Wednesday, 28 April 2010

Sunday, 25 April 2010

Beauty at the LHC

Somehow this is so much cooler than writing specs in Alloy*...from El Reg, that bastion of scientific journalism and hats off the the scientists at LHC:
Beauty with antimatter bottom' created out of pure energy
By Lewis Page • 23rd April 2010 13:41 GMT

Physicists at the Large Hadron Collider (LHC), the most powerful particle punisher ever assembled by the human race, say that experiments there are going well. In particular, they have managed to create out of pure energy a thing which they describe as a "beauty" featuring an antimatter bottom.
Comes complete with the "Standard El Reg Disclaimer on Scientific Reporting" - on the otherhand El Reg does report science far better than nearly every other magazine and newspaper - electronic or paper based...
STANDARD REG SCIENCE QUALITY WARNING: The chance that we are following this correctly is roughly equivalent to that of a man with no arms throwing a handful of jelly through a falling doughnut at fifty yards without touching the sides
Anyway, here's the link to the LHC Press Releases which contains this:

21 April 2010: First reconstructed Beauty Particle

LHCb has reconstructed its first Beauty Particle! You can see below a computer view of this event in two projections (images on the left hand side). The Beauty Particle (called B+) is composed of an anti-quark b (that has a very short lifetime of 1.5 thousandth of a nanosecond!) and a quark u. It is produced by the collision of two very high energy protons from the LHC at a location marked as "Primary vertex", together with many other particles (shown in black). The B+ decays after travelling about 2mm into two particles (called J/ψ and K+) at a place marked "B decay vertex". The J/ψ particle decays in turn immediately into two long lived particles called μ+ and μ-. The μ+ , μ- and K+ are traversing the LHCb detector where the tracking system is used to reconstruct their trajectories with such a very high precision, that it is clear they do not come from the primary vertex. The fact that the reconstructed tracks do not cross exactly in two points reflects experimental precision of computer reconstruction. The real particle tracks originate at the two vertices. The images on the right hand side show the same event when the tracks from the "Primary vertex" are forced to come from the "Primary vertex".

*I happen to like Alloy as a specification language and tool ... probably one of the best of the bunch!

Monday, 19 April 2010

UK Election 2010

Now it gets interesting: Election 2010: Lib Dem policies targeted by rivals

with the Liberal Democrats actually showing around 30% of the popular vote and in some polls even in first place. However, in the UK's electoral system neither the head of state nor the upper house are voted for. Then there's the lower house which works on a first past the post system which produces a very skewed result - primarily because the the vote is for a constituency rather than a party; and the winning party then rearranges the constituency boundaries to its favour.

So, what happens if the Liberal Democrats win 30% of the vote, Conservatives 30% and Labour 30% with 10% going to Plaid Cymru, SNP and the other parties? According to the BBC's vote calculator the UK gets this:

Party, Popular Vote, Seats in Government, %age of seats
Labour 30% 315 seats (~48.5% of seats)
Conservative 29.9% 206 seats (~31.5% of seats)
LibDem 30% 100 seats (~15% of seats)
Other 10% 29 seats (~4% of seats)

*NB: figures are +/- 0.5%

Friday, 16 April 2010

We Own Your Soul

The dangers of not reading terms and conditions:
GameStation: "We own your soul"
Author: Joe Martin
Published: 15th April 2010

In a bid to prove that nobody reads the T&Cs of an online sale, GameStation added a new clause of their own...GameStation has today revealed that it legally owns the souls of thousands of customers, thanks to a clause it secretly added to the online terms and conditions for the official GameStation website.

The "Immortal Soul Clause" was added as part of an attempt to highlight how few customers read the terms and conditions of an online sale. GameStation claims that 88 percent of customers did not read the clause, which gives legal ownership of the customer's soul over to the UK-based games retailer.

Interesting not because they wrote such a clause - though I'm not sure of its legality: both Richard Dawkins and the Catholic Church would have something to say about its precise details, but rather the fact that we habitually agree to terms and conditions of software, eg: Windows 7, Windows XP without understanding the ramifications upon our personal privacy and rights.

Friday, 9 April 2010

Graph cohomology

Graph cohomology. Just a link for future reference (and a reminder to do a search), though this paper> looks interesting, especially the embedding graphs in Rn...

Facebook --- warning...

And the Wondermark permalinks
Finally, pornography in the original internet...     --- Morse code if you're wondering.


Clever little movie this - quite like the 2001 touch at the very end.

Uploaded by onemoreprod. - Independent web videos.

Thursday, 1 April 2010

Graphs and Topoi


In this paper we survey the fundamental constructions of a presheaf topos in the case
of the elementary topos of graphs. We prove that the transition graphs of nondeterministic
automata (a.k.a. labelled transition systems) are the separated presheaves for the double
negation topology, and obtain as an application that their category is a quasitopos.
Keywords: topos theory, graph theory, automata theory, transition systems

1 Introduction
Sheaf topoi are usually associated to continuous mathematics, such as differential or algebraic
geometry. Nonetheless, several (pre)sheaf topoi with simple (even finite!) base categories describe
fundamental mathematical objects such as trees and graphs. It has been suggested by
Lawvere [5] that these simple topoi have a rich combinatorial structure. Nonetheless, very few
results are known about them, and their internal workings seem to be mostly unexplored.