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Software transactional memory

In computer science, software transactional memory (STM) is a concurrency control mechanism analogous to database transactions for controlling access to shared memory in concurrent computing. It is an alternative to lock-based synchronization. STM is a strategy implemented in software, rather than as a hardware component. A transaction in this context occurs when a piece of code executes a series of reads and writes to shared memory. These reads and writes logically occur at a single instant in time; intermediate states are not visible to other (successful) transactions. The idea of providing hardware support for transactions originated in a 1986 paper by Tom Knight. The idea was popularized by Maurice Herlihy and J. Eliot B. Moss. In 1995, Nir Shavit and Dan Touitou extended this idea to software-only transactional memory (STM). Since 2005, STM has been the focus of intense research and support for practical implementations is growing.

Performance
Unlike the locking techniques used in most modern multithreaded applications, STM is often very optimistic: a thread completes modifications to shared memory without regard for what other threads might be doing, recording every read and write that it is performing in a log. Instead of placing the onus on the writer to make sure it does not adversely affect other operations in progress, it is placed on the reader, who after completing an entire transaction verifies that other threads have not concurrently made changes to memory that it accessed in the past. This final operation, in which the changes of a transaction are validated and, if validation is successful, made permanent, is called a commit. A transaction may also abort at any time, causing all of its prior changes to be rolled back or undone. If a transaction cannot be committed due to conflicting changes, it is typically aborted and re-executed from the beginning until it succeeds.

The benefit of this optimistic approach is increased concurrency: no thread needs to wait for access to a resource, and different threads can safely and simultaneously modify disjoint parts of a data structure that would normally be protected under the same lock.

However, in practice, STM systems also suffer a performance hit compared to fine-grained lock-based systems on small numbers of processors (1 to 4 depending on the application). This is due primarily to the overhead associated with maintaining the log and the time spent committing transactions. Even in this case performance is typically no worse than twice as slow. Advocates of STM believe this penalty is justified by the conceptual benefits of STM.

Theoretically, the worst case space and time complexity of n concurrent transactions is O(n). Actual needs depend on implementation details (one can make transactions fail early enough to avoid overhead), but there will also be cases, albeit rare, where lock-based algorithms have better time complexity than software transactional memory.

Conceptual advantages and disadvantages
In addition to their performance benefits, STM greatly simplifies conceptual understanding of multithreaded programs and helps make programs more maintainable by working in harmony with existing high-level abstractions such as objects and modules. Lock-based programming has a number of well-known problems that frequently arise in practice:

 * Locking requires thinking about overlapping operations and partial operations in distantly separated and seemingly unrelated sections of code, a task which is very difficult and error-prone.
 * Locking requires programmers to adopt a locking policy to prevent deadlock, livelock, and other failures to make progress. Such policies are often informally enforced and fallible, and when these issues arise they are insidiously difficult to reproduce and debug.
 * Locking can lead to priority inversion, a phenomenon where a high-priority thread is forced to wait for a low-priority thread holding exclusive access to a resource that it needs.

In contrast, the concept of a memory transaction is much simpler, because each transaction can be viewed in isolation as a single- threaded computation. Deadlock and livelock are either prevented entirely or handled by an external transaction manager; the programmer need hardly worry about it. Priority inversion can still be an issue, but high-priority transactions can abort conflicting lower priority transactions that have not already committed.

However, the need to retry and abort transactions limits their behavior. Any operation performed within a transaction must be idempotent since a transaction might be retried. Additionally, if an operation has side effects that must be undone if the transaction is aborted, then a corresponding rollback operation must be included. This makes many input/output (I/O) operations difficult or impossible to perform within transactions. Such limits are typically overcome in practice by creating buffers that queue up the irreversible operations and perform them after the transaction succeeds. In Haskell, this limit is enforced at compile time by the data type system.

Composable operations
In 2005, Tim Harris, Simon Marlow, Simon Peyton Jones, and Maurice Herlihy described an STM system built on Concurrent Haskell that enables arbitrary atomic operations to be composed into larger atomic operations, a useful concept impossible with lock-based programming. To quote the authors:

Perhaps the most fundamental objection [...] is that lock-based programs do not compose: correct fragments may fail when combined. For example, consider a hash table with thread-safe insert and delete operations. Now suppose that we want to delete one item A from table t1, and insert it into table t2; but the intermediate state (in which neither table contains the item) must not be visible to other threads. Unless the implementor of the hash table anticipates this need, there is simply no way to satisfy this requirement. [...] In short, operations that are individually correct (insert, delete) cannot be composed into larger correct operations. —Tim Harris et al., "Composable Memory Transactions", Section 2: Background, pg.2

With STM, this problem is simple to solve: simply wrapping two operations in a transaction makes the combined operation atomic. The only sticking point is that it is unclear to the caller, who is unaware of the implementation details of the component methods, when it should attempt to re-execute the transaction if it fails. In response, the authors proposed a  command which uses the transaction log generated by the failed transaction to determine which memory cells it read, and automatically retries the transaction when one of these cells is modified, based on the logic that the transaction will not behave differently until at least one such value is changed.

The authors also proposed a mechanism for composition of alternatives, the  function. It runs one transaction and, if that transaction does a retry, runs a second one. If both retry, it tries them both again as soon as a relevant change is made. This facility, comparable to features such as the Portable Operating System Interface (POSIX) networking  call, allows the caller to wait on any one of a number of events simultaneously. It also simplifies programming interfaces, for example by providing a simple mechanism to convert between blocking and nonblocking operations.

This scheme has been implemented in the Glasgow Haskell Compiler.

Proposed language support
The conceptual simplicity of STMs enables them to be exposed to the programmer using relatively simple language syntax. Tim Harris and Keir Fraser's "Language Support for Lightweight Transactions" proposed the idea of using the classical conditional critical region (CCR) to represent transactions. In its simplest form, this is just an "atomic block", a block of code which logically occurs at a single instant:

// Insert a node into a doubly linked list atomically atomic { newNode->prev = node; newNode->next = node->next; node->next->prev = newNode; node->next = newNode; }

When the end of the block is reached, the transaction is committed if possible, or else aborted and retried. (This is simply a conceptual example, not correct code. For example, it behaves incorrectly if node is deleted from the list during the transaction.)

CCRs also permit a guard condition, which enables a transaction to wait until it has work to do:

atomic (queueSize > 0) { remove item from queue and use it }

If the condition is not satisfied, the transaction manager will wait until another transaction has made a commit that affects the condition before retrying. This loose coupling between producers and consumers enhances modularity compared to explicit signaling between threads. "Composable Memory Transactions" took this a step farther with its retry command (discussed above), which can, at any time, abort the transaction and wait until some value previously read by the transaction is modified before retrying. For example:

atomic { if (queueSize > 0) { remove item from queue and use it     } else { retry } }

This ability to retry dynamically late in the transaction simplifies the programming model and opens up new possibilities.

One issue is how exceptions behave when they propagate outside of transactions. In "Composable Memory Transactions", the authors decided that this should abort the transaction, since exceptions normally indicate unexpected errors in Concurrent Haskell, but that the exception could retain information allocated by and read during the transaction for diagnostic purposes. They stress that other design decisions may be reasonable in other settings.

Transactional locking
STM can be implemented as a lock-free algorithm or it can use locking. There are two types of locking schemes: In encounter-time locking (Ennals, Saha, and Harris), memory writes are done by first temporarily acquiring a lock for a given location, writing the value directly, and logging it in the undo log. Commit-time locking locks memory locations only during the commit phase.

A commit-time scheme named "Transactional Locking II" implemented by Dice, Shalev, and Shavit uses a global version clock. Every transaction starts by reading the current value of the clock and storing it as the read-version. Then, on every read or write, the version of the particular memory location is compared to the read-version; and, if it is greater, the transaction is aborted. This guarantees that the code is executed on a consistent snapshot of memory. During commit, all write locations are locked, and version numbers of all read and write locations are re-checked. Finally, the global version clock is incremented, new write values from the log are written back to memory and stamped with the new clock version.

Implementation issues
One problem with implementing software transactional memory with optimistic reading is that it is possible for an incomplete transaction to read inconsistent state (that is, to read a mixture of old and new values written by another transaction). Such a transaction is doomed to abort if it ever tries to commit, so this does not violate the consistency condition enforced by the transactional system, but it is possible for this "temporary" inconsistent state to cause a transaction to trigger a fatal exceptional condition such as a segmentation fault or even enter an endless loop, as in the following contrived example from Figure 4 of "Language Support for Lightweight Transactions":

Provided x=y initially, neither transaction above alters this invariant, but it is possible that transaction A will read x after transaction B updates it but read y before transaction B updates it, causing it to enter an infinite loop. The usual strategy for dealing with this is to intercept any fatal exceptions and abort any transaction that is not valid.

One way to deal with these issues is to detect transactions that execute illegal operations or fail to terminate and abort them cleanly; another approach is the transactional locking scheme.

Practical implementations

 * Haskell GHC
 * C++ cpp_stm_free
 * Clojure Refs, ported to node-stm
 * Go Kashmir
 * Rust async-stm
 * Scala ZIO
 * OCaml Kcas

title: Software transactional memory


text:
Talk:Milpa

Untitled
Is this a form of crop rotation? --Ant 22:36, 7 Feb 2005 (UTC)
 * Not necessarily, it is not a farming system, the campesinos, see their milpa as an ecosystem. Usually there is no separation of plants. Beans provide nitrogen to soil, but maiz grows near beans. They handle it wisely with their empirical knowledge, which may be disguised in a some animistic and religious discourse in some regions. It is not restricted to the Mayan area, the word comes from Nahuatl from a culture around the center of Mexico. Some things considered plagues, are not in the milpa vision, for example the huitlacoche is a mushroom that grows in maiz, it is exquisite, they also produce edible insects, like some kinds of ants, chapulines (a kind of cricket), which are tasty. The milpa is a very productive system, it's strength is it's biodiversity, that makes it more resistant to environmental changes. Crop rotation, is different, if I remember well my primary school, it consist in one period crop beans, the next maiz, alternating the different products maintain the soil fertile. Although that is not the main strategy in developing a milpa, I believe that it could be adopted in some cases if the system demands it. The campesinos, adapt to their specific needs.
 * Kind of. It is a cultural system for honoring nature. It is an agricultural system based on religion originated by the Maya of Central America thousands of years ago. —The preceding unsigned comment was added by 24.21.85.44 (talk • contribs) 28 November 2006.

 * Don't know about it being a system to 'honor nature'- it was an eminently practical method whose main aim of producing food for the people far outweighed any activity done on the fields for purely religious purposes.--cjllw | TALK  01:50, 28 November 2006 (UTC)

 * As I understand it, it's not "purely religious" or "purely practical" - traditional Mesoamerican culture doesn't really have a secular/religious distinction. It's an effective agricultural system closely tied to many cultural and religious practices and meanings. Nagopaleen (talk) 00:09, 27 February 2011 (UTC)

17°56'39.38"N  90°10'7.18"W
Heard a lot in the news lately about a kid claiming he used sattelite imagery plus some astronomical calculations and found a possible mayan pyramid. Academics seem to dismiss it as just likely being a Milpa or marijuana field. Coordinates in title, any thoughts?

66.222.176.75 (talk) 21:03, 11 May 2016 (UTC)

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

title: Talk:Milpa


text:
NBA TV Canada

NBA TV Canada is a Canadian English language discretionary specialty channel owned by Maple Leaf Sports & Entertainment (MLSE). It is the Canadian version of NBA TV, broadcasting programming focused on the National Basketball Association, and its Canadian franchise, the Toronto Raptors.

History
In December 2000, MLSE was granted approval by the Canadian Radio-television and Telecommunications Commission (CRTC) for a Category 2 digital specialty channel licence tentatively known as Raptors Basketball Channel, a channel described as being devoted primarily to the Toronto Raptors basketball franchise and the National Basketball Association (NBA), with additional programming related to other aspects of basketball.

With the launch of other Canadian channels, the channel was launched on 7 September 2001, as Raptors NBA TV, with programming focused on the NBA and other basketball-related programming, although it maintained a particular emphasis on the Toronto Raptors. On 1 November 2005, the high-definition version of this channel, named NBA TV Canada HD, was launched, originally named Raptors NBA TV HD.

On 15 October 2010, the channel was renamed as NBA TV Canada, being the current and second name of the channel, as the channel began to air more programming devoted to the NBA and international basketball in general, sourced from its American counterpart.

The channel was valued at $21 million on behalf of the CRTC in mid-2012.

Programming
NBA TV Canada broadcasts programming primarily related to the NBA and the Raptors, as well as coverage of other leagues including the NBA G League, Summer League, and the Women's National Basketball Association (WNBA). Regular hosts for local studio programming include David Amber, Sherman Hamilton, Matt Devlin, Leo Rautins and Jack Armstrong. The channel broadcasts NBA games sourced from NBA TV and ESPN, and NBA TV series and studio programs.

NBA TV Canada does not broadcast live Raptors games outside of the pre-season (which are split between the networks of TSN and Sportsnet—which are owned by the co-majority owners of MLSE, Rogers Communications and Bell Canada), but does broadcast full and abbreviated encores of Raptors telecasts.

title: NBA TV Canada


text: Category:High schools in Alaska

title: Category:High schools in Alaska


text:
VII Corps (United Kingdom)

VII Corps was an army corps of the British Army active in the First and Second World Wars. In the early part of the Second World War it was part of the defence forces of the United Kingdom, and later acted as a shadow formation for deception purposes.

Prior to the First World War
In 1876 a Mobilisation Scheme was published for the forces in Great Britain and Ireland, including eight army corps of the 'Active Army'. The '7th Corps' was to be headquartered at York, formed from Irish and English militia. In 1880 its order of battle was as follows:
 * 1st Division (York)
 * 1st Brigade (York)
 * 5th West York Militia (Knaresborough), 6th West York Militia (Halifax), Leicester Militia (Leicester)
 * 2nd Brigade (York)
 * North Down Militia (Newtownards), South Down Militia (Downpatrick), Dublin County Militia (Dublin)
 * Divisional Troops
 * 106th Foot (Preston), Yorkshire Yeomanry (York)
 * Artillery
 * N/2nd Brigade Royal Artillery (Coventry)
 * 2nd Division (Northampton)
 * 1st Brigade (Northampton)
 * Northampton and Rutland Militia (Northampton), 1st Norfolk Militia (Norwich), 2nd Norfolk Militia (Yarmouth)
 * 2nd Brigade (Northampton)
 * Cambridge Militia (Ely), West Suffolk Militia (Bury St Edmunds), West Essex Militia (Chelmsford)
 * Divisional Troops
 * 76th Foot (Sheffield), Southern Nottinghamshire Yeomanry (Nottingham), Nottinghamshire Yeomanry (Worksop)
 * 3rd Division (Darlington)
 * 1st Brigade (Darlington)
 * North Lincoln Militia (Lincoln), South Lincoln Militia (Grantham), Nottingham Militia (Newark)
 * 2nd Brigade (Newcastle)
 * Hertford Militia (Hertford), Bedford Militia (Bedford), Huntingdon Militia (Huntingdon)
 * Divisional Troops
 * 36th Foot (Fleetwood), 2nd West York Yeomanry (Halifax)
 * Cavalry Brigade (Doncaster)
 * 6th Dragoons (Edinburgh), 21st Hussars (Leeds), 4th Dragoon Guards (York), 1st West York Yeomanry (Doncaster)

This scheme had been dropped by 1881.

First World War
VII Corps formed in France on 14 July 1915 under the command of Lt-General Thomas D'Oyly Snow (previously commander of 27th Division) as part of Sir Charles Monro's Third Army on the Western Front.

Order of Battle of VII Corps 14 July 1915 General Officer Commanding (GOC): Lt-Gen Sir Thomas D'O. Snow
 * 4th Division
 * 37th Division
 * 48th (South Midland) Division

1916
In 1916 VII Corps remained in Third Army, now commanded by Sir Edmund Allenby. The Corps' first serious action was in the Somme Offensive of 1916, on the first day of which it carried out a disastrous diversionary attack at Gommecourt, in which 46th Division suffered 2455 casualties, and 56th Division 4313, for no permanent gain.

Order of Battle of VII Corps 1 July 1916 GOC: Lt-Gen Sir Thomas D'O. Snow GOC, Royal Artillery: Brig-Gen C.M. Ross-Johnson GOC, Heavy Artillery: Brig-Gen C.R. Buckle Chief Engineer: Brig-Gen J.A. Tanner
 * 46th (North Midland) Division
 * 56th (1/1st London) Division
 * 37th Division (in reserve)

From 10 May 1916 to 16 July 1917, 1st North Irish Horse constituted VII Corps Cavalry Regiment.

1917
When the German Army retreated to the Hindenburg Line in March 1917, VII Corps was the only part of Third Army required to follow up, south of the new line's pivot at Vimy Ridge.

Order of Battle of VII Corps 14 March-5 April 1917
 * 14th (Light) Division
 * 21st Division
 * 39th Division
 * 56th (1/1st London) Division

During the Arras Offensive of April and May 1917, VII Corps was engaged in all three Battles of the Scarpe. During the First Battle of the Scarpe, 9–14 April, it had the same divisions under command, with the addition of 50th (Northumbrian) Division, which captured the Wancourt Ridge. VII Corps then had 30th, 50th and 33rd Division engaged in the Second Battle of the Scarpe, 23–24 April. During the Third Battle of the Scarpe, 3–4 May, it operated with 14th (Light), 14th (Eastern) and 21st Divisions. Finally, for the subsequent actions on the Hindenburg Line, 20 May-16 June, VII Corps had 21st and 33rd Divisions under command.

Later in 1917 the corps fought in the Battle of Cambrai.

1918
In 1918 the command was taken over by Lt-Gen Sir Walter Congreve, VC, KCB, MVO. and the corps fought during Operation Michael and the subsequent victorious British advance of the Hundred Days Offensive that ended the war.

Order of Battle of VII Corps 21 March-23 March 1918

9th Division 16th Division 21st Division 39th Division

Order of Battle of VII Corps 24 March-26 March 1918

9th Division 16th Division 21st Division 35th Division 39th Division 1st Cavalry Division

Order of Battle of VII Corps 27 March-29 March 1918

9th Division 21st Division 35th Division 1st Cavalry Division

Order of Battle of VII Corps 28 March-5 April 1918

9th Division 21st Division 35th Division 1st Cavalry Division 4th Australian Division

Second World War
VII Corps was reformed in the United Kingdom during mid-1940 to control field forces deployed to counter the German invasion threat of that year. On 17 July that year it comprised 1st Canadian Infantry Division, 1st Armoured Division, and 2nd New Zealand Expeditionary Force (UK), a somewhat oversized brigade based on the second NZ echelon of troops (of the 2nd New Zealand Expeditionary Force) which had been diverted to the United Kingdom from Egypt. The Corps was placed under the command of Lieutenant-General Andrew McNaughton, a Canadian Army officer. At the time its allotted task was to 'counter-attack and destroy any enemy force invading the counties of Surrey, Kent, Sussex and Hampshire which was not destroyed by the troops of the Eastern and Southern Commands'.

The Official History of New Zealand in the Second World War 1939–45 writes: The rest of the echelon spent their time training for their role in the defence of Britain. General Freyberg had given the officers an inspiring survey of the military situation; the press and Mr Churchill warned everyone that each weekend was a potential crisis. And history seemed to be repeating itself with some romantic variations. On 6 July the battalions were inspected by King George VI, and men with imagination and some slight knowledge of history thought of Elizabeth I at Tilbury or of George III reviewing his regiments when they were waiting for the forces of Napoleon.

At this stage the battalions and detachments of reinforcements with the Second Echelon had been organised into 2 NZEF (UK), with a Force Headquarters and three groups. Headquarters Covering Force (Brigadier Miles) had C Squadron of the Divisional Cavalry Regiment, a machine-gun company and an infantry battalion commanded by Lieutenant-Colonel Fraser and made up of the men from the two batteries of 5 Field Regiment and the two batteries of 7 Anti-Tank Regiment that were still without guns. The Mixed Brigade (Brigadier Barrowclough) was formed from 28 (Maori) Battalion and 29 (or Composite) Battalion (Lieutenant-Colonel McNaught) organised from the unattached infantry reinforcements. The third group was 5 Infantry Brigade (Brigadier Hargest). Fourth Anti-Tank Company was attached to the Mixed Infantry Brigade and 5 Anti-Tank Company to 5 Infantry Brigade.

There was still an acute shortage of arms, vehicles and equipment. Fifth Field Regiment had only one battery: a collection of 18-pounder guns and 4.5 in howitzers. The anti-tank companies had been given the Bedford 30-cwt trucks, sheeted with 5/8 in steel plate and equipped with Bren guns and anti-tank rifles. C Squadron Divisional Cavalry had six light tanks and six Bren carriers. The Army Service Corps details, men from the Petrol and Ammunition Companies, had motor lorries, but for the transportation of troops 8 and 9 Motor Coach Companies had been attached from the Royal Army Service Corps. With their enormous camouflaged buses they could lift the whole force in one move.

On 25 December 1940 VII Corps was renamed the Canadian Corps at a time when the threat of German invasion had somewhat dissipated and as the growing number of Canadian troops in the United Kingdom made the formation of a larger Canadian formation advisable. It was based at Headley Court in Surrey.

Later in the war it was notionally reactivated for deception purposes as a formation of the British Fourth Army as part of Operation Fortitude North, the threat to invade Norway at the time of the Normandy landings, with headquarters at Dundee. It was composed of the genuine British 52nd Infantry Division at Dundee, the notional U.S. 55th Division in Iceland, a Norwegian brigade, and three notional U.S. Army Ranger battalions in Iceland, plus corps troops. It moved south with Fourth Army for Fortitude South II, the continuation of the threat to the Pas de Calais, with headquarters at Folkestone in Kent and consisting of the British 61st and 80th divisions and 5th Armoured Division, the latter two notional and the 61st a genuine but low-establishment formation. It notionally moved to East Anglia in September, to Yorkshire in December, and was notionally disbanded in January 1945. Its insignia was a scallop shell on a blue ground.

General Officers Commanding
Commanders included:
 * 15 Jul 1915 – 3 Jan 1918 Lieutenant-General Sir Thomas Snow
 * 3 Jan – 13 Apr 1918 Lieutenant-General Sir Walter Congreve
 * 13 Apr – 19 Jun 1918 Major-General Sir Robert Whigham
 * Jul–Dec 1940 Lieutenant-General Andrew McNaughton

title: VII Corps (United Kingdom)


text:
Talk:Sikorsky S-42

The S-40 was the original Clipper. I think calling the S-42 Clipper is redundant.Bollar 22:37, Feb 7, 2005 (UTC)

There does not seem to be an entry for the S-40 yet. Since this is a unique entry I believe it would make sense to include the historic "Clipper" nicknames for the S-42.

Voila, there's now a Sikorsky S-40 page. Certainly list of all Clippers owned by PA would be cool, but I don't know how to access that without plagarising a copyrighted list. Bollar 01:40, Feb 9, 2005 (UTC)

The Sikorsky S-42 was the first real transoceanic flying boat- citation required
A source for this statement is needed. Other transoceanic flying boats include notables such as the Savoia Marchetti S.55, which had completed transatlantic flights years before the S-42.
 * The South Atlantic was crossed by a Savoia-Marchetti S.55 in 1927. A whole squadron (24) SM-55s flew the Atlantic both ways in 1933. For years afterwards "Balboa" was slang for a large formation.Mark Lincoln (talk) 21:14, 8 December 2015 (UTC)

"first real transoceanic flying boat" needs elaboration or citation. —The preceding unsigned comment was added by 76.169.110.1 (talk) 08:27, 11 April 2007 (UTC).

The S-42 was used for proving flights on both oceans. To do so it had to be stripped down and filled with fuel tanks in the fuselage. Only a token amount of mail could be carried.

Such operations were dangerous and resulted in the loss of the Samoan Clipper http://prcarc1.erau.edu/awweb/main.jsp?flag=browse&smd=2&awdid=2

The assertion that it was a transoceanic flying boat is questionable. To claim it as the first ignores the NC-4

Mark Lincoln (talk) 00:09, 8 December 2015 (UTC)

The NC-4 only made its crossing with multiple stops (and losing three of the four aircraft making the attempt), but then there is the Dornier Wal, which made the first successful crossing (non-stop) of the South Atlantic in 1926, and the Dornier X made successful crossings of the Atlantic in 1930, all with very strong credentials, and predating the S-42.NiD.29 (talk) 01:59, 8 December 2015 (UTC)
 * True, but when I spoke with him in the mid-60s Admiral Read was still proud of the flight. Both the Wal and SM 55 required stops on the way. The South Atlantic crossing by Ramón Franco required stops at Gran Canaria and Cape Verde. When passenger operations were established with the B-314 a stop in the Azores was necessary on the southern (Winter) route. The Dixie Clipper (B-314) did fly Lisbon to NYC in 1939 but the payload was zilch. Mark Lincoln (talk) 21:14, 8 December 2015 (UTC)

 * It was a major achievement, especially given the equipment available, and definitely something to be proud of.
 * Last I heard, Ireland was a part of Europe so doesn't really count as stop. The Short Empires also made the transatlantic trip, but like the S-42, were stripped down and carried extra tanks - flight reciprocity agreements between the US and the UK meant both had to have the capability so once it had been demonstrated by one, the other had to follow suit. During the war, the Empires were progressively overloaded by ever greater amounts, until just before retirement, they were carrying loads heavy enough that they could have carried passengers across the Atlantic with ease, but had been held back by overly conservative British engineering standards. Unlike the smaller Empire, the Short S.26 G class was designed for transatlantic passenger service, but was diverted to the military before it could fly - ironically, being replaced with the Boeing 314.
 * The two Empire boats used, Caledonia and Cambria were striped, had additional fuel tanks installed at the expense of payload, and still had  had to use in-flight refueling to make the trip. The tankers were converted HP Harrow bombers. Two stationed in Labrador and one in Ireland. The Cavalier which alternated with a S-42 on the NYC-Bermuda run was shipped, not flown, to Bermuda. The two surviving G-Class boats were returned to BOAC in 1941 and were used on the West Africa and Ceylon runs.Mark Lincoln (talk) 01:57, 9 December 2015 (UTC)

The S-42, in passenger configuration, was incapable of flying to Hawaii or Europe. The trans-oceanic proving flights made with the S-42 were essentially stunts. In passenger configuration, but no passengers, the S-42 had a zero fuel still air range of 2,540 miles. The trans-oceanic proving flights were made with the airplane stripped of accommodations and the fuselage filled with fuel tanks. In the serious world where money had to be made flying mail and passengers, where sufficient fuel to make an alternate destination, cope with headwinds and other weather conditions was necessary, the practical range of the S-42 was around 1,200 miles.

In his address to the Royal Aeronautical Society about the S-42 Igor Sikorsky said "The final accepted report shows the performance as: . . . Range at cruising speed, sea level 1,200 miles." He compared the S-42 to the S-40 "If equal pay loads are considered, that is, 7,500lbs., the range for the S-40 is 479 miles and in the S-42 is 1,130 miles, an increase of 651 miles."

One need only ponder the services actually flown by S-42s to grasp it's capabilities as an airliner.

Pan Am was only able to start trans-Pacific operations when it had the Martin M-130. Trans-Atlantic service was not possible until the Boeing 314 arrived.

Could a modified S-42 fly either ocean? Barely. Could it do so as a working airliner? No way.

Mark Lincoln (talk) 21:14, 8 December 2015 (UTC)

Marius Lodeesen, a Pan Am pilot who flew S-42s, wrote: "Igor Sikorsky was the first designer to try to fulfill Pan American's requirements of an aircraft that could lift enough fuel for a 2500 mile nonstop flight against a 30-mile-an-hour headwind. The result was the S-42. The airplane fell short of this requirement. Although she was used on the preliminary survey flights across the Pacific, it could only be done with the installation of cabin tanks. The S-42 performed fine service on South American costal runs and later between New York and Bermuda."

Mark Lincoln (talk) 21:46, 8 December 2015 (UTC)

aircontent
The aircontent template is somehow broken, some elements are not displayed. --87.189.121.93 (talk)

Botwood Sikorsky is not a S-42
The Sikorsky wreck at Botwood is the first VS-44 NC 41880 of the American Export Airlines which crashed on 3 October 1943.

http://aviation-safety.net/database/types/Sikorsky-VS-44/losses

http://botwood.tripod.com/aviation.html

The disposition of all S-42s is known:

S-42 NC 824M c/n 4202 Puerto Rican Clipper Crashed Port of Spain, Trinidad 11 April 1936 http://aviation-safety.net/database/record.php?id=19360411-0

S-42B Pan American Clipper, Samoan Clipper S-42B NC 16734 c/n 4207 Explosion Pago Pago, Samoa 11 January 1938 http://prcarc1.erau.edu/awweb/main.jsp?flag=browse&smd=2&awdid=2

S-42 NC 15376 c/n 4206 Dominican Clipper Crashed San Juan PR 19 February 1939 http://prcarc1.erau.edu/awweb/main.jsp?flag=browse&smd=2&awdid=1

S-42 NC 15376 c/n 4206 Crashed San Juan PR 1 3 October 1941 http://prcarc1.erau.edu/awweb/main.jsp?flag=browse&smd=2&awdid=2

NC 15376 actually had 3 accidents at San Juan The other two were:

S-42 NC 15376 c/n 4206 Crashed San Juan PR 19 February 1939 http://prcarc1.erau.edu/awweb/main.jsp?flag=browse&smd=2&awdid=1

S-42 NC 15376 c/n 4206 Crashed San Juan PR 10 March 1941 http://specialcollection.dotlibrary.dot.gov/Document?db=DOT-AIRPLANEACCIDENTS&query=(select+113

S-42 N 823M c/n 4201 West Indies Clipper, Pan American Clipper, Hong Kong Clipper Crashed Antilla, Cuba 7 August 1944 Pilot Error http://prcarc1.erau.edu/awweb/main.jsp?flag=browse&smd=2&awdid=3

S-42B NC 16736 c/n 4209 Pan American Clipper II, Bermuda Clipper Burned at dock Manus, Brazil 27 July 1943

S-42B NC 16735 c/n 4208 Bermuda Clipper, Alaska Clipper, Hong kong Clipper destroyed by Japanese Hong Kong 8 Dec. 1941

Scrapped S-42 Brazilian Clipper, Columbia Clipper NC 822M c/n 4200X scrapped 15 July 1946

S-42A Jamaica Clipper NC 15373 c/n 4203 scrapped 15 July 1946

S-42A Antilles Clipper NC 15374 c/n 4204 scrapped 15 July 1946

S-42A Brazilian Clipper NC 15375 scrapped 15 July 1946

S-42B Bermuda Clipper/Alaska Clipper/Hong Kong Clipper NC 16735 c/n 4208 scrapped 15 July 1946

Mark Lincoln (talk) 02:38, 7 December 2015 (UTC)

 * Yeah, the only citation for the claim that Botwood had an S-42 wreck was a Labrador newspaper article which was quoting a member of a local aircraft wreck recovery group. He didn't seem to know specifics of the wreck and was likely either confused or ignorant about the actual aircraft type. --Colin Douglas Howell (talk) 03:22, 7 December 2015 (UTC)
 * One S-42 did operate through Botwood on a North Atlantic proving flight.

btw, there is a second flying boat sunk off Botwood. It is a RCAF Canso (Catalina).

The S-42 was not developed from the S-40
The S-42 was not developed from the S-40. That assertion is entirely wrong. Sikorsky himself made that clear. Read his words on the matter at: http://www.sikorskyarchives.com/S-42.php The S-42 was developed because of the S-40s shortcomings.

To base an article on a single source is dubious. Especially when that source is a biography. Biographies often tend to hagiography.

The S-42 was a very important airplane for Pan Am. It replaced the Commodore on the South American and Caribbean services. It was used for trans-oceanic proving flights.

The spread of good runways across the world negated the reason for flying boats.

Basil Rowe preferred it to the S-40.

Mark Lincoln (talk) 00:47, 8 December 2015 (UTC)

For anyone interested
For a glimpse at what it was like to travel by S-42 jn the thirties try Hudson Stroude's "South by Thunderbird", Random House, 1937. There is even a S-42 on the cover.

Never mind the fact that the subject of photo #23, labeled "thunderbird rounding Sugar Loaf, Rio de Janeiro" is a Commodore. Photo #27 is a S-42.

For a pilots eye account of flying Pan Am's boats try "Captain Lodi Speaking" by Marius "Lodi" Lodeesen. Argonaut Press, Suttons Bay, Michigan, 1984. "Here is an absolutely superb book, certainly the most true-to-life and sincereaccount of a pilot's life." - Horace Brock former Chief Pilot, Pan American Airways

Lodi said that the S-42 was a notorious waterlooper. Considering the accident reports, he was right. Mark Lincoln (talk) 18:29, 8 December 2015 (UTC)

p.s. While landing at Dinner Key at the end of the S-40's maiden trip Lindbergh waterlooped it.

The Flying Boat which made the most crossings.
The Navy flew the XPB2Y from from Argentia Newfoundland to Straner, Scotland in Sept. 1941. Later USN PB2Y-3Rs were operated on trans-Atlantic service from NYC to Sandy Bay, Lough Neagh in Northern Ireland. PB2Y-3Rs made 538 crossings in the Summer of 1944. Service extended to Port Lyaute, Morocco. The crews were Pan Am & AOA.

The RAF 231 Squadron also flew the Atlantic using 10, later 12 Coronados. They operated Boucherville/Montreal to Largs, Scotland via either Botwood or Gander. Westbound they had to refuel in Iceland. The RAF made 169 North Atlantic crossings and 51 on the South Atlantic route.

The last RAF Coronado left Largs for Montreal 25 September 1945.

I do not know how many Catalina crossings were made (mostly deliveries to Britain).

If the question is what four-engined flying boat ruled the North Atlantic the answer is the Coronado.

There is a PB2Y-3R at the National Naval Aviation Museum aboard NAS Pensacola, Florida.

Mark Lincoln (talk) 02:14, 9 December 2015 (UTC)

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title: Talk:Sikorsky S-42


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Crip Walk

The Crip Walk, also known as the C-Walk, is a dance move that was created in the 1970s by first generation Crip member Robert "Sugar Bear" Jackson, and has since spread worldwide.

Overview
The dance is primarily an act of performing quick and intricate footwork. The rivalry between the Crips and the Bloods spilled over into the world of entertainment, with the adoption of the gang dance by various rappers on the West Coast of the United States, who gave it its name, the Crip Walk. This dance involves the movement of one's feet, classically to the spelling of C-R-I-P (refer C Walk). It was used by Crips at parties to display affiliation, particularly vis-a-vis rival gang the Bloods. It was also used after killing someone to give the kill a Crip signature. MTV declined to broadcast any music videos that contained the Crip Walk.

Examples

 * Tennis player Serena Williams performed the walk at the 2012 Summer Olympic tennis tournament after defeating Maria Sharapova in the gold-medal match at Centre Court, Wimbledon.
 * The Super Bowl LVI halftime show had a synchronized Crip Walk led by Snoop Dogg.

Variations
There are many variations of the standard Crip Walk, including the Blood Walk, Modern C-Walk, Clown Walk Killwaukee Walk and Crown Walk. The chief differences are in the way moves are executed, from elements such as speed, energy, flow, variations, arm control, and bounce.

Documentaries

 * American rapper CJ Mac released a documentary focused on the beginnings of Crip Walk and its rise in popularity entitled "Cwalk: It's a Way of Livin'". It features such rappers as Snoop Dogg, WC and Ice-T along with original members of the Crips.

title: Crip Walk


text:
Talk:Lithosphere

Older comments
168.212.92.5 17:06, 21 September 2006 (UTC)well i just wanted to put something on this page so yeah, that's it! LOL! Hi! I never done this be4 coolio!!!!!! —Preceding unsigned comment added by 24.24.255.185 (talk) 22:10, 7 December 2008 (UTC)

If the lithospere includes the crust, how can it distinguish itself from the crust??? Ejrrjs | What? 21:32, 16 Feb 2005 (UTC)

Mojo is a distinct change in composition between crust and the rest of the lithosphere. Lithosphere is crust and part of the upper mantle that does not move with the asthenosphere. --DanielCD 22:15, 16 Feb 2005 (UTC)

lithosphere, etc are rheological boundary layers crust, mantle, core, are chemical boundary layers

different things - sometimes they overlap but they are defined by different criteria.

also, just wanted to state that i have been slowly elimated the statements that the mantle is semi-molten, it is a solid and deforms by solid-state creep.

I removed the "Inner core is also solid" sentence for two reasons. It contributed to the common misconception that the asthenosphere or much of the mantle is liquid by emphasizing only that the inner core was solid like the lithosphere (remember, the only molten part of the earth is the outer core (and maybe parts of the extreme lower mantle), and it really has nothing to do with discussion of the lithosphere. The lithosphere would still be defined in the same way and have the same distinguishing characteristics even if the earth had no core at all. Ethan 05:46, 17 December 2005 (UTC)

"There are two types of lithosphere:"

This section...I thought there were two types of _crust_. The lithosphere is always the same thickness since it is defined by the change from brittle to plastic behaviour, which depends on the conditions at depth, thus the lithosphere-asthenosphere boundary is always at the same depth except in subduction zones. 128.232.250.254 00:05, 24 May 2006 (UTC)

 * Geology by Chernicoff & Whitney, 4th ed., page 386, states that average thickness for oceanic lithosphere (=crust plus upper mantle) is 70 km and for continental lithosphere 150 km. You are right that the lithosphere is defined as the brittle topmost layer, but the depth at which this changes to plastic depends on the material present, and this is different in the continental vs. the oceanic setting. The density of the material (which affects pressure) as well as its relationship between temperature and plasticity both play a role.AxelBoldt 00:56, 24 May 2006 (UTC)

ME AND MY EARTH
The Earth's hydrosphere consists chiefly of oceans, but technically includes all water surfaces in the world, including inland seas, lakes, rivers, and underground waters. The average depth of the oceans is 3,794 m (12,447 ft), more than five times the average height of the continents. The mass of the oceans is approximately 1.35 × 1018 tonnes, or about 1/4400 of the total mass of the Earth (ranges reported: 1.347 × 1021 to 1.4 × 1021 kg.[1] )

The abundance of water on Earth is a unique feature that distinguishes our "Blue Planet" from others in the solar system. Approximately 70.8 percent (97% of it being sea water and 3% fresh water[2]) of the Earth is covered by water and only 29.2 percent is landmass. Earth's solar orbit, vulcanism, gravity, greenhouse effect, magnetic field and oxygen-rich atmosphere seem to combine to make Earth a water planet.

Earth is actually beyond the outer edge of the orbits which would be warm enough to form liquid water. Without some form of a greenhouse effect, Earth's water would freeze. Paleontological evidence indicates that at one point after blue-green bacteria (Cyanobacteria) had colonized the oceans, the greenhouse effect failed, and Earth's oceans may have completely frozen over for 10 to 100 million years in what is called a snowball Earth event.

On other planets, such as Venus, gaseous water is destroyed (cracked) by solar ultraviolet radiation, and the hydrogen is ionized and blown away by the solar wind. This effect is slow, but inexorable. This is one hypothesis explaining why Venus has no water. Without hydrogen, the oxygen interacts with the surface and is bound up in solid minerals.

In the Earth's atmosphere, a tenuous layer of ozone within the stratosphere absorbs most of this energetic ultraviolet radiation high in the atmosphere, reducing the cracking effect. The ozone, too, can only be produced in an atmosphere with a large amount of free diatomic oxygen, and so also is dependent on the biosphere (plants). The magnetosphere also shields the ionosphere from direct scouring by the solar wind.

Finally, volcanism continuously emits water vapor from the interior. Earth's plate tectonics recycle carbon and water as limestone rocks are subducted into the mantle and volcanically released as gaseous carbon dioxide and steam. It is estimated that the minerals in the mantle may contain as much as 10 times the water as in all of the current oceans, though most of this trapped water will never be released.

The water cycle describes the methods of transport for water in the hydrosphere. This cycle includes water beneath the Earth's surface and in rocks (lithosphere), the water in plants and animals (biosphere), the water covering the surface of the planet in liquid and solid forms, and the water in the atmosphere in the form of water vapor, clouds, and precipitation. Movement of water within the hydrosphere is described by the hydrologic cycle. It is easy to see this motion in rivers and streams, but it is harder to tell that there is this motion in lakes and ponds.

The water in the oceans moves as it is of different temperature and salinity on different locations. Surface waters are also moved by winds, giving rise to surface ocean currents. Warm water is lighter or less dense than cold water which is more dense or heavier and salty water is also more dense than fresh water. The combination of the water's temperature and salinity determines whether it rises to the surface, sinks to the bottom, or stays at some intermediate depth.

Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. The gases are attracted by the gravity of the body, and held fast if gravity is sufficient and the atmosphere's temperature is low. Some planets consist mainly of various gases, and thus have very deep atmospheres (see gas giants).

Earth, Venus, and Mars have atmospheres that envelop their surfaces, as do three of the satellites of the outer planets: Titan, Enceladus (moons of Saturn), and Triton (a moon of Neptune). In addition, the giant planets of the outer solar system - Jupiter, Saturn, Uranus, and Neptune - are composed predominantly of gases. Other bodies in the solar system possess extremely thin atmospheres. Such bodies are the Moon (sodium gas), Mercury (sodium gas), Europa (oxygen) and Io (sulfur). The dwarf planet Pluto also has an envelope of gas as it approaches close to the Sun, but these gases are frozen for most of its orbit.

The Earth's atmosphere consists, from the ground up, of the Troposphere (which includes the planetary boundary layer or peplosphere as lowest layer), Stratosphere, Mesosphere, Ionosphere (or Thermosphere), Exosphere and the Magnetosphere.

Initial atmospheric makeup is generally related to the chemistry and temperature of the local solar nebula during planetary formation and the subsequent escape of interior gases. These original atmospheres underwent much evolution over time, with the varying properties of each planet resulting in very different outcomes.

Surface gravity, the force that holds down an atmosphere, differs significantly among the planets. For example, the large gravitational force of the giant planet Jupiter is able to retain light gases such as hydrogen and helium that escape from lower gravity objects. Second, the distance from the sun determines the energy available to heat atmospheric gas to the point where its molecules' thermal motion exceed the planet's escape velocity, the speed at which gas molecules overcome a planet's gravitational grasp. Thus, the distant and cold Titan, Triton, and Pluto are able to retain their atmospheres despite relatively low gravities.

Since a gas at any particular temperature will have molecules moving at a wide range of velocities, there will almost always be some slow leakage of gas into space. Lighter molecules move faster than heavier ones with the same thermal kinetic energy, and so gases of low molecular weight are lost more rapidly than those of high molecular weight. It is thought that Venus and Mars may have both lost much of their water when, after being photodissociated into hydrogen and oxygen by solar ultraviolet, the hydrogen escaped. Earth's magnetic field helps to prevent this, as the solar wind greatly enhances the escape of hydrogen.

Other mechanisms that can cause atmosphere depletion are solar wind-induced sputtering, impact erosion, weathering, and sequestration—sometimes referred to as "freezing out"—into the regolith and polar caps.

Moreover, on Earth, atmospheric composition is largely governed by the by-products of the very life that it sustains.

Interstellar planets, theoretically, may also retain thick atmospheres.

The lithosphere (from the Greek for "rocky" sphere) is the solid outermost shell of a rocky planet. On the Earth, the lithosphere includes the crust and the uppermost mantle which is joined to the crust across the Mohorovicic discontinuity. Lithosphere is underlain by asthenosphere, the weaker, hotter, and deeper part of the upper mantle. The base of the lithosphere-asthenosphere boundary corresponds approximately to the depth of the melting temperature in the mantle. As the conductively cooling surface layer of the Earth's convection system, the lithosphere thickens over time. It is fragmented into tectonic plates (shown in the picture), which move independently relative to one another. This movement of lithospheric plates is described as plate tectonics.

The concept of the lithosphere as Earth’s strong outer layer was developed by Barrell, who wrote a series of papers introducing the concept (Barrell 1914a-c). The concept was based on the presence of significant gravity anomalies over continental crust, from which he inferred that there must exist a strong upper layer (which he called the lithosphere) above a weaker layer which could flow (which he called the asthenosphere). These ideas were enlarged by Daly (1940), and have been broadly accepted by geologists and geophysicists. Although these ideas about lithosphere and asthenosphere were developed long before plate tectonic theory was articulated in the 1960's, the concepts that strong lithosphere exists and that this rests on weak lithosphere are essential to that theory.

The division of Earth's outer layers into lithosphere and asthenosphere should not be confused with the chemical subdivision of the outer Earth into mantle, and crust. All crust is in the lithosphere, but lithosphere generally contains more mantle than crust.

There are two types of lithosphere:

Oceanic lithosphere, which is associated with Oceanic crust Continental lithosphere, which is associated with Continental crust Oceanic lithosphere is typically about 50-100 km thick (but beneath the mid-ocean ridges is no thicker than the crust), while continental lithosphere is about 150 km thick, consisting ~50 km of crust and 100km or more of uppermost mantle. Oceanic lithosphere consists mainly of mafic crust and ultramafic mantle and is denser than continental lithosphere, for which the mantle is associated with crust made of felsic rocks. The crust is distinguished from the upper mantle by the change in chemical composition that takes place at the Moho discontinuity. Oceanic lithosphere thickens as it ages and moves away from the mid-ocean ridge. This thickening occurs by conductive cooling, which converts hot asthenosphere into lithospheric mantle, and causes the oceanic lithosphere to become increasingly dense with age. Oceanic lithosphere is less dense than asthenosphere for a few tens of millions of years, but after this becomes increasingly denser than asthenosphere. The gravitational instability of mature oceanic lithosphere has the effect that at subduction zones the oceanic lithosphere invariably sinks underneath the overriding lithosphere, which can be oceanic or continental. New oceanic lithosphere is constantly being produced at mid-ocean ridges and is recycled back to the mantle at subduction zones. As a result, oceanic lithosphere is much younger than continental lithosphere: the oldest oceanic lithosphere is about 170 million years old, while parts of the continental lithosphere are billions of years old.

Another distinguishing characteristic of the lithosphere is its flow properties. Under the influence of the low-intensity, long-term stresses that drive plate tectonic motions, the lithosphere responds essentially as a rigid shell and thus deforms primarily through brittle failure, whereas the asthenosphere (the layer of the mantle below the lithosphere) is heat-softened and accommodates strain through plastic deformation.

Geoscientists can directly study the nature of the subcontinental mantle by examining mantle xenoliths brought up in kimberlite and other volcanic pipes —The preceding unsigned comment was added by 70.186.162.149 (talk) 00:10, 31 January 2007 (UTC).

Moho not mojo
No one ever got their Moho working —The preceding unsigned comment was added by Zyzzy2 (talk • contribs) 04:32, 22 April 2007 (UTC).

2 types of lithosphere
Oh yes the oceanic and continental lithospheres are quite different, and surly the crusts are different but the mantles are distinct as well. Sub-oceanis mantle lithosphere (SOML) is distinctly younger and thinner than sub-continental continental mantle lithosphere (SCML). SCML shows isotopic characteristics of ancient enrichments and depletions —The preceding unsigned comment was added by Zyzzy2 (talk • contribs) 04:39, 22 April 2007 (UTC).

You problem is solved--LouisSS13 (talk) 16:38, 6 July 2009 (UTC)

Second Figure is not useful and should be replaced or at least deleted
This figure is confusing because it doesn't even show the lithosphere. Why confuse people unnecessarily? Zyzzy2 16:23, 26 May 2007 (UTC)Zyzzy2 Like what Zyzzy2 says. Aswell - this picture is used in other Earth layer pages - it's just informatively wrong. —Preceding unsigned comment added by 203.171.195.36 (talk) 22:13, 9 August 2009 (UTC)

Lithosphere part of Tectonic Plate THEORY
It's unclear in the article whether the Lithosphere is a real proven FACT, or merely part of a larger THEORY. As tectonic plates are described as a theory, there should be a more obvious connection to the theoretical nature of the lithosphere. It's true that people are expected to approach Wikipedia with at least some degree of caution, but let's make it clear for the audience.

Unless, of course, I am somehow wrong... As far as I know, the reason plate tectonics are THEORY is because nobody has actually drilled to the center of the earth to take samples. In fact, I don't think we've been able to get very deep at all. Certainly we can call the "top" layer lithosphere if we want, but the article expands on that to include where it places in tectonics, mixing any possible known facts about the lithosphere with theory. - Commandur (talk) 10:03, 19 January 2010 (UTC)

 * The lithosphere is something that is observed. We may not have drilled it to get samples but we have a lot of remote sensed data especially seismic data, on which the lithosphere is well 'imaged' because its base shows up as a marked change in S-wave velocity. The concept of the lithosphere is much older than the theory of Plate tectonics, it was developed about a hundred years ago, so stands on its own. Mikenorton (talk) 18:00, 19 January 2010 (UTC)

 * I hope there is no implication that a 'theory' is an unproved concept. This would be quite wrong and it is not the meaning of the word in science.  As stated the Lithosphere is an Earth Science model to explain the geophysical data (and the petrological data from magmas originating at depth).  This data and the model were used in Geodynamics to make predictions that match both geophysical and topographic data of such things as Island Arcs, Subduction zones, Ocean Ridges, etc.  So it is accepted that it is the best model as it fits the 'facts' extremely well.  —Preceding unsigned comment added by Physics Sensei (talk • contribs) 23:44, 14 May 2010 (UTC)

 * In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system), is the theory, that the Earth is the center of the universe, and that all other objects orbit around it. So I guess geocentricism is not an unproved concept, since it was embraced for like 1500 years. DasV (talk) 19:59, 14 March 2011 (UTC)

Formula under oceanic lithosphere
There is something wrong with the description of the formula under oceanic lithosphere. In the equation the symbol for thermal diffusivity is kappa but in the text it looks like chi, even though in the text for editing the symbol is given as kappa. I don't know how to fix it. —Preceding unsigned comment added by Earthophile (talk • contribs) 00:53, 11 July 2010 (UTC)

Definition of lithosphere asthenosphere boundary
"Lithosphere" has the potential to become a really great article, but it is currently missing a few key topics. The article would benefit from discussions of the effective elastic thickness and how it relates to lithospheric thickness (Burov and Diament, 1995), rheological models of the lithosphere (i.e., yield strength envelopes)(Goetze and Evans, 1979), and the observation that the equation given for lithospheric thickness does not work for lithosphere older than ~80 Ma, possibly due to small-scale convection (Parsons and McKenzie, 1978).

However, I think this article would benefit most from a discussion of the different ways in which the base of the lithosphere is defined. Right now the article suggests that the base of the lithosphere is defined as the brittle-ductile transition (BDT) in olivine, following the mechanical-boundary layer definition of Parsons and McKenzie (1978). However, several other definitions exist including 1) the crust and portion of the mantle which mainly transports heat through conduction rather than convection (i.e., a thermal boundary layer), 2) a rheological boundary defined by compositional differences (e.g., water and/or melt content; this is becoming increasingly well received and should be mentioned), and 3) the seismically fast, elastically anisotropic lid (i.e., seismic lithosphere). An excellent review is given by Fischer et al. (Annual Reviews of Earth and Planetary Sciences, 2010).

Although the definition currently provided is worth mentioning, statements such as "the lithosphere remains rigid for very long periods of geologic time in which it deforms elastically and through brittle failure" reflect the outdated perspective of the article as written. — Preceding unsigned comment added by Larhansen (talk • contribs) 16:44, 10 April 2011 (UTC)

Mineral content?
I was hoping for a list of the most common elements and their concentrations in the lithosphere. I was reading an old geology text (c. 1950's) that listed Oxygen and Silicon as the most common, and gave percentages. However, I was unclear if those were proportions by mass, or by volume. I was hoping Wiki could help me out. Perhaps someone could add that information for future readers. — Preceding unsigned comment added by 2602:30A:C08C:A6F0:21C:B3FF:FEC3:2572 (talk) 13:19, 19 February 2014 (UTC)
 * Typically given as mass percent, see Crust (geology). Vsmith (talk) 13:39, 19 February 2014 (UTC)

Rheology
I've always thought of "rheology" as encompassing fluid flow, plastic deformation, elasticity, and even brittle failure. As a student, I used this book by Ranalli: , where all of these concepts are discussed in the context of the Earth. Yet, when I visit the wikipage Rheology the focus there is on fluid flow and plasticity, not on elasticity and brittleness. Any thoughts on this? Isambard Kingdom (talk) 15:32, 11 July 2015 (UTC)

 * Strictly, flow is what it's about. However, materials show a wide range of behaviour including some elasticity - Bingham plasticity is one type of behaviour that is sometimes used to describe how the lithosphere deforms. More generally the term rheid gets used for the typically time dependent behaviour of rocks, although less often than perhaps it should. I think that earth scientists use rheology in a slightly broader sense than engineers. Mikenorton (talk) 16:16, 11 July 2015 (UTC)

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Is oceanic crust moves? because, only continental plates are moving in the Pangaea.. — Preceding unsigned comment added by 49.149.85.167 (talk) 09:51, 27 June 2018 (UTC)

title: Talk:Lithosphere


text:
Talk:Mythical Beasts

i am intending to add more content to this page so please DON'T delete it.

 * please note the existence of List of species in fantasy fiction and list of species in folklore and mythology. This page overlaps with both. I am going to merge anything that needs merging with those two pages and turn this into a redirect to legendary creature. —Charles P. (Mirv) 23:17, 7 Feb 2005 (UTC)

title: Talk:Mythical Beasts


text:
Image sharing

Image sharing, or photo sharing, is the publishing or transfer of digital photos online. Image sharing websites offer services such as uploading, hosting, managing and sharing of photos (publicly or privately). This function is provided through both websites and applications that facilitate the upload and display of images. The term can also be loosely applied to the use of online photo galleries that are set up and managed by individual users, including photoblogs. Sharing means that other users can view but not necessarily download images, and users can select different copyright options for their images.

While photoblogs tend only to display a chronological view of user-selected medium-sized photos, most photo sharing sites provide multiple views (such as thumbnails and slideshows), the ability to classify photos into albums, and add annotations (such as captions or tags).

Desktop photo management applications may include their own photo-sharing features or integration with sites for uploading images to them. There are also desktop applications whose sole function is sharing images, generally using peer-to-peer networking. Basic image sharing functionality can be found in applications that allow you to email photos, for example by dragging and dropping them into pre-designed templates.

Photo sharing is not confined to the web and personal computers, but is also possible from portable devices such as camera phones, either directly or via MMS. Some cameras now come equipped with wireless networking and similar sharing functionality themselves.

History
The first photo sharing sites originated during the mid to late 1990s, primarily from services providing online ordering of prints (photo finishing), but many more came into being during the early 2000s with the goal of providing permanent and centralized access to a user's photos, and in some cases video clips too. Webshots, SmugMug, Yahoo! Photos and Flickr were among the first. This has resulted in different approaches to revenue generation and functionality among providers.

In 1995, Webshots was one of the first online photo sharing platforms. Webshots offered an easy-to-use interface and basic photo editing tools. In 2002, SmugMug was founded, focusing on providing a high-quality photo sharing experience for professional photographers. SmugMug offers features such as custom photo galleries and e-commerce options. In 2003, Yahoo! Photos was one of the most popular photo sharing platforms thanks to its integration with Yahoo's email and search services. In 2004, Flickr was founded, quickly becoming popular due to its vibrant photography community and effective tagging system.

The 2010s saw the rise of mobile apps and cloud storage. The advent of smartphones with high-quality cameras and the availability of cloud storage services such as Google Photos, Dropbox, and iCloud Photo Library revolutionized the way people take, store, and access their photos. Mobile apps such as Instagram, Snapchat, and TikTok emerged, offering a simple and socially focused photo sharing experience. These apps met the need for instant sharing with friends and followers.

In recent years, AI and machine learning have become increasingly integrated into photo sharing platforms. AI is being used to improve image quality, automatically tag images with relevant keywords, detect and filter inappropriate content, and create new effects and filters. AI has the potential to revolutionize the way people share photos, making it easier for them to share better-looking images and find relevant images.

Revenue models
Image sharing sites can be broadly broken up into two groups: sites that offer photo sharing for free and sites that charge consumers directly to host and share images.

Of the sites that offer free photo sharing, most can be broken up into advertising-supported media plays and online photo finishing sites, where photo sharing is a vehicle to sell prints or other merchandise. These designations are not strict, and some subscription sites have a limited free version. Consumers can share their photos directly from their home computers over high speed connections through peer-to-peer photo sharing using applications. Peer-to-peer photo sharing often carries a small one-time cost for the software. Some sites allow you to post your pictures online and they will then project the image onto famous buildings during special events, while other sites let you insert photos into digital postcards, slide shows and photo albums and send them to others.

Some free sites are owned by camera manufacturers, and only accept photos made with their hardware.

Subscription-based
In return for a fee, subscription-based photo sharing sites offer their services without the distraction of advertisements or promotions for prints and gifts. They may also have other enhancements over free services, such as guarantees regarding the online availability of photos, more storage space, the ability for non-account holders to download full-size, original versions of photos, and tools for backing up photos. Some offer user photographs for sale, splitting the proceeds with the photographer, while others may use a disclaimer to reserve the right to use or sell the photos without giving the photographer royalties or notice.

Some image sharing sites have begun integrating video sharing as well.

Peer-to-peer
With the introduction of high speed (broadband) connections directly to homes, it is feasible to share images and videos without going through a central service. The advantages of peer-to-peer sharing are reduced hosting costs and no loss of control to a central service. The downsides are that the consumer does not get the benefit of off-site backup; consumer Internet service providers (ISPs) often prohibit the serving of content both by contract and through the implementation of network filtering, and there are few quality guarantees for recipients. However, there are typically no direct consumer costs beyond the purchase of the initial software, provided the consumer already has a computer with the photos at home on a high speed connection. Applications like Tonido provide peer-to-peer photo sharing.

Peer-to-server
Operating peer-to-peer solutions without a central server can create problems as some users do not leave their computers online and connected all the time. Using an always-on server like Windows Home Server which acts as an intermediate point, it is possible to share images peer-to-peer with the reliability and security of a central server. Images are securely stored behind a firewall on the Windows Home Server and can be accessed only by those with appropriate permissions.

Peer-to-browser
A variation on the peer-to-peer model is peer-to-browser, whereby images are shared on one PC with the use of a local (on the host computer) software service (much like peer-to-peer) but made available to the viewer through a standard web browser. Technically speaking, this may still be described as peer-to-peer (with the second peer being a web browser) but it is characteristically different as it assumes no need to download peer software for the viewer. Photos are accessed by regular URLs that standard web browsers understand natively without any further software required. Consequently, photos shared in this way are accessible not only to users who have downloaded the correct peer software (compatible with the software in use by the sharer).

Peer-to-browser sharing has (similar to peer-to-peer) reduced hosting costs, no loss of control to a central service, and no waiting for files to upload to the central service. Furthermore, universal web browser access to shared files makes them more widely accessible and available for use in different ways, such as embedding in, or linking to, from within web pages. As with peer-to-peer, the downsides are lack of off-site backup, possible inhibition by some ISPs, and limitations in speed of serving.

Social networks
With the emergence of social networks, image sharing has now become a common online activity. For example, in Great Britain, 70% of online users engaged in image sharing in 2013; 64% of British users shared their photos through a social network. Facebook stated in 2015 that there were approximately two billion images uploaded to its service daily. In terms of image sharing, Facebook is the largest social networking service. On Facebook, people can upload and share their photo albums individually, and collaboratively with shared albums. This feature allows multiple users to upload pictures to the same album, and the album's creator has the ability to add or delete contributors. Twitter collaborated with Photobucket in developing a new photo sharing service so users can attach a picture to a tweet without depending on another application such as TwitPic or Yfrog. As of June 2016, there were more than 500 million monthly active Instagram users.

Link aggregation sites
Image sharing on social news and image aggregation sites such as Reddit, Imgur, 4chan, Pinterest and Tumblr allow users to share images with a large community of users. Images are the most liked content of the aggregation and media sharing site Reddit; and according to data analyst Randy Olson as of August 2014, nearly 2/3 of all successful posts on the site were links to an image hosted on Imgur.

Mobile
Sharing images via mobile phones has become popular. Several networks and applications have sprung up offering capabilities to share captured photos directly from mobile phones to social networks. The most prominent of these is Instagram, which has quickly become the dominant image sharing-centric social network with over 500 million members. Other applications and networks offering similar service and growing in popularity include Streamzoo, Path, PicsArt, Piictu, and Starmatic.

Apps
Instagram, Snapchat, and Nice are examples of photo sharing apps with millions of users.

Web photo album generators
Software can be found on the Internet to generate digital photo albums, usually to share photos on the web, using a home web server. In general, this is for advanced users that want to have better control over the appearance of their web albums and the actual servers they are going to run on.

Image classification
Image sharing sites usually propose several ways to classify images. Most sites propose at least a taxonomy where images can be grouped within a directory-like structure in so-called "galleries". Some sites also allow users to classify images using tags to build a folksonomy. Depending on the restrictions on the set of users allowed to tag a single document and the set of tags available to describe the document, one speaks about narrow and broad folksonomies. A folksonomy is broad when there is no restriction on the set of taggers and available tags. When there are limitations, the folksonomy is called narrow. Another mechanism is coupling taxonomy and folksonomy, where tags associated to galleries and artists are cascaded to the galleries and artist's pictures. Broad taxonomies have interesting properties like the power law.

The use of Artificial Intelligence to classify uploaded photos by subject, theme, or location is a prominent feature of Raise that Canon-USA launched early March 2019.

Photo tagging
Photo tagging is the process that allows users to tag and group photos of an individual or individuals. With facial recognition software tagging photos can become quicker and easier; the more tagging done of an individual the more accurate the software can be. This type of software is currently in use on Facebook. Photo tagging is a way of labeling photos so that viewers can know who is who in the picture. On most online photo sharing sites such as Facebook, a tag can also be used as a link that when clicked will take you to the person's profile that was tagged. Most of the time photos can only be tagged by the user to uploads the photo but on some sites photos can be tagged by other users as well. These tags can be searched for across the entire Internet, on separate websites or in private data bases. They can be used for crowdsourced classification (see the section on image classification) but can also play a socio-cultural role in that they can establish neologisms, Internet memes, snowclones, slogans, catch phrases, shared vocabularies and categorizations as well as producing comedic twists, contexts and perspectives of the presented images, and hence often play a significant role in the community building and identity formation of and the entertainment in online communities that allow the creation of broad folksonomies.

Geotagging
Geotagging a photo is the process in which a photo is marked with the geographical identification of the place it was taken. Most technology with photo taking capabilities are equipped with GPS system sensors that routinely geotag photos and videos. Crowdsourced data available from photo-sharing services have the potentiality of tracking places. Geotagging can reveal the footprints and behaviors of travelers by utilizing spatial proximity of geo-tagged photos that are shared online, making it possible to extract travel information relating to a particular location. Instagram, Flickr, and Panoramio are a few services that provide the option of geotagging images. Flickr has over 40 million geotagged photos uploaded by 400 thousand users, and still growing at a rapid pace. Some sites including Panoramio and Wikimedia Commons show their geocoded photographs on a map, helping the user find pictures of the same or nearby objects from different directions.

Criticism
Critics of image/photo sharing are concerned with the use of applications such as Instagram, because they believe that the behaviors portrayed on these sites could potentially be linked to the narcissism trait. Keen argues that "Self" is running digital culture, and he states that people use social-media platforms because they are interested in advertising themselves. Buffardi and Campbell (2008) also alleged that Instagram offers "a gateway for self-promotion via self-descriptions, vanity via photos, and a large amount of shallow relationships." However, they later said that the large number of users suggests the general psychology of the members is normative.

Privacy
Privacy activists and researchers have noted that the sharing of images on social networks may compromise the privacy of people depicted in them. Further, most current social networks afford their users little control over content that they did not post themselves. In its privacy policy, Facebook states that any information posted using its service, including images, may be used to display relevant ads to its users. Facebook utilizes automatic facial recognition software that can automatically recognize the face of another Facebook user in new photos, and suggest that the user be tagged in the photo. A Ghent University study found that employers commonly search for prospective employees on Facebook, and may decide whether or not to grant an interview based on the person's profile picture.

Purposes
The increasing ease of use has encouraged image sharing in insurance, including crop insurance. The insurance company and farmer have a shared interest in the current state of a field. This method allows crop health to be monitored more quickly and easily than any other way.

title: Image sharing


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Giorgos Toussas

Giorgos Toussas (Γιώργος Τούσσας) (born 8 September 1954) is a Greek politician and Member of the European Parliament (MEP) for the Communist Party of Greece; part of the European United Left–Nordic Green Left. He was born in Koilada.

title: Giorgos Toussas


text:
Dimitrios Papadimoulis

Dimitrios Papadimoulis (Δημήτρης Παπαδημούλης; born 21 March 1955) is a Greek politician and Member of the European Parliament (MEP) as a member of The Left in the European Parliament – GUE/NGL.

On 18 January 2022, he was re-elected as vice-president of the European Parliament for the fourth consecutive time, with the support of a broad cross-party majority and with a 74.77% share of the vote, garnering 492 positive votes out of a total of 658 valid ballots. Since 2014 he is the only Greek and the only representative from the GUE-NGL political group at the Presidium of the European Parliament.

According to the VoteWatch.EU, he is the most influential Greek MEP in the European Parliament.

In 2020, he was included at the Top 10 most influential MEPs in the European Parliament (9th place) in a list of 100 MEPs from the 705 EP and 27 Member States. The SYRIZA MEP was first in his political group (European United Left / Nordic Green Left) but also first among Greek MEPs.

Born in 1955 in Athens. Graduated with distinction from Varvakeio Junior High School of Athens and studied with scholarship at the School of Civil Engineering of NTUA (National Technical University of Athens). He has worked as an engineer and business executive (1980-2004). Since the age of 18 and his student days, he participates actively and joins the left movement, where he remains since then.

 * Member of the Presidium of the Central Committee of National Student Union of Greece (1976-1979), of the leadership of the Communist youth organization "Rigas Feraios" and later at the leadership of the "Greek Communist Party of the Interior" (Eurocommunist) and political party of E.AR ("Greek Left").
 * Member of the Joint Committee who prepared the common Report between E.AR and the Communist Party of Greece (1988), which led to the formation of the Coalition of the Left. - - Member of the elected leading bodies of the Coalition of the Left - since its formation as a single party (1992)- and later SYRIZA.
 * He was elected to the European Parliament (2004-2009) and the Greek Parliament (2009-2014).
 * Member of the Parliamentary Assembly of the Council of Europe (2009-2014) and Vice President of the Group of the Unified European Left (UEL).
 * He was re-elected as MEP in the 2014 European elections. At the suggestion of Alexis Tsipras, he was unanimously elected head of the SYRIZA delegation at the European Parliament.
 * In July 2014, he was elected vice-president of the European Parliament with a percentage of positive votes 42.1%. He was re-elected Vice President in January 2017 with a new percentage of positive votes measuring 73.5%.

•	In the Parliamentary Evaluation Report on the term 2014–2019, published by "Vote Watch Europe", Dimitris Papadimoulis was evaluated as the Greek MEP with the greatest influence on the European Institutions. In an earlier report by VoteWatch.EU, he was also one of the three most active MEPs in the entire European Parliament, for the period 2004–2009.

Member of European Parliament. Elected first, with the highest number of votes among the SYRIZA-Progressive Alliance MEPs (272.835 votes). Head of the SYRIZA delegation at the EP.
 * 2019 - now
 * Vice President of the European Parliament with a percentage of 60.5%.

He is a full member of the Committee on Economic and Monetary Affairs (ECON) and the Committee on Budgets (BUDG) and a substitute member of the Committee on Regional Development (REGI).

Early life
Papadimoulis studied engineering at the National Technical University of Athens.

Career
Papadimoulis was an MEP from 2004 to 2009.

From 2009 to 2014 he was a member of the Greek parliament.

Since 2014, he has again been an MEP.

Since 1 July 2014, he has been one of the simultaneous 14 as Vice President of the European Parliament.

Vice-President of the European Parliament Head of the SYRIZA delegation Member of the European Parliament's "Progressive Caucus" steering committee

From 2014 he is the only Greek and the only representative from the GUE-NGL political group at the Presidium of the European Parliament. According to the VoteWatch.EU, he is the most influential Greek MEP in the European Parliament.

Born in 1955 in Athens. Graduated with distinction from Varvakeio Junior High School of Athens and studied with scholarship at the School of Civil Engineering of NTUA (National Technical University of Athens). He has worked as an engineer and business executive for 25 years (1980-2004). He is married to Nadia Soubasaki and they have two children.

•	His first term in the European Parliament was in 2004–2009, and shortly afterwards he was elected in the Greek Parliament in 2009 and 2012 (2009-2014).

•	Ηe was re-elected as an MEP in the 2014 European elections. At the suggestion of Alexis Tsipras, he was unanimously elected head of the SYRIZA delegation at the European Parliament. In July 2014, he was elected vice-president of the European Parliament with a percentage of 42.1%. He was re-elected Vice President in January 2017 with a percentage of 73.5%.

•	In May 2019, he was elected first, with the highest number of votes from the SYRIZA-Progressive Alliance MEPs and took over as head of the SYRIZA delegation at the European Parliament. In July 2019 he was re-elected Vice President of the European Parliament with a percentage of 60.5%.

He is a regular member of the Committee on Economic and Monetary Affairs (ECON) and a substitute member of the Committee on Regional Development (REGI).

title: Dimitrios Papadimoulis


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Thanasis Pafilis

Athanasios Pafilis (Greek: Αθανάσιος Παφίλης) (born 8 November 1954 ) is a Greek communist politician, member of the Hellenic Parliament and member of the central committee of the Communist Party of Greece. He is also the General Secretary of the World Peace Council and was briefly also a Member of the European Parliament (MEP).

Biography
Pafilis was born on 8 November 1954 in the village of Pitsio of Phtiotida. He grew up in a left-wing family and his father was a member of ELAS and participated in the Greek resistance during the Axis occupation of Greece, and in the Civil War as a member of the Democratic Army. About five people of his family were killed in the civil war. When he was 12 he left his village and moved to Athens where he worked in a Construction site. He was a supporter of the Greek Communist Party from his childhood. He is a law graduate from the Aristotle University of Thessaloniki.

Political career
He joined the Communist Youth of Greece during the Greek Dictatorship and witnessed the Polytechnic uprising.

He was elected to the Greek Parliament in June 1989 with Synaspismos for Phthiotida, and re-elected in November 1989 and April 1990. On 16 July 1991, he switched affiliation and joined the Communist Party of Greece (KKE).

He is a member of the Central Committee of KKE since 1991 and General Secretary of EEDYE, the Greek branch of the World Peace Council. Between 2002 and 2004 he was a local councillor of the Athens Prefecture.

He was elected Member of the European Parliament for Greece in 2004 with KKE, and sat with the European United Left–Nordic Green Left. He was re-elected to the European Parliament in July 2009, but resigned on 13 October 2009 after being elected to the Greek Parliament with KKE, and he has since been a member of the Hellenic Parliament.

title: Thanasis Pafilis


text:
Diamanto Manolakou

Diamanto Manolakou (Διαμάντω Μανωλάκου; born 1 March 1959, in Piraeus) is a Greek politician. She was elected as a Member of the European Parliament (MEP) for the Communist Party of Greece in the 2004 European elections, an office she held until 5 June 2008, when she resigned in favor of Costas Droutsas. She sat with the European United Left–Nordic Green Left. She resigned in order to take a seat in the Hellenic Parliament, one previously held by Elpida Pantelaki. She was re-elected to the Hellenic Parliament in 2009, May and June 2012, January and September 2015, 2019, May 2023 and June 2023.

title: Diamanto Manolakou


text: User talk:64.30.197.197

title: User talk:64.30.197.197


text:
Alisea Airlines

Alisea Airlines was a charter airline based in Italy, which was established in 1999 as Italfly. Flight operations only took place during a brief period between 2002 and 2003.

Fleet
Over the years, Alisea Airlines operated the following aircraft types:

title: Alisea Airlines


text:
User:DarkgreenOrange

Honestly, I can't believe you made it here.

title: User:DarkgreenOrange


text: Category:High schools in Maryland

title: Category:High schools in Maryland


text:
Barry Lyons (baseball)

Barry Stephen Lyons (born June 3, 1960) is an American former professional baseball catcher. He played ten seasons in Major League Baseball (MLB) from 1986 to 1995 for the New York Mets, Los Angeles Dodgers, California Angels, and Chicago White Sox.

Amateur career
Lyons was born in Biloxi, Mississippi, graduated from Biloxi High School and attended Delta State University where he was an NCAA All-American catcher. In 1979 and 1981, he played collegiate summer baseball with the Harwich Mariners of the Cape Cod Baseball League and was named a league all-star in 1981. He was taken in the 25th round of the 1981 Major League Baseball Draft by the Detroit Tigers but did not sign. He was then taken in the 15th round of the 1982 draft by the Mets and agreed to a contract.

Early Mets career
Lyons came up slowly through the Mets' minor leagues while batting near or above .300 from 1983 to 1986. As a sign of the Mets' coming years of dominance, Lyons was on minor league teams that won championships at the A, AA and AAA levels. Lyons was named the Most Valuable Player of the South Atlantic League in 1984.

Lyons moved one big step down the catching depth chart when the Mets traded for the Montreal Expos' superstar catcher, Gary Carter, before the 1985 season. Lyons spent most of the Mets' 1986 championship season playing for the AAA Tidewater Tides but was brought up to the majors early on. Fellow Tidewater catcher Ed Hearn was also brought up early in 1986 and hit well, pushing Lyons down to third-string. Consequently, Lyons only managed to play in six games, including two starts – all before July – and never got a hit for the eventual World Champions. Despite his lack of playing time, Lyons and a few other rarely used players on that 1986 Mets team eventually received belated World Series rings in 1995, nine years after the series.

Fighting for a Mets job
Ed Hearn was traded to the Kansas City Royals shortly before the 1987 season in a one-sided trade that brought eventual star pitcher David Cone to the Mets. More importantly for Lyons, the trade gave him sole backup duty and he played in 53 games, batting .254 with 24 runs batted in in 1987.

In June 1987, Lyons faced Tom Seaver in a simulated game while Seaver was attempting a comeback. Lyons went 6-for-6 against Seaver and Seaver decided to end his comeback attempt. At his retirement press conference, Seaver said Lyons was the best hitter he ever faced.

On Thursday, August 20, in a day game at Shea Stadium against the San Francisco Giants, Lyons came to bat with his team down 4–3, and hit a grand slam to give the Mets a 7–4 lead, which went on to become the final score.

Lyons was back to sharing backup duties in 1988 and 1989 when the Mets traded for Mackey Sasser. In 1989, the aging Carter missed ten weeks after surgery, giving Lyons a shot at starting, but Lyons soon injured his foot. Sasser used the opportunity to prove himself as a starter. Despite the missed opportunity, Lyons had career highs of 79 games and 235 at bats in 1989 but only managed a .247 average with 27 runs batted in. It was the only season in which he led the team in games caught.

After 1989, the 35-year-old Carter was released, and Lyons was in a two-way battle with Sasser for starting duties. Lyons got most of the starts early in 1990 but hit terribly. Although he was an excellent defensive catcher, always appreciated by the Mets' pitching staff, Sasser was clearly the better hitter and quickly became the regular starter. While Sasser wound up at .307 for 1990, Lyons' sub-.240 average prompted the Mets to release him in early September, and his career was all-but-over at age 30.

Winding down
Between his release and the end of 1991, Lyons played in only fourteen games at the Major League level for the Los Angeles Dodgers and California Angels. He spent the next three seasons exclusively playing AAA level baseball – 1992 with the Houston Astros, 1993 with the St. Louis Cardinals and 1994 with the Cincinnati Reds.

In 1995, Lyons had one last strong showing with the Chicago White Sox. With starting catcher Ron Karkovice hitting under .220, 35-year-old backup Mike LaValliere slowing down and the White Sox essentially out of the postseason hunt, Lyons was given a few starts in August and responded with a six-game hitting streak and the third game of his career with four runs batted in. He continued hitting well and even had the only game with five runs batted in during late September. Lyons played four more games before the season ended and, despite posting career-highs in average (.266), slugging average (.531) and home runs (five), was released by the White Sox in November. He signed with the Texas Rangers but retired without playing again at age 35.

After retirement
Instead of playing for the Rangers in 1996, Lyons became a minor league manager for the next three years. He was the manager of the Cincinnati Reds' A-level Charleston Alley Cats in 1998 when he left the team after being denied a promotion. He then spent three years in Nashville, Tennessee broadcasting for the Nashville Sounds as well as running a baseball academy.

In 2002, Lyons moved back to his hometown of Biloxi and became involved in efforts to bring professional baseball back to Mississippi's coast where no team had played since 1928. In 2004, he was the general manager for the inaugural season of the amateur Cotton State League's Biloxi Breeze.

Lyons was married in the early 1990s and had a daughter in the late 1990s. He, his family and his father as well as his efforts to bring professional baseball to southern Mississippi were severely affected by Hurricane Katrina. The storm devastated the Mississippi coast and Lyons' home in 2005. He and his family rode out the storm and lost their house and memorabilia – including his 1986 World Series ring – but all survived.

Beginning in 2014, Lyons succeeded in bringing Minor League Baseball back to Biloxi. The Milwaukee Brewers AA-affiliate Huntsville Stars relocated to Biloxi and were renamed the Biloxi Shuckers. The Shuckers played their first game in Biloxi on June 6, 2015.

On December 15, 2022, Lyons was announced as the manager of the Lexington Counter Clocks of the Atlantic League of Professional Baseball for the 2023 season.

Personal life
Lyons grew up the youngest of four boys, all star athletes. Injuries ended his brothers' careers, and Barry was the only one who turned professional.

Lyons's first marriage, to his wife Marsha, produced a daughter, but ended in divorce, strained by Lyons's depression, drinking and drug use.

After years of struggling, he went through treatment in 2012, becoming sober and becoming religious, then marrying his second and current wife, Julie, that same year. The couple lives in Biloxi, Mississippi.

title: Barry Lyons (baseball)