SUMMARY / RELATED TOPICS

Jumping

Jumping or leaping is a form of locomotion or movement in which an organism or non-living mechanical system propels itself through the air along a ballistic trajectory. Jumping can be distinguished from running and other gaits where the entire body is temporarily airborne, by the long duration of the aerial phase and high angle of initial launch; some animals, such as the kangaroo, employ jumping as their primary form of locomotion, while others, such as frogs, use it only as a means to escape predators. Jumping is a key feature of various activities and sports, including the long jump, high jump and show jumping. All jumping involves the application of force against a substrate, which in turn generates a reactive force that propels the jumper away from the substrate. Any solid or liquid capable of producing an opposing force can serve as a substrate, including ground or water. Examples of the latter include dolphins performing traveling jumps, Indian skitter frogs executing standing jumps from water.

Jumping organisms are subject to significant aerodynamic forces and, as a result, their jumps are governed by the basic physical laws of ballistic trajectories. While a bird may jump into the air to initiate flight, no movement it performs once airborne is considered jumping, as the initial jump conditions no longer dictate its flight path. Following the moment of launch, a jumper will traverse a parabolic path; the launch angle and initial launch velocity determine the travel distance and height of the jump. The maximum possible horizontal travel distance occurs at a launch angle of 45 degrees, but any launch angle between 35 and 55 degrees will result in ninety percent of the maximum possible distance. Muscles do physical work, adding kinetic energy to the jumper's body over the course of a jump's propulsive phase; this results in a kinetic energy at launch, proportional to the square of the jumper's speed. The more work the muscles do, the greater the launch velocity and thus the greater the acceleration and the shorter the time interval of the jump's propulsive phase.

Mechanical power and the distance over which that power is applied are the key determinants of jump distance and height. As a result, many jumping animals have long legs and muscles that are optimized for maximal power according to the force-velocity relationship of muscles; the maximum power output of muscles is limited, however. To circumvent this limitation, many jumping species pre-stretch elastic elements, such as tendons or apodemes, to store work as strain energy; such elastic elements can release energy at a much higher rate than equivalent muscle mass, thus increasing launch energy to levels beyond what muscle alone is capable of. A jumper may be either moving when initiating a jump. In a jump from stationary, all of the work required to accelerate the body through launch is done in a single movement. In a moving jump or running jump, the jumper introduces additional vertical velocity at launch while conserving as much horizontal momentum as possible. Unlike stationary jumps, in which the jumper's kinetic energy at launch is due to the jump movement, moving jumps have a higher energy that results from the inclusion of the horizontal velocity preceding the jump.

Jumpers are able to jump greater distances when starting from a run. Animals use a wide variety of anatomical adaptations for jumping; these adaptations are concerned with the launch, as any post-launch method of extending range or controlling the jump must use aerodynamic forces, thus is considered gliding or parachuting. Aquatic species display any particular specializations for jumping; those that are good jumpers are adapted for speed, execute moving jumps by swimming to the surface at a high velocity. A few aquatic species that can jump while on land, such as mud skippers, do so via a flick of the tail. In terrestrial animals, the primary propulsive structure is the legs, though a few species use their tails. Typical characteristics of jumping species include long legs, large leg muscles, additional limb elements. Long legs increase the time and distance over which a jumping animal can push against the substrate, thus allowing more power and faster, farther jumps. Large leg muscles can generate greater force.

In addition to elongated leg elements, many jumping animals have modified foot and ankle bones that are elongated and possess additional joints adding more segments to the limb and more length. Frogs are an excellent example of all three trends: frog legs can be nearly twice the body length, leg muscles may account for up to twenty percent of body weight, they have not only lengthened the foot and thigh, but extended the ankle bones into another limb joint and extended the hip bones and gained mobility at the sacrum for a second'extra joint'; as a result, frogs are the undisputed champion jumpers of vertebrates, leaping over fifty body lengths, a distance of more than eight feet. Grasshoppers use elastic energy storage to increase jumping distance. Although power output is a principal determinant of jump distance, physiological constraints limit muscle power to 375 Watts per kilogram of muscle. To overcome this limitation, grasshoppers anchor their legs via an internal "catch mechanism" while their muscles stretch an elastic apodeme.

When the catch is released, the apodeme releases its energy

Operation Culverin

Operation Culverin was a planned operation in World War II, in which Allied troops would recapture the northern tip of Sumatra from the Japanese. "Culverin" was a code name for "Operations against northern Sumatra / Malaya" and "First Culverin" was "Operations against northern Sumatra" alone. It was never carried out. Lack of resources prevented it being mounted as planned, other events made it unnecessary; the idea was first put forward by Winston Churchill at the Quebec Conference on August 20, 1943 for an operation in May and June 1944. He was dissatisfied by the existing scope of Allied plans for the South East Asian Theatre for 1943 and 1944. In his vision, by seizing northern Sumatra, "we should be striking and seizing a point of our own against which the Japanese would have to beat themselves if they wished to avoid the severe drain which would be imposed on their shipping by our air action from Sumatra". At this point, no detailed staff study of the operation had been made and the Combined Chiefs of Staff were opposed.

The matter was allowed to lapse. It was revived in February, 1944 when a delegation from Admiral Mountbatten, the Supreme Commander of the South East Asia Command, reported to the Defence Committee in London. Mountbatten proposed amphibious operations in cooperation with the American South West Pacific Area. "Culverin" would be a necessary first part of this plan. But Mountbatten and the British Chiefs of Staff saw three objections to "Culverin". I. G. S. said that only "Vanguard" could kill "Champion". And "Vanguard" was a complement to preliminary operations further north. A decision had to be made by 1 September; the American Joint Chiefs of Staff did not favour "Culverin". In part this was because Mountbatten's Deputy Supreme Commander, the American General Joseph Stilwell, had sent a separate mission to Washington to represent his own differing views to the Joint Chiefs of Staff. In the event, most of the Imperial Japanese Navy's battleships and cruisers were transferred to Singapore at about the same time.

As amphibious operations depended on local naval superiority, "Culverin" had to be abandoned. The Royal Navy could not reinforce their fleet in the Indian Ocean with sufficient strength to face the Japanese main battle fleet, the United States Navy was committed to operations in the Central Pacific and South West Pacific, unwilling to divert their fleets from the Pacific; the South East Asia Command was far more cautious in its estimates for resources required for successful amphibious operations than Churchill. For the much less ambitious Operation Buccaneer, the proposed capture of the Andaman Islands, they proposed a land force of 50,000 men, where Churchill had assumed that only a single division would be necessary. Since no land-based air support would be available until a large beachhead had been secured, Mountbatten demanded the use of every aircraft carrier possessed by the Royal Navy, which would have had adverse effects on other operations. In the middle of 1945, the matter was dropped.

The Japanese fleet had been destroyed or immobilised, but the preferred plan was Operation Zipper, a landing on the coast of Malaya. The final major landing in the area was the May 1945 assault on Operation Dracula. Closing the Ring, Vol. 5 of Winston Churchill's memoirs of World War II. Jon Latimer, Burma: The Forgotten War, London: John Murray, 2004 ISBN 0-7195-6576-6 Alanbrooke, Field Marshal Lord. War Diaries 1939–1945. Phoenix Press. ISBN 1-84212-526-5. Ehrman, John. Grand Strategy Volume V. London: Her Majesty’s Stationery Office

Steven Lang (comics)

Steven Lang is a fictional character, a supervillain appearing in American comic books published by Marvel Comics. He is a manufacturer of the mutant-hunting robots called Sentinels, he first appeared in X-Men #96. Dr. Steven Lang is a pioneer in the field of genetic mutation who hates mutants. An employee of the U. S. government, he is placed in charge of a federal investigation into the origin of genetic mutation. He plans to use his talents to create an army of mutant hunting robots to kill all mutants. To this end, he seeks to get the government to financially support his operations. Lang begins by targeting mutant criminals such as Mesmero, he claims possession of Bolivar Trask's wrecked Sentinel base and its resources, is backed by Ned Buckman and the "Council of the Chosen," the secret group in control of the New York Branch of the Hellfire Club prior to Sebastian Shaw's takeover. To defeat his main targets, the X-Men, Lang creates the "X-Sentinels," android doubles of Professor X and the original X-Men.

However, the X-Sentinels manage only inferior imitations of the X-Men's powers, are defeated by the new X-Men. Jean Grey telekinetically forces Lang to crash his mini-gunship into a wall-screen, he is left in a coma with severe brain damage. During this time, Lang's brain is used as a template for the minds of two sentinels, Conscience and a new Master Mold, both of whom are destroyed in an attempt to release a virus which would have killed all mutants and 97% of normal humans on Earth. Years Lang returns as a member of the Phalanx, a group of humans, transformed into techno-organic human-alien hybrids; the transformation process restores Lang's mind, he becomes their leader. Lang is the only one of the Phalanx to retain his individual human identity due to the brain damage. While he is ardent in his desire to see mutants eradicated, he comes to realize the Phalanx are a danger to humans as well, he conspires with the X-Men to destroy the Phalanx citadel on Earth, following which he is dragged to his apparent death by his lieutenant, Cameron Hodge.

Lang's corpse is reanimated by Bastion using a Technarch. He joins a group formed by the foremost anti-mutant leaders under Bastion's control. During the Second Coming storyline, Steven Lang, alongside Graydon Creed, is killed by Hope Summers; as a normal human being Stephen Lang had no superhuman powers. However, he was a genius and pioneer in the field of robotics, with adequate financial resources to fund his operations; as a member of the Phalanx he had all of the characteristics of a techno-organic life form: enhanced strength and agility, ability to re-shape corporeal form at will, to infect other beings with the techno-organic virus and control infected beings