Comment on Persistent luminescence instead of phosphorescence
https://www.researchgate.net/publication/327939317_Persistent_luminescence_instead_of_phosphorescence_History_mechanism_and_perspective/comments
Enjoyable read with many thoughtful ideas and descriptions. There are several energy sources for these photon flows, but thermal energy harvesting over long periods, then optical photon emission for shorter periods seems to be the theme. The energy stored in electronic states.
I am posting this on 18 Apr 2021:
“persistent luminescence” has 85,700 entry points
(“afterglow” OR “after-glow”) (“photon” OR “emission” OR “spectrum”) has 1.19 Million entry points
“phosphorescence” has 2.35 Million entry points
(“gamma emitter” OR “gamma emitters”) has 129,000 entry points
(“luminescent” OR “luminescence”) (“photon” OR “emission” OR “spectrum”) has 28.3 Million entry points (but these have primarily external energy source, not energy stored in the material)
An energy harvester then using the stored energy to make light is not part of the game, unless it is a bulk effect. Exchanging one higher frequency photon for a few smaller ones (amplifies the effectiveness of the initial storage by spending at a slower rate) seems to be fair. But stored energy from creation of a radioactive material that supplies energy for photoemission is not.
It was a long paper. I do not remember reading if you allow for electron fluctuations, or acoustic fluctuations as “emission”. A hot body will have higher electronic noise until it cools off. A stressed body will have higher energy for stress relief events until that stress is relieved.
Now Barkhausen noise is driven by magnetic energy storage. And, yes indeed:
“persistent” “barkhausen” has 94,700 entry points
“pinning field” has 17,400 entry points
I think that “fast storage and slow decay” covers SSD devices. They all decay over time. It is a serious problem solved mainly by continuous refreshing of the stored data. So all memory devices today have some decay, usually microstructural and tied to manufacturing defects or “lucky cells”.
Is an active device fair? Charge management and pumping is fairly sophisticated now. Store the charge now, and later leak it out slowly. “Low power” “optical” is big business these days. So if you can make reliable photoemission centers with programmable features, is it “cheating” to have it manufactured or some meta-material?
During earthquakes and subduction and volcanic events piezoelectric and piezomagnetic events are triggered. There is some evidence these massively parallel events show up in the very low frequency electromagnetic sensor networks. Many pressure events triggered in parallel looks like a slow electromagnetic event.
So if you sat on a piezoelectric or piezomagnetic material and it later had some way to leak out that energy by magnetic domain events or photo emission or even low frequency electromagnetic? Would that be fair?
Now I have been interested in low frequency electromagnetic signals most of my life. And I saw in recent years that piezoelectric materials can be driven by electric currents to give off very low frequency electromagnetic waves. You are probably old enough to remember those massive antennas for submarines.
So if one of those kinds of devices was pressed and then later gave off a slow electromagnetic groan of a signal. Would that be fair?
If you are going to build a global community to combine those many phenomena and efforts, I will be blunt. Sticking all that hard work into a PDF file is about the worst thing you can do. It is long, complex, jargon-filled, and NONE of it is easily extracted, traced or usable from that format. Yes, I know, you are used to spending decades doing things. It would be nice if the young people wanted to devote their lives to things like gathering and organizing knowledge. But they would rather throw stuff into their machine learning algorithms and hope for a gem or two. I think there is a balance between prospecting for gold and serious scholarship, and commercialization and the needs of society.
Maybe I am biased because I spent time recently reviewing all memory device technologies to see what else they might be used for. Memory devices that decay slowly (NAND memory, “floating gate” MOSFET, others) could be seeded with nanodots that emit light. Would that be fair?
What about ordinary batteries, supercapacitors, ultracapacitors? Is that cheating? They certainly are bulk devices, or would like to be, and they are already hooked up to electronic controls and devices. They just need low power light emitters. So if someone told me that it had to be powered by the sun or heat, and only from bulk chemical processes, I would ask who is buying it, and do they care?
A “global community” in my world of the Internet means a group of people working on the Internet with tools to share anything. Not words on paper that require years or forever to transcribe back to reality. But models, data, algorithms, test processes, projects and plans that are living and aimed at global goals and purposes. So I kind of hate PDF right now. I see its worst devastation on things like covid and all global research efforts. Share the same material in models that really work, in visualizations and simulations that work and anyone can see and change the values or data. Share the development with algorithm (including both mathematical symbolic and computer representations and some “machine learning AI understand human language or can figure it out themselves” kinds of groups.
What you really have to do is reach deep in your heart and decide what it is you want to do next. I read about those things you wrote over most of my life. They are familiar and comforting. But I am pretty sure the kids want to move to the moon or Mars and I don’t think I am young enough to follow them. But I might be able to help them anticipate and solve some of the things I know they will face.
My Dad is gone now for a while. Before he died he told me about a dream he had one night. In the dream he had died and gone to heaven. But he was never pushy, so when they said he was accepted to heaven, they ask him what did he want to do? He said something like, “I don’t know, do you have any suggestions?” So they gave him a job washing dishes at the very edge of heaven. He would never run out of dishes to wash, so he had some tiny bit of self worth from doing something useful. And he had a small window to look out to see various “heavenly” things so he was not completely left out. That was all he told me, so I don’t know if they sleep and take breaks. He did not say what he could see. This is a guy on a Navy destroyer when WWII ended down inside a boiler cleaning it out. So he did not even hear until later that it was over. You do you little part, and hope that it was all worthwhile.
I know from studying Internet groups for the last 30 years almost continuously that you can do a lot better than posting PDF files that humans, very specialized humans are needed to read and use it. If you break it up into interchangeable parts, and then combine all the different parts into interlocking groups, then all research is part of one whole. Worried about not having enough to do? There are are many thousands of times more problems NOT solved than ones that have been commercialized. That is a limitation because of human greed and vision, not because there is not a lot to do.
When I was at UT Austin, Ilya Prigogine was there and everyone was working on chemical oscillators. Those bulk chemical solutions would oscillate for quite long periods. If you can solve coupled differential equations or process models, then it should not be too hard to solve for bulk reaction that have (1) slow decays releasing light (2) time delays and then release (3) oscillatory or chaotic light release. There is no difference except labels between those reaction networks and electrical circuits. If you let the kids use digital methods, then you don’t have to play games where the only tools you use are “chemical” or someones favorites. I have lots to do. I wish I had more time. But when I was there learning about chemical clocks and statistical mechanics, I was also following the fusion work, and that finally made the turn to move ahead. So yet another group to follow and see what they have done.
You know very well the limitations of this kind of review and sharing. You have more than the average number of papers. Did you see those numbers above? That is what I do every day for that last 23 years. Tens of thousands of topics and the groups and resources, industries products services, education and jobs and retraining and investments — that make each topic a global community. It is possible to review the whole Internet. A few million or a few hundred million entry points is not daunting or impossible. Our kids have to live in that kind of world where you are not competing with a few dozen kids in a class, or a few thousand in a school, but with a big chunk of the 7.8 Billion humans on the eart now, and many many new algorithms that are slowly reaching job taking levels of competence.
Richard Collins, Director, The Internet Foundation
