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    News stories about "length of day" and leap seconds
    From: Frank Reed
    Date: 2025 Jul 22, 09:16 -0700

    There have been a number of small news stories talking about the length of the day and the issue of leap seconds in the past few weeks. Some of these stories are muddled ramblings with clickbait headlines. A few are closer to the science. This article from NPR (see PS) gets many of the details right, interviews a real expert, Dennis McCarthy, and comments on the borderline absurdity of some of the recent coverage:

    Scientific experts who constantly monitor the Earth's rotation seem a bit baffled and amused that a few slightly more-speedy-than-normal spins this summer have captured the public's imagination.

    Most of the genuinely goofy articles have already scrolled off. Here's an index from Google News that should include some of the latest, more sober coverage.

    There's talk about a possible "negative leap second" in the next few years. This would delete one second from the calendar, probably at the end of December or June (not this year). UTC would jump from 23:59:58.9999... to 00:00:00.0 skipping the last second of the last minute. Previous positive leap seconds, have added an additional second after the normal 59th second of the last minute, creating a 61-second minute (that would made the ancient Babylonians cry!). Since no negative leap second has ever been applied, there are significant doubts about the impact on computing systems, communications, etc. So why take the risk?? It would be a bad idea and un-necessary for any practical user group. There is a common mythology among some old school defenders of celestial navigation claiming that if UTC is out-of-synch with "Earth Orientation Time", then celestial navigation would no longer work. This just isn't so... So don't panic. 

    Frank Reed
    Clockwork Mapping / ReedNavigation.com
    Conanicut Island USA

    PS: For those unfamiliar with the acronym, especially outside the US, NPR is "National Public Radio". It is related to PBS, the "Public Broadcasting Service". NPR and PBS have long been strongholds of fact-based reporting, genuine journalism, as well as being excellent sources of science news and education.  US federal funding for NPR and PBS was recently killed by Republicans in the US Congress. This will not wipe out these news organizations, but science at every level is under massive attack in the US by the Trump administration, supported by the anti-intellectual MAGA rabble, and also Republicans in Congress more generally (though certainly not all Republicans). With everything else going on, few have time to pay attention to the destruction of science. It's a developing disaster...
    ...
    And now you may panic.

       
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