Manne Siegbahn was a prominent Swedish physicist known for his work in the field of spectroscopy and experimental physics. Born on December 3, 1886, he made significant contributions to the understanding of X-ray spectroscopy and radiation. Siegbahn was awarded the Nobel Prize in Physics in 1924 for his research on the diffraction of X-rays and the development of new spectroscopic techniques.
Pierre Janssen, full name Pierre Jules César Janssen, was a French astronomer born on February 22, 1824, and he passed away on December 23, 1907. He is best known for his contributions to the field of spectroscopy and for his role in the discovery of the element helium. One of his significant achievements was the observation of a solar prominence during a total solar eclipse in 1868.
Rudolf Mössbauer was a German physicist best known for the discovery of the Mössbauer effect, a physical phenomenon involving the recoil-free emission and absorption of gamma rays by atomic nuclei. This effect, which he discovered in 1958, allows for extremely precise measurements of nuclear energy levels and has important applications in various fields, including physics, chemistry, and biology.
As of my last update, there is no widely recognized figure or entity named Shelby G. Tilford in public databases, historical records, or notable literature. It's possible that Shelby G. Tilford could be a private individual, a lesser-known figure, or a fictional character. If you have more specific context or details regarding Shelby G.
William Huggins (1824–1910) was a prominent English astronomer known for his pioneering work in astrophysics. He is particularly noted for his contributions to the study of spectroscopy, which is the analysis of the light emitted or absorbed by materials. Huggins was one of the first astronomers to apply spectroscopy to the study of celestial bodies, helping to determine their composition, temperature, and motion.
And that is the whole point.
The outcome of that however is that you have to learn how to explain what you've achieved to others and why it is awesome.
Just like in the real world.
You have to create portfolio, and do some public relations.
Notably used for communication with submarines, so in particular crucial as part of sending an attack signal to that branch of the nuclear triad.
arstechnica.com/information-technology/2016/11/private-microwave-networks-financial-hft/ The secret world of microwave networks (2016) Fantastic article.
How Microwaves Work by National MagLab (2017)
Source. A bit meh. Does not mention the word cavity magnetron!How a Microwave Oven Works by EngineerGuy
. Source. Cool demonstration of the standing waves in the cavity with cheese! What poor countries have to do to get richer Make your education system more efficient by 
Ciro Santilli 40 Updated 2025-07-16
Ciro Santilli 40 Updated 2025-07-16As Ciro has rambled infinitely at Section "University", the school system is hugely inefficient and a waste of time for everyone involved.
Instead, just use Section "OurBigBook.com" instead.
One of Ciro Santilli's strongest feeling in education is that material often falls in either of the two categories:
- hundreds of too basic popular science, e.g.:
- a 5 minute popular science video trying to explain quantum electrodynamics (an advanced subject) for someone who doesn't know what a Riemann integral is (a basic subject)
- a few full university courses that takes 20 hours to deliver the first punchline of the course
Ciro believes that there is often an important missing link between them, e.g.:
If we as a society are unable to provide this sweet Middle Way sweet-spot, it is unreasonable to expect that learners will ever have the motivation to advance, because it is just too boring! They are just more likely to go play video games instead.
It is Ciro's hope that OurBigBook.com will help to fill exactly that gap.
In Ciro's view, as of the 2020's this critical gap generally lies somewhere between the end of undergraduate studies, and at the start of postgraduate studies.
Let's take the gloves off more often, and give the full thing to interested students! Let students learn what they want to learn, and do that as soon as possible! Life is too short!
This problem is basically the knowledge version of the last mile problem. When we reach the end of graduate, there are enough directions of knowledge to go off into, that the probability that a great free tutorial exists is relatively low. Of course, as one approaches the realm of novel research, the branching is so wide that having perfect tutorials becomes impossible. Ciro's goal in life go push the last mile marker a bit further out.
Related:
- universityphysicstutorials.com/ by Adam Beatty mentions:
There are myriad resources for physics and maths. The Kahn Academy and Patrick JMT were the best for me. They really helped me out. The question is, what resources are there for the advanced undergraduate courses?
In this video, the noted chemist mentions how he managed to get into a chemistry research development before he even joined university, due to a somewhat exceptional situation. Section "The only reason for universities to exist should be the laboratories" also comes to mind. This is exactly the type of thing that Ciro Santilli wants to make much more widespread.
Stories of Ainan Celeste Cawley fighting to advance his kids education beyond school, and being forbidden to do so by a stupid educational system, also come to mind.
Bibliography:
Experimental setup to observe radiation pressure in the laboratory.
Application of radiation pressure.
First live example: en.wikipedia.org/wiki/IKAROS
You can then detect one of the photons, and when you do you know that the other one is there as well and ready to be used. two photon interference experiment comes to mind, which is the basis of photonic quantum computer, where you need two photons to be produced at the exact same time to produce quantum entanglement.
Features Alan Migdall of the National Institute of Standards and Technology. Produced by the Joint Quantum Institute (JQI).
Mentions that this phenomena is useful to determine the efficiency of a single photon detector, as you have the second photon of the pair as a control.
Also briefly describes how the input energy and momentum must balance out the output energy and momentum of the two photons coming out (determined by the output frequency and angle).
Shows the crystal close up of the crystal branded "Cleveland Crystals Inc.". Mentions that only one in a billion photon gets scattered.
Also shows a photomultiplier tube.
Then shows their actual optical table setup, with two tunnels of adjustable angle to get photons with different properties.
Very short whiteboard video by Peter Mosley from the University of Bath, but it's worth it for newbs. Basically describes spontaneous parametric down-conversion.
One interesting thing he mentions is that you could get single photons by making your sunglasses thicker and thicker to reduce how many photons pass, but one big downside problem is that then you don't know when the photon is going to come through, that becomes essentially random, and then you can't use this technique if you need two photons at the same time, which is often the case, see also: two photon interference experiment.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
Figure 5. Web editor. You can also edit articles on the Web editor without installing anything locally.Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact