From the history of Daylight Saving Time to the mechanics of a clock, we look at some of the ways humans interact with time.
1914-1918: World War I prompts European countries to adopt Daylight Saving Time (DST) in order to cut back on fuel costs used for artificial lighting.
1918: President Woodrow Wilson officially implements DST across the United States.
1919: Many U.S. residents – especially farmers – rally against DST, making it a contentious issue across the country. The federal DST act is repealed, and the issue is taken up on the state and local levels.
1919-1942: States, counties and local municipalities have inconsistent application of DST.
1942-1945: World War II brings renewed interest in energy conservation, and President Franklin Roosevelt institutes a year-round DST known as “War Time.”
1945-1966: “War Time” ends, and the country resumes local discretion for implementation of DST, at times causing chaotic time discrepancies. The Twin Cities of Minneapolis and St. Paul, Minn., for example, held different times.
1966-present: The Uniform Time Act is established to create consistent application of DST across the country. States are allowed to opt out, but only if the entire state conforms.
“Because of the devilish daylight saving we now have baseball at night. Each block has half a dozen crackpots, each equipped with a radio capable of being heard for a half mile or more in all directions. This symphony of baseball broadcasts clawing at one’s nerves, begins when the blessed darkness finally comes. And it lasts to midnight, leaving the still partially sane sufferers to seek their sleep in a condition of hysteria.” – Aug. 10, 1940, letter from a disgruntled citizen to a Syracuse, N.Y., newspaper
(Map credit: TimeZonesBoy)
Though you might use your phone as your primary source for timekeeping, standard pendulum and mechanical clocks have been helping humans keep track of time without a need for electricity for more than 300 years. But how exactly do they work?
Pendulum clocks use weights and gravity to keep a constant back-and-forth swing on a pendulum – a rod or string with a weight attached to it. The time it takes for the pendulum to swing back and forth remains consistent. As the pendulum swings, it hits a lever called an escapement. The escapement locks and then unlocks the falling weight being used to keep the pendulum in motion, creating the “tick” (locking) and “tock” (unlocking) sound you’ll hear on all pendulum clocks.
Mechanical clocks use gears, a pendulum and a mainspring to display time. To make it work, mechanical clocks are wound up using a key. This winding causes the mainspring to tighten. As it unwinds, its energy turns the gears that cause gears to rotate, forcing the hands on the face of the clock to move over a specific period of time.
The rise of the railroad in the 19th century popularized the standard pocket watch. Train schedules not only made commuters more aware of to-the-minute time, but also created an important time-based structure for conductors. As railroads often use one track for train routes that might be headed in opposite directions, standardizing time became a crucial component of preventing collisions. Railroad companies began to issue “railroad standard” watches to train conductors and engineers, regulating specific watches for use on the job to create a better unification of time.
Radio-controlled clocks are designed to receive radio signals that allow them to be perfectly synchronized with an atomic clock. That clock is set up and operated by the National Institute of Standards and Technology (NIST), located in Boulder, Colo. NIST operates a radio station which transmits time codes to radio-controlled clocks and wristwatches across the country.
Sources: National Association of Watch and Clock Collectors, NIST.gov, Chris Woodford (2010, Pendulum Clocks)
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