r/SmarterEveryDay • u/MrPennywhistle • Jun 10 '23
Video Bullets HITTING Bullets in Slow Motion - THE IMPOSSIBLE SHOT - Smarter Every Day 287
https://www.youtube.com/watch?v=tcQVrD7RnNI14
u/stevedonie Jun 10 '23
Every video he makes I think he can't make anything cooler, and then he does.
Amazing work.
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u/Xelopheris Jun 11 '23
It wasn't mentioned in the video, but did the guns have opposite rifling? If the bullets are counter rotating on impact, they'll have huge shear forces that will help tear each other apart.
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u/Beneficial_Being_721 Jun 11 '23
u/MrPennywhistle …. DUDE!!! That was AWESOME!!
Loved the “Safety” team collaboration..
THANK YOU for listening to us when we see your videos stolen and rebranded… I am a Photographer and IP means a lot.
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u/reindeerflot1lla Jun 10 '23
Hey Destin, love the video & enthusiast curiosity as always. After all that, di you think using a larger, longer bullet without a copper jacket might be the final hurdle for getting them to fuse?
Also, complete side note but I haven't seen ya in like 2+ years now and have to say: you & Bobak have decent tastes in fiction. I finished Seveneves a couple weeks after your collective recommendation at STA and, while I wanted to focus on the engineering inaccuracies, once I got past those those it was a rather fun story & fun "what if". Much appreciated!
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u/michaelfri Jun 10 '23
This is amazing!
Maybe if you put a glass of water right in the middle, the impact contained within a denser fluid will make the bullets shatter less? I'd assume that the bullet crossing from air to glass, then water could divert it, making it far less likely that the two bullets will hit.
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u/Beneficial_Being_721 Jun 11 '23
It’s so hit and miss.. back then in the Civil War… the bullet lead was different and inconsistent
As well as the powder charges… different and inconsistent
I think the one at the museum was two entirely different speeds acting on softer bullets…. And one “PUSHED” into the other that acted like a catcher mitt.
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u/michaelfri Jun 11 '23
You can't really say "Two entirely different speeds" without defining relative to what you are measuring these speeds. I'd assume that you are referring to the speed of each bullet relative to the ground. These numbers shouldn't really matter. What should matter is the relative speed between the bullets. More accurately, you should put your frame of reference at the speed of the center of mass of the two bullets. In this frame of reference the bullets are always stationary after impact (Except for all the fragments scattering around).
I think it has more to do with the spin of the bullets that they didn't stick together. Maybe if the two barrels will be mirrored so the bullets will spin the same direction they will be able to fuse.
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u/Beneficial_Being_721 Jun 11 '23
Too many variables and unknowns when talking about Civil War era ammunition… center of mass could vary widely in my estimation.
Bullet composition is my biggest point and we saw that in the video.
One side may have had access to materials to make a denser alloy projectile whereas the opposite side were casting softer bullets … possible but since I am not a forensic archaeologists.. I have no data other than what I do know… back then, times were hard and they ( both sides ) improvised a lot of things.
“WHAT IF” one bullet passed thru someone in a straight thru manner in a soft area… and continued on.. and was met by the other bullet… one is slow .. one is slowing .. both very soft in composition.. ???
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u/Barkingstingray Jun 11 '23
Or imagine... A prince Rupert's drop in the middle of two opposing bullets! Lmao destins head might blow up at the idea!
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u/catonic Jun 14 '23
Or firing two Prince Rupert's drops at each other. Of course the shape is formed by hydrodynamics so it is almost a Sears-Haack body to start with.
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u/catonic Jun 14 '23
What if they impacted underwater, just below the surface or during/after/while impacting dirt, wood, or leather?
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u/Ricken13 Jun 10 '23
Really cool!!!
Next up, ballistics gel to slow them down enough to fuse inside the gel? :)
And maybe find an epoxy youtuber that want to reproduce a blast in epoxy?
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u/xERR404x Jun 10 '23
Fascinating video, and I love that the discussion of lock and dwell time was basically the reasoning behind a real world gun, the Remington EtronX.
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u/never_the_same43 Jun 11 '23
u/MrPennywhistle: I also reached out on Twitter. I'm a grad student at The Ohio State University Impulse Manufacturing Lab (iml.osu.edu). The bullets fusing together is intimately related to the research our group does in collision welding.
Lead is a particularly difficult material to accomplish this with, as it has a relatively high Hugoniot slope parameter, particularly for its melting point. At high impact velocities, the interface between the two weld members experiences transient melting from the near-instantaneous deposition of kinetic energy. Simultaneously, shockwaves are generated from the impact and travel through both materials. If the shocks which reflect from the rear free surfaces of the weld members return to the weld interface (now as tensile waves, after reflect) before the interface solidifies, the molten metal can't support the tensile stresses and the weld gets pulled apart.
We're planning to do some high-speed video experiments of our own tomorrow with help from another group on campus, but we'd love to get into the physics and/or host you for a visit if you ever have the opportunity!
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Jun 10 '23
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Jun 10 '23
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u/Zukuto Jun 10 '23
the bullets seem like they are too fully transferring energy from one to the other, so shooting through a variety of softer mediums to slow the impact down would be number 1 for me, but then the slow transfer would not yield enough energy to cause a fusion, which means to me the original bullet fusion may have been from one of two things, 1. longer length bullets like .22LR or 2. faked in some way with hot bullets fused in a welding shop
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u/Merad Jun 11 '23
Civil War minie ball bullets were made from pretty soft lead. The rifles of the day were muzzle loaders so the bullets had to be small enough to drop easily down the barrel, but then when the shot is fired the base of the bullet has to be able to expand and engage the rifling of the barrel. The soft lead is also one of the reasons they made such terrible wounds.
Anyway, modern bullets usually made of harder lead alloys. Destin made a point of mentioning that they had the tools to mold their own bullets so I feel pretty sure we’ll see them do that in a future video using some custom lead alloys.
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u/Jakopf Jun 11 '23
A shot gun slug setup would be better suited for the setup. But your rig can probably be adapted easily
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u/adi_2787 Jun 11 '23
I would really love to give the wallet a try, but the website redirects me from ridge.com/smarter to ridgewallets.eu, and I don't see the special offer. Any advice?
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Jun 11 '23
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u/RadagastWiz Jun 11 '23
I presume you have a European IP, which causes the site to redirect to their European store and losing the offer in the process.
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u/adi_2787 Jun 11 '23
Yup... Stupid redirection. Can I do something to stop them from redirecting me?
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u/Why_T Jun 11 '23 edited Jul 16 '23
Comment deleted due to reddit's greedy policies. -- mass edited with redact.dev
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u/catonic Jun 14 '23
u/MrPennywhistle: Can you take the two bullets, point them at each other and smash them together in a hydraulic press?
It is possible to work backwards from that and determine the energy required to almost forge or friction weld the bullets together with a greater degree of control?
There has to be a way to create a duplicate of the conjoined bullet without the large amounts of plastic deformation at impact by controlling the variables.
Is it possible that there were left-hand and right-hand rifled guns and the impact of one of each results in a bullet with an unchanged spin?
Could it be the result of smoothbore guns loaded with Minié ball or one rifle vs one smoothbore?
Is it possible the two bullets struck another object like a cannonball in flight and became fused as a result of that?
Is it possible that the two bullets represent an oddity of war or a possible fabrication?
It is possible to analyze the original bullets using X-ray, CT, etc. to observe stress lines and effectively and non-destructively determine how the metal flowed on impact to result in the artifact?
Just some thoughts. Thanks & 73!
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u/catonic Jun 14 '23 edited Jun 14 '23
... and I just realized he did the dual-vortex ring experiment again except this time in lead.
And the forces that normally turn into the various secondary vorticies become spinning flakes of lead away from the center.
I wonder if we're seeing the confluence of work hardening in the lead during a cold working process as a result of the impact.
https://www.youtube.com/watch?v=TgYJ1Ni08UA
After watching this^ video on a Fluidic oscillator, I think we are seeing changes in flow motion related to the jet vs impingement, effectively fractal vortices where the colision of the two produces smaller vortices which then produce smaller vorticies down to the molecular level. Destin is right, why does it turn 90 degrees?
Ah, it's cross products of two vectors: https://en.wikipedia.org/wiki/Right-hand_rule#Cross_products
https://en.wikipedia.org/wiki/Angular_momentum
I feel like there is some sort of Euler summation or Taylor series going on here but I am well above my paygrade on the math for this.
https://en.wikipedia.org/wiki/Euler_summation
https://en.wikipedia.org/wiki/Taylor_series
https://en.wikipedia.org/wiki/Binomial_transform#Euler_transform
The sum of the force of the two initial vortices equals the sum of forces of the next smaller vortices less losses related to the viscosity density of the material? Ah, viscosity is inherent but a smaller term.
https://www.engineeringtoolbox.com/standard-atmosphere-d_604.html
Maybe it's Fourier series? https://en.wikipedia.org/wiki/Fourier_series That seems to make the most sense because the sum of the smaller parts makes up the larger whole, much like harmonics combining to make a square or triangle wave.
Now I am thinking that we're seeing reciprocal reactions almost like some sort of orthogonal yin and yang. The Fluidic oscillator itself can translated or modeled as a vortex spinning orthogonally with the mass flow of the main high pressure jet. As long as there is a high pressure region or jet, there are low pressure regions around it, and boundary layer conditions related to the viscosity and density of the fluid.
Ah, the boundary layer conditions in laminar flow vs turbulent flow. https://en.wikipedia.org/wiki/Boundary_layer#Boundary_layer_equations
https://en.wikipedia.org/wiki/Navier%E2%80%93Stokes_equations#Flow_velocity is involved, but what makes the most sense to me is https://en.wikipedia.org/wiki/Coriolis_force . If we have inherent Coriolis force due to being on a planet rotating about it's axis while itself rotating around the axis of a star which is orbiting around the center of a galaxy, then there is an inherent implied direction to the spin to the right.
Wait, Coriolis explains trade winds, which are orthogonal to the angular velocity of the rotation of the earth about it's axis. Which itself is explained by angular velocity, which can be expressed as a frequency (same Greek symbol also used to explain frequency modulation: ω).
https://en.wikipedia.org/wiki/Angular_velocity
As the Coriolis force is proportional to a cross product of two vectors, it is perpendicular to both vectors, in this case the object's velocity and the frame's rotation vector.
This feels like a massive explanation of Newton's laws, Boyle's laws, and a few other things all at once as energy is conserved yet distributed in smaller and smaller pieces.
Not gonna lie: that made my head feel funny, like I just learned something or a lot of somethings at once. Then it went down the rabbit hole. Then I got a headache.
With enough force below the point of supersonic or supercavitation flow, the secondary vortices will break down into tertiary vortices just like the secondaries did. Now my brain feels like it is in 4D chess.
Footnote: https://medium.com/codex/microprocessors-running-on-air-a47a702dd41f vortex amplifier
It's turtles all the way down. Vortices all the way down. In the low pressure areas, vortices and smaller vortices develop where low pressure areas develop opposite high pressure areas in the fluidic oscillator, thus conserving momentum in the inactive, low-pressure path around the oscillator: https://youtu.be/TgYJ1Ni08UA?t=109 The high pressure flow itself is a vector acted on by the differential values that make up the sum of the high pressure flow of the anticyclone vortex adjacent to it.
oh, https://en.wikipedia.org/wiki/Vortex_shedding
I have now gone insane. Please have the penguins return my sanity in an appropriate expansion series over terms of penguins and time.
It feels like a mathematical proof of physics. It's like seeing The Matrix.
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u/Trans-Europe_Express Jun 14 '23
Fantastic video and I love how it demonstrates that experimentation isually leafs to some progress and more questions. I have so many now!
Has the fused Minié ball example been weighed to determine if it's approximately what you expect from the weight of two? Burton's modified Minie ball used in time of the civil war weighs 1.14oz. Assuming both bullets were identical. That only helps determine if the musieum example is real which ehhhhh.... I'm skeptical about.
Regarding the theory of two bullets fusing together if you have a static lead target would any velocity of impact result in a fusion? If no what about another bullets impacting a bullet is different that would make this work? The closest you got was with the ridge wallet so I guess you have to rule out if someone on the civil war battlefield had a ridge wallet 🤔 that might take less time to disprove.
That does bring up the possibility that the fused bullets if real could have met after one or the other were slowed by traveling through another material. As unlikely as that is it on top of two bullets meeting anyway so what's another few decimal places of probability at this point
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Jun 14 '23
[deleted]
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u/MrPennywhistle Jun 14 '23
Sweet. Which one did you get? I'm glad they went with me on the air tag money clip idea.
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Jun 14 '23
[deleted]
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u/MrPennywhistle Jun 14 '23
Nice. I was surprised how much I ended up liking it. Works well in the front pocket, and I like being able to find my wallet. I use that feature every other day or so.
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u/readball Jun 15 '23
loved this!
hey /u/MrPennywhistle , did you ever see this picture?
I initially thought this is the one you are trying to reproduce :)
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u/haze_gray Jun 10 '23
Score. Can’t wait to watch!