Tuesday, December 09, 2014

Science and Policy - Why should they pay attention to us?

Reading the latest CSAP (center for Science and Policy) report on "future Directions for Scientfic Advice in Whitehall" is quite frustrating if you are a geek.

Several behavioural weirdnesses define geeks, and these matter:

  1. geeks tend to read about anything whatever their core training is, whether climate science, social media analytics, psychology, behavioural economics, and XKCD
  2. notwithstanding Steve Hand's memorable pub rant[1], politics appears to be quite a lot simpler than a physics (Natural Sciences) or computer science or engineering degree, really.
  3. they witness many people in political decision making roles who are actually less qualified even in terms of soft (social) sciences (lets not rehearse the PPE pub rant again just yet [2])
So what does this lead to?

  1. incredulity when governments do not act on scientific advice (drugs, immigration, climate).
  2. frustration when governments offer explanations as to why they cannot act on said advice.
  3. strong inclination to walk away from bothering ever again to offer advice/evidence.
Far from this being something scientistcs should apoligise for, given the nature of the public's alienation with current western democratic policies (e.g. economics of austerity), it behoves politicians to rethnk how they react to public advice:

  1. scientists have a methodology (atually lots, but lets stick with Popperian classical Object Knowledge for now).
  2. Theories are falsifiable - the latest theory is "best of breed", that's all its merit is.
  3. We dismiss theories when new ones come along that meet the criteria (better fit, simpler, more elegant -- pick any).
  4. We change our minds
Indeed, there are honourable occasions (e.g. discovering that stomach ulcers were caused by bacteria, or the italians finding that their neutrinos did not go fast than the speed of light, or the cold fusion fail), when this is very public, but it happens every day on a finer granularity

I think the time has come for scientific method to be applied by politicians. Just as Jeanette Wing argued for computational thinking to be part of everyone's intellectual landscape, scientific method has already been embedded in everyone's subconscious for some time (e.g. since the Age of Enlightenment, aka Age of Reason)

Why not? As Oliver Cromwell said to one government (and remember what happened to them 

Think it possible you may be mistaken.

Thursday, August 14, 2014



All bar one of the suspects was ruled out through a rigorous process of logic
and fermentation.  Suspect B was never identified, although her love of Citrus
flavoured chewing gum inclined Devonshire to discount her on the basis of the
lack of scent in any of the crime scenes. The fine detective had the measure
of Napier, and deemed his extremely asymmetric length arms to put him beyond
the reach of the law.  The recent Turkish immigrant who went by the moniker Moosh had an alibi (waylaid in a public loo by a nearly terminal bizarre
kebab accident). The Polis had no beef with Professor Baron, who was in any
case too absent minded to remember who could be next o nthe serial killer
list. Ms Bath was in the Ale House, where she tended to hang out with other
birds in hand. Dr Burleigh was too gentle a character, despite being a well
known Arms dealer.  The reverend Carlton was left handed, whilst the
Carpenters were both right handed, which saw them in the clear.
Thomas Champion was in london rowing, on the  Thames that day, and indeed,
had turned a corner since leaving the county seat for town, and given up his
unnatural addiction to Dobblers. (Dobblers is that well known breakfast dish
that looks like a classic grill, but in fact is made from dog & pheasant
and isn't as illegal as it is unpleasant).

The Earls of Beaconsfield and Derby were both out at a shoot, and so the
inspector was shot of them, even before five bells. Indeed, he thought to him
self with a wry ha-ha, pigs might fly and his golden hind come in, before
they'd commit any such gross moral turpentine. Henry was OK, since he'd made
peace with his Armenian girlfriend Ishca over the proper use of feathers in

It was known that Milton was blind drunk, and waxing eloquent over some
jolly waterman about his time playing frag piano in old Orleans.
The chancellor was above suspicion, as were any of the occupant of the
Regent house. All five of the Irish brothers were known to react badly to the
men in blue, a red rag to a bull, but the inspector rose to the challenge, and
avoided a crowning.  Rupert Brooke was with Milton the whole day, according
to the sheep rustler known to everyone just as The Eagle, who had dropped in
after some wild spread betting.

Radegund's sainted aunt claimed he was down at Ally Pally, his Alma mater, and
the only anchor in his peripathetic life.
The inspector would give drink bakers dozen once the moon was over the yard
arm if that blackamoor's head was capable of such dark thoughts.
Devonshire asked his trusty sidekicks Argyle and Clarendon if they thought
there was anything in the rumour about the boats? Dr A saw on the
British Queen not, whilst det inspector C, smelling like a
brewery concurred. Devonshire looked at these two interchangeable chaps, like
peas in a pod - you couldn't tell if you swapped them, castle-to-castle like.
He hadn't graduated in the Jubilee year to waste time like this. He had other
buns in the shop to fry.

Back in  Cambridge feeling blue drinking a hog's head of big black cow and watching the
cricketers cut down another elm tree, failing to impress, as they fought
by George to keep the greyhounds and haymakers at bay, Inspector Devonshire
wondered if perhaps the evil genius artist, Geldart was behind it all.
Granted, he had the locomotive and was a man with a means, if not completely
in a pickerel. After all, he was known to have a predilection for chasing the
Green Dragon down King Street at quite a run. Many times, Dr Kingston had
tried to wean him off, but he would claim to be a master of the Marinade,
although everyone knew he was just driving them up the Maypole.

So summing up the first victim, Panton was found  bashed in by a
globe carved curiously with Fleur De Lys; the second, Portland,
rolled around a Fountain, pursued by a green manatee. The third,
Ms Parrot, crushed beneath a free press, like grapes, blood
spoiling all the nice mitred corners, pouring out like an old spring, only
attractive to the rats. The fourth, Salisbury trapped between the mill stone
and a rock, but curiously tied up with rope and twine. The fifth was drowned
regally when his ship ploughed into a dead end.

At six bells, listening to Bert Jansch playing
down by black Waterside on his iPod, the inspector suddenly remembers Arthur C Clark's story from Tales from the White Hart
(the one with all the violations of Sir Isaac Newton 3 laws of droog).
he lit a fine Unicorn cigar with a White Swan vesta matches, and decided to
see if the Wrestlers were still slugging it out over a bacon, lettuce and
tomato roll. As seven starts came out, the inspector took the last tram home
but fell asleep and landed up in the depot once again.

Friday, November 29, 2013

principles of communications, 2013/2014, end of week #7 to L22

This week, we covered shared media & ad hoc capacity, and started on traffic engineering.

A sharp question on proportional fairness in earlier material prompted me to notice that that isn't well contrasted with max-min fair sharing -- It turns out (as often with technical areas) Wikipedia has a nice explanation - see this article on
proportionally fair w.r.t weighted (max/min) fair queues

Next week will finish traffic engineering and wrap up with summary of course.

Friday, November 22, 2013

principles of communications, 2013/2014, end of week #6 to L19

This week have done scheduling, queue management and switching
and just about to start on shared media

One interesting point historically -the colossus computer at Bletcheley Park built for code breaking was not a von Neumann classical architecture computer but was a "switched programme" machine  - this made it incredibly fast (for a 1940s design) although incredibly inflexible -- and it took a very long time for people to catch up on a standard desktop (about 50 years) - amusingly, about as long as the Dr Who series has run on BBC TV:)

Friday, November 15, 2013

principles of communications, 2013/2014, end of week #5 to L16

This week, control theory and optimization...

Some minor inaccuracies in slides have been corrected in the online copies linked from the course materials page...[or will be as soon as I can get powerpoint with the right fonts:) - the key error is in the calculation of the steady state error of the proportional controller - for some reason, there's a subtraction of the two terms for U(s) where it should be +
(KUs + Rc) / (s(s+K)
I think {need to check this:) it kind of makes sense (if the completion rate increases, the admission rate should increase....)

then when we take the limit of s(U(s), as s->0, we'll get Us + Rc/K
so ess (error in steady state) is Us - (Us + Rc/K) which gives us -Rc/K
(i.e. the answer is right, but the system response wasn't...will check and correct soon...

again, to note, the chapter on control theory in Keshav's book is very clear if you want alternative source + some nice example problems.

Friday, November 08, 2013

principles of communications, 2013/2014, end of week #4 to L13

Error, Flow and Congestion Control done (99.9%)

further reading - maybe - on Network Coding (see Digital Fountains)
and on what's in Linux (CUBIC) and Windows (Compound) for congestion control, and what real traffic actually looks like - see CAIDA

next week: control theory...and optimzation:)

Friday, November 01, 2013

principles of communications, 2013/2014, end of week #3 to L10

This week we covered routing -

there's one egregious error on the slide explaining Dijkstra's algorithm in Link State where the sign on the comparison is the wrong way round (well spotted students!) - I leave it as an exercise for you to find, as it makes for careful reading:-)

In Sparse Mode, we use Rendezvous Points to coordinate a single RPF tree around a designated/configured router (maybe one for each of a different block or subset of multicast addresses) - there's no guarantee the RP is in a sensible place, although the switch from RP centric tree to source based tree after an traffic flows helps reduce latency -  automatic placement of an RP to be in the "centre" of the group would be a solution to the Steiner Tree (Min spanning tree) problem which is NP-Hard, although there are polynomial time approximation algorithms for it (but you probably wouldn't deploy them in routers, but in a network management system for e.g. a gamer or trader network, this might be sensible)

One other note - consistency, symmetry of routes, and so on - IP and IP routing make no guarantees about this at all! BGP (inter-AS routes) are often asymmetric...recent computer science work on building new protocols that provide global consistency during route update and computation does exist, but is still research, largely....although the techniques are promising!

Next week, errors, then flow and congestion control.