gady-i-płazy: Projectile use by non-human organisms

Evidence: 100 • authority: 72

Although projectiles are commonly used in human conflict, projectile use by organisms other than humans is relatively rare. However, some organisms are capable of using various different types of projectiles for defense or predation. Some invertebrates are able to spit or squirt out fluids and some vertebrates also use liquid projectiles. Solid projectiles are used by various species. Tarantulas, for example, may kick off barbed hairs and several mammals have been observed to throw objects such as sand, rocks, sticks and feces. Chameleons, frogs and some salamanders have tongues that act like tethered projectiles. The pistol shrimp may emit a powerful wave of bubbles. Some plants produce se…

Evidence: 65 • authority: 72

Although several organisms are capable of rolling locomotion, no organisms are known to use true wheels or propellers to locomote, with the exception of the corkscrew-like flagella of many prokaryotes. Biologists have offered several explanations for the apparent absence of biological wheels, and wheeled creatures have appeared often in speculative fiction. Given the ubiquity of wheels in human technology, and the existence of biological analogues of many other technologies (such as wings and lenses), the lack of wheels in nature has seemed, to many scientists, to demand explanation—and the phenomenon is broadly explained by two factors: first, there are several developmental and evolutiona…

Evidence: 61 • authority: 72

Throwing () is a physical action that consists of mechanically accelerating a projectile and then releasing it into a ballistic trajectory, usually with the aim of impacting a distant target. Throwing typically refers to hand-throwing by animals with prehensile forelimbs, in which the projectile is grasped in a hand and the proximal limb segments move through compounded kinematic chains to impart a mechanically advantaged swinging motion. For other animals, the definition of throwing is somewhat unclear, as other actions such as spitting or spraying may or may not be included. Primates are the most prolific throwers in the animal kingdom, and they typically throw feces as a form of agonisti…

Evidence: 54 • authority: 72

A projectile is launched by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found in warfare and sports (for example, a thrown baseball, kicked football, fired bullet, shot arrow, a ball from a cannon, stone released from catapult, etc.). In ballistics, mathematical equations of motion are used to analyze projectile trajectories through launch, flight, and impact.

Evidence: 54 • authority: 92

Estimating the welfare impacts of differing projectile types utilised for stranded cetacean euthanasia.. Euthanasia may be necessary for stranded cetaceans to alleviate suffering, achievable through properly applied ballistics causing rapid insensibility and death. Despite widespread use, understanding of appropriate equipment relative to anatomical variation remains limited. We conducted experimental ballistics trials using cetacean cadavers to examine cranial trauma from five projectile types. A .308 calibre rifle with two deforming and three non-deforming projectiles was tested on 30 cadavers across four odontocete species (six per projectile type). Post-mortem computed tomography (PMCT)…

Evidence: 39 • authority: 80

Projectile Point Provisioning Strategies and Human Land Use

Evidence: 39 • authority: 72

Propulsion is the generation of force by any combination of pushing and/or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. A propulsion system is a machine system consisting of at least two core elements: the powerplant, a source of mechanical power; and the propulsor, an actuator mechanism that converts the supplied power into propulsive force; often also with supplementary components such as transmission and control system that enhance the final outcome of the propulsion system. Plucking a guitar string to induce a vibratory translation is technically a form of propulsion for the guitar s…