Greetings from Palmia Observatory
Well my social media site reminds me of past events and this time was when we were at Kennedy Space Center for the first launch of the SpaceX Falcon Heavy with Starman aboard Elon's red Tesla.
Here you can see some of the photos of the launch from that time 3 years ago. If you want you can see a good video of the launch and the recovery of two of the boosters that successfully landed at: https://www.youtube.com/watch?v=wbSwFU6tY1c&feature=youtu.be
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| Watching the launch of Falcon Heavy on Feb 6, 2018 from KSC (Source: Palmia Observatory) |
In other SpaceX Starlinks news for those of you in Southern California, we have a possible viewing opportunity Saturday morning between 5:12 and 5:18 AM. So the weather forecast says partially cloudy, so if you dare get up early, have some coffee and go out and try to see the string of pearls. The predicted magnitude is 3.3 so you will need good eyes to see them. I'll will try with my DSLR and long exposure. A good starting location to point your camera is right at bright star Vega.
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| Heavens-Above forecast for Starlinks viewing in Orange County (Source: Palmia Observatory) |
We also found some other great photos of the test flight of Starship SN9. As we reported in the last blog, everything went well until the final landing attempt when one of the engines failed to ignite. So, even with the explosion on impact and Rapid Unplanned Disassembly (RUD) debris flying all over the the place, Starship SN10 and the old Star Hopper were not damaged.
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| Another viewing angle of the Starship SN9 RUD (Source: @GreatSpaceX) |
The Starship has 3 engines SpaceX might update the landing procedure to include all three, even though only two are required for landing. At the same time using all three engines is more difficult because the Raptors do not throttle down very much. Here you can see all three engines in this photo forwarded by @greatspaceX.
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| Great view of the three engines on Starship (Source: @GreatSpaceX) |
Ok, now back to some news for all of you physicist wannabes out there. For months now I have delayed trying to use a Python add-on library that can do symbolic calculations in general relativity. So, it is easy to add this new library, Einsteinpy, and to very quickly do some actual calculations. In the screenshot below you can see the form of the Schwarzschild metric for a black hole is used as the starting point. This metric defines very well the distortion of space time around the black hole. But if you want to do any dynamic simulation of particles flying past or falling into the black hole you will need to first of all calculate the Christoffel symbols. So the second part of the screenshot shows the four Christoffel symbols that are associated with the Schwarzschild metric.
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| Using Einsteinpy and Python to do general relativity calculations (Source: Palmia Observatory) |
So, we started with one matrix, which was the matrix, and now after calculating the Christoffel symbols we end up with four more matrices. The reason for this is that the calculation involves the derivatives of tensors which results result in tensors of one higher dimension. So you have to do like 48 differentiations, but luckily most will turn out to be zero by symmetry of the metric. Nonetheless, I am glad not to have to do all of this hand. Once you have calculated the Christoffel symbols these can be used to solve geodesic equations for motion of particles around the black hole or object described by the metric. You can see how the calculation goes in the following section from Sean Carroll's textbook, "Spacetime and Geometry." Equation 3.27 shows how the Christoffel symbols are calculated by summing various derivatives of the metric.
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| Calculating the Christoffel symbols (Source: Sean Carroll, "Spacetime and Geometry") |
Ok, ok, enough of GR for the moment and we can turn to the last Distinctive Voices lecture. We used to enjoy actually travelling to the Beckman Center to hear the National Academy of Sciences lecture live and to meet and greet all of our other associates and friends. Now it is all online and seen on Zoom and it is not quite as much fun to watch the event on a tiny computer screen. Anyway, Wednesday's evening lecture was presented by Nick Touran on "How Offshore Nuclear Power Stations can help achieve rapid and deep decarbonization."
Hmm, when I first heard this title I thought that that was a crazy idea. Ok, sure, we need to make a transition away from burning fossil fuels, but to build offshore nuclear plants sounded definitely crazy, but Nick made his case. Worldwide, we rely on energy for freedom and comfort.
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| Energy usage gives us freedom (Source: Distinctive Voices lecture by Nick Touran) |
There are many parts of our energy economy and if you just look at electrical energy use worldwide you see how uneven the distribution is. As a retired energy engineer, my position is not to deny everyone else access to energy, but to make more energy cleaner and less carbon producing.
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| Electricity use per capita around the globe (Source: Distinctive Voices lecture by Nick Touran) |
Yes, most of electrical production relies on fossil fuels. One way of transitioning away from burning fossil fuels is to rely more on renewable energy and even nuclear energy.
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| World energy use by source (Source: Distinctive Voices lecture by Nick Touran) |
As a side note, some of you might have read a separate book on the subject of energy use though out the world and how it has increased the wellbeing of everyone. So, Nick did not go into this, even though it is part of his argument, you can check out Stephen Pinker's book, "Enlightenment Now."
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| Good description of human progress and access to energy and free markets (Source: Stephen Pinker) |
Touran's main point of his argument is that nuclear power is a good way of decarbonizing our electrical infrastructure. If successful, there will still be other parts of our economy, such as steel and cement production and airplane travel, that will be harder to decarbonize. But, his point is that the cost of building nuclear power plants can be much reduced by building them more on a factory type assembly line and then moving them to the point of use.
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| Cost drivers and reductions for nuclear plants (Source: Distinctive Voices lecture by Nick Touran) |
A modern shipyard is a modern location that is ideal to do this. So, what Touran advocates is the mass production in factories, like shipyards, and then transporting the reactor power systems in ships to the point of use. This shortens the fabrication time and the costs of financing the production.
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| Shipyards and efficiencies of factory production (Source: Distinctive Voices lecture by Nick Touran) |
Surprisingly, this concept of mounting nuclear power plants on ships is not new. We all know of nuclear powered aircraft carriers. I did not realize though that the fabrication of floating nuclear power plants had ever been permitted, but here we see an example from the 1980's.
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| Offshore power systems almost made it (Source: Distinctive Voices lecture by Nick Touran) |
The remnants of a located in Florida that once was built to build licensed, floating nuclear power plants are still visible, but it turned out that at that time, in the 1980's, there was no demand. Now there is increasing demand for decarbonized sources of energy.
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| Remnants of Offshore Power fabrication unit (Source: Distinctive Voices lecture by Nick Touran) |
Now I have visited nuclear submarines and carriers and worked on some propulsion systems and there we see the benefits for stealth and long cruise durations, but what about mobile nuclear powerplants, made to deliver power to shore? Well, it turns out that several prototypes have been built and offer a lot of advantages. The ships can provide electrical power and desalinated water to those on shore. This is a convenient way of providing those services to communities along the seaboard. In fact, the Russian's Akademik Lomonosov is capable of doing just that.
Of course, notwithstanding the value of these floating power plants, many pundits who do not like the idea, call out these ships as "Mobile Chernobyls." So, we see even if the economic case can be made for floating nuclear power plants can be made, there will still be potential opposition.
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| Some offshore floating nuclear plants are here (Source: Distinctive Voices lecture by Nick Touran) |
Another example of floating nuclear power plants is China's ACPR50S, which if recall correctly could deliver 50 megawatts of power to the shore.
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| Some offshore floating nuclear plants are here (Source: Distinctive Voices lecture by Nick Touran) |
So, Touran summarized the pros and cons of relying on floating nuclear powerplants in rapid decarbonizing our electrical systems. Manufacturing the plants in factories like shipyards can go a long way in reducing the construction costs. It turns out that floating platforms are not at risk due to earthquakes or tsunamis. They do have to contend with possible rogue waves and ocean going ships running into them. They can be located offshore which lessons the potential for risk to human life if their containment systems fail, but the floating ships are also surrounded by a source of cooling water that greatly reduces the risk of core melting.
I didn't see the "con" of submarine power cables because this is a well establish technology for offshore wind turbine farms. But all in all, I think he presented a new way of looking at the pros and cons of nuclear power.
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| Final summary slide for OPS (Source: Distinctive Voices lecture by Nick Touran) |
Readers of this blog will remember that our post of October 17, 2019 commented on a startup, TerraPower, financed by Bill Gates, that also advocated the factory manufacturing of smaller nuclear reactors as a significant cost reduction plan. There is another startup that is proposing to do the same thing. So, even if making the plants mobile turns out to not gain acceptance, it might be that the lower cost of factory produced plants might gain acceptance for land based applications. Here is an example from another nuclear startup, NuScale.
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| Nuscale offers one version of small factory produced nuclear plants (Source: Nuscale) |
So in summary, from my own point of view this idea of making smaller nuclear plants in a reduced cost factory setting has a lot to say for it. The plants can be made with big improvements in safety designs. So, even if the mobile application doesn't find any interest the smaller units might.
Until next time, here from our burrow, stay safe, as we recover more of our freedom,
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