## 2005-02-02/

Up
```1889 is of Pete and Susan and Orinoco at home after an excellent roast pork
dinner, and reveals how Susan manages to stay so short.

1891 and 1899 and the videos 1896 and 1904 are of some of the party decorations
that Mike and Rick brought. I like the reflections they cast on the wall,
especially when they move in the hot air rising from the radiator.

1909, 1911 and 1912 are of Dave and me in the Prince of Wales in Highgate just
after our pub quiz. In my estimation round two teams out of six got no points
at all, and three questions out of ten were not answered correctly by any team.
Oops. Dave's rounds were good, though, and incorporated some of my questions,
honest.

1921 is of Dave's candle. 1922 and 1923 are of his computer, which has expanded
into a second cardboard box. Both were taken with flash, but 1922 was taken
with flash through my finger, so everything is blood-red. Doh!

1931, 1935, 1941, 1951, and 1954 are of my latest marble run, which
incorporates a horizontal loop-the-loop, and the videos 1924 and 1955 prove
that it works. The width of the track has to be horizontal at the beginning and
end of the loopy section but vertical in the middle, and in the transitions the
track has to take some very odd trajectories, which you can see best in 1954. I
eventually managed to find an arrangement in which most nearby bits of track
passed each other at one of the small number angles that the pieces offer.
However, you can see in 1954 that they do not make a simple angle to the floor;
the tower at the front has no foot and maintains its jaunty stance only with
the support of the track. Another constraint is that the marble is going quite
slowly by the end of the loopy bit, so the third loop has to be tight where it
is not angled slightly upwards, otherwise the marble will fall off. On the way
out there's no alternative but to build a straight section with a twist in it,
which you can see best in 1941. This explains the rather odd support which you
can see at the left of 1935 and at the bottom of 1951. That part took ages to
get right. The final constraint is that by the time the marble leaves the loopy
bit I've used up all the straight pieces, which means it must be going slow
enough to negotiate corners. Oh, and the muck on the carpet in the distance in
1941 is actually the piles of pennies I used as a tripod for 1924.

Good ones: 1889, 1954.
```

MVI_1896.AVI
MVI_1904.AVI
MVI_1924.AVI
MVI_1955.AVI