When I walk from Mile End Road to Sainsbury's, I almost always walk in through the front entrance. When I leave, I leave by the side entrance. This despite the fact that I walk past the side entrance on the way in.

When I walk into university, I usually do so via Mile End Road and the little bridge you can just about make out on the map. When I walk home from university, I do so via Hamlet's Way and (sometimes) the park.

View Larger Map

As you can see, there is little to choose between these two alternatives in terms of distance (actually, there's probably more to choose between them than I would have guessed - the park seems to win quite clearly) but it seems that there is a pretty regular bias that makes me choose one in one direction and one in the other. There are several other places where I've noticed this phenomenon.

Now, I know that there are lots of situations in which the fastest way from A to B is not the fastest way from B to A, even when walking, but I pretty sure this doesn't explain what's going on here. There's some sort of heuristic governing my decisions, and I can't quite work out what it is. It seems to be something like "if you know you need to turn, do so early". Why am I doing this? Does anyone else do the same thing? Have other, more bizarre heuristics?

## Tuesday, 31 August 2010

## Sunday, 15 August 2010

### Tube or False (or just nonsense)

There is a new advertising campaign on the London Underground... I'm not entirely sure what it's advertising, as everyone who sees the posters is already on the Tube and presumably already aware that it exists. Anyway, the campaign is entitled Tube or False, and consists of 8 statements about the system for us to guess whether they are true or false.

One of these is:

One of these is:

Every week, our escalators travel the equivalent of 2 times round the world.I'll post a spoiler under the fold, but pause for a second to decide if you think that's plausible.

## Saturday, 14 August 2010

### The Handshaking Lemma

Professor Geoffrey Beattie of the University of Manchester has given us mathematical formula for the perfect handshake. For some reason, all of the articles which contain said formula seem to include it as a picture, rather than writing it out in words, so I'll do the same thing (mostly because I don't know how or if it's possible to get LaTeX to work in blogger... does wordpress do it?

Just in case you're wondering what all those symbols mean...

Just in case you're wondering what all those symbols mean...

*(e) is eye contact (1=none; 5=direct);**(ve) is verbal greeting (1=totally inappropriate; 5=totally appropriate);**(d) is Duchenne smile - smiling in eyes and mouth, plus symmetry on both sides of face, and slower offset (1=totally non-Duchenne smile (false smile); 5=totally Duchenne);**(cg) completeness of grip (1=very incomplete; 5=full);**(dr) is dryness of hand (1=damp; 5=dry);**(s) is strength (1= weak; 5=strong);**(p) is position of hand (1=back towards own body; 5=other person's bodily zone);**(vi) is vigour (1=too low/too high; 5=mid)**(t) is temperature of hands (1=too cold/too hot; 5=mid);**(te) is texture of hands (5=mid; 1=too rough/too smooth);**(c) is control (1=low; 5=high);**(du) is duration (1= brief; 5=long).*## Wednesday, 11 August 2010

### A Tiling Problem

A while ago, Andy and I were at a maths challenge. There were a few problems with the answers we'd been given to the questions. Andy has already documented one of them, I'm going to comment on the other.

Here's a tiling pattern (imagine, if you will, that it was drawn by someone more competent than me, so all three polygons are regular every time they occur):

Now imagine that we use this pattern to tile the entire plane - so that we can ignore what happens at the boundary. The question is: what is the ratio of hexagons to squares to triangles in the final tiling (actually, the question was "what is the ratio of squares to triangles?", but you might as well do all three). The answer is probably not what you think immediately.

Here's a tiling pattern (imagine, if you will, that it was drawn by someone more competent than me, so all three polygons are regular every time they occur):

Now imagine that we use this pattern to tile the entire plane - so that we can ignore what happens at the boundary. The question is: what is the ratio of hexagons to squares to triangles in the final tiling (actually, the question was "what is the ratio of squares to triangles?", but you might as well do all three). The answer is probably not what you think immediately.

## Friday, 6 August 2010

### Not from The Onion

Stolen directly from Marginal Revolution, but how can I not share this?

PS - I'll write the stuff about the inefficiency of queues when I get round to it - very possibly in the next week or so.

I'm not quite sure why Tyler didn't list it under "not from the Onion"## Japanese macaques will completely flip out when presented with flying squirrels, a new study in monkey-antagonism has found. The research could pave the way for advanced methods of enraging monkeys.

PS - I'll write the stuff about the inefficiency of queues when I get round to it - very possibly in the next week or so.

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