The Most Effective Martial Art for Self-Defence on the Street
As these populations grew more numerous, chronic warfare ensued as groups competed for the best soils and the prime spots along the river or mountain, and sought ways to recruit more members to their communities. In a world of hand-to-hand combat, having strong and numerous men to field was the top determinant of success in holding onto territory. Over time, some groups developed from single village communities into networks of communities, and chiefdoms emerged that provided some capacity to mobilize larger social units when any of their member communities was threatened. The evidence is quite substantial that, as human communities grew more successful in production, the temptation was great for other communities to take away their accumulated wealth (often in the form of grain or animals). As in the shift from HG to extensive cultivation, the shift from extensive cultivation to intensive cultivation appears to have been driven by population growth putting too much pressure on...
These huge swift creatures were the dominant carnivores of the continent for millions of years until competitors drove
The herd, stricken with fright, bolts in disarray as the predator bears down. The attacker fixes its attention on an old male lagging behind the fleeing animals and quickly gains on it. Although the old male runs desperately, the attacker is soon at its side. With a stunning sideswipe of its powerful left foot, it knocks the prey off balance, seizes it in its massive beak and, with swinging motions of its head, beats it on the ground until it is unconscious. Now the attacker can swallow the limp body whole an easy feat, given the creature's meter-long head and half-meter gape. Content, the gorged predator returns to its round nest of twigs in the grass nearby and resumes the incubation of two eggs the size of basketballs.
Meteorologists focused on the whys behind the weather at the same time they worked to improve weather forecasts. Advances in aeronautics provided opportunities to gather data at higher altitudes and put pressure on meteorologists to develop upper-level forecasts critical for flight safety. Mid-decade, as war spread across Europe, accurate weather data and forecasts became vitally important to soldiers on the ground and in the air as new war fighting techniques required carefully tailored forecasts. Scientific investigations on climate change continued also, with the emphasis shifting from anthropogenic carbon dioxide to solar variations. These new efforts encouraged the adoption of mathematically rigorous scientific tools as proposed and promoted by Vilhelm Bjerknes.
Nuclear power plants have two vulnerable components the reactors themselves and the spent fuel that is stored on-site, near the reactor. The example of September 11, 2001 raises the spectre of an airplane crash into a nuclear power plant. The containment structure enclosing the plant is designed to withstand the impact of a small plane but, in most cases, not that of a large airliner. However, even if an airliner could be hijacked, a nuclear power plant is relatively difficult to hit directly because of its low height and small target area. The potential results of such an impact are being studied, but the results are classified 25, p. 42 . Nonetheless, it is likely that they would vary widely, depending on the precise point of the impact and the unpredictable good fortune the attacker might have in disabling the cooling system and breaching the reactor vessel.
Game theorist Robert Axelrod used computer simulations to compare sixty-two different strategies for cooperation and defection between pairs of players matched in a cyberspace tournament. With a change of terminology, cooperation can be viewed as somewhat analogous to engaging in restrained, relatively safe fighting, whereas defection can be seen as employing injurious fighting techniques. Interestingly, one strategy, called tit for tat, outperformed all the other strategies. The tit for tat strategy entails always cooperating on the first move and thereafter doing exactly what the other player did on the previous move. If the other player defects rather than cooperates, tit for tat also defects next time. If the other player then cooperates, the tit for tat strategy then also cooperates. Thus the tit for tat approach parallels in some ways the retaliator strategy from the hawk-dove simulations, which never attacks (defects) first, but responds to an attack (defection) by fighting...
For the Montagnais-Naskapi, Netsilik, and Ju 'hoansi. However, not all homicides are avenged.7 It is important to emphasize a recurring pattern among nomadic foragers When revenge is undertaken, the tendency is for family members of the victim to target the killer personally. This pattern is apparent in Ju 'hoansi homicide data. Recall that eleven out of a total of twenty-two killings were initial homicides.8 Subsequently, revenge was sought against four original killers, whereas seven killings went unavenged. During retaliation attempts, the attacks sometimes went awry, resulting in the death of an attacker or a bystander rather than (or in addition to) the original malefactor. A cross-cultural study of vengeance by Karen Ericksen and Heather Horton also reflects the pattern among nomadic foragers wherein individuals, as opposed to kin groups, engage in self-redress against killers. In a majority of the nomadic band societies (eleven of seventeen) for which information was available,...
Photophores are often arranged in highly distinctive patterns which differ between closely related species and between the sexes, probably providing a means of recognition and facilitating shoaling. Some creatures can flash their lights on and off, and this may serve to confuse, alarm or dazzle attackers, or in some cases may even attract the attackers' own enemies. Luminous clouds squirted into the water, such as the luminous ink of the squid Heteroteuthis, and some worms, are presumably a means of defence, perhaps by dazzling or possibly by making attacking creatures themselves visible to their own predators. In some cases the attacker becomes coated in sticky luminous material.
Observation and experiment show that predators are often more successful in capturing prey which have become separated from a shoal than from the shoal itself. Individual prey are easily pursued and taken whereas the presence of a shoal lessens the efficiency of capture. The attacker is distracted, first one and then another target is chased thus energy is wasted and time given for the prey to recover from pursuit. A shoal also possesses innumerable watchful eyes to detect the approach of a predator, with possibilities of imitation or communication within the shoal leading to evading action (Shaw, 1962).