Moments frozen in time.



Archaeologists study past human behavior. We do so using material evidence left behind that tells us of that behavior. Artifacts and architecture retrieved from the past may be esthetically pleasing, but ultimately archaeologists are most interested in the people who made or built these things to answer questions such as who, what, when, where, and why?

Occasionally, we encounter artifact assemblages or architectural features that are incredibly well preserved. They appear to be almost pristine, as if their owner, or maker, just briefly stepped away and is about to return any minute now. I would call these discoveries and the sentiment they evoke “moments frozen in time.” Here are a few examples.

What do a Roman ointment jar, Roman legionnaires’ letters written on thin wooden tablets, a Maya priest’s lunar calculations made on a whitewashed wall and a Maya altar discovered in a cave have to do with each other? Simple: they all represent moments frozen in time.

Some two millennia ago, a well-off Roman closed the lid on a jar containing a skin cream. It was not until July 28, 2003 that archaeologists opened it. Humble in its appearance, this small tin container had been unearthed during excavations at a Roman temple complex in Southwark, London. It showed very little wear and tear, making it a very remarkable find. Better yet, inside the container the scientists found what appeared to be cream, complete with fingerprints. We will never know how the jar got discarded, nor what happened to its owner, but it represents a moment frozen in time.

A few hundred miles to the North of Londinium, as London was known in Roman times, soldiers manning Hadrian’s Wall did what most soldiers do during peacetime: they wrote letters about very mundane things. The Wall, which had been built on the orders of Emperor Hadrian after a visit to the region in 122 AD, consisted of a 73-mile long stretch of mile castles and observation turrets, marked the northernmost borders of the Roman Empire.


Location of Hadrian’s Wall and the Antonine Wall. (By Hadrians_Wall_map.png: Created by NormanEinstein, September 20, 2005. Derivative work: Talifero (talk) – Hadrians_Wall_map.png, CC BY-SA 3.0,

While for a brief period of 20 years, this distinction went to the Antonine Wall in Scotland, Hadrian’s Wall marked the northern border of the Roman Empire until 410 AD.
Starting in 1973, archaeologists working at Vindolanda, a major military garrison associated with the wall, have been unearthing thin, postcard-sized wooden tablets carrying messages written in ink. These messages were penned by soldiers, their families, and even slaves. Among these were an invitation to a birthday party held in about 100 AD, (perhaps the oldest surviving document written in Latin by a woman)


(Vindolanda tablet 291. Letter from Claudia Severa to Sulpicia Lepidina.).


Another missive deals with socks, shoes and underwear, all important creature comfort items in the chilly climes of northern Britain.

moments3Vindolanda tablet 346, containing a message about “socks, sandals and underpants.”

These brief messages give us a glimpse into daily life of regular human beings. Scholars who have looked at the hundreds of Vindolanda tablets recognize the quirks of individual handwriting. It takes us one a step closer to the person who one day sat down and wrote a birthday invite, or alerted a friend about a shipment of warm socks and underwear. Fleeting moments, to be sure, but also moments frozen in time.

Roughly at the same time as British archaeologists were discovering the first wooden tablets at Vindolanda, looters were busy pilfering the Maya site of Xultun, in northern Guatemala. Sadly, they did extensive damage to the site, including to a small corbel-vaulted structure, known as Structure 10K-2. It was not until 2008 that professional archaeologists got an inkling of what was hidden inside this structure: three of the structure’s interior walls (west, north, and east), as well as its vaulted ceiling, were once covered by paintings.

On one of the walls, it appears that a layer of whitewash had been applied, covering an existing painting. The wall had been resurfaced to allow jotting down lunar cycle calculations. Archaeologists now think that Structure 10K-2 may very well represent a workspace of a Maya scribe whose job it was to be official record keeper of a Maya community. Imagine the day this individual walked in, covered the wall with an extra coating of white paint, and started making calendrical calculations. Once these were done, the individual walked away, and the wall remained unchanged for more than a millennium. The spontaneity with which the wall was repurposed contrasts with what must have been the initial function of that room. This impulsive act was preserved for posterity; it represents another moment frozen in time.

Recently, archaeologists working in the cave systems of northern Yucatan discovered an extraordinarily well preserved Maya altar. On December 2, 2016, the Instituto Nacional de Antropología y Historia announced the discoveries made by the Proyecto Gran Acuífero Maya. In one of the caves, located in the state of Quintana Roo, archaeologists found walls and pathways. They also encountered a “Maya altar in an unusual state of preservation.”

momenst4Altar discovered in a cave in the state of Quintana Roo, Mexico. Notice the stalagmite fragment on top. (Image courtesy of Gran Acuífero Maya. Photo: Leyla Ortega)

The altar has been dated to the early Postclassic period (900 – 1200 AD). It is still covered with stucco, decorated with human, animal and abstract shapes. Associated with the altar was a large fragment of a stalagmite (said to have been linked to fertility by the ancient Maya).

The ointment jar, the wooden tablets, the calculations made on a wall and the altar found in a cave are all fleeting reminders of what people once did in the past. Their delicate nature makes the survival of these items all the more remarkable.

I often wonder what future archaeologists might discover about our own society that would fall in the same category of a “moment frozen in time.” Any ideas?

What the Heck is a Tues, Wed, Thurs, or Fri?

Earth Mars and Moon to scale
Creative Commons License photo credit: Bluedharma

We measure time based on motions in space.  The Earth rotates on its axis once a day.  The Moon orbits the Earth about once a month.  The Earth orbits the Sun once a year.  That leaves the week as the only aspect of our calendar not directly tied to the Earth, Moon, or Sun. The week, as it turns out, is based on the other planets of our solar system–at least, those easily visible to the naked eye.

Early astronomers were able to distinguish planets from stars because planets seem to move against the starry background.  The stars are always rising, moving across the sky, and setting due to Earth’s rotation.  They seem to form the same patterns all the time; we never see them move relative to each other.  (In fact the stars do have proper motion, but we don’t notice it over a time frame as short as a human life or even over several generations).  Anything shifting noticeably over several days was a ‘wandering star’, or planet.  Early astronomers identified seven ‘wanderers’: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn, and the Greeks placed them in just that order.

This order, of course, is wrong; it makes the basic error of putting the Sun in orbit around the Earth when in fact the Earth orbits the Sun.  Fixing this error by replacing the Sun with the Earth, however, makes the order from Mercury to Saturn correct.  That’s because the order is based on something directly observable–the planets seem to move among the background stars at different rates.  Ancient observers saw the Moon reappear near the same set of stars once a month.  Saturn, on the other hand, takes 29.5 years to reappear in the same part of the sky. 

The different speeds are even more apparent when two or more planets are near one another in the sky (an alignment called conjunction).  Any planet in conjunction with Saturn catches up to Saturn and then passes it.  It’s never the other way around.  Any planet (other than Saturn) in conjunction with Jupiter catches and passes Jupiter, never the other way around.  For early astronomers, slowness was associated with distance.  By carefully observing the planets’ motions and planetary conjunctions, early observers could place them in order.

Ancient Roman writer Dio Cassius was among the first to explain how the order of the planets from slowest to fastest (and thus from outside in) generated the week.  The system involves the 24-hour day and an astrological belief that each hour was ‘ruled’ by a planet following the order above, such that Saturn’s hour was followed by Jupiter’s, then Mars’, then the Sun’s, and so on.  Further, whichever planet governed the first hour of each day governed that whole day.  On Saturn’s day, then, the hours were as follows:

1) Saturn  2) Jupiter  3) Mars  4) Sun  5) Venus  6) Mercury  7) Moon 8. Saturn  9) Jupiter  10) Mars  11) Sun  12) Venus  13) Mercury  14) Moon  15) Saturn  16) Jupiter  17) Mars  18) Sun  19) Venus  20) Mercury  21) Moon  22) Saturn  23) Jupiter  24) Mars  25) Sun

Since there are 24 hours in a day, the 25th hour of Saturn’s day is the first hour of the next day.  Therefore, Saturn-day is followed by Sun-day.  Redo the list of hours, this time starting with the Sun, such that hours 1, 8, 15, and 22 are the Sun’s.  Hour 25 becomes the Moon’s hour, which means the Sun-day is followed by Moon-day.  Repeat the list with the Moon in first position, and eventually the following order of days emerges:

1) Saturn-day  2) Sun-day  3) Moon-day  4) Mars-day  5) Mercury-day  6) Jupiter day  7) Venus-day

If Venus governs the first hour, Saturn governs the 25th, and the cycle begins again.  A full table of the hours and days is here (this list also has the name of the days in 30 different languages).

You probably recognize Saturday, Sunday, and Monday in this list.  To get the other English day names from this list, we have to translate by replacing the planet names, which are names of Roman deities, with roughly equivalent Germanic deities.  Languages derived directly from Latin have preserved the Roman gods’ (thus the planets’) names more faithfully.  For example, you can recognize Latin luna (the Moon) in French lundi, Spanish lunes, and Italian lunedì.

Apollo Belvedere
Creative Commons License photo credit: Alun Salt

Similarly, Mars-day is martes in Spanish, mardi in french, and martedì in Italian.  Germanic tribes, however, replaced the Roman war god Mars with their own warlike god Tiw (or Tyr for the Norse).  Thus, Mars’ day became Tiw’s day or Tuesday.

‘Mercury-day’ is recognizable in French mercredi, Spanish miércoles, and Italian mercoledì.  The Germanic pantheon had no messenger god that corresponded well to the Roman Mercury, so they equated him with Woden (Norse Odin).  Both Woden and Mercury were gods who escorted the recently deceased to the underworld.  Also, Woden became the fastest god when he rode his eight-legged horse Sleipnir.

Creative Commons License photo credit: Pro-Zak

Jupiter’s original name in Latin was Jovis (‘Jove’ to English writers); the name Jupiter is a contraction of Jovis pater (‘father Jove’).  ‘Jove-day’ is recognizable in French jeudi, Spanish jueves, and Italian giovedì.   Although Jupiter, like the Greek Zeus, was the king of all the gods, his actual domain was the weather.  In particular, he was the god who caused storms and struck people with lightning.  Thus Germanic tribes assigned his day to Thor, their god of thunder.  Thor’s day is Thursday.

‘Venus-day’ is still recognizeable in French vendredi, Spanish viernes, and Italian venerdì.  Germanic tribes replaced Venus’s name with that of Frigg, the wife of Woden who was associated with married women and whom they called upon to help in giving birth.  Frigg-day is Friday.

As the Germanic tribes had no one in their pantheon who even roughly corresponded to Saturn, Saturn’s name remains in Saturday.  Ironically, the Latin-based languages have lost ‘Saturn-day’ as the day’s name.  Spanish sábado and Italian sabato derive from the word ‘sabbath’ (as does French samedi, through a more complex etymology).  This is due to the influence of the Catholic Church, which was loath to name the days of the week after pagan gods, and sought to replace the planetary names. 

The Church designated Sunday ‘Lord’s Day’ (dies dominicus), called Saturday the sabbath (sabbatum), and numbered the weekdays from 2 to 6.  Except in Portugal, however, the numbered weekdays never replaced the planetary days in popular usage.  Everyday people in southern Europe did adopt the Church’s terms for the weekend days.  Northern Europe, largely outside the influence of the Catholic Church, was less affected by this; we retain ‘Saturday’ and ‘Sunday’ in English as a result.

In November and December 2008, you can make for yourself some of the observations that helped astronomers of antiquity imagine the solar system.  The two brightest points of light in the southwest tonight are Venus and Jupiter.  They outshine all stars we ever see at night and are visible even in twilight.  But don’t wait too late; you’ll need to look in the hours right after sundown before the two planets set.  Venus, lower to the horizon, is the brighter of the two.  Its closeness to us and the clouds that cover the whole surface and reflect most sunlight back into space cause Venus to outshine the much larger Jupiter.

Watch as Venus gets closer and closer to Jupiter each night this month.  This is exactly how ancient astronomers could tell that Venus and Jupiter were not stars.  On November 30 and December 1, watch as Venus passes 2 degrees ‘under’ Jupiter.  (The crescent Moon also passes by on these nights).  Imagine ancient Greek astronomers concluding that Venus is closer because it is faster.  Keep watching each night in December as Venus pulls away from Jupiter, getting higher in the dusk sky while Jupiter sinks into the Sun’s glare by early January.  Early astronomers would have seen this as the Sun catching up to Jupiter while Venus pulls away; observations like this account for the Sun’s position in the ancient order of ‘planets’.  Of course, we now know better–the Sun’s apparent motion is really ours.  Earth is going around the far side of the Sun from Jupiter’s position, putting Jupiter behind the Sun as the New Year opens. 

Venus remains an evening star until March 2009.  Compare Venus to the stars around it, and you’ll see it slow down and then move ‘backwards’ towards the Sun’s position each night in March.  That’s because Venus will have come around to our side of the Sun, and will be passing us up on its faster orbit. 

Should you make any of these observations on a Thursday or Friday, you can reflect on why those days have those names.