Category Archives: STEM

Science, Technology, Engineering, and Mathematics

Survivorship Bias

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Taking survivorship bias into account, Wald went ahead and worked out how much damage each individual part of an airplane could take before it was destroyed – engine, ailerons, pilot, stabilizers, etc. – and then through a tangle of complicated equations he showed the commanders how likely it was that the average plane would get shot in those places in any given bombing run depending on the amount of resistance it faced. Those calculations are still in use today.

via Survivorship Bias « You Are Not So Smart.

Simply put, survivorship bias is your tendency to focus on survivors instead of whatever you would call a non-survivor depending on the situation. Sometimes that means you tend to focus on the living instead of the dead, or on winners instead of losers, or on successes instead of failures. In Wald’s problem, the military focused on the planes that made it home and almost made a terrible decision because they ignored the ones that got shot down.

Scientists growing new crystals to make LED lights useful for office, home

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Technically the LEDs produce light by passing electrons through a semiconductor material, in combination with materials called phosphors that glow when excited by radiation from the LED. “But it’s hard to get one phosphor that makes the broad range of colors needed to replicate the sun,” said John Budai, a scientist in ORNL’s Materials Science and Technology division in a release. “One approach to generating warm-white light is to hit a mixture of phosphors with ultraviolet radiation from an LED to stimulate many colors needed for white light.”

via Scientists growing new crystals to make LED lights useful for office, home.

3-D Printing Will Soon Become a Routine Manufacturing Tool

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Additive manufacturing—the industrial version of 3-D printing—is already used to make some niche items, such as medical implants, and to produce plastic prototypes for engineers and designers. But the decision to mass-produce a critical metal-alloy part to be used in thousands of jet engines is a significant milestone for the technology. And while 3-D printing for consumers and small entrepreneurs has received a great deal of publicity, it is in manufacturing where the technology could have its most significant commercial impact

via 3-D Printing Will Soon Become a Routine Manufacturing Tool | MIT Technology Review.

If It Ain’t Broke, Don’t Fix It: Ancient Computers in Use Today

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Sparkler Filters of Conroe, Texas, prides itself on being a leader in the world of chemical process filtration. If you buy an automatic nutsche filter from them, though, they’ll enter your transaction on a “computer” that dates from 1948.

via If It Ain’t Broke, Don’t Fix It: Ancient Computers in Use Today | PCWorld.

The key punch isn’t the only massive accessory in Sparkler’s arsenal. The 402 also links to an IBM 514 Reproducing Punch, which has been broken for three years. When it works properly, the 514 spits out punched “summary cards,” which typically contain the output of the 402’s operation (such as sum totals) for later reuse. Sparkler stores all of its punched data cards–thousands and thousands of them–in stacks of boxes.

Intel’s Haswell Takes A Major Step Forward; Integrates Voltage Regulator

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Haswell incorporates a refined VRM on-die that allows for multiple voltage rails and controls voltage for the CPU, on-die GPU, system I/O, integrated memory controller, as well as several other functions. Intel refers to this as a FIVR (Fully Integrated Voltage Regulator), and it apparently eliminates voltage ripple and is significantly more efficient than your traditional motherboard VRM. Added bonus? It’s 1/50th the size.

via Intel’s Haswell Takes A Major Step Forward; Integrates Voltage Regulator – HotHardware.

The British ‘Atlantis’ is mapped in detail

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The camera uses high frequency sound and acoustic lenses to refract sound waves and create film footage without light. The technology is usually reserved for creating a fly-by of sunken ships, but it has now picked up the wreckage of the former trading hub in astonishing detail. In addition, old naval navigation charts helped in the tracking and mapping of where the former coastline stood.

via The British ‘Atlantis’ is mapped in detail | Ars Technica.

Meanwhile in Brazil, the discovery of a large lump of granite rock 1,500km (932 miles) off the coast of Rio de Janeiro has led to claims that the real Atlantis has been discovered.

NASA’s system for avoiding collisions with space junk

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Potential collisions are flagged for monitoring if there’s simply a high probability of conjunction. Typically, the probability goes down after a couple of additional days of tracking, but in rare cases this doesn’t happen (and, in a few, the probability went up with further monitoring). When the probability doesn’t go down, the software can calculate a maneuver that will reduce the probability of collision to an acceptable level. The solution will take into account other potential hazards as well as mission requirements—some Earth-monitoring satellites can’t orbit above a certain altitude and still perform their jobs.

via Saving Fermi: NASA’s system for avoiding collisions with space junk | Ars Technica.

Reasons to believe

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It’s time to assume the mantle of Defender of the Faith. I’m going to give you ten arguments for believing P!=NP: arguments that are pretty much obvious to those who have thought seriously about the question, but that (with few exceptions) seem never to be laid out explicitly for those who haven’t. You’re welcome to believe P=NP if you choose. My job is to make you understand the conceptual price you have to pay for that belief.

via Shtetl-Optimized » Blog Archive » Reasons to believe.