We might soon lose a full second of our lives

Date:
Mon, 20 Feb 2023 11:00:00 +0000

Description:
Some tech companies think a negative leap second would turn the world upside down. But it probably won't be that bad. Deposit Photos The Earth is spinning faster. A negative leap second could help the world's clocks catch up. The post We might soon lose a full second of our lives appeared first on Popular Science .

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Some tech companies think a negative leap second would turn the world upside down. But it probably won't be that bad. Deposit Photos

The leap seconds days, so to speak, are numbered . Late last year, the worlds timekeepers announced they would abandon the punctual convention in 2035 .

That still gives timekeepers a chance to invoke the leap second before its scheduled endin a more unconventional way. Ever since its creation, theyve only used positive leap seconds, adding a second to slow down the worlds clocks when they get too far ahead of Earths rotation.

As it happens, the worlds clocks arent ahead right now ; in fact, theyve fallen behind. If this trend holds up, its possible that the next leap second may be a negative one, removing a second to speed the human measure of time back up. Thats uncharted territory.

The majority of humans wont notice a missing second, just as they wouldnt
with an extra one. Computers and their networks, however, already have problems with positive leap seconds. While their operators can practice for when the worlds clocks skip a second, they wont know what a negative leap second can do until the big day happens (if it ever does).

Nobody knows how software systems will react to it, says Marina Gertsvolf , a researcher at the National Research Council, which is responsible for Canadas timekeeping.

The second is defined by a process that occurs in the nucleus of a cesium-155 atoma process that atomic clocks can calculate with stunning accuracy. But a day is based on how long the Earth takes to finish one full spin, which takes 24 hours or 86,400 of those seconds.

Except a day isnt always precisely 86,400 seconds, because the planets rotation isnt a constant. Everything from the mantle churning to the atmosphere moving to the moons gravity pulling can play with it, adding or subtracting a few milliseconds every day. Over time, those differences add
up.

[Related: What would happen if the Earth started to spin faster ]

An organization called the International Earth Rotation and Space Systems Service (IERS) is responsible for tracking and adjusting for the changes.
When the gulf widens by enough, they decree that the final minute of June 30 or December 31whichever comes next should be modified with a leap second . Since 1972, these judges of time have added 31 positive leap seconds.

But for the past several months, Earths rotation has been pacing ahead of the worlds clocks. If this continues, then its possible the next leap second
might be negative. At some point in the late 2020s or early 2030s, IERS might decide to peel away the last second of the last minute of June 30 or December 31, resulting in a minute thats 59 seconds long. Clocks would skip from 23:59:58 right to 00:00:00. And we dont know what that will do.

What we do know is the chaos that past positive leap seconds have caused. Its nothing like the apocalyptic collapse that Y2K preppers feared, but the time tweaks have given systems administrators their fair share of headaches. In 2012, a leap second glitched a servers Linux operating system and knocked out Reddit at midnight. In 2017, Cloudflarea major web service provider experienced a significant outage due to a leap second. Problems invariably arise when one computer or server talks to another computer or server that still might not have accounted for a leap second.

As a result, some of the leap seconds biggest critics have been tech
companies who have to deal with the consequences. And at least one of them is not excited about the possibility of a negative leap second. In 2022, two Facebook engineers wrote : The impact of a negative leap second has never
been tested on a large scale; it could have a devastating effect on the software relying on timers or schedulers.

Timekeepers, however, arent expecting a meltdown. Negative leap seconds arent quite as nasty as positive leap seconds, says Michael Wouters , a researcher at the National Measurement Institute, Australias peak measurement body.

[Related: Daylight saving can mess with circadian rhythm ]

Still, some organizations have already made emergency plans . Google, for instance, uses a process they call a smear. Rather than adding a second, it spread a positive leap second over the course of a day, making every second slightly longer to make up the difference. According to the company, it
tested the process for a negative leap second by making every second slightly shorter, amounting to a lost second over the course of the day.

Many servers get their time from constellations of navigation satellites like Americas GPS, Europes Galileo, and Chinas BeiDou. To read satellite data, servers typically rely on specialized receivers that translate signals into informationincluding the time. According to Wouters, many of those receivers manufacturers have tested to handle negative leap seconds. I think that there is a lot more awareness of leap seconds than in the past, says Wouters.

At the end of the day, the leap second is just an awkward, artificial construct. Human timekeepers use it to force the astronomical cycles that
once defined our time back into lockstep with the atomic physics that have replaced the stars. It removes this idea that time belongs to no country and no particular industrial interest, says Gertsvolf.

So, with the blessing of the worlds timekeepers, the leap second is on its
way out. If that goes according to plan, then we can let the Earth spin as it wants without having to skip a beat.

The post We might soon lose a full second of our lives appeared first on Popular Science . Articles may contain affiliate links which enable us to share in the revenue of any purchases made.



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Link to news story:
https://www.popsci.com/science/negative-leap-second/


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