Decoding the ancient astronomy of Stonehenge

Summary

Stonehenge, constructed over a millennium around 5,000 years ago, is a prehistoric marvel with its final form still a subject of debate. The massive trilithons, standing at 9 meters, and smaller bluestones, weighing 3-4 tons each, were sourced from afar, with theories ranging from human transport to glacial movement. The site's astronomical significance is evident, with alignments to the summer solstice sunrise and winter solstice sunset, suggesting a deep cultural importance. Despite the lack of written records, clues like radiocarbon-dated antlers provide insights into the builders' methods and the monument's role in Neolithic society.

Takeaways

• 🏺 Stonehenge was constructed and modified over a millennium, starting around 5,000 years ago, but its final form remains speculative due to missing stones.
• 📏 The tallest trilithons at Stonehenge reach 9 meters and only three remain standing, with one being propped up in the 1950s.
• 🗿 The smaller bluestones, weighing around 3-4 tons each, were sourced from over 200km away, with debates on how they were transported.
• 🔍 The construction methods of Stonehenge are prehistoric, lacking written records, but clues like antlers used as picks provide insights into the process.
• 🕰 Radiocarbon dating of organic materials like antlers helps archaeologists estimate the timeline of Stonehenge's construction.
• 🏋️‍♂️ The outer sarsen stones, each weighing about 25 tons, had to be moved up to 20 km and were shaped using stone tools into uniform blocks.
• 🔨 The lintels, the top ring stones, featured intricate joints similar to woodworking, with grooves and bumps that fit together like puzzle pieces.
• 🎯 Neolithic builders demonstrated an early form of engineering by leveling the monument despite the uneven ground.
• 🌐 Stonehenge is part of a larger earthwork circle with additional features like the Heel Stone and a rectangle of stones possibly linked to moon cycles.
• 🌞 The monument's design aligns with celestial events; the central axis points near the sunrise on the summer solstice, indicating early astronomical knowledge.
• 🌕 The winter solstice was likely of particular importance, with the sunset aligning with the summer solstice sunrise, suggesting a winter solstice pilgrimage and feast.

Q & A

How long did the construction and modification of Stonehenge span?

The construction and modification of Stonehenge spanned over the course of a thousand years, starting around 5,000 years ago.

What are the tall structures in Stonehenge called?

The tall structures in Stonehenge are called trilithons.

How many trilithons are still standing today, and what is the height of the tallest one?

There are only 3 trilithons still standing today, and the tallest one is 9 meters or 30 feet high.

What are the smaller stones in Stonehenge known as, and where did they originate from?

The smaller stones are known as bluestones, and their geological source is over 200km away.

What is the debate surrounding the transportation of the bluestones to Stonehenge?

There is an ongoing debate about whether the bluestones were carried to the site by people or by glaciers some time long ago.

What are the outer stones of Stonehenge called, and how much do they weigh?

The outer stones are called sarsen stones, and they weigh around 25 tons.

How were the sarsen stones shaped and moved into position?

The sarsen stones were shaped into fairly uniform blocks using stone tools and then pushed into pits before being pulled upright.

What are the stones in the top ring of Stonehenge called, and what is unique about their construction?

The stones in the top ring are called lintels, and they have joints like woodworking joints with grooves that fit into bumps on the upright stones and also fit together like puzzle pieces.

How did the Neolithic builders ensure the monument was level despite not being on level ground?

The Neolithic builders were able to carefully calculate the heights of all the stones so that the monument was level even though it’s not on level ground.

What is the significance of the Heel Stone in relation to the summer solstice?

If you stood in the center of Stonehenge and looked toward the Heel Stone, you'd see the sun rise there on June 21st, which is close to the alignment of the central axis of Stonehenge with the sunrise on the summer solstice.

What evidence suggests that the winter solstice was particularly important to the people at Stonehenge?

The winter solstice sunset is on the same axis as the summer solstice sunrise, and archaeologists found pig bones from a settlement near Stonehenge that suggest an annual winter solstice pilgrimage and feast.

Outlines

00:00

🗿 The Mystery and Construction of Stonehenge

Stonehenge, a prehistoric monument, was constructed and modified over a millennium, beginning around 5,000 years ago. The final version of the structure, as depicted in the kit, is based on the existing ruins, although some stones are missing, leaving doubts about its completion. The tallest structures, known as trilithons, stand at 9 meters, with only three remaining today. The smaller stones, called bluestones, originate from a location over 200km away, sparking debate over their transportation method. These stones, weighing around 3-4 tons each, were moved significant distances without the use of wheels. The outer stones, or sarsens, weigh approximately 25 tons and were shaped using stone tools. The lintels, the top ring stones, were carefully fitted with joints, and the builders ensured the monument's levelness despite uneven ground. The site also includes a larger earthwork circle with a Heel stone and four other stones possibly linked to lunar cycles. The true significance of Stonehenge remains unknown, but it is believed to have an astronomical aspect, with the central axis aligning with the sunrise on the summer solstice.

05:01

🌗 The Significance of Solstices at Stonehenge

The solstices, marking the longest and shortest days of the year, were crucial for the food security of the Neolithic people who built Stonehenge. The winter solstice, in particular, seems to have been significant, with the sunset aligning with the summer solstice sunrise on the opposite axis. This alignment is mirrored in other ancient monuments like the Newgrange tomb in Ireland. Archaeological findings, including pig bones from a nearby settlement, suggest an annual winter solstice pilgrimage and feast. It is theorized that visitors would have entered the monument along an avenue, with the midwinter sunset visible through the tallest trilithon. Historian John North proposed that the monument's silhouette against the setting sun would have symbolized the promise of spring, reinforcing the importance of the solstices in the Neolithic culture.

Keywords

💡Stonehenge

Stonehenge is a prehistoric monument located in Wiltshire, England, consisting of a ring of standing stones. It is a significant archaeological site and is believed to have been constructed and modified over a period of about a thousand years, starting around 5,000 years ago. The video script discusses the various stages of its construction and the materials used, making Stonehenge the central theme around which the video's narrative is built.

💡Trilithons

Trilithons are the large, tall stone structures at Stonehenge, consisting of two vertical stones supporting a horizontal lintel. The script mentions that the tallest trilithon is 9 meters high and that only three of them are still standing today, with one having been propped up in the 1950s. These structures are key to understanding the engineering and architectural feats of the prehistoric builders.

💡Bluestones

Bluestones are smaller stones at Stonehenge, sourced from over 200km away. The script describes an ongoing debate about whether these stones were transported by people or glaciers. The term 'bluestones' is significant as it relates to the logistical challenges faced by the Neolithic people and the mystery surrounding the construction of Stonehenge.

💡Radiocarbon dating

Radiocarbon dating is a method used by archaeologists to determine the age of organic materials. In the script, it is mentioned that antlers used as picks to dig holes were radiocarbon dated, allowing archaeologists to estimate the chronology of Stonehenge's construction. This technique is crucial for understanding the timeline of the site's development.

💡Sarsen stones

Sarsen stones are the large, local stones used in the outer circle of Stonehenge. The script explains that these stones, weighing around 25 tons, were shaped using stone tools and moved up to 20 km to the site. The term 'sarsen stones' is important as it highlights the local resources used in the construction and the immense effort required to transport and shape them.

💡Lintels

Lintels are the stones that form the top ring of Stonehenge, and they feature joints that fit together like puzzle pieces. The script describes how these stones have grooves and bumps that interlock, showcasing the precision and skill of the Neolithic builders. The term 'lintels' is significant as it illustrates the advanced construction techniques used at Stonehenge.

💡Astronomy

The video script suggests that Stonehenge's design involved an early form of astronomy, as evidenced by the alignment of the monument with the sunrise on the summer solstice. This connection to astronomy is important as it indicates that the builders had a sophisticated understanding of celestial movements and incorporated this knowledge into the monument's design.

💡Summer solstice

The summer solstice is the longest day of the year when the sun is at its highest point in the sky for the northern hemisphere. The script notes that Stonehenge is aligned with the sunrise on this day, suggesting that it may have been significant for the people who built it. The term 'summer solstice' is relevant as it ties the monument to the agricultural and seasonal cycles important to the Neolithic people.

💡Winter solstice

The winter solstice, the shortest day of the year, is also mentioned in the script as being particularly important for the people at Stonehenge. The alignment of the sunset on this day with the summer solstice sunrise indicates a dual significance for the monument. The term 'winter solstice' is significant as it suggests a possible annual pilgrimage and feast at the site.

💡Heel stone

The Heel stone is a large stone located on the avenue leading up to Stonehenge. The script mentions that if one stands at the center of the monument and looks toward the Heel stone, they would see the sun rise on the summer solstice. This stone is important as it is part of the astronomical alignment and may have served as a marker for significant solar events.

💡Neolithic

Neolithic refers to the time period in human history when people began to develop agriculture and build permanent settlements. The script describes the builders of Stonehenge as Neolithic people, indicating that the monument is a product of this era. The term 'Neolithic' is crucial for understanding the cultural and technological context in which Stonehenge was constructed.

Highlights

Stonehenge was constructed and modified over a thousand years, beginning around 5,000 years ago.

The final version of Stonehenge is based on the ruins present today, but with some stones missing.

Tallest trilithon stands at 9 meters, and only three remain standing today, one of which was propped up in the 1950s.

Bluestones, smaller stones, originate from a geological source over 200km away, with debate on how they were transported.

Smaller stones weigh around 3 to 4 tons each, akin to moving 40 dead hippos without wheels.

Neolithic people left no written records but used antlers as picks, which can be radiocarbon dated.

Outer stones, sarsen stones, weigh around 25 tons and were moved up to 20 km using unknown methods.

Sarsen stones were shaped into uniform blocks using stone tools despite being harder than steel.

Lintel stones in the top ring had joints like woodworking, fitting together like puzzle pieces.

Neolithic builders calculated stone heights to keep the monument level on uneven ground.

Stonehenge is part of a larger earthwork circle with ditches and mounds.

The Heel stone and four other stones may be linked to certain moon cycles.

The site's importance to Neolithic people is unknown, but it involved early astronomy.

The central axis of Stonehenge aligns with the sunrise on the summer solstice.

The winter solstice sunset aligns with the summer solstice sunrise, indicating its significance.

Pig bones suggest an annual winter solstice pilgrimage and feast near Stonehenge.

Historian John North suggests the monument's silhouette during midwinter sunset symbolized the promise of spring.

Transcripts

Stonehenge was built and modified several times over the course of a thousand years

starting around 5,000 years ago.

This kit shows what the final version probably looked like based on the ruins that are there today.

But some of these stones are simply missing so archaeologists can’t know for sure that

this plan was ever actually completed.

These tall structures are called trilithons, and the tallest one is 9 meters, or 30 feet.

There's only 3 of them still standing today, but it would have been just two, except they propped one

back up in the 1950s.

These smaller stones are called bluestones.

The geological source for these is over 200km away, and there’s an ongoing debate

about whether they were carried to the site by people, or by glaciers some time long ago.

Even these smaller stones weigh around 3 or 4 tons, so it would be like moving 40 dead

hippos from DC to Philly without a wheel.

This is a prehistoric project, which means that the neolithic people that built it

didn't leave any written records about why or how they were doing this.

But they did leave behind some clues, like the antlers they used as picks to dig holes.

Because antlers are organic material, they can be radiocarbon dated, which is how archaeologists

can estimate the chronology of all of this.

These outer stones weigh around 25 tons.

Their source was more local, but they still had to be moved some 20 km. and archaeologists

can only guess how they did that.

They’re called sarsen stones and they’re harder than steel but they were shaped into

these fairly uniform blocks using stone tools.

And then they were pushed into pits before being pulled upright.

The stones in the top ring are called lintels and you can’t tell from this model but they

actually had joints - like woodworking joints.

There were grooves in the lintels that fit into bumps on the top of the upright stones and then on the side

of the lintels, they also fit together like puzzle pieces.

And not only that, but the neolithic builders who made this were able to carefully calculate

the heights of all the stones so that the monument was level even though it’s not on level ground.

Grass!

Ta- da!

Except we’re not actually done.

The stone circle was just part of the Stonehenge site.

It sits in a much larger circle that was drawn in the earth with ditches and mounds.

There was an avenue leading up to the entrance of that circle, a big stone on that avenue

called the Heel stone, and four other stones that form a rectangle and may be linked to

certain moon cycles.

This site must have been incredibly important to the neolithic people that built it, but despite

hundreds of years of analysis and speculation, we’ll never know for sure

what it really meant to them.

But we do know that it’s design involved an early form of astronomy.

In the 18th century, a historian noticed that the central axis of stonehenge points toward

the location on the horizon where the sun rises on the summer solstice.

So if you stood in the center of the monument and looked toward the Heel stone, you'd see

the sun rise there on June 21st — it’s not a perfect alignment, but it's close.

Summer solstice is when the sun’s path is furthest north, rising in the northeast and

setting in the northwest.

That makes it high in the sky in the northern hemisphere and low in the southern hemisphere.

This is all because the earth is tilted relative to it’s orbit around the sun, and the solstices

are where the sun’s path appears to pause and change direction.

But the people that built stonehenge didn’t know the earth moves around the sun or spins

on a tilted axes.

They probably didn’t even suspect it was round.

They just saw the sun bring longer days in the summer and shorter days in the winter

and those turning points would have meant a lot for their food security.

And there’s reason to think that the winter solstice was particularly important for the people

at Stonehenge. The winter solstice sunset is on the same axis as the summer solstice sunrise - just

on the other end, toward the southwest.

And the midwinter alignment shows up in other

monuments, like the Newgrange tomb in Ireland which has a window that

allows the sunrise to illuminate the inner chamber on the sunrise of winter solstice.

Archeologists also found pig bones from a settlement near Stonehenge that they believe

were slaughtered in the wintertime, based on the pigs’ age.

Their findings suggest an annual winter solstice pilgrimage and feast.

The idea is that people would have approached

the monument by walking on the avenue, which would have put the midwinter sunset in their

sightline, right in the window of the tallest trilithon.

Historian John North argued that when viewed from this side, the monument’s silhouette

would have looked like a solid black form, with the setting sun bursting through

bringing the promise of another spring.