Implosion (pronoubced im-ploh-zhuhn)
(1) The act of imploding; a bursting inward
(opposite of explosion).
(2) In phonetics, the occlusive phase of stop
consonants; the nasal release heard in the common pronunciation of eaten,
sudden, or mitten, in which the vowel of the final syllable is greatly reduced.
(3) The ingressive release of a suction stop.
(4) In clinical psychiatry, a type of behavior
therapy in which the patient is repeatedly subjected to anxiety-arousing
stimuli while the therapist attempts to extinguish the patient's anxiety and
anxious behavior and replace them with more appropriate responses.
1829: The construct (modelled on explosion) was im-
+ (ex)plosion. The im- prefix was from
the Latin im-, an assimilated form of
in- and used to express negation (not). The
prefix -in is quirky because it can act either to negate or intensify. The general rule is that when pre-pended to a
noun or adjective, it reinforces the quality signified and when pre-pended to
an adjective, it negates the meaning, the latter mostly in words borrowed from
French. The Latin prefix in- was from the Proto-Italic en-, from the primitive Indo-European n̥- (not),
the zero-grade form of the negative particle ne (not) and was akin to ne-,
nē & nī. In Modern English it is from the Middle English in-, from Old English in-
(in, into), from the Proto-Germanic in,
from the primitive Indo-European en. Plosion was a word from the jargon of phonetics meaning
the pronunciation of a consonant characterized by completely blocking the flow
of air through the mouth and was a derivative of explosion, first coming into
use in 1915–20 as a shortened form of explosion. Implosion, coined as an opposite of
explosion, was first published the Westminster
Review in 1829. There was a
technical need for the word because, in popular use, many chemical reactions
which resembled explosions were described thus, even though, as in the case of
a mixture of hydrogen and oxygen, instead of an enlargement of bulk, a positive
quantity, the result was is a negative one, tending towards a vacuum.
OceanGate’s diagram of Titan.
In response to the questions raised after it was
confirmed OceanGate's Titan submersible had suffered a catastrophic implosion
event, US Navy sources commented on the process: When a submarine collapses (implodes), the hull
material moves inward at a speed of around 1500 mph (2400 km/h) or 2200 feet
(670 m) per second and the time required for a complete collapse is about 1
millisecond. Typically, the human brain
responds instinctively to stimulus at about 25 milliseconds and those with
untypically fast reaction responses can begin to act at around 150
milliseconds. The atmosphere inside a
submarine contains a relatively high concentration of hydrocarbon vapors and
this contributes to the space behaving something like the compression cycle in
a very large diesel engine: The air auto-ignites and an explosion follows the
initial rapid implosion. A human in
these circumstances is transformed into large blobs of fats and these the
extreme temperature incinerates and turns to ash in little more than a second. Navy sources also expressed scepticism at the
desirability of constructing a hull from a mixture of materials (titanium and
carbon-fibre) in vessels operating at depths where the pressure is extreme (where
the wreck of the Titanic lies it’s some 400 times that which prevails at sea
level). The argument is that wherever the
two materials meet is the point at which, over time, a weakness is most likely
to form. Because the Titan's tubular hull was made from carbon fibre, it's thought that rather than behaving like the metals used in submarine construction, it would to some extent fragment although the nature of the disintegration won't be known until the wreckage is examined.
Engineers however noted the consequences of the explosion (for both machine and people) could differ greatly from the historic experiences of such events at depth because they all involved vessels made from metal which tends to retain its inherent integrity, even as the structural integrity of the construction fails. Additionally, many of the previous examples were spherical so the internal forces were equalized for the split-second during the critical event whereas Titan was tubular with what would, under the stresses imposed, become detachable titanium end-caps. Titan's hull was built from carbon-fibre which, under the specific pressure encountered would have behaved differently from metal and may have fragmented. The physics of all of this means the temperatures and dynamic forces experienced within Titan in that split-second may have been very different from the models generated by historic experience but until the wreckage and any human remains are examined, the details of the brief event will remain unclear. The incident however is anyway likely to discourage the use of carbon-fibre hulls in submersibles but whether it has any implications for use in aviation will be interesting. Building the fuselages of passenger airliners from carbon-fibre has many advantages and the stresses imposed are very different to those at depth but there is no real-world data to assess how the material will behave over the decades the airframes may operate.
Historically, the difference between a “submersible”
and a “submarine” was that a submersible was a vessel which operated usually on
the surface but was able to submerge for short periods for purposes such as launching
attacks on other vessels or attempting to avoid detection while a submarine was
able to operate underwater for extended periods. The definitions were (more or less) formalized
after 1945 when “true” submarines were developed, rendering obsolete the
traditional submersibles which gained their name as a clipping of “submersible
boat”. When nuclear propulsion was
adopted, the duration of the craft was extended further, the primary limitation
being the volume of food able to be stored.
The definitions have shifted somewhat although
traces of the older distinctions remain.
For practical purposes, a submarine is a large, complex vessel able to
undertake independent and extended underwater operations and although most
associated with navies, there are many civilian operators of submarines. In recent decades, submersibles have no
longer been designed for sustained surface use (although some of the recent
creations by drug smugglers appear to be exactly that) and are dedicated to and
optimized for the undersea environment. They
can be just about any type of vehicle or apparatus capable of operating
underwater, crewed or un-crewed and in an array of sizes and configurations for
use in fields such as scientific research, exploration or underwater
photography.
Implosions: Implosions do occasionally afflict storage tanks and the Mythbusters television series (past masters at explosions, on this one episode they forsook blowing stuff up and imploded something instead) attempted to create the conditions which “naturally” would provoke the phenomenon. It proved difficult and the implosion eventually was induced by artificially reducing the internal pressure.
Explosion (pronounced ik-sploh-zhuhn)
(1) An act or instance of exploding; a violent
release of energy resulting from a rapid chemical or nuclear reaction,
especially one that produces a shock wave, loud noise, heat, and light (or the
noise itself).
(2) A sudden, rapid, or great increase.
1615-1625: From the French explosion, from the Latin explōsiōnis, a genitive form of explōsio, from explōdo (I drive out by clapping) from explōdere (to explode), the construct being ex- (the prefix from Middle English from words borrowed from Middle French from the Latin ex (out of, from), from the primitive Indo-European eǵ- & eǵs- (out). It was cognate with the Ancient Greek ἐξ (ex) (out of, from), the Transalpine Gaulish ex- (out), the Old Irish ess- (out), the Old Church Slavonic изу (izu) (out), and the Russian из (iz) (from, out of)) + plōdo (I clap or I strike). The figurative of "going off with violence and noise" is from 1660s and some sources insist the sense of "rapid increase or development" wasn’t noted until 1953 when it came to be used in commerce (describing both the extraordinary proliferation of consumer products in what would later come to be known as the “affluent society” and spikes in demand). In the mid 1940s, the US conducted a number of nuclear weapon tests at Bikini Atoll in the South Pacific and when asked about his choice of “bikini” as the name for the fetching swimwear he trademarked (patent #19431) in 1946, the designer is reported to have at the time remarked he expected an "explosive commercial and cultural reaction" as dramatic as one of the Pentagon’s A-bombs. The figurative use thus dates from at least the 1940s and it would seem at least plausible that in that vein the word had been used for a long time, centuries of wars exposing millions to explosions surely likely to have inspired the linguistic imagination.
In Ancient Rome, at the conclusion of a play, the actors would turn to the audience and command plaudite! (literally "clap your hands!); that's the source of the English plaudits (a mark or expression of applause; praise bestowed) and of the idea of the plausible (something to be applauded). However, if the performance was a dud, the audience would explodo (the construct being ex- (out) + plaudo (clap), the idea being the actors is the dreadful performance would be "clapped off then stage" and as late as the seventeenth century the phrase persisted, surviving reports from critics recording "the crowd exploded him off the stage". Indeed, even now, phrases like "the theory has long been exploded" are still sometimes seen although whether the writer has in mind the idea or "clapped away" or "blown up" may be uncertain.
In figurative use, "implosion" and "explosion" frequently
are used to describe different events or phenomena, the former often related to
sudden and dramatic changes and while the latter can be used in this way, implosions
can be imagined as gradual things which unfold over a long time, sometimes even
years. That said, there are some “explosions”
which are regarded so only because of their peculiar context, such as the “Cambrian
explosion” which was sudden and dramatic only against the measure of the
evolutionary history of life on Earth. The
Cambrian Period, while a relatively brief period in the planet's four and a
half billion years-odd of existence still encompassed in excess of forty
million years (circa 540-485 million years ago). During this time, there was a remarkable
diversification and proliferation of complex multi-cellular life forms in the
oceans and it was “explosive” in the sense nothing like it had happened before
and in evolutionary terms, the appearance and diversification of an array of complex
organisms (including the first appearance of animal groups or phyla which
remain extant) was rapid indeed. Still,
that sort of figurative use of “explosion” tends to be restricted to evolutionary
biologists and their ilk and it’s more familiar when used to describe something
short & sharp like the rapid acceleration of a running back on the football
field. That would be over in seconds but
in sport, something like the innings of a cricketer might be called “explosive”
even if it unfolds over an hour or more.
It’s all a matter of context and literal explosions tend by their nature
to be fast, brief events.
Just about any dictionary would define an explosion as something like “a rapid and forceful outward expansion or release of energy”, conveying the idea of something bursting forth or erupting with great intensity, impact, or noise and that’s familiar from the event associated with impacts, bombs and even volcanic eruptions which, although they can last for weeks are really only an explosion of short duration, following by consequential events like mud or lava flows which can last weeks. However, far away (and long ago by the time we find out), there are explosions which are on such a scale they can take months. There are lots of stars and sometimes, they explode. In a sense, nothing lasts forever, yet at the same time, matter is, in one form or another, eternal. Explosions are part of this process. Quite how many stars exist is unknown and given we can observe only part of the universe, any estimate beyond a certain point is meaningless although, given calculations based on observable data suggest that there are at hundreds of billions of galaxies, each of which probably contains millions or billions of stars. So, estimates (guesses) vary but the fact 1 septillion (1 followed by 24 zeros) is thought credible is interesting, not for the specific value it represents but because it means whatever might be the answer, it’s a very big number. The time it takes for a star to explode depends on the type of star and the point it’s reached in its evolution but the two most significant types of stellar explosions are (1) supernovae and (2) stellar novae. The mechanics and time absorbed by each in their explosions varies greatly.
A supernova is a powerful and catastrophic
explosion which occurs at the end of the life of a massive star (or in a binary
star system) and it can take (as seen from Earth) from a few weeks to several
months. As a prelude, over millions of
years, the star will undergoes various stages of nuclear burning and fusion, culminating
eventually in a catastrophic collapse and explosion. Less energetic is a stellar novae which occurs
in binary systems where a white dwarf star accretes matter from its companion
star. The accumulation of matter on the
surface of the dwarf can lead to a sudden and rapid release of energy,
resulting in a nova explosion. Novae
typically brighten over a short period, reaching peak brightness in a matter of
days or weeks, after which they gradually fade away over several months. Not all stars end with an explosion. Less massive bodies (like our Sun) don’t
explode but kind of fade away through a process cosmologists call stellar
evolution, expanding into red giants, shedding their outer layers, eventually to
be become white dwarfs on the path to dark, dead obscurity. Back on Earth, the figurative use extends
from a rapid increase in popularity of someone or something to sudden outbreaks
of violence by individuals or entire societies and something said or done which
might induce either of the latter can be said to be “potentially explosive”.
Conversely, “implosion” is used figuratively to describe an internal collapse or inward sinking, rather than an outward burst although the latter may be consequent upon the former. It’s suggestive of a situation or event where there is (suddenly or gradually) failure, disintegration, or decline, typically accompanied by a loss of control or power and implosions are often associated with the gradual accumulation of pressures or internal forces that eventually lead to a collapse or breakdown. Individuals, institutions or societies may be said to have imploded because they lacked the strength, internal cohesion or resources to resist pressures which may be externally imposed, generated internally or a combination of both. However, although both explosion and (probably more frequently) implosion are among the general population commonly used terms when discussing aspects of metal health (usually of others), they’re officially not part of the lexicon of clinicians or other professionals in the field. It may be that the words are sometimes in their thoughts when faming a diagnosis but neither appears in the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM) which for decades has provided a standardized classification and criteria for diagnosing mental disorders.
An explosion: A simulation of the detonation of the Soviet Union’s AN602 Царь-бо́мба (Tsar Bomba), a thermonuclear gravity bomb which was the most powerful nuclear weapon yet built (as far as is known) or tested. It was detonated on 30 October 1961 on a remote island in the Barents sea and the Russian claim of a yield equivalent to 50 megatons of TNT is now generally accepted (the contemporary US estimate of 57-60 was based on more remote observations).
No comments:
Post a Comment