Happy winter solstice!
Today, at 17:47 GMT, the Sun reaches the southernmost point in its annual up-and-down journey in the sky. Because the Earth’s axis is tilted, the Sun gets higher in the sky in the summer, and lower in the winter. Today marks the moment when the center of the Sun just kisses that lowest point. From here on out, every day until the summer solstice next June, the Sun will get higher in the sky at local midday.
If you’re in the southern hemisphere, reverse that — replace higher with lower, winter with summer, color with colour, and peanut butter with Vegemite. I’d explain in detail, but that’s what you get for living standing on your heads all the time.
The winter solstice marks the longest night and shortest day of the year. However, it’s not when the Sun rises latest and sets earliest! The Earth has the unfortunate habit of orbiting the Sun in an ellipse, which screws things up a bit when it comes to timing. The actual rise and set times depend on your latitude, but for me, for example, in Boulder, the latest sunrise occurs in the first week of January, and the earliest sunset already happened in early December. Craziness! But the Earth is a crazy place.
If you want more information on this than you could possibly ever need, then try reading the Analemma website. Very cool stuff there. Or you could read what I wrote about this in 2005, 2006, 2007, and 2008.
Still and all, the good news here is that if you live above the equator, the days’re getting longer after today: the Sun will stay up a wee bit more every day. And that means soon it’ll be spring (when eggs will stand on end, just like they do EVERY FRAKKIN’ DAY), and then summer and then autumn and then we’ll be right back here again, as the Earth has done time and again, billions of times, and will continue to do so until the Sun swells into a red giant and consumes it in a fiery blaze of overwhelming solar red gigantism.
But until then, happy new year, too!
Image credit: NASA.
December 21st, 2009 at 10:32 am
I find it ironic and oddly disturbing that the ad at the top of this page right now is for viagra while the content of this post is the sun finally staying up for longer. In the words of Quagmire; giggity.
Now I just need to carve out more time in the longer day to see Avatar again.
December 21st, 2009 at 10:37 am
Here at 47.95 N (or so), earliest sunset was about Dec 11 (greatly confused by the mountain range to the west, but Phil has that problem too) and latest sunrise is about Jan 1.
(In a year when DST ends as late as possible, our latest wall clock sunrise appears to be Nov 6 (Saturday morning) if I did everything right, just to confuse things further. In other years, wall clock is the same Jan 1 as real clock.
Similar things happen at summer solstice (latest sunset early; earliest sunrise late).
I get confused and suffer headaches when I try to think about what happens between the tropic lines. So I don’t try often.
December 21st, 2009 at 10:40 am
I think you mean the EARLIEST sunset has already happened in early December (which I pointed out earlier today in my facebook status
I realized this many years ago when I moved back north and started rejoicing when the sunset started getting later which was a couple of weeks before the solstice. Early sunsets bother me more than late sunrises.
Oh, and don’t we have the “alignment with the galactic center” thingy today which will totally not effect us at all today but totally kill us three years from today.
December 21st, 2009 at 10:44 am
It was the weirdest thing in the world when I was in Brisbane, Australia in 1998 for Christmas, and was singing “Frosty the Snowman” and “Dashing Through the Snow” when it was 80 degrees outside.
Toilets flushed the other way, drains drained the opposite direction, dogs and cats living together…man, things were upside down and backwards
December 21st, 2009 at 10:57 am
Should I break out the eggs?
giggity.
Oh, yeah!
December 21st, 2009 at 11:01 am
I like this.
Happy new year to you too!
December 21st, 2009 at 11:09 am
snip “peanut butter with Vegemite. I’d explain in detail…” snip
Disappointed you didn’t really explain Vegemite in the blog. I suppose that’d be a lot more difficult than astronomy or rocket science.
December 21st, 2009 at 11:13 am
What? You wrote a book?
And we all know about standing an egg on end at the equinox, but did you know that on the solstice you can lay an egg on its side? It’s true! I just did it!
And I gotta agree with Jason on the “stay up longer” and the Viagra ad at the top. I hadn’t noticed that (I rarely look at the banner ads) until he pointed it out.
“Your comment is awaiting moderation“? Let me guess… It’s the “V word” in the previous paragraph?
December 21st, 2009 at 11:44 am
Actually, during the Summer, the Sun gets lower in the sky, as solstice, which marks the beginning of Summer, has already happened.
December 21st, 2009 at 11:46 am
I understand that Vegemite is the Australian equivalent to Lutefisk.
(See also the State of Wisconsin statute 101.58(2)(j)2.f, which states ““Toxic substance” does not include: … Lutefisk.”)
December 21st, 2009 at 12:02 pm
@ Ken B,
I’m sure that I’m not the only who Googled the statute reference to see if its true.
It is.
December 21st, 2009 at 12:15 pm
A very merry solstice and a happy perihelion to everybody on the blog
December 21st, 2009 at 12:22 pm
[...] (foto roubada ao post do Bad Astronomy? [...]
December 21st, 2009 at 12:41 pm
The Northern Hemisphere equivalent of Vegemite is Marmite, not peanut butter!
I hadn’t realised there was such an offset between the latest sunrise and earliest sunset, but the calculator shows that for here in Bergen (60 N and 5 E) there isn’t so much discrepancy in the rise and set times: the latest rise being between the 23 and 3o Dec and the earliest set between the 14 and 18 Dec. Maybe that’s why I’ve never noticed, or maybe it because the days are usually so grey at this time of year that its hard to tell whether the sun is up or not!
December 21st, 2009 at 1:35 pm
[...] You can stand an egg on end today. Just like any day of the year. As the bad astronomer points out every [...]
December 21st, 2009 at 1:55 pm
Ray:
You can skip Google, and go straight to the horse’s mouth. Get the statutes from the State of Wisconsin website:
http://www.legis.state.wi.us/statutes/Stat0101.pdf
(page 46, right-hand column)
December 21st, 2009 at 2:02 pm
Shouldn’t that be “solstitial” in the title?
December 21st, 2009 at 2:44 pm
Cath, yes, the earliest sunset/solstice and solstice/sunrise differences decrease with latitude (above the tropic and below the arctic circle). Above the arctic circle, things get…cold.
December 21st, 2009 at 3:05 pm
[...] Winter Solstice OK, I lied. Another post before Christmas. But only because this post amused me. First of all, I didn’t realize the sunrise/sunset part (apparently the earliest sunset [...]
December 21st, 2009 at 3:09 pm
@dmolavi – What? You were in my town and you didn’t say G’day?
I can see where you’re coming from with the whole “dashing through the snow” thing in mid-thirties Celcius and 95% humidity. Someone here tried to do something about it a few years ago. Try this on for size -
Dashing through the bush, in a rusty Holden ute,
Kicking up the dust, esky in the boot.
Kelpie by my side, singing Christmas songs,
It’s summer time and I am in my singlet, shorts and thongs.
Oh, jingle bells, jingle bells, jingle all the way,
Christmas in Australia on a scorching summer’s day, HEY!
Jingle bells, jingle bells, Christmas time is beaut…
Oh what fun it is to ride in a rusty Holden ute.
Let me know if you need anything translated.
December 21st, 2009 at 3:21 pm
An esky is a beer cooler, right? Why’s it in the boot? Wouldn’t it be easier to get to in the front seat?
What’s a Kelpie?
December 21st, 2009 at 3:34 pm
No, because the Kelpie’s in the front seat. It’s a dog. Unless you’re Irish, then it’s a supernatural water horse.
Of course, the song still makes no sense because a Holden ute (utility truck) doesn’t have a boot (trunk), it has a tray.
Australia is confusing sometimes. When it’s not deadly.
December 21st, 2009 at 3:43 pm
A small correction. While it is true that the day of earliest sunset comes some time before the solstice, and the day of latest sunrise comes about the same amount of time after the solstice, these discrepancies are not due to the eccentricity of the Earth’s orbit. The same thing would happen even if the orbit were exactly circular. The linked analemma site explains this.
December 21st, 2009 at 4:53 pm
Happy solstice day!
Here’s a 3-month-long exposure I took with a pinhole camera (solargraphy) and shutter closed today to mark the solstice. The streaks in the sky represent the movement of the sun (the camera is facing almost due south). The exposure started just a couple days after the autumnal equinox. The lowest streak of light represents today (and a few days preceding it, cuz it all gets mushed together), when sunrise/sunset positions are farthest south along the horizon, and the position of the sun at noon is lowest.
December 21st, 2009 at 4:58 pm
As an Aussie .. who detests vegemite .. it’s basically the scrapings of dog poo that have been walked into your shoe for a week, combined with some sump oil and then salt poured on.. or a yeast extract which is salty. Personally it makes my skin crawl. Can’t wait ’til the kids can make their own sangers put it that way.
I must admit though, the 35-40 celcius day we normally get over here really kills the love of a roast.
An esky/eskie is a plastic, lidded beer cooler.
A kelpie’s a working dog, lively & loyal.
A ute is a sedan with the rear half of the roof and boot lid removed (and no seats).
“Australia is confusing sometimes. When it’s not deadly.”
LOL, got that right, had to kill 4 redbacks before I could do the barbie (barbecue) last night!
December 21st, 2009 at 6:08 pm
As a star spangled ‘murican boy, I must say I love all things aussie with the exception of vegemite and the driving rules of the road in Melbourne. Being adventuresome, I did try some vegemite my first visit down under and I believe Yeebok’s description of it is 100% accurate. The fact that it seems to be so popular really makes me wonder about deleterious effects of living under the southern hemisphere’s sun. We’ll leave the issues of practically every living thing on the continent and in the waters wanting to kill you for another time.
December 21st, 2009 at 6:26 pm
Yes, I’ve heard interesting stories from people trying to take vegemite or marmite (In New Zealand we tend to have both, talk about factional battles!) through other countries customs checks. Apparantly you should avoid trying things like “No, it really is a spread, try some” (Correct approach “…watch me try some”)
Just came in from sitting on the grass in the park opposite work under the lovely sun having a christmas lunch with my workmates, you can keep your white chrstmas’s
December 21st, 2009 at 7:10 pm
Vegemite is way less gross than heaps of things you have in the U.S. For example, spray on cheese in a can, spray on marshmellows in a can, spam etc etc. And I don’t know anyone who eats vegemite straight out of the jar. You have to put it on toast with butter. It’s awesome.
Vegemite is also great on pancakes with maple syrup and bacon. OK that last one was just a joke. Only those crazy Americans would mix pancakes with savory foods such as bacon and eggs. You guys are totally gross.
December 21st, 2009 at 7:20 pm
In the hope that it would improve on the already rock-like foundation of the US-Australia alliance, Mrs Grendel eats peanut butter and vegemite sandwiches.
I myself prefer vegemite and banana sandwiches – but never when I have the telescope out as slices of banana have a disturbing habit of obscuring the eyepiece when they slip out of the sandwich.
Vegemite on hot buttered toast – or better yet, a hot buttered crumpet, is a thing of delight.
December 21st, 2009 at 7:26 pm
I bet JB and Tim Bennett know what it is like to do a Uie in the ute at the Uni while heading to the Chrissie barbie for a sanger or a snag and a stubbie.
December 21st, 2009 at 7:39 pm
My husband’s birthday is December 21st. He said he always thought he got gypped since his birthday was the shortest day of the year. I told him just think of it as the longest NIGHT of the year. Not so bad now, huh?
December 22nd, 2009 at 2:03 am
I actually eat peanut butter and Vegemite for breakfast. Also glad the sun didn’t sent until 21:30 where I am.
December 22nd, 2009 at 5:57 am
It’s *colour* for us Canadians too. In fact, I think it’s the American’s who simply don’t know how to spell.
December 22nd, 2009 at 6:01 am
Please try to use north and south instead of above and below as in, “Still and all, the good news here is that if you live above the equator”.
Also, how can it be that Miss Cellania has a husband? Confusing.
Finally, you can satisfy your curiosity by ordering VEGEMITE on-line from several sites and have it shipped to the USA…or anywhere else.
December 22nd, 2009 at 8:17 am
How can anyone live “above” the equator? Come on BA, you used to be a scientist…… be more precise in your use of words.
January 6th, 2010 at 1:40 pm
A little late to the party here, but could you debunk the “first day of” myth that accompanies every solstice or equinox? These dates should more appropriately be seen as the “middle” of their season. That’s why in historic times, the winter solstice was called mid-winter and the summer solstice was called mid-summer.
March 21st, 2011 at 1:55 am
@35. ozprof : Very, exceedingly, late to the party – by years – but dare I suggest a moored balloon or blimp or geosynchronous space station satellite is how?
January 1st, 2012 at 2:44 pm
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