In Part 1 I posted about the pictographs that can be found at the “Diamond Solstice” site in Joshua Tree National Park. In this post, I will examine the theory of this site as a solstice observation site a little more.
If you look around the internet you’ll find references to this site as a solstice observation site. Those references all seem to point back to a single paper written in 1984. I got the opportunity to read the paper and from it learned that the site was observed periodically throughout fall, winter and spring, and it was observed that light never even entered the shelter during that time. On the morning of the summer solstice, though, the sunrise was said to immediately cast a shadow into the shelter, bathing the row of tally marks, and creating an “intense, vertical, finger-like beam of light pointing to the sunburst motif, but not quite touching it”.
Well! That sure sounds interesting. So, for the past three (!!) years we’ve trundled through the desert at an ungodly hour ( summer solstice is as early as the sun ever rises, after all! ) and set up shop by the shelter, hoping to see this display of light.
Results … have been mixed. While there isn’t nothing here, unlike at, say, the “Brunette Lady” where the claimed equinox display just doesn’t happen at all, or the “Shooting Star” site where the site layout is so generic that you can pretty much make it out to be what you want it to be, or the “Red Lady” where you can see the display of light on equinox and solstice alike ( and every day in between ) — we unfortunately did not see the beam of light. Yes, there was some sort of pointer and yes, it sort of pointed to the sunburst element, but … it really didn’t match the description.
Let’s look!
Not the first time I’ve anxiously watched the ridge line as sunrise approaches. This time I know better than to speculate that the sun will rise neatly through a notch or something. Sunrises do not work like that – they just come on all of a sudden.
The sky brightens as sunrise approaches. There were some clouds in the sky, which had me worried that we’d have a dud sunrise.
Off in the distance the tops of the hills are bathed in sunlight. Any moment now!
The shelter is faintly lit by the ambient light from the approaching sunrise. No shadows yet.
Now the sun’s rays are hitting the top of the formation above the shelter. We’re getting close!
I glance back at the skyline from inside the shelter. The sky is completely brightened now. Any ray of light will have to come in through this gap, so this is the shape that the sunlight shining into the shelter will take on. Note the absence of any feature that can be described as a “finger-like beam”.
Here we go! The light rapidly races down the formation towards the shelter as the sun rises.
A few seconds later there is a bar of light visible above the shelter. We tend to think of the sun as a slow-motion thing since we do not see shadows move unless we look at them for a while, but I’ll tell you, at sunrise things happen in seconds. You have to be quick.
And finally, the sun shines into the shelter!
If you glance back, you’ll see that the sun does sort of rise through one of those skyline notches, but that doesn’t really affect where the light falls. The notch is too far away and the light diffuses too quickly.
We wait but it is already obvious that there is no vertical bar of light for us here. That is as close as the light gets to the sun burst motif. It soon starts to retreat away from it.
The sun also shines into the alcove with the 29 tally marks.
On another visit it was a bright clear morning, leading to a stronger light.
Here we go again. The bar of light above the shelter, the bottom just beginning to light up. This time we’re a couple of days days early for the solstice, just to check. I examined the site’s orientation and it looks like the sun needs to rise further to the north for any chance at a vertical bar of light. It can’t rise further north than it does on the solstice, but I thought we’d try a couple days early this year, just to see if it is any different. The paper I read mentioned that the display was completely absent a week after the solstice, so I figured there was no point showing up later – plus, if you think about it, the days leading up to and away from the solstice has the sun at the same point in the sky, just moving north or south. So you don’t need to check just before and just after the solstice, you can check only one.
The sun fully rises, and the light is brighter than during our partly cloudy visit the previous year. But the light is no closer to the sun burst motif!
In a couple of minutes the ray has moved further right.
We stick around hoping something else might happen, but no luck. The ray disappears, the sun rises further, and the shelter is back in the shade.
So … what do you think? In three years of going out to have a look just before, or on the solstice, did we just miss the display?
I think we didn’t miss anything. In fact, I think the sun never gets any closer to the sunburst element than this. To understand why, consider the layout of the site.
The site faces almost due north ( so you face almost due south if you look at it ). Thus the sun shines into the shelter mostly side-on from the east, as you can tell by the shadows in the pictures. And as seen in the pictures that I took on the solstice morning, the light still needs to move quite a bit further to the left in order to reach the sunburst element. So, how can it move further left? Only by having the sun rise further to the north. But when does the sun rise as far to the north as it ever does? On the June solstice morning.
That explanation may be a bit tough to visualize, so take a look at this hand-drawn diagram I made. ( Note – not to scale. ) You should click on it to see the larger version where you can read the annotations. The black is the outline of the rock outcropping the site is found at, viewed from above. The site faces due north and is found inside the green dashed rectangle. The colored lines show the angle of light at sunrise on different days. They are also approximated on the picture in the lower right.
A diagram I made for you. Click it to get a larger version so you can read the text.
Finally, here is an illustration of the alleged solstice display, as found in the one paper, published in 1984, I have found on it. Compare this with the picture I took on the solstice.
Notice the beam of sunlight across the shelter floor, present both in the drawing and the pictures I took and showed to you. As we all know, sunlight travels in a straight line. Now notice how the “beam” splits off in the illustration, going its own way, against the grain of all the other shadows and light in the picture. How would sunlight bend by itself like that? It needs a gap of that shape to shine through, and there’s no such straight line present in the drip line of the overhang.
So … from my best efforts and research into this site over three years, it appears as if the report was a bit embellished.
An illustration from the research paper that seems to be backing all the references to this site as a solstice site. The display of light it illustrates was not present at the site during three separate visits on a day or two before the solstice.
I even went so far as to check the exact times of the solstice. As you probably know the Gregorian calendar isn’t entirely accurate ( hence leap years ) so the actual precise time of the solstice drifts throughout the years ( as you also know, it may be on the 20th or the 21st of June depending on the year. ) In 1984 the solstice was around 10:00 UT, and it so happened that the same was true in 2017. So this year we went one last time, right on the solstice, and found what you saw above.
Well, that’s the story of the Diamond Solstice site! The research paper states that the sun did not shine into the shelter at all during the equinoxes or during winter, and I would believe that based on the topography of the site, so I see no need to visit it at sunrise on other times of the year. I do think that the alcove with the 29 tally marks might be more interesting – those might mark the progression of sunrise across a season, perhaps – but I’ll leave that exercise to the reader!
So, in conclusion we have nothing to show for this but three visits to a wonderful site early on the morning of the longest day of summer.
If anybody has pictures of this site on the solstice morning that they’d like to share, let me know in the comments, with a link if possible so other readers can also take a look!
I have seen a photo relating to that finger of light. I’m sure I made a copy of it, but so far, can’t find it.
If I do, I’ll send it to you.
Thank you for the update! I’d be really excited to see it if you find it! If I have hope rekindled, I’ll probably post up there again during a solstice … but I have had bad luck for three years, trying on, just before, and just after the solstice, so I started having doubts.