The Grumpy Old Astronomer

"A Stonehenge Question"

Copyright © , Larry McNish All Rights Reserved


Stonehenge (not a tomb)
from: http://news.bbc.co.uk/1/hi/england/wiltshire/5098706.stm

The study of the design and very long history of Stonehenge is one of my "side-favorites" because of the way ancient people determined some pretty significant astronomical alignments (and limits) without telescopes, trigonometry, or even the wheel.
Like the ancient pyramid builders, I give those prehistorical builders a lot of credit for overcoming obstacles - and not just once, but hundreds of times, and all over the world.

I've written a couple of articles on this:

See my "Tomb Building 101" page: http://calgary.rasc.ca/tomb101.htm

And my "Stonehenge at Calgary?" page: http://calgary.rasc.ca/calgary-stonehenge.htm


Anyway, a while ago, during one of our many public star nights, a guy came up to me, in the dark, and started a conversation:

Him: They said you know about Stonehenge. Right?

Me: Yes I do.

Him: Then you must believe aliens built it too. Right?

Me: Pardon?

Him: Well everyone knows there was absolutely no way those builders could have ever lifted those huge stones on top of the others. So it must have been built by aliens. Right?
(He was obviously referring to the 30 Lintel stones that lay on top of the circle of 30 vertical Sarsen stones and the 5 Trilithon Lintels that lay on top of the "horseshoe" of 10 vertical Trilithon stones.).

(OK - now, I'm an Engineer. I know mechanics, and I also know physics, and I know the evidential history of Stonehenge. It took me no time at all to come up with a reply...)

Me: Well, IF it was my problem, I'd raise the standing stones, then fill the entire thing in with a ramp on one side - using all the dirt from the holes I dug and all the logs and other debris left over from dragging the stones half-way across England. Then I'd drag the stones on top of the hill, place them on top of the standing ones, then clean the whole mess away when done. Give me 50 guys and a couple of weeks and I'd have it all done.

Him: *mouth opened but nothing came out. *turned and walked away.

It was the first time I'd ever thought of the explanation because I had not previously spent time worrying about it. And it was obviously the first time he'd been confronted with a decent alternative.

Later I thought of why it came to me so quickly.

In today's world, people can't conceive of a large construction project without using bulldozers, back-hoes, dumptrucks, construction cranes etc. - all supervised by a Certified Project Manager and the Health And Safety Officer.

Got to lift a 100 ton block of stone? - Better call the specialized crane operators.

Need it done in a week / month / season? - Get more specialized equipment and trained, experienced operators.

Time is money!

Back then, there were no such things.

There were people that could look at a problem and come up with a solution given the resources and materials at hand.

Don't have any Water Systems Engineers? - Build the Roman Aqueducts anyway.

Need to build a road across a river? - Come up with the stone arch and lay a road on top of a bunch of them.

The Pharaoh wants to build a pyramid bigger than any of the hundred or so that have already been built? - Use a few generations of experienced craftsmen and someone to solve a few problems - or you are put to death.

And one possible significant reason for such progress:

Got a few hundred or a thousand warriors that just won some huge battles and now have nothing to do? - You'd better FIND them something to do, or they'll sit around and just might come up with the idea that their king (you) should be overthrown this winter.

So, you and your court astronomer (with his knowledge of the starry sky) come up with a plan to KEEP EVERYONE BUSY when they're not killing and plundering. And you give the project to him and a few bright guys. Then you give your very strong and determined and merciless soldiers a few years to do it, unlimited labour, food, water, and a place for their families to live.

Oh, and every few decades, another rich and powerful king gets saddled with the same "idle warrior problem" - so he tells his army that he wants one of the "old" wooden or stone henges torn down and a bigger, better henge built - or else.

And after one or two thousand years - you get Stonehenge.





P.S. "Another Stonehenge Question"


Question: How could they have determined the precise direction of the Equinoxes, the Solstices, and things like North, South, East, and West without like, Google Earth, GPS receivers, a compass or something, eh?

Answer: It's really not difficult at all - just find a large flat field.


  1. Start by putting a stake in the ground (the brown circle in the centre of the drawing above)
  2. Get a long piece of rope.
  3. Get a helper.
  4. Each morning, you watch from the stake as your helper stretches the rope till it points to the rising Sun on the Eastern horizon (example - the bright red line marked "A Sunrise" on the top right above).
  5. He places a stone at the "SunRise" end of the rope.
  6. Each evening, you watch from the stake as your helper stretches the rope till it points to the setting Sun on the Western horizon (example - the dark red line marked "A Sunset" on the top left above.)
  7. He places a stone at the "Sunset" end of that rope.
  8. You go to the "Sunrise" end of the line you made that morning.
  9. You look along the line towards the centre to see if the two lines make a straight line together. (Obviously, case "A" does not.)
  10. You go back to your hut and wait for the next day when you repeat steps 4 to 9.
  11. When the "Sunrise rope" and the "Sunset rope" together make a straight line (Case "C"), you've found due East and West.
    This occurs on only 2 days every year - the "Spring Equinox" and the "Fall Equinox".

Oh, and that red "A" line? If you did this every day of the year you would find that during mid Summer, the stones at the end of the red lines are clustered together - about 4 or 5 of them on top of each other. That means you have found the most northward position of the Sun - the "Summer Solstice" (since the Sun slows its apparent Northward progression, stops, and begins its apparent Southward progression around that day).

Oh and the dark blue "E" line? - It will end up telling you the exact direction of the "Winter Solstice".

So you know the exact directions of East and West and the Solstices. How do you determine North and South? You can't use Polaris the "North Star" because Polaris WASN'T the North Star ages ago due to something called Earth's Precession. And, you probably don't care either, because the other six directions are much more important to your society (especially the farmers).



But if you did want to find North and South, then just take two identical long ropes and stretch them out from the two ends of the East-West lines, then move towards each other in an arc till the ends meet (Point "X" above). Regardless of how long the ropes are (providing they're quite a bit longer than the other ropes), they will mark the North or South points for your henge. But as I said, this was probably not very important to them.

In other times, if you aligned the square base of your pyramid due East and due West as I've show how to do, the sides will naturally align due North and due South.


Even More About Stonehenge


If you're interested, here's a tiny version of the 31 megapixel "Plan of Stonehenge" scale drawing I created in 2015.





Stonehenge Station Stone Alignments (by the Author)
Base diagram from Wikipedia Commons.


Also see:

My suggestion for building a Stonehenge replica at Calgary

http://www.english-heritage.org.uk/visit/places/stonehenge/history/

http://www.stonehenge.co.uk/index.php

And search YouTube for "Operation Stonehenge" or "Stonehenge What Lies Beneath"
(There are several video uploads of the NOVA or BBC productions which get taken down and then show up somewhere else.)