The average human life expectancy varies by the country, but in most developed portions of the globe, the average human will live between 75 and 80 years. To most, that sounds like a moderately long time. That number, however, is nothing in the grand scheme of things. Try imagining where humanity will be in a million years, and then, try doing the same thing with one billion years. By that point in time, it's more likely than not that humanity will be completely wiped out, if we haven't managed to take flight yet, but at science can at least predict the fate of one extraordinary piece of technology.

Researchers from NIST and the University of Colorado (a collaboration for the Joint Institute for Laboratory Astrophysics), have developed a new atomic clock that's so precise, it clobbers all preexisting records. It's so precise, in fact, that it will still be accurate — neither a second will be gained or lost — when the Sun bids the universe farewell about 4 to 5 billion years from now (the approximate span of time in which Earth has currently existed).

JILA’s Atomic Clock (Image Credit: The Ye group and Brad Baxley, JILA)

The device, a strontium lattice clock, is about 40 to 50 percent more accurate than the one developed by the National Institute of Standards and Technology (NIST), the "quantum logic clock," which held the previous record (it can keep time with a precision of 3.7 billion years). They keep time by measuring the vibrational frequency of UV lasers (the difference being, some use aluminum and magnesium ions, while others use aluminum and beryllium. The new clock instead uses neutral atoms like strontium and ytterbium)

When they first unveiled the clock at the beginning of the year, the researchers explained:

During this period in time, the Group leader, Dr Jun Ye , remarked: "We already have plans to push the performance even more." "So in this sense, even this new 'Nature' paper represents only a mid-term report." "You can expect more new breakthroughs in our clocks in the next five to 10 years."

In fact, the team have set their goals high, saying to NPR, "Our aim is that we'll have a clock that, during the entire age of the universe, would not have lost a second."

A visual demonstration of time dilation (Original Author Unknown)

However, like in all things, there are complications. This time, the complications stem from 'relativistic effects,' namely something called time dilation. It essentially tells us that time isn't as fluid as you might expect it to be. Instead, the rate at which time flows can be influenced by gravity (special relativity 101). For instance, time is different near the event horizon of a black hole, and to a lesser degree, time is different for us on the ground than it is for astronauts living aboard the International Space Station (ISS). 

As such, even moving a clock — any clock — from the floor to the wall would have a near infinitesimally small effect that would add up over time for an atomic clock. "Lift it just a couple of centimeters and you will start to see that difference," Ye said, "The time will speed up by about one part in 1016." 

"This new clock can sense the pace of time speeding up as it moves inch by inch away from the earth's core.

"That's a problem, because to actually use time, you need different clocks to agree on the time. Think about it: If I say, 'let's meet at 3:30,' we use our watches. But imagine a world in which your watch starts to tick faster, because you're working on the floor above me. Your 3:30 happens earlier than mine, and we miss our appointment."

"This clock works like that. Tiny shifts in the earth's crust can throw it off, even when it's sitting still. Even if two of them are synchronized, their different rates of ticking mean they will soon be out of synch. They will never agree."

Ye goes on to remark that, for these reasons, the best place for the clock would be in space itself, which is an interesting concept given the fact that Earth will one day die, probably long before the Sun does. This clock could be one of the last working human time capsules (though the scientists didn't specify how long it's "fuel source" would last).

Either way, Ye is clear, "At this level, maintaining absolute time scale on earth is in fact turning into nightmare,"


Share This Article