back into the can) would do?
What an awesome explanation. This was a 3 months class in physics and chemistry in 17 minutes.
Absolutely well done, as always.
This video doesn't really explain to me how a 4% compression would make a substantial difference. So 25 liters leaking in would initially result in an extra 1 liter, for a total of 26 liters for the first tiny fraction of second of hull breach. Also, at no point does he explain how the human body compressing by 4% would be lethal. That seems like guesswork... are skulls fractured by that? If so obviously that should have been stated in the video.
I also don't understand why the final animation in the video shows an expansion of air, which never happens. The air compresses, not expands, so what in the world is the animation supposed to be of?
@@ethanlewis1453 The final animation is an expansion of water. The dark blue is the compressed water, the light blue is the region of water that has decompressed (by virtue of expanding into the sub).
The initial animations with a cube of water make it appear that the small amount of compression should be no big deal. The problem in this case is that the sub is surrounded by such a large volume of water that it won't be able to expand anywhere near 4% before the sub is full and the water enters a process of trying to reach a compression equilibrium again.
Thunderf00t's animation included a very large hull "rupture" - basically one entire end of the capsule opened to the compressed water. If a rupture was small (and stayed small), the flow rate of the water would probably be small enough that it wouldn't kill anyone instantly, unless maybe they were directly in the path of the resulting waterjet. I think part of the question is whether a rupture WOULD stay small. Typically with pressure differentials like this, the uniform roundness of the container is its main source of strength, and if that is compromised, the entire thing gets quickly crushed.
@@ethanlewis1453 I had trouble understanding it too.
I had trouble understanding it.
@@ethanlewis1453 As I understand it, 25litres don't 'leak' in. Water rushes in (it 'expands' in) at about the speed of sound through the first crack, which would rapidly widen the crack. Imagine water rushing at you at the speed of sound while the air you are in is being rapidly compressed to 1000atm in no time at all. The massive momentum of the water would cause a fairly large water hammer effect when it hits the inside surfaces of the sub! What I am imagining is that the sub more exploded than imploded. I could be wrong but I think this is what TF is saying.
Thank you Thunderf00t for explaining that water isn't incompressible. It's obviously compressible, anything is compressible. Water just happens to be so difficult to compress that it's functionally incompressible in your everyday life.
Are black holes compressible too?
To me... Thats incompressible.
@@kopasz777Nope, they’re the most compressed things in the universe 😁
@@captain_context9991locally incompressible
@@FlatEarthKiller
Well.... You couldnt compress a black hole any further, I guess is what he meant. But it doesnt really work with a black hole. As its the event horizon we can see. And thats not a physical thing at all.
"This is one of those things where you stop being biology and become physics instead."
that's my favorite explanation of what happened when the pressure hull failed.
When I want an explanation, I go to Thunderd00t and am always satisfied
Thunderd00d am I right?
Too right. Any engineering or scientific reviews thunderf00t’s are the go to for honest no BS explanation.
Same
@@blue-lu3iz here is what he satisfies him with 15:18 xD
I never expected the mass media to explain anything scientifically, let alone in a methodical fashion.
This actually explains a lot. I knew that such depths brought dangerous pressures, but I didn't really understand why something for example like a pinhole brought danger and not just a spray of water mist. Thank you Thunderf00t.
Well, we use pressurized water to cut things like stone normally. This is really bloody pressurised that it'll make the whole bigger very quickly.
A carefully machined, perfectly round pinhole, in a uniform material, would just spray water. Although it would be a fairly violent spray. The problem is that that's not how cracks form in materials under high pressure.
Diving gear survives by distributing the compression fairly evenly. Like an arch bridge, each part pushes against the next part over, and they keep each other in place. If one spot is weaker though, it compresses more. Tries to shrink closer to the center point, and pulls away from the material next to it.
Now if the bending were uniform, it would just push the two edges together. But since one side is compressing farther than the other, the two edges stop lining up. One side slips a bit into the interior of the sub.. and then decompresses into the air. Just a tiny bit. But now, that section of the material is weaker than the rest, so it bends toward the interior. Allowing more material to decompress....
This is how buckling happens. So one side of the material collapses inwards, ahead of the other side, and the material tears apart. Really fast. And then the water gets in between the two pieces, and pushes the edges inwards, into the interior, widening the hole. Uneven compression is bad news.
@@mandowarrior123 I haven't personally done it but I've had parts made and cut via waterjet. It produces a really nice clean cut and when grit is introduced to the stream, you can get a nice polished edge.
I always wanted one, there are videos online on how to build one using a pressure washer.
@@mukansamonkey Thanks for the insight!
These breakdowns so that even normal people can understand stuff, step by step, are why I am still subbed to you after all these years.
He's wrong, and I don't think he understands the fundamentals of pressure and density. His explanations sounded pretty incomplete but I quickly realized it's because his explanations are flat out wrong. It took me time to realize this so I wasn't a know it all.. I assumed I must be misunderstanding something, but it's definitely the pressure, and they definitely would have died instantly, and the implosion definitely happened.
I like how Thunderf00t explains everything from first principles and simple theoretical models. It gives you a way to apply the knowledge to other situations.
Humans can dive deeper than 100 meters and do it happily every day. I stopped watching after this
@@invictus99 according to a quick google, an average human cannot dive more than 100m. If you have special equipment and extensive experience you can dive a bit deeper than that.
" French freediver Arnaud Jerald has broken the deepest dive world record with bi-fins, descending to a depth of 120 metres " <-------- admittedly he's not your 'average' human being
@@WhoAmEye_WhoAreEwe that's a good argument for invictus99 above where he says that thunderf00t was so off his estimation so that he stopped watching (in disgust? not sure why). If the word record is 20% higher than the limit thunderfoot mentioned trying to set ballpark figures, it's fair to say that you should not stop watching because of that.
@@ctsirkass 👍
My bad, meant to included @invictus99 in my comment - as that's who I directed my reply to.
:)
My grandpa was a diver who did welding on oil rigs in the 50s-70s. Wore the old timey suit with the spherical helmet and everything. There's a very, very long list of horrific injuries and deaths that could and did/still do occur on those jobs from pressure issues and all the various equipment they used for pressure control. Even the toilets can kill you.
Byford Dolohin incident comes to mind. Eesh...
“Even the toilets can kill you”
As one U boat crew found out
@@SP-sy5nq But to be fair, toilets after a good Mexican or Indian meal can kill you anywhere, and anyone within a 10 meter radius!
ah yes, the getting queezed through the airhose magic trick.
The decompression chamber was a wild place (maybe it still is idk). Divers would have to be there for days or even a week or two. The air was stuffy, no modern air cleansing systems other than gasses to breathe, guys who refused to wash, guys sneaking alcohol, smoking cigarettes and watching Captain Kangaroo, and companies hiring prostitutes to be available in the decompression chamber.
Damnit, Thunderf00t! If science teachers were allowed to teach like this (and were willing to put in the work), imagine the literacy in the field. What a shame that we don’t. Big fan.
They are. You just don't get a teacher with a PhD until university. If some of these PhD level youtubers were allowed to make the grade school curriculum, the world would be a better place.
@@kolinstallman3788my mom is a PhD high school teacher 😁 but she is definitely a rare breed
My science teachers in 1970s secondary school,.Northern Ireland would have been all over an event like this. As it was, my brother still at the school testified to the fascination of the Challenger shuttle explosion. And then when the explanation emerged, science teachers in particular further elaborated
Breakdown of my calculations regarding the Titan implosion based on the information provided in this video, thanks Thunderf00t (correct me if I have any mistakes):
So the maximum speed water will decompress is 1,500m/s or Mach 4.3. In order to implode the submersible the surrounding water needs to be decompressed, the amount needed of water needed is relative to how compressed the water is, at 6,000 psi, water will compress by 2%, this means 50x the volume of the sub will need to be decompressed. I estimated the volume of water needed to fill the sub as 15m3, so we'd need 750m3 of water, this has a radius 5.6m. The decompression wave, which also travels at the speed of sound in water would take 3.7ms to decompress this amount of water (same time taken for the implosion), with a water speed of 398m/s or 890mph.
Thank you, the image that oceans are compressed down by 37 meters by gravity like a humongous spring is all I needed to understand how the sub got vaporized so violently.
I'm a plumber, I've always thought water couldn't be compressed, you just destroyed my reality,
On plumbing scales it can't, just if you try hard enough, anything can be compressed.
Larger rocky planets are more dense than smaller ones because the rock itself gets compressed more in their interiors, for example
Sound wouldn't be able to travel through water if it was "truly" incompressible, if you think about it.
Other than that, there is basically no practical application for the compressability of water in our "1 atm overworld". Only the Titan crew got the full compressed water physics experience.
What's a practical reality at scales we humans typically encounter often doesn't hold up at the extremes.
Another thing with air pressure:
We oil air tools with a couple of drops into the connector to keep them lubricated, running at say 8 Bar - no issue.
Hydrocarbons in a high pressure air system, like say on/in a fill nipple of a 300 Bar paintball/air rifle rig, it's explosive.
0.000508/MPa… about 2% at 3800m (slightly more because it is seawater and denser than fresh water).
@@allangibson8494 don't over complicate it, I unblock toilets and make water go hot,
I love how, when he wants to illustrate compressibility of metals, he has a bit of spring steel. but instead of having a block of steel (which would make sense as an illustration because "here steel and here also steel"), he has a block of zirconium supposedly just lying around
Thanks for explaining it!
I think it was the Hydraulic Press channel that made several tiny titanium subs and compressed them about ten months ago. The last one went to plan and all you heard was a snap and the sub was flattened.
Carbon fibre structures strength is on effects of stretching. It’s an excellent material for positive pressure chambers. But even though it works in structures with multidirectional loads - compression resistance is it’s points of weaknesses.
The mind boggles from the thought that someone decided it’s a good application to use for negative pressure chamber in a structure construction similar to a positive pressure chamber…
If you change the frame of reference, inside becomes outside and positive pressure becomes negative pressure duh. Genious.
@@spacejunk2186Wtf?
@@randomname4726 He's trying to do a joke, but not doing a great job of communicating that.
I don't think they thought of the carbon fibre layer as a layer resisting a certain amount of transmural delta-P (well, maybe they did, that would be mind boggling as you say). I can't really say what it's there for in their minds, though.
@@spacejunk2186The earth can also be considered flat, mathematically speaking...
Just make the sphere into a Mercator projection, and you're done!
Famous last words: "I decided to break some rules!"
Breaking human rules and the consequences aren’t so bad. It’s when you break the rules of physics that the consequences tend to be life limiting.
PS: Now I have the line “You can’t break the rules of physics Jim!” Going through my head.
@@psibug565"Ya canna brrrek the laws of physics laddie"
Well Phil it's a pleasure to actually to listen to you not debunking something or someone but explaining science in all it's glory.
The hull is also compressed. The speed of sound in the material of the hull will be even higher than that of water. Once the hull begins to fail, the point of the defect will accelerate into the inside of the hull. This will likely be the first material into the space and also what killed all the people before the water even got to them.
I see your point, but do you consider that we are talking about ~twice the speed of sound? At that speed it doesn't matter what will get to you first. When you get shot with a bullet, does it matter that first it pushed a piece of your shirt in you?
.. water at very high speeds hitting you(human tissue/bones), or vice-versa, is not unlike a water melon smashing against a concrete slab
@@fondoman3884 By time the water got to the bodies, I suspect it no longer mattered. Bits of the hull came in at a speed higher than the water. Remember the hull is several inches thick and is compressed by the external pressure.
@@simonspacek3670 In this case it doesn't matter but it still is a detail. I have also seen failures where the bulkhead forces its way done the inside of the tube. In this case the tube didn't go out of round but instead bell-mouthed and stretched to be large enough for the bulkhead to go down. This case will leave a hazardous artifact with compressed air trapped inside.
@@b.jellis It more likely reacts chemically to become CO2.
This was great stuff, and the compressability of water at those depths was completely new to me.
Like everyone else, I've watched lots of videos about this sub, yours is the only one where I've learnt something new. I knew nothing about the compression of water, although I did wonder why the implosion was so fast and no one else event hinted at it. Now I know! Thank you sir, I salute you.
Indeed. It also explains why the aftermath of an implosion looks like an explosion. The expanding water hits the opposite wall and explodes out the other way.
Speak for yourself. Other people watched exactly 0 videos about this sub (until TF's one) , because it's just dumb distraction involving the crazy lives of billionaires
@@YounesLayachi Lmao, what is your problem? He was speaking for himself. When you say "like everyone else" it does not literally mean "everyone". You'd know this if you had an ounce of human interaction in your live.
Note just for you: You actually can't measure human interaction in ounces. Before you come and nitpick that as well, lmao.
@@YounesLayachiOne of the passengers was a researcher - not living the crazy life of billionaires. You need to learn to live with the fact that some people has more money. Only a fool would hate people just for having more money...
@@perwestermark8920 Not a big believer in proportionality eh?
This is amazing. Finally, an elegant explanation of what pressure under water is.
That was interesting. I had not thought about the affect of water compressibility, just the immense pressure at depth. Once again I learned some physics from Thunderf00t.
With everything just glued together, it was probably impossible to check for slowly building damage to the sealings. So it would have survived a few depth runs but then some kind of bonding finally gave in.
They had a device to sonically check for material fracture. It seems like a silly idea to me, since fracture would be exponentially self-reinforcing. A crack makes the hull weaker, making it crack ever faster. The plan was to ascend quickly if they detected fracture over some threshold. In a way they did.
No, they could detect faults in the pressure hull. They changed the Carbon-fibre body in 2021 after about 4 dives.
OceanGate's corporate logo was basically: killing passengers for profit.
As they ignored all safety concerns and cut corners to save money. Such as using a viewport only rated for about 1/3 the depth they planned to operate at.
To this company "It is not their fault; if you die in their death-trap Sub; it is your fault for giving them your money"
@@sos_legio_primus9177 Has the bit about the viewport been confirmed in Titan as it was in 2023? OceanGate claims that the 1,300-m viewport was only on the prototype.
I don't think the seals would be a problem as the further you do down they more pressure is holding them together. The problem would likely have been fatigue to the carbon fiber. The view-port is homogeneous so they will know exactly what it can take and I don't think it would fatigue as quickly as the carbon fiber would
Carbon fiber and even bonds to the titanium could be tested. The machines that do it simply cost too much money for their tastes, so they didn't get em and basically hoped for the best because "safety is for wankers" was basically their attitude.
I've been on the edge of my seat for this video from you. Thank you.
My favourite part of a Tunderf00t video is when he says “water,” so this is probably my most favourite Thunderf00t video
Elon is going to have settlements on the ocean floor in 2 years, with a view of the titanic
his subs will land on their tails
As a custom knifemaker my clients often request carbon fiber for handles and while it is tough it is also fairly brittle so I was really surprised when I found they used it for the sub hull. I make sure to round all the surfaces as if you have square ones on the handle and drop it a chunk can break off sometimes quite easily.
It's weird they would chose to make it out of carbon fiber when it's usually used in applications like aerospace, aviation & motorsports, where you want something strong but also as lightweight as possible. Diving to great depths doesn't seem like the weight of the craft would be such an important factor compared to safety & hull integrity, when a simple fracture in the CF can cause the complete destruction of the hull and everyone inside.
I don't know if it was a money thing but I'm sure they're now very much regretting not going with a traditional steel or titanium hull like all other submersibles use and other experts advised them to do.
Carbon fiber has become a colloquialism for anything with carbon fiber set in a resin.
Composites are hugely complex. The resin and the type of fiber can have vastly different properties and wildly different outcomes.
@@QuasiMonkey It's because the CEO and half the engineers had no experience in building subs, they were all from the aerospace industry.
They used a material they were familiar with even though that material was unsuited to the task.
@@gavros9636yah he hired them cuz the experienced people he hired kept giving him push back lol wanted people he could easily push around
@@sjbechet1111 Whatever version of modified Carbon Fiber they used instead of steel or titanium, and to quote Ryan Gosling in the SNL Papyrus skit: "Whatever they did, IT WASN'T ENOUGH!"
Thanks Thunderf00t. But I still can't visualize incompressible water closing in at free fall. The Bernoulli equation through a hole in the sub shows water coming in at around 70 m/s.
The speed of expansion is just wow. Mind - blown
You are still one of the best science-communicators on the internet
unfortunately, mister ukraine fingernails is one of the best science communicators..
The hydraulic press channel once put a little steel submatine in a pressure chamber and after some time of nothing happening the sub violently imploded and became flat like a piece of paper.
And they put a carbon fiber tube with steel end caps in the same chamber 7 hours ago.
When the sub fails, a cubic meter of water beside the sub has 40 mega pascals on its ocean side, and just an atmosphere on its sub side. So the force is 40 mega newtons, mass is 1,000 kg, so that ton of water would accelerate toward the center of the sub at 40 kilo meters per second per second. I got 0.007 seconds for it to travel 1 meter across the sub, reaching a speed of 280 meters per second.
That ignores the springiness. So that's a good point. But even if it was incompressible, the water wouldn't fill the sub at freefall speed, because water surrounding the sub to a radius of 10 meters would only have to fall 3mm in order to fill in that cubic meter.
Not sure if that will make sense, or even if any of it is right in the first place, but thought I'd comment anyway : ) Great video as always.
2 cases are commonly discussed: "Implosion without water entering the vessel" ( initially at least ) or this case which desciribes "a hull breach".
In either case the water will "expand" with great force/speed as the air in the vessel is compressed/displaced.
Some people mention the "dieseling-effect", but the temperature rise due to compression and possible ignition of material is not comparable to the energy in the "expanding water" at these depth ( 3500m = 350atm ).
( For comparison, the compression cycle of a diesel engine is usually just around 2 mPa = 20atm and after ignition around 5 mPa = 50atm. )
Never thought about the compressibility being the important factor. Thanks for explaining.
So it's actually kinetic energy that kills you. The pressure compresses the water giving it potential energy. When the hull fails the potential energy is released as kinetic energy. In effect a sub at depth is surrounded by a bomb and the failure of the hull detonates it.
So the air doesn't turn hot and burn like other channels mentioned?
people tend to get entangled by different ways to describe the same thing. is it pressure? is it compression? etc.
things are in fact a little bit more complicated than f00t shows, but I cannot really explain it without writing down PDEs and what have you, so I'll just leave it at that
@@bendedstraw4294 That's probably not what kills you first.
That's an excellent way to describe it.
Easiest way to look at it is to look at a container at vacuum imploding.
It would be very interesting to take a 50% scale model of the titan carbon fibre and titanium bell hull and expose it to cycles of pressure in a hydrostatic test chamber simulating the pressures and temperature profiles of multiple dives… with strain gauges everywhere and cameras. Also take a model and compress it to failure with ultra high speed cameras to record the implosion event.
You wouldn't get an implosion in a small test chamber. You need a lot of high pressure water to expand as he pointed out.
When they test scale models you just see it crack, and then the pressure is relieved
@@zachary3777 thats the implosion happening, its just not as violent. you just dont have the explosive re-expansion afterwards because of the small volume of water.
Not 50% scale. But interesting anyway
https://youtu.be/BQGDwE3yMb0
The hydraulic press channel have just done a video trying to do this https://www.youtube.com/watch?v=BQGDwE3yMb0&t=727s
That's kinda what the creator of the sub should have done before any passengers embarked.
But it was cheaper to not do that.
@decentrifytech - 2023-07-01
As an ex nuke submariner, I've been following this story and looking at this company I get the feeling of another 'vaporware innovation' like Theranos, The Hyperloop or Nikola - but this time instead of people losing money, they lost their lives; as soon as I heard 'carbon fiber hull' and 'lost submarine' I knew it was over and shook my head.
There is a reason why submarines are made of steel and titanium and not carbon fiber. Steel and titanium have deformation before they give way, giving time to drive yourself up to the surface or emergency blow. Carbon fiber has no give - when it fails, it fails catastrophically. Anyone who has seen a carbon bikes or carbon auto parts blow apart knows that carbon fiber, though strong and light, fails instantly AND catastrophically where as steel and titanium have some 'deformation give.' If you look at a scanning electron microscope of steel or titanium vs carbon fiber, one can see carbon fiber weave and how 'porous' it is compared to metals. As thunderf00t mentioned resin epoxy which acts as sort of a bonding, filling and stiffening agent for the carbon fiber - but the characteristics of epoxy is that it is strong but very brittle.
One thing I have not heard that I want to mention pertains to the epoxy adhesion of the titanium rings and the carbon fiber hull. Hand applying epoxy and just 'hoping to get it right' is just horrible. If one of those titanium rings of off by half a degree, that is going to create unequal axial loading down the length of the hull; and given multiple pressure and temperature cycles, the potential disparity in tension/ compression is just (head shaking) ...no...just no. That's going to cause cracks in the hull and/or cause the epoxy to crack/ fail. And just one layer of that carbon fiber hull not laid down correctly, one trapped air bubble - and that's a time bomb. Anecdotally, if you look at how carbon fiber diving cylinders are laid, they are laid at axial angles unlike the radial lay of the OceanView sub (yes, the diving cylinders are highly pressurized compared to the subs, but that is a design consideration to think about when thinking about axial and radial tension and compression)
Another thing I noticed is that in some images, you can see condensation accumulating on the carbon fiber ring - which tells me that the sub had no moisture or CO2 management systems; moisture is bad for electronics and if I remember my basic chemistry right, H20 (from people's breath and condensation) + C02 from exhalation creates carbonic acid. How that might effect epoxy? Not sure just throwing that out there.
OceanView's hull integrity system is subpar; Naval submarine hulls and welds are x- rayed when constructed. Complete X-rays and ultrasounds should have been the very minimum of that carbon fiber hull after every dive. Salt water is unforgiving!
I have heard hearsay reports that this particular sub had cracks in the hull they knew about - if that turns out to be the case and they dove anyways, that is pure negligence. And OceanView had fired one of their engineers and sued him for voicing concerns over the hull - can we say that the CEO was full of hubris and trying to be a 'Theranos' unicorn?
The more that comes out about this sub...this is why STEM education is SO important - it can SAVE YOUR LIFE! Maybe your BUSTED! videos can save lives!
I've been watching you (thunderf00t) from the beginning and sincerely - thanks for putting the science perspective out there for the public for 15 plus years now.
@rabidbeaver167 - 2023-07-03
I don't even understand how that was all legal. Like there's no regulations? Lol
@ttextinction7273 - 2023-07-03
Appreciate your insights sir
@stampedetrail2003 - 2023-07-03
Just checking... you mean Ocean Gate ya?
@SenorZorros - 2023-07-03
@@rabidbeaver167 They made it a submersible and not a submarine specifically so it could be launched from international waters which, being international waters, have no regulations (except international law). This was done to avoid US regulations which would have squashed this project even faster than the sub imploded. Which also makes one wonder why you would trust a company that is explicitly avoiding safety standards...
@kukipett - 2023-07-03
As a professional in carbon fiber when i saw how the cylinder was made by just rolling the fiber along the axis without any cross wound i was flabergasted.
At the tube ends you will get the full cross section pressure only on the tube thickness surface and this is 4-5 times the pressure. And in this direction along the tube axis that rolled fiber gives no strength you just have the resin to hold the pressure and it will lead to deformation and fatigue, cracks and a failure.