Not quite Harry Potter (but with science and robots!)

(Okay, so I chose that title because the pi-effect has worn out…)

I don’t remember where exactly, probably on one of the physics blogs in the Mixed States collection, but some time ago I found a link to this comic about the adventures of an inquisitive girl in a mysterious school. Forbidden woods, ghosts, strange events happening, secrets from the past… and science projects and robots, too.

If this sounds like fun, check out Grunnerkrigg Court (that’s a link to the first episode). I’m not usually a comic reader, or a fantasy fan, but I’m hooked.

Filed under: Comics, Education, English, Hands-on math & science

TASP – de Siddebuurse bok

Deze week een wiskundig gedicht, dat ik nog ken uit mijn wiskundeboek van de middelbare school (Getal en Ruimte). Met dank aan Peet die het in een reactie op het QED-gedicht suggereerde.

Op een bok

Te Siddeburen was een bok
die machtsverhief en worteltrok.
Die bok heeft onlangs onverschrokken
de wortel uit zichzelf getrokken
waarna hij zonder ongerief
zichzelf weer in ‘t kwadraat verhief.
Maar ‘t feit waardoor hij voort zal leven
is dat hij achteraf nog even
de massa die hem huldigde
met vijf vermenigvuldigde.

Kees Stip

Filed under: Nederlands, TASP

Hiep hiep hiep…

Hoera!

De wiskundemeisjes hebben maar liefst twee Dutch Bloggies gewonnen – voor best geschreven weblog en voor beste themaweblog.

Gefeliciteerd, dames!

(Ik voel me extra trots omdat ik anderhalf jaar geleden een mailtje van Ionica kreeg met de vraag hoe dat nou ging, zo’n weblog, en dat ze erover dacht ook te gaan bloggen, met een collega-wiskundemeisje…)

Filed under: Math, Nederlands

Double torus

Because Wilfred asked and I liked the idea, here’s a double torus. Made from a single thread.

Filed under: Crochet, English, Hands-on math & science, Math

TASP – Spring and Music walk together

It’s time for another spring edition of Tuesday Afternoon Science (and mathematics and education) Poetry.

So, as an exercise for the reader^*: where is the scientific component in this poem?

Spring and Music

Spring, among her sylvan shades,
And the gladness of her glades,
Once in dreamy hours was straying,
Where sweet Music with her throngs
Of glad melodies and songs
In the happy vales was playing.

Pan beheld the fairy maids
As they gamboled in the shades,
And he swore they should not sever.
But that o’er the blooming land,
Heart to heart and hand in hand,
They should wander on forever.

Thus when come the gentle days
O’er the wildwood’s tangled ways,
There is found no gloomy weather;
For among the leafy bowers
And the valleys bright with flowers
Spring and Music walk together!

Freeman E. Miller

(A book with many poems, including this one, can be found at the Gutenberg project.)

^* Anyone who’s ever used a mathematics textbook will get this joke, I think…

Filed under: English, Music, TASP

Seifert surface in crochet

As I mentioned in a comment to the post on the 3-4-5, my latest project in crochet is a so-called Seifert surface, a surface with a knot as its edge.
I came up with the idea from a picture of the Seifert surface of a trefoil I found here. A Moebius strip is another example of a Seifert surface, although its surface is not really a knot – but the ‘un-knot’, a loop with a twist.

For the moebius strips I made before, I started in the middle, with a loop with a half twist. After that first loop, every next line of stitches goes round twice, on both sides of the center string.

But now I thought you could also start on the outside, with the edge of the moebius strip (it has only one edge, of course) and work your way in. The edge is just a loop, no knots, but to make it work you need to give it two complete twists. (Remember that when you cut a moebius strip in half over the center line, you get a loop with two turns in it.) After closing the edge with the turns, work your way in until the width of the strip is half what you want the moebius strip to be, then end with the center loop connecting the frontside with the back.

That was not too hard, and actually great fun (I know… I’m probably a crochet-nerd). Next I wanted to do the trefoil. First I used the picture from the blogpost as an example. That worked (although I made a mistake and twisted one of the bands the wrong way), but I didn’t really like the result. The circles on top and bottom are there for no good reason and just obscure the structure.

So I tried the same method I used for the Moebius strip and started from the edge. The edge is a trefoil, the simplest knot you can think of, and it needs three twists. (I had to use some paper strips to figure out the right combination of the orientation of the twists and the knot.) It would have been clever to count the stitches of the first loop, the edge, and make sure they’re a multiple of six, but I didn’t. So one of the arms is 17 stitches long, and the others 18. It did work out pretty well with the different colors being ‘localised’ more or less.

Anyway, it was quite a puzzle, but in the end it worked out. The pictures prove it.

Filed under: Crochet, English, Hands-on math & science, Math

Waves vs Particles

The ScienceBloggers have written a load of posts on ‘basic ideas’ and now they’re having a competition to find out who is champion, Evolution or Pooper, Newton’s second law or Dark matter. From Uncertain Principles comes the following:

Also in Erdos subregional action, defending QED Conference champion Particle and star striker J.J. Thomson met up with their old rivals Wave and their Player of the Year candidate, G.P. Thomson. These two teams plain don’t like each other, and the game got off to an ugly start. Particle coach Louis De Broglie filed a complaint before the game, arguing that Wave’s famous delocalized zone defense was a violation of ISCL rules. Wave coach Louis De Broglie replied with a complaint of his own accusing Particle players of moving backwards and forwards in time, and claiming that it’s ridiculous to have the same person coaching both teams. Asked for a decision, league commissioner Richard Feynman shrugged, said “It’s just one of those things,” and wandered off to play the bongos.

As they say: go read the whole thing.

Filed under: Education, English, Quantum, Science, Second-hand blogging, Sillyness

Krosjee

… zo spreek je het Engelse woordje “crochet” – haken in goed Nederlands – uit, weet ik sinds gisteren. Alsof het Frans is, of in elk geval Frans zoals uitgesproken door een Engelsman.

Net zoals Bucket klinkt als Bouquet, merkte mijn kamergenoot Bart op. Oja. Tuurlijk. Logisch.

Filed under: Crochet, Education, Life, Nederlands

Ten random facts about pi

1. It’s Pi-day today!
2. Maybe they were preparing festivities… anyway, lately the number one search term for people coming to Qulog is Pi Song.
3. As a result, the stats on that post have gone up from maybe four every day to over yesterday!
4. There are seconds in a year (error is less than a percent).
5. You can ‘measure’ by repeatedly dropping a needle onto a ruled surface. It’s not a very practical way, but I like it anyway.
6. Somewhere in the digits of is my birthday. (But where? I always forget.)
7. A circle with diameter 1 has circumference and surace area .
8. During a lecture on quantum field theory, Gerard ‘t Hooft once joked that he used the ‘small circle approximation’: .
9. There are more pi-songs than just the one I wrote about last year.
10. Oh, I almost forget: , followed by a lot of digits I don’t remember…

Filed under: Education, English, Hands-on math & science, Math, Qulogistics, Random 10s

Milestone

Filed under: English, Qulogistics