Archive for November 29, 2020

Bill Bailey, David Olusoga & Michael Rosen head Beard of the Year 2020 shortlist

Posted in Beards on November 29, 2020 by telescoper

It’s almost time for the voting to start for Beard of the Year 2020. By virtue of being voted Beard of Ireland way back in March I qualified for the shortlist of eight. This year’s field is very strong, but I reckon I’ll be a good contender for eight place.

Voting this time will be via Twitter, as the following post explains.

Kmflett's Blog

Beard Liberation Front

29th November

Contact BLF Organiser Keith Flett 07803 167266

Bill Bailey, David Olusoga & Michael Rosen head Beard of the Year 2020 shortlist

The Beard Liberation Front, the informal network of beard wearers has announced the final shortlist for the Beard of the Year 2020.

The list consists of eight names after two ‘trim-off’ votes shaved the longlist of twelve names

There will now be two ‘Beard-Off’ votes for Beard of the Year 2020 which will open on 14th December and close on 22nd December. The winners of each vote will face each other for a final Beard of the Year vote on 23rd and 24th December.

Beard of the Year will be announced on 28th December.

BLF Organiser Keith Flett said, we’ve made some changes to the way the Beard of the Year vote runs for 2020. We’ve moved the vote to…

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A Problem of Resistance

Posted in Cute Problems with tags , on November 29, 2020 by telescoper

Bizarrely, last night I dreamt of this physics problem. This mean that I’ve seen it before somewhere, but if that’s the case then I’ve forgotten where. In the dream the problem of electrical resistance was muddled up with the problem of how to calculate the Euler Characteristic of a structure defined on a grid*, which is something I have used in the past. Anyway, with apologies for the poor quality of the drawing, here is the set up.

Twelve identical resistors R are arranged in four squares with common edges thus:

Yes, they’re meant to be identical squares!

What would be the effective resistance of this circuit measured between A and B?

Please post your answers through the comments box, with appropriate explanations. Bonus marks for elegant (i.e. short) solutions.

(In my dream this problem came up in contrast with the case where the four internal resistors and their connecting wires were absent, so the circuit was just a ring.  The Euler Characteristic of the original connected set of squares is 1 while that of the ring is 0, not that it’s relevant to the problem in hand!)