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View Full Version : If we equate Kinetic Energy to Physical Damage, can we kill all the catgirls at once?



Chess435
2011-05-20, 07:18 PM
Warning: Math Ahead
You have been warned.

Anyway, playground, I have sort of a challenge for you. Assume for the purposes of this thread that D&D physics = Real Life Physics.

The Challenge:
It all started with me wondering this: What would happen if we took an ubercharger, straight out of TO, and had it attack, say Mt. Everest? In order to contemplate such a thing, I figured that we'd have to figure out how much Kinetic Energy it would take, on average, to equal 1 point of damage in D&D. At this point, we could multiply this value by the average damage output of our ubercharger to find how much energy he uses in a single round. Finally, we can compare this amount of energy to other things, such as a supernova, to see if a string of attacks from one of these characters is enough to destroy all life, including catgirls, in the galaxy.

Steps Recommended:
1. With real-world examples, try to come up with a rough approximation of how much energy it takes to deal 1 point to something.
2. Scour the internets for the single-round non-infinite damage record.
3. Do the math, and compare results with other stuff, in order to come up with casualty estimate.
4. ??????
5. Profit!

Let me know if I made any bad assumptions or mistakes!

So, playground, are you up to the challenge?

Divide by Zero
2011-05-20, 07:21 PM
2. Scour the internets for the single-round non-infinite damage record.

Hulking Hurler can get around (10^271)d6 damage, which is many orders of magnitude greater than the number of particles in the universe. I think it can break everything.

And there's some build I can't quite remember that involved (some 5ish-digit number)^^(some other 5ish-digit number), but I can't remember what it was or if that was its damage output.

Madcrafter
2011-05-20, 07:48 PM
As has been discussed elsewhere, starting to think of hit points in terms of real world equivalents makes things... weird. The amount of energy required for a point of damage would vary wildly depending on how and where it is applied, as well as the interval of that application and what it is applied to. Estimations of the energy of any build would vary wildly, and therefore your query is difficult to answer specifically.

mootoall
2011-05-20, 07:51 PM
Hulking Hurler can get something like (10^83)d6 damage, which is many orders of magnitude greater than the number of particles in the universe.

I ... I want to sig this ... May I?

Divide by Zero
2011-05-20, 07:57 PM
Never mind, I was off by quite a bit. Most updated version I can find (here (http://community.wizards.com/go/thread/view/75882/19873078/Hulking_Hurler_build&post_num=963#338560114)) says 10^271. Gonna edit my first post with that; feel free to sig it if you want.

Madcrafter
2011-05-20, 08:02 PM
10^83 is right within the estimated range for number of atoms in the known universe, so you were sort of spot on in a sense.

Jack_Simth
2011-05-20, 08:20 PM
As part of item 1, look to the lowly Torch (http://www.d20srd.org/srd/equipment/goodsAndServices.htm#torch):

Torch

A torch burns for 1 hour, clearly illuminating a 20-foot radius and providing shadowy illumination out to a 40-foot radius. If a torch is used in combat, treat it as a one-handed improvised weapon that deals bludgeoning damage equal to that of a gauntlet of its size, plus 1 point of fire damage. (Emphasis added)

There. The heat output of a torch does one point of damage. We've got a pesky problem of "how long is the contact on a hit", but we've got something of a baseline.

Alternately, Falling Objects (http://www.d20srd.org/srd/environment.htm#fallingObjects) are likely not consistent, but can get you there. Pick an object and a distance for a baseline. You'll probably get different numbers, but in a vacuum, impact energy on earth is just mgh = mass * gravity of earth * height.

Lateral
2011-05-20, 08:22 PM
Well, we can try taking how much energy would be required for a Hulking Hurler to deal 1 point of damage by hurling something- that is, how much energy you get from throwing however much weight is needed to deal 1 damage with a Hulking Hurler. (I don't have the Miniatures Handbook, so I don't really know the rules for it.)

Chess435
2011-05-20, 09:47 PM
Let's see: A hulking hurler's rocks weigh 50 pounds (22.67 kg), and deal 2d8 damage, which averages to 9. Unfortunately, we don't know how fast the rocks travel. Let's assume they fly through the air at 100 feet per second, which can get the rock to it's maximum range in 2.5 seconds. This converts to 30.48 m/s, allowing us to solve for the KE.

KE = .5*M*V^2

KE = .5*22.67*(30.48)^2

KE = 10,530 J of energy, about the energy realeased by the metabolism of 2/3 of a gram of sugar. :smalltongue:

Dividing that by 9, we end up with a rough approximation of 1170 J per point of damage.

Now, the fun part..........

Let's assume the 3.5 x 10^271 damage record.

Multiplying this by 1170, we end up with 4.095 x 10^274 J of energy.

To put this into perspective, the total estimated mass energy of the universe is 4 x 10^69 J.

So I guess the universe explodes if a TO monstrosity attack in it. 10^205 times over. (This is ignoring conservation of mass and energy, by the way.)


Edit: I guess all the cat girls are dead forever now. Along with everything else, for that matter. :smallbiggrin:

Lateral
2011-05-20, 09:54 PM
We must test this theory, in the name of MAD SCIENCE. :smalltongue:

Chess435
2011-05-20, 09:58 PM
We must test this theory, in the name of MAD SCIENCE. :smalltongue:

I guess we found what tomorrow's Apocalypse will consist of. Right before we all die, the TO'ers of this world shall bow before this monstrosity's stacked templates! :smallbiggrin:

Jack_Simth
2011-05-20, 10:14 PM
Let's see: A hulking hurler's rocks weigh 50 pounds (22.67 kg), and deal 2d8 damage, which averages to 9. Unfortunately, we don't know how fast the rocks travel. Let's assume they fly through the air at 100 feet per second, which can get the rock to it's maximum range in 2.5 seconds. This converts to 30.48 m/s, allowing us to solve for the KE.

KE = .5*M*V^2

KE = .5*22.67*(30.48)^2

KE = 10,530 J of energy, about the energy realeased by the metabolism of 2/3 of a gram of sugar. :smalltongue:

Dividing that by 9, we end up with a rough approximation of 1170 J per point of damage.

Now, the fun part..........

Let's assume the 3.5 x 10^271 damage record.

Multiplying this by 1170, we end up with 4.095 x 10^274 J of energy.

To put this into perspective, the total estimated mass energy of the universe is 4 x 10^69 J.

So I guess the universe explodes if a TO monstrosity attack in it. 10^205 times over. (This is ignoring conservation of mass and energy, by the way.)


Edit: I guess all the cat girls are dead forever now. Along with everything else, for that matter. :smallbiggrin:

So he can throw the mountain, but he burns the entire mass of the universe 10^205 times over to do it?

You have to wonder about his diet.... and his metabolism, if he can actually do that.

Chess435
2011-05-20, 10:21 PM
Yeah, KE = .5MV^2 and E=MC^2 interact in a very odd fashion. :smallsmile:

Jack_Simth
2011-05-20, 10:45 PM
Yeah, KE = .5MV^2 and E=MC^2 interact in a very odd fashion. :smallsmile:
Hey now - if you're bringing e=mc^2 into this, then you have to use the relativistic version: e = (mc^2)/(sqrt(1-((v^2)/(c^2))), and ke=(mc^2)/(sqrt(1-((v^2)/(c^2))) - mc^2

faceroll
2011-05-20, 11:53 PM
Never mind, I was off by quite a bit. Most updated version I can find (here (http://community.wizards.com/go/thread/view/75882/19873078/Hulking_Hurler_build&post_num=963#338560114)) says 10^271. Gonna edit my first post with that; feel free to sig it if you want.

Baby Shump, the creature used as the hulking hurler, has some issues. One of which being he has an ECL of like 300 something.

BobVosh
2011-05-21, 12:47 AM
Isn't dynamite a standard for determining force? I will never claim to be reasonably educated in such fields, but dynamite is stated. Should be fairly easy with...math stuff...to figure it out from there.

Divide by Zero
2011-05-21, 01:38 AM
Edit: I guess all the cat girls are dead forever now. Along with everything else, for that matter. :smallbiggrin:
Just a bit. This is almost as bad as that time I saw someone suggest casting reverse gravity on a black hole.

Baby Shump, the creature used as the hulking hurler, has some issues. One of which being he has an ECL of like 300 something.

You're forgetting that Tauric is horribly broken.

Swordguy
2011-05-21, 01:47 AM
Isn't dynamite a standard for determining force? I will never claim to be reasonably educated in such fields, but dynamite is stated. Should be fairly easy with...math stuff...to figure it out from there.

Yes, it is. 1kg of TNT releases a maximum of 4.7MJ of energy. 1 lb of TNT can do a maximum of 18hp damage. Standardize your units of measurement, and figure out how many grams of TNT=1hp damage. Then start converting your damage over into larger units - like kilotons (1 million grams in a kiloton; how many hp damage is that?).

This is the same line of thought that led me to create the anti-osmium bomb several years ago.

BobVosh
2011-05-21, 02:27 AM
Yes, it is. 1kg of TNT releases a maximum of 4.7MJ of energy. 1 lb of TNT can do a maximum of 18hp damage. Standardize your units of measurement, and figure out how many grams of TNT=1hp damage. Then start converting your damage over into larger units - like kilotons (1 million grams in a kiloton; how many hp damage is that?).

This is the same line of thought that led me to create the anti-osmium bomb several years ago.

And your anti-osmium bomb is what made me remember TNT is in a book. Circuitous isn't it?

ffone
2011-05-21, 02:55 PM
Why does HP of damage have to be linear in / proportionate to any physical quantity? Maybe it's some other monotone function.

Then of course there are damage types that probably don't involve lots of energy or momentum or mass, like sneak attack damage, which small creatures can be good at dealing lots of.

A 20th-level rogue with Craven flips a coin then sneak attacks one of two targets - a human, or a vampire disguised like the human. The rogue probably has the same (probability distribution of) energy/momentum/whatever involved in the attack, yet the damage dealt is very different. (The attack vs the vampire is not a 'sneak attack' mechanically, but the rogue doesn't know that until after making it.)

Come to think of it, the falling damage / hulking hurler damage probably exposes an inconsistency in how DnD attempts to map physical quantities to HP damage, if it does at all.

Regular damage is linear in Strength, yet carrying capacity is exponential - so far that's OK, it just suggests HP damage is logarithmic in the relevant physical quantity (if there's any relationship at all) - but then falling object damage is linear in weight, hence the exponential damage of a hulking hurler, suggesting a linear rather than logarithmic relationship.

Urpriest
2011-05-22, 03:12 PM
For blowing up a mountain or the like, it seems more prudent to find the mountain's HP from its mass/shape/etc. than to find the energy it takes to destroy it.

Moriato
2011-05-22, 03:18 PM
I don't think you can directly equate HP damage to kinetic energy. It really depends a lot on how that energy is applied. For instance if you took the amount of energy it took a rapier to do 1HP worth of damage, and then tried to use that same amount of energy to do damage with a greataxe, it probably wouldn't even be enough to lift the greataxe, let alone damage something with it.

Spiryt
2011-05-22, 03:32 PM
I don't think you can directly equate HP damage to kinetic energy. It really depends a lot on how that energy is applied. For instance if you took the amount of energy it took a rapier to do 1HP worth of damage, and then tried to use that same amount of energy to do damage with a greataxe, it probably wouldn't even be enough to lift the greataxe, let alone damage something with it.

You can't obviously.:smallwink:

40 J KE football is going to whack you pretty good, so you can feel the pain for 20 seconds, or so.

40 J ~50 gr arrow with any sort of iron or antler tip can can skewer you right trough.

Lord.Sorasen
2011-05-22, 05:12 PM
Let's see: A hulking hurler's rocks weigh 50 pounds (22.67 kg), and deal 2d8 damage, which averages to 9. Unfortunately, we don't know how fast the rocks travel. Let's assume they fly through the air at 100 feet per second, which can get the rock to it's maximum range in 2.5 seconds.

If we assume no air resistance we can figure out the speed for sure. If for instance we say it was thrown at the ideal angle for distance (45 degrees) at a height for a large creature of about 10 feet, then we can get the equation. It took me forever because I haven't taken physics in 2 years (or any math beyond algebra) and I didn't want to access books, but it's ultimately -32.15(time)^2=-60, giving us a time of square root of (60/32.15). And then (horizontal speed)(time)=50, and then 2(horizontal speed)^2=(Speed)^2.

I don't want to do the math outright but that's about the speed for your average giant.

Eldan
2011-05-22, 05:16 PM
Falling deals 1d6 damage per 10 feet. Surely we can calculate something from that?

Techsmart
2011-05-22, 05:39 PM
Hey now - if you're bringing e=mc^2 into this, then you have to use the relativistic version: e = (mc^2)/(sqrt(1-((v^2)/(c^2))), and ke=(mc^2)/(sqrt(1-((v^2)/(c^2))) - mc^2

Thank you. Now I feel better about getting that physics degree :P

The concept of damage, as stated, doesn't work at all in translating to real life. Yes, a burning torch deals one damage to you. So does a cat scratching a commoner to death. If you look through all the damage quantities, there are tons of different things that can cause the same ammount of damage, with radically different energy requirements.

Chess435
2011-05-22, 08:03 PM
Darn. I was hoping to bring new meaning to the words "Rocks Fall, Everyone Dies" :smallbiggrin:

Then again, as long as I wasn't off by over 200 orders of magnitude, the end result should be fairly similar. And I don't think I've been that far off before. :smallwink:

Jack_Simth
2011-05-22, 09:01 PM
Thank you. Now I feel better about getting that physics degree :PAh, you mean you're not going to tell me exactly which parenthesis I'm missing?

enderlord99
2011-07-16, 10:56 AM
Ah, you mean you're not going to tell me exactly which parenthesis I'm missing?

This one: ")"

NNescio
2011-07-16, 12:31 PM
Hulking Hurler can get around (10^271)d6 damage, which is many orders of magnitude greater than the number of particles in the universe. I think it can break everything.

And there's some build I can't quite remember that involved (some 5ish-digit number)^^(some other 5ish-digit number), but I can't remember what it was or if that was its damage output.

One of LoP's nasty tricks (http://community.wizards.com/go/thread/view/75882/19868594/World_Record_Damage:_Multiple_dirty_tricks_for_ins ane_synergy!&post_num=58#338279018) managed to pull off (2.5*1036530)↑↑73600 damage. It deals... a lot of damage to the point that scientific notation can no longer express it adequately. (The double ↑ sign is from Knuth's up-arrow notation (http://en.wikipedia.org/wiki/Knuth%27s_up-arrow_notation))

For comparison:
5↑↑1 = 5
5↑↑2 ≈ 3.12*103
5↑↑3 ≈ 2.98*1017
5↑↑4 ≈ 2.35*1087

This is probably where your 5-ish number come from.

Yeah... that's a scarily huge number.

Divide by Zero
2011-07-16, 12:55 PM
One of LoP's nasty tricks (http://community.wizards.com/go/thread/view/75882/19868594/World_Record_Damage:_Multiple_dirty_tricks_for_ins ane_synergy!&post_num=58#338279018) managed to pull off (2.5*1036530)↑↑73600 damage. It deals... a lot of damage to the point that scientific notation can no longer express it adequately. (The double ↑ sign is from Knuth's up-arrow notation (http://en.wikipedia.org/wiki/Knuth%27s_up-arrow_notation))

For comparison:
5↑↑1 = 5
5↑↑2 ≈ 3.12*103
5↑↑3 ≈ 2.98*1017
5↑↑4 ≈ 2.35*1087

This is probably where your 5-ish number come from.

Yeah... that's a scarily huge number.

Yeah, that was the one I was thinking of.

randomhero00
2011-07-16, 02:23 PM
The thing is the mountain doesn't exactly have its own hps, it shares it with the earth. Whatever thrown at it strong enough to do that kind of damage would likely disintegrate on the way there and just make a crater in the mountain.

Also, wtf is a catgirl?

Jack_Simth
2011-07-16, 02:58 PM
The thing is the mountain doesn't exactly have its own hps, it shares it with the earth. Whatever thrown at it strong enough to do that kind of damage would likely disintegrate on the way there and just make a crater in the mountain.

Actually, particularly large objects have HP in 10x10x5 foot sections, based on their material.


Also, wtf is a catgirl?
That one you'll want to Google.

BobVosh
2011-07-16, 03:02 PM
Also, wtf is a catgirl?

Catgirl (http://tvtropes.org/pmwiki/pmwiki.php/Main/CatGirl)

Science kills a catgirl.
10 letters

Thorin!
2017-02-24, 08:11 AM
Baby Shump, the creature used as the hulking hurler, has some issues. One of which being he has an ECL of like 300 something.


What is a baby Shump??? and an ECL of 300???

Lord Haart
2017-02-24, 08:36 AM
If we equate Kinetic Energy to Physical Damage, can we kill all the catgirls at once?
Well, if we do…
1. It isn't possible to take less than 1 point of damage unless it's reduced by DR, resistance, regeneration, or any other quality/effect that reduces it after it's already calculated.
2. We're surrounded by air, which consists of moleculae, which all have kinetic energy which they constantly impart into us on impact.
3. Therefore, as soon as we equate thusly, every corporeal catgirl that is surrounded by a gas or a liquid (or a solid body, i guess) and doesn't posess DR (or some other sufficient quality/effect) starts taking a bazillion of impacts each round, which deal (at least) 1 point of damage each. Some of them happen on the inside of her body (the surface of her lungs) which probably mitigates some additional forms of protection.

So yes, we do kill all of them at once.


Unless you rule that moleculae are blunt, soft and inefficient at dealing damage. Then they deal nonlethal damage and the catgirls merely get battered into one hell of a coma.

Allanimal
2017-02-24, 09:48 AM
The catgirls may die, but the thread necromancers bring them back...