Personal Blogs

Here's a phot my brother took of a goldfinch

The name carduelis is Latin for something like "of the thistle" I think, because they are so fond of thistle-seeds but this one was amongst some forget-me-nots!

A friend sent me this picture of a Cornish forest.

Someone asked “What’s that funny hair on your upper lip?” I was like “Not got time to explain right now. Must dash.”

See 

Rachmaninov lived about 70 years, which is approximately 2.2 billion seconds. The quoted number of notes was 7.5 billion billion. So the composer would have needed to have written more than 3 billion notes for every second of his life.

I watched a YouTube video which said Rachmaninov wrote 7.5 x 10¹⁸ notes during his lifetime as a composer. Could this be true?

I only wish I could post the scent as well as the picture.

See https://learn1.open.ac.uk/mod/oublog/viewpost.php?post=260011

I found this in a puzzle book and thought it would be not too hard, but it was more tricky than I expected. Making sure you haven't missed any triangles, or double counted any, is quite slippery.

Here are the possible kinds of triangle:

Each of these can occur in five positions, so I thought at first the answer is 6 x 5 = 30, but I was mistaken, because config. e has chirality, i.e. handedness; the triangles can be aligned right or left, and so we get a total of 35.

After more investigation I found a fairly recent paper which gives a general formula for a regular polygon with any numbers of sides, but for larger numbers it gets quite complicated. 

I liked this problem, for the original pentagonal case, because it is easy to grasp, less simple than appears at first but is still solvable with some careful working.

I'll post a link to the paper about the general case for anyone interested.  

How many triangles can you find in this diagram? I don't just mean ones whose vertices liu on the outer pentagon, I mean all the triangles visble.

Nominative determinism is the idea that a person's name might somehow influence their career choice. 

The term was popularised in New Scientist magazine in 1994, and was intended humorously. It attracted many examples, such the book The Imperial Animal by Lionel Tiger and Robin Fox and Pole Positions—The Polar Regions and the Future of the Planet, by Daniel Snowman. You can find lots of similar examples in the Wikipedia article here.

There is even an intriguing possibility that is it more than a series on coincidences, that these is really something in it, and it has been seriously discussed by a number of psychologists, although it would be hard I think to0 establish any real effect.

Be that as it may, I have just been reading the history of Anglesey Abbey in Cambridgeshire and in the Wikipedia article about it I came across this advertisement from 1926. Bidwell and Sons auctioneers, eh?