The weirdness also implies that the material is anisotropic; that is, the properties are different when applied in different directions. For example, the front face of the shield dissipates energy from impacts without rebounding. Some writers explain that the vibranium stores this energy like a battery and releases it when the edges strike things. This explains some of the more ridiculous bank shots Cap manages, since the shield actually can use this stored energy to have a higher velocity after the bounce than before it.
Agreed, especially considering that bullets do not ricochet off Cap's shield, unlike Kyle said. (See Captain America: The First Avenger, shield introduction scene for example.) On the other hand, this presents a problem when using the shield's edge to beat and strike targets. I.e. why doesn't the shield bounce in reaction like the Absent-minded Professor's Flubber shoes? The intensity could be controlled by arguing that energy can only be released from the shield edge in certain amounts. However, we do not see any bounce or extra energy release when Cap uses his shield to beat up his enemies, including Iron Man.
At the time of my comment: Kyle and the guys are busy with the Muskwatch eps (historic Falcon Heavy reusable main rockets and booster launch) and separate Because Science content to release content that coincides with the BP red carpet world premiere. Would've been a good tie-up though!
What about that scene in The Winter Soldier where he jumps out the elevator and lands on the shield? Wouldn't he bounce back up instead of staying on the ground like he does in the movie?
Because he is spread on the more wide part of the shield and not the edge. Remember that you can increase force by refining the impact. Like A hammer bs a hammer and nail. The nail is at a point and the point refine the impact to a singular point and thus creates more force. You ever see the should bouce as much when the shile drops on it's almost flattened side? No. It bounces a little, but because the force is spread, it distribues outward rather than back inward. I am rather bad at explaining so I hope I explained right.
Scott Sommer I think is trying to say that due to the outer edge of the shield being significantly smaller than the front of the shield it would bounce less and work more like a hammer hitting the ground. What you’re assuming is that there’s no second impact (albeit small) in falls like that, either way it’s why the front of the shield absorbs impacts as it does. The rings compress on one another on a very small scale and absorb the shock of consistent force dispersing it around the shield in a shock wave type manner/widening the force of the impact and especially in terms of beam weapons would disperse the energy to widen the blast so it’s more like a strong wind going by (for one close to the size of the shield’s large frontal surface area). Of course it has been shown to break inside Marvel Comics, but it’s from EXTREME amounts of force that overcome the shields elasticity.
Same thing for when Ag Carter shoots at him and the bullets simply hit the shield and drop... no bounce occurs... there are other scenes that has the same properties.. it only changes when its been thrown... I would say "magic" or an outer ring made of diff metal..
What about all those god blast impact the shield could block? The only explanation is magic. When the writers made up the throw attack, they completely forgot the shield wasn't able to do it at all (no matter how hard Capt might throw it, as soon as it touches the target, all energy would be gone and shield drops. The target would receive no impact what so ever).
If it was just the shield hitting the ground it would probably bounce but something to consider is that PEOPLE don't bounce and so landing on top of the shield would transfer the kinetic energy to your body and you'd still hit the ground like like normal
There is on more thing to consider, and that is the material that the thing bounces OFF of since some energy always has to end up there. Now, if it's a sturdy wall that's probably negligible, but the 'physics' behind the shield actually start not make sense anymore when bouncing off of people. When that happens not only do you definitely deposit energy in the body by deformation, but also by transferring kinetic energy which ends in that person flying through the air. Since the shield apparently never loses it's kinetic energy though, energy conservation is probably violated (or conversation of momentum, alternatively, though in a situation like this they're basically the same thing if you don't want to consider how the shield deposits energy in the form of heat and/or deformation in the person it's hitting.)
Wow... that is a surprisingly intellectual insight... I've given some thought to the subject since watching Civil War, and the only solution to the conservation of energy problem I can come with is that the shield hits the rebounding surface so hard that it causes the surface atoms to fuse, releasing energy. But that's just my opinion, and I apologize if it offends anyone.
I was just about to put a post on the same subject! Another thing that I find physics breaking about his shield is that bullets don't ricochet off it it. They just drop (visual evidence is in Captain America 1 where he gets the shield for the first time). In that situation, should the elastic metal property apply to the bullets as well? They should have lost a lot of their kinetic potential to the shield, but they definitely should also have ricocheted off of it at a much greater velocity than just falling straight to the ground. For some reason the shield absorbed all of the energy from the bullet, didn't return any energy to the bullet, and didn't let any of the energy pass through the shield and into Cap's arm. By all means if the shield works the way that Kyle explained it, then even if it was designed to mostly bounce along it's sides, frontal attacks would still have some elasticity and cause forces to act and deal with the transfer of energy.
Huh... never thought of that before... although, if the bullets ricocheted with higher ricochet velocity than incoming velocity, wouldn't that violate conservation of energy?
Hedshodd - the one thing mentioned but not explicitly understood in Kyle's explanation is the part with edge vs face surface. While, yes, the movies do seem to contradict themselves a bit by bullets ricochetting sometimes and falling flat other times, the idea is HOW, WHEN and WHERE the elastic energy is expressed. The vibranium is fused in with the other metals, not simply laying on it in rings, so my belief has always been that any force/energy towards the shield is temporarily absorbed towards the center point. When released back, people think about it as full angular reflection, but I theorize that it mostly radiates outward from center to the shield edges. So, a lower caliber shot (let's say moving at 200mph or lower) hits the face of the shield, and the kinetic energy of that small thing loses 99% overall of its speed after it transfers into the shield and little reflects back to it. Elasticity action of the shield along vibranium molecule channels bunches it towards the center from almost any angle it is hit, but then radiates most of it back towards the shield's circumference. Essentially most of that bullet's energy transfers out the edges of the shield, and the bullet gets so little back that it barely bounces back. This looks, on the macro level, like the bullet just drops straight down. With a higher caliber bullet (let's say 700mph+) the same concept applies, but at some velocity the shield's elasticity at the contact point reaches a limit. I will call this limit 500mph at a 6mm sq contact point. The math of this is overly simplified, but from 1-500mph at the small contact point, anything loses 99% of its motion by way of kinetic energy transferring in, absorbed towards the center, then radiated out the edges of the shield (to our naked eyes we do not see the air pushed radially out the edges as that kinetic energy reflects out distributed all around it). The remaining 200mph+ of energy experiences significantly less loss, but still some, as vibratory waves crisscross each other for a split second. This amount acts more like standard reflection, and we see this high caliber bullet bounce back. To our naked eye that couldn't track the bullet to start with, we do not realize how much slower the bullet reflects in the opposite direction, but the behavior is now akin to a low caliber shot (like the previous paragraph's example). Now, a previous comment mentioned him dropping from a height onto the ground, on top the shield, but this too is treated similarly. Because it is a curved surface, some of the flat ground isn't contacted, and depending on the height of the fall with gravitational acceleration, he is no where near terminal velocity, i.e. he also isn't past the 500mph:6mm sq tolerance point. Further, more than 6mm is being contacted despite curvature, so even at 12mm sq we already have nearly 1000mph of comparable motion/kinetic force being subject to the -99% treatment. This all means that since the ground isn't going to bounce away like a bullet would, up to 1% of the force that can't properly radiate out the front may radiate out the back into Steve. Also, he doesn't bounce back because the 1% force is not enough to push his mass back up significantly. This, from a short fall, equates to a light tap, and this is on a super soldier, so it is far from dangerous to him. So, in summary, directed momentum mostly radiates out the sides due to elastic channelling to the center then out to the edges at some max tolerance transfer speed (due to vibranium behavior while fused with the unique portions of the metals it is) and turns low caliber into near-stop motion, high caliber into low caliber, and falls into taps. Hope this makes sense as the reasons the movies seem to contradict themselves but aren't truly totally doing so. [EDIT - I must add that with edge impacts at certain angles, the fusion pattern reflects nearly all the directional force back, causing the standard bouncy shield behavior. Certain special angles cause vibrational behavior of all the shield's molecules for the reflection to all radiate out, or be channelled along a point. At those special exact angles, the shield acts nearly the same off a solid wall as it would off a person. At other angles, the shield would probably slice into a person's flesh easier, and at all other angles the energy is distributed all around/mostly out all the edges, so it and other objects essentially come to a halt].
Here's my theory: there are straps on the inside. The cross section of the shield perpendicular to the straps are rigid for the cutting effect. The side parallel to the straps, the rings collapses into each other upon impact ever so slightly creating a bounce back effect. It's why some times that shield seems to flex and other times it's rigid. It all depends on which side of the shield impacts first. Cap learned this in WW2. Falcon is too stupid to learn this.
Vibranium doesn't absorb energy, it reflects nearly all energy expended against it. In an episode of Spider-Man and his amazing friends, Colossus punches a vibranium wall and knocks himself out. This completely explains how Caps shield works.
it absorbs it then returns it, specifically said "absorbs sound waves, and other vibrations and kinetic energy" then returns it, and it makes it the vibration stronger.
Goddamn, i love your show, please never stop doing it, you have so much talent for science and being behind a camera its honestly inspiring, do you ever do a AMA regarding how the show is produced? cuz big props to your crew for making it so smooth
But the real question is why did Howard Stark built a shield and not an armour for cap? 🤔 This is what happened- Howard:" Hey cap we are going to make an armour for you.. (18 hrs later at the facility)- Howard:" Alright gentlemen lets- unknown guy: " Im sorry sir but I think that after giving the supersoldier serum to cap it would be worthless to spend billions on building an armour.. why not just give him a shield that is made up of a steel,vibranium and carbon fibre composite material with a coefficient of restitution close to 1?! Howard: "good thinking ! thanks for the suggestion!" Unknown guy:" Thats my pleasure." Howard stark:" But I must say you have a pretty weird beard!"
I understand that cap is not as smart as Tony or Bruce but you always see him moving once he threw the shield so he just moves to the place the shield comes back
The Shield as CoR so close to 1.0 that its only real limiting factor is the fact it is flying through the air. A follow-up to this video would be one that includes the aerodynamics of a frisbee, and how it relates to Cap's Shield.
Elasticity does not explain how the return force is uni-directional, such as when Thor strikes the shield and is blasted backwards along with the surrounding forest, nor does it explain why the shield can seemingly absorb INFINITE amounts of kinetic energy, such as the iconic scene in Civil War with Iron Man firing his repulsors right at the shield. In addition, if we're talking about elastic transfer, then scenes such as Captain America dropping several stories onto the shield should bounce him back up into the air like a trampoline. Then take into account the sharpness of the edge. At similar visible velocities, the shield can either knock out a human being or embed itself in solid reinforced concrete, or even sheer through various metal armors. Really, this video should have covered the shield being apparently sentient and telepathically linked to its wielder, able to choose the level of harm inflicted at a moment's notice.
Maybe the face of the shield or y plain was specifically made to disperse on coming energy while the inside of the shield on the x plain was made to redirect energy? because you never see the face of cap's shield redirect energy like the edges do.
@ Cole Guidry You mean like in Avengers when Iron Man fires his repulsor beams directly at Cap's shield and he uses it to reflect the beam and cut a swath through the Chitauri? Also, if you re-watch The First Avenger and see the unpainted shield, it looks more like it's made of semi-laminated, concentric rings. While this MIGHT explain its ability to bounce due to contraction and expansion on opposite sides of the rings, it does NOT explain how the same angle and strength of a throw can both knock unconscious a guard and then embed itself into reinforced concrete or steel blast doors.
Well, and coming from a complete Marvel nerd/fanboy, maybe it doesn't follow any laws of physics, hence the quote from ye olde Web-Head in Civil War: "That thing doesn't follow the laws of physics at all!" And Cap responding with "Kid, there's a lot going on that you don't understand." *Obviously* referring to his shield.
Your forgetting one crucial thing. The shield is magnetic. Its shown in 'Age of Ultron' that it's magnetic and that Cap has a device to bring it back to him, so it probably doesn't matter what energy goes where as long as the shield doesn't reach that point of deformity. He just use his force pull (Tony Stark invented SUPER MAGNET) to bring it back to himself or help it on its way. Plus caps new shield referenced in Spider-man Homecoming is probably chocablock full of gadgets as well.
The shield bounces because they wrote it that way. Nice job on the COR physics though. One part of this situation that always annoyed me though is that the extreme durability of his shield also should be deforming the materials he is hitting with it. There should be lots of dents in the materials he is hitting with it and if it hits a material that is too soft, the shield should stick.
I always tink the shield should act like a twisted spring, but in a molecular level, I mean, it can absorb a lot of energy in one side, and release for other side. this work very well with what we see in the movies, it absorb all the impacts with the front, but bounce when hit with the edge.
Kyle Hill FTW, great break down as always... all I'm thinking about is how much Cap is "catching" that shield after throwing. Sorry Mr.America, no handshakes for you...
@5:50 "VIBRANIUM LACED RINGS ...ah you did your research. I remember when they showed the incomplete shield in an Ironman movie and you could see the rings going around it. That's some nice attention to physics on the director's part ! @Nerdist.
They actually show this in the movies: The shield basically throws what hits it back at them. But, it depends on mass. Bullets kinda bounce because cap is heavier than bullets. When he blocks something that weighs more than him, he moves backwards. When Thor hits it in the first Avengers: he’s coming down and cap is rooted, so the energy is spread out. Later, you see they learn to hit it at an angle, to send the shockwave at an angle.
I was under the impression that Captain America's shield was indestructible due to Adamantium inlays and also had vibranium, giving it the physics-defying qualities we see. The steel seems to mostly be there to complete the alloy and retain some semblance of structure so that the shield doesn't just work normally but also isn't just a poorly made shield. Steel is really easy to make alloys from and it's denser than iron so it makes sense that they would use steel for the shield. But since it doesn't seem realistic that Vibranium and Adamantium can become an alloy without extra help
I believe in The Official Handbook of the Marvel Universe it mentioned that Cap's shield had depleted uranium inserts in sections in it. Does this also fall into your equation or does it disrupt it?
I run RPGs and I had an issue with ability of Cap's shield being able to bounce because of the description of it's property of absorbing all kinetic energy is supposed to be absolute. It was simply Comic Book "science" but they are in as different reality, so it may not have the same physics as we do. In the comics it does have another property - It absorbs sound waves, vibrations, and kinetic energy all of it makes the metal stronger. With my issue of Cap's shield, I felt that I had to create a similar metal that did have the properties of complete absorption. It transformed all of the energy into heat, which bled off slowly, as so to not burn the user. I added components to the shield itself to allow it to work with our physics, at least as reasonably close as I can get. I'm not a physicist. But my engineering and physicist friends who played in my game found it to be a good idea. We would just need to find the based metal element to create it.
If I am not mistaken the shield is not laced with Vibranium, but composed of it. It does not come up often enough, but Steve Rogers is a Genius. He is able to calculate how hard, in what angle, and in what direction to throw the shield in order to hit an object, ricochet, and then return to him.
The shield seems to violate thermodynamics frequently, as it appears to bounce off of multiple objects in certain scenes and impart energy *to* them (e.g. knocking guys around, smashing objects) without losing any obvious speed. Now I recognize that if it gets deflected, then the momentum can in principle be accounted for (i.e. it knocks an object backwards and then bounces off, giving its forward momentum to that object while now having a backward momentum from the reaction force it experienced upon impact). Those situations I'm okay with, since we are assuming that the shield is elastic enough to bounce back with almost a perfect return of energy. However, can we say the same for an object that ricochets around the room and imparts force such that objects are knocked around FAR more than the shield's deflection would suggest? This seems as though the shield is effectively "giving" more energy than it is receiving (unless we assume that the shield is ridiculously massive, which doesn't make sense for a lot of reasons). I dunno. Maybe I'm overthinking this. Or maybe I'm leaving out something simple because I haven't had enough coffee today. Anyone got thoughts?
Neat. I used to question the same thing and always figured it was because it was a comic book. The shield's construction is as a solid piece, poured into a form to make a tank hatch.
I've always wondered this: In Captain America First Avenger, Peggy shoots cap and the bullets drop straight down, how is he able to ricochet bullets back at people then when they are yards and yards away?
But in the avengers when Thor hit the shield, all of that kinetic energy was absorbed and redirected outward. Maybe because of the properties of vibranium and the shape of the shield it's designed more so to redirect energy. And because it's released to the side it can use that kinetic energy as a sort of propellant. Which also makes it a good shield because the energy is directed away from the user and spread outward
So, does this mean that any solid projectile striking Capt.'s shield will be "thrown" off of it at a greater velocity than if his shield were made of other materials with a lower coefficient of restitution? - With this question, depending on the solve, Capt. potentially could bounce bullets (lead, copper, steal, etc.) back at aggressors or cause more harm by throwing the hot metal randomly at the various odd angles his shield is struck. For this projected hypothesis to occur I would imagine the vibranium shield to have to remain taught/static, as pictured when Capt. America defends from oncoming fire by covering himself 'firmly' with said shield.
If elasticity and strength is why it bounces, it also helps explain why Black Panther can jump so far and run so fast, as his suit could be specifically tailored to translate that elastic potential energy so that the kinetic energy exerted from what he is pushing off of efficiently becomes kinetic "bounce", just like the shield.
The one superpower people don't know that Captain America has is Flawless Geometry. I mean have you seen some of the crazy angles and number of bounces that his shield goes through before, during and after it has hit it's target(s)?
@Sci_Phile could you explain why, in the first captain america, bucky is sent flying after he uses caps shield to block the rocket if its supposed to absorb and/or send back the energy?
@majormoron nevermind the entire flash, if you were able to accelerate a single playing card to the speed of light, disregarding air friction of course and the fact that the card would disintegrate instantaneously, the impact of said card would yield more power than the Tsar Bomba explosion, the most powerful nuclear detonation ever. The card's impact would yield roughly 61 megatons, whereas the tsar bomba yielded 50. And a card weighs only 1.6 grams. If the flash were to be able to travel at light speed, assuming he weighs in at 80kgs, his steps would generate enough energy to wipe out life on earth in its entirety.
That makes way more sense than I expected, outside of magical explanations obviously. Only problem is that the COR of a human probably isn't very good. All those time the person flies back or metal gets bent, that's lost energy.
I have a theory that the potential energy is stored in the shield like a coiled spring that tightens at the molecular level (which is why it doesn't visibly deform.) I believe the shield also has a "release valve" for this potential energy, which is the shield's edge. That's why bullets hitting the front of the shield just drop to the ground (energy absorbed and stored as potential energy) but when the shield's edge hits a surface, it actually bounces off with MORE force than the initial impact (potential energy released as kinetic energy.) Kind of like a bumper in a pinball machine. We actually see evidence of the edge being the "release valve" in the first Avengers movie. When Thor hits the hammer at full strength, the shield reaches its maximum capacity of potential energy it can hold. And where does all that energy go? Out the sides, as a massive shockwave. If anybody's interested, I wrote up a post about this theory a couple years ago: flavoracle.tumblr.com/post/125971457147/properties-of-captain-americas-shield
My only follow up question would be related to the Thor/Cap hammer shockwave. If the shield is perfectly elastic shouldn't the energy transfer of the shield snapping back to shape also exert force on Cap? In the forest scene Cap is just fine when Thor strikes the shield, but Thor (and most of the trees) get blasted back.
Well, there's also the factor of angles. Cap did take quite a bit of the hit, as you'll notice when he has trouble standing right away. However, the reason he didn't get knocked back while Thor did was because Cap had a solid foundation to support him. Thor came in from above, so all he had was air behind him. Can't exactly hold your ground when you don't have any.
In the comics Stark enhanced Cap's shield with an electro-magnetic manipulator thing to allow Cap to control where his shield goes. Also, in The First Avenger, when Peggy shot at Steve the bullets just dropped to the ground. They didn't ricochet.
But if it absorbs the kinetic energy and then releases it like a spring, sure it can deflect gun fire, but what about the force on cap's arm? It can be dissipated over a larger area, but if he's blocking constant machine gun fire, it should hurt eventually.
Is there a room geometry where Cap's shield could NEVER hit you? NEW mini-ep over on my Insta: instagram.com/sci_phile/ -- KH
*hit
Nerdist Hello! Can we get a “Because Science” on the strength of Luffy’s King Kong Gun from One Piece?
Nerdist There is and there is not. If he throws it with a spin effect like a Tennis ball it might work
Do some black panther
Adamantium vs. Vibranium...what would the outcome be?
I guess I'll have to agree with Peter Parker on this one...
"It doesn't obey the law of physics!"
I searched for this vid while watching civil War because I was heard Peter say that
*that thing doesn’t obey they law of physics
Lol
where are you from?
@@royalwalnutbroth5664 ??
Spiderman: that thing does not obey the laws of physics at all!
Cap: look kid, there's a lot going on here that you don't understand
"Look kid, there's a lot going on here that you don't understand"
"Stark says you'd say that"
Yeah u right lol
6 yrs in the future: “ Stark tell you anything else?”
The weirdness also implies that the material is anisotropic; that is, the properties are different when applied in different directions. For example, the front face of the shield dissipates energy from impacts without rebounding. Some writers explain that the vibranium stores this energy like a battery and releases it when the edges strike things. This explains some of the more ridiculous bank shots Cap manages, since the shield actually can use this stored energy to have a higher velocity after the bounce than before it.
Agreed, especially considering that bullets do not ricochet off Cap's shield, unlike Kyle said. (See Captain America: The First Avenger, shield introduction scene for example.) On the other hand, this presents a problem when using the shield's edge to beat and strike targets. I.e. why doesn't the shield bounce in reaction like the Absent-minded Professor's Flubber shoes? The intensity could be controlled by arguing that energy can only be released from the shield edge in certain amounts. However, we do not see any bounce or extra energy release when Cap uses his shield to beat up his enemies, including Iron Man.
Or that energy is still released, but since Cap is holding it firmly, it just takes effect as a stronger hit, since Cap prevents it from recoiling.
All this from someone with an MLP pfp, I'm sad
Why, because people can both have engineering careers and enjoy MLP? What's the problem here?
the makers of caption america be like
wow. we didn't think that much before making this shit
He should have wrote "Whybranium" at the start of the video.
In-Craig-ible that could be for the episode about black panthers vibration suit being more flexible and comfortable than shorts and crocs
DAMN that's good. -- KH
At the time of my comment: Kyle and the guys are busy with the Muskwatch eps (historic Falcon Heavy reusable main rockets and booster launch) and separate Because Science content to release content that coincides with the BP red carpet world premiere.
Would've been a good tie-up though!
More of Vi-brain-nium
What about that scene in The Winter Soldier where he jumps out the elevator and lands on the shield?
Wouldn't he bounce back up instead of staying on the ground like he does in the movie?
Because he is spread on the more wide part of the shield and not the edge. Remember that you can increase force by refining the impact. Like A hammer bs a hammer and nail. The nail is at a point and the point refine the impact to a singular point and thus creates more force. You ever see the should bouce as much when the shile drops on it's almost flattened side? No. It bounces a little, but because the force is spread, it distribues outward rather than back inward.
I am rather bad at explaining so I hope I explained right.
Scott Sommer I think is trying to say that due to the outer edge of the shield being significantly smaller than the front of the shield it would bounce less and work more like a hammer hitting the ground. What you’re assuming is that there’s no second impact (albeit small) in falls like that, either way it’s why the front of the shield absorbs impacts as it does. The rings compress on one another on a very small scale and absorb the shock of consistent force dispersing it around the shield in a shock wave type manner/widening the force of the impact and especially in terms of beam weapons would disperse the energy to widen the blast so it’s more like a strong wind going by (for one close to the size of the shield’s large frontal surface area). Of course it has been shown to break inside Marvel Comics, but it’s from EXTREME amounts of force that overcome the shields elasticity.
Same thing for when Ag Carter shoots at him and the bullets simply hit the shield and drop... no bounce occurs... there are other scenes that has the same properties.. it only changes when its been thrown... I would say "magic" or an outer ring made of diff metal..
What about all those god blast impact the shield could block? The only explanation is magic. When the writers made up the throw attack, they completely forgot the shield wasn't able to do it at all (no matter how hard Capt might throw it, as soon as it touches the target, all energy would be gone and shield drops. The target would receive no impact what so ever).
If it was just the shield hitting the ground it would probably bounce but something to consider is that PEOPLE don't bounce and so landing on top of the shield would transfer the kinetic energy to your body and you'd still hit the ground like like normal
I'm so impressed with myself. I actually understood all of that. For real.
umm if we watch it all the way through we would have to know what they mean to get to the end
I hope so! It's part of my job when we're learning together to make the journey easier than it otherwise might be. -- KH
Honestly bendy, I don't understand half the thing Kyle usually talks about too but I like watching him anyways
it's still high school physics
Same
When you're early so there's no intelligent comments to read
spartan kitty games Of course not, this isn't a Rick and Morty video where all the geniuses are
Boom -- KH
You're*
His early
DoHickey your right, but you just fixed that by writing a intelligent comment
Do "can you survive a leap of faith?" Next for the release of assassin's Creed origins
The Creed watch game theory matpat did that a while ago
Still I want to see his take on it
You gave me a heart attack Kyle, I thought I broke my phone's screen with your animation (top right of the screen) :P
Now all we need to know is what the paint on Cap's shield is made of.
TBH I'm genuinely surprised that so few people take the shape of the shield into consideration when trying to figure out why it bounces
There is on more thing to consider, and that is the material that the thing bounces OFF of since some energy always has to end up there. Now, if it's a sturdy wall that's probably negligible, but the 'physics' behind the shield actually start not make sense anymore when bouncing off of people. When that happens not only do you definitely deposit energy in the body by deformation, but also by transferring kinetic energy which ends in that person flying through the air. Since the shield apparently never loses it's kinetic energy though, energy conservation is probably violated (or conversation of momentum, alternatively, though in a situation like this they're basically the same thing if you don't want to consider how the shield deposits energy in the form of heat and/or deformation in the person it's hitting.)
Wow... that is a surprisingly intellectual insight... I've given some thought to the subject since watching Civil War, and the only solution to the conservation of energy problem I can come with is that the shield hits the rebounding surface so hard that it causes the surface atoms to fuse, releasing energy. But that's just my opinion, and I apologize if it offends anyone.
I was just about to put a post on the same subject! Another thing that I find physics breaking about his shield is that bullets don't ricochet off it it. They just drop (visual evidence is in Captain America 1 where he gets the shield for the first time). In that situation, should the elastic metal property apply to the bullets as well?
They should have lost a lot of their kinetic potential to the shield, but they definitely should also have ricocheted off of it at a much greater velocity than just falling straight to the ground. For some reason the shield absorbed all of the energy from the bullet, didn't return any energy to the bullet, and didn't let any of the energy pass through the shield and into Cap's arm.
By all means if the shield works the way that Kyle explained it, then even if it was designed to mostly bounce along it's sides, frontal attacks would still have some elasticity and cause forces to act and deal with the transfer of energy.
Huh... never thought of that before... although, if the bullets ricocheted with higher ricochet velocity than incoming velocity, wouldn't that violate conservation of energy?
The bullets don't ricochet because they aren't made of vibranium They deform against the shield
Hedshodd - the one thing mentioned but not explicitly understood in Kyle's explanation is the part with edge vs face surface. While, yes, the movies do seem to contradict themselves a bit by bullets ricochetting sometimes and falling flat other times, the idea is HOW, WHEN and WHERE the elastic energy is expressed.
The vibranium is fused in with the other metals, not simply laying on it in rings, so my belief has always been that any force/energy towards the shield is temporarily absorbed towards the center point. When released back, people think about it as full angular reflection, but I theorize that it mostly radiates outward from center to the shield edges.
So, a lower caliber shot (let's say moving at 200mph or lower) hits the face of the shield, and the kinetic energy of that small thing loses 99% overall of its speed after it transfers into the shield and little reflects back to it. Elasticity action of the shield along vibranium molecule channels bunches it towards the center from almost any angle it is hit, but then radiates most of it back towards the shield's circumference. Essentially most of that bullet's energy transfers out the edges of the shield, and the bullet gets so little back that it barely bounces back. This looks, on the macro level, like the bullet just drops straight down.
With a higher caliber bullet (let's say 700mph+) the same concept applies, but at some velocity the shield's elasticity at the contact point reaches a limit. I will call this limit 500mph at a 6mm sq contact point. The math of this is overly simplified, but from 1-500mph at the small contact point, anything loses 99% of its motion by way of kinetic energy transferring in, absorbed towards the center, then radiated out the edges of the shield (to our naked eyes we do not see the air pushed radially out the edges as that kinetic energy reflects out distributed all around it). The remaining 200mph+ of energy experiences significantly less loss, but still some, as vibratory waves crisscross each other for a split second. This amount acts more like standard reflection, and we see this high caliber bullet bounce back. To our naked eye that couldn't track the bullet to start with, we do not realize how much slower the bullet reflects in the opposite direction, but the behavior is now akin to a low caliber shot (like the previous paragraph's example).
Now, a previous comment mentioned him dropping from a height onto the ground, on top the shield, but this too is treated similarly. Because it is a curved surface, some of the flat ground isn't contacted, and depending on the height of the fall with gravitational acceleration, he is no where near terminal velocity, i.e. he also isn't past the 500mph:6mm sq tolerance point. Further, more than 6mm is being contacted despite curvature, so even at 12mm sq we already have nearly 1000mph of comparable motion/kinetic force being subject to the -99% treatment. This all means that since the ground isn't going to bounce away like a bullet would, up to 1% of the force that can't properly radiate out the front may radiate out the back into Steve. Also, he doesn't bounce back because the 1% force is not enough to push his mass back up significantly. This, from a short fall, equates to a light tap, and this is on a super soldier, so it is far from dangerous to him.
So, in summary, directed momentum mostly radiates out the sides due to elastic channelling to the center then out to the edges at some max tolerance transfer speed (due to vibranium behavior while fused with the unique portions of the metals it is) and turns low caliber into near-stop motion, high caliber into low caliber, and falls into taps.
Hope this makes sense as the reasons the movies seem to contradict themselves but aren't truly totally doing so.
[EDIT - I must add that with edge impacts at certain angles, the fusion pattern reflects nearly all the directional force back, causing the standard bouncy shield behavior. Certain special angles cause vibrational behavior of all the shield's molecules for the reflection to all radiate out, or be channelled along a point. At those special exact angles, the shield acts nearly the same off a solid wall as it would off a person. At other angles, the shield would probably slice into a person's flesh easier, and at all other angles the energy is distributed all around/mostly out all the edges, so it and other objects essentially come to a halt].
Here's my theory: there are straps on the inside. The cross section of the shield perpendicular to the straps are rigid for the cutting effect. The side parallel to the straps, the rings collapses into each other upon impact ever so slightly creating a bounce back effect.
It's why some times that shield seems to flex and other times it's rigid. It all depends on which side of the shield impacts first.
Cap learned this in WW2. Falcon is too stupid to learn this.
I love that the physics adds up so that the bouncing makes sense based on the shield's durability
Can we all agree that intro was perfect?!!!!
If my science teacher explained stuff like this i would have paid more attention in class.
I guess a good example of how well Cap's shield deflects energy is when Thor hits it with Mewmew in the first Avenger film. Love that scene :)
And in Age of Ultron and it takes out a whole squad of Hydra soldiers.. Oh, and a tank.
watching this at double speed is so much fun
Vibranium doesn't absorb energy, it reflects nearly all energy expended against it. In an episode of Spider-Man and his amazing friends, Colossus punches a vibranium wall and knocks himself out. This completely explains how Caps shield works.
it absorbs it then returns it, specifically said "absorbs sound waves, and other vibrations and kinetic energy" then returns it,
and it makes it the vibration stronger.
That moment when you see Tim from Grand Illusions show up in a Because Science video...
How to not have Cap's Shield hit you:
Step 1: escape the area Cap's Shield is currently ricocheting in.
Step 2: profit.
This is basically the 3rd exam for a Calculus based Physics (Mechanics) class lol
Goddamn, i love your show, please never stop doing it, you have so much talent for science and being behind a camera its honestly inspiring, do you ever do a AMA regarding how the show is produced? cuz big props to your crew for making it so smooth
How much force should be applied to a superball to make it bounce on water. Considering the ball is perpendiculary thrown to the water body?
This is one of my favorite intros. He just says "Why?"
This has been a question I've been asking for years. I thought it was a plot device, and you've shown me differently, hats off my dood.
That intro was everything 🤣🤣🤣
Best intro yet, simple, yet thorough.
Very cool; man I love math and physics!!
5:25
Ball bearings from the nile
Science from the Nile.
That joke at the end was amazing oml
Keeps me up at night
Omg, I sent Kyle a message on Facebook asking about this. I doubt that's what inspired the episode, but still awesome to get an answer!
3:22 I lost it 😂
When he said because science and walked off after catching the sheild it was boss asf
But the real question is why did Howard Stark built a shield and not an armour for cap? 🤔
This is what happened-
Howard:" Hey cap we are going to make an armour for you..
(18 hrs later at the facility)-
Howard:" Alright gentlemen lets-
unknown guy: " Im sorry sir but I think that after giving the supersoldier serum to cap it would be worthless to spend billions on building an armour.. why not just give him a shield that is made up of a steel,vibranium and carbon fibre composite material with a coefficient of restitution close to 1?!
Howard: "good thinking ! thanks for the suggestion!"
Unknown guy:" Thats my pleasure."
Howard stark:" But I must say you have a pretty weird beard!"
Nevermind why it bounces I wanna know why it always returns to him perfectly lol
Cap has the ability to think fast so maybe he perfectly and quickly calculate the geometry of the place and threw the shield.
I understand that cap is not as smart as Tony or Bruce but you always see him moving once he threw the shield so he just moves to the place the shield comes back
That was the only correct way to deliver that joke.
That last momment had me laughing soo hard
Stuff like that joke at the end is why you're my favorite nerd Kyle
4:24 So that's why bullets bounce back as well?
The Shield as CoR so close to 1.0 that its only real limiting factor is the fact it is flying through the air. A follow-up to this video would be one that includes the aerodynamics of a frisbee, and how it relates to Cap's Shield.
5:18 Hi Tim!!!
#WaterFromTheNile
Last time I was this early justice league didn't have another trailer
MY MAN -- KH
Elasticity does not explain how the return force is uni-directional, such as when Thor strikes the shield and is blasted backwards along with the surrounding forest, nor does it explain why the shield can seemingly absorb INFINITE amounts of kinetic energy, such as the iconic scene in Civil War with Iron Man firing his repulsors right at the shield. In addition, if we're talking about elastic transfer, then scenes such as Captain America dropping several stories onto the shield should bounce him back up into the air like a trampoline.
Then take into account the sharpness of the edge. At similar visible velocities, the shield can either knock out a human being or embed itself in solid reinforced concrete, or even sheer through various metal armors.
Really, this video should have covered the shield being apparently sentient and telepathically linked to its wielder, able to choose the level of harm inflicted at a moment's notice.
Don't you think the shape has something do to with how it acts when being thrown?
Maybe the face of the shield or y plain was specifically made to disperse on coming energy while the inside of the shield on the x plain was made to redirect energy? because you never see the face of cap's shield redirect energy like the edges do.
That was hilarious
@ Cole Guidry You mean like in Avengers when Iron Man fires his repulsor beams directly at Cap's shield and he uses it to reflect the beam and cut a swath through the Chitauri?
Also, if you re-watch The First Avenger and see the unpainted shield, it looks more like it's made of semi-laminated, concentric rings. While this MIGHT explain its ability to bounce due to contraction and expansion on opposite sides of the rings, it does NOT explain how the same angle and strength of a throw can both knock unconscious a guard and then embed itself into reinforced concrete or steel blast doors.
Well, and coming from a complete Marvel nerd/fanboy, maybe it doesn't follow any laws of physics, hence the quote from ye olde Web-Head in Civil War:
"That thing doesn't follow the laws of physics at all!" And Cap responding with
"Kid, there's a lot going on that you don't understand."
*Obviously* referring to his shield.
Your forgetting one crucial thing. The shield is magnetic. Its shown in 'Age of Ultron' that it's magnetic and that Cap has a device to bring it back to him, so it probably doesn't matter what energy goes where as long as the shield doesn't reach that point of deformity. He just use his force pull (Tony Stark invented SUPER MAGNET) to bring it back to himself or help it on its way.
Plus caps new shield referenced in Spider-man Homecoming is probably chocablock full of gadgets as well.
Jeffrey Gismondo it would also pull other things if that's the case
The shield bounces because they wrote it that way. Nice job on the COR physics though. One part of this situation that always annoyed me though is that the extreme durability of his shield also should be deforming the materials he is hitting with it. There should be lots of dents in the materials he is hitting with it and if it hits a material that is too soft, the shield should stick.
I always tink the shield should act like a twisted spring, but in a molecular level, I mean, it can absorb a lot of energy in one side, and release for other side. this work very well with what we see in the movies, it absorb all the impacts with the front, but bounce when hit with the edge.
That intro is definitely one of the best so far.
That works well if it bounces off a hard object.
Not a person though, since the person seems to absorb energy and goes flying across a room :P
Kyle Hill FTW, great break down as always... all I'm thinking about is how much Cap is "catching" that shield after throwing. Sorry Mr.America, no handshakes for you...
@5:50 "VIBRANIUM LACED RINGS ...ah you did your research. I remember when they showed the incomplete shield in an Ironman movie and you could see the rings going around it.
That's some nice attention to physics on the director's part !
@Nerdist.
They actually show this in the movies:
The shield basically throws what hits it back at them. But, it depends on mass.
Bullets kinda bounce because cap is heavier than bullets.
When he blocks something that weighs more than him, he moves backwards.
When Thor hits it in the first Avengers: he’s coming down and cap is rooted, so the energy is spread out.
Later, you see they learn to hit it at an angle, to send the shockwave at an angle.
This guy and his research team need to be hired as consultants for shows
"G'S! G'S!" Funny physics joke.
I was under the impression that Captain America's shield was indestructible due to Adamantium inlays and also had vibranium, giving it the physics-defying qualities we see. The steel seems to mostly be there to complete the alloy and retain some semblance of structure so that the shield doesn't just work normally but also isn't just a poorly made shield. Steel is really easy to make alloys from and it's denser than iron so it makes sense that they would use steel for the shield. But since it doesn't seem realistic that Vibranium and Adamantium can become an alloy without extra help
"It's gone rogue!"
Infinity plus one! LMAO
This is a great episode. Top-notch sciencing Kyle!
Thank you very much Joel! -- KH
I believe in The Official Handbook of the Marvel Universe it mentioned that Cap's shield had depleted uranium inserts in sections in it.
Does this also fall into your equation or does it disrupt it?
I run RPGs and I had an issue with ability of Cap's shield being able to bounce because of the description of it's property of absorbing all kinetic energy is supposed to be absolute. It was simply Comic Book "science" but they are in as different reality, so it may not have the same physics as we do. In the comics it does have another property - It absorbs sound waves, vibrations, and kinetic energy all of it makes the metal stronger.
With my issue of Cap's shield, I felt that I had to create a similar metal that did have the properties of complete absorption. It transformed all of the energy into heat, which bled off slowly, as so to not burn the user. I added components to the shield itself to allow it to work with our physics, at least as reasonably close as I can get. I'm not a physicist. But my engineering and physicist friends who played in my game found it to be a good idea. We would just need to find the based metal element to create it.
It's weird that I watched this while throwing a bouncy ball at my wall.
This just brings up more Questions.
I seem to remember a very old issue that said that Cap's shield was a mixture of vibranium, adamantium and other stuff.
Man you can talk fast, and science good
If I am not mistaken the shield is not laced with Vibranium, but composed of it. It does not come up often enough, but Steve Rogers is a Genius. He is able to calculate how hard, in what angle, and in what direction to throw the shield in order to hit an object, ricochet, and then return to him.
"No, thank YOU Kyle." #ScienceThor
at last 😍😍
I had subscribed just cuz of this guy
A Hendrik Ball cameo from Grand Illusion channel on Because Science = Nerdism overload
The shield seems to violate thermodynamics frequently, as it appears to bounce off of multiple objects in certain scenes and impart energy *to* them (e.g. knocking guys around, smashing objects) without losing any obvious speed.
Now I recognize that if it gets deflected, then the momentum can in principle be accounted for (i.e. it knocks an object backwards and then bounces off, giving its forward momentum to that object while now having a backward momentum from the reaction force it experienced upon impact). Those situations I'm okay with, since we are assuming that the shield is elastic enough to bounce back with almost a perfect return of energy.
However, can we say the same for an object that ricochets around the room and imparts force such that objects are knocked around FAR more than the shield's deflection would suggest? This seems as though the shield is effectively "giving" more energy than it is receiving (unless we assume that the shield is ridiculously massive, which doesn't make sense for a lot of reasons).
I dunno. Maybe I'm overthinking this. Or maybe I'm leaving out something simple because I haven't had enough coffee today. Anyone got thoughts?
Another great episode. I would really love to see what it looks like when you're making one of these.
i love this series
Me too, thanks Magnus. -- KH
How does after image work? The octopus guy in the anime took it to the next level.
Neat. I used to question the same thing and always figured it was because it was a comic book. The shield's construction is as a solid piece, poured into a form to make a tank hatch.
I've always wondered this: In Captain America First Avenger, Peggy shoots cap and the bullets drop straight down, how is he able to ricochet bullets back at people then when they are yards and yards away?
Kyle Hill is the MAN!
That moment when your boss comes in 1:00
A short on FTL travel and / or warp drive would be interesting. :)
nice finally cought it when it uploaded
like how your changing the endings up
But in the avengers when Thor hit the shield, all of that kinetic energy was absorbed and redirected outward. Maybe because of the properties of vibranium and the shape of the shield it's designed more so to redirect energy. And because it's released to the side it can use that kinetic energy as a sort of propellant. Which also makes it a good shield because the energy is directed away from the user and spread outward
So, does this mean that any solid projectile striking Capt.'s shield will be "thrown" off of it at a greater velocity than if his shield were made of other materials with a lower coefficient of restitution? - With this question, depending on the solve, Capt. potentially could bounce bullets (lead, copper, steal, etc.) back at aggressors or cause more harm by throwing the hot metal randomly at the various odd angles his shield is struck. For this projected hypothesis to occur I would imagine the vibranium shield to have to remain taught/static, as pictured when Capt. America defends from oncoming fire by covering himself 'firmly' with said shield.
That graf was incorrect to a point but neverthless its an awesome episode keep it up
If elasticity and strength is why it bounces, it also helps explain why Black Panther can jump so far and run so fast, as his suit could be specifically tailored to translate that elastic potential energy so that the kinetic energy exerted from what he is pushing off of efficiently becomes kinetic "bounce", just like the shield.
The one superpower people don't know that Captain America has is Flawless Geometry. I mean have you seen some of the crazy angles and number of bounces that his shield goes through before, during and after it has hit it's target(s)?
This guy is the real life Cisco Ramone
@Sci_Phile could you explain why, in the first captain america, bucky is sent flying after he uses caps shield to block the rocket if its supposed to absorb and/or send back the energy?
Great episode, but the joke at the end was cringy.
Can u do the flash being a weapon of mass destruction at light speed?
Infinite Mass Punch? They did that one.
I know man, I own the cringe. Look at my stupid face -- KH
IMP Has been done and the Speed Force keeps Barry, both Wally's, and Jay from flatening and incinerating everything
where can i find that?
@majormoron nevermind the entire flash, if you were able to accelerate a single playing card to the speed of light, disregarding air friction of course and the fact that the card would disintegrate instantaneously, the impact of said card would yield more power than the Tsar Bomba explosion, the most powerful nuclear detonation ever. The card's impact would yield roughly 61 megatons, whereas the tsar bomba yielded 50. And a card weighs only 1.6 grams. If the flash were to be able to travel at light speed, assuming he weighs in at 80kgs, his steps would generate enough energy to wipe out life on earth in its entirety.
That makes way more sense than I expected, outside of magical explanations obviously.
Only problem is that the COR of a human probably isn't very good. All those time the person flies back or metal gets bent, that's lost energy.
I have a theory that the potential energy is stored in the shield like a coiled spring that tightens at the molecular level (which is why it doesn't visibly deform.)
I believe the shield also has a "release valve" for this potential energy, which is the shield's edge. That's why bullets hitting the front of the shield just drop to the ground (energy absorbed and stored as potential energy) but when the shield's edge hits a surface, it actually bounces off with MORE force than the initial impact (potential energy released as kinetic energy.) Kind of like a bumper in a pinball machine.
We actually see evidence of the edge being the "release valve" in the first Avengers movie. When Thor hits the hammer at full strength, the shield reaches its maximum capacity of potential energy it can hold. And where does all that energy go? Out the sides, as a massive shockwave.
If anybody's interested, I wrote up a post about this theory a couple years ago:
flavoracle.tumblr.com/post/125971457147/properties-of-captain-americas-shield
So would this video also explain why Moljnir bounced off the sheild and blow everything backwards? And why was the blowback so strong?
My only follow up question would be related to the Thor/Cap hammer shockwave. If the shield is perfectly elastic shouldn't the energy transfer of the shield snapping back to shape also exert force on Cap? In the forest scene Cap is just fine when Thor strikes the shield, but Thor (and most of the trees) get blasted back.
IcarusAloft maybe it's a one way transfer. It returns the energy is the opposite direction only.
But...but...Newton's third law
Watch that scene again, he's a little slow to get up as well.
Two words:
Magic. Hammer.
Well, there's also the factor of angles. Cap did take quite a bit of the hit, as you'll notice when he has trouble standing right away. However, the reason he didn't get knocked back while Thor did was because Cap had a solid foundation to support him. Thor came in from above, so all he had was air behind him. Can't exactly hold your ground when you don't have any.
In the comics Stark enhanced Cap's shield with an electro-magnetic manipulator thing to allow Cap to control where his shield goes.
Also, in The First Avenger, when Peggy shot at Steve the bullets just dropped to the ground. They didn't ricochet.
I think you just helped me with engineering course work haha.
But if it absorbs the kinetic energy and then releases it like a spring, sure it can deflect gun fire, but what about the force on cap's arm? It can be dissipated over a larger area, but if he's blocking constant machine gun fire, it should hurt eventually.
I want Kyle to tell me what's really stronger/better caps shield or thors hammer or what would really happen if they collided
Because super balls, that's why.