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Hmmm... ok. Would something like
suffice?
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Common Calculation Concerns: Skull Crushing and FTE Movement
- Thread starter Wokistan
- Start date
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I think so
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No it doesn't. It divides the mass of a skull by bone density to get a volume. Where is it being treated as a cube-shaped bone?
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Now we just need to deal with the skull-crushing debacle.
Though DT has already said he isn't skilled in that regard so we're just stuck on that part.
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KatBoi said he was gonna do some work on the area of the piston used to crush the skull once he got back from vacation but other than that the only people I really know of that can handle this type of stuff is prolly Spino.
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Did I? I thought we shifted to your dimensional analysis solution and I was going to check the math.
Either way, the SI for that paper does not contain the crushing machine schematics, so I would have to pixel calc the piston's size from an image in the paper to get the surface area the force was applied over.
That whole process sounds a little less elegant than what you came up with, to be honest.
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I found another value here which says 1200 lbs.
I'll just use the same formula.
For comparison's sake I'll assume the Japanese researchers mean the value in psi.
1200 psi= 8273709 pascal.
Skull top area= 0.03 meters^2 (Based on multiplying the length and width of the average skull I found here and here (Second link you should look for "Head Breadth" and "Glabella to back of head". The values are roughly 15 cm width and 20 cm length. 0.15 m and 0.2 m respectively. 0.15*0.2= 0.03 m^2)
8273709*0.03= 248211.27 newtons
Skull height= 0.22 meters
Calc (Work= force times distance): 248211.27*0.22= 54606.4794 J (Wall level)
I'll just use the same formula.
For comparison's sake I'll assume the Japanese researchers mean the value in psi.
1200 psi= 8273709 pascal.
Skull top area= 0.03 meters^2 (Based on multiplying the length and width of the average skull I found here and here (Second link you should look for "Head Breadth" and "Glabella to back of head". The values are roughly 15 cm width and 20 cm length. 0.15 m and 0.2 m respectively. 0.15*0.2= 0.03 m^2)
8273709*0.03= 248211.27 newtons
Skull height= 0.22 meters
Calc (Work= force times distance): 248211.27*0.22= 54606.4794 J (Wall level)
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So it seems like we have two separate sources saying 1100-1200lbs to crush a human skull, so we're at a point of making sure we have a sound way to get an energy value out of that, yeah?
Based on the method above, we are calling skull crushing at about 50x the high end of a professional boxer's punch (1000 J, based on some googling). As a common sense check, this seems like the math above is giving us a reasonable energy output for splattering a skull. This would also be the energy equivalent to shooting someone multiple times in the face (also in line with skull destruction).
I wish I had the expertise to judge if this calc is physically sound, but I'm just bad at classical mechanics. So as I see it, the only issue we could be running into is, "right answer based on the wrong math" imo.
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Honestly I myself am not sure, since the values say lbs instead of psi.
I have seen evidence for shotgun slugs blowing up heads but that was usually at the second shot made at point-blank as the first shots tended to be from a distance.
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Yeah lol, hence the caveat at the end. My barrier here is that my physics background is all related to chemistry. I have zero structural/mechanical engineering experience.
Edit: In response to your edit, I'd need to look up the speed and weight of the shot that scatters from a shotgun to get a KE value. The comparison I was making was to a single shot from a handgun.
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I was mostly talking about solid shotgun slugs. Mostly based on this vid I recently found.
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bump
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To deal with the calc for skull-crushing.
Honestly I'm at a halt here. I've run out of all alternative options.
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AFAIK Spino did say he knew some values for skull-crushing but he's been busy as of late.
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1100 pounds is what I've used in the past which seems in line with what is found above
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This is a striking force right? Does that translate into striking energy and how so? (And lifting strength too?)
And... Your source for such data?
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It says pounds of force but I'm pretty sure the crushing tests definitely did not involve a rapid strike, they themselves state to have mostly involved compressing the skull like in most hydraulic crushing videos you see. And as the above comments discussed, the values were gotten by compressing the weakest parts of the skull.
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Basically, TL;DR...
This (520 lbs or 2300 newtons, second link is the OG source of the 520 lbs value for skulls which the news articles took, but the problem is, this is for an unprotected child's skull and it's for bike helmets used by children, this is not the value for the skulls of adults)
This (This states a slightly higher value of 3492 newtons or 785 lbs Ignore that, there is a higher value of 550 kg and the link explicitly states it to be carried out in the way of compressing the skull at the bitemporal direction AKA side of the head, but then there's another problem, this is for fracturing the skull at its weakest points at the temporal lobes, and it's only for fracturing, not for complete catastrophic failure where the entire skull gets shattered)
This and this (second link's archive.vn link here because paywall) (As it turns out, the 520 lbs number was later corrected to 1100-1200 lbs of force based on the above pubmed NBI article in the second link. It also mentions another value for the skull's maximum pressure limit, 6.5 gigapascals)
This (Reddit link but apparently its true source is Fight Science National Geographic, where apparently in one episode they stated that one dude could easily survive being struck in the head with 2100 lbs of force whereas other peoples' heads would shatter, which tells me that not all skulls are the same)
The Pubmed, WashingtonPost and MaineNews online links are likely the most accurate with the Pubmed outright stating that the test was carried out via compressive strength and Maine News article also supports it being that way, outright stating that you need 1100 pounds of PRESSURE to carry out the act. Meaning psi is prolly the proper unit for these crushing tests.
This (520 lbs or 2300 newtons, second link is the OG source of the 520 lbs value for skulls which the news articles took, but the problem is, this is for an unprotected child's skull and it's for bike helmets used by children, this is not the value for the skulls of adults)
This (
This and this (second link's archive.vn link here because paywall) (As it turns out, the 520 lbs number was later corrected to 1100-1200 lbs of force based on the above pubmed NBI article in the second link. It also mentions another value for the skull's maximum pressure limit, 6.5 gigapascals)
This (Reddit link but apparently its true source is Fight Science National Geographic, where apparently in one episode they stated that one dude could easily survive being struck in the head with 2100 lbs of force whereas other peoples' heads would shatter, which tells me that not all skulls are the same)
The Pubmed, WashingtonPost and MaineNews online links are likely the most accurate with the Pubmed outright stating that the test was carried out via compressive strength and Maine News article also supports it being that way, outright stating that you need 1100 pounds of PRESSURE to carry out the act. Meaning psi is prolly the proper unit for these crushing tests.
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Quote source where it says "Skull top area= 0.03 meters"
And since we have a few value sets for skull crushing, we are yet to choose one most appropriate
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I calculated it based on the length and width of the average skull I found here. The link says the skull is 15 cm wide and 20 cm long. Matches the wikipedia head size values here, 1 (Head breadth) and 7 (Glabella to back of head) are our main numbers there.
20*15= 300 cm^2 or 0.03 m^2
I forgot to add the m^2 in my original comment and the length sources. Fixed now.
1100-1200 lbs value was decided as the most appropriate. Sources here, here and here (Archive vn link here). The first link explicitly mentions compression being used, and the second link outright says "1100 pounds of pressure", which can't mean anything other than compressive strength or PSI.
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DontTalk already handled the Faster-than-eye portions of the CRT.
Now only the skull-crushing portion remains, which DT has said he doesn't have enough experience on.
Wokistan
Bioluminescent African American Working At The CIA
VS Battles
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Calculation Group
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- #156
I think the people trying to calc skull crushing at above 9-C are kinda missing the point.
In real life fields of science, when you do all your math and the result ends up with something different, then that's just a problem with your math. You can't really throw away what actually happened, so something must be wrong with what theoretically should have happened. Empirical testing trumps hypothetical math, every time.
I've already demonstrated with a very generous calc that even the heaviest elephant ever under rather wankish conditions flat out cannot be 9-B, and elephant skull crushing is rather well documented and certainly was not constantly using 10k pound elephants. We know from historical testing, then, that skull crushing can be done at sub 9-B amounts of energy output. As such, any calcs that contradict this without finding some issue there first are just kinda wrong by default, because testing always beats numbers.
I'd said that I couldn't find a good way to calculate it myself, but could find stuff to show that it couldn't be 9-B. Maybe someone else finds a better way to calc it, and we have a better value than >1072J or whatever the world record punch is rn. That would be neat, and more power to you if you find a way to do that, but if you run the numbers and come up with a higher minimum value than what we know really did accomplish the job in reality... it's just incorrect.
I really do think that all we can do in the meantime is just put it as a vaguely superhuman 9-C.
In real life fields of science, when you do all your math and the result ends up with something different, then that's just a problem with your math. You can't really throw away what actually happened, so something must be wrong with what theoretically should have happened. Empirical testing trumps hypothetical math, every time.
I've already demonstrated with a very generous calc that even the heaviest elephant ever under rather wankish conditions flat out cannot be 9-B, and elephant skull crushing is rather well documented and certainly was not constantly using 10k pound elephants. We know from historical testing, then, that skull crushing can be done at sub 9-B amounts of energy output. As such, any calcs that contradict this without finding some issue there first are just kinda wrong by default, because testing always beats numbers.
I'd said that I couldn't find a good way to calculate it myself, but could find stuff to show that it couldn't be 9-B. Maybe someone else finds a better way to calc it, and we have a better value than >1072J or whatever the world record punch is rn. That would be neat, and more power to you if you find a way to do that, but if you run the numbers and come up with a higher minimum value than what we know really did accomplish the job in reality... it's just incorrect.
I really do think that all we can do in the meantime is just put it as a vaguely superhuman 9-C.
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Just for the record crushing a concrete block is about 350 J
Wokistan
Bioluminescent African American Working At The CIA
VS Battles
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- #159
Seems better than nothing, at least. It doesn't exceed the elephant thing but also doesn't let people be like "hmm this technically is calcless so it is 300 joules."
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I think 300 joules is not too far off. The video I linked above shows it only takes 350 joules to crush a small cylindrical block of reinforced concrete. And something tells me that a human head is even less durable
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