Interesting to note that there are quite a few nearer than Sagittarius A, as of 2022 we know of one at 1.5 kly: universemagazine.com/en/discovered-the-closest-black-hole-to-the-sun/
It is interesting that a few months earlier there seemed to be no known specific black holes in the Milky Way: www.nasa.gov/feature/goddard/2022/hubble-determines-mass-of-isolated-black-hole-roaming-our-milky-way-galaxy although their count is estimated to be in the hundreds of millions.
A list of reviews of such systems is maintained at:
This is the class of existing software the perhaps comes the closest to OurBigBook, in particular systems such as:
- Roam Research and its open source clone Foam
- Forester
While we believe that OurBigBook can hold its own against most of them as a personal knowledge base, there is one feature which we believe truly distinguishes OurBigBook from all others in a big way: trustless mind meld with the OurBigBook topic feature, which no other system seems to have.
Many such systems are also no publishing focused enough, and are more focused only in maintaining people's private knowledge bases. Some of them don't even have publishing at all, or its complicated. While publishing is optional in OurBigBook, it is a crucial feature and extremely well supported.
Bibliography:
- Subtle is the Lord by Abraham Pais (1982) chapter III "Relativity, the special theory" has a good sketch as you may imagine.
- www.quora.com/How-is-a-voice-transmitted-from-one-phone-to-another
- www.quora.com/How-many-wires-does-a-telephone-use/answer/Peter-Yardley-1
Basic analogue phones connected to the public exchange use two wires mainly arranged as a twisted pair to reduce noise. The voice signal is differential (the voltage in one wire equal and opposite to the other) biased above ground by 48V. Using a twisted pair reduces induced noise because the noise signal will induce an equal voltage in each wire and because the signal is transmitted as the difference the effect of the induced noise will be dramatically reduced.
Phone Intercom by Make (2014)
Source. This video illustrates will the incredible simplicity of the connection of a telephone system. Compare that to the relative complexity of wireless communication, which requires modulation.A 2022 clone of phabricator.wikimedia.org/source/mediawiki.git gives first commits from 2003 by:
- Lee Daniel Crocker: en.wikipedia.org/wiki/Lee_Daniel_Crockerso that gives a good notion of the last major rewrite.
He is best known for rewriting the software upon which Wikipedia runs, to address scalability problems.
- Brion Vibber
TODO when was wikipedia open sourced from Nupedia? The ealry days of Wikipedia are quite obscure due to its transition from Nupedia.
The Klein-Gordon equation directly uses a more naive relativistic energy guess of squared.
But since this is quantum mechanics, we feel like making into the "momentum operator", just like in the Schrödinger equation.
But we don't really know how to apply the momentum operator twice, because it is a gradient, so the first application goes from a scalar field to the vector field, and the second one...
So we just cheat and try to use the laplace operator instead because there's some squares on it:
But then, we have to avoid taking the square root to reach a first derivative in time, because we don't know how to take the square root of that operator expression.
So the Klein-Gordon equation just takes the approach of using this squared Hamiltonian instead.
Since it is a Hamiltonian, and comparing it to the Schrödinger equation which looks like:taking the Hamiltonian twice leads to:
We can contrast this with the Dirac equation, which instead attempts to explicitly construct an operator which squared coincides with the relativistic formula: derivation of the Dirac equation.
The 1890 US Census and the history of punchcard computing by Stand-up Maths (2020)
Source. It was basically a counting machine! Shows a reconstruction at the Computer History Museum.It is quite mind blowing that this is polyphyletic on mammals and birds, what can't parallel evolution achieve??
Phylogenetic tree of the vertebrates
. Source. Highlights how birds should obviously be classified as reptiles.
What a material:
- only exists in trace amounts in nature,but it can be produced at kilogram scale in breeder reactors
- it is only intentionally produced for one application, and one application only basically: nuclear weapons
Burning and Extinguishing Characteristics of Plutonium Metal Fires by RobPlonski
. Source. Commented by this dude: www.linkedin.com/in/robplonski/Lit: fish timber question answer.
The dialog is also known as allegory for an incredibly deep philosophical discussion between an idealized wise woodcutter and a fisherman, e.g. mentioned at: www2.kenyon.edu/Depts/Religion/Fac/Adler/Writings/Fisherman%20and%20Woodcutter.pdf
This song is just too slow for Ciro Santilli to make much out of it.
Bibliography:
Dialog between Fisherman and Woodcutter Chinese traditional painting by Xie Shichen
. Dialog between Fisherman and Woodcutter uploaded by Fei Sun
. Source. Reaches 2 mK[ref]. youtu.be/upw9nkjawdy?t=487 from Video "Building a quantum computer with superconducting qubits by Daniel Sank (2019)" mentions that 15 mK are widely available.
Used for example in some times of quantum computers, notably superconducting quantum computers. As mentioned at: youtu.be/uPw9nkJAwDY?t=487, in that case we need to go so low to reduce thermal noise.
Sometimes systems of Diophantine equations are considered.
Problems generally involve finding integer solutions to the equations, notably determining if any solution exists, and if infinitely solutions exist.
The general problem is known to be undecidable: Hilbert's tenth problem.
The Pythagorean triples, and its generalization Fermat's last theorem, are the quintessential examples.
To avoid duplication when citing multiple pages: Section "How to use a single source multiple times in a Wikipedia article?"
A good big sample definition:There is also
<ref name="googleStory">{{cite book |last1=Vise |first1=David |author-link1=David A. Vise |last2=Malseed |first2=Mark |author-link2=Mark Malseed |title=The Google Story |date=2008 |publisher=Delacorte Press |url=https://archive.org/details/isbn_9780385342728}}</ref>title-link to link to a wiki page. But it is incompatible with url= for Internet Archive Open Library links which is a shame.Based on the fact that we don't have a P algorithm for the discrete logarithm of the cyclic group as of 2020, but we do have an efficient algorithm for modular exponentiation. But nor do we have proof that one does not exist! Living on the edge as usual for public-key cryptography.
Ultimate explanation: math.stackexchange.com/questions/776039/intuition-behind-normal-subgroups/3732426#3732426
Only normal subgroups can be used to form quotient groups: their key definition is that they plus their cosets form a group.
Intuition:
One key intuition is that "a normal subgroup is the kernel" of a group homomorphism, and the normal subgroup plus cosets are isomorphic to the image of the isomorphism, which is what the fundamental theorem on homomorphisms says.
Therefore "there aren't that many group homomorphism", and a normal subgroup it is a concrete and natural way to uniquely represent that homomorphism.
The best way to think about the, is to always think first: what is the homomorphism? And then work out everything else from there.
Cross files references to IDs: yes. But no check by default for duplicates when doing automatic ID from title. Just automatically disambiguates with
-1, -2 suffixes, and links take the last one available.Source page splitting: splits at h2 by default. If configurable, likely always af fixed level?
Has some nice image generation from inline code from standard R plotting functions.
Hello world documented at: bookdown.org/yihui/bookdown/get-started.html
Hello world on Ubuntu 23.04 after installing R:The build CLI comes from: stackoverflow.com/questions/50888871/how-to-use-rscript-command-line-tool-to-build-a-book-in-bookdown
sudo R -e 'install.packages("bookdown")'
git clone https://github.com/rstudio/bookdown-demo
cd bookdown-demo
Rscript -e 'bookdown::render_book("index.Rmd")'
xdg-open _book/index.htmlThe installatoin
Rscript -e 'bookdown::render_book("index.Rmd")' takes several minutes, it compiles a bunch of stuff from source apparently. but it did work.Each Bitcoin halvening event prompts a few commemorative messages, much like a New Year's even event in the real world.
1st (2012):
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/in/0209.txt: nothing
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/in/0210.txt: nothing
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/out/0209.txt#L1111: nothing, not even any ASCII
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/in/0209.txt#L132a; void
2nd (2016):
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/in/0419.txt#L407: nothing
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/in/0420.txt#L1:
- block 420000: "Chandler Guo loves YangYang Jin". Presumably this dude: twitter.com/ChandlerGuo. Noted e.g. at: www.reddit.com/r/Bitcoin/comments/4s14po/the_first_14_block_is_a_profession_of_love/
- block 420001: "/BTCC/ Welcome to 12.5 BTC blocks! BTCC & Bitcoin Forever!".
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/out/0419.txt#L10011: a few
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/out/0420.txt#L1: a few
3rd (2020):
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/in/0629.txt#L407
- block 629999: contains the miner message for: This quotes the title of: www.nytimes.com/2020/04/09/business/economy/fed-economic-rescue-coronavirus.html is of course a nod to the Genesis block message. Noted by Forbes at: www.forbes.com/sites/colinharper/2020/05/11/bitcoins-halving-block-includes-a-message-to-remind-us-why-it-was-created/?sh=130f001f656a It was mined by the F2Pool Bitcoin mining pool. A few halving output messages can be seen in nearby regular transactions:
NYTimes 09/Apr/2020 With $2.3T Injection, Fed's Plan Far Exceeds 2008 Rescue
- block 629999: contains the miner message for:
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/in/0630.txt#L1: nothing
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/out/0629.txt#L1111: a few
- github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/out/0630.txt#L1: a dozen such as:
- tx 0df655b7e50dc9a53c343308d1ca148d0bead993821dfe56a035aecd0c88b2ad "Happy 2020 Halving! Thank you Satoshi."
- tx 6c6c22b8fe87f1420df6d991f7b571fdaa29f7a95adbfbcfcb0644f1c8f7d82b "We love you forever @millsfogle"
- tx 70a8639bc9b743c0610d1231103a2f8e99f4a25670946b91f16c55a5373b37d1 "Happy 3rd halving! Thanks, Satoshi and COVID-19 GO AWAY! Bulgaria #1!!!"
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