Miscellaneous information and links

1. About 17beta

The web site https://17beta.top/ came online 2018-12-03; the first page was the one about pharmacology. On 2019-08-15 we moved most pages to https://male-to-female.org/. We assign IRIs with care that they will not break and leave dangling links; see https://17beta.top/en/identifiers.

2. Technical

2.1. Units of measurement

Everybody should know the basic principles of the SI –known popularily as the metric system. It is useful to communicate physical quantities day to day, and absolutely necessary in scientific contexts. The SI is not just yet another set of units; instead, it is the rationally designed systems of units of humanity. In specific, it includes a coherent subset of units. Here coherent means that there are no arbitrary conversion factors. The numerical value equations have the same form as the corresponding physical equations. Even the non-coherent units are related to each other and the coherent subset by powers of 10 which makes it trivial to do conversions mentally by shifting the radix point.

British Imperial and US customary units are obsolete and inacceptable. They involve many base units for the same dimensions with arbitrary ratios; for example 1 mile is equal to 5280 foot; the number 5280 has no physical significance. Moreover, composition of the named units with algebra results in units that conflict with the named ones. E.g.: 1 horsepower is equal to 550 foot-pound-force per second. Once again, the number 550 has no physical significance. These arbitrary conversion factor add clutter to formulas, distract from the physical meaning (especially among laypeople) and have to be memorized without any benefit.

2.2. Electricity

We speak of electric charges, electric currents, and so on. What is electricity? In the times of Maxwell, it referred to what we now call electric charges. Now it is used as a prefix to describe concrete concepts, but there is no single concrete physical phenomenon called “electricity”. The flow of charge is electric current. The separation of charge in a capacitor is called its charge.

2.3. Mathematics

  • “Introduction to Mathematical Logic”, 5th edition by Bert Mendelson can be recommended by the author. It is suitable for mathematicians new to formal logic (incl. set theory) and very motivated laypeople.
  • “Foundations of Analysis”, 3rd edition by Edmund Landau constructs the real numbers from the natural numbers (which is a part of the foundation of mathematics often handwaved by analysis books). It is a remarkable book for being very basic and having no formal prerequisites and at the same time very dense and impossible to understand intuitively without mathematical rigor.
  • “A course in number theory and cryptography”, 2th edition by Neal Koblitz: Exactly what it says on the title. It focuses on public key cryptography and includes a chapter on elliptic curves.
  • Metamath is a very simple proof assistant. It includes proofs with absolute rigor of a non-trivial part of mathematics. Most proofs are manually-generated and suitable for human reading.
  • HOL4 is a fully-fledgled proof assistant based on higher order logic, on which significant theories have been mechanized. It is highly extensible and suitable for use with automated theorem provers.
  • “Thousands of problems for theorem provers” (TPTP) is a collection of problems for automated theorem provers in a standard format. Associated with TPTP are regular competitions of automated theorem provers, under the name of CASC.
  • “The international SAT Competitions web page” contains links to the yearly competitions of boolean satisfiability solvers, which is a specific and solvable case of automated theorem proving.
  • “The Quantified Boolean Formulas Satisfiability Library”: Similar to the previous, but about solvers of quantified boolean formulas.
  • “E”: An automated theorem prover. As of 2019, it is overall the best free software prover for first order logic.
  • A home page for New Foundations set theory.
  • amasci.com: Information about overlooked and commonly misexplained physical phenomenon.

2.4. Other

3. Wisdom

“Poor are those people that only have money.” —Spanish-language proverb.

The Stoic Maxim: “I shall have the strength to change the things I can change, the serenity to accept the things I can not change and the wisdom to tell them apart”. This is a paraphrasis of a work by Reinhold Niebuhr.

There once was a factory of shoes that wanted to expand their market. They sent a shoe seller to an undeveloped country in Africa. The seller immediately returned back and reported total failure; nobody here wears shoes”. The company manager fired him, and sent his best shoe seller who did not disappoint. He reported back in a telegram “Excellent news! Nobody here wears shoes yet. I will be selling these in a heartbeat. Ship more crates of shoes!”.

4. Entertainment

4.1. Works of fiction

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