A car of mass m drives at speed v towards a concrete wall. Its kinetic energy is ½ mv2, and all of that energy is dissipated when it hits the wall.
Now consider an identical car driving at speed 2v towards the same wall. Its kinetic energy is ½ m(2v)2 = ½ m4v2 = 2 mv2 — four times as much as the original car, since kinetic energy goes with the square of the velocity. I hope that up to this point, all this is uncontroversial.
Posted in Challenges, Maths
As a long-time 2000 AD fan (I read it from Prog 1 and stayed with it for three or four years) I’ve been reading David Bishop and Karl Stock’s fascinating Thrill-Power Overload: 2000 AD — the first forty years [amazon.com, amazon.co.uk]. When I reached the section about the 1995 Judge Dredd film starring Sylvester “Rambo” Stallone, I was interested enough to watch it; and having seen that, I was interested to see the 2012 take starring Karl “Éomer” Urban.
So how do they measure up?
People talk a lot about “Internet monopolies like Google and Facebook”, as though they are the same kind of thing. Even as astute a commentator as Tim Harford (alias “The Undercover Economist”) lumps them together in statements like “Google dominates search; Facebook is the Goliath of social media; Amazon rules online retail”.
But these “Internet monopolies” actually fall into completely different categories.
Google dominates search because it offers the best general-purpose search engine currently on the market.
Posted in Culture, Very basic economics
From The Screwtape Letters: Letters from a Senior to a Junior Devil, written as a weekly newspaper column in 1941 and published in book form in 1942:
The whole philosophy of Hell rests on recognition of the axiom that one thing is not another thing, and, specially, that one self is not another self. My good is my good and your good is yours. What one gains another loses. Even an inanimate object is what it is by excluding all other objects from the space it occupies; if it expands, it does so by thrusting other objects aside or by absorbing them. A self does the same. With beasts the absorption takes the form of eating; for us, it means the sucking of will and freedom out of a weaker self into a stronger. “To be” means “to be in competition”.
Lewis puts these words in the mouth of his character Screwtape, a senior devil instructing his nephew on how to undermine a human’s progress as a Christian and as a person. They are intended to be too ludicrous to be taken seriously as anything but a satire of the most destructive and appalling philosophies on the market.
Yet somehow this has become completely conventional mainstream political theory in the UK, and now governs everything from how our universities and funded to the progressing privatisation of the NHS.
Discuss.
Posted in Books, C. S. Lewis, Life, Politics
I think most Leave voters now accept that leaving the European Union will hurt the UK economy. But a lot of people still feel that’s a price worth paying to regain control of immigration.
Brussels insists that freedom of movement is required if we’re to stay in the Single Market, but there may be some wiggle-room regarding exactly what “freedom of movement” means for us.
For one reason and another, I’ve been watching a lot of films recently. Here are the most recent half dozen, in the order I watched them, with brief comments on each. I have to say it’s been a good run: I really enjoyed all six.
A genuinely excellent film, though as always with all-time classics not quite as good as its reputation would lead you to think. Much hangs on the raw charisma of Humphrey Bogart (as Rick) and Ingrid Bergman (as Ilsa); Paul Henreid as Victor Laszlo radiates all the charisma of formica, but it doesn’t really matter because it’s kind of the point that Rick and Ilsa are magnetically attracted but she is bound to Victor.
Are you British? Yes?
Have you voted yet? No?
Then why the heck are you reading this, when you should be on your way to the polling station? GET OUT AND VOTE.
(I won’t tell you who to vote for. Not again.)
Posted in Politics
