Sunrise Mistake

I just watched the film Mackenna’s Gold for the first time. I would have liked it, if not for the sunrise. It is a treasure-hunting movie with gold lying around in a hidden canyon. The secret entrance to the canyon is revealed by the shadow of a big rock tower at the moment of sunrise.

The problem with this clue is that the azimuth of the sunrise differs depending on the day of the year. For example, at the latitude of Cairo, Tel Aviv or Los Angeles, the sunrise azimuth changes from 116 degrees to 62 degrees as the seasons change. This is more than a 40 degree span!

In any map where directions include a long shadow at sunrise, it should include the day of the year. To be more precise, the trajectory — of a given spot on Earth — around the Sun is not periodic. That means the Sun never rises at the exact same azimuth twice. If we are talking about the approximate azimuth, then the Sun rises in the same region two time periods per year. These periods are mirror reflections of each other, with the winter solstice as their focal point. That means MacKenna and his companions needed to wait for several months for the right moment.

I wonder whether the filmmakers knew about this mistake. I see two possibilities.

The first one is that no one noticed. This is very bad. It confirms that this country is illiterate. In fact, it is worse than that, since you don’t really need an education to know that sunrise and sunset happen at different points in the sky depending on the time of year. You just need to look out your window from time to time and pay attention.

The second possibility is that someone noticed, but the filmmakers decided to proceed with it anyway, on the assumption that the audience is too dumb to detect the error. Although there are Internet discussions of goofs in this movie, I was disappointed that I didn’t find any complaints about this mistake.

George Lucas borrowed many ideas for the Indiana Jones movies from Mackenna’s Gold. In particular, for Raiders of the Lost Ark he borrowed the sunrise mistake without the sunrise itself. In the movie the Sun is supposed to penetrate the crystal in the headpiece of the Staff of Ra and reveal the location of the Well of Souls. To do this, the Staff must be placed in a specific spot in the map room at a certain time of day.

The fact that the poetic idea of a sunrise was removed probably means that they knew that it was a mistake. It was replaced by a non-poetic certain time of day. But they kept the mistake. The Sun doesn’t repeat its trajectory every day. Like MacKenna, Indiana Jones would have needed to wait in the map room for several months for the Sun to be in the right spot. George Lucas opted for a fast-paced movie that disregards the laws of physics. The mystery of this movie for me is: Does anyone care?



  1. C. Burke:

    It’s been a while since I’ve seen Raiders of the Lost Ark, but I remember Indy checking a book before placing the staff in the correct hole, which was one of many. The series of holes could have been the required calendar.

  2. Tanya Khovanova:

    Yes, Indy was checking a book. When I was watching the movie, I interpreted it as if he was trying to find the only hole. If your interpretation is correct, the discussion might become more interesting. Still given the size of the window there are problems with this whole idea.
    Check, the discussion about the sun shining down the infinite corridor at MIT, know as MIThenge:

  3. Maxim Kazarian:

    You write: `the Sun rises in the same region two time periods per year. These periods are mirror reflections of each other, with the winter solstice as their focal point’.
    I have heard that the length of the light day as a function of the date is not exactly symmetric with respect to the winter solstice day. Besides, this function is not equal to the function describing the length of the night with the argument shifted by half a year. Don’t you know to what extend it is correct and what would be the reason?

  4. Raj:

    Your two interpretations are so ridiculous, it makes me laugh…. First of all, mistakes like these happen all the time…. This is HOLLYWOOD, it’s not bloody NASA (and you will be freakin’ surprised as to how many mistakes those idiots make too, given that they are so msart)…. The story is “dramatized” so as to suit the script as and when required…. If you make each and every bit “realistic”, then it wouldn’t be fun, it’d just be as drab and mundane as you and your life — pointing out mistakes in a classic movie like Mackenna’s Gold…. What’s your achievement in life, have you won a Nobel Prize, or invented something ??? For all one knows, you are just a sad pathetic jackass who is so full of himself, he doesn’t even have a social life…. Congrats dickhead, no 1 cares about your retarded observation (I commented because I feel idiots like you should be put in their place)

Leave a comment