Entries by Tristram Brelstaff (2955)


Annular Solar Eclipse

While looking at Google Maps I happened to notice this black spot over the south Atlantic.  I immediately suspected that this must be Google being clever and showing a solar eclipse and, sure enough, Wikipedia shows that there is an annular solar eclipse in progress in that area at this very moment: https://en.wikipedia.org/wiki/Solar_eclipse#/media/File:Central_eclipses_2001-2020.png


Essence of Linear Algebra

I have just finished watching this excellent series of short videos by Grant Sanderson of 3Blue1Brown on the geometric intuitions behind linear algebra:

Essence of Linear Algebra

They remind me of some maths courses it took with the Open University 20 years ago but they included quite a few things that were new to me.  I particularly liked the matrix interpretation of the differentiation of polynomials in the last video.


Functional Programming Talks

In the past few months the following lectures have greatly helped my understanding of how algebraic structures can be used to design and construct functional programs:



A giant woodwasp, Urocerus gigas (Hymenoptera: Siricidae).  Actually not a wasp but a sawfly. About 5 cm long from the tips of the antennae to the tip of the ovipositor.

Specimen taken below Hangingstone, near Guisborough, North Yorkshire, UK, on 2016-08-23.


Another Soldier Fly

A female Oxycera morissii (Diptera: Stratiomyidae).

Specimen taken in Whiteknights Park, Reading, UK on 2016-07-10.