Nevada Appeal at 150: Dec. 31, 1975: New Year’s Day one second late

New Year 1976 will be one second late.

Thousands of atomic clocks used around the world as the official standards of time will be staggered one second tonight to make up for a slowdown in the earth’s rotation.

“Unfortunately the earth is a lousy clock,” said Dr. James Barnes of the National Bureau of Standards. “Atomic clocks are maybe 100,000 or a million times more accurate than the spinning earth.”

Barnes said the extra second will guarantee the time on commercial clocks will coincide with the atomic clocks used by scientists, navigators and television networks.

“It’s all done electronically,” he said. “What will happen is that there will be 61 impulses in the counting process during the final minutes of the year in Greenwich, England.”

Greenwich time is five hours ahead of Eastern Standard Time in the United States, so the “leap second” will be added to atomic clocks in New York at 5 p.m. (EST) New Year’s Eve.

“All we do is flip what is called an ‘enabling switch’ anytime during the 24 hours before we want the extra second to be added,” said Barnes. “It’s all programmed in a computer and it’s very simple. I won’t even have to be here.”

The “enabling switch” is simply a toggle switch inside the room housing the atomic clocks, three clock faces and a computer. Once the extra second is added, the switch is flipped back into place until the next time it is needed.

This is the fourth consecutive year the atomic clocks have been staggered since leap seconds were first used in January 1972. Two seconds were added in 1972, another in 1973 and a fourth in 1974.

“Prior to 1972 we used what might be called ‘rubber seconds,’” said Barnes. “We simply slowed up or sped up the clocks to keep up with the earth. The system of leap seconds allows the clocks to run at a constant pace but to still kick in an extra second when we need it.”

Atomic clocks first went into use Jan. 1, 1958. Since then, 15 rubber seconds and leap seconds have been added.

This continues the Appeal’s review of news stories and headlines during its Sesquicentennial year.


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