Infection / Destruction / Hope

The 3rd and final Morningstar Saga book, SURVIVORS, is now available for pre-order here!

The Morningstar Saga
Register  |   |   |  Latest Topics
 
 
 


Reply
  Author   Comment   Page 1 of 2      1   2   Next
Z

Avatar / Picture

Ah'm yer huckleberry
Registered:
Posts: 4,599
Reply with quote  #1 
In this case, the bodies are those of zombies.

Okay, I had a debate with a reader a while ago via email that just popped back into my head and I'd like to hear some other folks' thoughts on it.

The question is thus: when a round impacts a body, what is the physical effect? I don't mean the damage it does--I mean, when it imparts its kinetic energy, what does the body do? Simply fall? Spin? Get knocked off its feet?

I gave it some thought, and here's what I came up with:

It depends on two things: where the round strikes, and whether it passes through the body or lodges in it.

My opponent's stance was that all bullet wounds cause a body to simply slump in place, whereas my opinion was that under certain conditions a body could be knocked backwards or spun in place.

For example, if the bullet strikes the shoulder and lodges in the bone, the body may do a 45-degree spin before falling. If it hits center mass and lodges, the victim may be knocked back (caliber-dependent--I wouldn't expect a .22 to do that.) If the round hits and simply zips through the flesh, it would still retain much of its kinetic energy upon departure, allowing the body to simply fall without reacting otherwise.

My thought was that since bullets have relatively high kinetic energy, that energy isn't simply going to disappear when the round lodges in bone or flesh. The energy is transferred to the body, right? So if the round stops--and transfers its energy--I'd expect the body to react accordingly rather than simply slump in place.

Your thoughts?


__________________
"'Peace on Earth,' was said. We sing it, and pay a million priests to bring it. After two thousand years of mass, we've got as far as poison gas." -Thomas Hardy

"Buy the ticket, take the ride." -HST
Suicidalpoptart

Carrier Chow
Registered:
Posts: 3
Reply with quote  #2 
If you mean that zombies will react to bullets like being forced back by the power of the bullet, then i agree. I also think that zombies would probably fall to the ground if a bullet were to hit their spine, as would any animal.

__________________
"They're coming to get you Barbara!"
Unholyevil

Avatar / Picture

Loyal RCS follower
Registered:
Posts: 1,881
Reply with quote  #3 
A bullet hitting even a shoulder will not cause a dramatic spin.  It all depends on the bullet as well, a hollow point which is made to deform on impact to cause more blunt trauma will have a much different effect than say a FMJ bullet designed for penetration.  Mythbusters did a test seeing if the human body would actually get blown backwards when shot, like in the old wild west movies.  Even with a 12ga deer slug, the body simply fell backwards, no flying/launching back.  

The human body is quite resistant in its design.  Skin is very flexible, and if you ever watch someone take a punch to the stomach in super slow-mo you can see how the kinetic energy is dispersed.  A bullet would have a similar effect, only with more penetration behind it.  Put it this way, a professional boxer can hit with over 1000 Joules of force, over 1 ton of force.  A 9mm bullet has a muzzle kinetic energy of about 550 Joules.  Quite a difference eh?

Z, I mainly have to disagree with you.  If a human body is hit with a bullet, whether it be a .50 BMG or a 9mm, it will not be forced backwards a considerable amount, it will simply slump backwards/fall.  This statement is key to this arguement: for every action, there is an equal and opposite reaction.  So if the human body shot with the .50 BMG was sent backwards 2 feet due to the kinetic energy of the round, the shooter would also have to be sent backwards the same amount.

__________________
jake1100

Avatar / Picture

Veteran
Registered:
Posts: 1,451
Reply with quote  #4 

myth busters busted that one. And yeah it would fall if you shot it in the spine, but thats not really a kinetic force fall, its just a drop because of a severed spine. On myth busters they hung the body of a pig from a hook that was barely hanging on to a bar, they barely had to push it to make it fall. But they fired on it with a full auto thompson and an MP-5, the pig didnt fall. I think Newton's law about equal but opposite reaction applies


__________________
"Legal" and "illegal" are fuzzy gray areas for me.

I go with "moral" and "immoral" instead. Those are usually pretty clear-cut.

-Z
jake1100

Avatar / Picture

Veteran
Registered:
Posts: 1,451
Reply with quote  #5 

oh and they used a 12 guage deer slug on it, still no cookie.


__________________
"Legal" and "illegal" are fuzzy gray areas for me.

I go with "moral" and "immoral" instead. Those are usually pretty clear-cut.

-Z
jake1100

Avatar / Picture

Veteran
Registered:
Posts: 1,451
Reply with quote  #6 

unholy, you are officially the coolest girl...ever.


__________________
"Legal" and "illegal" are fuzzy gray areas for me.

I go with "moral" and "immoral" instead. Those are usually pretty clear-cut.

-Z
Unholyevil

Avatar / Picture

Loyal RCS follower
Registered:
Posts: 1,881
Reply with quote  #7 

Where is all this girly talk coming from?  I am a lycanmutt according to Hobbit man.  Last I checked I think I was a dude, will you check again for me?

Edit:

why did my text get bigger/bolder?


__________________
Z

Avatar / Picture

Ah'm yer huckleberry
Registered:
Posts: 4,599
Reply with quote  #8 
Quote:
Originally Posted by Unholyevil
A bullet hitting even a shoulder will not cause a dramatic spin.  It all depends on the bullet as well, a hollow point which is made to deform on impact to cause more blunt trauma will have a much different effect than say a FMJ bullet designed for penetration.  Mythbusters did a test seeing if the human body would actually get blown backwards when shot, like in the old wild west movies.  Even with a 12ga deer slug, the body simply fell backwards, no flying/launching back.  

The human body is quite resistant in its design.  Skin is very flexible, and if you ever watch someone take a punch to the stomach in super slow-mo you can see how the kinetic energy is dispersed.  A bullet would have a similar effect, only with more penetration behind it.  Put it this way, a professional boxer can hit with over 1000 Joules of force, over 1 ton of force.  A 9mm bullet has a muzzle kinetic energy of about 550 Joules.  Quite a difference eh?

Z, I mainly have to disagree with you.  If a human body is hit with a bullet, whether it be a .50 BMG or a 9mm, it will not be forced backwards a considerable amount, it will simply slump backwards/fall.  This statement is key to this arguement: for every action, there is an equal and opposite reaction.  So if the human body shot with the .50 BMG was sent backwards 2 feet due to the kinetic energy of the round, the shooter would also have to be sent backwards the same amount.


Duly noted, but if I were hit by a professional boxer at half-power, I'd probably still get knocked down.

Re: equal and opposite: the shooter does absorb significant recoil with their shoulder, and the weapon absorbs some, as well. What I can't figure out is where the kinetic energy goes. The shooter feels the force being applied to them, but apparently the target does not--it simply falls. What happened?

The shooter's shoulder is rolled back, the weapon jumps backward, but the person on the other end doesn't react at all? I find that very interesting. It's like the round's kinetic energy ceases to exist, which is, of course, impossible...

I'm not saying you're wrong. Of all the possible people I might listen to, the Mythbusters rank near the top. Just pointing out a few things.

Set up a tin can and blast it--it'll go flying. That's proof of concept right there. If there was no movement imparted to a target from the round, the can would always stay sitting on the post. It would just wiggle a tiny bit as the round went through it. But it doesn't--the round imparts kinetic energy and the can goes flying in roughly the same direction the bullet was moving. Same principle--what makes a human body different from the can? I'm not saying a human being or zombie would go flying through the air, but I also just can't buy the idea that it won't be moved at all when struck. It's heavier, and it would move much less, but the movement's gotta be there. The physics just don't make sense without it.

By the by, if you agree that a body can and will fall *backwards* when struck, then you're actually agreeing with what I'm trying to say. Bodies fall forward naturally--if they fall backwards, they've been pushed by something.

I'm not talking Hollywood style Matrix bullet hits, where people are lofted up and off their feet--but I do think there's enough force at work to cause a noticeable physical reaction if the round lodges.

I saw a great video of a sniper taking out a guy holding a hostage--the round snapped his head backward, and he fell on his back. That's the kind of movement I'm talking about.

__________________
"'Peace on Earth,' was said. We sing it, and pay a million priests to bring it. After two thousand years of mass, we've got as far as poison gas." -Thomas Hardy

"Buy the ticket, take the ride." -HST
Z

Avatar / Picture

Ah'm yer huckleberry
Registered:
Posts: 4,599
Reply with quote  #9 
Quote:
Originally Posted by Unholyevil

Where is all this girly talk coming from?  I am a lycanmutt according to Hobbit man.  Last I checked I think I was a dude, will you check again for me?

Edit:

why did my text get bigger/bolder?



wtf is a lycanmutt? A werewolf with questionable pedigree?

Also, I don't know. Did you go back in and edit anything?

__________________
"'Peace on Earth,' was said. We sing it, and pay a million priests to bring it. After two thousand years of mass, we've got as far as poison gas." -Thomas Hardy

"Buy the ticket, take the ride." -HST
jake1100

Avatar / Picture

Veteran
Registered:
Posts: 1,451
Reply with quote  #10 
all the kinetic energy is there, but your body isnt strong enough to absorb it, a boxer's punch isnt going to go through you so it will knock you down, just like the stock of a shotgun stock wont go through your shoulder, but if that boxer had a rapier(sword with a long thin blade) and thrusted it in your gut with the same force of the punch, the force alone wouldnt knock you down, but the pain would.

dont know if that makes sense but its the best i can explain it

__________________
"Legal" and "illegal" are fuzzy gray areas for me.

I go with "moral" and "immoral" instead. Those are usually pretty clear-cut.

-Z
Unholyevil

Avatar / Picture

Loyal RCS follower
Registered:
Posts: 1,881
Reply with quote  #11 
Jake hit it pretty good with that.  A boxer's fist has no penetration, it causes blunt force.  It is not that the person receiving the bullet doesn't react, it is that the human body absorbs the impact.  When you have a high velocity, relatively lightweight projectile (a bullet) hitting a large surface area (Human skin can be considered one large surface area as it is all one piece) you are not going to transfer all 1000 Joules the bullet has.  The human body will absorb as much of the kinetic energy as it can, whatever energy is no needed is still in use by the bullet to travel forward.  Having a lot of penetration reduces overall energy TRANSFERRED, as you are hitting with a very small point.  I hope I was able to make sense of that, it all makes sense in my head but transferring it to words escapes me.

A tin can does not have the same properties as a human body.  It is far lighter, less resistant, etc. so comparing the reaction a tin can has to that of a person I believe is irrelevant.  The bullet will only transfer as much energy as needed to penetrate whatever is in front of it.  

Z, I see your point with the falling backwards thing, yes I do agree that because the bullet is traveling in that direction, the body will fall that way.  If the body was shot in the ribs from the side, I would expect the body to fall to the side as well.

__________________
Z

Avatar / Picture

Ah'm yer huckleberry
Registered:
Posts: 4,599
Reply with quote  #12 
Quote:
Originally Posted by jake1100
all the kinetic energy is there, but your body isnt strong enough to absorb it, a boxer's punch isnt going to go through you so it will knock you down,


Right, agreed, so why wouldn't a bullet that doesn't pass through you do the same thing as a boxer's punch that doesn't go through you?

Quote:
just like the stock of a shotgun stock wont go through your shoulder, but if that boxer had a rapier(sword with a long thin blade) and thrusted it in your gut with the same force of the punch, the force alone wouldnt knock you down, but the pain would.


Good example, but it's just like a bullet passing through the target. Remember, a bullet passing through will not impart all of its kinetic energy. A bullet lodging would. So modify the above example to say that the rapier catches on your sternum and refuses to enter further into the body. Wouldn't that push you back?

If it entered and went through and out your back, like you described it, I'd agree--you'd fall, but not because of the force of the thrust.  But what if it didn't go through? What if it stuck?

__________________
"'Peace on Earth,' was said. We sing it, and pay a million priests to bring it. After two thousand years of mass, we've got as far as poison gas." -Thomas Hardy

"Buy the ticket, take the ride." -HST
Z

Avatar / Picture

Ah'm yer huckleberry
Registered:
Posts: 4,599
Reply with quote  #13 
Quote:
Originally Posted by Unholyevil


Z, I see your point with the falling backwards thing, yes I do agree that because the bullet is traveling in that direction, the body will fall that way.  If the body was shot in the ribs from the side, I would expect the body to fall to the side as well.


So we're agreed, then? A round that lodges does in fact impart enough energy to affect the fall of a body?

__________________
"'Peace on Earth,' was said. We sing it, and pay a million priests to bring it. After two thousand years of mass, we've got as far as poison gas." -Thomas Hardy

"Buy the ticket, take the ride." -HST
Unholyevil

Avatar / Picture

Loyal RCS follower
Registered:
Posts: 1,881
Reply with quote  #14 
I agree to a certain point, yes.  It is all dependent on the bullet.  A small bullet like a 9mm or something of the like I don't believe would cause the body to fall in a specific way.  I say this because *sometimes* death is not instant and the body is still able to regain it's balance after the impact.  I also don't believe a bullet has to lodge itself in the body.  I do believe that a bullet that has transferred enough energy to penetrate through an entire human (exiting out the back of the body) will still cause the body to fall in a certain direction, in this case backwards, if death is instant.
__________________
ZombieHobbit

Avatar / Picture

Veteran
Registered:
Posts: 479
Reply with quote  #15 

From the stories I have read or heard from people who have been shot, most of them never even knew they had been shot until they saw the entry wound.  Almost all of them remember feeling like someone had punched them with all their strength.  Usually they are in situations where they are running on adrenalin, which is a big factor in them not noticing they had been shot. 

As for the kinetic energy.  The human body is solid and dense, filled with fluids and spongy matter.  If you have watched Mythbusters then you probably have seen them shoot at ballistic gel.  From the point of impact you see a 'ripple' effect which could be the kinetic energy of the bullet dispersing around the AOI.  A large enough slug may force them back a step, but not like it would if you shot something hard and solid, like a robot.  Which direction a person falls would depend on their balance + center of gravity.  So if they where taking a step, they may fall forward.  But if standing still they would probably fall backward.

This is what I believe, anyways.  But don't quote me on that. 

__________________
(In my defense, I had Chinese for lunch, and now I feel sluggish and content. And they barely screamed when I put them in the wok, which was a pleasant change of pace.) - Z
Unholyevil

Avatar / Picture

Loyal RCS follower
Registered:
Posts: 1,881
Reply with quote  #16 
If the bullet does lodge itself in the bone, then I would say "no the body will not fall back (unless death is instant)."  Back to the 9mm example, someone may get shot in the torso with one, and not die instantly, but they fall on their back?  They may stagger backwards a step, or not, depends on the persona nd what the bullet hi.
__________________
jake1100

Avatar / Picture

Veteran
Registered:
Posts: 1,451
Reply with quote  #17 
a bullet lodging wouldnt either, because your body absorbs it, imagine the amount of force it would take to push a full grown man's body back and onto the floor/wall/off a cliff, and then put it on say, a bullet 9mm-12 guage going atleast 800 fps, it would rip through you. So the amount of force needed to knock you down, but stay in the body is impossible to do. It would use its kinetic energy and pass straight  through you.

so basically the force needed to knock you down being put in a bullet would still tear through you.

But i have been shot by a 12 guage bean bag, and it did knock me down. But it was blunt, If the bean bag had been replaced with buck shot or whatever it would have gone in, not deep though because bean bag rounds run on low powder.

__________________
"Legal" and "illegal" are fuzzy gray areas for me.

I go with "moral" and "immoral" instead. Those are usually pretty clear-cut.

-Z
Unholyevil

Avatar / Picture

Loyal RCS follower
Registered:
Posts: 1,881
Reply with quote  #18 

Quote:
 So the amount of force needed to knock you down, but stay in the body is impossible to do.

Eh, not sure I really agree with that.  Balance is another key issue here as is human reaction.  If a bullet goes through your neck and embeds itself into the spine, and death is not instant, you are not going to be standing after the impact.  Standing normally we are slightly top heavy, and applying force to the right area can produce results.  If you have every shoved someone in the shoulders, and they take a step back, you see my point.  A shove surely does not induce over 1000J of force, yet it still has the ability to knock you off balance, a bullet hitting something hard and stopping instantly inside of you would produce a similar result, only the result would be more severe than a shove.


__________________
jake1100

Avatar / Picture

Veteran
Registered:
Posts: 1,451
Reply with quote  #19 

i dont know, for it to be slow enough not to be deflected by the spine or just blow through it wouldnt be strong enough to knock back harder then a shove. But this is all speculation


__________________
"Legal" and "illegal" are fuzzy gray areas for me.

I go with "moral" and "immoral" instead. Those are usually pretty clear-cut.

-Z
Unholyevil

Avatar / Picture

Loyal RCS follower
Registered:
Posts: 1,881
Reply with quote  #20 
After a bullet has entered the body and used up, at least, some of it's kinetic energy will be spent, and the bullet will be deformed (small caliber bullets, like a 9mm).  I can't see a 9mm round over penetrating the target, and penetrating the spine.  I can see a 9mm bullet passing through the body without hitting the spine, but once it hits the spine I have a feeling the bullet will be stopped.  Reaction to this would be to at least keel over, and fall, most likely backwards.  Keeling over puts more weight behind your center of gravity, and after a severe trauma incident like described above, your balance is not coming back.  This too, is all speculation based on the force required to break the spine, muzzle energy of the bullet, deformation of bullet after initial entry, target standing straight up, etc.
__________________
Nurgle

Avatar / Picture

Veteran
Registered:
Posts: 1,120
Reply with quote  #21 

What about that 20mm cannon from the latest rambo that should have some knockback?


__________________
Nyghtreaver

Believes in nothing
Registered:
Posts: 1,499
Reply with quote  #22 

ok, first i am assuming we are talking about zombies, and basing everything i say on bullet impact on a zombie.

Balance is a key issue. you guys covered the knocking backwards part. but zombies arew uncordinated so i do beleive they would fall, probably more in line with tripping over their feet.

2nd note, and this is key to balance, a perfect center mass hit would have minimal effect on balance, and would purely be force, penetration etc. however, a hit to the shoulder that lodges would give a spinning effect. Basically the farther from the center of gravity the greater the noticable effect.  Zombies are uncordinated, therefore a 25 degree shift in direction would make them fall.

think of it like this. stand on stilts. have a friend use a tennis ball launcher that tennis players use. take a hit to direct center mass, you will probably stay up. take a hit to the upper arm, the impact may be enough to make you lose your balance

PS: if anyone actually does this please!!!!!!1 video it


__________________
I used to believe in nothing, now I beleive in Darrell
DocT

Avatar / Picture

Zombie Slayer
Registered:
Posts: 644
Reply with quote  #23 
The Mythbusters got it right even though many here on the board are not quite understanding why.

The two Physics principles involved are conservation of energy AND momentum.  In the calculations, one quickly sees that its the significantly larger MASS of the body compared to the bullet which is the key to the answer. Unless the rifle or pistol round is going at a velocity much larger than is currently possible with today's propellants, the much smaller mass of the bullet doesn't transfer that much energy and momentum to the body.  The body's final velocity is therefore negligible. That is not to say that the round does not cause massive damage to the body, its just the body's final velocity is so very very small, the body only slumps because of the effect of the damage..

In get a comparison, just think about how much work (i.e. energy consumed) is needed to get a human body up to a running speed. That's why the human race domesticated horses, let them do the work for us...

Finally, Total Energy is still conserved in that the original Potential and Kinetic Energy of the round is converted into final Potential Energy (calculated by height above ground when round stops in body) and Heat Energy (distributed by friction with tearing tissue by the penetrating round) as well as Heat of Vaporization as liquids in tissue evaporate (not an excessive amount of energy loss, but still measurable.).

Final note:  If rail gun technology is ever fully developed and miniaturized, a tiny amount of mass, say a bb size object, traveling just under escape velocity, will literally explode targets due to the energy transfer.


__________________
"When a guy walks away from three 5.56 rounds to the face, then I will give up my AR15."
jake1100

Avatar / Picture

Veteran
Registered:
Posts: 1,451
Reply with quote  #24 
yes explode, but the actual bb size object wont send it flying. And nyghtreaver, we're talking about living people, Not zombies.

__________________
"Legal" and "illegal" are fuzzy gray areas for me.

I go with "moral" and "immoral" instead. Those are usually pretty clear-cut.

-Z
John_Brian_K

Avatar / Picture

Post-Accumulating Whore
Registered:
Posts: 2,750
Reply with quote  #25 

Quote:
Originally Posted by Z


Your thoughts?

Well this is an interesting discussion.  Right off the top of my head I would think that unless a bullet hits bone it will not spin or knock a Z over.  It is all dependent on the type of bullet and the decompisition of the body the Z is in.

If the Z has been blasted multiple times before in the chest cavity and you go to shoot him in the chest (for some dumb reason) the bullet would most likely fly right through unless it hits bone of course.

I used to frequent Rec.Gambling.Poker ALL the time.  I was a regular for a couple years and something alot of the people over there used to say when we talked poker was 'It Depends' and it seems to qualify here.

__________________
====
JBK
Dec 09, 2009 at 10:18 AM
========================
"Something my granddad used to tell us. You know Macumba? Voodoo. My granddad was a priest in Trinidad. He used to tell us, "When there's no more room in hell, the dead will walk the earth."
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.