Centrefuge at 15,000g
After yesterday’s Nuclear Power engineering lecture I asked the lecturer what he meant by “high g” centrifuges (which are used to seperate out the different isotopes of Uranium Hexaflouride. He told me he couldn’t possibly answer that (even though it’s in the notes as “many thousand g”). I felt this was a bit ridiculous because I felt that it would not be too difficult a thing to simply work out and. I figured that if it is something that I can work out for myself then he should be prepared to discuss it (as there is no real secret) and if, on the other hand, it is something I think I am able to work out but in reality I am missing something, then he should feel able to discuss that for educational purposes. The course is, after all, called “Nuclear Power Engineering”.
I admit that I find it tiresome when people act as if they are somehow on special Privy Council terms on matters of deep national importance. Especially if they have just undergone sixth form work experience or something similar. I remember people at school saying, “Oh I couldn’t possibly tell you that, it’s much too dangerous if it gets out. I’m trusted by her Majesty you know!” Give it a break you self-important phaffle-head! Yes some things need to be kept secret. Setting a scale of importance from one to ten: troop movements in Afghanistan being a Ten, the Cabinet minutes from the run up to the Iraq war being a three and the amount Britain knew about the torture practised by the Bush Administration being a one.
On that scale the discussion or otherwise of an aspect of physics with an interested undergraduate is well bellow zero and the same goes for most things people are asked to keep “secret”.
Most likely if you think you have been told some vital matter of national security then you’ve been placed “in the loop” to make you feel important. This probably accounts for 90% of “secrets” while 90% of the rest are doubtless things that might be embarrassing rather than dangerous, “Chris Galley” Stories, if you will. After that maybe 10% of the residue is actually troop movements in Afghanistan and if you know about them then, in the words of Sir Humphrey, you’ll be “keeping it secret that you hath the secret to keep” and you won’t be telling people how important you are.
Anyway, it turns out that , assuming that the UF6 gas remains at room temperature (and remains a near-ideal gas - big assumption!) then we would need the edge of the centrifuge to move at 400 m/s which is roughly Mach 1. This means that if the centrifuge had a two metre diameter then this would mean g forces of more than 10,000 g. Furthermore keeping the stuff at room temperature in such an environment might be tricky. Perhaps the non-idealness of the gas might help the enricher out quite a bit.
(Probably error ridden) notes are enclosed below.
ps
Isn’t the microsoft formatting just beautiful.
Squash Inspired Puzzle
Posted by george in George's Problems on March 10th, 2009
These puzzles were inspired by a squash match I watched earlier today. It was a best of five match and the Magdalene player was winning; two games to one. The opposition player put most of his remaining “energy” into winning the fourth game. In the event he put so much into winning that game that he was knackered by the time he got to starting the fifth (which the Magdalene Player won easily). The question occured to me as to how hard each player should be trying, how much of the kitchen sink to throw into the match and how much to keep in reserve for the possible fifth game (?).
A more well defined problem is this:
Two players are both given £100.00 to use in wining a contest which is conducted as follows: In the first round each player must pay as much or as little of his money into a box (unseen by his opponent) as he wishes to. The boxes are then examined by the umpire who awards a point to whoever paid the most money (ties are scored as half a point each). With whatever money each opponent has left a second round is conducted in the same way. Finally a third round is conducted in which both players will place all their remaining money into a third and final box. The winner of the third round is decided in the same way.
Imagine you are playing this game.
Clearly, since there is symmetry in the game, there can be no strategy that guarantees a win for one or other player.
But is there one which guarantees at least a draw?
Assuming the answer to this question is no (which I feel would not be hard to prove), is there an optimal (most likely probabilistic rather than deterministic) strategy that maximises the chance of winning the contest? (Strictly I would want to maximise the expected outcome of the contest for the player employing the strategy. A drawn overall outcome would count as half a win)
Clearly if the above strategy exists it will have an expected outcome of 0.5 or better against all other strategys including itself (against which it would score, on average, 0.5).
Problem:
Find such a strategy or prove that one does not exist!
For all I know these two problems might be among the hardest in Mathematics or they might have relatively simple solutions. (This is especially likely if the answer is that such a strategy can be proved not to exist which I think is likely to be the answer).
Finally, and I think more easily, if you could cheat by bringing extra money into the game how much extra money would you need, with a good strategy, to guarantee that you win the contest?
For this one can you think of a good bound and accompanying strategy?
Ivan Cameron (a pointer to an article by Charles Moore)
Charles Moore, in the telegraph, deals incredibly eloquently and sensitively with an emotionally prickerly matter; articulating the unease that he felt after the anomalous cancellation of Prime Minister’s Questions following the tragic death of Ivan Cameron.
I feel Moore is perhaps a little unfair in his assessment of Gordon Brown’s motivation, especially given Brown’s personal circumstances. A fairer assesement might be that offering to cancel PMQ’s was a fine gesture for Brown to make and equally it was fine for the Tories to accept but ultimately the Speaker made the wrong decision and should have allowed PMQ’s to continue without David Cameron.
Having said that this is by no means the worst decision the Speaker has ever made (see Speaker Michael Martin) and given the current controversies in which he has been embroiled it is understandable that he didn’t want to be seen to be standing simultanously asgainst govenment and opposition.
Moore acknowledges that the general public probably feel that Gordon Brown, William Hague and Vince Cable’s tributes to Ivan were a good display of adversaries coming together over something tragic which “transcended” the usual politicking.
If they are each to be rightly commended for this then surely the decision of Nick Clegg to say almost nothing in public but simply to send private condolences should also be commended as the most elegant and selfless of possible gestures that a party leader could make?
Speaker Micheal Martin
The mathematician G.H. Hardy once said that a “first class man” should never expresses a majority opinion as there will be plenty of other people to do that. Well here I am re-expressing the, now widely held, opinion that Speaker Michael Martin should soon step aside. Evidently I am not what Hardy would have called a first class man but then very few of us can be that.
For the small number of readers who are not familiar with the story of Speaker Martin I will briefly outline what he has brought to the office of speaker over the last nine years. (Yes a small number of readers can still be a majority since the blog only has a small number of readers – Us!)
The Speaker, once elected, is supposed to completely sever their links with their former political party and maintain the strictest impartiality. Prior to Michael Martin’s appointment there was a tradition of alternation between speakers from the two main political parties (remembering that until fairly recently the Lib-Dems would have had far too few members to wish to spare one to take on the role of speaker). The Speaker before Michael Martin was the highly esteemed Betty (now Baroness) Boothroyd who was a former Labour MP, although you would never have guessed it from the way she conducted herself in the chair. Consequently there was a perception among the more honourable honourable members that it was time to have a Speaker drawn from the Liberal or Conservative benches.
However the 1997 elected Labour back benchers, drunk on their hundred and eighty odd working majority decided to break with tradition, which is after all basically an evil, Tory, idea, and impose Old Labour loyalist Michael Martin upon the Speaker’s chair. He has remained the blunt class warrior that he was as an MP with a peculiar hatred of Tories, plumy accents and, no doubt, polo players! I should also mention that he is no Ramanujan, an aleph class man if you like, or a perhaps a first class Pig if the abuse of his parlimentary expences is anything to go by.
In his time as Speaker he has consistently shown considerable bias towards similarly aged, similarly scottish, similarly Labour back benchers and indeed anyone watching a rumbustious debate in the chamber will probably be able to infer, within half an hour or so, roughly where Speaker Martin’s sympathises lie on the matter.
Ultimately though it was the now well known events surrounding the arrest of Damian Green, along with the search of his parliamentary offices, that has brought him lasting shame and unequivocally made him the worst Speaker in living memory. Almost any other Speaker from modern history would have remembered Speaker Lenthall’s bravely spoken words of 1642 “I have neither eyes to see, nor tongue to speak except as directed by this house”. These words to a King, no less, who had entered the House of Commons in force accomponied by soldiers attempting to arrest five MP’s who has flown away.
Speaker Martin should have unreservedly apologised for letting the Metropolitan Police ransack Damian Green’s offices. He should then have done the honourable thing and immediately resigned and gone to the Lords (as do all outgoing speakers).
I recognise that there is generally too much clamour for people if public life to tender their resignations at the first hiccup in their term of office but this was such a grave error of judgement that he cannot possibly hope to regain even a sliver of the widespread cross party support which a speaker must retain in order to remain effective.
Instead Speaker Martin simply gave a mealy mouthed “apology” in which he tried to shift the blame to the sergeant at arms and the police saying that he “was not told that the police did not have warrant”. Many MP’s no doubt were left thinking, “Well frankly Mick you should have known; in the policeman’s professional handbook on page 1 is detailed, “How to use trickery to obtain permission to enter premises when getting a warrant would be judicially awkward.” If you didn’t realise that then you are even more of a Blubber-Brain than we had previously thought.”
Finally rumours are now flying around that Speaker Martin may not agree to step down, even at the next election, unless his son (currently a Labour MSP) is allowed to take over the Labour nomination in his seat of Glasgow North East.
What an ironic image that would be of the battle weary class warrior processing off in his ermine while his son assumes the hereditary constituency.
Estelle Morris and the Greater Good
Former education minister Estelle Morris is interviewed on the BBC today. Morris, now a peer, is able to talk candidly about her efforts to reduce British Truancy. Specifically she talks about the decision to allow imprisonment of the parents of children who persist in truanting (a practice that continues to this day).
When asked about whether this decision was right she says:
“If it worked it was worth it and if it didn’t then it wasn’t”
“I could never have got to the point where I said: I’ve done as much as I can. We’ll just have to leave it now”
These few lines really capture the essence of the role that New Labour politicians felt and still feel that government and the criminal justice system should play in society. There was obviously a Cabinet perception that the concerns of the greater good deserved more weight than they had been given prior to 1997 specifically when being weighed against the previously much stronger desire to ensure that people who had done little or nothing wrong didn’t go to jail.
The BBC also interviewed Emma Garza, one of the daughters of Patricia Amos, the first mother to be sent to prison in 2004 under the new rules. Garza obviously feels very strongly that her mother’s imprisonment massively changed her life for the better.
From what Morris has said I assume that she feels that the great good of improving Garza’s life in this way justifies any short term harm done to Amos. Perhaps Amos would even agree.
Nevertheless when asked about the merits of the policy Garza replies, “It worked but it wasn’t right, it wasn’t fair on my mum because she was trying her hardest to get me to go to school.”
Even this woman, who firmly believes that she gained life changing benefit from the imprisonment of her mother, realises that visiting the iniquity of the children upon the fathers and mothers is, and has always been, just as wrong as the converse. Mr. Balls and Straw surely it is about time this policy is dropped, whether or not it is effective.
The BBC links below will probably break in the next few weeks but for now the videos to which I am referreing can be found here:
Morris - http://news.bbc.co.uk/1/hi/education/7851367.stm
Garza- http://news.bbc.co.uk/1/hi/education/7883904.stm
Jim Knight and personal prejudice
The BBC ran a story today: “Education Minister’s Online Typos”.
Apparently Jim Knight (who incidentally once held the smallest ever parliamentary majority) has misspelled: receieved, maintainence, convicned, curently, similiar, foce, pernsioners, reccess and archeaological.
This reminded me of something my stepmother said; that we all suffer from personal prejudice and we delude ourselves if we think otherwise. I had thought this wasn’t true but hearing about these spelling mistakes did make me think slightly better of Mr. Knight, a clear case of personal prejudice!
Socks
Posted by george in George's Problems on March 10th, 2009
A problem from a book I read when I was small:
I have a draw with ten red socks and twenty black socks in it. how many socks do I have to take out (in the dark) in order to be guaranteed a matching pair of socks.
Answer: show
Conundrum
Posted by will in George's Problems on March 10th, 2009
You are driving in a car at a constant speed.
On your left side is a ‘drop off’, the ground is 18-20 inches below the level you are travelling on, and on your right side is a fire engine travelling at the same speed as you.
In front of you is a galloping horse, which is the same size as your car and you cannot overtake it.
Behind you is a galloping zebra. Both the horse and zebra are also travelling at the same speed as you.
What must you do to safely get out of this highly dangerous situation?
Answer: show
True Stories about Cambridge
1. The Queens College bridge was designed and built by Newton to be supported entirely by wood and nails. When scholars took it apart in the 18th century to see how it worked, they could not rebuild it correctly, and could only reconstruct it without the nails, using just wood and friction.
2. If you ride a suit of armour whilst wearing a white stallion, you may demand a Cambridge exam.
3. It is possible to walk from Trinity College Oxford to Trinity College Cambridge using land entirely not owned by either college.
4. There used to be a mini parked in Great Saint Mary’s court. One evening a group of Cauis’ students snuck in and built the entire Senate House beneath it.
5. There is a fully functioning market place hidden beneath Cauis College wine cellar.
6. Only the Queen can eat John’s College students, apart from on Christmas day, when swans are also allowed
Swan's are fucking evil.
7. Cambridge students often tell elaborate untruthful stories about punt tauts.
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