SUMMARY / RELATED TOPICS

Theory of justification

The theory of justification is a part of epistemology that attempts to understand the justification of propositions and beliefs. Epistemologists are concerned with various epistemic features of belief, which include the ideas of justification, warrant and probability. Loosely speaking, justification is the reason; when a claim is in doubt, justification can be used to support the claim and reduce or remove the doubt. Justification can use authoritative testimony, or reason. Justification focuses on beliefs; this is in part because of the influence of the definition of knowledge as "justified true belief" associated with a theory discussed near the end of the Plato's dialogues Meno and Theaetetus. More theories of justification focus on the justification of statements or propositions; the subject of justification has played a major role in the value of knowledge as "justified true belief". Some contemporary epistemologists, such as Jonathan Kvanvig assert that justification isn't necessary in getting to the truth and avoiding errors.

Kvanvig attempts to show that knowledge is no more valuable than true belief, in the process dismissed the necessity of justification due to justification not being connected to the truth. Justification is the reason why someone properly holds a belief, the explanation as to why the belief is a true one, or an account of how one knows what one knows. In much the same way arguments and explanations may be confused with each other, so may explanations and justifications. Statements that are justifications of some action take the form of arguments. For example, attempts to justify a theft explain the motives, it is important to be aware. A criminal profiler may offer an explanation of a suspect's behavior, such statements may help us understand why the person committed the crime. An uncritical listener may believe the speaker is trying to gain sympathy for the person and his or her actions, but it does not follow that a person proposing an explanation has any sympathy for the views or actions being explained.

This is an important distinction because we need to be able to understand and explain terrible events and behavior in attempting to discourage it. There are several different views as to what entails justification focusing on the question "How sure do we need to be that our beliefs correspond to the actual world?" Different theories of justification require different amounts and types of evidence before a belief can be considered justified. Theories of justification include other aspects of epistemology, such as knowledge. Popular theories of justification include: Epistemic coherentism – Beliefs are justified if they cohere with other beliefs a person holds, each belief is justified if it coheres with the overall system of beliefs. Externalism – Outside sources of knowledge can be used to justify a belief. Foundationalism – Basic beliefs justify other, non-basic beliefs. Foundherentism – A combination of foundationalism and epistemic coherentism, proposed by Susan Haack Infinitism – Beliefs are justified by infinite chains of reasons.

Internalism – The believer must be able to justify a belief through internal knowledge. Reformed epistemology – Beliefs are warranted by proper cognitive function, proposed by Alvin Plantinga. Skepticism – A variety of viewpoints questioning the possibility of knowledge truth skepticism – Questions the possibility of true knowledge, but not of justified knowledge epistemological skepticism – Questions the possibility of justified knowledge, but not true knowledge Evidentialism – Beliefs depend on the evidence for them. If a belief is justified, there is something that justifies it, which can be called its "justifier". Common examples include: Abductive reasoning A priori knowledge Argument Autonomy and freedom of choice Axiom or Postulate Coherence Command and control, subordination in a hierarchy Common sense Conformity Conscience Consequence Cost–benefit analysis Deduction Dialectic Socratic method Marxist dialectic Hegelian dialectic Dogma Duty and Deontological ethics Empiricism Enlightenment Evidence Fatalism Group decision-making Groupthink Hedonism Induction Intuition Law Law of nature Logical positivism Mathematical proof Occam's Razor Pragmatism Probability theory Rationalism Reason Revelation Divination Divine illumination Scientific demonstration Scientific method Self-interest Taboo Tradition Utility Will to power The major opposition against the theory of justification is non-justificational criticism, most notably held by some of the proponents of critical rationalism: W. W. Bartley, David Miller and Karl Popper.

In justificationism, criticism consists of trying to show that a claim cannot be reduced to the authority or criteria that it appeals to. That is, it regards the justification of a claim as primary, while the claim itself is secondary. By contrast, non-justificational criticism works towards attacking claims themselves. Bartley refers to a third position, which he calls critical rationalism in a more specific sense, claimed to have been Popper's view in his Open Society, it has given up justification, but not yet adopted non-justificational criticism. Instead of appealing to criteria and authorities, it attempts to explicate them. Fogelin claims to detect a suspicious resemblance between the Theories of Jus

General Electric T58

The General Electric T58 is an American turboshaft engine developed for helicopter use. First run in 1955, it remained in production until 1984, by which time some 6,300 units had been built. On July 1, 1959, it became the first turbine engine to gain FAA certification for civil helicopter use; the engine was license-built and further developed by de Havilland in the UK as the Gnome, in the West Germany by Klöckner-Humboldt-Deutz, manufactured by Alfa Romeo and the IHI Corporation. Development commenced with a 1953 US Navy requirement for a helicopter turboshaft to weigh under 400 lb while delivering 800 hp; the engine General Electric built weighed only 250 lb and delivered 1,050 hp and was soon ordered into production. First flight was on a modified Sikorsky HSS-1 in 1957, civil certification for the CT58-100 variant was obtained two years later. A number of unusual features are incorporated into the T58:1) an all-axial compressor. Most other turboshafts in this power bracket have a centrifugal unit as a final compressor stage.

As a result, the blades at the rear of the compressor are small and thin. 2) compressor handling at part speed is facilitated by several rows of variable stators at the front part of the unit. This was a novel feature when the engine was first introduced. 3) a single stage power turbine. Which delivers power to the rear of engine; the hot exhaust stream is diverted sideways, away from the output shaft, by a skewed jet pipe.4) the combustor is a straight-through annular design, rather than reverse flow. The main production version of the engine was the T58-GE-10; the most powerful version, the T58-GE-16, produces 1,870 hp. T58-GE-1 1,290 hp T58-GE-2 1,325 hp T58-GE-3 1,290 hp T58-GE-4 T58-GE-5 1,500 hp T58-GE-6 1,250 hp T58-GE-8B 1,250 hp T58-GE-8E 1,350 hp T58-GE-8F 1,350 hp T58-GE-10 1,400 hp T58-GE-14 1,400 hp 2-stage power turbine T58-GE-16 1,870 hp T58-GE-100 1,500 hp T58-GE-402 1,500 hp CT58-100-1 1,050 hp CT58-110-1 1,350 hp CT58-140-1 1,500 hp commercial T58-GE-10 Ishikawajima-Harima CT58-IHI-110-1 1,400 hp Ishikawajima-Harima CT58-IHI-140-1 1,400 hp Ishikawajima-Harima T58-IHI-8B BLC For Shin Meiwa PS-1 BLC system Rolls-Royce Gnome Licensed production and development of the T58 in the United Kingdom.

Two T58s, converted to turbojets by the removal of the power turbines, were used as the engines on the Maverick TwinJet 1200. The Carroll Shelby turbine cars entered; the cars were found to be using variable inlets to get around the USAC regulations on the maximum allowable inlet size and were disqualified. Turboshaft engines like the GE T58, Lycoming T53/T55 are used to power high performance powerboats, such as aport and offshore vee, catamaran hulls like the Skater "Jet Set" or Mystic Powerboats "My Way", water jet river racers like Unnatural Disaster and hydroplanes; some of these boats run despite them being open cockpit pleasure boats. There is a YT58-GE-2A cutaway on display at the New England Air Museum, Bradley International Airport, Windsor Locks, CT Data from Type: Free power turboshaft Length: 55 in Diameter: 16 in Dry weight: 285 lb without reduction gearbox, 391 lb with reduction gearbox Compressor: 10 stage axial-flow compressor with variable inlet guide vanes + variable incidence stators in first three stages Combustors: Annular combustion chamber with 16 burner nozzles on two manifolds Turbine: 2x gas generator turbine stages+ 1x free power turbine stage Fuel type: Aviation kerosene Maximum power output: 1,250 hp Overall pressure ratio: 8.3:1 Air mass flow: 12.4 lb/s at 26,300 rpm Specific fuel consumption: 0.64 lb/hp/h at maximum continuous rating Power-to-weight ratio: 6.1 hp/lb without reduction gearbox Related development Rolls-Royce Gnome Related lists List of aircraft engines Gunston, Bill.

World Encyclopedia of Aero Engines. Wellingborough: Patrick Stephens. P. 65. GE Aviation T58 page and T58 history page Minijets website

USS Theodore Roosevelt (SSBN-600)

USS Theodore Roosevelt, a George Washington-class submarine, was the second ship of the United States Navy to be named for President Theodore Roosevelt. Unnamed and assigned hull classification symbol SSGN-600 as a guided missile submarine, her keel was laid down on 20 May 1958 by the Mare Island Naval Shipyard using components assembled for the Skipjack-class submarine nuclear attack submarine USS Scamp, she was named Theodore Roosevelt and redesignated fleet ballistic missile submarine SSBN-600 on 6 November 1958, launched on 3 October 1959 sponsored by Mrs. Alice Roosevelt Longworth, daughter of the ship's namesake, commissioned on 13 February 1961 with Commander William E. Sims commanding the Blue Crew and Commander Oliver H. Perry, Jr. commanding the Gold Crew. On 18 February 1961, Theodore Roosevelt departed Mare Island, bound for the United States East Coast. On 7 March, she became the first FBM submarine to transit the Panama Canal. On 11 March 1961, she arrived at Florida. After firing her first Polaris A1 missile on 20 March 1961 and completing her shakedown training, she arrived in Groton, Connecticut, on 1 May for post-shakedown repairs at the Electric Boat Company shipyard.

She completed those repairs on 24 June 1961 and departed Groton, bound for Charleston, South Carolina. Theodore Roosevelt stopped at Norfolk, along the way and arrived at Charleston on 7 July 1961. Between 7 July and 19 July 1961, she loaded Polaris missiles at the Naval Ammunition Depot and made all other preparations for her first deployment. On 19 July 1961, she stood out of Charleston on her first deterrent patrol, she concluded that patrol on 23 September 1961 at the FBM submarine base at Scotland. Over the next three and one-half years, Theodore Roosevelt made 15 more deterrent patrols from the Holy Loch. Late in the spring of 1965, she departed Holy Loch on her 17th and final patrol of the deployment to Holy Loch, she concluded that patrol and the deployment when she arrived in Charleston on 15 June 1965. She unloaded her 16 Polaris missiles and departed Charleston for New London, where she arrived on 26 June 1965. At New London, Theodore Roosevelt entered the shipyard of the Electric Boat Division for an extensive overhaul.

Between July 1965 and January 1967, her nuclear reactor was refueled and her Polaris weapon system was modified to accept the more advanced Polaris A3 missile. She completed overhaul on 14 January 1967 and began sea trials and refresher training, all of which culminated in the successful firing of a Polaris A3 missile at the Cape Canaveral missile range late in April 1967. At the end of the training period, she returned to Charleston to load missiles and to prepare for another series of deterrent patrols out of Holy Loch, she completed that cruise at the Holy Loch base. Theodore Roosevelt's second tour of duty operating from the Scotland base proved to be brief in comparison to her first. Between mid-June 1967 and February 1968, she completed her 18th through 21st patrols. On 20 March 1968 while returning to Holy Loch from her 21st patrol, she ran aground off the western coast of Scotland. After drydocking for temporary correction of the damage, she departed Holy Loch on 5 April 1968 to return to the United States for permanent repairs.

Between 18 April and 20 April 1968 she unloaded her missiles at Charleston and headed north to New London. On 23 April 1968, she arrived in the shipyard of the Electric Boat Division and commenced an extended repair period. Labor disputes caused delays, Theodore Roosevelt did not complete her repairs until mid-October 1968, she spent the latter part of that month in sea trials and departed New London on 2 November 1968 on her post-repair shakedown cruise. She visited Norfolk, Puerto Rico, St. Croix in the United States Virgin Islands before concluding the cruise at Charleston on 27 November 1968, she conducted training operations out of Charleston before deploying to Holy Loch again early in 1969. That tour of duty lasted until May 1971. During the interim, Theodore Roosevelt conducted nine more deterrent patrols, returning to Holy Loch for refit after each. On 12 May 1971, she stood out of Holy Loch on the 31st patrol of her career. On 20 July 1971, she arrived in New London completing both the Holy Loch deployment.

She remained in New London for three weeks, during which time members of her Blue crew and her Gold crew were brought together into a single overhaul crew while other members of both crews moved on to other assignments. On 10 August 1971, she headed south to Charleston where she arrived on 13 August 1971. Over the next month, she underwent refit and departed Charleston on 11 September 1971 for special operations. Theodore Roosevelt returned to Charleston on 30 September 1971 and remained there a week and a day before returning to sea for another three weeks of special operations, she began preoverhaul restricted repairs. Three weeks she began her refueling overhaul, which lasted for more than two years. Theodore Roosevelt completed her overhaul in January 1974. During the following two months, she conducted sea trials out of Charleston. In April and May shakedown training and nuclear weapons certification preparations occupied her time. In June, she conducted a one-week United States Naval Academy midshipman familiarization cruise out of New London underwent nuclear propulsion safety training before deperming at Norfolk.

In mid-June, she received word of her reassignment to the United States Pacific Fleet with her new home port to be Pearl Harbor, Hawaii. Between July and September 1974, Theodore Roosevel