An update from Sam, the scientist in the video! He says: "It's been great reading through your comments and seeing people excited and intrigued by our research. I thought it'd be useful to answer some of the common questions that keep cropping up: 1. Yes, high speed video/photography of explosions is nothing new. They did this all the way back in the 40s and it's famously how GI Taylor estimated the yield of the Trinity test. Our high speed video is not what gives us the new scientific insight, but it does help give us a steer as to what is going on, and it's a fantastic way to demonstrate what an alien world it is so close to an explosion (in time and space!) 2. Our pressure measurements from the MaCE rig do give us the new scientific insight. If you want to see an example of our recorded data then please feel free to read our recent paper (link in description), Figure 5. We're measuring pressures higher than the strength of normal steel that are applied and removed in 50 microseconds. For comparison, a blink lasts >100 milliseconds, so over two thousand times longer! 3. Scientists know a lot about nuclear explosions, that's true. There, the energy is released effectively instantaneously and effectively as a point-source. With high explosives, the reaction rates are comparatively slower. That means we have an ongoing chemical reaction that changes if/when the blast wave and fireball come into contact with structures. The exact loading applied to said structure is a function of the pressure-volume-energy state of the fireball, so there's an intricate dance between the two (pressure and reaction rates). This is where current models break down. Yes, even the sophisticated physics-based ones. 4. We're only just discovering the extent of our ignorance, because until now we simply haven't had the experimental data to compare to. We do know that these secondary reactions are significant, which makes explosions (from high explosives) so difficult to simulate, because we've measured explosions in normal air and in an almost pure nitrogen environment. 5. Yes, the mottled/bumpy surface of the fireball as it expands outwards is a genuine physical feature, and seen at larger scales too (see photos of the "Minor Scale" test). When we're performing tests that we intend to publish we form our explosives into a 3D-printed mould, but even then we still see these features. 6. We filmed at 250 thousand frames per second for this video, but our camera can go all the way to 10 million frames per second. Thank you once again for showing an interest in our research. Cool, innit?"
Harold Edgerton, who developed the camera that photographed the Trinity test, is my scientific hero. He's a rare giant in both the arts and sciences and is one of the reasons I became an electronics engineer. He's a great example of how scientifc outreach using advanced technology can shine a light on the world and inspire the general public at the same time.
@@KKsKrissvs121 while computers and such are fast nowdays, they likely are not fast enough to send the data about the explosion that fast. the only chanche would be to send the raw output from the sensor trough a wire, but you would still propaply only get about half to quater of it at max, and it would cost a few tens of thousands do to the camera breaking.
I’m imagining the researchers pausing for moment when Tom asked what the purpose of this was and they had to fight the urge to say “because explosions are cool”
@Borrego a Yudando Nah. The auto industry. Millions of deadly several-tons things with the power of several hundred horses that nobody bats an eye about whereever they are. THOSE are dangerous.
@@pepperypeppers2755 "Remember kids, the only difference between screwing around and science is writing it down." - Alex Jason/Adam Savage Edit: I got the quote slightly wrong. Fixed.
The actual data from this test didn't make it into the video (it's just a LOT of numbers), but there's a paper in the description for those so inclined! And this week's pinned-comment plug: the Technical Difficulties are back! A new season of four adventures from me, Chris, Gary and Matt over at th-cam.com/users/techdif - one every Thursday.
If you go to 5:06 and use the . button to go frame by frame, you can see that the ground lights up 1 frame before the explosion is visible. This is because the camera scans in "lines" of pixels top to bottom. When it was at the explosive material, it had not gone off yet, by the time it got to the ground, it had.
5:51 interesting to see the shockwave resonates the dust under the table. Wonder what impact this has on the signals within the data cables which run out from here and if a deflector would be beneficial
The dust is kicked up but I see no resonance. The shockwave through the air will hit the striped screen and bounce back. This could cause the appearance of a interference-pattern. I think the dust kicks up because the barrel restricts the flow of air underneath it. Also, the barrel's 4 wheels are pushed into the dirt, so they cause some disturbance too.
Oh hey, this is something I actually do active research and development on! We’ve actually gotten pretty good at making computer simulations of these kind of explosions using multi-phase physics models. The Kingery-Bulmash model that Tom mentioned is still used in places, but it’s ridiculously simple compared to real simulations.
I've always been curious: how do you wrangle the positive feedback from heating? Do you let it run wild but put a cap on transport rates, or what's the strategy?
And here I thought blowing things up industrially was fun. I really want to get into the research/engineering side of things, but that generally requires more education than I've got/am willing and able to acquire at this point.
@@cdavie5 That's such a good question. If you're modeling the chemistry, then the heat production will be limited by how much reactant is available. So like you say, it's limited by transport, either how fast fresh reactant can get in by diffusion, or how fast the heat can spread by thermal conductivity. Or in the case of a detonation, it's limited by the how fast the shock wave can travel and how much energy can be released by the material. In my case, we don't really model the detailed chemistry because it'd be so expensive. We have an equation of state for the energetic material, which controls the amount of energy and temperature that's released.
@@Krazylegz42 got any recommended reading for equation of state models? I’ve done some reading on impact constituent models like Johnson cook, but I had trouble finding a primer of shock EOS
Kinda same nowdays, there are a lot of theories that we have no way to prove but who knows, maybe 100 years later someone will prove or disprove them (string theory etc)
When you have people who dedicate their lives for their dreams, they excel. The entire lives of these scientists were composed of constant studying and creativity. Like Isaac Newton, he studied daily. And with his creativity, he began applying his knowledge to many other fields.
@@titan5064 idk if string theory will ever be falsifiable, it's just so out there, and they always say that they'll get evidence in the next decade. then again, we were able to disprove theories that explained dark energy as instead the universe existing on a 5d shape via closely measuring gravitational waves, so maybe we'll be able to someday.
It’s amazing how many things there are that people had theories about how they worked 100+ years ago, and yet we’re either no closer to actually knowing or we’re JUST getting into it, like this
I love how jealous Tom looked when he was told the camera recorded a quarter million FPS. Like, that was just as much a highlight for him as the explosion
The last two utterances in this video encapsulate why I watch Tom Scott videos: his genuine desire not only to allow people passionate about interesting things to explain them, but also to *get excited along with them*.
Tom, this has been a game changer video. I cannot understate how much this has solidified what I want to do as a career. I’m currently working on a forensic science degree and have been thinking of doing something like explosives and/or fires. Yes, I do definitely want to do this. This blew my mind up with it! Thank you!!
Wish I had this video about 4 months ago, my dissertation was about simulating fires and part of the background was saying why we couldn't/ it's so difficult to simulate explosions! Nice video once again 👌
Last year I worked for a MACV-SOG/SEAL veteran, who works for the Department of Defense. He’s been mapping the surface areas of expanding blast waves as an engineer. I learned new applications of Brownian Motion from him.
@@jonathanpfeffer3716despite the stereotype about soldiers being stupid you don’t become special forces if you’re dumb. Most of those guys could go get a college degree and be successful out of the military. The reason they stay in and get shot at is because they want to.
The multiscale/multiphysics and tiny timesteps required to simulate this stuff is so complicated. Data like this is used during validation and uncertainty quantification for models.
Ooh! The HSE labs :) fascinating place. Built on top of RAF Harpur Hill, in its day it was the second largest munitions dump in the country - a honeycomb of concrete bunkers built in a disused quarry before being backfilled to look like a hill again. Also one of the locations where the MOD dismantled and studied the German vengeance weapons of WW2...
Have you got any history about the area? This site is on top of hte hill and not near the tunnels. But we are very interested in the site and its history and always lookin for more information.
I get that its built for different forces and that, but its quite funny seeing this box delicately lowered to the ground by the forklift before it's blown up by an explosive
We had this problem when designing our detonation rig at the University of Southampton. We needed a way to collect experimental data that wasn't just qualitative, and it was incredibly difficult to find a sensor that we could expose directly to the detonation on the inside of a detonation chamber that could read data fast enough, resist the 3,000 Kelvin instantaneous temperature, and sustain anywhere from vacuum to 60 atmospheres of pressure. Using strain gauges is a cool idea to look at detonation wave speeds, but I don't see how they can read static pressure and temperature with time
It's amazing that we can understand so much about nature, yet be eluded by such basic things. Another example of this is the dynamics of a 2 wheeled vehicle such as a bicycle or motorcycle.
@@brennancork I just looked it up and it has not been done. It looks like theory is that the moving wheel creates a gyroscopic effect which keeps it upright but they did an experiment to eliminate the gyroscopic effect and it it still remained stable soooooo
The "kick vs push" question is similar to the "what is a dot?" one. if you look far enough, everything is a dot (just like everything is a kick if you speed it fast enough). It becomes interesting if you zoom in the other direction. :)
Interestingly enough this is a similar problem that we have in lightning research, in the sense that you cannot get close to the object you are studying. So maybe their research can also benefit lightning researchers in their efforts!
I suspect that the data gathered can be used to suppress or enhance explosions in the future. It is ever so. It’s also a constant that the researchers will present what the think sells the best.
Now do a video of you going through Heathrow security. I once visited an explosion test site and then had a very interesting discussion at the Airport…
I'm a pyrotech, we put all clothing worn during blasting in sealed bags in checked luggage. Nothing (even boots) that was near explosives goes on you or in your carry-on. I pass the swab testing 95% of the time and we have ID to cover the times we don't.
At 05:13 : Tom's got the face of someone who's going to spend the next 12 hours searching for the right frame 😅. Fortunately, it didn't take that long.
if I am not mistaken it's taught in the military to stay clear of walls during explosions exactly because of this double pressure from the blast and the bounce.
I feel like, as a result of so many encounters with so many different phenomena, Tom has begun to intuit some of the observations these scientists are making. A sort of "wait, wait, don't tell me! Let me see if I've got this right!" thing.
Great video Tom - but please for goodness sake get the slow mo guys there with a phantom camera! They did an amazing video with an explosion where you could clearly see the shockwave, initial blast wave and negative wave pressure.
That's true! I'm an FX artist and the start of the simulation is pretty weird, it looks cool because it's the magic of the cinema, it's based on real life but the actual application is very weird indeed lol
Reminds me of the shock waves reflected by the ground during air bursts of nuclear weapons (albeit on a much larger scale), which then interfere constructively and largely increase the force of the blast.
i genuinely feel like insights in this research can be changing the future of humanity, control over the force exerted at that precise a scale lets us make new engines, reactors, materials
Have you ever covered how factories stitch books with thread? I'm trying to get my brain around it and just can't. I haven't found any videos that go into how it works, at least not as well or detailed or complete as some do for fabric sewing.
@Dave Rosser It might be an older method than you are looking for, but Adam Savage just recently did some videos on bookbinding at a bookbinding museum with historical equipment. The person explaining things to Adam went into detail about how the equipment sewed the signatures.
I will say this, as I watched the regular explosion vs 'Hollywood' explosion a few hours ago(also you on fire), seeing it again in the beginning, you are probably the only person cheesing a smile the whole time, and it is glorious. 🥰
5:05 if you pause frame by frame you can see that the light from the explosion shows up on the ground faster than the camera can catch the light emitting from the actual explosive.
I need Tom Scott in my life. If I have to live vicariously, then he is the best route to travel. I have lost track of how many deep dives, and google earth expeditions i have done, because I wanted to know more about one of this snippets of fascinating info. Grammar is a goal, never for this me, myself, and I, to attain.
It’s that classic thing of asking, “yes, but why…?” over and over again… get closer, get smaller, see things in more depth… answer the ‘Why?’ at one scale and then ask, “But what happens at the molecular scale?”
We've been blowing things up for a long time; it's reasonable to think that. But anything chaotic is really hard to model. We don't really understand turbulent flow such as water in a stream either.
I used to work with a group of people who designed warheads, like HB 876 (I knew the guy who suggested the dimpled case) and BL 755. When I was paying attention they were modelling self forging fragments, which involved modelling the detonation of explosives and the forming of the metal plate that they were in contact with. Their experimental results corresponded very well with their model. So I'm surprised to hear, nearly 30 years later, that they didn't understand the explosion. It seemed like they understood it really well. This short range blast was actually far outside of their area of interest, by the time the plate started to move the explosion was discarded from calculations and the metal was just coasting to its final configuration (teardrop shape, pointy end first) and had already reached its maximum velocity.
All a warhead designer is interested in is the final effect, not the minutiae of the initial detonation. Final effect can be determined by the simple expedient of explosive testing, rather than by mathematical calculation. The explosive testing is going to happen anyway, so you cut to the chase and get a bigger bang for your buck.
@@JarrodFrates Exactly. HB 876 is an area denial mine. So it is dropped in a swarm and they are influence and time fuzed. If you look up JP233 or HADES you will see the dispensers. The mines have springs on the side which stand them up. If something drives over them , or knocks them over, they detonate. If you try to clear them with a dozer they are cunningly designed to tip towards the blade and fire the main EFP through the dozer. At random times they detonate and blast out a ring of small EFPs which 'interfere' with clearance efforts. If I remember right they are dangerous to several hundred meters. In JP233 they are dispensed around SG357 cratering munitions, so they crater a runway and surround the craters with mines that no sensible person would approach. In testing in the US the pilot missed the target area and dropped them in grass, they had to burn the grass then use three teams of snipers to detonate the mines from a safe distance.
I turned the volume up and started paying more attention at "...could save lives" and it immediately made me feel like a big utilitarian nerd instead of a just a vague general nerd.
tom i want you to know that i love your podcast lateral and will be absolutely crushed if it ever goes away, mentioning it here, because i didn't know it existed until recently.
did load of work on that site years ago where they were testing new gas pipeline systems. weeks wiring up strain gages and thousands of meters of cables back to the control building.
An update from Sam, the scientist in the video! He says: "It's been great reading through your comments and seeing people excited and intrigued by our research. I thought it'd be useful to answer some of the common questions that keep cropping up:
1. Yes, high speed video/photography of explosions is nothing new. They did this all the way back in the 40s and it's famously how GI Taylor estimated the yield of the Trinity test. Our high speed video is not what gives us the new scientific insight, but it does help give us a steer as to what is going on, and it's a fantastic way to demonstrate what an alien world it is so close to an explosion (in time and space!)
2. Our pressure measurements from the MaCE rig do give us the new scientific insight. If you want to see an example of our recorded data then please feel free to read our recent paper (link in description), Figure 5. We're measuring pressures higher than the strength of normal steel that are applied and removed in 50 microseconds. For comparison, a blink lasts >100 milliseconds, so over two thousand times longer!
3. Scientists know a lot about nuclear explosions, that's true. There, the energy is released effectively instantaneously and effectively as a point-source. With high explosives, the reaction rates are comparatively slower. That means we have an ongoing chemical reaction that changes if/when the blast wave and fireball come into contact with structures. The exact loading applied to said structure is a function of the pressure-volume-energy state of the fireball, so there's an intricate dance between the two (pressure and reaction rates). This is where current models break down. Yes, even the sophisticated physics-based ones.
4. We're only just discovering the extent of our ignorance, because until now we simply haven't had the experimental data to compare to. We do know that these secondary reactions are significant, which makes explosions (from high explosives) so difficult to simulate, because we've measured explosions in normal air and in an almost pure nitrogen environment.
5. Yes, the mottled/bumpy surface of the fireball as it expands outwards is a genuine physical feature, and seen at larger scales too (see photos of the "Minor Scale" test). When we're performing tests that we intend to publish we form our explosives into a 3D-printed mould, but even then we still see these features.
6. We filmed at 250 thousand frames per second for this video, but our camera can go all the way to 10 million frames per second.
Thank you once again for showing an interest in our research. Cool, innit?"
For even more explosions and high speed video from Sam and the team, come find us at Sheffield Blast! 💥
Appreciate the follow up information, very exciting stuff!
Harold Edgerton, who developed the camera that photographed the Trinity test, is my scientific hero. He's a rare giant in both the arts and sciences and is one of the reasons I became an electronics engineer. He's a great example of how scientifc outreach using advanced technology can shine a light on the world and inspire the general public at the same time.
That definitely is very cool!
Thanks for the paper. I enjoy the feeling of the "I know some of these words, but I'm glad someone knows the worth of them"
It does make sense why it's difficult to observe what happens in an explosion up close
You should be able to do it efficiently atleast once.
@@KKsKrissvs121 while computers and such are fast nowdays, they likely are not fast enough to send the data about the explosion that fast. the only chanche would be to send the raw output from the sensor trough a wire, but you would still propaply only get about half to quater of it at max, and it would cost a few tens of thousands do to the camera breaking.
couldn't they just send lasers through the expanding wave to measure the density changes? with that you could even make a 3d model of it...
@@tesafrack the light from the lasers will be reflected and refracted therefore producing inaccurate data, at least thats what i think.
It's easy though, just stand closer....
You can always tell it's going to be a cool video when we see High Visibility Tom Scott appear.
It's hard not to see High Visibility Tom Scott appear.
@@Pattoe He's hard to miss.
Then the high vis worked!
He needs a red hi-vis jacket
Should be a TS hiviz for sale as merch - missing a fortune
I’m imagining the researchers pausing for moment when Tom asked what the purpose of this was and they had to fight the urge to say “because explosions are cool”
"We're definitely not planning something malicious."
“Because we haven’t had a decent pay rise...”
"It's about sending a message."
@Borrego a Yudando Nah. The auto industry. Millions of deadly several-tons things with the power of several hundred horses that nobody bats an eye about whereever they are. THOSE are dangerous.
Their actual answer was perfectly fine: SCIENCE!
3:17 Tom: “What’s the use for this?”
Researchers: “Uh, because *it’s rad?”*
"We'd like to look at an explosion in slow motion"
The funding board: "say no more fam"
maybe they also **deg** it.
The researcher's last word on the subject is "cool, innit?"
When the researchers are excited by their work, that's when you get the most results.
That's science
@@pepperypeppers2755 "Remember kids, the only difference between screwing around and science is writing it down." - Alex Jason/Adam Savage Edit: I got the quote slightly wrong. Fixed.
Tom is the only person that makes a saftey vest look like reasonable casual wear.
We're just so used to it now that it's like him adorning a red t-shirt.
I think a lot of this has to do with how the color of the reflective strips match the color of the hoodie.
...whereas colinfurze is the only person that makes a casual tie look like reasonable safety equipment :D
ever been in an English pub around lunch time?
Is anyone bothered that it was crooked?
The actual data from this test didn't make it into the video (it's just a LOT of numbers), but there's a paper in the description for those so inclined! And this week's pinned-comment plug: the Technical Difficulties are back! A new season of four adventures from me, Chris, Gary and Matt over at th-cam.com/users/techdif - one every Thursday.
s
3 days ago, how?
weewoo tom
s
Pre-upload
The best of these videos are when the chaperone is as giddy and excited about the tech as Tom is.
There nothing better than a excited adult. May be because most are pretty boring and unexcitable.
@@DavidKnowles0and perhaps also because we have been conditioned by society not to show excitement even if we feel it 🥲
@@turtlepenguinXkizuna absolutely and it's such a loss for every one of us. Let's all get giddy about things we love!
@@turtlepenguinXkizuna Not to show excitement? Ever been to a football match? Sometimes there's way too much excitement.
That's *Dr* Chaperone to you... ;-)
If you go to 5:06 and use the . button to go frame by frame, you can see that the ground lights up 1 frame before the explosion is visible. This is because the camera scans in "lines" of pixels top to bottom. When it was at the explosive material, it had not gone off yet, by the time it got to the ground, it had.
thank you for the dot button tip!
@@richcolour You can also use the comma to go back a frame.
Equally interesting is the shape and location of the light. It almost looks masked off somehow.
Thanks for the tip on how waste even more time on you tube. Now I have watch all the slowmo guys videos again.
Wow, cool find! Thanks!
5:51 interesting to see the shockwave resonates the dust under the table. Wonder what impact this has on the signals within the data cables which run out from here and if a deflector would be beneficial
The dust is kicked up but I see no resonance. The shockwave through the air will hit the striped screen and bounce back. This could cause the appearance of a interference-pattern. I think the dust kicks up because the barrel restricts the flow of air underneath it. Also, the barrel's 4 wheels are pushed into the dirt, so they cause some disturbance too.
Nerds.
@@DreadX10 what's the differnece?
As the wave passes through the cable linearly at any one point, as a radio wave would, you could likely use conventional noise removal techniques.
@@user-op8fg3ny3j Quite literally everything.
Oh hey, this is something I actually do active research and development on! We’ve actually gotten pretty good at making computer simulations of these kind of explosions using multi-phase physics models. The Kingery-Bulmash model that Tom mentioned is still used in places, but it’s ridiculously simple compared to real simulations.
I've always been curious: how do you wrangle the positive feedback from heating? Do you let it run wild but put a cap on transport rates, or what's the strategy?
That's so cool! Are any of those simulators publicly available?
And here I thought blowing things up industrially was fun. I really want to get into the research/engineering side of things, but that generally requires more education than I've got/am willing and able to acquire at this point.
@@cdavie5 That's such a good question. If you're modeling the chemistry, then the heat production will be limited by how much reactant is available. So like you say, it's limited by transport, either how fast fresh reactant can get in by diffusion, or how fast the heat can spread by thermal conductivity. Or in the case of a detonation, it's limited by the how fast the shock wave can travel and how much energy can be released by the material.
In my case, we don't really model the detailed chemistry because it'd be so expensive. We have an equation of state for the energetic material, which controls the amount of energy and temperature that's released.
@@Krazylegz42 got any recommended reading for equation of state models? I’ve done some reading on impact constituent models like Johnson cook, but I had trouble finding a primer of shock EOS
I love it when a sciency person says, "We don't know what we don't know", it's both so true, and so honest.
Or sometimes just "we don't know."
It actually kind of is a sign of a good sciency person that they WILL say that.
If you don't know what you don't know, does that involve research research?
Unknown unknows are an important concepr in theory of knowledge as it requires different approaches and heuristics.
@@dmarsub Just ask Donald Rumsfeld. Unknown unknowns ruined his life.
Sam was my lecturer in the blast protection module of my civil engineering degree. Fascinating subject and a great teacher.
Sam popping off and getting the limelight he absolutely deserves
Always amazes me that a scientist 100 years ago can think up theories that we can only test today.
Kinda same nowdays, there are a lot of theories that we have no way to prove but who knows, maybe 100 years later someone will prove or disprove them (string theory etc)
When you have people who dedicate their lives for their dreams, they excel. The entire lives of these scientists were composed of constant studying and creativity. Like Isaac Newton, he studied daily. And with his creativity, he began applying his knowledge to many other fields.
And if those scientists were still alive I'd like to believe they'd be very smug about it.
@@titan5064 idk if string theory will ever be falsifiable, it's just so out there, and they always say that they'll get evidence in the next decade.
then again, we were able to disprove theories that explained dark energy as instead the universe existing on a 5d shape via closely measuring gravitational waves, so maybe we'll be able to someday.
@@Colopty Who wouldn't be? It would be amazing to be that correct that far back.
Nothing a scientist loves more than someone who obviously appreciates their work, you could see how chuffed he was at Tom's genuine amazement.
It’s amazing how many things there are that people had theories about how they worked 100+ years ago, and yet we’re either no closer to actually knowing or we’re JUST getting into it, like this
Just imagine life 100 years from now
I love how jealous Tom looked when he was told the camera recorded a quarter million FPS. Like, that was just as much a highlight for him as the explosion
If ever there was a Tom Scott video to collab with Slow Mo Guys...
And we run that camera all the way up to 10 million frames per second 😅
@@Trit0n1 Holy crap! How many tenths of a second can you put in buffer at that rate?
@@marvindebot3264 We can only put 128 frames in buffer.
@@Trit0n1 I thought it would be small. that's an incredible framerate. So you get about a nanosecond of footage?
tom scott is THE cool guy that doesn't look at explosions
He is HIM
He blows things up and then walks away
He just listens
He strides forward in his dimond covered boots
He does, however, give a cheesy grin to camera!
The last two utterances in this video encapsulate why I watch Tom Scott videos: his genuine desire not only to allow people passionate about interesting things to explain them, but also to *get excited along with them*.
Tom geeks out about learning new things, which lets the people he's interviewing geek out about their subject matter.
Tom, this has been a game changer video. I cannot understate how much this has solidified what I want to do as a career. I’m currently working on a forensic science degree and have been thinking of doing something like explosives and/or fires. Yes, I do definitely want to do this. This blew my mind up with it! Thank you!!
you could say, mind blown?
An explosive epiphany!
Cool, good luck!
This video is pyrotechnically correct. The best kind of correct.
Wish I had this video about 4 months ago, my dissertation was about simulating fires and part of the background was saying why we couldn't/ it's so difficult to simulate explosions! Nice video once again 👌
"Remember kids, the only difference between screwing around and science is writing it down."
Last year I worked for a MACV-SOG/SEAL veteran, who works for the Department of Defense. He’s been mapping the surface areas of expanding blast waves as an engineer. I learned new applications of Brownian Motion from him.
damn, MACV-SOG and an engineer, that’s a hell of a career
@@jonathanpfeffer3716despite the stereotype about soldiers being stupid you don’t become special forces if you’re dumb. Most of those guys could go get a college degree and be successful out of the military.
The reason they stay in and get shot at is because they want to.
That feeling when you're just graduating from Sheffield and you didn't even realise that your uni was doing thing.
I can't be the only one who was kinda expecting to hear Slow mo guys music at 5:17
No-one knows how explosions work (yet), but Tom Scott will be there to tell us, for sure
The multiscale/multiphysics and tiny timesteps required to simulate this stuff is so complicated. Data like this is used during validation and uncertainty quantification for models.
Ooh! The HSE labs :) fascinating place. Built on top of RAF Harpur Hill, in its day it was the second largest munitions dump in the country - a honeycomb of concrete bunkers built in a disused quarry before being backfilled to look like a hill again. Also one of the locations where the MOD dismantled and studied the German vengeance weapons of WW2...
Shhhh...
Have you got any history about the area? This site is on top of hte hill and not near the tunnels. But we are very interested in the site and its history and always lookin for more information.
The dust coming off the large concrete pad is really interesting - shows how much energy is in even that 100g of explosive
0.0000001kilotons.
or 0.000000005 Hiroshimas.
Actually this only works if the explosive is tnt but I can't be bothered.
I get that its built for different forces and that, but its quite funny seeing this box delicately lowered to the ground by the forklift before it's blown up by an explosive
Like protecting a perpetrator's head as they get in the police car, after being tazered and beaten.
We had this problem when designing our detonation rig at the University of Southampton. We needed a way to collect experimental data that wasn't just qualitative, and it was incredibly difficult to find a sensor that we could expose directly to the detonation on the inside of a detonation chamber that could read data fast enough, resist the 3,000 Kelvin instantaneous temperature, and sustain anywhere from vacuum to 60 atmospheres of pressure. Using strain gauges is a cool idea to look at detonation wave speeds, but I don't see how they can read static pressure and temperature with time
4:54
"We kinda don't know what we don't know"
-Mr Pioneer the engineer, 2023
It's amazing that we can understand so much about nature, yet be eluded by such basic things. Another example of this is the dynamics of a 2 wheeled vehicle such as a bicycle or motorcycle.
Humans 100% understand every aspect of how a bicycle works. Coming from a bike shop mechanic.
You should publish a paper describing how the wheels rotating increases upright stability then. It would be guaranteed to make waves.
@@brennancork Right. My bicycle has never done anything strange. Even when crashing into a BMW.
@@flinxsl already been done many times, my wave would be minuscule in magnitude and duration
@@brennancork I just looked it up and it has not been done. It looks like theory is that the moving wheel creates a gyroscopic effect which keeps it upright but they did an experiment to eliminate the gyroscopic effect and it it still remained stable soooooo
1:07 Really should be called the Senior Lecturer in Big Booms
It's amazing how the black and white slow mo looks exactly like those still frames of the Trinity explosion, which was 186,000 times bigger.
The "kick vs push" question is similar to the "what is a dot?" one. if you look far enough, everything is a dot (just like everything is a kick if you speed it fast enough). It becomes interesting if you zoom in the other direction. :)
Don't mind me, just stealing this explanation to use in the future ;-)
Interestingly enough this is a similar problem that we have in lightning research, in the sense that you cannot get close to the object you are studying. So maybe their research can also benefit lightning researchers in their efforts!
I thought rocket induced lightning has been a thing for many years. Are you talking about the high altitude stuff?
@@chakflying1i think they mean the fact that you can't put sensitive sensors right next to lightning bolts because they'll get fried
I suspect that the data gathered can be used to suppress or enhance explosions in the future. It is ever so. It’s also a constant that the researchers will present what the think sells the best.
Now do a video of you going through Heathrow security. I once visited an explosion test site and then had a very interesting discussion at the Airport…
I'm a pyrotech, we put all clothing worn during blasting in sealed bags in checked luggage. Nothing (even boots) that was near explosives goes on you or in your carry-on. I pass the swab testing 95% of the time and we have ID to cover the times we don't.
The access statistics of the paper show clearly when tom uploaded.
At 05:13 : Tom's got the face of someone who's going to spend the next 12 hours searching for the right frame 😅. Fortunately, it didn't take that long.
if I am not mistaken it's taught in the military to stay clear of walls during explosions exactly because of this double pressure from the blast and the bounce.
Makes sense
1:00 ah yes the Tom Scott red shirt flag has been raised to alert everyone of his presence
Damn, filmed at about 250,000 fps, giving The Slow Mo Guys a run for their money.
5:10
These researchers have a camera that does 10,000,000 FPS
@@longofire236 Damn that’s one strong camera
@@rocksteeltitan That's what millions in research funding pay for. Powerful research instruments and talents (of course).
This looks like a job for the Slo Mo Guys 😁
Yooooo....mixing in some "Slow Mo Guys"-like stuff into science stuff from Tom Scott...I'm loving it!
That’s what I’m working on currently for my masters. It’s a difficult line of research due to how much of it isn’t public knowledge.
That was absolutely fascinating and possibly the most interesting vid I’ve watched this year.
I feel like, as a result of so many encounters with so many different phenomena, Tom has begun to intuit some of the observations these scientists are making. A sort of "wait, wait, don't tell me! Let me see if I've got this right!" thing.
He probably does his research, too.
Tom Scott is the scientist whisperer.
It's just common sense if you're vaguely scientifically minded.
Great video Tom - but please for goodness sake get the slow mo guys there with a phantom camera! They did an amazing video with an explosion where you could clearly see the shockwave, initial blast wave and negative wave pressure.
Congratulations on 6m subs Tom, still going strong after all this time ❤.
2:15 Kinda cool to see 3D printed tooling used in an application like this! With heat set threaded inserts even
FASCINATING stuff, the possibilities are astounding of this kind of understanding
That's true! I'm an FX artist and the start of the simulation is pretty weird, it looks cool because it's the magic of the cinema, it's based on real life but the actual application is very weird indeed lol
That is a VERY satisfying explosion noise
Reminds me of the shock waves reflected by the ground during air bursts of nuclear weapons (albeit on a much larger scale), which then interfere constructively and largely increase the force of the blast.
These dudes blow things up in slow motion for a living.
That's definitely cool.
I could easily observe an explosion up close in detail. At least once.
It almost looks like a fractal pattern when it’s exploding, as if it’s pushing in a set path.
"Cool, isn't it?" Clearly someone who very much enjoys his job.
i genuinely feel like insights in this research can be changing the future of humanity, control over the force exerted at that precise a scale lets us make new engines, reactors, materials
It can also help us make more destructive explosives, they kinda swept that little detail under the rug.
5:10
Footage shown is just an MRI of Tom Scott while watching/hearing the explosion.
Cool part is, it's a perfect model of the explosion itself.
Once scientists figure out how explosions work, the next thing to tackle will be cranial explosions.
Wow! Look at that HUGE lego at 4:35!
I like that the guys setting up the tennis ball sized piece of c4 are wearing earmuffs and safety glasses.
And idiotic hi-viz, none of which will be of any use at all if the damn thing decides to go off! Especially the hi-viz.
Tom trying out being one of the slow mo guys
This little thing looked way more powerful than what we got for the explosion in Oppenheimer.
Oppenheimer should have used the actual trinity footage remastered
Have you ever covered how factories stitch books with thread? I'm trying to get my brain around it and just can't. I haven't found any videos that go into how it works, at least not as well or detailed or complete as some do for fabric sewing.
@Dave Rosser It might be an older method than you are looking for, but Adam Savage just recently did some videos on bookbinding at a bookbinding museum with historical equipment. The person explaining things to Adam went into detail about how the equipment sewed the signatures.
Look for medieval bookbinding videos, one just popped up on my recommended vids last week. I would imagine factories do it the same way just quicker..
I will say this, as I watched the regular explosion vs 'Hollywood' explosion a few hours ago(also you on fire), seeing it again in the beginning, you are probably the only person cheesing a smile the whole time, and it is glorious. 🥰
5:05 if you pause frame by frame you can see that the light from the explosion shows up on the ground faster than the camera can catch the light emitting from the actual explosive.
rolling shutter?
@@WyattWinters Yip, that footage was filmed with Toms little camera not a high speed one
I need Tom Scott in my life. If I have to live vicariously, then he is the best route to travel. I have lost track of how many deep dives, and google earth expeditions i have done, because I wanted to know more about one of this snippets of fascinating info. Grammar is a goal, never for this me, myself, and I, to attain.
Another great Tom Scott video!
You couldn't have watched it in the1min it's been uploaded by now 😄
This is the most Slow Mo Guys video Tom Scott has ever done.
Dr Sam seems like a fun guy to chat to about explosions
Please tell that to my students
That was fascinating. Thanks to the reasearch team for showing us
Can we all appreciate how much a wonder nerd Tom is. He is all of us there
Congratulations on the 6 million subscribers.. 5.99 .. almost there
This is the kind of thing I thought people would have figured out by now. It’s crazy how much we still don’t know about the world
It’s that classic thing of asking, “yes, but why…?” over and over again… get closer, get smaller, see things in more depth… answer the ‘Why?’ at one scale and then ask, “But what happens at the molecular scale?”
We've been blowing things up for a long time; it's reasonable to think that.
But anything chaotic is really hard to model. We don't really understand turbulent flow such as water in a stream either.
It's crazy?
You don't know what "crazy" really means.
Now *THIS* is the kind of science I can get behind!
It's interesting how a slow-mo real explosion looks a lot like a movie one :-) turns out they were really onto something, haha!
I used to work with a group of people who designed warheads, like HB 876 (I knew the guy who suggested the dimpled case) and BL 755. When I was paying attention they were modelling self forging fragments, which involved modelling the detonation of explosives and the forming of the metal plate that they were in contact with. Their experimental results corresponded very well with their model. So I'm surprised to hear, nearly 30 years later, that they didn't understand the explosion. It seemed like they understood it really well. This short range blast was actually far outside of their area of interest, by the time the plate started to move the explosion was discarded from calculations and the metal was just coasting to its final configuration (teardrop shape, pointy end first) and had already reached its maximum velocity.
All a warhead designer is interested in is the final effect, not the minutiae of the initial detonation. Final effect can be determined by the simple expedient of explosive testing, rather than by mathematical calculation. The explosive testing is going to happen anyway, so you cut to the chase and get a bigger bang for your buck.
I just looked up the HB 876. The dimpling reminds me a little of shape charge warheads. Did they invert and become penetrators?
@@JarrodFrates Exactly. HB 876 is an area denial mine. So it is dropped in a swarm and they are influence and time fuzed. If you look up JP233 or HADES you will see the dispensers. The mines have springs on the side which stand them up. If something drives over them , or knocks them over, they detonate. If you try to clear them with a dozer they are cunningly designed to tip towards the blade and fire the main EFP through the dozer. At random times they detonate and blast out a ring of small EFPs which 'interfere' with clearance efforts. If I remember right they are dangerous to several hundred meters. In JP233 they are dispensed around SG357 cratering munitions, so they crater a runway and surround the craters with mines that no sensible person would approach. In testing in the US the pilot missed the target area and dropped them in grass, they had to burn the grass then use three teams of snipers to detonate the mines from a safe distance.
I thought this was an old episode replayed. Thank you and a have a great day.
Cool guys look away from explosions, cooler guys look AT the explosions.
The coolest guys study them and the driving force behind them
The coolest guys look INTO explosions.
@@Jayfive276so like chemistry?
Coolest guys die in the explosions
Thanks Tom, that was brilliant, my coffee nearly went cold. Cheers
I turned the volume up and started paying more attention at "...could save lives" and it immediately made me feel like a big utilitarian nerd instead of a just a vague general nerd.
tom i want you to know that i love your podcast lateral and will be absolutely crushed if it ever goes away, mentioning it here, because i didn't know it existed until recently.
0:34 how did you not say "or lots of smaller problems"
"We don't know what we don't know" - Sun Tzu, The Art of War
it is a good day when tom posts
"A whacking big steel plate..." love it!
If you film yourself being very, very close to an explosion for TikTok, you’ll soon be everywhere.
Good one
Everywhere around the explosion site, that is.
did load of work on that site years ago where they were testing new gas pipeline systems. weeks wiring up strain gages and thousands of meters of cables back to the control building.
Imagine meassuring blasts. That job must be a blast
Imagine measuring *explosions*, that job must be a blast. FTFY
Congratulations to Tom for reaching 6 million subscribers 🎉
I bet this'll be a banger.
Congrats on hitting 6 million subs 🎉🎉
how awesome would it be to say you study explosions for a living
If only it would make me a hit at parties... 😮💨
It does make sense why it would be so "difficult" to measure and understand a concept so important to nuclear weapons.
This team needs to hit up the slow mo guys
1:37
Ohhh because of signal transduction.
Like when science hits Tom Scott the right way,
my notifications make a ringing sound.
that's cool to see! thanks tom, nice slow motion explosion up close.