Dr. Van Der Sanden Talks About Bog Bodies

 

 

Since our new special exhibit Mummies of the World has officially opened for all to come and see, we thought it would be a good idea to publish a series of blogs about the different kinds of mummies featured in the exhibit.

Oh yes, not all mummies are the same. In fact, not all are created on purpose! Although the Ancient Egyptians and a few other cultures around the world mummified their dead in preparation for the afterlife, the bog bodies of Northern Europe were not “prepared” at all.

The most famous bog bodies (aka “bog mummies”) have been found in places like Ireland, Denmark and Germany, and were mummified by completely natural processes. Some of them may have been simply buried by family and friends, others may have been executed or even sacrificed to Celtic of Irish Deities,  but all were sunk into the moist, air-tight depths of the local bogs.

The air-tight qualities of the thick, mossy material that make up bogs are part of the reason that the bodies are so well preserved. Without oxygen, bacteria can’t survive to do its dirty business of decomposing dead plant and animal material.

In the cold, acidic, anaerobic environment of a bog, not much other than moss can grow. Sphagnum moss is an important part of the makeup of Northern European bogs. As the moss continues to grow, older layers are buried beneath the surface and die. This dead moss does not decompose in the anaerobic environment of the bog, though. Instead, it is compressed deeper and deeper under the surface of the bog until it becomes peat. During this transformative process, chemicals are released that seem to have a further effect on the preservation of the body. The acidity of these chemicals help to stop the growth of bacteria. Tannins are one type of chemical released during this process. These acids are used in the production of leather (you may have also heard the term thrown around in discussions of wine), and in the bog they may help to preserve the soft tissue.

Bog bodies offer a rare opportunity for researchers too peer into the past and examine the bodies of a culture that did not traditionally preserve the bodies of their dead, and so left relatively small number of well preserved remains to be examined by scientists. 

So when you think of mummies, don’t just think of cultures like the Ancient Egyptians, or even those in South America that artificially mummified their dead. Sometimes nature does all the work. Here at HMNS we have even have mummified dinosaurs on display in our Hall of Paleontology!

Educator How-to: Learn to Draw a Celtic Triquetra

At the Houston Museum of Natural Science, we know that people are as much a part of natural science as rocks and dinosaurs. That’s why we love social studies and maintain exhibits like the John P. McGovern Hall of the Americas and the Hall of Ancient Egypt. We find the development of societies fascinating!

The historical Celts, a diverse group of tribal societies in Iron Age Europe, ranged over a large swath of land reaching as far west as Ireland and the Iberian Peninsula, east to central Anatolia, and north to Scotland. The Celts used a three-cornered symbol, known as the triquetra, to adorn everyday items and important ritual objects. Similar tri-cornered symbols are seen in the artwork of many ancient civilizations. It is speculated that the symbol illustrates the uniting of the past, present, and future or birth, life, death. As Christianity spread through Europe, the triquetra was used to help new converts to understand the concept of the Trinity.

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It is really simple to draw this ancient knot-work symbol. All you need is paper, a compass, an eraser, and some markers.

First, using a compass, draw a circle of at least 3 inches in diameter in the middle of your paper. Make sure to leave room around the circle, as the resulting knot will be slightly larger than the initial circle. Make sure that you do not adjust the compass after the circle is drawn.

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Next, use a pencil to make a point on the circle at the twelve o’clock position. Then, place the point of the compass on this point and use it to make marks where it crosses the circle on each side.   

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Now, place the point of the compass on one of the marks made in the previous step. It doesn’t matter which one. Then, draw a semi-circle within the initial circle. It should start at the twelve o’clock point and end in the lower quarter of the circle. The arc does not need to be continued outside of the circle. Make another arc, identical to the first one. The two arcs should cross at the center point of the circle. If they don’t, check to make sure that the compass setting has not been changed.

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Then, placing the compass point on the lower tailing end of one of the arcs, mark off another tic on the bottom of the circle.celtic5

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Now place the point of the compass on the bottom mark and draw an additional arc from side to side within the circle.

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You will now need to enlarge the diameter of the compass a bit. Place the compass point back onto the marks made in the upper half of the circle. From each point, draw another arc within the circle, and extending a little beyond its border. It is important to make sure the arcs are extend a bit outside of the circle so they’ll meet up when the arcs are all drawn.

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Pick a point where one of the knot strips intersects another, and make it pass over the other, erasing the lines from the underside from within the “over” strip. The next pass for the knot strip, following the same strand, will be to go under the next intersection, so erase appropriately. At this point ,you may erase the initial circle and the arc marks.

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Now your trisquetra is complete! Color it in! See designs like this and others this summer in the Medieval Madness Xplorations Summer Camp.

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Go Stargazing! February Edition

Venus continues to dominate the western sky on February evenings.  Look west-southwest right as night falls for the brightest thing there except for the Moon, which is nearby at the end of the month.  Venus, on its faster orbit, is coming around to our side of the Sun (and will pass us in March).  Therefore Venus is about as bright as it can be this month. 

Saturn is now a late evening object, rising in the east by 9 p.m. now and by 7 p.m. at month’s end.  Early next month, it will be opposite the Sun in the sky and be visible all night long. 

Mars and Jupiter are lost in the Sun’s glare much of this month.  They form a close conjunction on the morning of February 17, but the pair rises right as the twilight begins to brighten the sky that morning.  Mercury joins them later in the month. 

Dazzling Orion rises in the east, reminding us that winter is here.  His belt points up to Aldebaran, the eye of Taurus, the Bull.  The Dog Stars Sirius and Procyon are below Orion in the east.  Sirius is the brightest star we ever see at night.  To Orion’s left as he rises are two stars of similar brightness less than five degrees apart.  These are Castor and Pollux, marking the heads of Gemini, the Twins. 

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Creative Commons License photo credit: Fingerz


Moon Phases in February 2009:

1st Quarter             February 2, 5:12 pm
Full Moon               February 9, 8:49 pm
Last Quarter           February 16, 3:38 pm
New Moon             February 24, 7:35 pm

The Full Moon of February 9 almost enters the Earth’s shadow.  It does enter a region of space called the penumbra, in which the Earth partially blocks the Sun.  This event is thus called a penumbral eclipse.  However, it begins right as the Moon is about to set here in Houston.  What’s more, a penumbral eclipse is only a slight darkening of the Moon, barely noticeable in the darkest skies.  In the morning twilight of February 9, you won’t see much of any difference in the Moon as it sets.

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Creative Commons License photo credit: S1lvers Family


Punxsutawney Phil saw his shadow on Groundhog Day, meaning six more weeks of winter.  What does this have to do with astronomy?  Well, Groundhog Day occurs about halfway between the winter solstice and the vernal (spring) equinox.  It therefore occurs near one of the cross-quarter days, called Imbolc by the Celts.  The other three are at the beginning of May, August, and November, and they represent points halfway between the quarter days, which are the equinoxes and solstices. 

Since we don’t want Phil to see his shadow, we clearly don’t want sunshine on February 2.  If this seems ‘backwards,’ consider that there is another day when we don’t want sunshine or warmth-Christmas. 

Houstonians still fondly recall our Christmas Eve snowstorm of 2004, while a similar snowfall on January 24 would have been much less romantic.  The French have the saying, “Christmas on the balcony, Easter by the fireplace.”  Early pagans considered the winter solstice and Imbolc symbols of winter itself.  If these days were appropriately wintry, with clouds and cold, then it was a sign that all was in order.  Winter, which was happening on time, would end on time.  However, if these days were not appropriately wintry, then something was wrong, and a ‘remedial’ winter would need to occur in springtime.  The traditions of the winter solstice and Imbolc were transferred to Christmas and Groundhog Day, respectively.  Thus, sunny weather (with shadows) is a bad omen on Groundhog Day, while cloudy weather (no shadows) is a good omen. 

A Trick or a Treat?

In less than a week, people all over the country, including right here at our museum, will be celebrating Halloween. Perhaps your workplaces and schools are already festooned with ghosts, skeletons, graveyards, and the like.  If you stop and think about it, you may wonder just how it is that we came to celebrate by trying to disguise ourselves or by trying to frighten people.  Is this a trick or a treat?

Picket fence and yellow trees
Creative Commons License photo credit: joiseyshowaa

The short answer as to why we celebrate this time of year with images of death is that we are in the middle of autumn, the season when nature itself is dying.  To fully understand why we celebrate Halloween when we do, we must fully understand the seasons.

Earth orbits the Sun with its axis pointed at the North Star, Polaris. As a result, its axis is tilted by about 23.5 degrees with respect to its orbital plane.  This tilt, combined with Earth’s revolution around the Sun, causes the seasons.  If the North Pole leans towards the Sun, the Sun is higher in our sky and we get more direct sunlight.  Also, daytime is longer than nighttime.  As the North Pole begins to tilt away fron the Sun, the Sun appears lower and lower across the sky, and daytime gets shorter and shorter.  Eventually, the slanted-in solar rays and short days bring about winter.  Very cold air masses form in the darkened Arctic and begin to move south, some of which can even reach Houston.

Keep in mind that the Earth’s axis does not tilt back and forth; it points at Polaris the whole time.  In June, the North Pole is leaning towards the Sun, but by December, the Earth’s motion has carried it to the other side of the Sun.  The North Pole, still tilting the same way, now leans away from the Sun.

A common misconception is that the Earth is closer to the Sun in summer and more distant in winter, and that is what causes our seasons.  In fact, Earth’s perihelion (closest approach to the Sun) occurs just after the new year (January 1-4), while aphelion (greatest distance from the Sun) occurs around the 4th of July.  Earth’s orbit is an ellipse, but the Earth-Sun distance does not change by enough to affect our seasons.

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Creative Commons License photo credit: shioshvili

In the cycle of seasons, there are four points of note.  At the March equinox, neither pole is tilted toward the Sun and the Sun is directly overhead at the equator.  The is the vernal (spring) equinox for us and the autumnal (fall) equinox for folks south of the equator.  At the June solstice, the North Pole is tilted as much as possible towards the Sun, and the Sun is overhead at 23.5 degrees North (the Tropic of Cancer).  This is the summer solstice for us and the winter solstice in the Southern Hemisphere.  At the September equinox, once again neither pole tilts toward the Sun, and the Sun is again overhead at the equator.  This is our fall equinox and their spring equinox.  At the December solstice, the North Pole is tilted as much as possible away from the Sun, and the Sun is overhead at 23.5 degrees South (the Tropic of Capricorn).  This is the winter solstice for us and the summer solstice below the equator. 

We generally think of these points as the beginning of spring, summer, fall, and winter, but it doesn’t have to be that way.  After all, nothing magically happens with our weather on these dates.  We could just as well consider these points the midpoints of each season.  In that case, the seasons would begin and end at points roughly halfway between the equinoxes and solstices, in early February, May, August, and November.  If the equinoxes and solstices are ‘quarter days,’ the points halfway between them become the ‘cross-quarter days.’

The ancient Celts of Europe appear to have divided their year in precisely that way.  Gauls living in what is now France used a calendar of twelve lunar months with a 13th month added every 2.5 years (similar to the Hebrew calendar today).  Their two most significant months were Gamonios (lunar month corresponding to April/May ), which began the summer half of the year, and Samonios (lunar month corresponding to October/November) which began the winter half of the year.  Julius Caesar noted that daytime followed nighttime in Celtic days.  By extension, the dark (winter) half of the Celtic year preceded the light (summer) half, making Samonios the start of their new year.

The Celts in the British Isles (Irish and Scots) also had festivals aligned with the cross-quarter days.  In early February was Imbolc (or St. Brigid’s day).  Weather predicting traditions of this day are preserved in our current Groundhog Day.  Traditional May Day celebrations are similar to those of the Celtic BeltaneLughnasadh, in early August, marked the start of the harvest. 

'' The Sentiment of Light''
Creative Commons License photo credit: jdl_deleon

The most important, though, was Samhain (pronounced ’sah win’, not ‘Sam Hane’, due to rules of Gaelic spelling), in early November.  This three-day festival marked the beginning of the winter half of the year and the start of the whole year, like Gaulish Samonios.  It was the close of the harvest opened at Lughnasagh, and the time for culling excess livestock.  At this time, the veil between the living and the world of the dead was considered thinner than usual, and people looked forward to meeting and communing with ancestors and relatives who had died.  A ‘dumb supper‘ was set aside for departed relatives.  To scare away unwanted spirits, people dressed in frightening garb.  Note that these spirits were considered unpredictable and possibly mischievous because they were not the familiar ancestors–not because they were particularly evil.  Divination was also practiced at this time, as people sought to predict whom they would marry or how many children they would have. 

Doing the math, you’ve probably figured out that Halloween is not quite halfway from the equinox (September 22) to the solstice (December 21).  But remember, the Celts used a lunar calendar.  They celebrated their festivals on a certain phase of the Moon, possibly full moon, occurring nearest the cross-quarter day.  Upon the adoption of the Julian calendar, which was not strictly lunar, the festivals were moved to the beginning of February, May, August, and November, although this meant they were no longer exactly on the cross-quarter days. 

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Creative Commons License photo credit:
The Wandering Angel

In the eighth century AD, Pope Gregory III moved the church’s commemoration of the souls in heaven (All Saints’ Day) from May 13 to November 1.  Another name for All Saints’ Day is All Hallows Day.  (’Hallow’ is an older term for ’sanctify’ or ‘make holy.’  Think of ‘…hallowed be thy name’ from the Lord’s Prayer).  The next day became All Souls’ Day.  The day before All Hallows Day or All Saints’ Day is All Hallows Eve, or Halloween.  The traditions of Samhain, with its similar focus on honoring the dearly departed, were a natural fit for All Hallows Day and All Hallows Eve.

Halloween, then, is ultimately just one expression of the human need to come to terms with death as a natural occurence and to honor those who have gone before.  In the season of the fall of the leaf, with the Sun taking a slightly lower path across the sky each day, the natural world is going through its own ‘death,’ providing a perfect context for our own activities.  We can therefore think of Halloween itself as a treat, not a trick.

I wish everyone a Happy Halloween, with many more treats than tricks.