Weight vs Mass

[Veknironth]

Well, this is going to be one of my most pedantic questions yet. If a weightlessness enchantment is placed on armor, does that effect it's mass? The power description says it weighs no more than an ounce but mentions nothing about the mass. The wizard spell of Weightlessness mentions the mass being lowered, but not the enchantment. I ask for considerations of density and floating.

-Vek
"You could drown in weightless armor if the density is the same as regular armor."

[The Beast]

Stop overthinking it.

[Soldier of Od]

Quote from spell description: "the amount of weight the person can lift and carry are also reduced by 75%, because the weightless character doesn't have the mass to inflict serious damage or carry heavy items."

So it mentions mass too. Hope that helps.

[Kraynic]

Personally, I treat it as only reducing weight while worn. Otherwise, my players would hate me for having their chainmail (or whatever) blow away in a strong wind then they took it off. If it doesn't have mass, would it have reduced performance as armor, since it would have reduced impact on how kinetic damage would be transferred from a weapon through the armor to the body of the wearer? (Not that I have any interest in diving down a rabbit hole like that in game.)

[Hotrod]

Personally, I treat it as only reducing weight while worn. Otherwise, my players would hate me for having their chainmail (or whatever) blow away in a strong wind then they took it off. If it doesn't have mass, would it have reduced performance as armor, since it would have reduced impact on how kinetic damage would be transferred from a weapon through the armor to the body of the wearer? (Not that I have any interest in diving down a rabbit hole like that in game.)

Protection-wise, I don't see any benefit to body armor having a lot of mass. What matters are properties like tensile strength, hardness, resistance to deformation, and ability to distribute the force and shock of an impact over a wide area.

[Kraynic]

Maybe, but it just seems to me (maybe wrongly) that reducing the mass of something would reduce all/most of those characteristics. After all, these are presented as enchantments that are added after the fact, so you have a normal breastplate (or whatever) that was made the thickness needed for the tensile strength, hardness, etc. to function. Then someone comes along and removes most of it's mass. Wouldn't a reduction of mass (molecular structure) reduce all those things? Or maybe it wouldn't, since it is magic doing so.

[Hotrod]

Maybe, but it just seems to me (maybe wrongly) that reducing the mass of something would reduce all/most of those characteristics. After all, these are presented as enchantments that are added after the fact, so you have a normal breastplate (or whatever) that was made the thickness needed for the tensile strength, hardness, etc. to function. Then someone comes along and removes most of it's mass. Wouldn't a reduction of mass (molecular structure) reduce all those things? Or maybe it wouldn't, since it is magic doing so.

Those properties are driven by chemical bonds, lattice patterns, and microcrystalline structures in the metals, not by the mass of those metals. You can have very strong materials that don't weigh much. Aluminum and diamond are good examples of this.

In any case, it's magic, so I usually turn the materials science part of my brain off. This is a strange topic.

[Axelmania]

Protection-wise, I don't see any benefit to body armor having a lot of mass. What matters are properties like tensile strength, hardness, resistance to deformation, and ability to distribute the force and shock of an impact over a wide area.

I guess moving at equivalent speeds, a higher-mass object would carry more force to do more damage... but then if it's lower mass there's less inertia to overcome to accelerate it, so you can get it moving up to a higher speed...

Nonetheless, punching while holding a roll of quarters is a thing... maybe because people have trouble moving at high speeds anyway so if they can't move faster, they move more mass at the same speed?

I'm beginning to wonder though... if you reduced a 10lb helmet to 1lb, would it fall slower? Feathers only fall the same speed in a vacuum... if an object has less mass then wouldn't air resistance slow it down better if it had the same profile?

[kiralon]

if mass and inertia were a thing, fleet feet would do more damage as well as let you move faster (not to mention the strength and hand eye co-ordination required to say swing a goupillion flail twice as fast effectively)

[Hotrod]

Protection-wise, I don't see any benefit to body armor having a lot of mass. What matters are properties like tensile strength, hardness, resistance to deformation, and ability to distribute the force and shock of an impact over a wide area.

I guess moving at equivalent speeds, a higher-mass object would carry more force to do more damage... but then if it's lower mass there's less inertia to overcome to accelerate it, so you can get it moving up to a higher speed...

Nonetheless, punching while holding a roll of quarters is a thing... maybe because people have trouble moving at high speeds anyway so if they can't move faster, they move more mass at the same speed?

I'm beginning to wonder though... if you reduced a 10lb helmet to 1lb, would it fall slower? Feathers only fall the same speed in a vacuum... if an object has less mass then wouldn't air resistance slow it down better if it had the same profile?

Force = mass x acceleration. That's Newton's second law expressed as an equation. Increasing mass in your fist increases the force requires to stop it. However, that's not why it does more damage.

Damage to your body is done by applying a lot of sudden and extreme internal forces within your body. If you apply a force uniformly across your body, it's got to be gigantic to do much damage (like 10+ times your body weight). When that happens, the liquid parts of your body slosh around and break through membranes into the air-filled parts of your body like your lungs, eardrums, sinuses, et cetera. This is how an explosion's overpressure hurts you.

In the case of a gunshot, a bullet pushes your tissues aside as it passes through. Since Newton's first law (inertia/momentum) is a thing, these tissues continue expanding after the bullet passes through until their natural elasticity contracts them back again. This makes for a lot of force in a small area, leaving behind a wound channel of pulped tissues. Sharp weapons work in a similar way, but with less pulping and wider wound channels.

In the case of a blunt weapon like your fist, sudden compression of an area creates intense stress on bones and soft tissues where it hits, breaking the harder stuff and bruising the softer stuff. When you add to the mass or speed of the blunt weapon, you increase the force required to stop it.

What armor does is spread out the force of the weapon impact over a larger area. Just as much force is needed to stop an attack whether you're wearing armor or not, but spreading out those impact forces reduces or eliminates serious injuries. While there is a mild benefit to having heavy armor, that benefit only really kicks in if it's proportional to your body mass. Unless you're wearing more than 80 lbs or armor, its mass is far less important than its ability to spread out weapon impact forces. A super-light armor, properly fitted, doesn't need mass, since the body wearing it is generally much more massive than the armor.

[kiralon]

I found in this
https://www.palladiumbooks.com/index.ph ... Itemid=200
if found
192
What kind of negatives should be imposed if I were to cast the spell "increase weight" on a weapon being used in melee?

Answer: It all depends on how much weight is applied, if the weight added exceeds the characters carrying capacity, then it cannot be used in combat, but it can be used to increase damage since more force is applied behind it, though penalties to Strike, and Parry as well as throw may be applied.

So I would say yes (Was inclined that way already though)