PDA

View Full Version : Weird question



JackRackham
2015-07-18, 02:14 PM
Anyone with a graduated cylinder want to figure out the volume of a standard-sized d20? Other dice?

I was looking at some steel dice and noticed the impressive feel of them (in terms of weight). It got me wondering how much it would cost to make them out of something really dense, but non-toxic, like Au or Ag. I would normally google around and do some math, but I can't find the measurements for a d20 anywhere and I don't have anything to accurately measure it. I figure if I can get the volume, I can get the weight/mass and then figure out the material costs.

Yora
2015-07-18, 02:23 PM
The culculation is here (http://www.wolframalpha.com/input/?i=regular+icosahedron&lk=1&a=ClashPrefs_*Polyhedron.Icosahedron-).

Though I have no idea how to read it. 2.181 is lacking a unit.

ExLibrisMortis
2015-07-18, 02:24 PM
This is a joke. (http://lmgtfy.com/?q=volume+of+an+icosahedron)

https://upload.wikimedia.org/math/a/5/b/a5b528b8672c58125f45dbae090d4026.png

@Yora: It is lacking a unit, because that's part of the input (alternatively, it was cancelled out on both sides). You're supposed to give the edge length with a unit. The volume is ~2.18 cubic edge lengths.

JackRackham
2015-07-18, 02:27 PM
As explained in the spoiler, I don't have a way to accurately measure, otherwise I could have calculated the volume myself. And I've tried googling. It's no use. It's too obscure and "volume" means too many things.

Also, doing the math to get the volume seems wrong to me, since it would be just SO easy to put some water in a graduated cylinder, drop the die in and the difference between before and after measurements is the answer. Only, I don't have a graduated cylinder...

Yora
2015-07-18, 02:28 PM
So if I take an edge length of cm, the volume will be in cm³?

Let's take a regular d20 rpg dice and a tape measure. Edge length is 1.4 cm, which gets a volume of 5.98657 cm³. A little less, because most dice have rounded tips.
Or slightly below 186.2g of gold.

ExLibrisMortis
2015-07-18, 02:31 PM
So if I take an edge length of cm, the volume will be in cm³?
Well, I sure hope you don't get inches :smallbiggrin:. Yes, your input is something like: 3 rat's tails, so the output is 2.18 * 3 cubic rat's tails

Akodo Makama
2015-07-18, 07:39 PM
Well, I sure hope you don't get inches :smallbiggrin:. Yes, your input is something like: 3 rat's tails, so the output is 2.18 * 3 cubic rat's tails

Actually, it's be:

2.18 * (3 rat's tails) ^ 3 = 2.18 * 27 cubic rat's tails

Don't forget to cube the scale factor.

ExLibrisMortis
2015-07-19, 09:56 AM
Actually, it's be:

2.18 * (3 rat's tails) ^ 3 = 2.18 * 27 cubic rat's tails

Don't forget to cube the scale factor.
Right, sorry about that. Forgot that it'd be assuming a side of 1 unit.

Jay R
2015-07-19, 06:54 PM
They aren't icosahedra, but these (https://www.orau.org/ptp/collection/consumer%20products/dudice.htm)may be the densest dice ever made. They are depleted uranium.

https://www.orau.org/ptp/collection/consumer%20products/dice.jpg

JAL_1138
2015-07-20, 12:02 AM
For when you absolutely need to pentrate Plot Armor.

Mr Beer
2015-07-20, 12:42 AM
They aren't icosahedra, but these may be the densest dice ever made. They are depleted uranium.


Awesome! Google-fu tells me they should weigh about 200 grams each, which is insane.

1 cubic inch = 309.715g. 7/8 of an inch cubed = 0.669922. So I make that about 200g.

Straybow
2015-07-20, 01:09 AM
"Densest" meaning you'd have to be dense to want to use them... the material is mildly radioactive.

Densest available is probably tungsten (http://www.dicecollector.com/THE_DICE_THEME_METAL_TUNGSTEN.html) and gold (http://www.dicecollector.com/THE_DICE_THEME_METAL_GOLD.html) (both 19.3g/cm³ > ~16g/cm³ for DU)
http://www.dicecollector.com/dice_MINT36_CYBERNETIC_RESEARCH_LABORATORIES_AMBER _RIX_MACHINED_PRECISION_DICE_TUNGSTEN.jpg
This gold set doesn't have a scale, but I believe them to be Crystal Caste minis. The d20 might only be a few kilobucks
http://www.dicecollector.com/dice_METAL_GOLD_MULTI_01_CRYSTAL_CASTE_01.jpg (http://www.dicecollector.com/METAL_GOLD_MULTI_01_CRYSTAL_CASTE_01.jpg)
Compare to this image:
http://www.dicecollector.com/dice_METAL_COPPER_MULTI_01_CRYSTAL_CASTE_02.jpg (http://www.dicecollector.com/METAL_COPPER_MULTI_01_CRYSTAL_CASTE_02.jpg)

Don't know about any platinum group metal dice that would be up over 20g/cm³

Crystal Caste makes a number of metal dice that will fit your bill