Winter has just begun!

December 21, 2021 • 9:59 am

Yes, when this post goes up at 10:59 a.m. Eastern U.S. time, Winter in the Northern Hemisphere has just begun.  I thought it would be a good winter, but it looks like we’re in for another long bout of social distancing, mask wearing, people avoidance, and maybe even another jab.  I hope to still go to Antarctica in March, and if that doesn’t happen I’ll be bummed.

A quick explanation of the solstice: because the Earth orbits the Sun but its axis of rotation is tilted at a constant angle, this is the day when the Northern Hemisphere is farthest from the Sun, while the Southern Hemisphere is closest. That’s why it’s the beginning of Summer below the equator and the beginning of Winter here (just that slight tilt makes all the difference in weather and light). It’s the shortest day of the year for us, and the longest day of the year below the equator.  This diagram explains both the light and temperature phenomena.

Will it be a good winter (either for you or the world) or a bad one?  A dumb poll:

Will it be a good winter or a bad one

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48 thoughts on “Winter has just begun!

    1. Good good good!

      Rage against the Seasonal Affective Disorder!

      For a nice computational mind melt, consider this : calculating a plot of daylight, as seen in those Mercator projections with day/night laid on them :

      Some sites I found :

    2. Meant as stand-alone comment – I dig the pun though.

      Thank PCC(E) (Paws Be Upon Him), the comment appeared, though it should not have!

  1. I thought it would be a good winter, but it looks like we’re in for another long bout of social distancing, mask wearing, people avoidance, and maybe even another jab.

    Or as Richard the Trey might say, yet another winter of our discontent.

    1. Ironically, winter is THE thematic season of the York Peppermint Patty, contrary to Richard’s admittedly snide reference to the glorious summer brought by the sun (son) of York.


  2. I voted ‘good’, although it is summer now here.
    I have this hunch -an informed hunch- omicron will be a blessing in disguise.

  3. Hey Jerry, you have it all wrong. This is the real reason why winter has begun:

    Tāwhirimātea’s battle

    In Māori tradition, Tāwhirimātea was the god of the weather. His parents were Ranginui (the sky father) and Papatūānuku (the earth mother), who lay close together. To let light into the world, Tāwhirimātea’s brothers separated their parents. But Tāwhirimātea did not agree to this. To show his anger he sent out his children, the four winds, and clouds that brought rain and thunderstorms.

    This destroyed trees in the forests ruled by his brother Tāne. But Tāwhirimātea could not defeat his brother Tūmatauenga, god of the people. So the battle between people and the weather continues today.

    1. Thanks for that information. For many decades, I thought Pluto, Proserpina and Ceres were responsible, but as an Antipodean I obviously need to decolonise my mind and learn True Indigenous Knowledge.

      Hmmm, ‘Antipodean’? That sounds like colonial knowledge hegemony to me.

  4. Testing … I put a comment with three links – bad form? I’d like to repost that a different way if my previous comment is denied.

    1. That’s always puzzled me. Why would the shortest day mark the beginning and not the the middle of winter? After all, “In the bleak midwinter” was originally published under the title “A Christmas Carol”. Is this a US thing where things start later than elsewhere in the world, as in Johny Horton’s classic “Sink the Bismark (sic)” – “In May of nineteen forty-one the war had just begun”?

      1. > Why would the shortest day mark the beginning and not the the middle of winter?

        There are several working definitions of ‘winter’ (etc.). My understanding is that astronomical winter runs from the Winter Solstice to the Spring Equinox. Meterological winter is climate-based and varies from geographic location to location. Check out a Cherry Blossom Map or a Foliage Map to see how local definitions of seasons can differ, even between people a few hundred kilometers apart.

        1. Here in Sweden we want 5 consecutive days with average below 0 degC, so the 2020/2021 winter started in Februari this year. The national weather institute describes the definition as mostly for amusing people, so don’t take it too seriously. Since spring has a more calendar bound definition, it should have 7 consecutive days above 0 degC but can’t start before February 15, some locales have had “undefined season” until that date some years.

          Can we have Yule despite having had no winter? You bet we can!

      2. It’s not just a US thing: I remember hearing it as a child in Britain. It didn’t make sense to me then and it doesn’t now.

        As for the Bismark (sic) quote. Is it genuine? For Americans, the war had not yet begun and for there British it had been going on for a year and a half. You can make an argument that it really began in 1937 with Japan’s invasion of China.

        1. Wow. Six edits so far.

          1. One edit to get it posted as a reply to the right comment
          2. Three edits to get Bismarj to Bismark without a c, thanks autocorrect.
          3. Two edits to get “just” inserted in the correct place.

    2. I think in a maritime climate the shortest day of the year makes sense as mid-winter. But there’s clearly a lot more cold after that day, compared to before it, in a continental climate.

      Why not have the months of Dec., Jan., Feb. as winter—and then similarly 3 actual months for the other three seasons? Anywhere north of the equator, the 1st three weeks of March is a hell of a lot nicer than similar for December,

      1. “Anywhere north of the equator, the 1st three weeks of March is a hell of a lot nicer than similar for December,”

        Nicer is relative. I’m in south Florida and can spend many days at the pool at 81 F in December as well as March. When I spent winters in Massachusetts or NY, there were many blizzards in March and even occasionally in April.

        1. I hesitated when writing the universal quantifier “anywhere”, and cannot dispute your anecdote. But I thought that true Floridians shiver, and thus whine, even at 81F !

          My anecdote is going in the 1963 Landrover camper down to Florida at Xmas 1973 with my young children, and freezing our butts off overnight. But that was unusual weather perhaps.

          Blizzards are welcome, at least for me–I skied through the city to work once even in April.

          Anyway, what I said is literally false, statistically true. Maybe “nicer” should be ‘less dreary’, at least for lovers of light.

            1. I always hesitate on that one–maybe it should be ‘skiied’??

              When the Babe popped up, he skyed it, right? But not ‘poped up’. To ‘pope up’ is to claim infallibility, surely.

    3. Quite right – sort of. Meteorologists start the season on 1st Dec, likewise 3 month seasons so summer begins on 1st of June NOT at midsummer. Midwinter is therefore mid January.

  5. Interestingly, because the earth’s orbit is elliptical, it is currently almost at its closest distance to the sun, and will be around 5 million km further away in the Northern hemisphere summer.

    The seasons arise not because of greater distance from the sun but because during the Northern hemisphere winter the same amount of solar energy is spread over a larger surface area at higher latitudes because of the tilt of the earth’s axis.

    Meanwhile, in Auckland NZ, it is a pretty hot summer and I have been planting runner beans, tomatoes, and chillis. Few of the bean seeds have germinated, possibly because I failed to heed the advice of maramataka, the Māori calendar, as to the to best time of the lunar month for planting:

    I can’t answer the poll because it’s not winter here, but I can wish all readers a happy festive season, however they may celebrate it.

    1. ” . . . I have been planting runner beans . . . .”

      Where I grew up (in E. Tennessee adjacent to the Great Smoky Mountains National Park), over the years I often heard locals speak of growing “half-runners” beans. I’ve put on my “To Do” list to find out what that means. Do you know? Are there 3/4 runners? The square root of -1 runners? 😉

      1. I’d not heard the term before, but Google is your friend:

        They look similar to what I’d refer to as “french”, “round”, or just “green” beans.

        Runner beans, also often called “scarlet runners”, are different, with flat pods:

        They are my favourite, and indeed favorite, of the green beans, but less common and much more expensive in the shops here.

      2. I asked a friend with a PhD in botany about this and received rather more information than I was expecting.

        “The term runner bean could refer to two or more species. First, there is the common bean, Phaseolus vulgaris, first domesticated in Central and South America. Many, if not most, of the beans you grow and eat belong to this species, including haricot beans, green beans, baked beans (called navy beans), kidney beans, pinto beans, and so on. The original wild bean had a climbing habit, but most of the cultivated forms have a bush habit. The half runner beans you asked about presumably retain a predeliction to climb. The other species is the scarlet runner bean, Phaseolus coccineus, which also originated in the Americas. This is actually a perennial, but is grown as an annual in Britain, and is recognisable by its bright red flowers. This bean, a favourite with bean slicers, doesn’t seem to be grown so much in Australia. ”

  6. PCC(e)—Thanks for reminding us that “Soylent Green” takes place in 2022. Maybe I will celebrate the new year by watching it again, Netflix permitting. Bon voyage á Antarctica.

    1. Coincidentally enough I’ve just finished re-reading “Make Room, Make Room” by Harry Harrison, the novel on which Soylent Green was based. The novel is set in 1999, 33 years after it was written, when without birth control the population of New York City was, according to Harrison, 35 million. The internets tell me that NYC actually had a population of 8.4 million in 2019. And the bit about Soylent Green being made out of …you know what (no spoilers) is only in the film, not the book.

      1. The classic sci-fi depiction of a dystopian future of overpopulation and resource exhaustion was written much earlier, in 1952. It is “The Space Merchants” by Cyril Kornbluth and Frederik Pohl,
        which uses the conventions of space opera for a biting, astonishingly prescient satire on all aspects of consumer society. Kornbluth died in 1958, and Fred Pohl alone wrote the novel’s sequel, “The Merchants’ War” (1984), and published a revised version of “Space Merchants” in 2011. The original, which I reread periodically with astonishment at its acuity, is regularly listed among the best science fiction novels.

        1. “The Space Merchants” is a great book. I was initially alerted to its existence by the English novelist Kingsley Amis’s book of SF “New Maps of Hell” – he was a big fan

  7. The best thing about the winter solstice is that the days start to get longer again. Yay! Sure, cold and snow lie ahead, but more daylight.
    For extra credit, explain why in my latitude (43.3 N), the earliest sunset (clock time) occurred about 9 Dec but the latest sunrise will not occur until about 10 January. Hint: It is part of the observational proof that the sun and the stars do not revolve around the earth.

    1. This is true at all latitudes, not just 43.3 N, and it’s because the Sun sometimes runs fast relative to local mean time and sometimes runs slow. If you’re on the Greenwich meridian, for example, the Sun is hardly ever due south at exactly 12:00 GMT. Most of the year, it’s due south earlier than 12:00 or later than 12:00, by as much as fifteen minutes. The underlying cause is two-fold: first, the Sun moves along the ecliptic, which is tilted relative to the equator by 23.5 degrees, more or less, and second, because the Earth’s orbit is elliptical not circular, it’s not moving around the ecliptic at a uniform speed. Consequently, in technical terms, the Right Ascension of the Sun does not increase at a uniform rate.

      I’m not sure what this has to do with proving that the Sun and stars don’t revolve around the Earth. The aberration of starlight, discovered by James Bradley in 1727, was the key observation which settled that question.

      1. Yes, the effect exists at all latitudes. It’s just that the precise day at which the December sun gets most out of kilter with the clock varies some as you go closer to the Pole. In Tuktoyaktuk NWT, the sun set at 14:04 on 27 November and will not rise again until 13:49 on 13 Jan. If I hadn’t specified my latitude, someone would have pointed out that where she was, her earliest sunset had occurred at some different date from where I am. In Peace River, Alberta, earliest sunset was 13 Dec. In Houston, Texas, it occurred about the end of November and had already gained a full minute by 9 Dec. (The actual local time of sunset additionally depends on where you are east-west in your time zone, of course.)

        For the solar system, the sidereal day of 23 hr 56 min (which you can measure with an ordinary clock using the circumpolar stars) is less than the 24 hours we define as the solar day, noon to noon. If the solar day were constant, it would be straightforward to show that the sidereal day is always 4 minutes less than the solar day. This would refute the concept that the sun and the stars were points of light fixed to the inside of a rotating celestial sphere — instead the sun must be moving independent of the stars. A solar sphere with a period of 24 hours and a star sphere with period 4 minutes less would be possible to imagine but messy: why would the creator go to so much trouble for 4 minutes? Proposing that the earth rotates on its axis while it revolves around the sun in the same counter-clockwise direction — topspin not backspin — solves the 4 minutes quite neatly. Not proof but the insight gained from precise time-keeping that star time didn’t equal solar time must have stunned all who shared it.


        Before you can measure the rotational period of the circumpolar stars, you have to be able to “keep time.”. You must regulate your brand new, first-ever mechanical clock so that it ticks out 24 hours accurately and reliably in one noon-to-noon interval. That’s when you make the other (first actually) astounding discovery that the solar day is not constant but shortens and lengthens through the year, as David describes. This is another feature not contemplated by geocentric universes. Now your “solar sphere” has to speed up and slow down in a periodic manner so the sun still returns to its proper place from year to year….and then you have axial precession to explain!

        Of course, at first your critics scoff, suspecting your clock must have more slop in its works than God would put in the universe. Yet as your clocks get better, you find that the error (now called the equation of time) cycles back to zero (within mechanical limits) from one winter solstice to the next. From this time on you measure the day according to clock time instead of setting your clock against the sun — a cultural revolution if there ever was one. Your discovery that the solar day varies more than your clock does, fully justifies you to conclude that sidereal day is shorter than mean solar day averaged out through the year. One series of careful observations impossible to all previous civilizations provides two nails in the coffin of a perfect geocentric universe of a celestial sphere revolving around a fixed earth.

        Proving the correct hypothesis, that the earth itself actually does move, i.e. through measuring stellar aberration and then understanding it in relativistic terms is another matter. But observations that the geocentric universe cannot be correct pave the way, conceptually, if not in fact historically. And my point was to illustrate how ordinary observations understandable to lay people can help answer the question, “How do scientists know the earth goes around the sun when it seems obvious that it’s the heavenly bodies that move, not the earth?” My other point was to show how there has to be some source of external validity to the claim that the earth rotates once in 4 minutes less than a day and that the day itself is not always exactly 24 hours long. Lay people are entitled to ask, “How do you test a clock to be sure that the day is varying, not the clock?”

        1. Much thanks for your thoughtful exposition.

          I remember my navigation class at U.S. Navy OCS. I quite enjoyed that, though the instructor was not inclined to give the etymology/history of “sidereal” and “local,” as in “SHA (“Sidereal Hour Angle”) and “LHA” (“Local Hour Angle”). It was all practical, instrumental, procedural knowledge. Otherwise, perhaps I would not have had to memorize so much by brute force. (No history of Maori navigation was presented.)

    1. I guess at some level, it is something somewhere – and the opposite opposite that – the equator – s’allways summer there, right?… orrr… perhaps slightly cooler when Earth is farthest from the sun?…

  8. Readers may also be interested in the Tangaroa of Pipiri method used to calculate the date of Matariki, the Māori New Year, and New Zealand’s newest public holiday. The dates until 2052 were decided by a committee of experts, who say that “the methodology and dates presented here have been rigorously discussed in conjunction with multiple techniques used to calculate and cross check the integrity of the dates.”

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