Looney Labs Icehouse Mailing list Archive

Re: [Icehouse] The original pyramid size formula revealed!

  • FromPat <xenophule@xxxxxxxxx>
  • DateTue, 6 Mar 2007 13:52:51 -0800
"And now you know ... the REST of the story. Join us next time when Andy tells us the stories NASA doesn't want us to know."


On 3/6/07, Andy Looney <andy@xxxxxxxxxxxxxx> wrote:
> > 3. I would bet that the Height(3)-Height(2)=Height(2)-Height(1) and
> >    Base(3)-Base(2)=Base(2)-Base(1) were intentional relationships.

If intentional, it was only intuitively so, at least at first. The smalls
are almost exactly the same size and shape as these 1-ounce lead fishing
weights I got in the late eighties, which formed prototype #1. The other
sizes started out arbitrarily bigger. The 3-ounce fishing weights weren't
big enough so Larges got bigger during the first few prototypes until they
"felt right."

> Nah, I don't think so. I suspect that the Small Height = Large Base and
> the (arbitrary?) Height = 7/4 Base was enough.

Actually, Small Height = Large Base was something we just noticed one day.
Sometimes things just work out magically, like the fact that 2 smalls
stacked are exactly as tall as a medium. That wasn't planned, it worked out
that way because of the wall thickness. The wall thickness was chosen to be
as thick as possible and still allow the pyramids to nest.

> Out of curiosity, does Andy get some perverse pleasure from watching
> us speculate about this trivia? Or is he utterly unaware that this
> is a repeating point of debate and contention?

Sorry I guess I didn't realize this was keeping people up at night... I
have a hard time keeping up with all the email, and I was thinking you-all
were just having fun yammering about equations that make my eyes glaze

> Yeah, I'm calling you out, bub! Pick one of those above, indefensible
> reasons for not telling us what the deal is; or spill it, Andy! ;)

OK, having been called out, I've dug into the oldest of files to uncover a
document vital to this conversation. It's called "An Odd Letter From Kit To
John," and it's dated 8 March 1990. Wow how time flies.

This is an amazing 5-page letter filled with hand-drawn diagrams and graphs
and charts and equations. Perhaps later I'll scan in and post the whole
thing. Here's how it begins:

"John: Since a few days after I got my Icehouse set, I've been wondering
what was on your mind as you determined piece size. I've come to the
conclusion that a small man on crutches helped you -- and he held one
crutch in his mouth and one under his arm and he computed pyramid size."

Now, remember, this was in 1990. The set he was evaluating was one of the
original 100 hand-poured plastic sets, not the factory-made stackable
beauties we sell now. The original pieces had Larges and Smalls that were
very close to the current standard, but the Mediums were too big.

The conclusion of Kit Cooper's memo is a set of recommendations for what he
thought we were after, and his calculations set the standard we now use. He

"Of course, it is obvious that possibility (2),(C) is the correct choice.
Not only do the pyramid Base Size and Face Height vary with a neat
equation: BS = 4 / 7 FH = (4 + (2 ^ (PointValue - 1)) / 8, but the pyramids
are similar too."

So there you go, the formula we used. I hope this clears things up. Sorry
about the angst.

-- Andy

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