PARTICLESS

  

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PARTICLESS

Specialty Definition: Grammatical particle

(From Wikipedia, the free Encyclopedia)

A particle is a word that is normally uninflected, and often has little clear meaning, but has an important function in a sentence or phrase, and is therefore called a function word. It is distinct from the other words in the sentence, but may reflect the attitude or even the mood of the speaker or narrator of the text, or may act as a sentence connector to the previous sentence or clause.

In Japanese and Korean (which are unrelated languages but have almost identical grammars), particles are used to mark nouns according to their case or their role (subject, object, complement, or topic) in a sentence or clause. In Korean, particles are considered as a distinct part of speech. The examples below use English particles.

Many linguists classify adverbs and prepositions as particles. Conjunctions may also count as particles when they correlate clauses in a sentence.
Interjections expressing attitude, mood, or state of mind may also be classified as particles. Yet another type of particle is the sentence substitutes. Sentence substitutes are sometimes single words that can stand on their own and take the place of a whole sentence, such as "Hello", or "Goodbye", or "Yes".
Finally, the word "to" in an infinitive is considered to be a particle.

As can be seen, the greater number of particles are relatively short words. However, there are also "particle phrases" (adverbial phrases), such as "of course", "as it were", etc., which remain unchanged and separate from other words within the sentence, although they may contain inflected elements, such as "were". Also the so-called tag questions, such as "isn't it(?)", "won't he(?)", "doesn't it(?)", etc. which generally go at the end of the sentence, fall under this category, in that they have a reinforcing or reassuring function, or a sentence connection function, or even indicate the mood of attitude of the speaker/narrator.

Also, words such as "the" (the articles with noun); the "to" (in infinitives) and the determiners "more", "most", "less", "least" (in comparatives and superlatives should be regarded as particles as they themselves are not inflected, but belong to other words that are. Yet it must be conceded that they are not isolated in the way particles normally are, since they are part of an over-all grammatical inflection.

However, if particles change into nouns or verbs, they take on the affixes of the inflections of these nouns and verbs, such as in "ifs and buts", or "humming and hawing" (of the interjection "hum").

Grammatical particles are particularly important in colloquial speech, which probably would not be able to convey many special shades of meaning without them. It is the subtle use of particles in phrases such as "now then, what's all this"; "so what"; "you spoke to her, then"?; "anyway, there I was"; "still, it could have been a lot worse"; and many others that make communication in colloquial speech so rich.

List of particles:

Coordinating Conjunctions: You can remember this with the handy mnemonic FANBOYS.

Some use and/or in writing.

Subordinating Conjunction:

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Particle physics

(From Wikipedia, the free Encyclopedia)

Particle physics is a branch of physics that studies the elementary constituents of matter and radiations, and the interactions between them. It is also called high energy physics, because many elementary particles do not occur independently in Nature, and can only be detected during energetic collisions of larger particles, as is done in particle accelerators.

Modern particle physics research is focused on subatomic particles, which are smaller than atoms. These include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles, made up of quarks), as well as particles produced by radiative and scattering processes, such as photons, neutrinos, and muons.

Strictly speaking, the term particle is something of a misnomer. The objects studied by particle physics obey the principles of quantum mechanics. As such, they exhibit wave-particle duality, displaying particle-like behavior under certain experimental conditions and wave-like behavior in others. Theoretically, they are described neither as waves nor as particles, but as state vectors in an abstract Hilbert space. For a more detailed explanation, see quantum field theory. Following the convention of particle physicists, we will use "elementary particles" to refer to objects such as electrons and photons, with the understanding that these "particles" display wave-like properties as well.

All the particles observed to date have been catalogued in a quantum field theory called the Standard Model, which is often regarded as particle physics' best achievement to date. The model contains 47 species of elementary particles, some of which can combine to form composite particles, accounting for the hundreds of other species of particles discovered since the 1960s. The Standard Model has been found to agree with almost all the experimental tests conducted to date. However, most particle physicists believe that it is an incomplete description of Nature, and that a more fundamental theory awaits discovery. In recent years, measurements of neutrino mass have provided the first experimental deviations from the Standard Model.

Particle physics has had a large impact on philosophy of science. The reductionist ideas that motivates much of the work in this field has been criticized by various philosophers and scientists. Part of the debate is described below.

History of particle physics

The idea that matter is composed on elementary particles dates to at least the 6th century BC. The philosophical doctrine of "atomism" was studied by ancient Greek philosophers such as Leucippus, Democritus, and Epicurus. Although Isaac Newton in the 17th century thought that matter was made up of particles, it was John Dalton who formally stated in 1802 that everything is made from tiny atoms.

Dmitri Mendeleev's first periodic table in 1869 helped cement the view, prevalent throughout the 19th century, that matter was made of atoms. Work by J.J. Thomson established that atoms are composed of light electrons and massive protons. Ernest Rutherford established that the protons are concentrated in a compact nucleus. The nucleus was initially thought to be composed of protons and confined electrons (in order to explain the difference between nuclear charge and mass number), but was later found to be composed of protons and neutrons.

The 20th century explorations of nuclear physics and quantum physics, culminating with proofs of nuclear fission and nuclear fusion, gave rise to an active industry of generating one atom from another, even rendering possible (although not feasible economically) the transmutation of lead into gold. These theories successfully predicted nuclear weapons.

Throughout the 1950s and 1960s, a bewildering variety of particles was found in scattering experiments. This was referred to as the "particle zoo". This term was deprecated after the formulation of the Standard Model during the 1970s in which the large number of particles was explained as combinations of a (relatively) small number of fundamental particles.

The Standard Model of particle physics

The current state of the classification of elementary particles is called the "Standard Model". It describes the strong, weak, and electromagnetic fundamental forces, using mediating bosons known as "gauge bosons". The species of gauge bosons are the photon, W- and W+ and Z bosons, and the gluons. The model also contains 24 fundamental particles, which are the constituents of matter. Finally, it predicts the existence of a type of boson known as the Higgs boson, which has yet to be discovered.

Experimental particle physics

In Particle Physics, the major international collaborations are:

Many other particle accelerators exist.

Objections against particle physics as reductionism

Within physics itself, there are some objections to the extreme reductionist approach of attempting to explain everything in terms of elementary particles and their interaction. These objections are usually raised by solid state physicists. While the Standard Model itself is not challenged, it is held that testing and perfecting the model is not nearly as important as studying the emerging properties of atoms and molecules, and especially large statistical ensembles of those. These critics claim that even a complete knowledge of the underlying elementary particles will not give complete knowledge of atoms and molecules, knowledge that arguably is more important to us.

Reductionists typically claim that all progress in the sciences has involved reductionism to some extent.

Public policy and particle physics

Experimental results in particle physics are investigated using enormous particle accelerators which typically cost several billion dollars and require large amounts of government funding. Because of this, particle physics research involves issues of public policy.

Many have argued that the potential advances do not justify the money spent, and that in fact particle physics takes money away from more important research and education efforts. In 1993, the US Congress stopped the Superconducting Super Collider because of similar concerns, after $2 billion had already been spent on its construction. Many scientists, both supporters and opponents of the SSC, believe that the decision to stop construction of the SSC was due in part to the end of the Cold War which removed scientific competition with the Soviet Union as a rationale to spend large amounts of money on the SSC.

Some within the scientific community believe that particle physics has also been adversely affected by the aging population. The belief is that the aging population is much more concerned with immediate issues of their health and their parent's health and that this has driven scientific funding away from physics toward the biological and health sciences. In addition, many opponents question the ability of any single country to support the expense of particle physics results and fault the SSC for not seeking greater international funding.

Proponents of particle accelerators hold that the investigation of the most basic theories deserves adequate funding, and that this funding benefits other fields of science in various ways. They point out that all accelerators today are international projects and question the claim that money not spent on accelerators would then necessarily be used for other scientific or educational purposes.

See also

External Links

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Subatomic particle

(From Wikipedia, the free Encyclopedia)

In physics, a subatomic particle is a particle smaller than an atom. These include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles, made up of quarks), as well as particles produced by radiative and scattering processes, such as photons, neutrinos, and muons. Many of the particles that have been discovered and studied are actually not encountered naturally; they have to be produced during scattering processes in particle accelerators. The study of subatomic particles is the most active branch of particle physics.

The electron (symbol e-) is present in all atoms; it has a mass of 1/1836 the mass of a hydrogen atom, and a negative charge. Protons (symbol p+) are also present in all atoms; a proton is about the same mass as a hydrogen atom and carries positive charge equal in magnitude but opposite in sign to electron. Neutrons (symbol n) are electrically neutral and have about the same mass as a proton.

Hadrons are particles composed of quarks. Examples include baryons and mesons. Baryons are composed of three quarks, usually of the "up" or "down" variety. They all have a large rest mass for subatomic particles. Examples of baryons are protons and neutrons.

Types of Baryons (selection)

NameQuarksMass (GeV)
Protonuud0.938
Neutronudd0.940
uds1.116
uus1.189
uds1.192
dds1.197
uuu1.232
sss1.672
udc2.273

Mesons are composed of a normal quark and an antiquark, which causes the baryon number to go to zero. None of these are very stable, but have half lives on the order of nanoseconds. They have a rest mass starting with 140 MeV for the lightest mesons, the pion.

Leptons contain no quarks, but are small irreducible particles (no smaller constituent is currently known). Some have no rest mass, while others have very large rest mass. Types of leptons include electrons, muons, tauons and neutrinos.

Also See

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INDEX

1. Bibliography


  

Copyright © Philip M. Parker, INSEAD. Terms of Use.