He stopped at 3 seconds, damn.
This is a problem that I proposed for IMO 2011. It ended up in the IMO Shortlist, a set of 30 problems selected by the Problem Selection Committee from the 142 proposed problems from around the world. The IMO Jury then deliberated on the IMO Shortlist to select 6 problems for inclusion in the actual IMO paper (I was in the Jury too). Eventually the problem did not make it to the IMO, but I am proud of this nice little problem:
Source: IMO 2011 Shortlist.
Solution in this file: http://www.imo-official.org/problems/IMO2011SL.pdf
From Tanya Khovanova’s blog — one of my favorite math blogs. Do visit if you like math.
Once when I was working at Telcordia, I received a phone call from my doctor’s office. Here is how it went:
— Are you Tanya Khovanova?
— You should come here immediately and redo your blood test ASAP.
— What’s going on?
— Your blood count shows that you are dead.
— If I’m dead, then what’s the hurry?
Given that I wasn’t dead, the conclusion was that there had been a mistake in the test. If there had been a mistake, the probability that something was wrong after the test was the same as it was before the test. There was no hurry.
I love Evgeny Morozov. He writes eloquently what non-Facebook-using, non-smartphone-using, sick-of-technology guys like me feel deep in our hearts.
Behold his latest smackdown.
Future Shlock: Meet the two-world hypothesis and its havoc
The sewing machine was the smartphone of the nineteenth century. Just skim through the promotional materials of the leading sewing-machine manufacturers of that distant era and you will notice the many similarities with our own lofty, dizzy discourse. The catalog from Willcox & Gibbs, the Apple of its day, in 1864, includes glowing testimonials from a number of reverends thrilled by the civilizing powers of the new machine. One calls it a “Christian institution”; another celebrates its usefulness in his missionary efforts in Syria; a third, after praising it as an “honest machine,” expresses his hope that “every man and woman who owns one will take pattern from it, in principle and duty.” The brochure from Singer in 1880—modestly titled “Genius Rewarded: or, the Story of the Sewing Machine”—takes such rhetoric even further, presenting the sewing machine as the ultimate platform for spreading American culture. The machine’s appeal is universal and its impact is revolutionary. Even its marketing is pure poetry:
On every sea are floating the Singer Machines; along every road pressed by the foot of civilized man this tireless ally of the world’s great sisterhood is going upon its errand of helpfulness. Its cheering tune is understood no less by the sturdy German matron than by the slender Japanese maiden; it sings as intelligibly to the flaxen-haired Russian peasant girl as to the dark-eyed Mexican Señorita. It needs no interpreter, whether it sings amidst the snows of Canada or upon the pampas of Paraguay; the Hindoo mother and the Chicago maiden are to-night making the self-same stitch; the untiring feet of Ireland’s fair-skinned Nora are driving the same treadle with the tiny understandings of China’s tawny daughter; and thus American machines, American brains, and American money are bringing the women of the whole world into one universal kinship and sisterhood.
“American Machines, American Brains, and American Money” would make a fine subtitle for The New Digital Age, the breathless new book by Eric Schmidt, Google’s executive chairman, and Jared Cohen, the director of Google Ideas, an institutional oddity known as a think/do-tank. Schmidt and Cohen are full of the same aspirations—globalism, humanitarianism, cosmopolitanism—that informed the Singer brochure. Alas, they are not as keen on poetry. The book’s language is a weird mixture of the deadpan optimism of Soviet propaganda (“More Innovation, More Opportunity” is the subtitle of a typical sub-chapter) and the faux cosmopolitanism of The Economist (are you familiar with shanzhai, sakoku, or gacaca?).
More at the link above.