Incoming links: University of Cambridge
Contains the University of Cambridge, that's about it really, from that everything follows.
The city appear to exist there because it was a convenient crossing of the Cam. It also lies near the start of the ancient navigable section TODO towards north or south? Castle hill also offered a convenient fortification location near the river, and is part of the reason for the early Roman settlement. The original bridge was presumably in the current Magnalene bridge, just under the castle hill.
TODO why did the University of Oxford scholars flee to after the The hanging of the clerks in 1209? Why not anywhere else?
Quick facts:
- Nationalities: Italian and Brazilian
- Grew up in: Brazil
- Relationship status 2017-: married
- Given name pronunciation: take your pick from Ciro Santilli's given name
- Chinese name: 三西猴, means "three western monkeys". Phonetic approximation to SANtilli CIRO. More info at: Ciro Santilli's Chinese name. Semi-unintentionally reminds Chinese people of Sun Wukong (孙悟空). This association is further slightly strengthened by the phonetic choice of 三 San, which Ciro later noticed matches the middle character of Tang Sanzang (唐三藏), the monk in Journey to the West. The given name 西猴 was given by Ciro Santilli's wife, then recent girlfriend, as a semi-joke, and he took it up because the best way to take a joke is to play along with the joker. 三 was chosen by Ciro himself.
- laptop: high end Lenovo ThinkPad
- distro: latest Ubuntu release
- Vim or Emacs: vi/vim. But for The Love, will someone please make an open source C++ integrated development environment that actually just works?
- tabs or spaces: spaces
- Mailing list or Git(Hub|Lab>): Git(Hub|Lab), with passion, see Section "Mailing list"
- system or unit tests: system
- programming languages: Python and C++. He'll learn Rust and Haskell once he's rich. As of the 2020s, Rust was picking up some serious steam, so Ciro might end up eating his own words there.
- musical instruments to listen: Chinese Guqin and electric Jazz-fusion guitar
- metric or imperial: metric, for The Love. Science? Standardization? 21st century anyone?
- QWERTY or Dvorak: QWERTY, alas
- birth name: Ciro Duran Santilli
Other people with the same name are listed at Section "Ciro Santilli's homonyms".
19th century illustration of the Journey to the West protagonist Sun Wukong
. Source. Sun Wukong (孙悟空) is a playful and obscenely powerful monkey Journey to the West. He protects Buddhist monk Tang Sanzang, and likes eating fruit, just like Ciro. Oh, and Goku from Dragon Ball is based on him. His japanese name is "Sun Wukong" (same Chinese characters with different Japanese pronunciation) for the love. His given name "Wukong" means literally "the one who mastered the void", which is clearly a Dharma name and fucking awesome in multiple ways. This is another sad instance of a Chinese thing better known in the West as Japanese.
It is worth noting however that although Wukong is extremely charming, Ciro's favorite novel of the Four Great Classic Novels is Water Margin. Journey to the West is just a Monster of the Week for kids, but Water Margin is a fight for justice saga. Sorry Wukong!
The photo was taken in an open event organized by the awesome Cambridge Synthetic Biology outreach group, more or less the same people who organize: www.meetup.com/Cambridge-Synthetic-Biology-Meetup/ and who helped organize Section "How to use an Oxford Nanopore MinION to extract DNA from river water and determine which bacteria live in it".
Taking part in such activities is what Ciro tries to do to overcome his lifelong regret of not having done more experimental stuff at university. Would he have had the patience to handle all the bullshit of the physical word without going back to the informational sciences? Maybe, maybe not. But now he will probably never know?!
Notice the orange high visibility cycling jersey under the lab coat, from someone who had just ridden in from work as fast as possible as part of his "lunch break". It is more fun when it is hard.
Scribe Jean Miélot, 15th century
. Ciro Santilli fantasises that he would have make a good scribe in the middle ages, partly due to his self diagnosed graphomania, but also appreciation for foreign languages, and his mild obsession with the natural sciences.
OurBigBook.com is Ciro's view of a modern day scriptorium, except that now the illuminations are YouTube videos.
Chill and eat your bread in peace comes to mind. A scribe, in a library, reading and writing the entire day in peace and quiet. The life!
The job of a Internet-age scribe is basically that of making knowledge more open, legally extracting it from closed copyrighted sources, and explaining your understanding of it to the wider world under Creative Commons licenses on the web. And in the process of greater openess, given a well organized system, we are able combine the knowledge of many diffferent people, and thus make things more understandable than any single/few creator closed source source could ever achieve.
Ciro once saw some cartoon on Wikipedia help pages of a turtle with a book in one hand, and typing into Wikipedia on its computer, TODO find it. That cartoon summarizes well the modern scribe life.
Another analogous version of this fantasy more in touch with Ciro's sinophily is the ideal of the Chinese scholar, notably including their stereotypical attributes such as mastery of the Four arts.
Ciro Santilli piling boxes as a child
. A natural born engineer.A charismatic, perfect-English-accent (Received Pronunciation) physicist from University of Cambridge, specializing in quantum field theory.
He has done several "vulgarization" lectures, some of which could be better called undergrad appetizers rather, a notable example being Video "Quantum Fields: The Real Building Blocks of the Universe by David Tong (2017)" for the prestigious Royal Institution, but remains a hardcore researcher: scholar.google.com/citations?hl=en&user=felFiY4AAAAJ&view_op=list_works&sortby=pubdate. Lots of open access publications BTW, so kudos.
The amount of lecture notes on his website looks really impressive: www.damtp.cam.ac.uk/user/tong/teaching.html, he looks like a good educator.
David has also shown some interest in applications of high energy mathematical ideas to condensed matter, e.g. links between the renormalization group and phase transition phenomena. TODO there was a YouTube video about that, find it and link here.
Ciro Santilli wonders if his family is of East Asian, origin and if he can still speak any east asian languages. "Tong" is of course a transcription of several major Chinese surnames and from looks he could be mixed blood, but as mentioned at www.ancestry.co.uk/name-origin?surname=tong it can also be an English "metonymic occupational name for a maker or user of tongs". After staring at his picture for a while Ciro is going with the maker of tongs theory initially.
This book series appears to be the one: global.oup.com/academic/content/series/h/history-of-the-university-of-oxford-huo/. A mere 250 pounds+ each.
History of Oxford University by Chris Day (2018)
Source. A large part of the video talks about how the insane system of colleges of the University of Oxford came about organically.- youtu.be/uol4V1Wa8B0?t=343 at the University of Bologna, the original system was for students to decide what they would learn, and hire and fire teachers as they decided. This is opposed to the system of the university of Paris, in which teachers make the final decisions. He mentions that this is the system that the University of Oxford and the University of Cambridge use: the "congregation". He mentions that Oxbridge are one of the few universities that maintained this structure (as opposed to having funding sources select the final decision makers)
- youtu.be/uol4V1Wa8B0?t=1327 mentions the quadrangle architecture which served as the basis of the Colleges: make a closed square with everything students need: Chapel, Hall to eat, classes and accommodation. This is based of course on monastic cloisters.
Cute simple paper-cut stop motion animations videos by Mithuna Yoganathan, a PhD in theoretical physics at the University of Cambridge: www.damtp.cam.ac.uk/person/my332.
This has the seeds of direct good intuition, but often stops a bit too short. Worth a look though, there is value in them for beginners.
No, they are basically not-for-profits, or more precisely in british legal terms, "charities". By taking government funding (directly or indirectly through subsiding enrolment fees?), they have to follow some government rules, and all major ones do it seems: academia.stackexchange.com/questions/49187/in-what-sense-are-uk-universities-public/49188
A similar confusing naming pattern appears to apply to Public school.
In the University of Cambridge for example, all MA degree holders or higher appear to have some voting power: www.cam.ac.uk/about-the-university/how-the-university-and-colleges-work/governance (archive)
This adds an extra layer of difficulty for the average taxpayer to make changes to university policy, e.g. making universities publish all material with Creative Commons licenses. At most, voters could require this indirectly through the government funding requisites. It is a mess.
Not even the Open University seems to be very open!
Ciro Santilli once attended a round table in the early 2020s where a University of Oxford official from the IP licensing department. The University of Oxford took a 20% equity on spin-off companies, not an uncommon University IP ownership policy at the time. At one point, the officer clearly justified this along the following very official sounding lines (paraphrased):While noble sounding, this immediately reminded Ciro of Instrumental convergence, in the field of AGI philosophy. Or in other words, of course the best approach to maximize education and research outcomes of society is to first take over the world, and then implement those goals from there! See also Why Not Just: Think of AGI Like a Corporation? by Robert Miles (2018)
The university is a charity with the goal of promoting education and research. All money obtained is reinvested in furthering education and research.
Notably, the University of Oxford was extremely protective of its learning material at that time, which was highly paywalled behind university logins, presumably with the rationale of having unique learning materials to enroll more paying undergrads. How can giving out free information to all not be the optimal way to "promoting education and research" is very hard to envision.
Bibliography:
- www.hepi.ac.uk/2023/06/07/most-universities-are-charities-so-what/ Most universities are charities: so what? by Mary Synge (2023) on the
Some possible/not possible sources that could be used to manually bootstrap content:
- LibreTexts. Good project. "Teacher-only-content" unfortunately as usual. But besides that fundamental flaw, they do exactly what we want to do in a sense.
- OpenStax: CC BY. This could be a great entry point, as they already have some university integration going on, and might be interested in this project.
- physics.stackexchange.com/questions/6157/list-of-freely-available-physics-books "List of freely available physics books" explicitly asks for:but the thread was locked, and basically none of the sources in the answers have free licenses, nor do they note it. It just seems that the physicists don't know what a free license is.
a list of physics books with open-source licenses, like Creative Commons, GPL
- MIT OpenCourseWare: CC BY-NC-SA, so not really usable
- github.com/certik/theoretical-physics: MIT License. Workable but wonky.
- subwiki.org/: wiki with some upper graduate math subjects presumably by this Indian dude: www.linkedin.com/in/vipul-naik-0ab1898/. Description on his homepage: vipulnaik.com/subwiki/. He's also got other interesting but not so relevant projects:He's also into Stack Overflow, Quora and Wikipedia editing. That's a cool dude. He's into in LessWrong it seems.
- pro freer immigration laws: vipulnaik.com/openborders/
- vipulnaik.com/cognito-mentoring/ free mentoring project for interested students
- massive mathematics books
- Infinite Napkin.CC BY-SA mathematics infinite book: github.com/vEnhance/napkin/issues/77. Very similar type of content to what we want in this project!
- Stacks Project
Existing lecture notes by students:
- github.com/mb2g17/NotesNetworkArchive Google Docs-based: docs.google.com/document/d/1OIcQ8dJ_FAhdkirU94M29-ZbNZ4oQs1LbWF3Nz-mq_U/edit#heading=h.vehxib58w1iw. An actual student uploading tons of lecture notes in one coherent system. CC BY-NC-SA unfortunately.
- academia.stackexchange.com/questions/148261/do-you-keep-your-study-notes-publicly-available mentions:Related: academia.stackexchange.com/questions/40381/how-common-is-it-that-professors-have-their-students-write-textbooks
- Cambridge Mathematics Lecture Notes by Dexter Chua (2014-2018)Comments:
Lecture note upload website:
- nexusnotes.com likely illegal reuploads of PDFs from teachers
- www.studocu.com/en-gb Paywall. PDF uploads. Unclear if simple teacher reuploads or actual novel notes.
- www.studydrive.net/
- Chinese GitHub repos. Some of these are very advanced in terms of content quantity and organizational quality! The Chinese are miles ahead in this area:
- github.com/PKUanonym/REKCARC-TSC-UHT Guidance for courses in Department of Computer Science and Technology, Tsinghua University. Chinese. Appears to try and store all past exams.
- github.com/lib-pku/libpku
- github.com/openwhu/OpenWHU: Wuhan University
- github.com/USTC-Resource/USTC-Course: USTC
- github.com/Zeal-L/UNSW: UNSW from Australia, but by a Chinese dude
- github.com/apachecn/mit-18.06-linalg-notes: translation of MIT course to Chinese
- github.com/chenyang1999/MyComputerCollegeCourses: TODO which univeresity
- github.com/elder-frog/OpenCourseCatalog: nothing to do with this project, but since I'm making a list, this dude is copying YouTube videos to Bilibili. And he's edgy anti-CCP on Twitter, what a legend.
- github.com/TheBloodthirster/BUAA_Course_Sharing: en.wikipedia.org/wiki/Beihang_University
- github.com/1051727403/SHU-CS-Source-Share: ShangHai University CS course source code
- github.com/Willie169/tw-gifted-k12-notes: Taiwanese high school notes
Exams uploads:
- questions.tripos.org/part-ib/all/ University of Cambridge Mathematics past examinations
PuntSeq is a side project led by a few University of Cambridge PhDs that aims to determine which bacteria are present in the River Cam.
In July 2019, the PuntSeq team got together with the awesome Cambridge Biomakespace, an awesome biology makerspace open to all, to create a two day science outreach activity showing their procedures.
The data collected in this experiment, together with other collection sessions done by the organizers actually led to a publication on eLife: elifesciences.org/articles/61504 "Freshwater monitoring by nanopore sequencing" by Lara Urban et al. (2021), so it is awesome to see that were are actual being part of "real science".
Ciro knows nothing about biology, but since he is very curious about it, he jumped at this opportunity, and decided to document things as well as his limited knowledge would allow.
All participants chipped in some money to help cover the experiment's costs. Ciro suspects that this activity was done partially to help crowdfund the experiment, but it was a worthy investment!
The impressions you get from the experiment as a software engineer will be:
- OMG, this is so labour intensive, why haven't they automated this
- OMG, this is frightening, all the 8 hours of work I've just done are present in that tiny plastic tube
- Amazing! Look at that apparatus! And the bio people are like: I've used this a million times, it's cheap and every lab has one, just work faster and don't break you piece of junk!
Eccentric nerdy slow speaking physicist mostly based in University of Cambridge.
Created the Dirac equation, what else do you need to know?!
QED and the men who made it: Dyson, Feynman, Schwinger, and Tomonaga by Silvan Schweber (1994) chapter 1.3 "P.A.M. Dirac and the Birth of Quantum Electrodynamics" quotes Dirac saying how being at high school during World War I was an advantage, since all slightly older boys were being sent to war, and so the younger kids were made advance as fast as they could through subjects. Exactly the type of thing Ciro Santilli wants to achieve with OurBigBook.com, but without the need for a world war hopefully.
Dirac was a staunch atheist having said during the Fifth Solvay Conference (1927)[ref]:
If we are honest - and scientists have to be - we must admit that religion is a jumble of false assertions, with no basis in reality. The very idea of God is a product of the human imagination. It is quite understandable why primitive people, who were so much more exposed to the overpowering forces of nature than we are today, should have personified these forces in fear and trembling. But nowadays, when we understand so many natural processes, we have no need for such solutions. I can't for the life of me see how the postulate of an Almighty God helps us in any way. What I do see is that this assumption leads to such unproductive questions as why God allows so much misery and injustice, the exploitation of the poor by the rich and all the other horrors He might have prevented. If religion is still being taught, it is by no means because its ideas still convince us, but simply because some of us want to keep the lower classes quiet. Quiet people are much easier to govern than clamorous and dissatisfied ones. They are also much easier to exploit. Religion is a kind of opium that allows a nation to lull itself into wishful dreams and so forget the injustices that are being perpetrated against the people. Hence the close alliance between those two great political forces, the State and the Church. Both need the illusion that a kindly God rewards - in heaven if not on earth - all those who have not risen up against injustice, who have done their duty quietly and uncomplainingly. That is precisely why the honest assertion that God is a mere product of the human imagination is branded as the worst of all mortal sins.
Paul Dirac and the religion of mathematical beauty by Royal Society (2013)
Source. www.quora.com/Is-MIT-the-only-place-where-homework-is-called-problem-sets
Terminology by location:
Places that say "problem set":Places that say "problem sheet":Places that say "example sheet":
Terminology by location:
Places that say "problem set":Places that say "problem sheet":Places that say "example sheet":
- University of Cambridge. Source: www.inference.org.uk/sanjoy/teaching/corpus/
Mechanics/Molecules (Fall term) example sheets (Cambridge jargon for problem sets)
Author: David Tong.
Number of pages circa 2021: 155.
It should also be noted that those notes are still being updated circa 2020 much after original publication. But without Git to track the LaTeX, it is hard to be sure how much. We'll get there one day, one day.
Some quotes self describing the work:
- Perhaps for this reason Ciro Santilli was not able to get as much as he'd out of those notes either. This is not to say that the notes are bad, just not what Ciro needed, much like P&S:This is a very clear and comprehensive book, covering everything in this course at the right level. To a large extent, our course will follow the first section of this book.
In this course we will not discuss path integral methods, and focus instead on canonical quantization.
A follow up course in the University of Cambridge seems to be the "Advanced QFT course" (AQFT, Quantum field theory II) by David Skinner: www.damtp.cam.ac.uk/user/dbs26/AQFT.html
This is one of the prime examples of Europe's decline.
Instead of trying to dominate the sequencing market and gain trillions of dollars from it, they local British early stage investors were more than happy to get a 20x return on their small initial investments, and sold out to the Americans who will then make the real profit.
And now Solexa doesn't even have its own Wikipedia page, while Illumina is set out to be the next Microsoft. What a disgrace.
Here are some good articles about the company:
Cambridge visitors can still visit the Panton Arms pub, which was the location of the legendary "hey we should talk" founders meeting, chosen due to its proximity to the chemistry department of the University of Cambridge.
In 2021 the founders were awarded the Breakthrough Prize. The third person awarded was Pascal Mayer. He was apparently at Serono Pharmaceutical Research Institute at the time of development. They do have a wiki page unlike Solexa: en.wikipedia.org/wiki/Serono. They paid a 700 million fine in 2005 in the United States, and sold out in 2006 to Merck for 10 billion USD.
Ciro Santilli is actively looking for donations and contracts so he can continue to work full time on OurBigBook.com sustainably, and develop free hardcore university-level STEM education for all ages!
At 100k USD, I quit my job to work full time on it for one year. During this year I will use my contacts with STEM students of a world leading university near where I live and solve as many of their problem sheets as possible, mostly by referring to OurBigBook.com articles I'll be writing. The goal is to get as much STEM knowledge as possible into the world, and highlight how flawed presencial and sequential Higher Education is, while positioning OurBigBook.com as an alternative way to organize humanity's knowledge. Quite grand.
Status: ~144k / 200k USD reached. 1st year locked in and started 1st June 2024 to 31st May 2025[ref], 2nd year stretch goal open. A second year greatly improve chances of success: year one I solve a bunch of courses, year two I come guns blazing with the content and expand further. Donation breakdown:More details: Section "Accounting method"
- 2024-03-18: $126,352 (!!!): anonymous 1000 Monero donation to self-custody wallet. Further comments: 1000 Monero donation.
- 2024-03-13: $1,375: anonymous 10 Monero donation to self-custody wallet
- 2023-11-20: $14.563: anonymous 100 Monero donation to Binance wallet
- 2023-09: $810: anonymous 0.032 Bitcoin donation to Coinbase wallet
- subscriptions up to 2024-01: $143,795
At 1M USD I retire and work on open STEM education forever.
Note to potential anonymous crypto donors: anonymous donations incur a regulatory risk. I cash out most of such donations and announce it very clearly to the government and banks. For example, at one point Barclays even froze my UK account. But things seem manageable for now. On one hand, such donations serve as a fun test of the financial system. But on the other, if all banks reject my money or if the government decides to take it, I will write off the anonymous donation at zero.
How to give:And if you have a different preferred payment mechanism not listed above, please contact Ciro, and he will set it up.
- one time donations:
- cryptocurrency: note that Ciro is not a regular crypto user, so you might want to make a smaller test donation and confirm that it worked by contacting Ciro before going for colossal amounts (one can dream):
- Monero address: 4A1KK4uyLQX7EBgN7uFgUeGt6PPksi91e87xobNq7bT2j4V6LqZHKnkGJTUuCC7TjDNnKpxDd8b9DeNBpSxim8wpSczQvzf. Secret view key: 7ccaf885ff5540b0ff18927e6ac5da30130afb1eaee09ad95d3c4536a6337e0f. This is a self-custody wallet on a "clean" dedicated Monero laptop connected the Internet. I check for incoming transactions from my dirty main laptop via a view-only wallet each weekend. The cash out method used is latest simplest thing that wasn't yet blocked in my country on a given week, the last time that was centralized swappers[ref]. The fact that the cash out method changes weekly confirms that Monero privacy hadn't yet been broken by countries and that Monero is still one of the most useful cryptocurrencies: Section "Are cryptocurrencies useful?". For transparency, I announce all non-trivial transactions on social media, and the full list of transactions can be seen by anyone with the secret view key provided. I previously had different addresses, so pre-existing donations on older addresses will not be visible there.
- Bitcoin address: 3KRk7f2JgekF6x7QBqPHdZ3pPDuMdY3eWR. This is a Coinbase wallet, off-chain transactions with no transaction fees accepted from other Coinbase users. This method has been tested, I have been able to receive funds from this address in 2023. Fees: non-fixed trading fees[ref] + 0% withdrawal fee on top of any Bitcoin network for on-chain transactions[ref]
- Ethereum address: 0x44cF8C9C015F46d3b2Df730b6492823FD7A91044. Test transaction recommended.
- Solana address: DjdaGawoVFdqxJEqpBGsSWuR4G4MVFNiNkAEu89HuKcE. Test transaction recommended.
- TransferWise tag: wise.com/pay/me/cirod3. It shows as "Ciro Duran Santilli" and that's correct. No fees apparently? Love it!
- PayPal: paypal.me/cirosantilli. Note that dots in Gmail address are ignored, and it is perfectly normal if the email you see has some extra dots in it. Fees: 2.9% + 0.30 GBP[ref].
- cryptocurrency: note that Ciro is not a regular crypto user, so you might want to make a smaller test donation and confirm that it worked by contacting Ciro before going for colossal amounts (one can dream):
- monthly subscriptions of 1$/month or more on either:Symbolic 1 dollar/month donation are extremely welcome to signal your interest! This way if a certain critical mass of sponsors is ever reached (~100?), Ciro can start to more actively asking slightly higher amounts to really try to achieve full time self sufficiency.
- GitHub Sponsors: github.com/sponsors/cirosantilli. Fees: 0% for individuals, up to 6% for organizations[ref]
- Patreon: www.patreon.com/cirosantilli. Fees: 8% pro plan + 1% PayPal withdrawal capped at 20 USD[ref]. We are waiting to reach the cap to withdraw!
- larger grants/contracts from filthy rich individuals or organizations: contact Ciro as mentioned at: Section "How to contact Ciro Santilli" to discuss.Ciro is interested in contracts/voluntary work that would be compatible/synergic with the OurBigBook.com project. Some possibilities include:
- interacting directly with classes of university students to help them learn the class subject, while at the same time spreading the university knowledge outside of the university walls
- one-to-one mentoring of individuals of any age that are looking to make an impact in the world, and not just pass their exams
- fixing specific bugs in related projects Ciro has experience in. These could be either via one-off contracts, or on platforms such as:
Ciro's current ambitions require him to remain in developed countries, because Ciro wants to document advanced science and technology by liaising with top universities, and there is not nearly as much high technology in poor countries. Remaining in developed countries is also a required due to family reasons.
If you would like public acknowledgement for your support, Ciro will very gladly give it, just let Ciro know how you'd prefer it. Due to Ciro Santilli's campaign for freedom of speech in China, many supporters have chosen to be anonymous, and that is totally fine, not everyone is interested in politics, or has a situation where going public is acceptable, so we don't have a standard setup yet, let's build it together. A acknowledgement section at the bottom of this page would be a minimum, but I for larger donations we could add a your advertisement in a locations such as:
- near the top of of the accounts controlled by Ciro Santilli, e.g. one of Ciro Santilli's Twitter accounts, github.com/cirosantilli or stackoverflow.com/users/895245
- near the top of cirosantilli.com
100k USD/year is a semi arbitrary amount that sounds nice. My last day job total compensation as of 2024 was about 150k USD/year.
Intro to the OurBigBook Project
. Source. Maybe if he ever gets enough credibility, such opportunities would actually materialize. It could be a bit like Periodic Videos, but for molecular biology and physics, and backed by OurBigBook text/tree with minimal openly licensed videos. The fact that such opportunities are essentially impossible outside of the boredom of the university system is something we should really change about education.
Applications: produce high magnetic fields forAs of the early 2020s, superconducting magnets predominantly use low temperature superconductors Nb-Ti and Nb-Sn, see also most important superconductor materials, but there were efforts underway to create practical high-temperature superconductor-based magnets as well: Section "High temperature superconductor superconducting magnet".
- Magnetic resonance imaging, the most important commercial application as of the early 2020s
- more researchy applications as of the early 2020s:
Wikipedia has done well for once:
The current to the coil windings is provided by a high current, very low voltage DC power supply, since in steady state the only voltage across the magnet is due to the resistance of the feeder wires. Any change to the current through the magnet must be done very slowly, first because electrically the magnet is a large inductor and an abrupt current change will result in a large voltage spike across the windings, and more importantly because fast changes in current can cause eddy currents and mechanical stresses in the windings that can precipitate a quench (see below). So the power supply is usually microprocessor-controlled, programmed to accomplish current changes gradually, in gentle ramps. It usually takes several minutes to energize or de-energize a laboratory-sized magnet.
Superconductivity: magnetic separation by University of Cambridge
. Source. University of Cambridge students, CanTabBridgeans.
- 1859-1900: see Section "Black-body radiation experiment". Continuously improving culminating in Planck's law black-body radiation and Planck's law
- 1905 photoelectric effect and the photon
- TODO experiments
- 1905 Einstein's photoelectric effect paper. Planck was intially thinking that light was continuous, but the atoms vibrated in a discrete way. Einstein's explanation of the photoelectric effect throws that out of the window, and considers the photon discrete.
- 1913 atomic spectra and the Bohr model
- 1885 Balmer series, an empirical formula describes some of the lines of the hydrogen emission spectrum
- 1888 Rydberg formula generalizes the Balmer series
- 1896 Pickering series makes it look like a star has some new kind of hydrogen that produces half-integer entries in the Pickering series
- 1911 Bohr visits J. J. Thomson in the University of Cambridge for his postdoc, but they don't get along well
- Bohr visits Rutherford at the University of Manchester and decides to transfer there. During this stay he becomes interested in problems of the electronic structure of the atom.Bohr was forced into a quantization postulate because spinning electrons must radiate energy and collapse, so he postulated that electrons must somehow magically stay in orbits without classically spinning.
- 1913 february: young physics professor Hans Hansen tells Bohr about the Balmer series. This is one of the final elements Bohr needed.
- 1913 Bohr model published predicts atomic spectral lines in terms of the Planck constant and other physical constant.
- explains the Pickering series as belonging to inoized helium that has a single electron. The half term in the spectral lines of this species come from the nucleus having twice the charge of hydrogen.
- 1913 March: during review before publication, Rutherford points out that instantaneous quantum jumps don't seem to play well with causality.
- 1916 Bohr-Sommerfeld model introduces angular momentum to explain why some lines are not observed, as they would violate the conservation of angular momentum.