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Denotational semantics

In computer science, denotational semantics (initially known as mathematical semantics or Scott–Strachey semantics) is an approach of formalizing the meanings of programming languages by constructing mathematical objects (called denotations) that describe the meanings of expressions from the languages. Other approaches providing formal semantics of programming languages include axiomatic semantics and operational semantics.

Broadly speaking, denotational semantics is concerned with finding mathematical objects called domains that represent what programs do. For example, programs (or program phrases) might be represented by partial functions or by games between the environment and the system.

An important tenet of denotational semantics is that semantics should be compositional: the denotation of a program phrase should be built out of the denotations of its subphrases.

Historical development
Denotational semantics originated in the work of Christopher Strachey and Dana Scott published in the early 1970s. As originally developed by Strachey and Scott, denotational semantics provided the meaning of a computer program as a function that mapped input into output. To give meanings to recursively defined programs, Scott proposed working with continuous functions between domains, specifically complete partial orders. As described below, work has continued in investigating appropriate denotational semantics for aspects of programming languages such as sequentiality, concurrency, non-determinism and local state.

Denotational semantics has been developed for modern programming languages that use capabilities like concurrency and exceptions, e.g., Concurrent ML, CSP, and Haskell. The semantics of these languages is compositional in that the meaning of a phrase depends on the meanings of its subphrases. For example, the meaning of the applicative expression f(E1,E2) is defined in terms of semantics of its subphrases f, E1 and E2. In a modern programming language, E1 and E2 can be evaluated concurrently and the execution of one of them might affect the other by interacting through shared objects causing their meanings to be defined in terms of each other. Also, E1 or E2 might throw an exception which could terminate the execution of the other one. The sections below describe special cases of the semantics of these modern programming languages.

Meanings of recursive programs
Denotational semantics is ascribed to a program phrase as a function from an environment (holding current values of its free variables) to its denotation. For example, the phrase n*m produces a denotation when provided with an environment that has binding for its two free variables: n and m. If in the environment n has the value 3 and m has the value 5, then the denotation is 15.

A function can be represented as a set of ordered pairs of argument and corresponding result values. For example, the set {(0,1), (4,3)} denotes a function with result 1 for argument 0, result 3 for the argument 4, and undefined otherwise.

Consider for example the factorial function, which might be defined recursively as:

To provide a meaning for this recursive definition, the denotation is built up as the limit of approximations, where each approximation limits the number of calls to factorial. At the beginning, we start with no calls - hence nothing is defined. In the next approximation, we can add the ordered pair (0,1), because this doesn't require calling factorial again. Similarly we can add (1,1), (2,2), etc., adding one pair each successive approximation because computing factorial(n) requires n+1 calls. In the limit we get a total function from $$\mathbb{N}$$ to $$\mathbb{N}$$ defined everywhere in its domain.

Formally we model each approximation as a partial function $$\N \rightharpoonup \N$$. Our approximation is then repeatedly applying a function implementing "make a more defined partial factorial function", i.e. $$F : (\N \rightharpoonup \N) \to (\N \rightharpoonup \N) $$, starting with the empty function (empty set). F could be defined in code as follows (using  for  $$\N \rightharpoonup \N$$):

Then we can introduce the notation Fn to indicate F applied n times.
 * F0({}) is the totally undefined partial function, represented as the set {};
 * F1({}) is the partial function represented as the set {(0,1)}: it is defined at 0, to be 1, and undefined elsewhere;
 * F5({}) is the partial function represented as the set {(0,1), (1,1), (2,2), (3,6), (4,24)}: it is defined for arguments 0,1,2,3,4.

This iterative process builds a sequence of partial functions from $$\mathbb{N}$$ to $$\mathbb{N}$$. Partial functions form a chain-complete partial order using ⊆ as the ordering. Furthermore, this iterative process of better approximations of the factorial function forms an expansive (also called progressive) mapping because each $$F^i\le F^{i+1}$$ using ⊆ as the ordering. So by a fixed-point theorem (specifically Bourbaki–Witt theorem), there exists a fixed point for this iterative process.

In this case, the fixed point is the least upper bound of this chain, which is the full factorial function, which can be expressed as the union
 * $$\bigcup_{i \in \mathbb N} F^i(\{\}). $$

The fixed point we found is the least fixed point of F, because our iteration started with the smallest element in the domain (the empty set). To prove this we need a more complex fixed point theorem such as the Knaster–Tarski theorem.

Denotational semantics of non-deterministic programs
The concept of power domains has been developed to give a denotational semantics to non-deterministic sequential programs. Writing P for a power-domain constructor, the domain P(D) is the domain of non-deterministic computations of type denoted by D.

There are difficulties with fairness and unboundedness in domain-theoretic models of non-determinism.

Denotational semantics of concurrency
Many researchers have argued that the domain-theoretic models given above do not suffice for the more general case of concurrent computation. For this reason various new models have been introduced. In the early 1980s, people began using the style of denotational semantics to give semantics for concurrent languages. Examples include Will Clinger's work with the actor model; Glynn Winskel's work with event structures and Petri nets; and the work by Francez, Hoare, Lehmann, and de Roever (1979) on trace semantics for CSP. All these lines of inquiry remain under investigation (see e.g. the various denotational models for CSP ).

Recently, Winskel and others have proposed the category of profunctors as a domain theory for concurrency.

Denotational semantics of state
State (such as a heap) and simple imperative features can be straightforwardly modeled in the denotational semantics described above. The key idea is to consider a command as a partial function on some domain of states. The meaning of "x:=3" is then the function that takes a state to the state with 3 assigned to x. The sequencing operator ";" is denoted by composition of functions. Fixed-point constructions are then used to give a semantics to looping constructs, such as "while".

Things become more difficult in modelling programs with local variables. One approach is to no longer work with domains, but instead to interpret types as functors from some category of worlds to a category of domains. Programs are then denoted by natural continuous functions between these functors.

Denotations of data types
Many programming languages allow users to define recursive data types. For example, the type of lists of numbers can be specified by This section deals only with functional data structures that cannot change. Conventional imperative programming languages would typically allow the elements of such a recursive list to be changed.

For another example: the type of denotations of the untyped lambda calculus is The problem of solving domain equations is concerned with finding domains that model these kinds of datatypes. One approach, roughly speaking, is to consider the collection of all domains as a domain itself, and then solve the recursive definition there.

Polymorphic data types are data types that are defined with a parameter. For example, the type of α lists is defined by Lists of natural numbers, then, are of type nat list, while lists of strings are of string list.

Some researchers have developed domain theoretic models of polymorphism. Other researchers have also modeled parametric polymorphism within constructive set theories.

A recent research area has involved denotational semantics for object and class based programming languages.

Denotational semantics for programs of restricted complexity
Following the development of programming languages based on linear logic, denotational semantics have been given to languages for linear usage (see e.g. proof nets, coherence spaces) and also polynomial time complexity.

Denotational semantics of sequentiality
The problem of full abstraction for the sequential programming language PCF was, for a long time, a big open question in denotational semantics. The difficulty with PCF is that it is a very sequential language. For example, there is no way to define the parallel-or function in PCF. It is for this reason that the approach using domains, as introduced above, yields a denotational semantics that is not fully abstract.

This open question was mostly resolved in the 1990s with the development of game semantics and also with techniques involving logical relations. For more details, see the page on PCF.

Denotational semantics as source-to-source translation
It is often useful to translate one programming language into another. For example, a concurrent programming language might be translated into a process calculus; a high-level programming language might be translated into byte-code. (Indeed, conventional denotational semantics can be seen as the interpretation of programming languages into the internal language of the category of domains.)

In this context, notions from denotational semantics, such as full abstraction, help to satisfy security concerns.

Abstraction
It is often considered important to connect denotational semantics with operational semantics. This is especially important when the denotational semantics is rather mathematical and abstract, and the operational semantics is more concrete or closer to the computational intuitions. The following properties of a denotational semantics are often of interest.
 * 1) Syntax independence: The denotations of programs should not involve the syntax of the source language.
 * 2) Adequacy (or soundness): All observably distinct programs have distinct denotations;
 * 3) Full abstraction: All observationally equivalent programs have equal denotations.

For semantics in the traditional style, adequacy and full abstraction may be understood roughly as the requirement that "operational equivalence coincides with denotational equality". For denotational semantics in more intensional models, such as the actor model and process calculi, there are different notions of equivalence within each model, and so the concepts of adequacy and of full abstraction are a matter of debate, and harder to pin down. Also the mathematical structure of operational semantics and denotational semantics can become very close.

Additional desirable properties we may wish to hold between operational and denotational semantics are:
 * 1) Constructivism: Constructivism is concerned with whether domain elements can be shown to exist by constructive methods.
 * 2) Independence of denotational and operational semantics: The denotational semantics should be formalized using mathematical structures that are independent of the operational semantics of a programming language; However, the underlying concepts can be closely related. See the section on Compositionality below.
 * 3) Full completeness or definability: Every morphism of the semantic model should be the denotation of a program.

Compositionality
An important aspect of denotational semantics of programming languages is compositionality, by which the denotation of a program is constructed from denotations of its parts. For example, consider the expression "7 + 4". Compositionality in this case is to provide a meaning for "7 + 4" in terms of the meanings of "7", "4" and "+".

A basic denotational semantics in domain theory is compositional because it is given as follows. We start by considering program fragments, i.e. programs with free variables. A typing context assigns a type to each free variable. For instance, in the expression (x + y) might be considered in a typing context (x:nat,y:nat). We now give a denotational semantics to program fragments, using the following scheme.
 * 1) We begin by describing the meaning of the types of our language: the meaning of each type must be a domain. We write 〚τ〛 for the domain denoting the type τ. For instance, the meaning of type nat should be the domain of natural numbers: 〚nat〛= $$\mathbb{N}$$⊥.
 * 2) From the meaning of types we derive a meaning for typing contexts. We set 〚 x1:τ1,..., xn:τn〛 = 〚 τ1〛× ... ×〚τn〛. For instance, 〚x:nat,y:nat〛= $$\mathbb{N}$$⊥×$$\mathbb{N}$$⊥. As a special case, the meaning of the empty typing context, with no variables, is the domain with one element, denoted 1.
 * 3) Finally, we must give a meaning to each program-fragment-in-typing-context. Suppose that P is a program fragment of type σ, in typing context Γ, often written Γ⊢P:σ. Then the meaning of this program-in-typing-context must be a continuous function 〚Γ⊢P:σ〛:〚Γ〛→〚σ〛. For instance, 〚⊢7:nat〛:1→$$\mathbb{N}$$⊥ is the constantly "7" function, while 〚x:nat,y:nat⊢x+y:nat〛:$$\mathbb{N}$$⊥×$$\mathbb{N}$$⊥→$$\mathbb{N}$$⊥ is the function that adds two numbers.

Now, the meaning of the compound expression (7+4) is determined by composing the three functions 〚⊢7:nat〛:1→$$\mathbb{N}$$⊥, 〚⊢4:nat〛:1→$$\mathbb{N}$$⊥, and 〚x:nat,y:nat⊢x+y:nat〛:$$\mathbb{N}$$⊥×$$\mathbb{N}$$⊥→$$\mathbb{N}$$⊥.

In fact, this is a general scheme for compositional denotational semantics. There is nothing specific about domains and continuous functions here. One can work with a different category instead. For example, in game semantics, the category of games has games as objects and strategies as morphisms: we can interpret types as games, and programs as strategies. For a simple language without general recursion, we can make do with the category of sets and functions. For a language with side-effects, we can work in the Kleisli category for a monad. For a language with state, we can work in a functor category. Milner has advocated modelling location and interaction by working in a category with interfaces as objects and bigraphs as morphisms.

Semantics versus implementation
According to Dana Scott (1980):
 * It is not necessary for the semantics to determine an implementation, but it should provide criteria for showing that an implementation is correct.

According to Clinger (1981):
 * Usually, however, the formal semantics of a conventional sequential programming language may itself be interpreted to provide an (inefficient) implementation of the language. A formal semantics need not always provide such an implementation, though, and to believe that semantics must provide an implementation leads to confusion about the formal semantics of concurrent languages.  Such confusion is painfully evident when the presence of unbounded nondeterminism in a programming language's semantics is said to imply that the programming language cannot be implemented.

Connections to other areas of computer science
Some work in denotational semantics has interpreted types as domains in the sense of domain theory, which can be seen as a branch of model theory, leading to connections with type theory and category theory. Within computer science, there are connections with abstract interpretation, program verification, and model checking.

title: Denotational semantics


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Warp drive

A warp drive or a drive enabling space warp is a fictional superluminal (faster than the speed of light) spacecraft propulsion system in many science fiction works, most notably Star Trek, and a subject of ongoing physics research. The general concept of "warp drive" was introduced by John W. Campbell in his 1957 novel Islands of Space and was popularized by the Star Trek series. Its closest real-life equivalent is the Alcubierre drive, a theoretical solution of the field equations of general relativity.

History and characteristics
Warp drive, or a drive enabling space warp, is one of several ways of travelling through space found in science fiction. It has been often discussed as being conceptually similar to hyperspace. A warp drive is a device that distorts the shape of the space-time continuum. A spacecraft equipped with a warp drive may travel at speeds greater than that of light by many orders of magnitude. In contrast to some other fictitious faster-than-light technologies such as a jump drive, the warp drive does not permit instantaneous travel and transfers between two points, but rather involves a measurable passage of time which is pertinent to the concept. In contrast to hyperspace, spacecraft at warp velocity would continue to interact with objects in "normal space".

The general concept of warp drive was introduced by John W. Campbell in his 1957 novel Islands of Space.  Brave New Words gave the earliest example of the term "space-warp drive" as Fredric Brown's Gateway to Darkness (1949), and also cited an unnamed story from Cosmic Stories (May 1941) as using the word "warp" in the context of space travel, although the usage of this term as a "bend or curvature" in space which facilitates travel can be traced to several works at as far back as the mid-1930s, for example Jack Williamson's The Cometeers (1936).

Einstein's space warp and real-world physics
Einstein's theory of special relativity states that speed of light travel is impossible for material objects that, unlike photons, have a non-zero rest mass. The problem of a material object exceeding light speed is that an infinite amount of kinetic energy would be required to travel at exactly the speed of light. Warp drives are one of the science-fiction tropes that serve to circumvent this limitation in fiction to facilitate stories set at galactic scales. However, the concept of space warp has been criticized as "illogical", and has been connected to several other rubber science ideas that do not fit into our current understanding of physics, such as antigravity or negative mass.

Some argue that these effects mean that although it's not possible to travel faster than the speed of light, both space and time "warp" to allow travelling the distance of one light year, in less than a year. Although it is not possible to travel faster than the speed of light, the effective speed is faster than light. This warping of space and time is precisely mathematically specified by the Lorentz factor, which depends on velocity. Although only theoretical when published over 100 years ago, the effect has since been measured and confirmed many times. In the limit, at light speed time stops completely and it is possible to travel infinite distances across space with no passage of time.

Although the concept of warp drive has originated in fiction, it has received some scientific consideration, most notably related to the 1990s concept of the Alcubierre drive. Alcubierre stated in an email to William Shatner that his theory was directly inspired by the term used in the TV series Star Trek and cites the "'warp drive' of science fiction" in his 1994 article.

In 2021, DARPA-funded researcher Harold White, of the Limitless Space Institute, claimed that he had succeeded in creating a real warp bubble, saying "our detailed numerical analysis of our custom Casimir cavities helped us identify a real and manufacturable nano/microstructure that is predicted to generate a negative vacuum energy density such that it would manifest a real nanoscale warp bubble, not an analog, but the real thing."

Star Trek
Warp drive is one of the fundamental features of the Star Trek franchise and one of the best-known examples of space warp (warp drive) in fiction. In the first pilot episode of Star Trek: The Original Series, "The Cage", it is referred to as a "hyperdrive", with Captain Pike stating the speed to reach planet TalosIV as "time warp, factor 7". The warp drive in Star Trek is one of the most detailed fictional technologies. Compared to the hyperspace drives of other fictional universes, it differs in that a spaceship does not leave the normal space-time continuum and instead the space-time itself is distorted, as is made possible in the general theory of relativity.

The basic functional principle of the warp drive in Star Trek is the same for all spaceships. A strong energy source, usually a so-called  warp core  or sometimes called intermix chamber, generates a high-energy plasma. This plasma is transported to the so-called warp field generators via lines that are reminiscent of pipes. These generators are basically coils in warp nacelles protruding from the spaceship. These generate a subspace field, the so-called warp field or a warp bubble, which distort space-time and propels the bubble and spaceship in the bubble forward.

The warp core can be designed in various forms. Humans and most of the other fictional races use a moderated reaction of antideuterium and deuterium. The energy produced passes through a matrix, which is made of a fictional chemical element, called dilithium. However, other species are shown to use different methods for faster-than-light propulsion. The Romulans, for example, use artificial micro-black holes called quantum singularities.

The speeds are given in warp factors and follow a Geometric progression. The first scale developed by Franz Joseph was simply a cubic progression with no limit. This leads to the use of ever growing warp factors in the Original Series and the Animated Series. For example, warp 14.1 in the TOS-episode "That Which Survives" or warp 36 in the TAS-episode "The Counter-Clock Incident". In order to focus more on the story and away from the technobabble, Gene Roddenberry commissioned Michael Okuda to invent a revised warp scale. Warp 10 should be the absolute limit and stand for infinite speed. In homage to Gene Roddenberry, this limit was also called "Eugene's Limit". Okuda explains this in an author's comment in his technical manual for the USS Enterprise-D. Between Warp 1 (the speed of light) and Warp 9, the increase was still roughly geometric, but the exponent was adjusted so that the speeds were higher compared to the old scale. For instance, Warp 9 is more than 1500 times faster than Warp 1 in comparison to the 729 times (nine to the power of 3) calculated using the original cubic formula. In the same author's comment, Okuda explains that the motivation was to fulfill fan expectations that the new Enterprise is much faster than the original, but without changing the warp factor numbers. Between Warp 9 and Warp 10, the new scale grows exponentially. Only in a single episode of Star Trek Voyager there was a specific numerical speed value given for a warp factor. In the episode "The 37's", Tom Paris tells Amelia Earhart that Warp 9.9 is about 4 billion miles per second (using customary units for the character's benefit). That is more than 14 times the value of Warp 9 and equal to around 21,400 times speed of light. However, this statement contradicts the technical manuals and encyclopedias written by Rick Sternbach and Michael Okuda, where a speed of 3053 times the speed of light was established for a warp factor of 9.9 and a speed of 7912 times the speed of light for a warp factor of 9.99. Both numerical values are well below the value given by Tom Paris.

In the episode "Vis à Vis", a coaxial warp drive is mentioned. The working principle is explained in more detail in the Star Trek Encyclopedia. This variant of a warp drive uses spatial folding instead of a warp field and allows an instant movement with nearly infinite velocity.

Star Trek has also introduced a so-called Transwarp concept, but without a fixed definition. It is effectively a catch-all phrase for any and all technologies and natural phenomena that enable speeds above Warp 9.99.

Rick Sternbach described the basic idea in the Technical Manual: "'Finally, we had to provide some loophole for various powerful aliens like Q, who have a knack for tossing the ship million of light years in the time of a commercial break. [...] This lets Q and his friends have fun in the 9.9999+ range, but also lets our ship travel slowly enough to keep the galaxy a big place, and meets the other criteria.'"

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Warp drive


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James Dewar

Sir James Dewar (20 September 1842 – 27 March 1923) was a British chemist and physicist. He is best known for his invention of the vacuum flask, which he used in conjunction with research into the liquefaction of gases. He also studied atomic and molecular spectroscopy, working in these fields for more than 25 years.

Early life
James Dewar was born in Kincardine, Perthshire (now in Fife) in 1842, the youngest of six boys of Ann Dewar and Thomas Dewar, a vintner. He was educated at Kincardine Parish School and then Dollar Academy. His parents died when he was 15. He attended the University of Edinburgh where he studied chemistry under Lyon Playfair (later Baron Playfair), becoming Playfair's personal assistant. Dewar also studied under August Kekulé at Ghent.

Career
In 1875, Dewar was elected Jacksonian professor of natural experimental philosophy at the University of Cambridge, becoming a member of Peterhouse. He became a member of the Royal Institution and later, in 1877, replaced Dr John Hall Gladstone in the role of Fullerian Professor of Chemistry. Dewar was also the President of the Chemical Society in 1897 and the British Association for the Advancement of Science in 1902, as well as serving on the Royal Commission established to examine London's water supply from 1893 to 1894 and the Committee on Explosives. While serving on the Committee on Explosives, he and Frederick Augustus Abel developed cordite, a smokeless gunpowder alternative.

In 1867 Dewar described several chemical formulas for benzene, which were published in 1869. One of the formulae, which does not represent benzene correctly and was not advocated by Dewar, is sometimes still called Dewar benzene. In 1869 he was elected a Fellow of the Royal Society of Edinburgh, his proposer being his former mentor, Lyon Playfair. His scientific work covers a wide field – his earlier papers cover topics including organic chemistry, hydrogen and its physical constants, high-temperature research, the temperature of the Sun and of the electric spark, spectrophotometry, and the chemistry of the electric arc.

With Professor J. G. McKendrick, of the University of Glasgow, he investigated the physiological action of light and examined the changes that take place in the electrical condition of the retina under its influence. With Professor G. D. Liveing, one of his colleagues at the University of Cambridge, he began in 1878 a long series of spectroscopic observations, the later of which were devoted to the spectroscopic examination of various gaseous elements separated from atmospheric air by the aid of low temperatures. He was joined by Professor J. A. Fleming, of University College London, in the investigation of the electrical behaviour of substances cooled to very low temperatures.

His name is most widely known in connection with his work on the liquefaction of the so-called permanent gases and his researches at temperatures approaching absolute zero. His interest in this branch of physics and chemistry dates back at least as far as 1874, when he discussed the "Latent Heat of Liquid Gases" before the British Association. In 1878, he devoted a Friday evening lecture at the Royal Institution to the then-recent work of Louis Paul Cailletet and Raoul Pictet, and exhibited for the first time in Great Britain the working of the Cailletet apparatus. Six years later, again at the Royal Institution, he described the researches of Zygmunt Florenty Wróblewski and Karol Olszewski, and illustrated for the first time in public the liquefaction of oxygen and air. Soon afterward, he built a machine from which the liquefied gas could be drawn off through a valve for use as a cooling agent, before using the liquid oxygen in research work related to meteorites; about the same time, he also obtained oxygen in the solid state. By 1891, he had designed and built, at the Royal Institution, machinery which yielded liquid oxygen in industrial quantities, and towards the end of that year, he showed that both liquid oxygen and liquid ozone are strongly attracted by a magnet. About 1892, the idea occurred to him of using vacuum-jacketed vessels for the storage of liquid gases – the Dewar flask (otherwise known as a Thermos or vacuum flask) – the invention for which he became most famous. The vacuum flask was so efficient at keeping heat out, it was found possible to preserve the liquids for comparatively long periods, making an examination of their optical properties possible. Dewar did not profit from the widespread adoption of his vacuum flask – he lost a court case against Thermos concerning the patent for his invention. While Dewar was recognised as the inventor, because he did not patent his invention, there was no way to prevent Thermos from using his design.

He next experimented with a high-pressure hydrogen jet by which low temperatures were realised through the Joule–Thomson effect, and the successful results he obtained led him to build at the Royal Institution a large regenerative cooling refrigerating machine. Using this machine in 1898, liquid hydrogen was collected for the first time, solid hydrogen following in 1899. He tried to liquefy the last remaining gas, helium, which condenses into a liquid at −268.9 °C, but owing to a number of factors, including a short supply of helium, Dewar was preceded by Heike Kamerlingh Onnes as the first person to produce liquid helium, in 1908. Onnes would later be awarded the Nobel Prize in Physics for his research into the properties of matter at low temperatures – Dewar was nominated several times, but never succeeded in winning the Nobel Prize.

In 1905, he began to investigate the gas-absorbing powers of charcoal when cooled to low temperatures and applied his research to the creation of high vacuum, which was used for further experiments in atomic physics. Dewar continued his research work into the properties of elements at low temperatures, specifically low-temperature calorimetry, until the outbreak of World War I. The Royal Institution laboratories lost a number of staff to the war effort, both in fighting and scientific roles, and after the war, Dewar had little interest in restarting the serious research work that went on before the war. Shortages of scholars necessarily compounded the problems. His research during and after the war mainly involved investigating surface tension in soap bubbles, rather than further work into the properties of matter at low temperatures.

Family
He married Helen Rose Banks in 1871. They had no children. Helen was sister-in-law to both Charles Dickson, Lord Dickson and James Douglas Hamilton Dickson.

Dewar's nephew, Dr Thomas William Dewar FRSE, was an amateur artist, who painted a portrait of Sir James Dewar. He is presumably also the same Thomas William Dewar who was mentioned as executor in James Dewar's will, ultimately replaced "unopposed" by Dewar's wife.

Royal Institution Christmas Lectures
Dewar was invited to deliver several Royal Institution Christmas Lectures:

 * A Soap Bubble (1878)
 * Atoms (1880)
 * Alchemy in Relation to Modern Science (1883)
 * The Story of a Meteorite (1885)
 * The Chemistry of Light and Photography (1886)
 * Clouds and Cloudland (1888)
 * Frost and Fire (1890)
 * Air: Gaseous and Liquid (1893)
 * Christmas Lecture Epilogues (1912)

Honours and awards
Whilst Dewar was never recognised by the Swedish Academy, he was recognised by many other institutions both before and after his death, in Britain and overseas. The Royal Society elected him a Fellow of the Royal Society in June 1877 and bestowed their Rumford (1894), Davy (1909), and Copley Medal (1916) medals upon him for his work, as well as inviting him to deliver their Bakerian Lecture in 1901. In 1899, he became the first recipient of the Hodgkins gold medal of the Smithsonian Institution, Washington, DC, for his contributions to knowledge of the nature and properties of atmospheric air. That same year, he was elected to the American Philosophical Society. He was elected to the United States National Academy of Sciences in 1907.

He was President of the Society of Chemical Industry from 1887-88.

In 1904, he was the first British subject to receive the Lavoisier Medal of the French Academy of Sciences, and in 1906, he was the first to be awarded the Matteucci Medal of the Italian Society of Sciences. He was knighted in 1904 and awarded the Gunning Victoria Jubilee Prize for 1900–1904 by the Royal Society of Edinburgh, and in 1908, he was awarded the Albert Medal of The Society of Arts. A lunar crater was named in his honour.

A street within the Kings Buildings complex of the University of Edinburgh was named in memory of Dewar in the early 21st century.

Later life
Dewar died on 27 March 1923 aged 80 and was cremated at Golders Green Crematorium in London. An urn with his ashes still resides there.

Character

Dewar's irascibility was legendary. Rowlinson (2012) called him "ruthless", particularly with his colleague Siegfried Ruhemann.

Selected publications

 * , G. D. Living and J. Dewar, Cambridge University Press, 1915

 * Pippard, Brian. 1993. "Siegfried Ruhemann (1859-1943), F.R.S. 1914-1923." Notes and Records of the Royal Society of London 47 (2): 271–76.
 * Rowlinson, Sir J. S. 2012. Sir James Dewar, 1842–1923: A Ruthless Chemist. Ashgate Publishing, Ltd.

title: James Dewar


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Grand Prix

Grand Prix (, meaning Grand Prize; plural Grands Prix), is a name rooted in competitions (such as sport events), alluding to the winner receiving a prize, trophy or honor.

Grand Prix or grand prix may refer to:

Films

 * Grand Prix (1934 film), a British motorsports drama film
 * Grand Prix (1966 film), a U.S. drama film about Formula One motor racing
 * Grand Prix (2010 film), a South Korean horseracing drama film
 * Grand Prix (2022 film), a Czech film

Music

 * Grand Prix (album), by Teenage Fanclub
 * Grand Prix (band), English rock band
 * Grand Prix (song), by South Korean girl group Kep1er
 * European Grand Prix for Choral Singing, an annual choral competition between the winners of six European choral competitions
 * Eurovision Song Contest (originally named Grand Prix d'Eurovision de la Chanson)
 * Dansk Melodi Grand Prix, Danish selection for Eurovision Song Contest
 * Melodi Grand Prix, Norwegian selection for Eurovision Song Contest

Table or card games

 * Grand Prix (Magic: The Gathering), magic tournaments

Television

 * Grand Prix, a character from Adventure Time episode "Daddy-Daughter Card Wars"
 * "Grand Prix" (CSI: Miami), seventh episode from second season of CSI: Miami
 * Grand Prix (TV programme), BBC Television's TV coverage of Formula One motor racing
 * El Grand Prix del verano, Spanish television game show

Video games

 * Grand Prix (video game) by Activision
 * F-1 Sensation, the Japanese/European version of the cancelled NES game Grand Prix
 * Formula One Grand Prix (video game)
 * Grand Prix Challenge, by Atari
 * Grand Prix Circuit (video game), by Accolade
 * Grand Prix Legends (1967 season)
 * Mario Kart Arcade GP, an arcade game in the Mario Kart series.

Awards

 * Grand Prix de Rome, scholarship awarded in France from 1663 to 1968
 * Grand Prix (Belgian Film Critics Association)
 * Grand Prix at Brussels International Film Festival (BRIFF)
 * Grand Prix (Cannes Film Festival)
 * Grand Prix at International Film Festival Bratislava
 * Grand Prix de la ville d'Angoulême, a comics award
 * Grand Prix de Littérature Policière, annual literary award for French and international crime fiction
 * Grand prix Gobert is one of the prizes of the French Academy. It has been awarded every year in the field of history since 1834.
 * Les Grands Prix, annual awards from the foundations of the Institut de France

Athletics

 * IAAF Grand Prix Final, an athletics competitions replaced by the IAAF World Athletics Final
 * IAAF Super Grand Prix, a series of athletics meetings held until 2009

Chess

 * FIDE Grand Prix
 * Grand Prix Attack, a chess opening
 * USCF Grand Prix

Combat sports

 * D-Oh Grand Prix, annual professional wrestling tournament held by DDT Pro-Wrestling
 * Dream Grand Prix, various mixed martial arts Dream Grand Prix tournaments
 * International Fight League (IFL) Grand Prix, various mixed martial arts IFL Grand Prix tournaments
 * International Wrestling Grand Prix, the governing body for the wrestling promotion New Japan Pro-Wrestling
 * K-1 World Grand Prix, K-1's annual kickboxing World Grand Prix tournaments
 * Pride Grand Prix, held by Pride Fighting Championships
 * Strikeforce Grand Prix, a competition run by Strikeforce

Cycling

 * Grand Prix Chantal Biya, a road bicycle racing event
 * Grand Prix Velo Alanya (disambiguation)
 * U.S. Gran Prix of Cyclocross, a cyclo-cross bicycle racing series

Equestrianism

 * Grand Prix, now Prix Gladiateur, a horse race in France since 1862
 * Grand Prix Dressage
 * Grand Prix show jumping
 * Nakayama Grand Prix, original name of the Arima Kinen horse race in Japan

Motorsport

 * A1 Grand Prix
 * Aero GP, flying competition
 * D1 Grand Prix
 * Grand Prix Masters
 * Grand Prix motor racing, major races since 1907, governed by Formula One (F1) since 1950
 * Macau Grand Prix (not F1)
 * New Zealand Grand Prix (not F1)
 * Grand Prix motorcycle Road Racing, known commonly as MotoGP after its premier class
 * Purdue Grand Prix, a Go-Kart race held at Purdue University
 * Speedway Grand Prix (motorcycle speedway)
 * MXGP, main class in Motocross World Championship

Snooker

 * World Grand Prix (snooker)
 * Xi'an Grand Prix
 * Grand Prix (snooker), a former name of the World Open
 * Six-red World Grand Prix, a former name of the Six-red World Championship
 * Malta Grand Prix, a former professional snooker tournament
 * Norwich Union Grand Prix, a former professional snooker tournament

Tennis

 * Budapest Grand Prix
 * Grand Prix tennis circuit
 * Marrakech Grand Prix
 * Porsche Tennis Grand Prix

Other sports

 * World Grand Prix (darts)
 * FIVB World Grand Prix, for women's volleyball
 * Grand Prix de Futsal, international futsal competition
 * Grand Prix gliding
 * ISU Grand Prix of Figure Skating
 * Rhythmic Gymnastics Grand Prix Series
 * Sevens Grand Prix Series, European rugby tournaments
 * The Grand Prix, greyhound racing competition

Other uses

 * Pontiac Grand Prix, an American automobile formerly manufactured by General Motors

title: Grand Prix


text:
Canning Stock Route

The Canning Stock Route is a track that runs from Halls Creek in the Kimberley region of Western Australia to Wiluna in the mid-west region. With a total distance of around 1,850 km (1,150 mi) it is claimed to be the longest historic stock route in the world.

A 1928 Royal Commission into the price of beef in Western Australia led to the repair of the wells and the re-opening of the stock route. Around 20 droves took place between 1931 and 1959 when the final droving run was completed.

The Canning Stock Route is now a popular but challenging four-wheel drive trek typically taking 10 to 20 days to complete. A few adventurers have traversed the track on foot, by bicycle, motorcycle and in two-wheel drive vehicles.

There are two small settlements on the track where fuel and other supplies may be obtained; Kunawarritji, approximately 1000 km north of Wiluna, and Billiluna, 173 km south of Halls Creek.

In March 2020, the route was closed to tourists due to the COVID-19 pandemic. It was reopened on 14 June 2022.

History
In Western Australia at the beginning of the 20th century, east Kimberley cattlemen were looking for a way to traverse the western deserts of Australia with their cattle as a way to break a west Kimberley monopoly that controlled the supply of beef to Perth and the goldfields in the south of the state. East Kimberley cattle were infested with Boophilus ticks infected with a malaria-like parasitic disease called Babesiosis and were prohibited from being transported to southern markets by sea due to a fear that the ticks would survive the journey and spread. This gave west Kimberley cattlemen a monopoly on the beef trade and resulted in high prices.

With east Kimberley cattlemen keen to find a way to get their cattle to market, and the Government of Western Australia keen for competition to bring prices down, a 1905 proposal of a stock route through the desert was taken seriously. James Isdell, an east Kimberley pastoralist and member of the Western Australian Legislative Assembly, proposed the stock route arguing that ticks would not survive in the dry desert climate on the trip south.

Calvert and Carnegie expeditions
The route, which crossed the territories of nine different Aboriginal language groups, had been explored previously in 1896 by the Calvert Expedition led by Lawrence Wells and again later that year by the Carnegie Expedition led by David Carnegie. Two members of the Calvert Expedition perished of thirst and the Carnegie Expedition suffered considerable hardships with camels dying after eating poisonous grass and a member of the party accidentally shooting himself dead. Carnegie investigated the possibility of a stock route and concluded that the route was "too barren and destitute of vegetation" and was impractical.

Wells and Carnegie both mistreated Aboriginals they encountered on their expeditions, including by tying them up and forcing them to find water. Carnegie is also believed to have fed them salt, and he was later publicly criticised for this. Evidence supports that Alfred Canning had read both the Calvert and Carnegie expedition accounts to find out about the country (both described the terrain as "extremely difficult") and the use of Aboriginal people to find water, an example Canning followed during his own expedition.

Canning survey
After it was determined that ticks could not survive a desert crossing, the government endorsed James Isdell's scheme and funded a survey to find a stock route that would cross the Great Sandy Desert, the Little Sandy Desert and the Gibson Desert. Alfred Canning, a surveyor with the Western Australian Department of Lands and Surveys, was appointed to survey the stock route.

Canning's task was to find a route through 1850 kilometres of desert, from Wiluna in the mid west to the Kimberley in the north. He needed to find significant water sources – enough for up to 800 head of cattle, a day's walk apart – where wells could be dug, and enough good grazing land to sustain this number of cattle during the journey south.

In 1906, with a team of 23 camels, two horses, and eight men, Canning surveyed the route completing the difficult journey from Wiluna to Halls Creek in less than six months. On 1 November 1906, shortly after arriving in Halls Creek, Canning sent a telegram to Perth stating that the finished route would "be about the best watered stock route in [the] Colony". Canning was forced to delay his return journey because of an early wet season in the Kimberley that year. The survey party left Halls Creek in late January 1907 and arrived back in Wiluna in early July 1907. During the 14-month expedition, they had trekked about 4000 km, relying on Aboriginal guides to help them find water.

Canning had always planned to rely on Aboriginal guides to help him find water and had taken neck chains and handcuffs supplied to him by the Wiluna police to make sure local "guides" stayed as long as he needed them. In order to gain assistance in locating water along the route, Canning captured several Martu men, chained them by the neck and forced them to lead his party to native water sources (soaks). As many soaks were sacred, the Martu may have misdirected the explorers away from these, resulting in the eventual stock route winding more than would otherwise have been necessary.

Royal Commission into treatment of Aboriginal people
After the Canning survey party returned to Perth, Canning's use of Aboriginal guides came under scrutiny. The expedition's cook, Edward Blake, accused Canning of mistreating many of the Aboriginal people they met during the survey expedition. Blake objected to the use of chains and criticised the "party's 'immoral' pursuit of Aboriginal women, the theft and 'unfair' trade of Aboriginal property and the destruction of native waters". Blake was concerned that the planned wells would prevent Aboriginal people accessing water. Blake's complaints led to a Royal Commission into the treatment of natives by the Canning exploration party.

Blake was unable to prove many of his claims, but Canning did admit to the use of chains. Kimberley explorer and the first Premier of Western Australia, John Forrest, dismissed Canning's actions by claiming that all explorers behaved in this manner. Despite condemning the use of chains, the Royal Commission accepted the survey party's actions as "reasonable" and Canning and his men were exonerated of all charges, including "immorality with native women" and stealing property. The Royal Commission approved the immediate commencement of the stock route's construction. Canning was appointed to lead the construction party.

Construction
Canning left Perth in March 1908, along with 30 men, 70 camels, four wagons, 100 tonnes of food and equipment and 267 goats (for milk and meat), and travelled the route again to commence the construction of well heads and water troughs at the 54 water sources identified by his earlier expedition. He arrived back in Wiluna in April 1910 having completed the last of 48 wells and bringing the total cost of the route to £22000 (2010: A$2.6 million).

Thirty-seven of the wells were built on or near existing Aboriginal waters and were constructed in the European tradition, which made many of them inaccessible to Aboriginal people. Pulling the heavy buckets up from the bottom of the wells required the strength of three men or use of a camel. Consequentially, many Aboriginal people were injured or died while trying to access the water, either falling in and drowning or breaking bones on the windlass handle. In reprisal, buckets were cut off or timber set on fire, and by 1917 Aboriginal people had vandalised or dismantled approximately half of the wells in a bid to reclaim access to the water or to prevent drovers from using the wells. Canning's party had constructed the wells with the forced help of one of the Aboriginal peoples whose land the route traversed, the Martu.

Canning produced a detailed map of the stock route, Plan of Wiluna–Kimberley stock route exploration (showing positions of wells constructed 1908–9 and 10) on which he also recorded his observations of the land and water sources along the route. The map has become a symbol of Australia's pioneering history.

First droving runs
Commercial droving along the stock route began in 1910. The first few droves were of small groups of horses – the first started out with 42 horses of which only nine survived the journey.

The first mob of bullocks to attempt to use the stock route set out in January 1911; however the party of three drovers, George Shoesmith, James Thompson and an Aboriginal stockman who was known as "Chinaman", were killed by Aboriginals at Well 37. Thomas Cole discovered their bodies later in 1911 during his successful drove along the stock route. In September 1911, Sergeant R.H. Pilmer led a police "punitive expedition" to find the culprits and ensure the stock route remained open. The police made no arrests, but the expedition was considered a success after Pilmer acknowledged killing at least 10 Aboriginals.

On 7 September 1911 it was reported that the first mob of cattle to traverse the entire length of the stock route had successfully arrived in Wiluna. The cattle had apparently gained condition on the long drove.

The stock route was closed at some time prior to 1925. In 1925 the Billiluna Pastoral Company requested that it be reopened. The state government refused saying that it had fallen into disrepair from disuse as a result of stockmen being attacked by Aboriginals. The government claimed it would cost £5,625 and take six months to repair and refused to consider the expenditure at that time.

Despite police protection, drovers were afraid to use the track and it was rarely used for almost 20 years. Between 1911 and 1931, only eight mobs of cattle were driven along the Canning Stock Route.

Reopening of the stock route
A 1928 Royal Commission into the price of beef in Western Australia led to the re-opening of the stock route. In 1929, William Snell was commissioned to repair the wells and found that the only wells undamaged were the ones that Aboriginal people could use. Snell criticised the construction of Canning's wells because they were difficult for Aboriginal people to use safely, and he put the destruction of the wells down to the anger and frustration people felt at being unable to access traditional water sources. Snell personally committed to making the wells more accessible to Aboriginal people:"Natives cannot draw water from the Canning Stock Route wells. It takes three strong white men to land a bucket of water. It is beyond the natives power to land a bucket. They let go the handle [and] some times escape with their life but get an arm and head broken in the attempt to get away. To heal the wounds so severely inflicted and [as] a safeguard against the natives destroying the wells again I equipped the wells ... so that the native can draw water from the wells without destroying them.—William Snell"

Snell started work on the refurbishment of the wells, fitting some with ladders for easier access, but he abandoned the work after well 35. Reports vary that he either ran out of materials or the desert became too much for him.

In 1930, Alfred Canning (then aged 70) was commissioned to complete the work. While Snell had encountered no hostility, Canning had trouble with the Aboriginals from the start but successfully completed the commission in 1931.

With these improvements, the route was used on a more regular basis although in total, it would only be used around 20 times between 1931 and 1959 when the last droving run was completed. None of the larger station owners used the track as it was found that only 600 head of cattle could be supported at a time, which was 200 less than was estimated when first completed. As Carnegie had accurately reported in 1896, the track was impractical for cattle drives.

During the Second World War the track was upgraded at considerable expense in case it was needed for an evacuation of the north if Australia was invaded. Including horse drives there have been only 37 recorded drives between 1910 and the last run in 1959.

Traverses
In the 1950s horses became scarce in the Kimberley as widespread losses were caused by "walkabout poison". This led to the stock route being used to drove horses north from around the Norseman area where they were sold to the stations. Wally Dowling, a drover who had made nine droves along the stock route took what was probably the last group of horses northwards along the route in September 1951. In 1968 the entire length of the track was driven for the first time by surveyors Russell Wenholz and David Chudleigh, and Noel Kealley.

In 1972, before the route was regularly negotiated in four-wheel drives, ambitious attempts to complete it on foot took place. A New Zealander, Murray Rankin, and two English brothers, John and Peter Waterfall, fashioned homemade trolleys from bicycle wheels and metal tubing, and began their attempt starting from Wiluna in early June 1972. First John and then Peter turned back, but Rankin continued to Kumpupintil Lake, then called Lake Disappointment, before being forced to abandon the attempt. The remains of one of their trolleys lie 19 km north of well 15.

In 1973 Rankin tried again, this time starting from Old Halls Creek with Englishman John Foulsham. This time they had professionally built trolleys with motor-cycle wheels. The walk began on 1 June. Soon after reaching Godfrey's Tank they were unable to pull the trolleys over the high sand hills. They left them and walked on to Lake Tobin and there abandoned the attempt and returned to Halls Creek.

Three years later, in 1976, Rankin achieved his ambition to walk the stock route. After driving the route in a Land Rover and establishing food depots along the way, he set out from Halls Creek on 12 July 1976 with three other bushwalkers, Ralph Barraclough, Kathy Burman and Rex Shaw. Barraclough turned back after becoming ill, but the others completed the journey in just under three months.

In 1974, the first motorcycle crossing from Wiluna to Billiluna was achieved by Paul Allardyce, Colin Fitzgerald and Andy Bowman. They had air support flown by John Fitzgerald and Phil Schubert.

In 1977, the first commercial tour completed the drive.

During the 1980s fuel dumps were created and adventurous travellers became interested in the history of the track and the challenge to drive it.

In 1985, a Beach Buggy driven by Gordon Hayes, became the first two-wheel drive vehicle to complete the CSR under its own power. A support crew carried the fuel.

In 1991, a Citroen 2CV, driven by Rupert Backford and Mathew Rawlings, completed the CSR with a support crew towing the car over many of the dunes.

In 1993 long-distance walker Drew Kettle walked the route.

In 1997 Robin Rishworth cycled, with the aid of food drops, in just less than 27 days, and is considered to be the first modern day solo cyclist.

In 2004 Kate Leeming, as part of a longer trek, completed the route with the aid of a support vehicle.

In 2005 Jakub Postrzygacz became the first person to traverse the entire track without either support or the use of food drops, travelling alone by fatbike for 33 days. With large tyres and a single-wheel trailer, he carried all his food with him and replenished his water at wells.

In 2016 Sam Mitchell towed an array of solar panels behind his fatbike. This was the first time a solar powered vehicle traversed the complete length of the route.

Tourism
The Canning Stock route is considered one of the world's great four-wheel drive adventures. Apart from keeping the track open, the route is not maintained. Some wells have been restored but others are in ruins and unusable. While quite a few travellers successfully make the trip, it still requires substantial planning and a convoy of well-equipped four-wheel drives or equivalent vehicles, and is only practical during the cooler months. Fuel drops typically need to be organised in advance and the 1850 km trip will take two to three weeks. Fuel is now available at Kunawarritji Community near well 33 and Parnngurr Community near well 22.

The Kuju Wangka committee of the Yanunijarra Aboriginal Corporation closed the Canning Stock Route to tourists in March 2020 because of the COVID-19 pandemic. They reopened it on 14 June 2022.

Aboriginal perspective
The history of the Canning Stock Route has been well documented from the colonial perspective – accounts of European explorers, drovers, prospectors and law enforcers – but increasingly the Aboriginal history of the track is also being recognised, and Aboriginal people are keen to have their story told. "We wanna tell you fellas 'bout things been happening in the past that hasn't been recorded, what old people had in their head. No pencil and paper. The white man history has been told and it's today in the book. But our history is not there properly. We've got to tell 'em through our paintings." Archaeologists now believe that the Western Desert has been occupied for around 30,000 years. For Aboriginal people, the history of the stock route is therefore part of a much older story. They have recorded this story, including the changes brought about by the construction of the stock route, through oral and artistic traditions.

The building of the stock route impacted on the cultural and social life of the more than 15 Aboriginal language groups that have a "cultural, familial or historical connection to the route and its custodians, or to sites along the major Dreaming tracks or songlines". Some Dreaming tracks exist within the Country of a single language group, but others cross the territory of many groups and the major Dreaming tracks often mark the territorial boundaries of the Countries they cross. The stock route, and the people and stock it brought with it, inevitably interrupted traditional patterns of movement and connection to Country.

While many Aboriginal people made a determined effort to avoid contact with the people the stock route brought into their Country, the route became a path out of the desert for others. At different times, and for different reasons, people moved away to the outskirts of towns, to pastoral stations and church missions. Many found work with the drovers using the stock route and successful droves relied on the skill of these Aboriginal stockmen and women. Others left looking for more reliable sources of food and water, especially in times of drought, while some were drawn to the changes taking place around the edges of the desert or motivated by a desire to join family already living elsewhere.

Rock art project
There are a large number of Aboriginal rock paintings and carvings along the stock route. As more and more people visit the area each year, custodians of the Western Desert have become concerned about the protection and management of Aboriginal sites along the route. In 2007, researchers from the Australian National University began a project to draw up the first comprehensive plan of management for the entire Canning Stock Route. The project aimed to develop a series of modules to inform detailed guides and signs for visitors, while also protecting sites that have special significance for Indigenous peoples.

The Canning Stock Route Project
The Canning Stock Route has a strong connection to the story of Aboriginal art in the Western Desert. When droving along the stock route led to many family groups dispersing to the edges of the desert, communities were established in missions, towns, stations and settlements, and it was here that contemporary painting movements flourished. In 2006, West Australian independent cultural organisation Form instigated a contemporary arts and cultural initiative to "explore the complex history of the Canning Stock Route through the prism of contemporary Aboriginal art". Partnerships among nine art centres and communities with direct connections to the stock route region were set up. The project involved several years of research by Form in collaboration with Aboriginal artists and their art centres and organisations. A major part of the project's program of bush work was a six-week, 1850 km desert journey from Wiluna to Billiluna. During this trip, and in follow-up workshops and other trips, 80 artists created a collection of paintings, contemporary cultural objects and documentary material.

The historical and artistic value of the project was recognised in 2008 when the National Museum of Australia decided to acquire the entire Canning Stock Route Project collection. The language groups identified during the project, as being crossed by the stock route, or adjacent to it are identified as: (from the south)

 * Kiyajarra
 * Putijarra
 * Kartujarra
 * Manyjilyjarra
 * Warnman
 * Wangkajunga
 * Nyangajarra
 * Juwaliny
 * Walmajarri
 * Kukatja
 * Djaru

The Canning Stock Route Collection
The National Museum of Australia acquired a significant collection of artworks and other material collected by the 60 artists who travelled along the Canning Stock Route on a six-week return to country trip in 2007 as part of the Canning Stock Route Project. The Canning Stock Route collection includes over 100 works of art, 120 oral histories, historical research, social and cultural data, artists' biographies, 20,000 photographs and over 200 hours of film footage.

One of the key aims of the Canning Stock Route Project was the development of a travelling exhibition. The National Museum of Australia committed to assisting Form to develop an exhibition. Yiwarra Kuju (One Road) – The Canning Stock Route, a joint initiative between the National Museum of Australia and Form, was held at the museum from July 2010 to January 2011. The exhibition used works of art and stories to tell the story of the stock route's impact on Aboriginal people from an Aboriginal perspective. When it closed in January 2011, Yiwarra Kuju – The Canning Stock Route had been the most successful exhibition in the history of the Museum, with over 120,000 visitors.

Journey distances
The nearest capital city to the Wiluna starting point of the route is Perth, 958 km south west of Wiluna by road. Then to return to Perth via sealed roads from Halls Creek it is 2857 km; including the Canning route this gives a total driving distance of 5665 km.

title: Canning Stock Route


text:
Coat of arms

A coat of arms is a heraldic visual design on an escutcheon (i.e., shield), surcoat, or tabard (the latter two being outer garments). The coat of arms on an escutcheon forms the central element of the full heraldic achievement, which in its whole consists of a shield, supporters, a crest, and a motto. A coat of arms is traditionally unique to the armiger (e.g. an individual person, family, state, organization, school or corporation). The term "coat of arms" itself, describing in modern times just the heraldic design, originates from the description of the entire medieval chainmail "surcoat" garment used in combat or preparation for the latter.

Rolls of arms are collections of many coats of arms, and since the early Modern Age centuries, they have been a source of information for public showing and tracing the membership of a noble family, and therefore its genealogy across time.

History
Heraldic designs came into general use among European nobility in the 12th century. Systematic, heritable heraldry had developed by the beginning of the 13th century. Exactly who had a right to use arms, by law or social convention, varied to some degree between countries. Early heraldic designs were personal, used by individual noblemen (who might also alter their chosen design over time). Arms become hereditary by the end of the 12th century, in England by King Richard I during the Third Crusade (1189–1192).

Burgher arms were used in Northern Italy in the second half of the 14th century, and in the Holy Roman Empire by the mid 14th century. In the late medieval period, use of arms spread to the clergy, to towns as civic identifiers, and to royally chartered organizations such as universities and trading companies. The arts of vexillology and heraldry are closely related.

The term coat of arms itself in origin refers to the surcoat with heraldic designs worn by combatants, especially in the knightly tournament, in Old French cote a armer. The sense is transferred to the heraldic design itself in Middle English, in the mid-14th century.

Despite no common, enforceable widespread regulation, heraldry has remained consistent across Europe, where tradition alone has governed the design and use of arms. Some nations, such as England and Scotland, still maintain the same heraldic authorities which have traditionally granted and regulated arms for centuries and continue to do so in the present day. In England, for example, the granting of arms is and has been controlled by the College of Arms. Unlike seals and other general emblems, heraldic "achievements" have a formal description called a blazon, which uses vocabulary that allows for consistency in heraldic depictions. In the present day, coats of arms are still in use by a variety of institutions and individuals: for example, many European cities and universities have guidelines on how their coats of arms may be used, and protect their use as trademarks as any other unique identifier might be. Many societies exist that also aid in the design and registration of personal arms.

Heraldry has been compared to modern corporate logos.

French heraldry
The French system of heraldry greatly influenced the British and Western European systems. Much of the terminology and classifications are taken from it. However, with the fall of the French monarchy (and later Empire) there is not currently a Fons Honorum (power to dispense and control honors) to strictly enforce heraldic law. The French Republics that followed have either merely affirmed pre-existing titles and honors or vigorously opposed noble privilege. Coats of arms are considered an intellectual property of a family or municipal body. Assumed arms (arms invented and used by the holder rather than granted by an authority) are considered valid unless they can be proved in court to copy that of an earlier holder.

British heraldry
In the heraldic traditions of England and Scotland, an individual, rather than a family, had a coat of arms. In those traditions coats of arms are legal property transmitted from father to son; wives and daughters could also bear arms modified to indicate their relation to the current holder of the arms. Undifferenced arms are used only by one person at any given time. Other descendants of the original bearer could bear the ancestral arms only with some difference: usually a colour change or the addition of a distinguishing charge. One such charge is the label, which in British usage (outside the Royal Family) is now always the mark of an heir apparent or (in Scotland) an heir presumptive. Because of their importance in identification, particularly in seals on legal documents, the use of arms was strictly regulated; few countries continue in this today. This has been carried out by heralds and the study of coats of arms is therefore called "heraldry". In time, the use of arms spread from military entities to educational institutes, and other establishments.

In Scotland, the Lord Lyon King of Arms has criminal jurisdiction to control the use of arms. In England, Northern Ireland and Wales the use of arms is a matter of civil law and regulated by the College of Arms and the High Court of Chivalry.

In reference to a dispute over the exercise of authority over the Officers of Arms in England, Arthur Annesley, 1st Earl of Anglesey, Lord Privy Seal, declared on 16 June 1673 that the powers of the Earl Marshal were "to order, judge, and determine all matters touching arms, ensigns of nobility, honour, and chivalry; to make laws, ordinances, and statutes for the good government of the Officers of Arms; to nominate Officers to fill vacancies in the College of Arms; to punish and correct Officers of Arms for misbehaviour in the execution of their places". It was further declared that no patents of arms or any ensigns of nobility should be granted and no augmentation, alteration, or addition should be made to arms without the consent of the Earl Marshal.

Irish heraldry
In Ireland the usage and granting of coats of arms was strictly regulated by the Ulster King of Arms from the office's creation in 1552. After Irish independence in 1922 the office was still functioning and working out of Dublin Castle. The last Ulster King of Arms was Sir Nevile Rodwell Wilkinson [Ulster King of Arms 1908–1940], who held it until his death in 1940. At the Irish government's request, no new King of Arms was appointed. Thomas Ulick Sadleir, the Deputy Ulster King of Arms, then became the Acting Ulster King of Arms. He served until the office was merged with that of Norroy King of Arms in 1943 and stayed on until 1944 to clear up the backlog.An earlier Ireland King of Arms was created by King Richard II in 1392 and discontinued by King Henry VII in 1487. It did not grant many coats of arms – the few it did grant were annulled by the other Kings of Arms because they encroached upon their jurisdictions. Its purpose was supposedly to marshal an expedition to fully conquer Ireland that never materialized. Since 1 April 1943 the authority has been split between the Republic of Ireland and Northern Ireland. Heraldry in the Republic of Ireland is regulated by the Government of Ireland, by the Genealogical Office through the Office of the Chief Herald of Ireland. Heraldry in Northern Ireland is regulated by the British Government by the College of Arms through the Norroy and Ulster King of Arms.

German heraldry

The heraldic tradition and style of modern and historic Germany and the Holy Roman Empire – including national and civic arms, noble and burgher arms, ecclesiastical heraldry, heraldic displays, and heraldic descriptions – stand in contrast to Gallo-British, Latin and Eastern heraldry, and strongly influenced the styles and customs of heraldry in the Nordic countries, which developed comparatively late.

Scandinavian heraldry
In the Nordic countries, provinces, regions, cities, and municipalities have coats of arms. These are posted at the borders and on buildings containing official offices, as well as used in official documents and on the uniforms of municipal officers. Arms may also be used on souvenirs or other effects, given that an application has been granted by the municipal council.

Other national traditions

At a national level, "coats of arms" were generally retained by European states with constitutional continuity of more than a few centuries, including constitutional monarchies like Denmark as well as old republics like San Marino and Switzerland.

In Italy the use of coats of arms was only loosely regulated by the states existing before the unification of 1861. Since the Consulta Araldica, the college of arms of the Kingdom of Italy, was abolished in 1948, personal coats of arms and titles of nobility, though not outlawed, are not recognised.

Coats of arms in Spain were generally left up to the owner themselves, but the design was based on military service and the heritage of their grandparents. In France, the coat of arms is based on the Fleur-de-lys and the Rule of Tinctures used in English heraldry as well.

Canada
The monarch of Canada's prerogative to grant armorial bearings has been delegated to the Governor General of Canada. Canada has its own Chief Herald and Herald Chancellor. The Canadian Heraldic Authority, the governmental agency which is responsible for creating arms and promoting Canadian heraldry, is situated at Rideau Hall.

United States
The Great Seal of the United States uses on the obverse as its central motif a heraldic achievement described as being the arms of the nation. The seal, and the armorial bearings, were adopted by the Continental Congress on 20 June 1782, and is a shield divided palewise into thirteen pieces, with a blue chief, which is displayed upon the breast of an American bald eagle. The crest is thirteen stars breaking through a glory and clouds, displayed with no helm, torse, or mantling (unlike most European precedents). Only a few of the American states have adopted a coat of arms, which is usually designed as part of the respective state's seal. Vermont has both a state seal and a state coat of arms that are independent of one another (though both contain a pine tree, a cow and sheaves of grain); the seal is used to authenticate documents, whilst the heraldic device represents the state itself.

Ecclesiastic heraldry

The Vatican City State and the Holy See each have their own coat of arms. As the papacy is not hereditary, its occupants display their personal arms combined with those of their office. Some popes came from armigerous (noble) families; others adopted coats of arms during their career in the Church. The latter typically allude to their ideal of life, or to specific pontifical programmes. A well-known and widely displayed example in recent times was Pope John Paul II's arms. His selection of a large letter M (for the Virgin Mary) was intended to express the message of his strong Marian devotion. Roman Catholic dioceses are also each assigned a coat of arms, as are basilicas or papal churches, the latter usually displaying these on the building. These may be used in countries which otherwise do not use heraldic devices. In countries like Scotland with a strong statutory heraldic authority, arms will need to be officially granted and recorded.

Flags and banners
Flags are used to identify ships (where they are called ensigns), embassies and such, and they use the same colors and designs found in heraldry, but they are not usually considered to be heraldic. A country may have both a national flag and a national coat of arms, and the two may not look alike at all. For example, the flag of Scotland (St Andrew's Cross) has a white saltire on a blue field, but the royal arms of Scotland has a red lion within a double tressure on a gold (or) field.

Modern national emblems
Among the states ruled by communist regimes, emblems resembling those of the Soviet states were adopted in all the Warsaw Pact states except Czechoslovakia and Poland. Since 1986–1989, some of the ex-Communist states, such as Russia, have reused their original pre-communist heraldry, often with only the symbols of monarchy removed. Other countries such as Belarus have retained their communist coats of arms or at least kept some of the old heraldry.

With the independence of the modern nation states of the Arab World from the First World War onwards, European traditions of heraldry were partially adopted for state emblems. These emblems often involve the star and crescent symbol taken from the Ottoman flag. Other commonly seen symbols are birds, chiefly the Eagle of Saladin, and the Hawk of Quraish. These symbols can be found on the coat of arms of Egypt, and Syria, amongst others.

Sub-Saharan African flags and emblems after decolonisation often chose emblems based on regional traditions or wildlife. Symbols of a ritual significance according to local custom were generally favoured, such as the leopard in the arms of Benin, Malawi, Somalia, the Democratic Republic of the Congo and, in the form of the black panther, of Gabon.

In Kenya, the Swahili word Harambee (lit. "Let us come together") is used as a motto in the country's coat of arms. In Botswana and Lesotho, meanwhile, the word Pula (lit. "Rain") is used in like fashion.

In the coat of arms of Eswatini, a lion and an elephant serve as supporters. They are each intended to represent the king and the queen mother respectively, the nation's joint heads of state.

Comparable traditions outside of Europe

Japanese emblems, called kamon (often abbreviated "mon"), are family badges which often date back to the 7th century, and are used in Japan today. The Japanese tradition is independent of the European, but many abstract and floral elements are used.

title: Coat of arms


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Ernst Mach

Ernst Waldfried Josef Wenzel Mach (, ; 18 February 1838 – 19 February 1916) was an Austrian physicist and philosopher, who contributed to the physics of shock waves. The ratio of the speed of a flow or object to that of sound is named the Mach number in his honour. As a philosopher of science, he was a major influence on logical positivism and American pragmatism. Through his criticism of Isaac Newton's theories of space and time, he foreshadowed Albert Einstein's theory of relativity.

Early life
Mach was born in Chrlice (Chirlitz), Moravia, Austrian Empire (part of Brno, in the Czech Republic). His father, who had graduated from Charles-Ferdinand University in Prague, acted as tutor to the noble Brethon family in Zlín in eastern Moravia. His grandfather, Wenzl Lanhaus, an administrator of the Chirlitz estate, was also master builder of the streets there. His activities in that field later influenced Ernst Mach's theoretical work. Some sources give Mach's birthplace as Tuřany (Turas, also part of Brno), the site of the Chirlitz registry office. It was there that Mach was baptised by Peregrin Weiss. Mach later became a socialist and an atheist, but his theory and life was sometimes compared to Buddhism. Heinrich Gomperz called Mach the "Buddha of Science" because of his phenomenalist approach to the "Ego" in his Analysis of Sensations. Up to the age of 14, Mach was educated at home by his parents. He then entered a gymnasium in Kroměříž (Kremsier), where he studied for three years. In 1855 he became a student at the University of Vienna, where he studied physics and for one semester medical physiology, receiving his doctorate in physics in 1860 under Andreas von Ettingshausen with the thesis Über elektrische Ladungen und Induktion, and his habilitation the following year. His early work focused on the Doppler effect in optics and acoustics.

Professional research
In 1864, he took a job as professor of mathematics at the University of Graz after he had turned down the position of a chair in surgery at the University of Salzburg to do so, and in 1866 he was appointed professor of physics. During that period, Mach continued his work in psycho-physics and in sensory perception. In 1867, he took the chair of experimental physics at the Charles-Ferdinand University, where he stayed for 28 years before returning to Vienna.

Mach's main contribution to physics involved his description and photographs of spark shock-waves and then ballistic shock-waves. He described how when a bullet or shell moved faster than the speed of sound, it created a compression of air in front of it. Using schlieren photography, he and his son Ludwig photographed the shadows of the invisible shock waves. During the early 1890s Ludwig invented a modification of the Jamin interferometer that allowed for much clearer photographs. But Mach also made many contributions to psychology and physiology, including his anticipation of gestalt phenomena, his discovery of the oblique effect and of Mach bands, an inhibition-influenced type of visual illusion, and especially his discovery of a non-acoustic function of the inner ear that helps control human balance.

One of the best-known of Mach's ideas is the so-called Mach principle, the physical origin of inertia. This was never written down by Mach, but was given a graphic verbal form, attributed by Philipp Frank to Mach: "When the subway jerks, it's the fixed stars that throw you down."

Mach also became well known for his philosophy, developed in close interplay with his science. Mach defended a type of phenomenalism recognizing only sensations as real. That position seemed incompatible with the view of atoms and molecules as external mind-independent things. He famously declared, after an 1897 lecture by Ludwig Boltzmann at the Imperial Academy of Science in Vienna, "I don't believe that atoms exist!" From about 1908 to 1911, Max Planck criticised Mach's reluctance to acknowledge the reality of atoms as incompatible with physics. Einstein's 1905 work on Brownian motion showed that the statistical fluctuations of atoms allowed measurement of their existence without direct individuated sensory evidence marked a turning point in the acceptance of atomic theory. Some of Mach's criticisms of Newton's position on space and time influenced Einstein, but later, Einstein realised that Mach was basically opposed to Newton's philosophy and concluded that his physical criticism was not sound. In 1898, Mach survived a paralytic stroke, and in 1901, he retired from the University of Vienna and was appointed to the upper chamber of the Austrian Parliament. On leaving Vienna in 1913, he moved to his son's home in Vaterstetten, near Munich, where he continued writing and corresponding until his death in 1916, one day after his 78th birthday.

Physics
Most of Mach's initial studies in experimental physics concentrated on the interference, diffraction, polarization and refraction of light in different media under external influences. From there followed explorations in supersonic fluid mechanics. Mach and physicist-photographer Peter Salcher presented their paper on this subject in 1887; it correctly describes the sound effects observed during the supersonic motion of a projectile. They deduced and experimentally confirmed the existence of a shock wave of conical shape, with the projectile at the apex. The ratio of the speed of a fluid to the local speed of sound vp/vs is called the Mach number after him. It is a critical parameter in the description of high-speed fluid movement in aerodynamics and hydrodynamics. Mach also contributed to cosmology the hypothesis known as Mach's principle.

Empirio-criticism
From 1895 to 1901, Mach held a newly created chair for "the history and philosophy of the inductive sciences" at the University of Vienna. In his historico-philosophical studies, Mach developed a phenomenalistic philosophy of science that became influential in the 19th and 20th centuries. He originally saw scientific laws as summaries of experimental events, constructed for the purpose of making complex data comprehensible, but later emphasized mathematical functions as a more useful way to describe sensory appearances. Thus, scientific laws, while somewhat idealized, have more to do with describing sensations than with reality as it exists beyond sensations.

The goal which it (physical science) has set itself is the simplest and most economical abstract expression of facts.

When the human mind, with its limited powers, attempts to mirror in itself the rich life of the world, of which it itself is only a small part, and which it can never hope to exhaust, it has every reason for proceeding economically.

In reality, the law always contains less than the fact itself, because it does not reproduce the fact as a whole but only in that aspect of it which is important for us, the rest being intentionally or from necessity omitted.

In mentally separating a body from the changeable environment in which it moves, what we really do is to extricate a group of sensations on which our thoughts are fastened and which is of relatively greater stability than the others, from the stream of all our sensations.

Suppose we were to attribute to nature the property of producing like effects in like circumstances; just these like circumstances we should not know how to find. Nature exists once only. Our schematic mental imitation alone produces like events.

Mach's positivism influenced many Russian Marxists, such as Alexander Bogdanov. In 1908, Lenin wrote a philosophical work, Materialism and Empirio-criticism, in which he criticized Machism and the views of "Russian Machists". His main criticisms were that Mach's philosophy led to solipsism and to the absurd conclusion that nature did not exist before humans:

If bodies are "complexes of sensations," as Mach says, or "combinations of sensations," as Berkeley said, it inevitably follows that the whole world is but my idea. Starting from such a premise it is impossible to arrive at the existence of other people besides oneself: it is the purest solipsism.

...if [Mach] does not admit that the "sensible content" is an objective reality, existing independently of us, there remains only a "naked abstract" I, an I infallibly written with a capital letter and italicised, equal to "the insane piano, which imagined that it was the sole existing thing in this world." If the "sensible content" of our sensations is not the external world then nothing exists save this naked I engaged in empty "philosophical" acrobatics.

Empirio-criticism is the term for the rigorously positivist and radically empiricist philosophy established by the German philosopher Richard Avenarius and further developed by Mach, Joseph Petzoldt, and others, that claims that all we can know is our sensations and that knowledge should be confined to pure experience.

In accordance with empirio-critical philosophy, Mach opposed Boltzmann and others who proposed an atomic theory of physics. Since one cannot observe things as small as atoms directly, and since no atomic model at the time was consistent, the atomic hypothesis seemed unwarranted to Mach, and perhaps not sufficiently "economical". Mach had a direct influence on the Vienna Circle philosophers and logical positivism in general.

Several principles are attributed to Mach that distill his ideal of physical theorization, called "Machian physics":
 * 1) It should be based entirely on directly observable phenomena (in line with his positivistic leanings)
 * 2) It should completely eschew absolute space and time in favor of relative motion
 * 3) Any phenomena that seem attributable to absolute space and time (e.g., inertia and centrifugal force) should instead be seen as emerging from the distribution of matter in the universe.

The last is singled out, particularly by Einstein, as "the" Mach's principle. Einstein cited it as one of the three principles underlying general relativity. In 1930, he wrote, "it is justified to consider Mach as the precursor of the general theory of relativity", though Mach, before his death, apparently rejected Einstein's theory. Einstein knew that his theories did not fulfill all Mach's principles, and neither has any subsequent theory, despite considerable effort.

Phenomenological constructivism
According to Alexander Riegler, Mach's work was a precursor to the influential perspective known as constructivism. Constructivism holds that all knowledge is constructed rather than received by the learner. He took an exceptionally non-dualist, phenomenological position. The founder of radical constructivism, Ernst von Glasersfeld, gave a nod to Mach as an ally.

On the other hand, there is also a reasonable case for viewing Mach simply as an empiricist and a precursor of the logical empiricists and the Vienna Circle. On this view, the purpose of science is to detail functional relationships between observations: "The goal which it (physical science) has set itself is the simplest and most economical abstract expression of facts."

Physiology
In 1873, independently of each other, Mach and the physiologist and physician Josef Breuer discovered how the sense of balance (i.e., the perception of the head's imbalance) functions, tracing its management by information the brain receives from the movement of a fluid in the semicircular canals of the inner ear. That the sense of balance depends on the three semicircular canals was discovered in 1870 by the physiologist Friedrich Goltz, but Goltz did not discover how the balance-sensing apparatus functions. Mach devised a swivel chair to test his theories, and Floyd Ratliff has suggested that this experiment may have paved the way to Mach's critique of a physical conception of absolute space and motion.

Psychology

In the area of sensory perception, psychologists remember Mach for the optical illusion called Mach bands. The effect exaggerates the contrast between edges of the slightly differing shades of gray as soon as they touch, by triggering edge-detection in the human visual system.

More clearly than anyone before or since, Mach made the distinction between what he called physiological (specifically visual) and geometrical spaces.

Mach's views on mediating structures inspired B. F. Skinner's strongly inductive position, which paralleled Mach's in the field of psychology.

Eponyms
In homage his name was given to:
 * 3949 Mach, an asteroid
 * Mach, a lunar crater
 * Mach bands, an optical illusion
 * Mach diamonds, seen in supersonic exhausts
 * Mach Five, the car used by Speed Racer
 * Mach number, the unit for speed relative to the speed of sound

title: Ernst Mach