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Message no. 1
From: Mark Kalvin <Sahtori@***.COM>
Subject: Re: Melting Bullets, more about them...
Date: Tue, 21 Mar 1995 02:37:44 -0500
In response to a posting by Gurth:

> Well, he couldn't target a specific bullet because he can't see it.
> Technically it's in his field of vision, but ...You could use a anchored
spells --
> Detect Bullets, which then switches on a Turn Bullet To Other Form Of
Energy > spell.

Damion Milliken University of Wollongong adm82@***.edu.au, wrote the
following:



> Well, I'd be thinking that the "Turn Bullet To Other Form Of Energy" spell
> would be more or less a Bullet Barrier spell. It requires an input of
> magical energy from the caster, and it stops bullets getting to the target.
> While a normal Bullet Barrier spell uses the spells energy to provide an
> inpenetrable barrier to bullets (whether you rule it forms air molecules
> into a hard wall, or manifests astral energy to the physical in the shape
of
> a wall or whatever), a "Turn Bullet To Other Form Of Energy" spell uses the
> same spell energy, but in a different manner. End result? Same thing
> happens the bullet is stopped short of hitting its target by the power of
the
> spell. Sure the special effects are different, but it has essentially the
> same end result. I don't think it would be overbalancing or munchkinous at
> all. Just a little more stylish than a regular Bullet Barrier (and, hey,
> it's style that counts after all isn't it? :-)).

Actually, gents, the spell in question is one that converts the bullets
*momentum* into another form of energy (converting the actual bullet to
energy would result in something very like the world's largest single nuclear
detonation :-)). I came up with the spell for the short story, "The
Red-Haired German" that I posted here a few days ago. It is the patent of the
character Paolo Stevens, an elven Hermetic Adept.

The idea behind the spell is to stop bullets while creating an interesting
visual: no matter how one triggers the spell, the idea is that the energy
that carries the bullet, arrow, or what have you forwards is converted into
heat and light, causing the projectile to stop in the air and, in the case of
bullets---which travel with enormous energy---to melt. I am not sure whether
or not the actual spell is viable under the vanilla rules. In other respects,
it is completely similar to the bullet barrier spell.

The reason I posted the idea, is to get some input on what people think about
the spell's effect on game balance if any.

Thanks for your attention,

Mark Kalvin (Sahtori@***.com)
Message no. 2
From: Robert Watkins <bob@**.NTU.EDU.AU>
Subject: Re: Melting Bullets, more about them...
Date: Tue, 21 Mar 1995 17:26:40 +0930
Mark Kalvin wrote:
> The idea behind the spell is to stop bullets while creating an interesting
> visual: no matter how one triggers the spell, the idea is that the energy
> that carries the bullet, arrow, or what have you forwards is converted into
> heat and light, causing the projectile to stop in the air and, in the case of
> bullets---which travel with enormous energy---to melt. I am not sure whether
> or not the actual spell is viable under the vanilla rules. In other respects,
> it is completely similar to the bullet barrier spell.

Actually, bullets travel with sweet f.a. energy...

Remeber, the kinetic energy of an object is dependent on mass and
velocity(squared). While the velocity of the object is fairly high, the
mass is very low.

I rather doubt that if you converted the kinetic energy in the bullet's
momentum relative to you that it would melt it.

Hey... what happens if the bullet is above you when it hits the barrier? :)
I mean, the barrier stops the bullet, by converting it into molten slag.
But the molten slag is no longer a bullet, so the barrier lets it
through... Gravity causes it to fall down and hit you. :)

--
Robert Watkins bob@**.ntu.edu.au
Real Programmers never work 9 to 5. If any real programmers
are around at 9 am, it's because they were up all night.
Finger me for my geek code
Message no. 3
From: Keith Johnson <jrsnyder@********.WISC.EDU>
Subject: Re: Melting Bullets, more about them...
Date: Tue, 21 Mar 1995 08:40:47 -0600
>>Mark Kalvin wrote:
>> causing the projectile to stop in the air and, in the case of
>> bullets---which travel with enormous energy---to melt.
>
>Robert Watkins writes:
>
[snip}
>I rather doubt that if you converted the kinetic energy in the bullet's
>momentum relative to you that it would melt it.
>
Keith here again...

according to the heat transfer equations I know, if the change
happens fast enough (as if by magick) the bullets could be
vaporized. If they're small enough and if they're going fast
enough and if the change happens fast enough and if they're
made from normal materials (copper, lead, uranium. as
opposed to some kind of plastic).

My question is what happens if you put up a magical barrier
that turns the mass of the bullet into, say, thermal energy?
Can you say thermo-nuclear doom! Now what happens if that
barrier is put right behind the guys that your _partners_ are
shooting at? Any mage who needs a gun isn't spending their
karma well.

You could use micro bullets to keep from melting the city.
Figure out how many ergs of thermal you need, then do the
Einstein dance, and you know the mass of the round you need.
I think a small mass driver would do nicely.

Of course, thrying to convince an Ork to shoot over the heads
of his target instead of right at his target...

Hugs and kisses,

Keith

-Well, he does have some redeeming qualities...-
-Yes, but I don't have any problems with those!-

Jessica Snyder and Andrea Keller
Discussing Keith Johnson
Message no. 4
From: Adam Getchell <acgetche@****.UCDAVIS.EDU>
Subject: Re: Melting Bullets, more about them...
Date: Tue, 21 Mar 1995 10:29:25 -0800
On Tue, 21 Mar 1995, Robert Watkins wrote:

> Actually, bullets travel with sweet f.a. energy...

True, but this one actually surprised me:

Let's take a 1 gram mass at 1000 meters/sec. 1/2*m*v^2 gives 500
joules of energy (compare with a kick at 30 miles per hour = 44
meters/sec and 5 kilograms of mass yielding 4840 joules):

Now for lead, the specific heat is 130 Joule/kg-K. 500/130=3.8
degrees K, but a 1 gram mass will heat up to 3800 degrees! That's for a
pure lead bullet.
On the other hand, steel has a specific heat in the 450-500
range, so using 500 we get a heat change of 1000 degrees Kelvin.
However, since the melting point of steel is 1400-1600 Kelvin, there's no
problem there.
These are simplified calculations, assuming linear thermal
properties, but the results are somewhat instructive and interesting, eh?
Finally, note that you can dose someone with more kinetic energy
by kicking them or hitting them with a bat than by shooting them.

> I rather doubt that if you converted the kinetic energy in the bullet's
> momentum relative to you that it would melt it.

That's pretty much true for ball ammo, but bullets with a large
amount of lead content would be different (lead melts at 327 Celsius,
while lead alloys melt in the 182-326 Celsius range).

> Robert Watkins bob@**.ntu.edu.au

========================================================================
Adam Getchell "Invincibility is in oneself,
acgetche@****.engr.ucdavis.edu vulnerability in the opponent."
http://instruction.ucdavis.edu/html/getchell.html
Message no. 5
From: Damion Milliken <adm82@***.EDU.AU>
Subject: Re: Melting Bullets, more about them...
Date: Thu, 23 Mar 1995 20:33:32 +1000
Keith Johnson writes:

> My question is what happens if you put up a magical barrier
> that turns the mass of the bullet into, say, thermal energy?
> Can you say thermo-nuclear doom!

I suggest you read page 115 of the Grimything II, and note in particular the
reference to the "hurricane" spell on that page... :-)

--
Damion Milliken University of Wollongong E-mail: adm82@***.edu.au

(GEEK CODE 2.1) GE -d+@ H s++:-- !g p0 !au a18 w+ v(?) C++ US++>+++ P+ L !3
E? N K- W M@ !V po@ Y+ t+ 5 !j R+(++) G(+)('''') !tv(--@)
b++ D B? e+$ u@ h* f+ !r n----(--)@ !y+
Message no. 6
From: Luke Kendall <luke@********.CANON.OZ.AU>
Subject: Re: Melting Bullets, more about them...
Date: Fri, 24 Mar 1995 09:51:38 +1000
This is in the nature of a `... hey, wait a minute!'

Someone posted a comparison of the impact of a bullet and a kick,
showing that the kick delivered more energy. But assuming:

leg: 10kg, 10m/s bullet: 1g, 1000m/s

gives:
leg: 500 cal bullet: 500,000 cal

This is much more reasonable - the bullet delivers far more
energy, and can be expected to do more damage. (kinetic energy = 0.5 mv^2)

luke
Message no. 7
From: Robert Watkins <bob@**.NTU.EDU.AU>
Subject: Re: Melting Bullets, more about them...
Date: Fri, 24 Mar 1995 11:25:22 +0930
Luke Kendall wrote:
>
> This is in the nature of a `... hey, wait a minute!'
>
> Someone posted a comparison of the impact of a bullet and a kick,
> showing that the kick delivered more energy. But assuming:
>
> leg: 10kg, 10m/s bullet: 1g, 1000m/s
>
> gives:
> leg: 500 cal bullet: 500,000 cal
>
Try 0.5 x 10,000 x 100 (for leg) and 0.5 x 1 x 1,000,000 (for bullet)

Can't remember the unit (I thought it gave off Joules, not cals.), but it's
obvious to see they have the same amount of kinetic energy, for those
masses.

--
Robert Watkins bob@**.ntu.edu.au
Real Programmers never work 9 to 5. If any real programmers
are around at 9 am, it's because they were up all night.
Finger me for my geek code
Message no. 8
From: Todd James Gillespie <toddg@****.ACS.UNT.EDU>
Subject: Re: Melting Bullets, more about them...
Date: Thu, 23 Mar 1995 21:41:42 -0600
On Fri, 24 Mar 1995, Robert Watkins wrote:

> Luke Kendall wrote:
> >
> > This is in the nature of a `... hey, wait a minute!'

So is this.

> > Someone posted a comparison of the impact of a bullet and a kick,
> > showing that the kick delivered more energy. But assuming:
> >
> > leg: 10kg, 10m/s bullet: 1g, 1000m/s
> >
> > gives:
> > leg: 500 cal bullet: 500,000 cal
> >
> Try 0.5 x 10,000 x 100 (for leg) and 0.5 x 1 x 1,000,000 (for bullet)

Scrap the calculations for KE delivered. You forgot the fact that a leg
is NOT flying directly at a target with it's entire mass, and little
rotation (if it is, check your pain editor and damage compensators to see
if that was YOUR leg that just flew across the room). In reality, you
have to calculate torque of the leg-foot system. (For simplicity, never
mind the hand-elbow-neck-shoulders-torso-hip-leg-knee-leg-foot system.)
Seeing as I just got out of class and my mind is in shock, I don't feel
like calculating this right now. I also don't feel like finding the mass
of a foot. (I also don't have access to cadavers.)
Besides, the actual KE delivered is NOT the most important factor.
Message no. 9
From: Adam Getchell <acgetche@****.UCDAVIS.EDU>
Subject: Re: Melting Bullets, more about them...
Date: Tue, 28 Mar 1995 13:12:01 -0800
On Fri, 24 Mar 1995, Robert Watkins wrote:

> Can't remember the unit (I thought it gave off Joules, not cals.), but it's
> obvious to see they have the same amount of kinetic energy, for those
> masses.

That's correct, it would be 500 _Joules_ in each case.
However, my original numbers were leg at _30_ meters per second
which for us Americans is 44 miles per hour, roughly, quite do-able for
kicking velocity (I have read of kicks clocked at 75 miles per hour).
This gives the kick nine times the energy of the bullet.
As someone pointed out dealing with biomechanics, it is not a 10
kilogram mass. Howsomever, one can correctly calculate the kinetic
energy delivered in a round house kick by using R.K.E. = .5 I*w^2, where
I equals moment of inertia of the leg and w = angular velocity. Due to
my engineering dynamics class, I actually have quite good numbers of I
for the foot/ankle/calf/knee/thigh system but I didn't really want to
burden people with these calculations.
They really come out fairly similiar, and the basic point remains
that one can deliver more raw kinetic energy by using melee weapons and
techniques than with bullets.
As far as calculating the "damage", that's another can of worms
entirely.

> Robert Watkins bob@**.ntu.edu.au

========================================================================
Adam Getchell "Invincibility is in oneself,
acgetche@****.engr.ucdavis.edu vulnerability in the opponent."
http://instruction.ucdavis.edu/html/getchell.html

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