Are there any astronomer mumsnetters? It's a long shot I know but would appreciate somebody helping me with an odd question.

[Dragonbrandybutter]

I know, i know this has nothing to do with parenting so this is probably not the place to ask this question but I am always amazed at what mumsnetters know...

I need someone to explain about the egyptian pyramids and their alignment to the stars Kochab and Mizar. If you wanted to draw the relationship between the stars and the pyramid how would you show this. Would the stars line up directly above the pyramids or somewhere else?

There are plenty of resources on the web relating to what is called 'The Orion Theory', including a number of diagrams which illustrate this alignment. Just Google for 'orion pyramids' for a selection.

The consensus among Egyptologists is that any apparent alignmnet is a coincidence. The first hit on the Google search above does quite a good job of explaining why.

Oooo sorry, I must read more carefully . The Kochab-Mizar alignment is something entirely different.

The pyramids are aligned with their square bases facing roughly North, South, East and West. If we wanted to find North, we could use the Pole Star. But at the time the pyramids were built, the Pole Star was not aligned with the North Pole, so the Egyptians must have had some other way of ascertaining North.

It has been suggested that they used the stars Kochab and Mizar to find North. There is nothing special about these two stars, they just happen to have been in the right place about 5,000 years ago. It is true that if you stood due south of a pyramid, then yes when the line joining these two stars was vertical, that line would have gone through the top of that pyramid.

I am not explaining this very well - have a look here instead

ah bless ya MrV

10/10 for effort.

i did actually find some pretty good stuff that explained all this while doing some late night googling.

well done mr vibrating.
from what i understand the scientist have been able to date the pyramids to the few years when the two stars would have been aligned vertically to show north.

ok, so if I was standing due south, is that the front of say the Giza pyramids?
so i would show the pyramids facing me? with the stars aligned directly above?

i found this picture to onnature.com but i want to know whether that is the front or the side of pyramids showing.

bloody hell this is confusing.

sorry.

head explodes

would it help if i explained why i want to know?
i am entering a mosaic into an exhibition. it is linked to international year of astronomy. i want to illustrate early astronomy and think the pyramids and stars and ideal mosaic material.
i'm just struggling with the composition as i want it to be accurate.

oooooh

I like the sound of that

erm hang on

Had a moment of inspiration.

Have you googled the Mathmatics of Early Astronomy or sumat along those lines?

That picture on nature.com is (surprisingly) not accurate in any way.

Also, bear in mind that most people who are interested in this kind of thing (this is a branch of astronomy called paleoastronomy) do not attach any significance to this so-called Kochab-Mizar alignment.

Most people think that the Egyptians used the sun to find North, not the stars.

But it would make a good mosaic. There is no reason why you should not show the stars as in that picture on Nature (leave out the curved lines, they are wrong anyway), with the line going straight into the apex of any of the pyramids. The south face of the pyramid (not the corner) should be facing you, so all you see is a triangle. You could either do a close-up of just one of the pyramids, or if you put the alignment over the middle Giza pyramid you could view it at a distance with the other two pyramids each side. You can get the dimensions with a bit of googling, or use Google Earth to get a plan view so you can get the bases right and work out the perspective.

hooray for mrvibrating.
i'm off to google earth!

so what's with the lines on the nature.com picture? what would be more accurate?
shame, they would have added to the mosaic.

thanks

I may have been a bit hasty with my condemnation of the Nature picture. The curved lines are OK as they are drawn, the problem is that that picture has a vertical field of view of nearly 90 degress - the point where the lines converge is directly above the observer's head!

I would be inclined to use a more realistic field of view of 45 degrees by cutting the picture in half vertically.

This will also give you more room to fit in the pyramids underneath Kachab. If you would like something a bit bigger to work with, here is an image I generated that confirms the accuracy of the star positions in the Nature image. That image actually uses a field of view of 50 degrees to fit in Benetnasch at the tail of the big dipper. Note that the Egyptians used different constellations, so I would not show the constellation lines on your mosaic.

Unfortunately the site I used cannot show lines of azimuth and declination (the curved lines). Starry Night is the gold standard of astronomy software, but I don't have it to hand.

So Aliath Mizar is Mizar?
What does the little cross represent?

so i would draw the pyramid directly below Kochab? (but mizar isn't directly above, or am i looking at the wrong white dot?)

am i annoying you yet?

FWIW i'm annoying me

got it! alioth and mizar are different stars, just that the text was close. and yes they are aligned.

so i could draw a triangle for the pyramid as no other sides would be visible.
line it up directly below mizar and kochab.
i could also place the other stars but not include constellation lines.

have i got it now?

you hairy truckers really are founts of information!

Yes, you have it. The little cross is the celestial North Pole, the imaginary point around which all the stars appear to rotate.

I have thought a bit more about this today, and an alternative scene would be to sight along a side of one of the pyramids, with the stars above that side. This would be how the alignment could have been used to align the pyramids during construction.

I can't explain this very well so I'll do a couple of sketches.

ok, sounds good.
how do you know this stuff?

I have done a couple of sketches - actually they are not really sketches because I managed to find a 3d model of the pyramids for Google Earth which saved a fair bit of pencil work . I also used some decent planetarium software to generate an accurate starscape.

Email mr dot anchovy at mranchovy.com for the images.

How do I know this stuff? Well I don't know very much about the Pyramids actually (as evidenced by my mistake about using the sun for alignment - it seems the evidence is that the Egyptians used the stars after all). I do however have an interest in European neolithic astronomy, and so I was happy to research this for you; I have learnt a fair bit on the way . I also have an interest in art, particularly the development of formal perspective in the European Renaissance.

So this is right up my street!

will email shortly. thanks.

Absolutely brilliant.
Will need to print off tomorrow and read it all when not so tired but i think the pictures look great.

Yes, i knew about the pyramids being smooth and white(?). will look very good in mosaic.

i'll keep you posted on how it's going.

thanks