Stonehenge, one of the world's
oldest structures. Its foundations predate
the Great Pyramids. It is one of mankind's
most ancient mysteries. Why is it here?
Is it a temple? A burial ground?
A place for sacrifice? Or could the mystery of
Stonehenge be revealed in its builders' desire to explore
the unknown heavens and touch the universe?
Using the cutting-edge computer-generated imagery
that takes us into deep space, we'll also go inside a virtual
Stonehenge to see what the ancients saw and push
this prehistoric marvel to give up its age-old secrets.
Ancient mysteries shrouded in the shadows of time...
Now can they finally be solved by looking to the heavens?
The truth is up there, hidden among the stars in
a place we call the universe.
Sync and corrections by n17t01 www.addic7ed.com
The mysterious circle of stones called Stonehenge sits on
a southern English plain inside an earthen bank
5,000 years old. It was built over 15 centuries,
begun by Stone Age farmers and herders, later completed
by groups of successor peoples with sophisticated
engineering skills. What drove them to build it?
What is Stonehenge?
People have said that it's
a giant temple, a wonderful
monument sitting out in
the Salisbury plain, where
thousands of people could've
come thousands of years ago.
To worship what?
Gods?
We have no written records. We take what we can from
what we see and attempt to find out what it is.
What we see are the ruins of what was once
a complex array. Could this structure made
of earthly rock actually have been devoted to what takes place in the sky?
Watching the bright Sun come up every day,
the Moon come up and change its shape throughout
the weeks and the months, must have been quite a show.
Was this the Hubble Telescope of its time?
The first clue to the mystery may come from the Sun.
Every June, huge crowds gather at Stonehenge in a strange
dawn ritual. It's the first day of summer,
the solstice, longest day of the year.
The people stare intently at a giant boulder called
The Heel Stone.
What is remarkable about
the construction of Stonehenge
is that on the first day
of summer, if you stand at
the center of the monument
and orient yourself toward
The Heel Stone, then as the Sun rises, you'll see, essentially,
the Sun come up just over The Heel Stone.
The precision to which this occurs year after
year seems miraculous.
Is it just a coincidence, or did the ancient builders put
the monstrous heel stone in just the right place to mark this
day's sunrise every year?
It's outside of the ring. It's over 200 feet outside
of the ring. It is 16 feet tall.
It's probably got another four feet in the ground
just to keep it stable, and it weighs 35 tons.
Was Stonehenge a Sun temple with its focus at
The Heel Stone? Do other stones point to
the Sun as well? The ruined monument we see
today is incomplete, so the answers may lie in
just how the giant stones were originally arranged.
The main ring was a series of vertical slabs topped
with heavy crosspieces. These lintels, as well as
the uprights, were made of sarsen stone, a type of
sandstone common to the area. The Sarsen Circle is
180 feet across, 30 stones.
Average weight can be anywhere
between 20 and 40 tons.
This is as large as a fully
loaded cement truck.
This construction task boggles the mind even today.
Inside the sarsen ring is a horseshoe arrangement
of heavy stone arches, each piece weighing up to 50 tons.
They're known by a deceptively forbidding name, The Trilithons.
"Trilithon" just means "three stones," three stones
in this configuration. So two giant stones have
been stuck into the ground with another giant stone
then carefully placed on top.
To work out the link between the stones and
the Sun's changing path through the sky, you would need
to visit Stonehenge every day for a year and place cameras
in dozens of locations, but now there's a better
way to look at Stonehenge from every angle through
the power of state-of-the-art computer graphics.
So in the simulation, we're present-day summer
solstice sunrise. We're camming out, coming up
over the monument, taking at look at its
present state, advancing the Sun as well, shadows come
across the surface, and looks beautiful.
Professor John Filwalk heads up IDIA Lab at
Indiana's Ball State University. It was started as part of
a $40 million project to use computers to visualize
what our eyes cannot. Massive processing power
immerses us in the ancient monument.
To decipher the mysteries of the silent stones.
Coming to the Sarsen Ring,
and we can take a look at the *** the back, the main one.
Through the needle there.
Spin around so we can see the features out there.
Using exact measurements of the stones
taken by archaeologists, the computer's camera can
move around a precisely reconstructed virtual
- Stonehenge. - The simulation is as
accurate as can be.
We have an accurate model,
it's positioned accurately,
and the data is also accurate.
So what you're observing
is precise.
Astronomical data compiled by NASA adds
the positions of everything in the sky seen from the stones,
just as if you were standing there.
And by typing in a date and time of day,
we board an electronic time machine that carries us
to any moment in the past, present, or future.
Watching the sunrise position change from month
- to month is effortless. - At this point, let's advance
one month and see what happens. You can see the Sun roughly
- framed by the sarsens there. - If we place the
computer's camera in the center of Stonehenge,
one thing becomes immediately clear.
Your eyes are drawn to the horizon.
Modern man pays little attention to the horizon.
In our cities, it all but disappears, but for ancient
astronomers tracking the Sun, the horizon was a key
- reference point. - If you want to do
astronomy simply, it's really hard to find things in
the middle of the sky, to accurately locate them
when they're directly overhead. But the horizon's a great
place to try and get an accurate measurement of
how things are changing on the sky.
Ancient astronomers
could see that the Sun
rises and sets at different
places on the horizon
during the year.
Because the Earth's axis is tilted, the northern
hemisphere leans away from the sun in winter,
making the sunrise seen from Stonehenge farther south.
In the summer, the tilt is toward the sun, making
the sunrise farther north.
When it rises on the first day of summer,
the Sun is as far north as it ever gets.
Its position, in fact, may have been so important
at Stonehenge, the central axis of the entire site points
directly at it.
But other stones mark the Sun too.
Take, for instance, the massive trilithons.
And each one of those appears to be a site for
an event on the horizon, so for example, I can turn
to one of the trilithons on the sunset of the first
day of summer and watch the Sun set right through the middle,
and the sunlight will come through like a dagger,
right into the heart of the monument, right to where
- I'm standing. - But the summer
sunrise over the heel stone has always seemed the most
important marker. It's in line with the
ceremonial approach called "The Avenue."
The crowds face northeast, looking down The Avenue,
to witness the event each year. But new evidence now suggests
that the true main event at Stonehenge plays out in
a totally different direction in a completely
different month.
For thousands of years, the monument we know as
Stonehenge has defied definition, but today, many
believe it was an early astronomers' site.
Was this a prehistoric observatory with a spiritual
connection to the cycles of the universe?
Exactly what was it its builder saw?
The annual arrival of the crowds celebrating sunrise
in the northeast on summer's first day support the notion
that this was the main event here.
But new evidence turns this theory upside down.
It suggests that astronomer priests conducted their most
sacred rites in the other direction.
A high-tech laser scan in 2011 revealed something
totally new about the main Sarsen Circle.
The sarsens seem to
have been very, very
carefully worked to look
their most beautiful on that
approach from the northeast
and as you go into the monument,
not looking from
the other direction.
But what happens as we do look in
that other direction? The Sun is behind us.
The stones cast their shadows ahead.
Were the Stonehenge builders Sun worshipers who warned us,
"Look away from the powerful God"?
Or could it be that the crowd is not only facing the wrong
way, they are here on the wrong day?
Happy solstice!
If we spin forward in time, half a year of
sunrises and sunsets have gone by, and we reach the moment
when the Sun again appears directly in front of us.
It happens in December on the first day of winter,
when we see not the sunrise, but the sunset.
Only one leg of the largest trilithon still stands,
but in antiquity, it fully framed the breathtaking event.
Was the brilliant winter sunset an object of special worship?
If you walk up to a church, you don't get into the church
and then turn round to see the altar behind you.
The sacred stuff is ahead of you, and by that same
argument, you might expect that the sacred stuff at Stonehenge
is going to be ahead of you, to the southwest.
The new discovery upends our assumptions.
If winter sunset was most important, what other secrets of
the universe are hidden within Stonehenge?
For answers, we must push past the stones pointing to
the sunrises and sunsets that have dominated
observations here. Outside the main Sarsen Circle
were four station stones laid out in a rectangle.
Their positions strongly suggest they were meant as
sight line markers to something. But what?
If you actually look at the sides of that rectangle,
they just miss the stones of the sarsen monument.
Now, only two of these station stones are left now, but if you
had all four of them and you looked along one side,
you'd have just seen one corner from the other.
To solve the mystery of the station stones,
we return to the computer lab. We set up the virtual camera
behind one stone and aim at another across the long side of
the station stone rectangle. We turn day into night,
and suddenly, we see the Moon. As it sets just behind
the distant stone, the secret begins to reveal itself.
The station stones may point to the strange travels of the Moon.
In any given month, you'll see the Moon do what the Sun does in a year.
It goes to the north and goes to the south.
The Moon itself does not travel back and forth
across the horizon. What we observe is the travel
of the places where the Moon rises and sets every day.
One back-and-forth cycle takes place every month.
With the station stones pointing to lunar positions
and other stones aimed at the Sun, some researchers
and scientists now believe Stonehenge was designed for a dual purpose.
Right from the beginning,
it was a lunisolar observatory or temple or a monument
to track the Sun and the Moon positions on the horizon.
But Moon tracking is far more difficult than
watching the Sun. How could Stonehenge's
astronomers have understood the complex cycles of the Moon?
Even today's astronomers have trouble visualizing how lunar
motions in space translate into the Moon's march across
the horizon as it rises and sets on Earth.
Think of yourself in a rocket ship out in space,
looking at the Earth and Moon.
We know the earth is rotating on a tilted axis, but at
the same time, the Moon revolves around the Earth
in an orbit that has a tilt of its own.
But to understand how the Moon looks to us from Earth's
surface, I actually like to turn the picture around,
with the Earth on its side and the Moon at its southernmost
point on its tilted orbit. If we zoom into Earth's surface
and look at the horizon, we can see why the Moon
would appear to be rising in the east, but also, for now,
- off to the south to some degree. - Seeing the Moon in
the southeast, the Stonehenge astronomers would next have
watched for it to reach the north end of the horizon.
The Moon takes about a month to go around the Earth,
so in half that time, about two weeks, the Moon
is at the other side of its orbit.
Now, if we go back out into space, it looks like this,
but to see how it looks from Earth's surface,
we have to swing our rocket ship all the way
around to the other side of the planet.
When we do that, we can see the Moon rising in the east
again, but now it's off to the north by some amount
- instead of to the south. - But in aiming their
stones, the builders of Stonehenge may have also
discovered a subtle secret in the range of the Moon's motion.
The remarkable thing is,
over a period of about
18.61 years, this range
actually changes,
so after about nine years,
it'll decrease a bit,
and then in another nine years,
it'll go back to what it
was before.
So the range of lunar risings is actually changing,
like an accordion sliding back and forth over time,
- with a very well-defined cycle. - Over the course of
its monthly swings, the Moon will reach two extreme
north/south positions in its narrow range and a different
pair in its wide range, four extreme positions in all,
and these are the targets at which Stonehenge's
builders apparently pointed their stones.
The lunar connection showed up in 1961,
when Boston University astronomer Gerald Hawkins
did the first computer calculations of sight lines
at Stonehenge. His findings turned
the ancient ruin into a symbol of mankind's quest to connect
to the universe. Hawkins's conclusions
remain controversial, but many scientists still
respect the accuracy of his work.
I don't think anybody doubts the integrity of
his surveying work and his calculations, and certainly
some of that was duplicated, again, not just by others
but by Hawkins himself.
But could a culture without writing, a people
with only oral traditions, have built up the knowledge
to develop such a keen understanding of the moon
and its motions?
It really is an issue of how long that cycle is.
A cycle that's, say, around
18 years long still is not
so long that it couldn't be
passed on orally from
generation to generation.
The 18.61 years in the Moon's cycle may have
figured in a bizarre numerical code that remains one of
Stonehenge's most enduring mysteries.
It is only one of many on our journey to uncover
Stonehenge's true purpose, like the mystery of
the missing rocks, holes in the ground where
stones have disappeared.
We are separated from the builders of Stonehenge
by 5,000 years or more. How can we possibly
understand what they really meant to do,
so long before modern science began revealing the nature
of the universe? The achievement of the ancient
Britons is awesome. But is there enough left
of Stonehenge to tell us the whole story?
What we see of Stonehenge
is just half, or less,
of what Stonehenge really
once was.
Fortunately, Stonehenge hides some of
its greatest mysteries underground, where signs of
- its many missing stones survive. - There are marks there
of things that are no longer there!
We have to speculate. So what you can do is,
you can scrape off the surface to get to the chalk bedrock.
To set these stones into the landscape at Stonehenge
required making a socket down into the chalk to keep these
giant big stones steady. Those sockets are still there.
While some sockets held the big rocks, others
held wooden poles, and there are hundreds of them.
Were these astronomical markers? Along with the stones that
still remain, they would have represented the advanced
technology of their time.
In the California desert, advanced technology of our
own time may well become a puzzle for the future.
5,000 years from now, if all other clues have
disappeared, what might people think of this?
Wow, look at that thing. It's amazing.
What is that?
I would imagine a future archaeoastronomer would
fairly quickly assume it's some sort of ceremonial site.
They would see a monumental metal structure.
Maybe it functioned as some sort of sundial, maybe a place
of gathering since there's no other habitation in the area.
All I can think of is "Look where I am standing".
I'm standing in a huge desert,
I've got a horizon 360 degrees around.
It just feels like it's a monument to the sky.
Because that is where my eyes are concentrating.
It's the huge sky that I'm seeing above me.
Modern astronomers, of course, can identify
- it instantly. - This is really
state-of-the-art. 25-meter, 82-foot-across,
- dish-shaped radio telescope. - This modern
observatory conceals a clue about the mysterious holes in
the chalk beneath the turf at Stonehenge.
In radio astronomy, scientists constantly
adjust their telescopes by sighting distant,
ultra-bright galactic cores called quasars to calibrate
their readings. Did the Stonehengers go through
- a similar tweaking process? - There are a number of
holes that have been dug into the gap in the ditch
in the bank that surrounds Stonehenge.
The holes are among many that held wooden posts,
easier to move than the giant stones.
What's interesting is that they're on that main
alignment that we know is critical to Stonehenge,
because it's the rising of the summer solstice Sun.
It's the setting of the winter solstice Sun.
We've got this beautiful alignment.
So what are these holes? I gotta wonder if perhaps
this was fine-tuning the positioning of markers
inside and outside the monument.
But four holes hidden beneath the turf near
the heel stone may have aimed not for the Sun, but the Moon.
They show how Stonehengers might have tried to find a place
for a wooden post that would point to the moon when it
rose at the farthest point north it ever reached on
the horizon. At IDIA lab, computer experts
dial in the coordinates for their virtual Stonehenge to
show how the ancient observatory may have been calibrated.
The ancient astronomers knew, generally, the most
northern position of the moonrise, but they needed
- some means of fine-tuning that. - By placing wooden
posts in the four poles, Stonehengers may have expected
one of them to be close to the most northern moonrise.
Virtual Stonehenge computes the Moon's position and reveals
- the secret. - At the fourth hole from
the position of the Sarsen Circle center, we actually
do see a precise alignment.
Who were these people apparently so intent on
tracking the Sun and Moon?
What we're seeing here is the transition from
the Old Stone Age to the New Stone Age, and the essential
development of the New Stone Age was human beings domesticating themselves.
They were staying in one place, and they were starting to farm.
These semi-nomadic farmers and herders were
the first to start building at Stonehenge.
They dug the circular ditch and bank around 3,000 BC,
perhaps even earlier. An opening in the northeast
faced the summer sunrise. Over the next 1,500 years,
successor tribes added the big stones, arranging
and rearranging them into the array whose ruins
remain today.
If astronomical alignments were in fact built into
Stonehenge, why was tracking the Sun and Moon important?
So many other cultures worshiped the Sun and
the Moon as gods, so it's not a huge leap to then assume
that the people of Stonehenge were also worshiping the Sun
and the Moon as gods.
Early man watched the Sun and Moon to keep time
for thousands of years before Stonehenge, but here,
the counting of the days and years may have been
- an ancient sacrament. - The sky was the first
clock, but in many ways, Stonehenge and the monuments
like it were a way of creating a culture that ritualized time
in some sense.
Over 15 centuries, Stonehenge's builders dug holes,
hauled stones, shifted them around, added some,
subtracted others. Was this the realm of ancient
astronomers? Or was it the lair of a secret
cult in a long lost religion with its faith founded in science?
The enduring mystery of Stonehenge may rest not with its massive
rocks but in the cosmic patterns of the universe.
Sight lines between the stones align so well to the Sun
and Moon, it seems like an ancient observatory,
but at a time when human cultures were dominated by
strange gods and superstitions, did Stonehenge's farmers
and herders achieve some of mankind's first
scientific discoveries?
Agriculture was a technology,
but it couldn't be separated
from the sense of the mythic,
of the sense of the religious,
the sense of that there were
sacred powers being invoked
every time you planted
seeds in the ground.
So the idea that all that was happening here was
religion is a mistake, just like saying all that
was happening there was some kind of proto-science
is also a mistake. You couldn't separate them
out for these cultures.
Without written records, the stones are our
only evidence of the monument's connection to the universe.
Today we think of astronomers as scientists, precision
observers who attack the mysteries of space
with precision instruments. Did they inherit the legacy
left by the ancient astronomers and their stones?
All of these are actually
precision-built for their
technology 5,000 years ago.
That's the reason why some of
them are still standing today.
They were that well
put together.
But just how precise was this precision-built
monument? The Sun and Moon sight lines
among Stonehenge's rocks are accurate to about one degree.
There's a simple trick
we astronomers use for estimating on degree in the sky.
If you hold out your pinkie finger at arm's length
and look at how wide it appears,
that's about one degree.
Now, the Sun and the Moon are each about half a degree in size, so,
your pinkie finger is about twice the width of the Sun or the Moon.
In today's world,
what we call precision is much more demanding.
A degree 5,000 years ago
was probably good enough
for what they were trying to do.
These days, we talk about locating things in the sky
to accuracies of fractions of an arc second, and an arc
second is a few thousandths of a degree.
But at Stonehenge, was one degree enough?
Thousands of pilgrims each year will swear that the
sun rises directly above the heel stone, but one-degree
accuracy gives them some wiggle room.
As the virtual Stonehenge demonstrates, if the Sun and
the heel stone don't quite line up, a simple step to
one side is all it takes to make it good enough.
To see the Sun rising
from Stonehenge over
the heel stone today,
you just go to the center
of the monument and wait
for the Sun to come up,
and of course, it'll do that.
And if you're off to the side a few feet, well, it'll be off
a little bit, but it'll be close enough for most people,
because they're at the solstice, and they're at Stonehenge.
And that's what matters, because the Sun is coming up
and people are charmed by the convergence of all
- of these details. - Precisely observing
the sunrise at Stonehenge is complicated by the slanted
path the Sun takes through the sky.
When the Sun first breaks the horizon, it is just to
the left of the heel stone. Rising on a slanted path,
it travels up and to the right, eventually appearing over
the heel stone like a golf ball on a tee.
The summer sunrise alignment has troubled
observers who point out that today's heel stone is
tilted and once stood taller. In addition, when we punch in
a summer sunrise from 5,000 years ago,
our computer simulation shows the sun rising even
farther to the left. Does this seriously challenge
the precision of Stonehenge?
What most people don't realize is that there was
a companion stone, almost certainly, to the heel stone.
It is another one of the monument's
missing stones. The chalk hole in which it
stood was discovered in 1979, when a ditch had to be dug
for a local telephone line. Archaeologists excavated
ahead of the construction crew, and a long-hidden secret
of Stonehenge was revealed. Its existence may solve
the puzzling discrepancy surrounding Stonehenge's
- accuracy. - We don't know for certain
the two stones stood together, but it seems highly likely,
given the symmetry of things. These stones would've
stood symmetrically. Midsummer sunrise would have
risen exactly between them.
Accuracy in observing positions of the Sun
and Moon is the domain of space, but the Stonehengers
might have also sought precision in probing
the mysteries of time. The cycle of the Sun was
one tool, and the Moon, even better.
In terms of tracking time, the Moon may have been more
important to early peoples than the Sun, because what
happens with the Moon? The Moon goes through this
remarkable change in phases, from new, to where it's
completely invisible, to full, and back again.
The Moon's cycle of phases takes 29 1/2 days,
a time span that shows up at Stonehenge in the 30
Y holes and 29 Z holes. The holes were discovered
in 1923 and surround the main stone ring.
By counting 29 days in one month and 30 in another,
the early astronomers kept pace with the 29 1/2 day lunar cycle.
But counting the various rings and rows of stones
and holes at Stonehenge drives us even deeper into
its mystery. Why are there 19 stones in
one arrangement? Why are there 56 holes
in another? Could these numbers hide
an ancient code with the power to predict future
events in the universe?
The sky and Stonehenge appear to be silent partners.
No user manual exists, because the Stonehengers
had no writing. Still, they may have left us
a secret astronomical message encoded in numbers.
Consider the number four groups of stones and holes.
19, 29, 30, and 56.
What could these numbers mean?
These are numbers that only describe the periodicities
that can be associated with one unique astronomical object,
and that is the Moon.
While the 29 and 30 Y and Z holes represent
the lunar month, 19 small blue stones inside the big Sarsen
Circle represent the Moon's long-known Metonic Cycle.
Let's say we have a full Moon on July 4th of this year.
Well, next year, the Moon won't be full on July 4th.
It'll be some other phase. To have a full Moon on
July 4th again, you need to wait 19 years, and that's
the Metonic Cycle.
But the mystery of a Moon-based code goes even
deeper at Stonehenge. There's another hidden number
in a large outer circle formed by the baffling
Aubrey holes.
The Aubrey holes are named for John Aubrey,
who in the 1600s was one of the first people to notice these funny
indentations outside the stone circle at Stonehenge.
They are a set of 56 pits. They're evenly spaced in
a perfect circle just inside the ditch and bank.
The fact that the holes number 56 hints
at what may be Stonehenge's most controversial theory.
They've been thought, by some, to be part of an astronomical computer,
that the 56 holes could be used to mark the 18.6-year
cycle and 56-year cycles that underlie eclipse predictions.
What could the number 56 at Stonehenge
have to do with predicting eclipses?
If 56 is a lunar number, it must relate to the full Moon,
because without it, there can never be a lunar eclipse.
Suppose the Earth is here and the Sun is over there.
You can have a full Moon only when the Moon is on
the opposite side of the Earth relative to the Sun,
so it would be over here. Now, if the Moon, Earth,
and Sun are exactly in a straight line, the Earth
will cast a shadow on the Moon, and that's called
- a lunar eclipse. - The Stonehenge
eclipse computer, with its 56 Aubrey holes, may have
worked like this. After one lunar eclipse,
the challenge was to figure when it would happen again.
After 19 years in the Metonic Cycle, the Moon was full
on the same date but at a slightly different position
in the sky. When would it be not only full
but in exactly the same spot lined up with the Earth
and Sun for an eclipse?
The number that works is not 19, not 56,
but 18.61 years, the same time it takes
the Moon's back-and-forth trip on the horizon to expand
and contract. It's a way to pinpoint
the Moon's position and so predict the mystical arrival
- of a lunar eclipse. - During a total lunar eclipse,
the Moon can turn a deep orange color or even blood red,
so that must've been a pretty compelling, even frightening,
event for ancient peoples who worshiped it.
But the Stonehengers, without writing,
could not deal with fractions. Counting to 18.61 was
impossible, and that is where the 56 Aubrey holes come in.
The number 56 is also the sum of the number 19
and 18 and 19.
So by using the 56 Aubrey holes to count 19 years,
then 18, then 19 again,
the count per year averaged less than half a percent
from 18.61, the very number needed to track the Moon's
exact positions on the horizon and predict danger periods when eclipses might occur.
Without physical or written evidence, the eclipse connection
at Stonehenge is not widely accepted.
Skeptics believe numerical clues, like the number of
Aubrey holes, mean nothing.
The fact there's 56 of them--
well, there has to be some number of them.
I mean, it's 56 because it happens to be 56.
Or perhaps we have vastly underestimated
Stonehenge's astronomers. Was this monument really
a sacred observatory?
Until we find written records from that era,
if we ever do, or we build a time machine to go back,
really, we're stuck with plausibility.
But plausibility leaves open an astounding
conclusion, that the ancient shamans were astronomers and
Stonehenge their observatory. 5,000 years ago,
their observations achieved a level not seen
elsewhere in the world for almost 2,000 years.
Perhaps they were the first to map the path of the Sun across the year's seasons,
the first to calculate the lengthy cycles of the Moon,
and even the first to predict the timing of eclipses.
If so, the people of Stonehenge
were our earliest space scientists, embarking on
mankind's historic exploration of the universe.
Sync and corrections by n17t01 www.addic7ed.com