Scientists Power a Toy Car Using Evaporation

Scientists have long known how to use precipitation as a source of renewable energy. Now, it seems as though a team of researchers at Columbia University has figured out how to harness evaporation, too. 

Xi Chen and his colleagues noticed that spores of the bacterium Bacillus subtilis expand when they’re exposed to humidity and contract when they’re dry, behaving much like a muscle. When lined up on a piece of tape, the expanding and contracting spores were able to straighten and curl the strips of tape as the humidity of their environment changed. Their research is detailed in a paper published in the journal Nature Communications.

This discovery suggests that evaporation may be eventually be used as a source of power. During the study, the team observed that two strips of spores could make the tape scrunch, instead of curl, and several of them acting together could contract with enough force to lift small weights of 0.2 lbs to 0.7 lbs. This may not seem like much, but is in fact 50 times the weight of the strips themselves. They wondered if harnessing the collective force of these contractions could propel a device.

They tested that idea by building an "engine." The researchers stretched these so-called HYDRA strips horizontally over a small container of water covered with shutters. As the water evaporated, the strips expanded, causing the shutters to open. Once the water had been released, the humidity dropped, the spores contracted, and the shutters closed, allowing the process to begin again. By collecting, storing, and releasing the evaporation in a controlled, cyclic fashion, the researchers created a continuous power source. 

Chen and his team built another generator, resembling a spore Ferris wheel, which they dubbed the "Moisture Mill." They placed half of the wheel in a moist environment, and the other half in a less-humid space. The tiny imbalance created by the expansion of the spores in the humid environment caused the wheel to continuously tip forward, creating a rotation. This wheel was then affixed to a tiny toy car—thus creating the first evaporation-powered vehicle.

The possibilities for this newfound source of energy have yet to be fully explored, but researchers speculate that evaporation could someday be put to work in batteries, smart sportswear, and robotic limbs.

[h/t Discover]

Afternoon Map
The Most Searched Shows on Netflix in 2017, By State

Orange is the New Black is the new black, at least as far as Netflix viewers are concerned. The women-in-prison dramedy may have premiered in 2013, but it’s still got viewers hooked. Just as they did in 2017, took a deep dive into Netflix analytics using Google Trends to find out which shows people in each state were searching Netflix for throughout the year. While there was a little bit of crossover between 2016 and 2017, new series like American Vandal and Mindhunter gave viewers a host of new content. But that didn’t stop Orange is the New Black from dominating the map; it was the most searched show in 15 states.

Coming in at a faraway second place was American Vandal, a new true crime satire that captured the attention of five states (Illinois, Kansas, Massachusetts, Minnesota, and Wisconsin). Even more impressive is the fact that the series premiered in mid-September, meaning that it found a large and rabid audience in a very short amount of time.

Folks in Alaska, Colorado, and Oregon were all destined to be disappointed; Star Trek: Discovery was the most searched-for series in each of these states, but it’s not yet available on Netflix in America (you’ve got to get CBS All Access for that, folks). Fourteen states broke the mold a bit with shows that were unique to their state only; this included Big Mouth in Delaware, The Keepers in Maryland, The OA in Pennsylvania, GLOW in Rhode Island, and Black Mirror in Hawaii.

Check out the map above to see if your favorite Netflix binge-watch matches up with your neighbors'. For more detailed findings, visit

Afternoon Map
Monthly Internet Costs in Every Country

Thanks to the internet, people around the world can conduct global research, trade tips, and find faraway friends without ever leaving their couch. Not everyone pays the same price for these digital privileges, though, according to new data visualizations spotted by Thrillist.

To compare internet user prices in each country, cost information site created a series of maps. The data comes courtesy of English market research consultancy BDRC and, which teamed up to analyze 3351 broadband packages in 196 nations between August 18, 2017 and October 12, 2017.

In the U.S., for example, the average cost for internet service is $66 per month. That’s substantially more than what browsers pay in neighboring Mexico ($27) and Canada ($55). Still, we don’t have it bad compared to either Namibia or Burkina Faso, where users shell out a staggering $464 and $924, respectively, for monthly broadband access. In fact, internet in the U.S. is far cheaper than what residents in 113 countries pay, including those in Saudi Arabia ($84), Indonesia ($72), and Greenland ($84).

On average, internet costs in Asia and Russia tend to be among the lowest, while access is prohibitively expensive in sub-Saharan Africa and in certain parts of Oceania. As for the world’s cheapest internet, you’ll find it in Ukraine and Iran.

Check out the maps below for more broadband insights, or view’s full findings here.

Map of Internet costs in each country created by information site

Map of Internet costs in each country created by information site

Map of Internet costs in each country created by information site

Map of Internet costs in each country created by information site

Map of Internet costs in each country created by information site

[h/t Thrillist]


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