Friday Hodgepodge

Friday, March 16, 2018

Four Things

1. If you've ever wondered how they make smart phones water resistant, CNET has you covered:

Speakers and microphones need air to enter and leave your phone, because creating vibrations in the air is how they produce sound. Plus, if a phone is completely airtight, the pressure inside the phone might not be equal to the outside, creating an opportunity for that pressure to breach the phone's seals and let water in.

How do they keep water out? Science! Many manufacturers of water-resistant phones place an incredibly fine mesh in front of their speakers and microphones, prompting the water to follow its natural tendency -- through cohesion and surface tension -- to "stick to itself" rather than passing through. [link omitted]
A related fact I didn't know: Australians customarily use salt water pools. Unfortunately for them, salt water can corrode metal parts in the line of defense, rendering all the other impressive measures moot.

2. Over at Smithsonian Magazine, you can learn how cheese, wheat, and alcohol affected human evolution:
A brown cow, deserving of its reputation as a source of chocolate milk. (Photo by Christian Regg on Unsplash)
Northern Europeans, on the other hand, seem to love their lactose -- 95 percent of them are tolerant, meaning they continue to produce lactase as adults. And those numbers are increasing. "In at least different five cases, populations have tweaked the gene responsible for digesting that sugar so that it remains active in adults," Hawks says, noting it is most common among peoples in Europe, the Middle East and East Africa.

Ancient DNA shows how recent this adult lactose tolerance is, in evolutionary terms. Twenty-thousand years ago, it was non-existent. Today, about one-third of all adults have tolerance. [link omitted]
Later comes interesting speculation as to why celiac disease seems not to have been selected against during that same time span.

3. A lengthy piece at BuzzFeed reminds me somewhat of the story I encounter now and again, about Abraham Lincoln's many failures:
"Couldn't hold a job" is no exaggeration. After being fired from another gig at the Illinois Central Railroad for getting into a fight, he became an Arkansas lawyer in 1915 -- when you could practice in the Justice of the Peace Court without being admitted to the bar -- but ended that career by getting "into a fistfight with his own client in court and directly in front of a judge," as [Josh] Ozersky described it in his book. He was arrested, charged with battery, and barred from further practice.

Then, he was fired from a job selling insurance.
This man's story, too, is inspiring, but you'll have to follow the link to find out who it is. I'd previously learned of his rough childhood, but this piece focuses on the ... circuitous ... route to success he took as an adult.

4. How much sunlight would you get at high noon on Pluto? NASA has a site (via John D. Cook) that will calculate your "Pluto Time."
Pluto orbits on the fringes of our solar system, billions of miles away. Sunlight is much weaker there than it is here on Earth, yet it isn't completely dark. In fact, for just a moment near dawn and dusk each day, the illumination on Earth matches that of high noon on Pluto.

We call this Pluto Time. If you go outside at this time on a clear day, the world around you will be as bright as the brightest part of the day on Pluto.
I'm still waiting on a clear day to try this.

-- CAV


Dinwar said...

Saltwater pools are extremely common in the Southeastern USA as well--they are lower-maintenance in this hot, humid environment. I will definitely want to share this with my friends down here! Thanks!

Gus Van Horn said...

Glad to help.