Archive for Focus

The Geometry of a Cricket Field

Posted in Cricket, Cute Problems, mathematics with tags , , on October 6, 2026 by telescoper

It’s been a busy day and I haven’t the energy for anything strenuous so I thought I’d put up a cute problem I was thinking about (for some reason) on the train home from Friday’s concert.

You may have to refresh your memory about units as well as the geometry of ellipses. The following picture will help:

According to Kepler’s First Law of Cricket, the boundary of a cricket field is in the shape of an ellipse, with the two middle stumps each marking one of the foci. These are 22 yards apart, defining the length of the pitch P. The distance from one middle stump to the square leg or cover point boundary is 65 yards. This distance, called S, is the semi-latus rectum of the ellipse.

  1. Derive a formula connecting the eccentricity e of the ellipse to P and S and calculate the value of e for the given values of S and P.
  2. Calculate the major and minor axes of the ellipse for the given value of S.
  3. Calculate the maximum distance from the stumps to the boundary for the given value of S.
  4. Calculate the area of the playing surface in acres for the given value of S.

The value of S given above is the minimum allowed for First-class Cricket. The maximum is 90 yards. Repeat Qs 2-4 for this value of S. (P is always fixed at 22 yds.)

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I’m Late, I’m Late…

Posted in Jazz with tags , , , , on January 12, 2021 by telescoper

It has been a long time since I last listened to the album Focus featuring Stan Getz on tenor saxophone so it was nice to be reminded of it when Bernard Clarke played the first track from that album on his show The Blue of the Night yesterday. I was listening when this track came up and I thought I’d share it here because I think it’s a cracker.

If you assume that a Stan Getz album from 1961 is going to be full of Samba and Bossa Nova tracks then you couldn’t be more wrong. This is an experimental album featuring Getz with a string orchestra. The suite of music for the album was originally commissioned by Getz from composer and arranger Eddie Sauter. Sauter’s orchestration did not include melodies for Getz. Instead he left spaces in the arrangements in which Getz would improvise.

The theme of the opening track, “I’m Late, I’m Late”, is nearly identical to the opening minutes of the second movement of Béla Bartók’s Music for Strings, Percussion and Celesta which Sauter intended the track as an homage. Not only the theme but also the broken rhythms and string orchestration definitely show the the influence of Bartók. One thing that struck me listening to this last night after not hearing it for a while is that it sounds very much like part of a movie soundtrack. Maybe it will be some day!

As an added bonus I’m Late, I’m Late also features the great  Roy Haynes on drums, but front and centre for most of the time it’s Stan Getz himself playing quite brilliantly.  In fact I’m told that Getz regarded this as his best album. Anyway, I think it’s great and I hope you enjoy it.

 

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