I am very sorry, sir, I am behind my time...

It's only once a year, sir, it shall not be repeated.  I was making rather merry yesterday, sir.

Bob Cratchit from Charles Dicken's A Christmas Carol starring George C. Scott.  One of my favorite versions of the classic Christmas tale. 

Happy New Year!  Like Bob Cratchit, I am behind my time (by a day) and was making rather merry yesterday.  And in the process of welcoming 2014, I discovered something amazing.

For many years I have extolled the virtues of getting away from people to enjoy the sky.  Well, more specifically, people's lights.  The city is a terrible place to do astronomy...few stars can be seen, and finding a spot with open sky can prove challenging to say the least.  So I often recommend that folks go somewhere else to see the stars.  Areas with little population (Casper Mountain in Wyoming has astounding skies!), the desert southwest of the United States (my Dad, who loved to hike the Grand Canyon, bought a tent with a special skylight in it for stargazing...he said the sky from down in the canyon was the most incredible thing he'd ever seen), out on the water far away from shore (but not on most cruise ships, which are lit up like bonfires), and other such far away destinations have been my suggestion to people looking to see more of the sky than they usually do.

Or, you could drive about an hour west of Richmond.  No, really!

We generally spend New Year's Eve in a cabin at Bear Creek Lake State Park.  It's wonderful to get away from it all (there's no cell service or internet out there either!) and just enjoy some time with family and friends.  Most years, the sky has been cloudy...especially if I go through the trouble of packing my telescope.  This year, I said the heck with it, and left it home.

On New Year's Eve night we went out to build a fire and make s'mores (always a hit with the kids).  My friend suddenly said "Hey, look at the Milky Way!"

I looked up and almost fell over.

The sky was cold and clear and the air unmoving.  It was deep black, and spangled everywhere with stars so bright they seemed to leap out of the sky at me.  Jupiter shone like a beacon...for a moment, I was disoriented...I thought it was Venus, it seemed so bright to me!  As my eyes adjusted, I could see more and more faint stars playing in the background of the sky...and indeed, the lovely swath of the Milky Way, arcing high above us.  I wasted no time bemoaning my lack of a telescope - I simply took my daughter aside and we looked for constellations.  We spotted a couple of satellites and caught a few meteors in the bargain.  It was breathtaking, delightful, dizzying, and altogether awesome.

So here's my recommendation to you for a new year's resolution - make a reservation and stay at a State or National Park near you sometime this year.  You probably won't have to even travel very far!  Many parks offer traditional camping (bring your own tent) or cabins for rent (very reasonably priced, and come with all the comforts of home like heat, AC, and indoor plumbing!).  Some even have yurts (I hear they can be tons of fun!).  You can make reservations online at Reserve America.  It's great way to get some time away, bond with family and friends, explore your local area, and rediscover the sky.  Trust me, you'll love it.

One of the cabins at Bear Creek Lake State Park in Virginia.  Yes, it's as awesome as it looks.  Image by Tracey Shaffer courtesy Reserve America.

Here's hoping that 2014 is truly a stellar year for us all.
See you in two weeks, and until then...
Carpe Noctem!
Kelly

It's The End of the World As We Know It...

...and I feel fine!

Actually, I seem to have caught the delightful virus that's been making the rounds here in southeast Virginia.  On week 2 of the darn thing and I am ready to be done with it.  But back to the matter at hand...

Holy cow!  The world is coming to an end this Friday!  The Mayan Long Count calendar says so!

The Seven-Day Forecast for this week.  Found on Facebook by my friend Jim Drummond.

Actually, it doesn't say anything of the kind.  It's a calendar.  All calendars end...that's how the calendar companies stay in business.  In all seriousness, when the calendar we use today, the Gregorian calendar, comes to the end of a cycle, no one worries that the world will end too...they just go buy a new calendar.  The Mayan Long Count calendar is no different - a new long count cycle will begin on Saturday, and life will go on.

Doomsday predictions and fears have been a common theme in humanity's long history.   It is not, by any means, a modern thing.  In fact, the first known "prediction" for the end of the world dates back to 2800 BC!  An Assyrian clay tablet dating to those times was found with the inscription "Our earth is degenerate in these latter days. There are signs that the world is speedily coming to an end. Bribery and corruption are common."  Just in case you thought that bribery and corruption were something invented in the modern era as well...clearly, we've always been good at those things.  Perceived degeneration of morals has long been seen as an indication of the coming end of the world.

There's a long tradition of apocalyptic destruction coming from space as well.  One of the earliest space-related predictions for the end of the world was made in the 1180s, when John of Toledo circulated a letter stating that the coming planetary alignment in Libra on September 23, 1186 would signal the end of the world, and only a very few people would survive.

Comets have long been seen as harbingers of doom.  One of the first comets to be directly associated with the coming end of the world was seen in 1532.  The prediction was made by a Viennese bishop, Frederick Nausea (!), after he heard numerous reports of bizarre occurrences, including bloody crosses being seen in the sky alongside the comet.  One wonders if this is the origin of our use of the word nausea today.

"Astronomical Chart of the path of the Comet of 1532", artist unknown.  From the Gedden Museum.

Sometimes the astronomical predictions get really exciting.  Tomasso Campanella, a Dominican monk, predicted that the Sun would collide with the Earth in 1603.  You'd think we'd have seen that one coming.

Obviously, none of these doomsday predictions came true.  But the long history of man's fascination with the end of the world is, in itself, quite fascinating!  Not being a psychologist, I can't really say why we are so fascinated with the concept of the end of the world.  But I wonder if it doesn't indicate a desire on our part to be involved in something greater than ourselves.  Even if that something gets a little scary at times.

So all in all, Friday should boil down to little more than Mayan New Year.  And you know what New Year's means...it's time for a party!  We're having an End of the World Party at the Virginia Living Museum, and everyone is invited!  We'll be scanning the skies with our telescopes, searching for any killer asteroids (weather and disasters permitting), plus we'll have some fun activities and games going on in the Wason Education Center.  Activities and observing are FREE!  Plus, we'll be having some fun in the cafe, and you can grab a last meal, snack, or even some beer or wine.  In the planetarium, we'll have shows throughout the evening, including Star of Wonder: Mystery of the Christmas Star (6pm), Laser Holidays (7pm), 2012: The End of the World? NOT! (8 & 10pm) and Lasers at the End of the World (9 & 11pm).  Shows are $6 each, or two for $10.  Make it an End of the World Combo: any 2 shows and a $5 cafe gift certificate for $12!  Members always pay half price!  Stick around until midnight and help us end the world with a bang...or ring in Mayan New Year...whichever comes first.

As this will be my last entry of 2012, let me take a moment to wish all of you a wonderful holiday season, a Merry Christmas, and a joyous and blessing-filled 2013.

Carpe noctem!
See you in 2013,
Kelly

Four Small Orbits for the Earth, One Giant Leap Day for Mankind

Happy Leap Day!  It's February 29th, a day that comes only once every four years.  Well, almost once every four years.  Sometimes we skip it.  Do you know the rule for Leap Years?  It gets pretty complicated.  Let's pick it apart, shall we?

Leap Year Rule, Part I: If the year is evenly divisible by four, add one day to the end of February.

Why would we need any kind of rule at all?  Everyone knows that a year is 365 days, right?

Except it's not.

We use a calendar which has 365 days, because that is the number of days it takes the Earth to make one complete trip around the Sun.  But unfortunately, the Earth doesn't quite complete a revolution in 365 days.  In order for the Earth to return to exactly the same spot in its orbit around the Sun, the Earth actually moves for 365 and 1/4 days.  Our calendar ignores this quarter-day, so every 4 years, we need to add a day to our calendar to keep everything lined up correctly.  If we didn't add this day, over time, the extra days would build up, and we'd find ourselves celebrating New Year's in the middle of summer.  So adding a day once every four years helps to keep our calendar days in synch with the seasons as we expect them.

The reason why we need Leap Day.  Credit: Kelly Herbst

Leap Year Rule, Part II: If the year is evenly divisible by four, add one day to the end of February, unless the year is divisible by 100, then don't add a Leap Day.

Okay, so we had a nice simple rule.  Why add this extra bit?  Well, because once again, our math is slightly off.  That extra bit of time it takes for the Earth to truly complete one revolution?  It's not really exactly one quarter of a day.  A year is actually about 365.24 days long...almost one-quarter day but not quite.  So every four years we're adding just a little too much to the calendar.  Over a long period of time, this drift begins to add up again, and your seasons start getting out of synch.  So by the time you've been following the part one rule for about 100 years, you've added about one whole extra day to the calendar that you didn't need.  So skip Leap Day in years that are divisible by 100.

Leap Year Rule, Part III: If the year is evenly divisible by four, add one day to the end of February, unless the year is divisible by 100, then don't add a Leap Day, unless the year is also divisible by 400, then keep the Leap Day.


Okay, now things are just getting silly.  Another adjustment?  Yep, sorry to say it, but 365.24 days isn't the exact time for the Earth to revolve around the Sun once either.  The actual length of a year is really about 365.2425 years.  So if you've been following the part two rule for about 400 years, you've subtracted off one too many leap days and you have to add one back in again to keep the calendar in synch with the seasons.

Notice I said "about 354.2425 years"?  Yes, someday, the leap day rule may grow even more.  The problem here really lies in the fact that we are able to make more and more precise measurements of the actual length of a year.  The basic "once every four years we need an extra day rule" was well-known to the ancient Romans.  In about 45BC, this idea was codified into the Julian calendar, and the concept of the regular Leap Day was first put into practice.  But by 325AD, the Council of Nicaea was already wrestling with the problem that the celebration of Easter was drifting from the season where the church had determined it should be celebrated.  But calendar reform is not easy, and it took another 1300 years before Pope Gregory XIII was able to get the majority of the world to agree to shift to a new calendar, one that included both parts II and III of the leap year rule.  We use this Gregorian calendar today, and even this modern calendar accumulates one day of error in 8000 years.

Pope Gregory XII.  Source: Wikipedia

Will the year 8000AD see another adjustment to our leap year system?  Maybe.  Because something else is happening that we haven't discussed - the length of Earth's year is not constant.  It changes ever so slightly over time.  So by the time we get to 8000AD, we might not need to make any adjustment at all!  Or...we might need to adjust things in the other direction!  But whatever happens, don't worry about it.  Just enjoy this extra day in February - take the opportunity to do something fun!  Subway is giving away free cookies today...sounds like a fun thing to me!

And a special Happy Birthday to my friend Eric, who turns 6 (24) today!  Happy Leap Day everyone!
Until next time,
Carpe noctem!
Kelly