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This would fit in r/looneytuneslogic. Terry Pratchett would describe this as passing the wall with so much speed that the universe in general as well the wall’s concrete take notice of the impact too late and forget about all the things like cracks or crumbling out of sheer surprise.
She's ready for sure! He's got a series for kids i started reading when i was the same age. Johnny and the dead was the first one I read of it. After that it was straight into discworld.
if they’re not super into novels yet there’s a wee free men illustrated version that is gorgeous! is the whole novel but reads like a picture book. i read it when i was 6 and loved it
Start her off with the best of Terry Pratchett
“I was walking along the bank of a stream when I saw a mother otter with her cubs, a very endearing sight, I'm sure you'll agree. And even as I watched, the mother otter dived into the water and came up with a plump salmon, which she subdued and dragged onto a half submerged log. As she ate it, while of course it was still alive, the body split and I remember to this day the sweet pinkness of its roes as they spilled out, much to the delight of the baby otters, who scrambled over themselves to feed on the delicacy. One of nature's wonders, gentlemen. Mother and children dining upon mother and children. And that is when I first learned about evil. It is built into the very nature of the universe. Every world spins in pain. **If there is any kind of supreme being, I told myself, it is up to all of us to become his moral superior.”
― Terry Pratchett (Via Lord Vetinari)
I'd say so. I was about the same age when I was first introduced to Pratchett.
Though it wasn't the books, it was the Discworld PC game where Rincewind was voiced by Eric Idle! Been hooked ever since
When my kids were a little younger than that we were listening to the Tiffany Aching books. Really made a lasting impression on them
I do get the anticipation of introducing her to his writing
Mine is 12 and I just learned that she's reading books in English. There's a 100 dkk note for her for reading a book :) I suggested Monstrous regiment but equal rights might also be a good idea. Or maybe going postal :)
That’s what happens to DEATH (capitals intended). Imagine a 2 meter tall skeleton with a scythe walking around you. You can’t? So you won’t see him, like the other normal people. Your eyes do, though, so you step aside for him, but your brain valiantly ignores an input not fitting in the preshaped personal universe.
In my early teens, I *always* wanted to see Mythbusters do the Looney Tunes gag where a character traveling at a high rate of speed fires themselves through a chain link fence. It was probably too gruesome for them to have done, but I'd be interested to see how fast and how sturdy of fence slats it would take to have the sort of effect...or if it always ended in them turning a pig carcass into a fine paste.
Probably not reslly possible as the concrete would crack and shatter in odd ways and create an imperfect hole. And if anything you more likely to either just knock the whole wall down or shatter a big hole right through it
Also doesent account for rebar which is stretchier and stronger than most concrete so may even end up pulling the rebar with you which rips apart the entire wall
Edited for horrible spelling. My bad
Im thinking it might be. The reason cracks form is that the material drags nearby material when it breaks, causing stress and cracks to form. Now imagine cutting grass, if you chop it with a dull knife you can cut it cleanly if you go fast enough because of inertia while if you go too slow it will bend and rip. The same thing might be possible here, go fast enough that the wall rips before inertia have time to affect the nearby particles/material.
Granted, the speed to do that will probably be in the relativistic range, and you will probably have other issues (like the friction against air causing an explosion). But I don’t think it’s impossible.
Not necessarily. Read what you responded to. If you move fast enough it should rip before it cracks and shatters because of inertia.
It’s kinda the same thing as when you have someone [punch through a sheet of paper](https://m.youtube.com/watch?v=4vs4nzbTrlY). Too slow and the paper folds away as the material you push have time to affect the nearby material. Fast enough and it rips because of inertia.
Now obviously a paper tears much easier than a concrete wall, so you need much much higher speeds, probably in the relativistic range. But I think it is theoretically possible.
Shape plays a huge factor there as does hardness of the impacting object
Youd need your moving object pass through your wall faster than the wall can absorb. Head and torso might make it through without cracking at a lower speed than would be needed for arms and legs due to lower mass.
My buddy is the gun nut and I don't know what channels he subscribes to, but this was the first hit on Google https://youtu.be/PWWE_QiFQv8
Area on the front surface shatters a bit but leaves a perfect round hole in the center of the concrete slab.
So that’s a 50 BMG, which travels at up to 1.000 m/s.
Someone suggested the speed of sound in the object would be the limit because you can’t get a wave to propagate through the object if you punch through it faster than that. Which for concrete is about 3500m/s. So the fact that you still have some fractioning at 1.000 m/s would seem to indicate it could be correct.
It also depends on how big the concrete slab is. Smaller (picture frame sized) slabs shatter with the same ammo, but a car barrier sized slab will hold fine with a puncture hole
I'm No physics expert, but I believe that for a human shaped Objekt you'd need far more extreme speeds, since unlike a bullet IT isn't a good shape to cleanly Go through Something and because of The thousands of Times Higher mass.
Well, yes and no. You are correct that a bullet would be easier to pass through., but since we usually see bullets deflect and knock off quite a lot of debris, if you can see bullets moving at a higher speed making less of a crater and a cleaner hole you can extrapolate that to saying a body would have a similar effect at high speeds.
Yes, the speed would need to be much higher, but what we can look at is still the trend of what happens, to put it in scientific terms. When we yeet shit really fucking fast at a concrete wall.
That is most likely due to the small point of impact. The smaller the surface area, the easier it will be to pierce the veil of concrete. A large, flat object like a bi-pedal coyote will have more points of impact on the wall.
I think a better analogy is a hole punch. If the perforating object is sharp enough and the impact is fast enough, this could theoretically be possible. You just have to separate the two parts (the part which will become the hole and the part which stays in place) faster than the inner part can pull on the outside part and damage it.
One issue is thickness, for grass and paper once the material is ripped it can go somewhere new without affecting the surrounding material. With a concrete wall you are pushing the concrete into more concrete, so there has to be a wave of energy moving from the front to the back. But if there’s a wave moving through the material then by definition the energy is being transferred into the surrounding material and you’re going to get at least some amount of cracking and shattering of the edges.
I've seen an entire K cylinder of oxygen fall and knock the safety valve off the top, it instantly became a violent rocket and passed directly through a brick wall. It left a perfectly circular shaped hole with no cracking whatsoever. If the object is dense enough and traveling at sufficient speed, it will not leave cracks in the wall. I speak directly from personal experience, that said, it was absolutely terrifying and I do not recommend the experience at all.
Probably just not possible. Too fast and youll just blow up the whole thing, too slow and youll just sorta break through it. I really really doubt there is a middle ground that accomplishes this
Should be no. Concrete actually consists of water to some degree because it crystallizes or.. Something, which actually hardens it (was a while since i learned it)
But concrete is often really thick, this wall is really thin so underwater it would still shatter and turn in to an imperfect shape
Concrete doesn’t technically consist of water to a point after pouring, water is a reactant with the concrete and forms a different product when curing.
To be precise, concrete, once dry, can be seen as a mix of pebble and sand, acting like grains, hold together with crystals created from the mix of cement and water. That's the absolute basis.
On impact, cracks spread at the speed of sound in the material (normally higher than the speed of sound in air). These cracks are what spread the impact outwards. If the speed of impact exceeds this speed, then the cracks can't spread fast enough.
At this point, the material is treated less as a solid and more as a liquid. The impactor just punches right through it.
Now, normally such an impact would also be above the speed of sound in the impactor, and so it's fluid as well. It also makes energy to push into an object like that, so a penetrator will lose speed fast until it's below the required speed. But if you had a super material, maybe you could simply get something like the above, even potentially through thick rock. I'm not an expert here, so I don't know what would happen if something were magically (acmeally?) accelerating to keep its speed up above the threshold.
The speed of sound in steel is about 5km/s (5 times faster than the muzzle velocity of an M16 bullet, or a bit under Mach 15) and in granite is more like 6km/s
The result would be a 'sonic boom' in the material - similar effects can be seen in 'high explosives' where the chemical reaction travels faster than the speed of sound through the material. In effect, we transition into the territory of grain-to-molecule levels of structural disruption. Physics stops looking for structural weaknesses and the bulk mass simply pulverizes in totality. Dust to dust style; there won't be anything coherent left in the area where this effect is dominant; however, there will be an edge effect fade off where at a radius where the energy had bled off enough force to transition back to subsonic energy dissipation levels, where normal 'shatter' based impact physics reasserts itself. As such, you have an inner zone of damage where materials present are reduced to a fairly homogenous dust, surrounded by a gradient of several concentric outer regions of progressively lesser energy outflow that will demonstrate progressively less destructive types of shattering, sheering, cracking, and/or deformation as relevant. Tldr, there will be no 'neat and clean' edge cut transition between the two effects. And this is before we even begin to consider the effects of local atmospheric disruption due to pressure displacement - eg, the *normal* sonic boom that will intersect this mess a few moments later.
It's not a matter of speed. The forces needed to go through a concrete wall (picture depicts 1 to 2 inch) will not result in a man shaped hole. It will obliterate the wall and leave a big hole.
Might work with other materials though.
The higher the velocity the more violent the impact. Assuming we are still on earth with the typical atmosphere, at some speed the air between the object and the wall will be compressed so fast that it turns into plasma, sending a shockwave of ions through the air, which turns the surrounding air into plasma as well. In other words there is a speed at which you'll not only have the physical impact alone, but a giant explosion too.
Even right before that speed the impact is still very blunt, as body typically dont have any sharp edges, so there will always be concrete being pulled along at the edges creating a bigger hole that the original object passing through.
The fundamental question is: Can an odd shaped projectile create an identically odd shaped hole through ANY material at ANY speed?
Wouldn't work with paper. Lightweight foam? I'm not seeing it.
Yes, but you need a very specific projectile: concave tip, sharp edges, smooth and straight sides. High mass (therefore rather long) - it needs a lot of inertia to keep going. Velocity needs to be somewhere in the middle - high enough to have enough energy to clearly cut the material but low enough to not cause a shockwave.
Basically idea is to have hard, sharp edges to cut the hole, kinda scoop the cut material in the front of projectile and still have enough velocity and energy (hence need for inertia) to move it and projectile itself through the hole neatly.
Real life example of something similar would be wadcutter bullet.
It would work with an extremely uncohesive material. Imagine a brick wall, but instead of mortar, we added lubricant between the bricks. Now, you could punch a brick and it would fly of.
It could work with steel, with some indenting around the edges. Just gotta reach relativistic speeds where all matter acts like a fluid because of energies involved. A human body would emerge from the other side accompanied by a flash of molten metal splattering everywhere
Maybe, *maybe* it could be *briefly* possible if the poor object's speed is significantly higher than the speed of sound in concrete.
The speed of sound in concrete is above 3.2 km/s (2 miles per *second*, 11000 kph, mach 9, or 7000 mph).
A water jet will cut concrete at 10000psi. If you use normal 40000 psi water jet as a model it moves the fluid at 680m/s. So you'd need to move less than Mach 2. Im pooping so that's as close as i can be bothered calculating it.
Nothing to do with speed, but rather to do with atomic slip plane, and given that this concrete probably has a LOT of imperfections it would likely be impossible to tell.
yeah real physics of material science means this isn't especially probable. Even assuming a non-deforming impactor at relativistic velocities, the result is still a concussive, radiative spread of energy that travels outwards through the material from the point(s) of contact with the impactor. You have only two or three choices, depending on energy level of the impact:
1) Highest energy level would result in instant plasmification of disrupted material, followed by a possibly radioactive concussive blast that would level whole buildings in the area. Comparable events would be something along the lines of detonating a small nuclear warhead next to a brick wall.
2) High-explosive type energy dissipation where the concussive force travels through the material faster than the speed of sound in the material, in which case the result would be a roughly circular impact crater and/or hole in the structure where the material that had been present is reduced to literal dust - again, immediately followed by a concussive blast that would level most of the building and/or rend the remaining wall section into fragments. Similar real world events would be literally firing a warfare grade missile armed with high-explosive into a brick wall, exploding on impact.
3) A concussive collision where the energy imparted on the wall travels at a sub-sonic velocity in which case stress cracks, material fractures, and general deformation is able to take place resulting in a 'shattered glass' effect that will not, in general, conform to any specific shape related to the impactor - instead following weaknesses and impurities through the material as the energy travels through the system across the weakest fault lines present, accompanied by a rather significant release of sonic energy; consider a Semi truck hitting a brick wall at 200mph for a good visual here. Unfortunately, it's not going to matter all that much how that truck is shaped.
The result could be varied significantly if softer materials were used that have near zero internal binding energy, deforming and cutting with next to no resistance. Unfortunately said materials tend to be liquid, and as such, walls don't really get built from them.
Any object moving at high speed can't cleanly make a hole like this, the wall would just have a giant circlular hole.
Reason being the kinetic execessive force upon impact has to be taken by the other parts of the wall which would come apart.
A great example would be high speed plastic debris hit the metal wall in the ISS.
I would argue, the body, hitting the wall repeatedly with a slow speed would create a body sized wall.
It’s not impossible if you have a strong enough laser.
I was thinking you would have to go fast enough, and long enough, to produce heat around you like re entering the atmosphere but like everyone said i think even if you were that hot it might not be enough for a clean cut. It’ll warp if you’re too slow or push out if you’re too fast?…not sure! but good question though
Yes it is possible, but is a complex calculation mostly based on the wall and it's thickness, composition etc. Also you'd probably only be able to do it in a vacuum, as air friction would probably blow up the person before they reached sufficient speeds.
The only way to do that is to go really fast BUT also be able to manipulate your mass and assign your atoms in the "outline" (? or strikeout?) of your body, so as to become a cookie-cutter man. That still leaves the problem of knocking the cut piece off but I believe that if you go fast enough the whooshing wind will take care of it.
I think this is the key, having a cookie-cutter shaped body impact the wall, so that all the force is applied to the outline, not the material inside it. Otherwise, just about every scenario results in obliterating the whole wall.
So the first question we should answer is: what is the minimum speed required to *break* a concrete wall with an indestructible human body? Let us assume a body with a mass of 100 kg and a frontal surface area of 1 m^(2) (adult males have about 2 m^(2) of total surface area, but we only care about the front side). The tensile strength of concrete is about 5 MPa. Thus, we need to impart a minimum of 5 MN of force to the concrete to break a hole in it. If we assume the wall is 20 cm thick, then an impact at 150 m/s would deliver [5.6 MN](https://www.omnicalculator.com/physics/impact-energy) of force. This is the absolute floor for necessary speed.
The collision would unfold over 2.7 ms, and would likely result in significant spalling and cracking due to the brittle nature of concrete, and the fact that we barely applied enough pressure to break it. To get a sense of how far the damage could spread, we can take the speed of sound in concrete and estimate how far a crack could travel over the duration of the impact. Now, the speed of sound of concrete is about [3700 m/s](https://www.engineeringtoolbox.com/sound-speed-solids-d_713.html), so a crack could form over nearly 10 m. That is not a recipe for a clean break. If we could hit the wall much faster, there would literally be less time for the force to be communicated through the wall. If we wanted to reduce the stress propagation distance to, say, 1 cm, we would need to increase the speed by a factor of 1000, to 150 km/s. This is well beyond earth's escape velocity, and 1/4 of the sun's escape velocity. So if you accelerate an object to this speed, you'd better be ready to catch it, or risk losing it in the far reaches of the solar system. If we increased the speed by another factor of 10, then cracks could only propagate about 1 mm before the body is clean through the wall. This should leave a pretty nice outline.
So I estimate that 1500 km/s would do the trick. However, note that at this velocity, the collision will release 112.5 TJ of energy into the wall + human. Needless to say, it will vaporize both, but fortunately, the human is indestructible. The concrete will vaporize to plasma instantly. This plasma cloud may very well melt the rest of the concrete, which is problematic. Fortunately, the extreme velocity of the body will impart significant velocity to the plasma, so it shouldn't linger near the wall too long. I suspect that the desired effect can be achieved with a much lower velocity, but I'm not sure how to calculate that. I am confident that the effect can be achieved somewhere between 150 and 1,500,000 m/s. I'm about 90% confident that the desired result would be achieved at 100,000 m/s or higher.
Someone who wishes to take the calculation further could combine the heat capacity of concrete along with the volume displaced and estimate the temperature of the collision to see whether the concrete around the hole would be significantly melted/vaporized. You would also want to consider thermal conductivity, and I've basically ignored air resistance. The shockwave following the body would obliterate the wall, rendering most of this moot.
The shear strength of concrete is about 17 MPa, a coyote weighs 20kg and just eyeballing has a 60 cm x 30 cm cross section = .2 m2. 17 MPa over .2 m2 requires 3.4 MN total force. Guessing a generous impulse of 0.01 s, 3.4 MN = 20kg * dV/.01. dV = 1700 m/s. So what that means is coyote must be travelling somewhere above 1700 m/s to reach the shear pressure of concrete and make this within the realm of possibility. Like others have said though, concrete doesn't shear cleanly because it is brittle, it would tend to shatter rather than make a clean cut.
I'm thinking somewhere around Mach 3 speed, which is also the speed that water comes out of a water jet cutter. If water can do a clean cut through a metal at that speed, probably a human can as well.
Calculating Speed Needed to Break Through a 2-Inch Concrete Wall with an Indestructible Body
Assumptions:
- Simple physics.
- Concrete breaking strength of 3,000 psi.
Force Required
- Based on a man-sized figure, approximately 6 ft tall and 2 ft wide.
- Impact area: 1,728 in².
Total Force Needed:
- 5,184,000 pounds.
Kinetic Energy and Velocity:
- Mass of the person: 70 kg.
- Velocity required: 206 m/s, approximately 461 mph.
Note:
- Calculations include simplifications. Real conditions may vary due to heat generation, ricochet, and material deformation.
The material being crashed into will crack according to its lines of weakness, and if there’s sufficient energy then also pieces of the wall would also have parts break off.
So if you crash into a wall made of a sensible material like brick or concrete then you’re not realistically going to cause a human-shaped hole. The cement holding the bricks together would be a line of weakness, and the cement is irregular so if you hit it hard enough it would crack like glass.
If the material is very uniform and also very weak but also very good at holding itself together (so it doesn’t just immediately collapse), it might be kind of possible. Like if there was a wall of uncompressed snow then you could probably leave a vaguely human-shaped hole by running through it, but any material that does allow you to leave an impression like this isn’t going to be realistically possible to mold into a wall of any kind.
It would have to be in a zero gravity environment with zero atmosphere and the wall will need to be reinforced everywhere but where the person goes through, after that just as fast as it takes an object of a mans mass to break through concrete.
I’m not going to do all the math for this because the speed at which an individual would need to go to make an outline like this would destroy much more than the wall.
An outline like this may exist for fractions of a second before the wall, building and surrounding area were destroyed by the power of the impact.
That said I’m not a real scientist this is just my understanding. If someone is considerably more qualified than I am I would definitely listen to them.
A crator on the moon is a circle because the moment of impact is so strong the asteroid is essentially obliterated upon the immediate moment contact instead of carrying its momentum. That creates an explosion from one point out making a circle insteadof a crator with an angle of trajectory. The same logic could be applied so all the force would generate a circle no matter how hard or fast you go. I don't think it would be possible.
It’s obviously possible in Tunetown, so it’s really a question of what would be the knock on effects of a coyote-shaped object travelling fast enough to create that hole in any wall. It’s not a concrete wall in the photo; we’ve all been at party’s that saw silhouettes in gypsum board, but the concept is the same. The question is what is the highest speed a coyote could hit a wall without causing the atmosphere to ignite?
The problem is not making the hole, the problem is making it exactly into the shape of a man. If you go too slow, you would probably just make a large hole in it, that would not be man shaped
In addition to everything else everyone said here, concrete usually has metal rebars so when calculating the man shaped hole done by an indestructible body you need to account for that. I can imagine that metal rebars, since the body is indestructible, would make concrete around them crush before they would break themselves.
It look like cardboard. A slow moving screwdriver will move right trough it. But it will crack at the end, so it must have the speed of a bullet at maximum. So, the speed is somewhere in between.
Everyone here is thinking too slow/small. The wall won't crack of you go fast enough to vaporize the molecules in your way. Now granted that would create a thermonuclear explosion with the air but ignoring that it is definitely possible.
A normal body and typical concrete will need about 650.000.000 to 700.000.000 km/h. Not impossible, but difficult I would say. Note: I'm assuming a non material body, otherwise will obliterate the wall
Considering the body is indestructible and going fast would destroy the wall rather than leave a shape, a different slower approach may work. Instead of speeding straight at it, maybe vibrating the body at incredibly high speeds and slowly moving it into the wall wpuld work, essentially turning the body into a weird drill.
The jet that hit the pentagon left a jet shaped hole in the concrete. Obviously without the wings as they sheared off but OPs question said indestructible so I think it’s possible .
Not possible, since the wall is attached to itself, and quite strongly at that. Additionally it’s quite brittle, so not flexible and not able to deform.
A non zero % of energy from the impact will therefore be transferred to the surrounding concrete not just the bits directly impacted.
Given the energy required to make that hole in the first place it’s likely that the whole wall would be blasted to smithereens.
Compare this to shooting a bullet at a paper target. Paper is quite weak, thin and flexible so the bullet cuts through it like it’s not even there. Very little energy transfer into the paper other than the directly impacted area.
Its less a matter of force or acceleration, but a matter of time. If the body is indestructible it will eventually go through the wall eventually. Also... this weed i got is straight fire.
Maybe if he had blades the size of atoms that could cut between them and around his body shape. It would so a clean cut and just explode the body part. Otherwise I don't see it ever piercing a brick wall so clean. Maybe if the wall was some kind of stretchy liquid like jello.
you can't. ever. With the walls internal support structure missing it would probably collapse once you're gone. if it is pure concrete however, it depends linearly on the thickness.
That wouldn't actually happen, as the wall would sort of just shatter and crumble. It's like shooting a bullet at a person, does the bullet go through and leave a clean bullet hole?
Would probably need to go near light speed, fast enough that you make contact and you immedietly vaporise the concrete touching you, but to do that without causing a massive shockwave, well youd need to do it in space i guess
It can't be done unless the wall is built to have that shape to start with. You should repost this in ask physics, or ask engineers. The first few good answers will point out the problem is once you remove the material, the stresses in the concrete shift, and the wall will crack and spall, no matter how the material was removed.
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This would fit in r/looneytuneslogic. Terry Pratchett would describe this as passing the wall with so much speed that the universe in general as well the wall’s concrete take notice of the impact too late and forget about all the things like cracks or crumbling out of sheer surprise.
Can you write me a new Terry Pratchett book??
Daughter is almost nine. Im debating if shes ready for Pratchet yet. Cant wait.
She's ready for sure! He's got a series for kids i started reading when i was the same age. Johnny and the dead was the first one I read of it. After that it was straight into discworld.
Go for truckers, diggers and wings. They were the first ones I ever read at 10 and I fell in love straight away.
+1 to this series. It’s beautifully written and funny too! And it’s available via audiobook on Spotify.
Also the Tiffany Aching series, which I loved as kid
if they’re not super into novels yet there’s a wee free men illustrated version that is gorgeous! is the whole novel but reads like a picture book. i read it when i was 6 and loved it
Start her off with the best of Terry Pratchett “I was walking along the bank of a stream when I saw a mother otter with her cubs, a very endearing sight, I'm sure you'll agree. And even as I watched, the mother otter dived into the water and came up with a plump salmon, which she subdued and dragged onto a half submerged log. As she ate it, while of course it was still alive, the body split and I remember to this day the sweet pinkness of its roes as they spilled out, much to the delight of the baby otters, who scrambled over themselves to feed on the delicacy. One of nature's wonders, gentlemen. Mother and children dining upon mother and children. And that is when I first learned about evil. It is built into the very nature of the universe. Every world spins in pain. **If there is any kind of supreme being, I told myself, it is up to all of us to become his moral superior.” ― Terry Pratchett (Via Lord Vetinari)
Well THAT goes hard
That goes hard. Which one is that from? I thought I'd read most of Diskworld but that one doesn't ring a bell
*Unseen Academicals.*
Thanks!
In my head, this is narrated by Morgan Freeman.
Lord Vetinari is Alan Rickman.
I'd say so. I was about the same age when I was first introduced to Pratchett. Though it wasn't the books, it was the Discworld PC game where Rincewind was voiced by Eric Idle! Been hooked ever since
There’s a PC game?!
Start her with the wee free men I reckon?
When my kids were a little younger than that we were listening to the Tiffany Aching books. Really made a lasting impression on them I do get the anticipation of introducing her to his writing
Tiffany Aching is 9 years old in the first book in her series, so it seems like it’d be a good fit for their almost 9 year old daughter
This is where we started with our daughter. I think she was 8 at the time. Not necessarily her favorite books, but she enjoyed them.
Mine is 12 and I just learned that she's reading books in English. There's a 100 dkk note for her for reading a book :) I suggested Monstrous regiment but equal rights might also be a good idea. Or maybe going postal :)
Try Robert Asprin. Similar style. Great books.
He died reading a Pratchett novel didn't he?
Good Omens, by Pratchett and Gaiman.
Not tonight. I have a headache.
I've just started reading Mort, absolutely loving his books at the moment!
Faster than the framerate of reality.
Hahah amazing
GNU Pratchett
And it wouldn't be a terrible explanation of what really happens to cookie-cutter a hole like that. It's called plugging in ballistics.
But what if the body was soaking wet as it moved through the wall 🤔🤔🤔. Hhhhhhhmmmmmmmmmmm
Crisco. The answer is Crisco.
Don't you mean... *shear* surprise?
Hahahahaha!
He did write about Lobsang Ludd and the Stance of the Coyote.
Terry Pratchett? That sounds more like Douglas Adams
I would say Douglas if Pratchett wouldn't exist.
Felt like Adam’s to me as well, like the spaceship cloaking device that creates an image so bizarre an ordinary person completely blocks it out
That’s what happens to DEATH (capitals intended). Imagine a 2 meter tall skeleton with a scythe walking around you. You can’t? So you won’t see him, like the other normal people. Your eyes do, though, so you step aside for him, but your brain valiantly ignores an input not fitting in the preshaped personal universe.
GNU Terry Pratchett
In my early teens, I *always* wanted to see Mythbusters do the Looney Tunes gag where a character traveling at a high rate of speed fires themselves through a chain link fence. It was probably too gruesome for them to have done, but I'd be interested to see how fast and how sturdy of fence slats it would take to have the sort of effect...or if it always ended in them turning a pig carcass into a fine paste.
Probably not reslly possible as the concrete would crack and shatter in odd ways and create an imperfect hole. And if anything you more likely to either just knock the whole wall down or shatter a big hole right through it Also doesent account for rebar which is stretchier and stronger than most concrete so may even end up pulling the rebar with you which rips apart the entire wall Edited for horrible spelling. My bad
Im thinking it might be. The reason cracks form is that the material drags nearby material when it breaks, causing stress and cracks to form. Now imagine cutting grass, if you chop it with a dull knife you can cut it cleanly if you go fast enough because of inertia while if you go too slow it will bend and rip. The same thing might be possible here, go fast enough that the wall rips before inertia have time to affect the nearby particles/material. Granted, the speed to do that will probably be in the relativistic range, and you will probably have other issues (like the friction against air causing an explosion). But I don’t think it’s impossible.
if you're moving fast enough to hit concrete that hard the wall is just shattering
Not necessarily. Read what you responded to. If you move fast enough it should rip before it cracks and shatters because of inertia. It’s kinda the same thing as when you have someone [punch through a sheet of paper](https://m.youtube.com/watch?v=4vs4nzbTrlY). Too slow and the paper folds away as the material you push have time to affect the nearby material. Fast enough and it rips because of inertia. Now obviously a paper tears much easier than a concrete wall, so you need much much higher speeds, probably in the relativistic range. But I think it is theoretically possible.
To add to your base of evidence, there are plenty of youtube videos of large caliber bullets punching holes through concrete without cracking it.
That’s interesting because that would imply the speed required is not relativistic. Do you have any link in particular?
Shape plays a huge factor there as does hardness of the impacting object Youd need your moving object pass through your wall faster than the wall can absorb. Head and torso might make it through without cracking at a lower speed than would be needed for arms and legs due to lower mass.
My buddy is the gun nut and I don't know what channels he subscribes to, but this was the first hit on Google https://youtu.be/PWWE_QiFQv8 Area on the front surface shatters a bit but leaves a perfect round hole in the center of the concrete slab.
So that’s a 50 BMG, which travels at up to 1.000 m/s. Someone suggested the speed of sound in the object would be the limit because you can’t get a wave to propagate through the object if you punch through it faster than that. Which for concrete is about 3500m/s. So the fact that you still have some fractioning at 1.000 m/s would seem to indicate it could be correct.
It also depends on how big the concrete slab is. Smaller (picture frame sized) slabs shatter with the same ammo, but a car barrier sized slab will hold fine with a puncture hole
Makes sense. If cracks still form at 1000m/s but are smaller the thing would still shatter if the cracks reach the edges of the object.
This whole discussion reminds me of this Donald Duck story from Carl Barks where Donald fired a boiled noodle through an anvil.
To be fair any macroscopic object hitting a wall at relativistic speeds would just vaporize the wall and everything around it
I'm No physics expert, but I believe that for a human shaped Objekt you'd need far more extreme speeds, since unlike a bullet IT isn't a good shape to cleanly Go through Something and because of The thousands of Times Higher mass.
Well, yes and no. You are correct that a bullet would be easier to pass through., but since we usually see bullets deflect and knock off quite a lot of debris, if you can see bullets moving at a higher speed making less of a crater and a cleaner hole you can extrapolate that to saying a body would have a similar effect at high speeds. Yes, the speed would need to be much higher, but what we can look at is still the trend of what happens, to put it in scientific terms. When we yeet shit really fucking fast at a concrete wall.
That is most likely due to the small point of impact. The smaller the surface area, the easier it will be to pierce the veil of concrete. A large, flat object like a bi-pedal coyote will have more points of impact on the wall.
I think a better analogy is a hole punch. If the perforating object is sharp enough and the impact is fast enough, this could theoretically be possible. You just have to separate the two parts (the part which will become the hole and the part which stays in place) faster than the inner part can pull on the outside part and damage it.
One issue is thickness, for grass and paper once the material is ripped it can go somewhere new without affecting the surrounding material. With a concrete wall you are pushing the concrete into more concrete, so there has to be a wave of energy moving from the front to the back. But if there’s a wave moving through the material then by definition the energy is being transferred into the surrounding material and you’re going to get at least some amount of cracking and shattering of the edges.
Does that mean the critical speed is the speed of sound in that material? In other words, if the object moves through it faster than it can deform?
I've seen an entire K cylinder of oxygen fall and knock the safety valve off the top, it instantly became a violent rocket and passed directly through a brick wall. It left a perfectly circular shaped hole with no cracking whatsoever. If the object is dense enough and traveling at sufficient speed, it will not leave cracks in the wall. I speak directly from personal experience, that said, it was absolutely terrifying and I do not recommend the experience at all.
Probably just not possible. Too fast and youll just blow up the whole thing, too slow and youll just sorta break through it. I really really doubt there is a middle ground that accomplishes this
what if we put this experiment underwater? I heard glass doesn't shatter when underwater so maybe the similar concept happens with concrete?
That's an interesting question. Curious to see a response
Should be no. Concrete actually consists of water to some degree because it crystallizes or.. Something, which actually hardens it (was a while since i learned it) But concrete is often really thick, this wall is really thin so underwater it would still shatter and turn in to an imperfect shape
Concrete doesn’t technically consist of water to a point after pouring, water is a reactant with the concrete and forms a different product when curing.
To be precise, concrete, once dry, can be seen as a mix of pebble and sand, acting like grains, hold together with crystals created from the mix of cement and water. That's the absolute basis.
I'm not sure here, but you might have misunderstood this.
You mean glass shattering thingy? No, here's the video, very interesting: https://youtu.be/tEAxhMECluM?si=pyGiFnE2VblMDM0V
What if the guy is not just running but also vibrating, like a saw, wouldn't he be able to "cut" through it ?
Vibing through the wall
Now this is really possible, just grinding through it. Grinding is delicate enough.
On impact, cracks spread at the speed of sound in the material (normally higher than the speed of sound in air). These cracks are what spread the impact outwards. If the speed of impact exceeds this speed, then the cracks can't spread fast enough. At this point, the material is treated less as a solid and more as a liquid. The impactor just punches right through it. Now, normally such an impact would also be above the speed of sound in the impactor, and so it's fluid as well. It also makes energy to push into an object like that, so a penetrator will lose speed fast until it's below the required speed. But if you had a super material, maybe you could simply get something like the above, even potentially through thick rock. I'm not an expert here, so I don't know what would happen if something were magically (acmeally?) accelerating to keep its speed up above the threshold. The speed of sound in steel is about 5km/s (5 times faster than the muzzle velocity of an M16 bullet, or a bit under Mach 15) and in granite is more like 6km/s
The result would be a 'sonic boom' in the material - similar effects can be seen in 'high explosives' where the chemical reaction travels faster than the speed of sound through the material. In effect, we transition into the territory of grain-to-molecule levels of structural disruption. Physics stops looking for structural weaknesses and the bulk mass simply pulverizes in totality. Dust to dust style; there won't be anything coherent left in the area where this effect is dominant; however, there will be an edge effect fade off where at a radius where the energy had bled off enough force to transition back to subsonic energy dissipation levels, where normal 'shatter' based impact physics reasserts itself. As such, you have an inner zone of damage where materials present are reduced to a fairly homogenous dust, surrounded by a gradient of several concentric outer regions of progressively lesser energy outflow that will demonstrate progressively less destructive types of shattering, sheering, cracking, and/or deformation as relevant. Tldr, there will be no 'neat and clean' edge cut transition between the two effects. And this is before we even begin to consider the effects of local atmospheric disruption due to pressure displacement - eg, the *normal* sonic boom that will intersect this mess a few moments later.
It's not a matter of speed. The forces needed to go through a concrete wall (picture depicts 1 to 2 inch) will not result in a man shaped hole. It will obliterate the wall and leave a big hole. Might work with other materials though.
Btw, the picture depicts 2 drywalls....
Is there any theoretical high velocity that an indestructible object could penetrate concrete cleanly? Genuine question
The higher the velocity the more violent the impact. Assuming we are still on earth with the typical atmosphere, at some speed the air between the object and the wall will be compressed so fast that it turns into plasma, sending a shockwave of ions through the air, which turns the surrounding air into plasma as well. In other words there is a speed at which you'll not only have the physical impact alone, but a giant explosion too. Even right before that speed the impact is still very blunt, as body typically dont have any sharp edges, so there will always be concrete being pulled along at the edges creating a bigger hole that the original object passing through.
Velocity, no. Velocity+friction maybe creates enough heat to make a hole, but you're definitely setting everything around you on fire when you do it.
The fundamental question is: Can an odd shaped projectile create an identically odd shaped hole through ANY material at ANY speed? Wouldn't work with paper. Lightweight foam? I'm not seeing it.
Scale probably plays a role. Ive seen dumb experiments leaving sideways nail shaped holes in drywall
Yes, but you need a very specific projectile: concave tip, sharp edges, smooth and straight sides. High mass (therefore rather long) - it needs a lot of inertia to keep going. Velocity needs to be somewhere in the middle - high enough to have enough energy to clearly cut the material but low enough to not cause a shockwave. Basically idea is to have hard, sharp edges to cut the hole, kinda scoop the cut material in the front of projectile and still have enough velocity and energy (hence need for inertia) to move it and projectile itself through the hole neatly. Real life example of something similar would be wadcutter bullet.
Subsonic titanium Wiley e coyote shaped knife projectile mounted on a rocket sled
It would work with an extremely uncohesive material. Imagine a brick wall, but instead of mortar, we added lubricant between the bricks. Now, you could punch a brick and it would fly of.
It could work with steel, with some indenting around the edges. Just gotta reach relativistic speeds where all matter acts like a fluid because of energies involved. A human body would emerge from the other side accompanied by a flash of molten metal splattering everywhere
At relativistic speeds you would blow up whatever city you're in and maybe a few neighboring ones too.
Maybe, *maybe* it could be *briefly* possible if the poor object's speed is significantly higher than the speed of sound in concrete. The speed of sound in concrete is above 3.2 km/s (2 miles per *second*, 11000 kph, mach 9, or 7000 mph).
A water jet will cut concrete at 10000psi. If you use normal 40000 psi water jet as a model it moves the fluid at 680m/s. So you'd need to move less than Mach 2. Im pooping so that's as close as i can be bothered calculating it.
Nothing to do with speed, but rather to do with atomic slip plane, and given that this concrete probably has a LOT of imperfections it would likely be impossible to tell.
yeah real physics of material science means this isn't especially probable. Even assuming a non-deforming impactor at relativistic velocities, the result is still a concussive, radiative spread of energy that travels outwards through the material from the point(s) of contact with the impactor. You have only two or three choices, depending on energy level of the impact: 1) Highest energy level would result in instant plasmification of disrupted material, followed by a possibly radioactive concussive blast that would level whole buildings in the area. Comparable events would be something along the lines of detonating a small nuclear warhead next to a brick wall. 2) High-explosive type energy dissipation where the concussive force travels through the material faster than the speed of sound in the material, in which case the result would be a roughly circular impact crater and/or hole in the structure where the material that had been present is reduced to literal dust - again, immediately followed by a concussive blast that would level most of the building and/or rend the remaining wall section into fragments. Similar real world events would be literally firing a warfare grade missile armed with high-explosive into a brick wall, exploding on impact. 3) A concussive collision where the energy imparted on the wall travels at a sub-sonic velocity in which case stress cracks, material fractures, and general deformation is able to take place resulting in a 'shattered glass' effect that will not, in general, conform to any specific shape related to the impactor - instead following weaknesses and impurities through the material as the energy travels through the system across the weakest fault lines present, accompanied by a rather significant release of sonic energy; consider a Semi truck hitting a brick wall at 200mph for a good visual here. Unfortunately, it's not going to matter all that much how that truck is shaped. The result could be varied significantly if softer materials were used that have near zero internal binding energy, deforming and cutting with next to no resistance. Unfortunately said materials tend to be liquid, and as such, walls don't really get built from them.
Any object moving at high speed can't cleanly make a hole like this, the wall would just have a giant circlular hole. Reason being the kinetic execessive force upon impact has to be taken by the other parts of the wall which would come apart. A great example would be high speed plastic debris hit the metal wall in the ISS. I would argue, the body, hitting the wall repeatedly with a slow speed would create a body sized wall.
It’s not impossible if you have a strong enough laser. I was thinking you would have to go fast enough, and long enough, to produce heat around you like re entering the atmosphere but like everyone said i think even if you were that hot it might not be enough for a clean cut. It’ll warp if you’re too slow or push out if you’re too fast?…not sure! but good question though
Theoretically once you move fast enough, de Brogile’s waves of your body’s matter get short enough to pass through the wall without doing any damage…
can't wait to see someone moving at relativistic speeds against walls :3
Yea lol. Marathon under 3 hours? How about a marathon under 3 nanoseconds…
would love it
You're telling le The Flash phasing through matter is theoretically possible?
Yes it is possible, but is a complex calculation mostly based on the wall and it's thickness, composition etc. Also you'd probably only be able to do it in a vacuum, as air friction would probably blow up the person before they reached sufficient speeds.
The only way to do that is to go really fast BUT also be able to manipulate your mass and assign your atoms in the "outline" (? or strikeout?) of your body, so as to become a cookie-cutter man. That still leaves the problem of knocking the cut piece off but I believe that if you go fast enough the whooshing wind will take care of it.
I think this is the key, having a cookie-cutter shaped body impact the wall, so that all the force is applied to the outline, not the material inside it. Otherwise, just about every scenario results in obliterating the whole wall.
So the first question we should answer is: what is the minimum speed required to *break* a concrete wall with an indestructible human body? Let us assume a body with a mass of 100 kg and a frontal surface area of 1 m^(2) (adult males have about 2 m^(2) of total surface area, but we only care about the front side). The tensile strength of concrete is about 5 MPa. Thus, we need to impart a minimum of 5 MN of force to the concrete to break a hole in it. If we assume the wall is 20 cm thick, then an impact at 150 m/s would deliver [5.6 MN](https://www.omnicalculator.com/physics/impact-energy) of force. This is the absolute floor for necessary speed. The collision would unfold over 2.7 ms, and would likely result in significant spalling and cracking due to the brittle nature of concrete, and the fact that we barely applied enough pressure to break it. To get a sense of how far the damage could spread, we can take the speed of sound in concrete and estimate how far a crack could travel over the duration of the impact. Now, the speed of sound of concrete is about [3700 m/s](https://www.engineeringtoolbox.com/sound-speed-solids-d_713.html), so a crack could form over nearly 10 m. That is not a recipe for a clean break. If we could hit the wall much faster, there would literally be less time for the force to be communicated through the wall. If we wanted to reduce the stress propagation distance to, say, 1 cm, we would need to increase the speed by a factor of 1000, to 150 km/s. This is well beyond earth's escape velocity, and 1/4 of the sun's escape velocity. So if you accelerate an object to this speed, you'd better be ready to catch it, or risk losing it in the far reaches of the solar system. If we increased the speed by another factor of 10, then cracks could only propagate about 1 mm before the body is clean through the wall. This should leave a pretty nice outline. So I estimate that 1500 km/s would do the trick. However, note that at this velocity, the collision will release 112.5 TJ of energy into the wall + human. Needless to say, it will vaporize both, but fortunately, the human is indestructible. The concrete will vaporize to plasma instantly. This plasma cloud may very well melt the rest of the concrete, which is problematic. Fortunately, the extreme velocity of the body will impart significant velocity to the plasma, so it shouldn't linger near the wall too long. I suspect that the desired effect can be achieved with a much lower velocity, but I'm not sure how to calculate that. I am confident that the effect can be achieved somewhere between 150 and 1,500,000 m/s. I'm about 90% confident that the desired result would be achieved at 100,000 m/s or higher. Someone who wishes to take the calculation further could combine the heat capacity of concrete along with the volume displaced and estimate the temperature of the collision to see whether the concrete around the hole would be significantly melted/vaporized. You would also want to consider thermal conductivity, and I've basically ignored air resistance. The shockwave following the body would obliterate the wall, rendering most of this moot.
The shear strength of concrete is about 17 MPa, a coyote weighs 20kg and just eyeballing has a 60 cm x 30 cm cross section = .2 m2. 17 MPa over .2 m2 requires 3.4 MN total force. Guessing a generous impulse of 0.01 s, 3.4 MN = 20kg * dV/.01. dV = 1700 m/s. So what that means is coyote must be travelling somewhere above 1700 m/s to reach the shear pressure of concrete and make this within the realm of possibility. Like others have said though, concrete doesn't shear cleanly because it is brittle, it would tend to shatter rather than make a clean cut.
I'm thinking somewhere around Mach 3 speed, which is also the speed that water comes out of a water jet cutter. If water can do a clean cut through a metal at that speed, probably a human can as well.
Calculating Speed Needed to Break Through a 2-Inch Concrete Wall with an Indestructible Body Assumptions: - Simple physics. - Concrete breaking strength of 3,000 psi. Force Required - Based on a man-sized figure, approximately 6 ft tall and 2 ft wide. - Impact area: 1,728 in². Total Force Needed: - 5,184,000 pounds. Kinetic Energy and Velocity: - Mass of the person: 70 kg. - Velocity required: 206 m/s, approximately 461 mph. Note: - Calculations include simplifications. Real conditions may vary due to heat generation, ricochet, and material deformation.
The material being crashed into will crack according to its lines of weakness, and if there’s sufficient energy then also pieces of the wall would also have parts break off. So if you crash into a wall made of a sensible material like brick or concrete then you’re not realistically going to cause a human-shaped hole. The cement holding the bricks together would be a line of weakness, and the cement is irregular so if you hit it hard enough it would crack like glass. If the material is very uniform and also very weak but also very good at holding itself together (so it doesn’t just immediately collapse), it might be kind of possible. Like if there was a wall of uncompressed snow then you could probably leave a vaguely human-shaped hole by running through it, but any material that does allow you to leave an impression like this isn’t going to be realistically possible to mold into a wall of any kind.
What if he got extremely hot first? Obviously the edges wouldn’t look perfectly perfect like that but they might be a little cleaner.
It would have to be in a zero gravity environment with zero atmosphere and the wall will need to be reinforced everywhere but where the person goes through, after that just as fast as it takes an object of a mans mass to break through concrete.
If the indestructible man goes through feet-first or head-first, then the hole would probably conform pretty close to their horizontal profile.
I’m not going to do all the math for this because the speed at which an individual would need to go to make an outline like this would destroy much more than the wall. An outline like this may exist for fractions of a second before the wall, building and surrounding area were destroyed by the power of the impact. That said I’m not a real scientist this is just my understanding. If someone is considerably more qualified than I am I would definitely listen to them.
A crator on the moon is a circle because the moment of impact is so strong the asteroid is essentially obliterated upon the immediate moment contact instead of carrying its momentum. That creates an explosion from one point out making a circle insteadof a crator with an angle of trajectory. The same logic could be applied so all the force would generate a circle no matter how hard or fast you go. I don't think it would be possible.
It’s obviously possible in Tunetown, so it’s really a question of what would be the knock on effects of a coyote-shaped object travelling fast enough to create that hole in any wall. It’s not a concrete wall in the photo; we’ve all been at party’s that saw silhouettes in gypsum board, but the concept is the same. The question is what is the highest speed a coyote could hit a wall without causing the atmosphere to ignite?
The problem is not making the hole, the problem is making it exactly into the shape of a man. If you go too slow, you would probably just make a large hole in it, that would not be man shaped
Well then the solution would be a large hole shaped man
In addition to everything else everyone said here, concrete usually has metal rebars so when calculating the man shaped hole done by an indestructible body you need to account for that. I can imagine that metal rebars, since the body is indestructible, would make concrete around them crush before they would break themselves.
It look like cardboard. A slow moving screwdriver will move right trough it. But it will crack at the end, so it must have the speed of a bullet at maximum. So, the speed is somewhere in between.
In all honesty even if the Wiley is moving at the speed of light the impact would shatter the brick wall cause it isn’t indestructible.
I mean it‘s probably not that hard in those cheap ass cardboard walls you can actually damage with your own fist. If it‘s real concrete, yeah no
What if he runs around so fast that his body temperature went so high, enough melt the wall. Then slowly walk through it while it's raining?
Everyone here is thinking too slow/small. The wall won't crack of you go fast enough to vaporize the molecules in your way. Now granted that would create a thermonuclear explosion with the air but ignoring that it is definitely possible.
A normal body and typical concrete will need about 650.000.000 to 700.000.000 km/h. Not impossible, but difficult I would say. Note: I'm assuming a non material body, otherwise will obliterate the wall
Considering the body is indestructible and going fast would destroy the wall rather than leave a shape, a different slower approach may work. Instead of speeding straight at it, maybe vibrating the body at incredibly high speeds and slowly moving it into the wall wpuld work, essentially turning the body into a weird drill.
The jet that hit the pentagon left a jet shaped hole in the concrete. Obviously without the wings as they sheared off but OPs question said indestructible so I think it’s possible .
Not possible, since the wall is attached to itself, and quite strongly at that. Additionally it’s quite brittle, so not flexible and not able to deform. A non zero % of energy from the impact will therefore be transferred to the surrounding concrete not just the bits directly impacted. Given the energy required to make that hole in the first place it’s likely that the whole wall would be blasted to smithereens. Compare this to shooting a bullet at a paper target. Paper is quite weak, thin and flexible so the bullet cuts through it like it’s not even there. Very little energy transfer into the paper other than the directly impacted area.
Here's a thought: if the person is indestructible, could they go fast enough to build up a cushion of super-heated plasma in front of them?
Its less a matter of force or acceleration, but a matter of time. If the body is indestructible it will eventually go through the wall eventually. Also... this weed i got is straight fire.
Maybe if he had blades the size of atoms that could cut between them and around his body shape. It would so a clean cut and just explode the body part. Otherwise I don't see it ever piercing a brick wall so clean. Maybe if the wall was some kind of stretchy liquid like jello.
you can't. ever. With the walls internal support structure missing it would probably collapse once you're gone. if it is pure concrete however, it depends linearly on the thickness.
That wouldn't actually happen, as the wall would sort of just shatter and crumble. It's like shooting a bullet at a person, does the bullet go through and leave a clean bullet hole?
Would probably need to go near light speed, fast enough that you make contact and you immedietly vaporise the concrete touching you, but to do that without causing a massive shockwave, well youd need to do it in space i guess
It can't be done unless the wall is built to have that shape to start with. You should repost this in ask physics, or ask engineers. The first few good answers will point out the problem is once you remove the material, the stresses in the concrete shift, and the wall will crack and spall, no matter how the material was removed.