Sunday  31 Mar 2013           comment?

"Mathematics may be defined as the subject in which we never know what we are talking about..."   — Bertrand Russell

"I consider that music is, by its very nature, essentially powerless to express anything at all..."   — Igor Stravinsky

Stravinsky later said he'd prefer to phrase it as "music expresses itself".

Saturday  30 Mar 2013           comment?

The first (yes, there will be more) in a series of snippets of dialogue I'd like to see in a movie:

phone rep:	You can fax us the completed forms.
customer:	Faxes are so twentieth century. Can I scan and email them instead?
phone rep:	We don't accept forms by email. You can fax them or mail us paper copies.
customer:	I hate faxes. I'll mail them to you.
phone rep:	Sir, mail is nineteenth century.
customer:	Yeah but I like the number nineteen.

Saturday  23 Mar 2013           2 comments

Samples from two music symbol fonts. On the left, the font provided with the free software (GNU Lilypond) I use to typeset scores. On the right, symbols from a score typeset with a well-regarded $600 product. The symbols on the left look nicer to me. To be fair, I imagine the commercial tool lets you change fonts to suit your taste. But one of the first things I noticed when I started using the GNU tool was how nice the symbol font was.

Friday  22 Mar 2013           comment?

A year ago, I wrote I'm not averse to art that is all in the concept and doesn't exhibit painterly (or other artistic) technique

and an example of such art came to my attention recently: a brass rod, 5 cm in diameter and 1 km tall, embedded in the earth with its top flush with the surface. Yes, I like a big brass rod in the ground more than I like a big granite rock above the ground. Go figure. When I first heard about Vertical Earth Kilometer, I wondered how the brass rod was joined. I was hoping it was welded, but alas it is screwed. I like it better than Levitated Mass anyway. The density of brass varies with the specific alloy; I estimate the kilometer-long rod weighs about 19 tons*. I would've liked to have seen how they gripped it while lowering it into the ground.

*19 US tons; about 17000 kg Photo by Daquella manera, used by permission under CC by 2.0 license.

Thursday  21 Mar 2013           comment?

I'm back home from a short trip to Colorado.

I get a different feeling arriving somewhere depending on the mode of transport. Whereas arriving on foot feels like I've come to a real place, driving or flying leaves part of me unconvinced. Arriving by bicycle feels as real to me as walking, not just because it's your own power but also because you're outside the whole time and the outdoors feels authentic.

And so it is that arriving at an airport without jetways makes air travel feel a touch more real.

Monday  18 Mar 2013           comment?

Advert stapled to a telephone pole in Los Angeles.

Saturday  16 Mar 2013           comment?

A marimba has a wood bar and a resonator tube for each note. You want the tube and bar to be tuned to the same pitch, otherwise the tube doesn't do much and the tone is thin.

Sadly, any tuning of bar and tube will match for only one temperature. The bar elongates with increasing temperature and its tuning goes flat; the tube, on the other hand, goes sharp as the speed of sound in air increases with temperature.

After that came to my attention I got curious to find out what effect elevation (and thus air pressure) has on the speed of sound. I live at 4500' and all that. I found plenty of formulas on the web for speed of sound as a function of temperature, but not for speed as a function of pressure because pressure has practically no effect. Not what I was expecting.

Anyway. This has been a roundabout way of introducing an answer to the question from the previous posting, below. The sphere diameter has no effect on the ring volume. Rings of equal height will have equal volume. (Thanks to Keith Devlin, from whose web site I heard about this problem.)

Tuesday  12 Mar 2013           1 comment

Consider two napkin rings, made by boring cylindrical holes through the centers of spheres. The two spheres have different diameters but the diameter of the hole in each is chosen such that the two rings have the same height.

Which (if either) of the two rings pictured weighs more (if made of the same material)? I.e., which has the larger volume? Not that I recommend making napkin rings out of spherical forms, because—as appears on the cover of a record album I like—

Tuesday  05 Mar 2013           comment?

Clouds today.
And yes, I've put another 40× time lapse video on YouTube.