TECHNOLOGY

With the advent of ever-more-accurate clocks, keeping good time is becoming surprisingly complicated. (Nat Geo News)

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit, including today’s MapMaker Interactive map—and a round-up of other interesting reads this week.

Note: Current Event Connections is slowing down for the summer. Our column will continue to appear once or twice a week until mid-August. If you have an idea for a Current Event Connection, a recommendation for a good read, or want to share one of your MapMaker Interactive maps, let us know in the comments!

Discussion Ideas

• Watch the short Nat Geo video above. What is a leap second?
  • Leap seconds are seconds added to official timekeepers to keep the time we use (on our watches, clocks, computers, and other devices) closely in sync with the actual rotation of the Earth.

• Why does time need be adjusted?
  • Earth is a pretty dynamic place, and natural events such as earthquakes and volcanoes change the speed of the Earth’s rotation “ever so slightly” every year, according to the Nat Geo video.

• Are leap seconds added every four years, like leap years?
  • Nope. Leap seconds are added whenever the Earth’s rotation changes by .9 second. This can be once every couple of years, or several times in a shorter period. According to Nat Geo News, “in the early 1980s, time scientists were adding them every year.”

• Will this impact your smartphone or computer?
  • Unlikely, but remains to be seen. The group that decides when to add a leap second (the International Earth Rotation and Reference Systems Service) gives the announcement six months in advance, so organizations can have time to adjust their clocks. This extra second keeps computer programmers on their toes.
    • In 2012, the last time a leap second was added, the extra second crashed Reddit, Gawker, and Mozilla (Firefox).
    • The New York Stock Exchange is closing a half-hour early to allow its programmers to adjust to the leap second.
    • At the National Institute of Standards and Technology, one physicist admits “There’s a full panic mode just before and after” the leap second is added.
    • Apple and Google devices will automatically update or sync to the leap second.
    • Windows devices will ignore the leap second.

• Satellites of the Global Positioning System uses time to calculate locations. Will the GPS navigation on your smartphone or in your car be impacted by the leap second?
  • Nope. According to Nat Geo News, “true GPS time is off from civilian time by something like 16 seconds . . . Navigation services . . . like GPS never use leap seconds. . . because they need accurate measures of time in their calculations. If they stopped their internal clocks for the leap second, they would get inaccurate positions. The end-user isn’t aware of this because the GPS system will still send information to the receivers we use . . . about the leap second.”

TEACHERS’ TOOLKIT

Nat Geo: Why Time Will Stop For a Leap Second

Nat Geo: Time Stops! For a leap second . . . map

THIS WEEK AROUND NAT GEO

• Climb El Capitan from the Comfort of Your Computer
• Kiki or Bouba: What Is the Shape of Your Taste? Our experience of food may involve a form of synesthesia, a rare neurological condition in which certain senses seem to be cross-wired. This is fascinating.

THIS WEEK AROUND THE WEB

• Explore America’s 11 Most Endangered Historic Places, from the Grand Canyon to Little Havana.
• Snapshot Serengeti. Serengeti National Park, Tanzania, needs your help to classify all the different animals caught in millions of camera-trap images. Armchair citizen science at its finest.
• Eight Things You Think Are True, but Science Scoffs At. What? The five-second rule isn’t sound science?
• Mets Fans: Not So Amazin’ at Spelling and Grammar. Cleveland tops the power rankings here.
• How a Persistent, but Quiet, Campaign Made Lunar New Year a School Holiday in New York
• Why Police Don’t Pull Guns in Many Democratic Countries
• Where is the Heart of the Somali Film Industry? Columbus, Ohio.
• Interiority Complex. This gorgeous photography project is shedding light on Russia’s diverse regions. “Our people’s idea of geography is an absolute mess.”
• In the Kingdom of the Bored, the One-Armed Bandit is King. McLuhan was right. The medium is the message massage.