Here's the science

[in4]

Olympic cycling etc. from the Open University; for all the helmet wearers amongst us! 

http://www8.open.ac.uk/choose/ou/engagement-cycling?ONEML=enq44p&MEDIA=enq44prp_eml12

[John Saxby]

Great stuff!  OU's a great source for all sorts of things -- thanks. 

Didn't hear the word "fun" intrude, though, as in, "Are we having fun yet?" Or, "C'est pas fun."  Nor "beauty".  But then, I was looking only at vid #2 -- will check the others.

J.

[JWestland]

The OU DVDs I have for Maths (M208) digitized from videos from the 80s crack me up every time.

The geek is ueberstrong in them.

OU is great BTW I am doing a part-time BSC in computing and maths with them. No way I could do it w/o the flexibility OU offers.

[Andre Jute]

Most people in the UK, and elsewhere that the Freeview channels are available by satellite (and in the States via PBS), owe at least part of their further/adult education to the Open University, often without realizing they're being educated. Many, many of the programmes on BBC TV channels Three and Four in science, history, social commentary, literature, drama even, cosmology, physics, art, all kinds of interesting stuff, is in fact OU materials. Watch the credits at the end, and you'll discover you've been watching the most entertaining study materials ever made.

Andre Jute

[ians]

Most people in the UK,  .... owe at least part of their further/adult education to the Open University

Andre Jute

So true.  I left school without any formal qualifications and the OU educated me (I was one of the early students, watching science experiments on a B&W tv).  Then in the early 1980s I managed to get a job as a BBC producer making ..... TV programmes for the OU.  Although we had moved on to colour by then.  And then came the video cassette!! Wow - now our lives would change forever.  Once we had the video cassette we could do all sorts of things that were just not possible with broadcast tv. 

I got to meet and make programmes with some amazing people - including a young James Dyson in his workshop - where he had made over 2,000 models of a cyclone (in brass) in order to perfect his crazy idea for a bag-less vacuum cleaner.  (I also got to interview the marketing manager of a major vacuum cleaner company who said it would never catch on).

But one of the highlights was to work with a team from the University of Nebraska (and Kansas) in the early 1990s on an international project for first year undergrads across the globe, called The Bicycle in Science, Technology and Society.  They included some big names from the world of bicycle science, (e.g. David Gordon Wilson and Chester Kyle) and although they got some US and EU funding, the project staggered as is often the way with these things when those with the money could not understand how you could use something as simple as a bicycle to teach some fundamental physics and materials science.  The simplicity and accessibility of the bicycle to educators (particularly those outside the US and UK) was lost on them.

I'm long since retired from those days, but I was lucky - the OU not only educated me - it also gave me a wonderful job. 

ian

     

[Andre Jute]

That's a wonderful anecdote, and CV, Ian!

Andre Jute

[John Saxby]

OU is a great institution--one of the UK's outstanding contributions to adult education and citizenship. I'm privileged to know a couple of people who have taught with OU -- and now, at a distance, Jawine and Ian too. Well done to you both!

J.

[JWestland]

I found a bicycle wheel excellent to illustrate Group Theory (symmetry groups) and specifically elements g in group G that are Generators, eg repeat application of their group operation (f.e. rotation) creates G.

Leaving aside logos etc. a bikewheel with 36 spokes is more or less symmetrical on rotation. With 18 spokes on each side, each spoke rotated by 2PI/18 can be place in the position of all the other spokes and thereby on rotation can "generate" the whole wheel.

Is that snoring from the back of the lecture theater?

[JimK]

I like thinking about symmetry groups and bicycle wheels!

But I am not so sure about 2 * pi / 18!

If the wheel is laced radially, that seems right. But if the wheel is laced tangentially, then half the 18 go off the hub clockwise and the other half go counter-clockwise. So maybe 2 * pi / 9 is closer.

The fun thing, too, is that one can flip the wheel over. So it seems like a group with two generators, one of order 2 and one of order 9.

[Andre Jute]

Really small things amuse great minds. -- 101 Things Albert Einstein Never Said

[JWestland]

Nods wheel lacing comes into play.

Pedantry alert: An element g of group G is a generator if g has the order of G.
So you can't have order 2 and order 9 generators for the same wheel.

I guess you meant you need to rotate either 2 or 9 times?

Hobbes Einstein wasn't easily amused, was he? 

[Andre Jute]

Hobbes Einstein wasn't easily amused, was he? 

Truth is, I don't know. But I wouldn't be surprised if dear old Albert had a good sense of humor. Otherwise, how did he stay sane for forty years while he searched for and failed to find the Grand Unified Theory?

But I'll distract you with another piece of trivia: Karl Marx, a most ugly man, was very successful with women because he had such a good sense of humor. Absolutely true, and verifiable.

Andre Jute

[JimK]

I think the total group is a product of two subgroups, one of order 2 and one of order 9. The order 2 subgroup is where you flip the wheel. I guess that only works on front wheels... that don't have disk brakes!

Gets me thinking about wheels where the two sides aren't laced the same. Of course rear wheels are most commonly dished. But, .e.g. the torque on the rear wheel always goes the same way... maybe one could have 24 spokes taking that torque and only 12 to pull the other way?

Shakespeare always had that follow through punch line, e.g. "and fools seldom differ!" Maybe Einstein did too. Perhaps too kind to say it though!

[JimK]

Ha! Group theory!

Suppose a*a = 1 and b**9 = 1. In a commutative group.

Then (ab)*9 = a. It's looking like ab is actually a generator! (ab)*10 = a*b*(ab)**9 = a * b * a = b.

So one can generate the whole symmetry group of a 36 spoke tangentially laced wheel with the generator that flips the wheel over and rotates 1/9 of the circle. Two such moves should put the wheel back in the first orientation but rotated 2/9 of the circle.

Rusty gears up there. Regular lubrication has been neglected!

[JWestland]

OK so a is self-inverse (as a*a = 1 which is e in multiplication)

Ah b is a wheel flip. We got taught a generator must be just one element, that keeps getting repeated.

So a wheel flip + rotation wouldn't be "legal" in math speak

I had to ignore quite a bit of things to get it to work maybe we need a wagon wheel