Well this week we didn't get any astronomical observing done, but can talk about Sean Carroll's exciting newly released book and also explore a little bit about nuclear isomers as an exciting energy storage technology. But first,
let's mention two upcoming calendar events that might be of interest to many of you readers. First is the upcoming tour of Sunspot and Apache Point Observatory, near Las Cruces, NM, which is part of the scheduled American Association of Visual Star Observers (AAVSO) annual meeting their on October 18-21, 2019. You can check out the details at their website at: https://www.aavso.org/las-cruces-annual-meeting?_ga=2.248938631.1200773728.1568570346-1656206784.1524594626
See you all there! Secondly, we were disappointed to learn that we are overscheduled and couldn't attend the upcoming OCA/LAC tour of the James Webb Space Telescope (JWST). However, we discovered that the Ventura County Astronomical Society is also sponsoring many different dates for tours of the JWST, while it is still under test at Northrop Grumman in Redondo Beach. If you are interested in a tour, check out this other local astronomy club website or send Dr. Phil your interest at: https://www.citizensjournal.us/ventura-county-astronomical-society-opportunity-fall-james-webb-space-telescope-tours-announcement/
See you all there, also! Ok, now back to the exciting new book by Sean Carroll, "Something Deeply Hidden" which was just released.
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| We have all been eagerly waiting for the release of this book (Source: Sean Carroll, "Something Deeply Hidden") |
Well, I have been looking forward to this book sometime now, especially since I follow Sean on his Mindscape podcast and have been expecting this book for quite a while. Also as a physicist wannabe, who has been growing disappointed with the Copenhagen interpretation of quantum physics and the measurement problem, now looking forward to perhaps a better approach to the foundations of quantum mechanics call the Multi-worlds interpretation, or more correctly just a different, but maybe more consistent, yet still testable, theory of quantum mechanics. So, no better way than to start the book over breakfast while enjoying just being outside in the warm weather.
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| A little light breakfast outside with a copy of "Something Deeply Hidden: (Source: Palmia Observatory) |
Then after breakfast, or perhaps at least simultaneous with breakfast, we getting studying the book with the help of Mr. T and his famous bloody Mary mix.
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| "Something Deeply Hidden" begins with an introduction to the double slit experiment (Source: Palmia Observatory) |
Well it wasn't long before the bloody Mary was gone, not because of Sean's discussion, but because it was getting hot in the early morning, but nonetheless. I had a breakthrough understanding of a concept in quantum mechanics. Sure, I sort of had a hint of this before, but I never quite got the concept that when physicists talk about "up" and "down" spin of particles that all of this was quite arbitrary and that it was perfectly acceptable to use as basis states, "left" and "right" or some other coordinate basis. The point is that if some observer starts with up and down it is easy to use the mathematics of quantum mechanics to switch over to results to be observed in say left or right coordinates. Thanks for helping me out with that Sean!
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| Working through the arbitrary coordinate references of Up, Right, Left and Right in QM (Source: Palmia Observatory) |
On page 92, we find another of those "aha" moments. Now we all have probably seen many times that if two equal particles collide head on, we know that from the conservation of momentum principle that if one particle heads off in one arbitrary and random direction, that the other particle will automatically head off in just the right kind of opposite direction such that the momentum of the system stays exactly the same. But here Sean introduces the concept of entanglement and the idea that if a pair of entanglement particles is measured separately, then after the first measurement we will know immediately what will be measured for the second particle. This is the first time that I had heard that conservation of momentum might be ties up with entanglement. Pretty neat, again thanks for that Sean!
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| "Something Deeply Hidden" diagram showing connection between momentum and entanglement (Source: Palmia Observatory) |
Finally on page 115, out of 325 pages, we see the key part of the Multi-Worlds theory of quantum physics. Keep in mind that the key point is not that many worlds are being created out of nothing, but the more appropriate way of looking this Multi-Worlds theory is just that the wave function of the universe splits and diverges just in accordance to what the Schrodinger equation says should happen. The following diagram from page 115 points out this idea.
We start off with a particle in the spin down state and after interacting with the measuring device, the device indicates that the particle is indeed in the spin down state. All of this is spin regardless if the original state were spin up or spin down. The measuring device just indicates the true pure state of the particle.
But more normally, the particle is not in a pure state but is in some sort of superposition of up and down states. This case is illustrated in the 2nd happen of the diagram below. Now when the particle in a superposition of states approaches the measurement device what happens? According to the Copenhagen theory the wavefunction collapses and we measure either spin up or spin down. All of this is in strict accordance with the observational evidence. But we are left wondering what the measurement process was and what the collapse of the wavefunction means. According to the Multi-Worlds theory, the wavefunction just continues as a superposition, but this time it branches into one world where the superposition is of measuring instrument and spin up and another world with superposition of measuring instrument and spin down. Just that simple! Hmm, we will have to keep reading and studying, but it seems to make a lot of sense! There is yet much more in the book and I especially look forward to how space time emerges!
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| In "Things Deeply Hidden" this illustration introduces the Multi-World measurement process (Source: Palmia Observatory) |
Ok, ok, so there is more studying to be done, but it seems that the Everettian Many-worlds approach to quantum mechanics might actually not as crazy as it at first sounds. I need to keep reading the book and see. Time will tell! Check out your own copy and see if you don't agree.
Separately, after spending the morning trying to get a better understanding of the foundations of quantum mechanics, I met up with Visionary Physicist, Dr. Don, for a physics luncheon. We spent several hours discussing physics while I tried to gain better understanding with several margaritas. The topic that most caught my attention was the one dealing with nuclear isomers and how the gigantic energy storage potential of these materials could lead to vast improvements in energy storage density. They are reported to be able to store so much energy that 1 gram of isomeric material could store the equivalent of 315 kg of TNT. That is something like 100,000 times the energy storage density, in joules per gram, possible with ordinary chemical energy or lithium ion battery technology.
So, what is a nuclear isomer? For a quick introduction, check out the Wikipedia page: https://en.wikipedia.org/wiki/Nuclear_isomer
Wow, I had never heard of this property before. I knew that the nucleus could have discrete quantum energy levels but had not imagined the extent of how powerful the storage capability was. Thanks for enlightening me about that Dr. Don!
In the meantime, a nuclear isomer is when the nucleus of the atom can remain in higher than ground state energy levels for very long times. The quantum energy levels in the nucleus are just like those in the atomic energy levels of the electrons, where the discrete energy levels are on the order of several to a dozen electron volts, while the nuclear discrete energy levels are in the mega-electron volt (MeV) range. It takes a gamma ray of about 2.45 MeV to pump the nucleus up to a higher quantum energy level and when the nucleus drops back down to its ground state another 2.45 MeV gamma ray would be emitted. In the case of Hafnium 178, the half life of an excited nucleus is 31 years. Other isomers of Hafnium don't have this long life time of nuclear energy levels and they decay in fractions of a second and are not useful as energy storage materials.
So if you go through the back of the envelope calculations, which this physicist wannabe just did, of how many atoms would spontaneously drop back to its ground state, a gram of energized Hafnium 178 would radiate about 20 watts. So, it would get very hot and require special care when the material was in its charged state and special care would be needed for any type of energy storage product.
We can also go through some more back of the envelope calculations to see how far you could drive an electric car if you just started off with 1 gram of fully energized Hafnium 178? Well, given the half life of 31 years and average emission energy for each discrete energy level change of 2.45 MeV, I calculate, assuming say 50% system conversion efficiency and say, about 30 kwHr of electrical energy to drive 100 miles, then the 1 gram of energy storage should propel the car for about 600 miles. Wow, that could be really impressive! Also, the Hafnium is not used up and only needs to be recharged and used again. However, we haven't even begun to talk about the rest of the needed energy storage system components.
Keep in mind that even though this process involves the nucleus of an atom, it does not naturally come in the pre-charged state. The atom as it occurs in nature will be in the ground low energy state. It is not like a piece of coal or a gallon of gasoline, which already has stored energy there. So you would charge up the energy storage system by flooding it with 2.45 MeV gamma rays. That is going to be difficult to du and will require some big accelerator running from another power source. Hmm, is it a big accelerator or not? How hard is it to use electricity to power an accelerator to make 2.45 MeV gamma ray photons?
Ok, so if we assume the Hafnium is all charged up, how do we get more of the energy out more quickly that the 20 watts that just comes out spontaneously? The secret is to bombard the Hafnium with an x-ray photon. Hmm, well at least it is easier to build an x-ray source than it is to build a gamma ray charging source. The x-ray triggers the atom that receives the photon to fall back into its ground state and emit a 2.45 MeV gamma ray in the process. This effect is outlined in the figure below.
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| Example of triggering nuclear isomers (Source: Ed Hartouni, LLNL, "As assessment of Nuclear Isomers...") |
So we can control the rate at which the gamma rays are emitted by controlling the rate at which x-rays are injected into the Hafnium So this could be a very dense energy storage device technology. Two problems have been noted however. First of all the energy is released as 2.45 MeV photons and it is not known how to efficiently use this high energy gamma ray and convert it into the lower voltage needed for say an electrically powered vehicle. The second problem is what would happen if you sent a huge number of x-ray photons into the Hafnium and caused all of the atoms to spontaneously drop back to their ground state and emit all of the gamma rays at once. Wow, ok, that is what you would call making a bomb! This means the 1 gram of Hafnium would now release as much energy as 315 kg of TNT as mentioned earlier. This bomb would not rely on fission of uranium and would not release any of the normal radioactive byproducts associated with normal nuclear weapons.
Hmm, so even though the energy storage density of this technology would be huge, it does not seem likely that this kind of technology is going to be coming anytime soon. You can do your own internet search and see if you find any later findings and discussion about how all of this is actually working out.
Until next time,
Resident Astronomer George
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