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Comment Re:Math (Score 1) 229

by RockGrumbler (#53796923) Attached to: 'To Live Your Best Life, Do Mathematics'
I have a math minor and work in software. It's not particularly useful in my day to day job, but it is a useful tool when I indulge my curiosity about other things. I built a 3D game engine once, and I had a basic knowledge in vector / math. I used that to go and learn further, the base made it feasible.

Comment They are not using StringBuffer or StringBuilder (Score 1) 486

by RockGrumbler (#49336431) Attached to: No, It's Not Always Quicker To Do Things In Memory
One of the first optimizations you learn when writing Java in a moderate load environment is to use StringBuffer or StringBuilder when concatenating Strings. There is probably a similar construct in Python. The test was not written from a place of experience or was purposely constructed this way to prove their pre assumed point.
Programming

No, It's Not Always Quicker To Do Things In Memory 486

Posted by Soulskill from the performance-that-fails-to-perform dept.
itwbennett writes: It's a commonly held belief among software developers that avoiding disk access in favor of doing as much work as possible in-memory will results in shorter runtimes. To test this assumption, researchers from the University of Calgary and the University of British Columbia compared the efficiency of alternative ways to create a 1MB string and write it to disk. The results consistently found that doing most of the work in-memory to minimize disk access was significantly slower than just writing out to disk repeatedly (PDF).
Math

Mathematicians Use Mossberg 500 Pump-Action Shotgun To Calculate Pi 311

Posted by samzenpus from the less-common-core-math dept.
KentuckyFC (1144503) writes "Imagine the following scenario. The end of civilization has occurred, zombies have taken over the Earth and all access to modern technology has ended. The few survivors suddenly need to know the value of pi and, being a mathematician, they turn to you. What do you do? According to a couple of Canadian mathematicians, the answer is to repeatedly fire a Mossberg 500 pump action shotgun at a square aluminum target about 20 meters away. Then imagine that the square is inscribed with an arc drawn between opposite corners that maps out a quarter circle. If the sides of the square are equal to 1, then the area of the quarter circle is pi/4. Next, count the number of pellet holes that fall inside the area of the quarter circle as well as the total number of holes. The ratio between these is an estimate of the ratio between the area of the quarter circle and the area of a square, or in other words pi/4. So multiplying this number by 4 will give you an estimate of pi. That's a process known as a Monte Carlo approximation and it is complicated by factors such as the distribution of the pellets not being random. But the mathematicians show how to handle these too. The result? According to this method, pi is 3.13, which is just 0.33 per cent off the true value. Handy if you find yourself in a post-apocalyptic world."
Space

Scientists Forced To Reexamine Theories In Light of Massive Gamma-Ray Burst 128

Posted by Soulskill from the turns-out-we-were-wrongish dept.
cold fjord writes "Earlier this year we discussed news of a shockingly powerful gamma-ray burst. Scientists have had time to study the phenomenon, but it's not offering up any easy answers. The Christian Science Monitor reports, 'An exploded star some 3.8 billion light-years away is forcing scientists to overhaul much of what they thought they knew about gamma-ray bursts – intense blasts of radiation triggered, in this case, by a star tens of times more massive than the sun that exhausted its nuclear fuel, exploded, then collapsed to form a black hole. Last April, gamma rays from the blast struck detectors in gamma-ray observatories orbiting Earth, triggering a frenzy of space- and ground-based observations. Many of them fly in the face of explanations researchers have developed during the past 30 years ... "Some of our theories are just going down the drain," said Charles Dermer, an astrophysicist at the Los Alamos National Laboratory in New Mexico ... while typical long-duration bursts last from a few seconds to a few minutes, GRB 130427A put on its display for 20 hours. ... [W]ith GRB 130427A, some of the highest energy photons, including the new record-holder, appeared hours after the blast. "This is hard to explain with our current models," Dermer said. In addition, gamma rays and emissions at visible wavelengths brightened and dimmed in tandem, quite unexpected because theory suggested they come from different regions of the expanding shells of material and thus should have peaked and dimmed at different times. Finally, theorists had posited different mechanisms for generating gamma rays and X-rays that are part of the light show a long-duration gamma-ray burst puts on. The result should have been a fadeout for the two forms of light punctuated by periods where emissions were interrupted. Instead, the two dimmed smoothly. The theoretical edifice GRB 130427A is eroding has been 46 years in the making.' — The 21 November 2013 Science Express has abstracts for four related papers (first, second, third, fourth). More at Sky & Telescope and NASA."

Comment Demon under the microscope (Score 1) 453

by RockGrumbler (#45491399) Attached to: Imagining the Post-Antibiotic Future
The book "Demon under the microscope" looks at the creation and popularization of the first widely used antibiotic, sulfa. It does a good job of describing all the horrible problems society was dealing with before sulfa came about. It's pretty scary to imagine a scenario where antibiotics don't work anymore.
News

Interview: John McAfee Answers Your Questions 239

Posted by samzenpus from the read-all-about-it dept.
Last week you had the chance to ask software designer and international man on the run John McAfee about his exploits in business, programming, and the jungle. Mr. McAfee provided some extraordinarily entertaining and frank answers to your questions. Read below and enjoy.
Electronic Frontier Foundation

DOJ Often Used Cell Tower Impersonating Devices Without Explicit Warrants 146

Posted by Unknown Lamer from the bending-the-rules dept.
Via the EFF comes news that, during a case involving the use of a Stingray device, the DOJ revealed that it was standard practice to use the devices without explicitly requesting permission in warrants. "When Rigmaiden filed a motion to suppress the Stingray evidence as a warrantless search in violation of the Fourth Amendment, the government responded that this order was a search warrant that authorized the government to use the Stingray. Together with the ACLU of Northern California and the ACLU, we filed an amicus brief in support of Rigmaiden, noting that this 'order' wasn't a search warrant because it was directed towards Verizon, made no mention of an IMSI catcher or Stingray and didn't authorize the government — rather than Verizon — to do anything. Plus to the extent it captured loads of information from other people not suspected of criminal activity it was a 'general warrant,' the precise evil the Fourth Amendment was designed to prevent. ... The emails make clear that U.S. Attorneys in the Northern California were using Stingrays but not informing magistrates of what exactly they were doing. And once the judges got wind of what was actually going on, they were none too pleased:"

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"Unibus timeout fatal trap program lost sorry" - An error message printed by DEC's RSTS operating system for the PDP-11

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