Greetings from Palmia Observatory
Well this week has had clear nights so we can show some DSLR shots of Mercury and Mars and Uranus, then comment on some space news and some more brief comments on AAS 237.
Capturing Mercury calls for a delicate balance between the sun having just gone down and the skies dark enough and still not having Mercury fall below the horizon. This DSLR, 75mm, ISO1600, 1/15 second image was taken at about 6:00 PM when Mercury was just about 3 degrees above the horizon. It took a while to scout around and find a good viewing site within just a 10 minute drive.
|Mercury, just after sunset, DSLR, 75mm, 1/15 second (Source: Palmia Observatory)|
The second photo session was a another practice shot of Mars and Uranus together in anticipation for the upcoming conjunction of Mars, Uranus and the Moon on January 20. This is an easy shot to make because Mars is very high in the sky. Hope the weather is clear for the conjunction!
|Mars, bottom right, and Uranus, top left, DSLR, 500mm, 1 second (Source: Palmia Observatory)|
It also happened just as I was about to use my calculator to do some field of view calculations for these images, that my calculator informed me that even this app is susceptible to data tracking and reporting. Wow, so now my calculator is going to tell on me! Ever since watching the documentary "The Social Dilemma", I have been on alert to watch for these kinds of events. Hmm, maybe it is because I have been doing too many field of view arc tangents?
|Say What? Even your calculator app tracks and reports (Source: Palmia Observatory)|
|Chang 5 mission returns lunar samples to Earth (Source: Leah Crane, New Scientist 12 Dec 2020)|
In that same issue, we see that Japan's Hayabusa 2 robotic mission has returned two samples of rocks and dust from asteroid Ryugu. The spacecraft ejected the samples from Earth orbit and they landed in South Australia where they were recovered. Meanwhile the Hyabusa 2 spacecraft still has plenty of fuel on board and ignited its engines for the trip back to the asteroid belt for another target opportunity. Pretty neat success for both robotic missions!
In other apace news, Virgin Orbit achieved a successful launch of their "Launcher One" on its second attempt. Here you can see the rocket attached on the underside of a Boeing 747. The aircraft carries the rocket to a high altitude where it is much easier for the rocket to get into orbit.
|Virgin Orbit Boeing 747 "Cosmic Girl", with "Launcher One", below wing (Source: M. Hartman/AP)|
"Cosmic Girl" took of from the Mojave airfield and flew out over the Pacific Ocean where the Launcher One rocket engine was ignited. Congratulations to the whole Virgin Orbit crew!
|Launcher One rocket ignition after separating from Cosmic Girl (Source: Jeff Foust, Spacenews.com|
His research has concentrated on how the comparison between measurements of the optical signal from an eclipsing binary pair of white dwarfs and the gravitational wave signal from that same pair. When LISA becomes operational in the 2030+ timeframe, gravitational waves from binary white dwarf pairs will be detectable. Then for those binary white dwarf pairs that are eclipsing binaries and observable from Earth, there is a chance to compare the speed of gravitational wave propagation and the speed of the photons coming from the pair.
|Phase difference between white dwarf optical and gravity waves (Source: G. LaMotte, 237 AAS)|
In this next slide screenshot you can see ideal signals from both optical and gravitational signals. The phase difference between the two signals can be used to constrain the mass of the graviton, which is also theorized to be massless, just like the photon. Hmm, we will have to just wait and see. What are you going to be doing in 2033+. Anyway thanks for everything, Gary, and see you online at the next April APS meeting in 2021!
|Using LISA in 2030+ time frame to measure phase difference (Source: G. LaMotte, 237 AAS)|
One other 237th AAS meetings showed two slides that explained how one common phenomena of gravitation accretion of material on a black hole can explain all of the strange and varied observations that have been made over a wide range of Active Galactic Nuclei (AGN). The toy model of an AGN is shown below. We see that material that is gravitationally attracted to the black hole is arranged in a pattern dictated by the physical properties of angular momentum conservation and the interplay between gravitational attraction and the hot flux of material pushing away from the black hole.
|Schematic Diagram of Active Galactic Nucleus (Source: Christopher Packham, 237th AAS)|
Dr. Christopher Packham used this toy model as a means to make sense of how all of the varied observations of individual AGNs can be explained based on our observational line of sight to the AGN. So, depending on which of the various structures is along our line of sight, you can measure different amounts of radio and optical and x-ray emission. All, apparently caused by accretion of material onto the black hole. Thanks for clarifying that picture, Christopher!
|Making sense of same structure but different observations (Source: Christopher Packham, 237th AAS)|
So, all of the energy released in an AGN is generated by conversion of gravitational potential energy into thermal and other forms of energy. It turns out that even here on Earth, we have examples of energy production that turn gravitational potential energy into electrical power. Just recall the use of hydrodynamic dams. We have also seen instances of energy storage based on pumping water up high and then at a later time letting the water flow back down hill through generators. But in the last issue IEEE Spectrum we find another energy storage system just based on lifting a heavy weight up in the Earth's gravitational field and then letting it fall back down and turn a generator at the same time. You can check out the various cranes and mechanical structures for the system in the image below. Energy storage systems have always held my interest because of previous years working on various types of electrical energy storage based on batteries, flywheels, super capacitors and even superconducting solenoids. Hope the mechanical project works out! We need more energy storage technology to better integrate variable solar and wind power into our electrical system.
|Gravitational Energy Storage System (Source: IEEE Spectrum, Jan 2021)|
Finally, one last article that showed up in New Scientist, was of special interest to me. It combined my interest in martinis with an interest in materials and interactions of molecules. It seems that shaking a martini, rather than stirring a martini, does actually separate the taste molecules in a way that can be noticed. Who knew that Shaken, Not Stirred was more than just a quote from James Bond. I do know from my own personal taste testing, that yes, indeed, "shaken" is the way to go! I elected not to buy the book, but the whole topic does sound kind of interesting. So, here is a shaken toast to everyone, especially Palos Verdes Dr. Ken!
|Hey, there is a physics based difference (Source: Claire Ainsworth, New Scientist 12 Dec 2020)|
Until next time, here from our burrow, stay safe, as we recover more of our freedom,