Path: csiph.com!feeder.erje.net!1.us.feeder.erje.net!news.alt.net From: "James Wilkinson Sword" Newsgroups: alt.comp.hardware.pc-homebuilt,comp.lang.c,comp.lang.ada,comp.programming,alt.comp.os.windows-10,alt.os.linux.ubuntu Subject: Re: 'Leap Second' to Be Added on New Year's Eve This Year Date: Wed, 04 Jan 2017 21:03:12 -0000 Organization: ~ Lines: 80 Message-ID: References: <5f5afd36-1ba2-f4e2-62ef-57a652f3170c@verizon.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Content-Transfer-Encoding: Quoted-Printable User-Agent: Opera Mail/1.0 (Win32) Xref: csiph.com alt.comp.hardware.pc-homebuilt:35517 comp.lang.c:101131 comp.lang.ada:32697 comp.programming:7258 alt.comp.os.windows-10:32601 alt.os.linux.ubuntu:194669 On Wed, 04 Jan 2017 16:17:12 -0000, Richard Heathfield = wrote: > On 04/01/17 01:06, James R. Kuyper wrote: >> On 12/31/2016 04:57 PM, James Wilkinson Sword wrote: >>> On Thu, 22 Dec 2016 13:43:58 -0000, Mr. Man-wai Chang >>> wrote: >> ... >>>> A "leap second" will be added to the world's official clocks on Dec= . 31 >>>> at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (= UTC), >>>> which corresponds to 6:59:59 p.m. EST; the clocks will read 23:59:6= 0 >>>> before ticking over to midnight. The goal is to keep two different >>>> timescales in sync with each other. >>>> >>>> The units of time had long been defined based on Earth's rotation >>>> relative to distant celestial bodies. But that changed with the >>>> invention of atomic clocks in the mid-20th century; scientists then= >>>> decided to base the second on the natural vibrations of the cesium = atom. >>>> [How to Build the Most Accurate Atomic Clocks (Video)] >>>> >>>> These two timescales don't match up exactly, however. Measurements = show >>>> that, because the moon's gravitational pull and other factors are >>>> gradually slowing Earth's spin, the rotation-based scale loses betw= een >>>> 1.5 and 2 milliseconds per day compared to atomic time =E2=80=94 me= aning the two >>>> diverge by a full second every 500 to 750 days. >>>> >>>> Leap seconds are a way to make up for this difference. Since 1972, = the >>>> International Earth Rotation and Reference Systems Service (IERS) =E2= =80=94 the >> >> That name always struck me as rather funny - it seems to imply that >> they're responsible for making the Earth rotate. What they're actuall= y >> responsible for is keeping track of the Earth's rotation. >> >>>> organization that keeps track of time for the world =E2=80=94 has a= dded 26 leap >>>> seconds to atomic clocks, with the last such insertion coming on Ju= ne >>>> 30, 2015. >>>> >>>> The aim is to keep the two timescales within 0.9 seconds of each >>>> other. >> ... >>> I wish they'd turn their attentions to not turning the clocks back a= nd >>> forth all the fucking time! >> >> If you could make the Earth rotate at a fixed rate, there would be no= >> need for leap seconds. It's perfect feasible, though the costs would = be >> astronomical. Would you care to pay enough in taxes to make that happ= en? > > > You missed his point. He's not talking about leap seconds now, but abo= ut > Daylight Saving Time. He thinks it's stupid that we keep putting our > clocks forward an hour in the spring and an hour back in the evening -= -- > and he's right. Those who are familiar with his output should not be > /too/ surprised that he's right --- even a stopped clock can be right > twice a day. Also, I've yet to see a reason why we can't just live with being 1 secon= d different to sunrise.... -- = Do infants have as much fun in their infancy as adults do in adultery?