Greetings from Palmia Observatory
Well this week we have some news about ongoing activities at SpaceX launch facility in Boca Chica, TX.
First up, we should mention that the recent web reference to the Starship SN5 test hop video by Marcus House was not correct and did not work. Thanks to Chemist, Arnold, for pointing this out to us! If you want to checkout the correct web reference for the test hop video, check out: https://www.youtube.com/watch?v=ZCGWX_ejolw
W now have photos of the Starship SN5 back on the ground after its successful landing. There is a lot of ongoing work there as they apparently get ready to modify the SN5 for another test hop.
|Hooray, Starship SN5 back on the ground after its test hop! (Source: NASASpaceflight.com)|
After that successful test top, work at Boca Chica continues at its normal fast pace. Here we see the next versions of Starship, SN5 and SN8, taking shape in the mid bay building. This building is used to stack together the various ring structures that make up the prototypes. It probably won't be too much longer till we see nosecones on those prototypes.
|Fabrication of Starship SN6 and SN8 in Boca Chica Mid Bay (Source: @Bocachicagal)|
But the mid bay building is not going to be big enough to house the complete Starship. For that job, a new high bay building is being constructed right next to the mid bay building. In this photo we see the ongoing construction of the high bay. You can also see the giant crane, Bluezilla, lifting new sections into place.
|High Bay construction with Bluezilla next to the Mid Bay (Source: @Bocachicagal)|
So we have all the amateur volunteers keeping tabs on what is going on at SpaceX facility in Boca Chica. In the photo below, we see some of the Starship nosecone prototypes all ready far along in the fabrication process as we get ready for the next stage of testing.
|Multiple nosecone prototypes are ready in Boca Chica (Source: RCV Aerial Photography)|
Well, as much as we wanted to be in Boca Chica to witness that test hop, we have other work to be completed here. First up was another look at the Many Worlds interpretation of quantum mechanics. In the popular press, the idea is presented as a case where there are multiple copies of the experimenters that perform quantum experiments. When an experimenter sends a particle, which is in the superposition state of being either spin up or spin down, into a Stern-Gerlach detector, we observe the destruction of the superposition and collapse of the wave function, called a measurement typically, and the output is just one or the other of the states. So, for my homework, I wanted to dig a little deeper into the Many Worlds view of quantum mechanics. Although the interpretation has fewer starting assumptions, the fact that it proposes millions of branches of the wave function, not collapse, and the resulting millions of copies of the observer, make it hard to believe.
There are many articles about the Many Worlds interpretation but I wanted to try to get a more mathematical description of what the theory was all about. Many Worlds claims to be simpler and rely of few assumptions than the standard Copenhagen interpretation, which just says the superposed wave function just collapses when a measurement is made, without the need for another experimenter in another world to make their appearance. I don't like it, but wanted to get a better understanding of how it is supposed to work. So, if you want to get more into the details you can check out these two books. I have had these books for a couple of years now and maybe this is the time to try them out. The branching tree diagram on this book sure gets things started in the Many Worlds interpretation.
|Many Worlds (Source: Many Worlds? Everett, Quantum Theory, and Reality)|
Anyway, to follow up on what the mathematics are behind the Many Worlds Theory of Quantum Mechanics, you can't get much better than this book by Dewitt and Graham. This book, "The Many Worlds of Quantum Mechanics" has good descriptions of the theory and also includes a copy of Hugh Everett's PhD thesis, where this whole concept got off to a good start.
|Many Worlds (Source: Dewitt & Graham|
Ok, so my eyes are starting to get tired after just a couple of dozen pages and luckily we received a note from Math Whiz, Dave, alerting us to an upcoming lecture by Professor Roger Blandford on Black Hole Astrophysics. The lecture is part of the Golden Webinars of Astrophysics provided by the Pontifica Universidad Catholica de Chile in Santiago, Chile. This is just what we were looking for so here is a brief summary of that presentation. Thanks for the heads up, Dave!
Blandford reviewed some astrophysics and the importance of rotation in generating some of the intense radiation from black holes, which is the main way they are observed. Now with LIGO, merging of black holes can be observed too.
|Black Hole Astrophysics - The role of rotation (Source: Roger Blandford @ PUC de Chile)|
The intense gravitational field around the black hole draws in a lot of surrounding gas and material. The material is accelerated to almost the speed of light and picks up a lot of kinetic energy and any material in orbit around the black hole is heated to very high temperatures. In this screenshot you can see equivalent amounts of energy from cases like, letting a 10 ton boulder fall a 100 meters on Earth, and how that same amount of energy would be released under other conditions for the black hole.
|Black Hole Astrophysics - Powered by Gravity (Source: Roger Blandford @ PUC de Chile)|
It turns out that kinetic energy of matter falling into a black hole is just of the methods that can result in a lot of energy emission. For rotating black holes, there is a lot of energy released from the resulting magnetic field and its interaction with matter around the black hole. This slide, showing what looks like to be a homopolar generator in the upper right hand side, was especially relevant to me in that many years ago I was look at large engineering systems like that for powering something like an electromagnetic rail gun. For the case of the black hole goes up something like the mass times the speed of light squared, so it is a very efficient method of turning mass into energy.
It is interesting to consider the units of Voltage (V), Electric Field (E), and Power (P) for a typical black hole magnetic field. You can see voltages of 1 zetta volt (ZV), which is one 1000, billion, billion volts and electric fields of 1 gigavolt (GV), which is 1 billion volts/meter and power equal to 10 to the 40th watts. Hmm, that is a lot of power compared to our sun whose total luminous output is something like 10 to the 26 power watts!
|Black Hole Rotation and the Magnetic Field (Source: Roger Blandford @ PUC de Chile)|
This huge power is radiated away from the black hole and appears to us through measurements as Active Galactic Nuclei (AGN), which are associated with maybe 1% of all black holes and the emission of energy then in large jets. The energy comes from accretion and magnetic effects from the spin. The formation of jets is associated with the intense magnetic fields. You can check out some of the details in the screenshot below. It was unclear to me whether the magnetic field can actually pass through the black hole or not. The diagram seems to indicate it can, but this is not clear to me. Maybe some reader can let us know what actually happens?
|Black Hole Astrophysics - Black Hole Jets (Source: Roger Blandford @ PUC de Chile)|
Blandford summarized his talk as shown in the screenshot below. The presentation was very informative and the whole video is supposed to be available online in a couple of weeks. If you want to look for that start at the university website at: http://astro.uc.cl/en/
|Black Hole Astrophysics - The role of rotation (Source: Roger Blandford @ PUC de Chile)|
If you want to follow up on the physics behind black holes this 2011 textbook does a pretty good job. It doesn't have some of the latest findings but does a good job of going over the astrophysics. You will need a bit of advanced math and some introduction to general relativity.
|Good textbook (Source: V. Frolov & A. Zenikov, "Intro to Black Hole Physics", 2011)|
Ok, that is enough astrophysics, and have just a brief geophysics report on the status of the recently installed Raspberry Shake Earthquake Monitor. Initially, I found I could see the seismometer output on my laptop, but it couldn't be accessed remotely from my iPhone app. Now, it mysteriously, just started working. I did try turning of our internet firewall, just for a minute, to see if that was why it was not working, but after turning the firewall back on, the app just started working. In this iPhone screenshot you can see the location and about 10 minutes of data for the selected seismometer. My unit, RA478, is just one of hundreds that are connected to the network. Unfortunately, I haven't been able to determine the units of scale for the display.
|ShakeNet iPhone app can remotely connect to Raspberry Shake (Source: Palmia Observatory) |
Another feature of the ShakeNet app is that you can display 24 hours of seismic data on the helicorder output. Some of those spikes around 1300-1400 UTC might be the time the observatory staff was waking up and traipsing and stumbling passed the seismometer on our way to morning coffee!
|ShakeNet iPhone app displays 24-hour Raspberry Shake Helicorder (Source: Palmia Observatory)|
Finally, since we should report on some astronomy related topics, we sat in on the online introduction to astroimaging webinar sponsored by the Orange County Astronomers (OCA). This webinar is part of the OCA Beginner's Class: How to Use your Telescope. Now, I had attended this class many years ago, when we could actually meet in person, but even now I learned a lot from watching this webinar. The thing that really stood out for me was the discussion about atmospheric seeing. We all have experienced this as we look at planets through the eyepiece of a telescope. The thermal instabilities in the atmosphere cause the light rays from the planet or other object to be distorted and to dance and wobble around. The neat thing introduced in the webinar was this slide showing how the atmospheric seeing can show up in a video recording of a star. Check out how the star appears in six seconds of video. That 6 seconds of video is made up of 375 frames. Look how the image just jumps around in most of them, but in some frames, in this case about a dozen of the frames, show little distortion from atmospheric distortion. This is pretty neat and alerts us how amateurs can compensate for atmospheric seeing. Professional astronomers can use computer controlled wavefront correctors and other adaptive optics techniques, but here we see how we can get pretty good, distortion free images, of bright planets and stars. Pretty neat, thanks for that OCA Kyle!
Until next time, here from our burrow, stay safe, as we recover more of our freedom,