Vienna Standard Mean Ocean Water
Vienna Standard Mean Ocean Water, is an isotopic water standard defined in 1968 by the International Atomic Energy Agency. Despite the somewhat misleading phrase “ocean water”, VSMOW refers to pure water H2O and does not include any salt or other substances in seawater. VSMOW serves as a reference standard for comparing hydrogen and oxygen isotope ratios, mostly in water samples. Very pure, distilled VSMOW water is also used for making high accuracy measurement of water’s physical properties and for defining laboratory standards since it is considered to be representative of “average ocean water”, in effect representing the water content of Earth.
Previously average ocean water and melted snow were used as reference points. These were further refined in the 1960s by the standardized definition of Standard Mean Ocean Water (SMOW). The U.S. National Bureau of Standards (now the NIST) created physical water standards for global use. However, the physical integrity of the U.S. standards soon came into question.
Vienna Standard Mean Ocean Water – Wikipedia, the free encyclopedia
Chronomancy
Chronomancy stems from the word chronos (meaning time), and it is generally a fictional and sensational school of magic. Although the school is based on quantum physics and certain scientific theories, there is no concrete evidence of the perfected use of time manipulation.
Saw this across my feeds. Spent too long searching Wikipedia for it until I decided to look at the history page for Chronomancy.
Solar water disinfection
Solar water disinfection, also known as SODIS[1], is a method of disinfecting water using only sunlight and plastic PET bottles. SODIS is a cheap and effective method for decentralized water treatment, usually applied at the household level and is recommended by the World Health Organization as a viable method for household water treatment and safe storage [2]. SODIS is already applied in numerous developing countries.
Wow.
Canadian Cross Compile
A cross compiler is a compiler capable of creating executable code for a platform other than the one on which the compiler is run. Cross compiler tools are generally found in use to generate compiles for embedded system or multiple platforms. It is a tool that one must use for a platform where it is inconvenient or impossible to compile on that platform, like microcontrollers that run with a minimal amount of memory for their own purpose.
The Canadian Cross is a technique for building cross compilers for other machines. Given three machines A, B, and C, one uses machine A to build a cross compiler that runs on machine B to create executables for machine C. When using the Canadian Cross with GCC, there may be four compilers involved:
- The proprietary native Compiler for machine A (1) is used to build the gcc native compiler for machine A (2)
- The gcc native compiler for machine A (2) is used to build the gcc cross compiler from machine A to machine B (3)
- The gcc cross compiler from machine A to machine B (3) is used to build the gcc cross compiler from machine B to machine C (4)
The end-result cross compiler (4) will not be able to run on your build machine A; instead you would use it on machine B to compile an application into executable code that would then be copied to machine C and executed on machine C.
The term Canadian Cross came about because at the time that these issues were all being hashed out, Canada had three national political parties.
ISO Metric Screw Thread
The ISO metric screw threads are the world-wide most commonly used type of general-purpose screw thread. They were one of the first international standards agreed when the International Organization for Standardization was set up in 1947.
The design principles of ISO general-purpose metric screw threads (“M” series threads) are defined in international standard ISO 68-1. Each thread is characterized by its major diameter D and its pitch P. ISO metric threads consist of a symmetric V-shaped thread. In the plane of the thread axis, the flanks of the V have an angle of 60° to each other. The outermost 1/8 and the innermost 1/4 of the height H of the V-shape are cut off from the profile.
ISO Metric Screw Thread – Wikipedia
Pig Latin implementation in Lisp
Pulled from a Slashdot thread about engineers learning foreign languages:
(define (pigl wd)
(if (vowel? (first wd))
(word wd 'ay)
(pigl (word (bf wd) (first wd)))))
(define (vowel? letter)
(member? letter '(a e i o u)))
Doesn’t actually work, but still amusing nonetheless.