Download Astronomy of the Pyramids - Home

Astronomy of the Pyramids - 1 of 3
Astronomy of the Pyramids
Brief Summary
The pyramids of ancient Egypt are precisely aligned with the cardinal directions (North,
South, East, and West). How did they achieve this engineering feat, and why? Explore the
astronomical connection between the gods of ancient Egypt and the alignment of the
pyramids.
Equipment Required







Merkhet (y-shaped staff)
Two wall sections
Two rocks
Rope triangle
Show #48 on Space Screen
Microphone
Space Screen Pickle (show controller)
Main Teaching Points



The pyramids of ancient Egypt are accurately aligned with the cardinal directions.
This is because they are aligned with the path across the sky of the stars and the Sun
(seen by the ancient Egyptians as gods associated with the afterlife).
We can recreate the methods that the ancient Egyptians may have used to achieve
this alignment.
Set Up





Gather the props – the wall sections, rocks, rope, and merkhet.
Gather the media components – pickle (show controller) and microphone.
After ensuring that it will not disturb present visitors, press STOP SHOW on the Space
Screen OCC, select show #48, and program in your microphone.
Move the wall sections so that one is on each side of the Space Screen. Put the
merkhet, the rocks, and the rope off to the planetarium side of the Space Screen.
Turn on PRESENTATION LIGHTING and announce the show.
Operating Tips

The show has many internal cues. When you click forward using the pickle, DO NOT
be tempted to click again if you see a black screen. This is the media controller
switching between still and video inputs. Be patient! It will seem like a long time when
1



Astronomy of the Pyramids - 2 of 3
you are up there – learn to use the time to continue your script so that your audience
will be ready when the image or movie begins.
If you need to go back, press the back button and then WAIT to see what happens.
The results depend on where you are in the show. Again, be patient! Once you see
what comes up on the screen, then you can click the back button again if you need to
do so.
At the end, the show automatically forwards from the end slide to the credits slide. Do
not press the forward button or you will drop off the end of the presentation, and won’t
be able to go back again. Once you are on the credits slide, you can press the BACK
button if you want to review any slides (See above for how to go back in the show).
You need to wait until a movie is finished before advancing. Otherwise, you will cause
problems with the cue system.
Questions and Answers
Did the pyramids align with magnetic North or polar North?
Polar North. Since the pyramids are made to align with the paths of the stars and Sun,
whose apparent movement is due to the rotation of the Earth, the result is that they are
aligned with polar North.
Don’t the stars and Sun have different rising and setting points at different times of
year?
The Sun does rise at different points throughout the year, but stars do not. While the time of
day/night when they rise and set changes, the location along the horizon (when seen from a
set viewing location) does not change. This is why they would have used a star, rather than
the Sun, to mark the artificial horizon.
Does precession play a part in this alignment of the pyramids?
Precession would not affect this method of finding East-West at all. Precession affects where
in the sky the North (and South) pole points, rather than the actual axis of the Earth.
Therefore, if you find the rising and setting points of a star now, then do the same thing in
several thousand years, the two resulting East-West lines will be exactly parallel.
Tell me more about the theory that they used the right-angled triangle to find the
North-South line.
The Rhind Papyrus (1832 BCE) gives historians an insight into the role of geometry in
ancient Egypt. The 3-4-5 triangle is one component of that. Today, we associate this triangle
geometry with the Pythagorean theorem. Pythagorus, a Greek, came much later, and there
is no evidence to suggest that the Egyptians understood this theorem. However, they did
understand that a 3-4-5 triangle rendered a right angle at one corner. In addition to this
written evidence, ropes with units marked by knots have been found. Some state that it
would be too difficult to get the accuracy we observe using ropes, since it is difficult to mark
units using knots, and the rope that would be needed to create a sufficiently sizeable triangle
would be prone to stretching. However, this is one possible method that they may have
used. See http://www.touregypt.net/featurestories/pyramidorientation.htm for more ideas.
How did the ancient Egyptians view the planets?
2
Astronomy of the Pyramids - 3 of 3
The ancient Egyptians recognized that there were 5 objects (the 5 planets visible to the
unaided eye) that moved across the sky compared to the stars. They saw these as deities,
often in boats, crossing the sky.
The Quest for Immortality exhibition (2004) didn’t mention much about the Sun and
stars connection to Ra and Osiris – why not?
The Quest for Immortality exhibit dealt much more with the later era of ancient Egypt,
whereas this show deals with the earlier era of ancient Egypt, the era during which pyramids
were built. Beliefs changed over time, and, while Ra and Osiris remained important, their
celestial connection diminished.
I hear about Re and Ra, and Seth and Set – are they different gods?
This is simply a difference of pronunciation. Re and Ra are the same god. Seth and Set are
the same god.
Background materials (websites, videos, articles, links)








http://www.touregypt.net/featurestories/pyramidorientation.htm - excellent article on
pyramid alignment, such as how they m ay have found the right angle, etc.
http://www.egyptologyonline.com/astronomy.htm
http://www.touregypt.net/featurestories/numbers.htm
http://web.bryant.edu/~history/h453proj/spring_99/geometry/Egyptian.htm
http://www.jimloy.com/egypt/345.htm
http://home.cwru.edu/~sjr16/advanced/pre20th_ancients_egyptians.html
Volunteer Guide for Quest for Immortality exhibit
Mummies Hall, 3rd Floor, DMNS
3