April 22, 2016 -- A Quick Run Around the Web

Self-Defense:

• First up, Active Response Training's Weekend Knowledge Dump. A whole slew of interesting articles.
• "Deep Concealment Options for the 'Non-Permissive Environment'"--Active Response Training. Greg Ellifritz describes how he carried weapons past security at venues in jurisdictions where it was legal to carry, but the property owners (or event operators) prohibited carrying of weapons. Although the author of The Captain's Journal could not understand how this could be "legal," it is an issue of semantics. Many jurisdictions do not have laws making it criminal trespass merely to enter onto private property with a concealed weapon when the owner has posted a "no weapons" sign--in such jurisdictions, it may be "illegal" in the sense of being a tort, but not constitute a crime. 
• "The Complete Guide to Bolt Manipulation, Part 1: Fundamental Principles"--Art of the Rifle.
• "The Complete Guide to Bolt Manipulation, Part 2: Specific Theory"--Art of the Rifle.
• "The Complete Guide to Bolt Manipulation, Part 3: Technique"--Art of the Rifle.
• "The Complete Guide to Bolt Manipulation, Part 4: Delving into Finer Points"--Art of the Rifle.
• "The Complete Guide to Bolt Manipulation, Part 5: Advice and Practice Tips"--Art of the Rifle.
• "The Complete Guide to Bolt Manipulation, Part 6: Avoiding Problems and Pitfalls"--Art of the Rifle.
• "Butterflies and Standing Hair"--Schafer's Self-Defense Corner. The physiology of why we get "butterflies in our stomach" or our hair may "stand on end."
• "Handgun Selection"--S.P. Wenger's Defensive Use of Firearms. Much better and more thorough than the run-of-the-mill articles I generally come across on this topic.

Other Stuff:

• "Think You Can Drive Fast Enough to Escape an Erupting Volcano?"--Wired. From the article:

... If the Silver Creek Caldera erupted for 2.5 to 10 hours at a sustained rate of 38 to 150 million cubic meters per second, then these flows could move blocks even moving at only a few tens of kilometers per hour. Now, that eruption rate is huge, tens to hundreds of times more than Pinatubo, Tambora or Novarupta, some of the biggest eruptions of the last few centuries.

This means that the eruption of the Peach Springs Tuff was at least as large if not larger than the super-eruptions like Toba or Taupo. Yet, if you were 150 kilometers from the eruption, you might have upwards of 10 hours to get out of harm’s way (well, at least out of the way of the massive pyroclastic flows—the resulting ash fall and climate cooling is a little trickier to handle).

• "Public Utility Companies Stockpile Equipment For Possible Apocalyptic Disaster"--Daily Caller. "Utility companies such as American Electric Power Co. and Exelon Corp. are helping fund the creation of a Delaware company called Grid Assurance LLC, which will be used to store massive power transformers and circuit breakers in unidentified places throughout the country."
• "No One Works in 1 in 5 U.S. Families"--The Washington Free Beacon.

• Related: "Capitalism and the Minimum Wage: 'I Got Mine, Screw You.'"--Fred On Everything. "An economic system that works reasonably well when there are lots of simple jobs doesn’t when there aren’t. In particular, the large number of people at IQ 90 and below will increasingly be simply unnecessary."

• "Where are America’s Drowned Cities?"--Robert Zubrin at The American Thinker. The globe has been warming for the past 400 years, yet there is no evidence of rising sea levels.
• "In proof we trust: Blockchain technology will revolutionise far more than money: it will change your life. Here’s how it actually works"--Aeon Magazine. A taste:

If a company or a government department were in charge of the record, it would be vulnerable – if the company went bust or the government department shut down, for example. But with a distributed record there is no single point of vulnerability. It is decentralised. At times, some computers might go awry, but that doesn’t matter. The copies on all the other computers and their unanimous approval for new information to be added will mean the record itself is safe.

This is possibly the most significant and detailed record in all history, an open-source structure of permanent memory, which grows organically. It is known as the blockchain. It is the breakthrough tech behind the digital cash system, Bitcoin, but its impact will soon be far wider than just alternative money.

• "The Curious Link Between the Fly-By Anomaly and the 'Impossible' EmDrive Thruster"--MIT Technology Review. A new theory may explain both: 

McCulloch’s idea is that inertia arises from an effect predicted by general relativity called Unruh radiation. This is the notion that an accelerating object experiences black body radiation. In other words, the universe warms up when you accelerate.

According to McCulloch, inertia is simply the pressure the Unruh radiation exerts on an accelerating body.

That’s hard to test at the accelerations we normally observe on Earth. But things get interesting when the accelerations involved are smaller and the wavelength of Unruh radiation gets larger.

At very small accelerations, the wavelengths become so large they can no longer fit in the observable universe. When this happens, inertia can take only certain whole-wavelength values and so jumps from one value to the next. In other words, inertia must quantized at small accelerations.

McCulloch says there is observational evidence for this in the form of the famous fly by anomalies. These are the strange jumps in momentum observed in some spacecraft as they fly past Earth toward other planets. That’s exactly what his theory predicts.

Testing this effect more carefully on Earth is hard because the accelerations involved are so small. But one way to make it easier would be to reduce the size of allowed wavelengths of Unruh radiation. “This is what the EmDrive may be doing,” says McCulloch.

The idea is that if photons have an inertial mass, they must experience inertia when they reflect. But the Unruh radiation in this case is tiny. So small in fact that it can interact with its immediate environment. In the case of the EmDrive, this is the truncated cone.

The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust.