Altair_the_Vexed
2007-11-29, 07:48 AM
The players' characters in my party have a Portable Hole. As normal, it is listed as having an opening 6 feet wide, and 10 feet deep. I wonfered how much stuff they could fit in there, as they're piling in the armour, weapons, money and other assorted objects that aren't tied down in the dungeon they've been looting.
Consulting this article (http://www.wizards.com/default.asp?x=dnd/rg/20051101a)(link provided by the ever-helpful Lord Silvanos), I find that the Spoooky Wizards figured the volume out as 280 cubic feet (I got 282-ish, but what's 2 cubic feet between friends?).
The article goes on to say that 280 cubic feet can hold about 100,000 coins.
Hang on! 100,000 coins? I had to work this out.
Working backwards from 280 cu ft, we find one coin (assuming 100,000 coins fills the space) is 4.8 cubic inches - that's very large... If it were a quarter inch thick, it'd be 2 and half inches wide, for example. Nothing like the picture in the PHB, which shows a 1 inch diameter coin.
A 4.8 cubic inch coin would have a density of 2.6 kg/L (they're quoted as weighing one fiftieth of a pound each - but excuse me while I switcvh to scientific units for a moment for comparison), which is just 2.6 times the density of water, one seventh of the density of pure gold, less than a third the density of copper, and a lower density than aluminium...
What are they made of? Are they hollow? The only metals I can find of lower density are magnesium and beryllium, which aren't easy to make... Beryllium was first isolated in 1828, and Magnesium was isolated in 1808. The difficulty of getting these metals out of ores (including aluminium) meant that they were far more expensive than gold for a hundred years after their first isolation. Sure, we can get these metals with magic in D&D, but isn't that going to be more expensive than digging up, say, tin?
I reckon the figure quoted in that article is wrong. If the coins are - as shown in the PHB - about an inch in diameter and (let's say) a quarter of an inch thick, then you can fit just less than two-and-a-half-million in the portable hole (if you melted them to take away the empty space between the coins).
We know we have empty space between the coins, so two and a half million is too many. To account for the empty space, imagine they're cuboids with the same dimensions - a quarter inch thick by one inch square. That gives us room for 1.9 million coins. There'd still be some empty space, of course, they'd not be perfectly stacked, so let's call it 1.5 million coins.
That's 15 times more than the figure on the WotC site.
I'll admit my maths may be shaky, and my knowledge of heaping dynamics is only based on some speedy searches on the google academic pages, but a factor of 15 is a really big - and important - difference.
Have I got it all wrong? Is my ability to work out cylinder volumes in error?
Consulting this article (http://www.wizards.com/default.asp?x=dnd/rg/20051101a)(link provided by the ever-helpful Lord Silvanos), I find that the Spoooky Wizards figured the volume out as 280 cubic feet (I got 282-ish, but what's 2 cubic feet between friends?).
The article goes on to say that 280 cubic feet can hold about 100,000 coins.
Hang on! 100,000 coins? I had to work this out.
Working backwards from 280 cu ft, we find one coin (assuming 100,000 coins fills the space) is 4.8 cubic inches - that's very large... If it were a quarter inch thick, it'd be 2 and half inches wide, for example. Nothing like the picture in the PHB, which shows a 1 inch diameter coin.
A 4.8 cubic inch coin would have a density of 2.6 kg/L (they're quoted as weighing one fiftieth of a pound each - but excuse me while I switcvh to scientific units for a moment for comparison), which is just 2.6 times the density of water, one seventh of the density of pure gold, less than a third the density of copper, and a lower density than aluminium...
What are they made of? Are they hollow? The only metals I can find of lower density are magnesium and beryllium, which aren't easy to make... Beryllium was first isolated in 1828, and Magnesium was isolated in 1808. The difficulty of getting these metals out of ores (including aluminium) meant that they were far more expensive than gold for a hundred years after their first isolation. Sure, we can get these metals with magic in D&D, but isn't that going to be more expensive than digging up, say, tin?
I reckon the figure quoted in that article is wrong. If the coins are - as shown in the PHB - about an inch in diameter and (let's say) a quarter of an inch thick, then you can fit just less than two-and-a-half-million in the portable hole (if you melted them to take away the empty space between the coins).
We know we have empty space between the coins, so two and a half million is too many. To account for the empty space, imagine they're cuboids with the same dimensions - a quarter inch thick by one inch square. That gives us room for 1.9 million coins. There'd still be some empty space, of course, they'd not be perfectly stacked, so let's call it 1.5 million coins.
That's 15 times more than the figure on the WotC site.
I'll admit my maths may be shaky, and my knowledge of heaping dynamics is only based on some speedy searches on the google academic pages, but a factor of 15 is a really big - and important - difference.
Have I got it all wrong? Is my ability to work out cylinder volumes in error?