## The physics of fidget spinners

Wired's Rhett Allain built a rig with a laser and light sensor to study fidget spinner physics and determine how long it will spin based on the starting angular velocity. Allain's article will make a great teachable moment for my kids, as in I'll ask them to read it and explain it to me. From Wired:

If I know the starting angular speed and I assume a final angular speed of zero radians per second, I can calculate the spin time:

All I need is the angular acceleration—assuming it remains constant as the spinner slows. I could calculate the angular acceleration based on the change in angular velocity, but this isn’t so simple to measure. The spinner moves too quickly to get a good video of its motion, so I will use a laser in a rig I built to measure the change in the angular velocity.

Basically, the laser shines down onto a light sensor. As the spinner spins, it occasionally blocks the sensor, interrupting the laser. By measuring the values from the light sensor, I determine the spin rate. But this creates a couple of problems. First, the light change rate and the rotation rate differ because the three “lobes” in the spinner create multiple openings during each rotation. Second, the spinner will spin for a significant amount of time such that it would be difficult to analyze it all at once...

Now for the fun trick. Instead of looking at a giant plot of light vs. time (the full data is over 2 minutes), I will plot the Fourier transform of this data.

## Entrancing avant-garde music video generated by algorithm

Damien Henry, co-inventor of Google Cardboard, trained a machine learning algorithm using footage shot from a moving vehicle and then had the machine generate this beautiful video.

"Graphics are 100% generated by an algorithm in one shot. No edit or post-processing," Henry writes. "Except the first one, all frames are calculated one by one by a prediction algorithm that tries to predict the next frame from the previous one."

The soundtrack is the Steve Reich masterpiece "Music for 18 Musicians."

## Remember ebola? Media-inflamed health scares, quantified

Just how overblown was the media panic over ebola? This interactive chart compares media coverage of a dozen health scares, from mad cow disease to zika. Read the rest

## Mushrooms may help in the fight against bee colony collapse

It's mushrooms to the rescue in a major study to stop bee colony collapse disorder. One culprit, parasitic varroa mites, stood out as a major threat because they were developing tolerance for many pesticides. Read the rest

## Swearing associated with honesty, say scientists

Impoliteness and vulgarity are, according to recent recearch, a sign of honesty. Moreover, "the more an individual swears, the more honest they are likely to be."

They first asked a group of 276 participants about their swearing habits, as well as how honest they were in different situations, and found the most honest people were also the heaviest swearers.

They also found that people were much more likely to use swearing as a way to express themselves and their emotions, rather than in an anti-social or harmful way towards others.

In a second study the researchers tested these findings in a more real-life setting, by analysing the status updates of more than 73,000 Facebook users.

They measured for honesty (previous research shows liars prefer to use third-person pronouns than first-person ones and more negative words) and profanity.

Again, they found that honest people were more likely to use profane language.

They ranked swearing and integrity by U.S. state. The sweariest state, Connecticut (52%), was also the second-most most honest (86%). Polite Utah (26%) scored a relatively untrustworthy 65%.

Most-honest Iowa (87%), though, could only maintain a middling swear rate of 40%. Still, the habitual liars of Georgia (49% integrity) sure talk sweet (36% swears). Read the rest

## Horrifying footage of a hippo, nature's top human-killer, savaging woman in shallow water

Nature, red in toot and boop.

Here's more video of this terrifying monster:

## Why people don't return shopping carts

Why do so many people just leave their shopping carts in the parking lot after unloading groceries instead of rolling them to the receptacles? Sure, one answer is laziness. But it's actually more interesting than that, involving what kind of cart user you are and how your motivation aligns with two general categories of social norms. You may be someone who always returns the cart, never returns it, only does so if it's convenience, feels pressure to return it from either a cart attendant or someone waiting to park in the spot where your cart is parked, you have children and they get a kick out of returning it. From Krystal D'Costa's "Anthropology in Practice" column in Scientific American:

Social norms fall into two general categories. There are injunctive norms, which drive our responses based on our perception of how others will interpret our actions. This means that we're inclined to act in certain ways if we think people will think well or think poorly of us. And there are descriptive norms, where our responses are driven by contextual clues. This means we're apt to mimic behaviors of others—so what we see or hear or smell suggests the appropriate/accepted response or behavior that we should display.

Supermarkets can try and guide our behavior with receptacles or cart attendants, but they’re competing with our own self-serving goals, which in this case may be staying dry, keeping an eye on our children, or simply getting home as quickly as possible, and we’re being guided by the ways others behave on top of that.

## Watch a crushed Life Saver emit light at 28,000 frames per second

Destin from Smarter Every Day just polted a cool video on his alt channel: a demonstration of triboluminescence that occurs when a Wint-O-Green Life Saver candy is crushed. Read the rest

## Why the NYT hired a science denier

The New York Times' new columnist, Bret Stephens, is an everyday conservative: he thinks institutional racism is imaginary, that campus rape is a big lie, and that the "Arab Mind" is "diseased". But these are just opinions, and common ones on the right. It is his anti-science positions, on display in his first fact-mangled column about climate change, that has galvanized disgust.

Much has been said about him, but it is the Times itself that has committed a "jaw-dropping error" and whose warped motives promise that it will be repeated.

Ryan Cooper in The Week directs particular ire at the Times' claim about wanting a diversity of voices, where the agreement of millions is enough to justify a hire. This allows so many possibilities that it betrays the excuse.

If the Times were really committed to ideological diversity in its op-ed page, it would at a minimum hire a conservative who actually supports President Trump, and perhaps even more importantly hire someone with Bernie Sanders-style politics. (Sanders is the most popular politician in the country, yet there are more supporters of torture among columnists of our two major national newspapers than supporters of the senator.)

What we see here is that the neurotic upper-class liberal need for civil debate over important issues stops the moment we reach territory they actually care about. ... A rich, glib, dumb, anti-Trump conservative, on the other hand, can give Upper East Side cocktail parties that frisson of intellectual disputation while conveniently avoiding most of the actually important questions.

## The true color of Saturn's north pole is a stunning blue

Astroparticle physicist Sophia Nasr posted a gorgeous photo of Saturn's north pole, processed to account for a luminance layer. Instead of a reddish hue, it is a breathtaking cerulean blue. Jason Major replicated the results. Read the rest

## New camera shoots at 5 trillion frames per second

Reserachers at Lund Univeristy in Sweden have developed a camera that captures images at a rate equivalent to 5 trillion frames per second, quintupling the previous high mark. Read the rest

## Simple interactive Periodic Table on the web

Periodic Stats is a dead-easy web-based Periodic Table to click around, showing all the stats and the history of each element. The only thing missing are illustrations of each one! [via Reddit] Read the rest

## This working RC plane has KFC buckets for wings

To demonstrate the Magnus effect, YouTuber PeterSripol grabbed a couple of KFC buckets and tricked out an RC plane. The resulting trial and error is mostly the latter. Read the rest

## Antarctica's Blood Falls mapped and analyzed a century after discovery

One of the weirdest places in Antarctica is Blood Falls, a five-story cascade of blood-red liquid pouring from Taylor Glacier. Researchers finally traced its source: a saltwater lake millions of years old trapped under the glacier.

## Video of a lamb fetus in an artificial womb

Fetal lambs survived for weeks in an experimental artificial womb, and scientists hope that the breakthrough could lead to new treatments for premature babies and perhaps the dreamed-of machine utopia where humans are kept mindlessly writhing in translucent plastic sheaths filled with psuedoamniotic liquid.

Physicians at the Children’s Hospital of Philadelphia placed fetal lambs into the transparent bags and connected their umbilical cords to a machine that oxygenated their blood. The lambs own hearts provided the pumping power.

Eight lambs survived for as long as four weeks inside the devices. The gestational age of the animals was equivalent to a human fetus of 22 or 23 weeks, about the earliest a human baby can be born and expected to survive outside the womb. A full-term baby is born at 40 weeks.