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10 Things You Might Not Know About Daylight Saving Time

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Most parts of the country will be losing an hour this weekend (or "springing forward," if your glass is half-full) when clocks are reset for Daylight Saving Time. And while this means some appreciated extra sunlight in the evenings, early risers (or those who savor sleeping in on the weekends) are likely already dreading Sunday morning. Here are 10 things you should know before making the biannual change.

1. BENJAMIN FRANKLIN WAS HALF JOKING WHEN HE SUGGESTED IT.

More than a century before Daylight Saving Time (DST) was adopted by any major country, Benjamin Franklin proposed a similar concept in a satirical essay. In a piece called "An Economical Project for Diminishing the Cost of Light," published in The Journal of Paris in 1784, he argued:

All the difficulty will be in the first two or three days; after which the reformation will be as natural and easy as the present irregularity [...] Oblige a man to rise at four in the morning, and it is more than probable he will go willingly to bed at eight in the evening; and, having had eight hours sleep, he will rise more willingly at four in the morning following.

In one prophetic passage, he pitched the idea as a money-saver (though at the time people would have been conserving candle wax rather than electricity). To enforce the out-there plan, Franklin suggested taxing shutters, rationing candles, banning non-emergency coach travel after dark, and firing cannons at sunrise to rouse late-sleepers. While his essay clearly brought up some practical points, Franklin may have originally written it as an excuse to poke fun at the French for being lazy. He wrote that the amount of sunlight that goes wasted each morning would likely come as a shock to readers who "have never seen any signs of sunshine before noon."

2. OFFICIAL CREDIT FOR THE IDEA GOES TO A BUG COLLECTOR.

The first serious case for DST came from a peculiar place. While working at a post office by day, an entomologist named George Vernon Hudson, who did most of his bug hunting at night, soon became frustrated by how early the sun set during the summer months. He reasoned that springing the clocks forward would allow more daylight for bug collecting—along with other evening activities. The clocks could be switched back in the winter when people (and bugs) were less likely to be found outdoors.

When the idea was proposed to a scientific society in New Zealand in 1895 it was panned for being pointless and overly complicated. Just two decades later, Daylight Saving Time would begin its spread across the developed world.

3. WWI PUSHED DAYLIGHT SAVING INTO LAW.

In 1916, Germany became the first country to officially adopt Daylight Saving Time. It was born out of an effort to conserve coal during World War I, and Britain, along with many other European nations, was quick to follow the Germans’ lead. It wasn’t until 1918 that the time change spread to the U.S. A year after entering the war, America began practicing DST as an electricity-saving measure. Most countries, including the U.S., ceased nationwide observation of the switch following wartime. Until, that is …

4. IT GAINED RENEWED POPULARITY DURING THE ENERGY CRISIS.

Although it was already being practiced in many states, the U.S. reconsidered nationwide DST in the 1970s, when, once again, the argument pivoted back to energy conservation. The oil embargo of 1973 had kicked off a nationwide energy crisis and the government was looking for ways to reduce public consumption. Year-round Daylight Saving Time was imposed in the beginning of 1974 to save energy in the winter months. Not everyone was enthusiastic about the change: Some of the harshest critics were parents suddenly forced to send their children to school before sunrise.

5. IT MAY ACTUALLY BE AN ENERGY WASTER.

Despite Daylight Saving Time’s origins as an energy saving strategy, research suggests it might actually be hurting the cause. One 2008 study conducted in Indiana found that the statewide implementation of DST two years earlier had boosted overall energy consumption by one percent. While it’s true that changing the clocks can save residents money on lighting, the cost of heating and air conditioning tends to go up. That extra hour of daylight is only beneficial when people are willing to go outside to enjoy it.

6. IT'S ALSO A HEALTH HAZARD.

Even if DST was good for your energy bill, that wouldn’t negate the adverse impact it can have on human health. Numerous studies show that the extra hour of sleep we lose by springing ahead can affect us in dangerous ways. An increased risk of heart attack, stroke, and susceptibility to illness have all been linked to the time change.

7. BUT THERE ARE SOME BENEFITS.

Though people love to complain about it, Daylight Saving Time isn’t all bad news. One notable benefit of the change is a decrease in crime. According to one study published in 2015, daily incidents of robbery dropped by seven percent following the start of DST in the spring. This number was heavily skewed by a 27 percent dip in robberies during the well-lit evening hours.

8. IT'S NOT OBSERVED NATIONWIDE.

DST has been widely accepted across the country, but it's still not mandated by federal law. U.S. residents resistant to springing forward and falling back each year might consider moving to Arizona. The state isn’t exactly desperate for extra sunlight, so every spring they skip the time jump. This leaves the Navajo Nation, which does observe the change, in a peculiar situation. The reservation is fully located within Arizona, and the smaller Hopi reservation is fully located within the Navajo Nation. The Hopi ignores DST like the rest of Arizona, making the Navajo Nation a Daylight Saving doughnut of sorts, suspended one hour in the future for half the year.

9. IT STARTS AT 2 A.M. FOR A REASON.

Daylight Saving Time doesn’t begin at the stroke of midnight like you might expect it to. Rather, the time change is delayed until most people (hopefully) aren’t awake to notice it. By waiting until two in the morning to give or take an hour, the idea is that most workers with early shifts will still be in bed and most bars and restaurants will already be closed.

10. THE CANDY INDUSTRY LOBBIED FOR AN EXTENSION.

Until recently, losing an hour of daylight in the fall presented a problem for the candy industry. That’s because Daylight Saving Time traditionally ended on the last Sunday in October, a.k.a. before Halloween night. Intense lobbying to push back the date went on for decades. According to one report, candy lobbyists even went so far as to place tiny candy pumpkins on the seats of everyone in the Senate in 1986. A law extending DST into November finally went into effect in 2007.

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History
The Queen of Code: Remembering Grace Hopper
By Lynn Gilbert, CC BY-SA 4.0, Wikimedia Commons

Grace Hopper was a computing pioneer. She coined the term "computer bug" after finding a moth stuck inside Harvard's Mark II computer in 1947 (which in turn led to the term "debug," meaning solving problems in computer code). She did the foundational work that led to the COBOL programming language, used in mission-critical computing systems for decades (including today). She worked in World War II using very early computers to help end the war. When she retired from the U.S. Navy at age 79, she was the oldest active-duty commissioned officer in the service. Hopper, who was born on this day in 1906, is a hero of computing and a brilliant role model, but not many people know her story.

In this short documentary from FiveThirtyEight, directed by Gillian Jacobs, we learned about Grace Hopper from several biographers, archival photographs, and footage of her speaking in her later years. If you've never heard of Grace Hopper, or you're even vaguely interested in the history of computing or women in computing, this is a must-watch:

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science
Why Are Glaciers Blue?
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The bright azure blue sported by many glaciers is one of nature's most stunning hues. But how does it happen, when the snow we see is usually white? As Joe Hanson of It's Okay to Be Smart explains in the video below, the snow and ice we see mostly looks white, cloudy, or clear because all of the visible light striking its surface is reflected back to us. But glaciers have a totally different structure—their many layers of tightly compressed snow means light has to travel much further, and is scattered many times throughout the depths. As the light bounces around, the light at the red and yellow end of the spectrum gets absorbed thanks to the vibrations of the water molecules inside the ice, leaving only blue and green light behind. For the details of exactly why that happens, check out Hanson's trip to Alaska's beautiful (and endangered) Mendenhall Glacier below.

[h/t The Kid Should See This]

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