Greetings from Palmia Observatory
Well this week has mostly been happy and involved with more social activities as more and more restaurants and meeting places open up for real in person meetings. Yeah! In addition, we have commented about the recent annular solar eclipse and have been looking for some other full moon observing opportunities.
Not just any old full moon, but a full moon near the horizon where its size in comparison to things on the horizon make the photo interesting. For instance, Moved to Florida, Bill, sent in this great picture of the moon juxtaposed to the Cape Byron Lighthouse. This is always an interesting photo. Thanks for reminding us, Bill!
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| Cape Byron Lighthouse, Australia, with full moon (Source: Luke Taylor) |
Now, I like the idea of recreating that same type of image, but we don't have many lighthouses out here in Orange County. But we do have some tall buildings and other structures so we might be able to duplicate that type of image with full moon and some other structure on the horizon.
How to we select a camera position to duplicate this type of photo? You need to be in a position so that the moon on the horizon is in the same line of sight between you and the object on the horizon. The full moon will always have an apparent size in the sky very close to 30 arc minutes, or 0.5 degrees if you prefer, no matter your location on Earth. The building on the horizon will have an apparent size that depends on your distance away from the structure. So, for a given lighthouse or structure, say about 200-300 feet tall, we just need to calculate what distance is required so that the apparent size of the building is also in the 0.5 degree range.
The sketch below shows the calculation needed to estimate the distance. We assume a right angle trigonometry and just solve for the required distance. For a building of 200 feet tall, the distance from the camera to the building is seen to be about 22,900 feet or let's say around 4 miles.
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| Distance (4 miles) from 200 foot tower for same angular size of moon (Source: Palmia Observatory) |
Can we find an equivalent tall structure out here in the metropolitan area of Orange County? Well, maybe we can use on of the tall skyscraper buildings and use that and plot the course of the moon and create the same type of image. One of the tallest buildings in OC is the Spectrum Center with 21 floors and rising about 300 feet. Let's use that as an example to try to find a point that has the tower about 4 miles away and a viewing location that puts the tower on the horizon where the moon is just going below the horizon.
In this map section we have plotted a 4 mile radius circle centered on the location of the Spectrum Tower. A black line is oriented at 124 degrees azimuth, which is the predicted location for the moon on the horizon on June 24 and June 25. So, our task now is to find a line of site location where we have a good view of the tower.
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| Apple Map view showing 4-mile distance from tall building (Source: Palmia Observatory) |
Well, instead of being clouded out, we were treed out, during most of our searching along Jeffrey road. We had a good view of the Tower from the top of the 5 Fwy overpass, but after that it was just trees and more trees. One visible opening in the trees was along the electric transmission line right of way as seen in the image below. This iPhone image has about a 120 degree field of view (FOV). You can just barely see the Spectrum Tower behind the 2nd transmission tower.
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| Iphone image of tall building from about 1.5 miles away (Source: Palmia Observatory) |
The Spectrum Tower shows up much better in this expanded and cropped image. Using the original 120 degree FOV, we can count pixels and determine the width of the Tower is about 1.7 degrees. So, yes, we are too close to the tower to have the moon image show up as larger than the Tower. Besides that the azimuth reading is pretty close to due east, 90 degrees. So, this only visible observing location does not have the right azimuth angle to capture the moon on top of the Tower.
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| Cropped version of tall building from 1.5 miles away (Source: Palmia Observatory) |
So, I was pretty disappointed and decided not to go out to the full 4 mile distance because the streets would have heavier traffic and the trees were again probably going to block the view of the Tower. Any other OC residents have a good observing location in mind that meets our requirements? It might be easier to just use a high transmission tower as the target on the horizon in stead of a building?
I considered various high rise hotels at the 4 mile distance, but none were located on the 124 azimuth line. Besides, I'm not sure I want to rent a hotel room just to take a photo of the moon on the horizon. But it turns out there might be other rooftop locations that might be available and wouldn't cost anything. The Hive and Honey rooftop restaurant, in the Marriott Spectrum Hotel, is one location that we elected to check out. It is way too close to the Spectrum Tower to be of any use, but it might be useful to just go there and get a sense of what the viewing could be like. Besides, if it will be a good adventure to try a martini or two while looking on on the OC skyline.
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| Possible observing site with good watering hole (Source: Hive and Honey, Marriott Hotel) |
So, Resident Astronomer Peggy and I took off for our Taco Tuesday adventure at the Hive and Honey Rooftop Bar to check out the food, drinks and of course, the viewing.
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| Resident Astronomer Peggy ready to check out the rooftop (viewing) bar (Source: Palmia Observatory) |
In this northward looking view, I could get right next to the roof top edge and you can see a clear view of mountains and the big balloon at the Great Park. So, you might be able to consider this as a 16 story concrete pier, on which to mount your scope, but the tenants and guests might object to such operation.
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| North looking viewing with Great Park Balloon from the rooftop bar (Source: Palmia Observatory) |
In summary, the food and drinks at the Hive and Honey rooftop bar were very good, but quite pricey. The viewing was pretty good, but in most directions there were occupied tables next to the rooftop edge so it was a little tricky getting close enough for some good shots. When we got back to the observatory, we found that my friends at the Post Office delivered a package with some merchandise that was ordered from Sean Carroll, who tweeted that he too now offers some physics friendly "merch" for those who follow his podcasts. Well, I am not a big Tee shirt fan, and can't really offer a flat surface to display such a shirt, but here it is.
This idea that the evolution of the universe over time has entropy continuously increasing and the complexity of the universe rising to a maximum and than declining back to essentially zero again is, to me, one of the most fascinating predictions of modern physics. At the time of the big bang, the entropy and complexity are predicted to be low. As the universe evolves, the entropy increases in accordance with predictions of the 2nd law of thermodynamics and the complexity, in terms of cosmological structure also increases, first in terms of gravitationally bound stars and then galaxies. Life show up in some middle position as identified by the "You are here sign." Then eventually, after billions and billions of years and the matter of the universe has fallen into the increasing number of black holes, the complexity starts to decline but the entropy keeps increasing. Then after billions and billions more of years and the black holes have evaporated away, there is little complexity and yet much entropy.
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| Resident Astronomer with Complexity-Entropy Curve on T-shirt (Source: Palmia Observatory) |
But, the good news is that we can enjoy ourselves here and now where the entropy is ok and the possible complexity makes us possible.
Until next time,
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