Don't Forget the Gin

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Recipe For Safer Drinking Water? Add Sun, Salt And Lime

“So basically you add dirt and salt, to make the water cleaner?” I asked him.

“Right,” said Pierce laughing, “It’s not exactly intuitive.”

Perhaps not so intuitive to the average person, but it’s a process that may be more familiar to makers of wine, where bentonite is commonly used to clarify wine of impurities.
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Schwab and medical student Alexander Harding discovered that adding a half a Persian lime to a two-liter bottle of water reduced the disinfection time in the sun from six hours to a half an hour. That’s just about the same amount of time it takes to boil water, and much more energy efficient.

The Essential Parts are Not Too Complicated, and the Principle is Easily Explained

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A film produced by the NPL Film Unit in the 1950s explaining the principles behind the first accurate atomic clock, designed by Louis Essen and built at the National Physical Laboratory in 1955.

I notice they were talking about achieving good vacuum while showing someone handling a vacuum component with their bare hands, which you wouldn’t normally do — fingerprints outgas. But it was the oven, so all of that junk gets baked off pretty quickly.

The mention a performance of a ten-thousandth of a million, or a part in 10^10. Clocks/frequency standards in use today (i.e. part of time scales, reporting their values) do ~100,000 times better, and experimental ones do even better than that, albeit for relatively short durations.

That device, which is a “physics package” (all the fun stuff) plus 6 equipment racks, now fits into about 6″ of space in a single equipment rack … and the devices are orders of magnitude better.

via BoingBoing

Magnetic Putty? That's Silly!

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DIY Magnetic Putty

By adding a ferrous component to an already wacky toy we can keep all characteristics of the original putty, but now have the additional dimension of magnetism! I’ve seen magnetic thinking putty for sale on other websites, but I’ll show you how you can make your own for a fraction of the price and in about 20 minutes.

No Use Crying Over This, Either

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The Physics of Spilled Coffee

“I cannot say for sure if coffee spilling has been detrimental to scientific research to any significant extent,” says study author Rouslan Krechetnikov, a mechanical engineer at the University of California, Santa Barbara. “But it can certainly be disruptive for a train of thought.”

Krechetnikov and his graduate student Hans Mayer decided to investigate coffee spilling at a fluid dynamics conference last year when they watched overburdened participants trying to carry their drinks to and fro. They quickly realized that the physics wasn’t simple. Aside from the mechanics of human walking, which depends on a person’s age, health, and gender, there is the highly involved science of liquid sloshing, which depends on a complex interplay of accelerations, torques, and forces.

I have a vague recollection of this being studied years ago, looking at walking resonances.

However, physicist Andrzej Herczynski at Boston College thinks Krechetnikov and Mayer’s study didn’t go far enough. “I was personally a bit disappointed that the study is limited to cylindrical mugs … leaving out the very common curved or conical cups, such as those used for cappuccinos and lattes in Italy,” he says. “Still, the paper seems at minimum destined for the Ig Nobel Prize.”

The conical spill-resistant mugs were popular with my seagoing shipmates back in the day.

You Had Me at "Waffle-Iron Brownies"

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Common Appliances, Uncommon Uses

Imagine our delight at seeing a soufflé rise up in the slow cooker, a frozen mixed drink take shape in the ice cream maker. Our late-night snack cravings found succor with a waffle iron. And if you don’t have these appliances, or don’t understand why anyone would veer from the standard, there are conventional instructions for most of the recipes too.

Not sure I agree with the criterion that it has to be faster than the conventional way; if it’s better or somehow more convenient but takes longer (e.g. a novel use for a crock-pot), then I would have included it.

Doctor Obvious Meets Abbie Normal

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Put Away The Bell Curve: Most Of Us Aren’t ‘Average’

For decades, teachers, managers and parents have assumed that the performance of students and employees fits what’s known as the bell curve — in most activities, we expect a few people to be very good, a few people to be very bad and most people to be average.

This isn’t the first time I’ve found that someone is shocked, shocked to find that you have non-normal distributions after you’ve run your sample through some kind of discriminator. Managers don’t tend to hire the unqualified. Students that aren’t college material tend not to go to college, or drop out. If you aren’t good enough to be competitive at a sport you won’t be on the team. Once you have limited your sample in a way that introduces a bias, don’t automatically expect the distribution to be normal.

Nobody Saw This Coming

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How the Blind Are Reinventing the iPhone

For the visually impaired community, the introduction of the iPhone in 2007 seemed at first like a disaster — the standard-bearer of a new generation of smartphones was based on touch screens that had no physical differentiation. It was a flat piece of glass. But soon enough, word started to spread: The iPhone came with a built-in accessibility feature. Still, members of the community were hesitant.

But no more. For its fans and advocates in the visually-impaired community, the iPhone has turned out to be one of the most revolutionary developments since the invention of Braille. That the iPhone and its world of apps have transformed the lives of its visually impaired users may seem counter-intuitive — but their impact is striking.