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    Re: Solstice in twelve hours
    From: Frank Reed
    Date: 2015 Dec 21, 13:11 -0800

    Ha! Hewitt (by email), Gary, and Antoine: At first I couldn't firgure out what you three were complaining about... objecting to the fourth digit past the decimal point perhaps?! Anyway, I finally spotted my typo and have fixed it in the original (with a note that it's been fixed). Yes, it's -23.4345, not -22.4345.

    By the way, the tilt of the Earth's axis is currently decreasing at a rate of about 0.01° per century. So if, like me, you first learned the axial tilt, also known as the "obliquity of the ecliptic", from a dusty old book, then you should know that the "odometer" has rolled down by two "ticks": the value of 23.45° has been succeeded by 23.44° and now it's already beginning to round down to 23.43° (to the nearest hundredth). Of course that won't get to my "typo" value at that steady rate. It oscillates back and forth. But in about 50,000 years, on the next downard oscillation, the tilt should briefly reach the mid 22's before shooting back above 24. :)

    Frank Reed
    ReedNavigation.com
    Conanicut Island USA

       
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