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Pi Day Extraordinaire 107

First time accepted submitter DrTJ writes Today is Pi day. This year is a bit more extraordinary as it is 3/14/15 (in American date format). To celebrate, USA Today has posted a number of videos of kids reciting Pi, one of them to 8,784 digits. The Washington Post highlights the story of a couple who decided to make it their special day. "Donahue, 33, a Legal Aid attorney, fell for Karmel’s geeky side as soon as they met. On a beach vacation with her friends in 2012, a psychic told her, 'You are about to meet your soulmate.' Three days later, she walked into Kostume Karaoke night at Solly’s Tavern along the U Street corridor and saw a man onstage croaking out the Backstreet Boys’s 'I Want It That Way.' By the end of the night, he would be serenading her with Cake’s 'The Distance' — the song the DJ will play when they cut the pie."
Lord of the Rings

The Hobbit: the Battle of Five Armies Trailer Released 156

An anonymous reader writes: The first teaser trailer for the final installment of the Middle Earth saga, The Hobbit: The Battle of Five Armies, debuted at Comic-Con, and now Warner Bros have made it available online. While the trailer contains some nice shots on a visual level, very much in keeping with the Lord of the Rings trilogy, about 80% of the trailer's awesomeness is provided by the background music. Pippin's mournful song from Return of the King plays intercut with the doomed mission that Faramir leads on his father Denethor's orders.

Comment This is just one person's (Score 4, Informative) 202

personal opinion of the status of the various ideas labelled "multiverse", inappropriately presented as fact. There is certainly not a consensus view that these opinions are correct, as you might mistakenly infer. In fact, "..., with different Big Bangs but very likely with the same fundamental laws and constants" -- it seems to me the weight of professional opinion is actually more on the other side here. His views on Everett's many-worlds interpretation are also counter to those of most people who accept it as valid in the first place. Perhaps most egregiously, if he is going to borrow (linking to) Tegmark's categorization of the different levels of multiverse, he should at least get them right. But he refers to Tegmark's level 1 as level 0, level 2 as level 1, and is a little confused about the distinction between 1 and 2. If you want a much more thorough, and objective, discussion of the various multiverse ideas, you want to read Brian Greene's The Hidden Reality. And of course Tegmark's Our Mathematical Universe is the latest entry into this field, a manifesto of sorts.

Comment Re:Sudoku's complexity (Score 5, Interesting) 44

Generalized (NxN) sudoku is NP-complete. That's the only sense in which any puzzle is computationally intractable.

This is very fascinating work, but I am skeptical. I design puzzles like this, with computer assistance, and automatically gauging how difficult a puzzle is seems to be basically impossible. The fundamental problem is that the logical structure of a puzzle is not in itself sufficient to gauge difficulty. A huge amount of it is in the presentation, and how the player conceptualizes the puzzle, and how much of the problem can be handled automatically by visual processes. There are puzzles with trivial game trees that I have watched players get totally lost in, because the game tree is not apparent in the puzzle manifestation.

If this research addresses this problem, I will be very impressed.

Comment Re:Not a new concept (Score 1) 461

Not going to get into all the arguments here. Yes, it is more complicated in detail than the simple model Walker lays out. But in practice, *if* you count calories as prescribed, *then* the model is good enough.

I'd like to provide an update here. I read about the Hacker's Diet first on Slashdot, in fall 1999. I followed it, and during 2000 I lost 50 pounds. I've kept it off for 13 years now. A few years later I started running. I've now run 96 marathons and ultramarathons, heading towards my 10th consecutive Boston Marathon, I've broken 3 hours four times, and I've run three 100 milers, including Western States. Couldn't be happier with that part of my life.

The running has been a bigger life change than losing weight. But I couldn't have done it, no way, without losing the weight first. And I have the Hacker's Diet to thank for that.

And yes, running 60-70 miles / week, I *still* have to count calories.

Comment Re:Could be a good sign... (Score 5, Informative) 199

I would guess that you've never entered one of these competitions. To do well, it is not sufficient to come up with quick and dirty solutions; these will generally fail. You have to be able to find a good algorithm, quickly, and implement it, catching all the edge cases. These are certainly valuable real-world skills.

Disclaimer -- I was on the Rice team that took 3rd in 1986 (before there were any international teams at all).


Physicists Discover a Way Around Heisenberg's Uncertainty Principle 153

Hugh Pickens writes writes "Science Daily Headlines reports that researchers have applied a recently developed technique to directly measure the polarization states of light overcoming some important challenges of Heisenberg's famous Uncertainty Principle and demonstrating that it is possible to measure key related variables, known as 'conjugate' variables, of a quantum particle or state directly. Such direct measurements of the wave-function had long seemed impossible because of a key tenet of the uncertainty principle — the idea that certain properties of a quantum system could be known only poorly if certain other related properties were known with precision. 'The reason it wasn't thought possible to measure two conjugate variables directly was because measuring one would destroy the wave-function before the other one could be measured,' says co-author Jonathan Leach. The direct measurement technique employs a 'trick' to measure the first property in such a way that the system is not disturbed significantly and information about the second property can still be obtained. This careful measurement relies on the 'weak measurement' of the first property followed by a 'strong measurement' of the second property. First described 25 years ago, weak measurement requires that the coupling between the system and what is used to measure it be, as its name suggests, 'weak,' which means that the system is barely disturbed in the measurement process. The downside of this type of measurement is that a single measurement only provides a small amount of information, and to get an accurate readout, the process has to be repeated multiple times and the average taken. Researchers passed polarized light through two crystals of differing thicknesses: the first, a very thin crystal that 'weakly' measures the horizontal and vertical polarization state; the second, a much thicker crystal that 'strongly' measures the diagonal and anti-diagonal polarization state. As the first measurement was performed weakly, the system is not significantly disturbed, and therefore, information gained from the second measurement was still valid. This process is repeated several times to build up accurate statistics. Putting all of this together gives a full, direct characterization of the polarization states of the light."

Comment It *is* possible to build a reactionless drive... (Score 4, Informative) 419

... sort of. And it is established physics. See Swimming in Spacetime: Motion by Cyclic Changes in Body Shape, Science, 2/27/2003, by Jack Wisdom.

But this mechanism relies on general relativistic effects, and only works in curved spacetime. Momentum conservation is not violated, because while the location of the object changes, its momentum (thus velocity) does not -- it simply cyclicly translates itself through space.

My first thought reading about the EmDrive was that Shaywer had found a way to reproduce this effect using a microwave cavity. But unless I'm mistaken, this does not appear to be the case, and I don't follow the arguments that Shaywer's drive should work.


Fake IPad 2s Made of Clay Sold At Canadian Stores 265

SpuriousLogic writes in with a link to a story about some Canadian consumers who thought they were getting an iPad 2 but instead got the makings of the world's oldest tablets. "As many as 10 fake iPad 2s, all made of slabs of modeling clay, were recently sold at electronic stores in Vancouver, British Columbia. Best Buy and Future Shop have launched investigations into how the scam was pulled off. The tablet computers, like most Apple products, are known for their sleek and simple designs. But there's no mistaking the iPad for one of the world's oldest 'tablet devices.' Still, most electronic products cannot be returned to stores. For the the stores and customers to be fooled by the clay replacements, the thieves must have successfully weighed out the clay portions and resealed the original Apple packaging. Future Shop spokesman Elliott Chun told CTV that individuals bought the iPads with cash, replaced them with the model clay, then returned the packages to the stores. The returned fakes were restocked on the shelve and sold to new, unwitting customers."

Americans Favor Moratorium On New Nuclear Reactors 964

An anonymous reader writes "While a drop in public support for nuclear power would be expected after an incident like the Fukushima reactor crisis, the nuclear disaster in Japan has triggered a much stronger response among Americans. When Japan — the nation that President Obama held up as an example of safe nuclear power being used on a large-scale basis — is unable to effectively control its considerable downside, Americans are understandably leery about the same technology being used even more extensively in this nation. And safety concerns about the existing nuclear plants also deserve serious attention."

Nexus S Beats iPhone 4 In 'Real World' Web Browsing Tests 260

bongey writes "In a series of measured real-world web load tests, the Android-based Nexus S phone spanked the iPhone 4. The Android phone and iPhone 4 median load times were 2.144s and 3.254s respectively. The sample size was 45,000 page loads, across 1000 web sites. It also follows rumors that Apple is intentionally slowing down web apps to make their native apps more favorable."

"The Mets were great in 'sixty eight, The Cards were fine in 'sixty nine, But the Cubs will be heavenly in nineteen and seventy." -- Ernie Banks