Air guns use compressed air to propel projectiles, unlike firearms using chemical propellants. First air guns developed in 16th century, oldest mechanical air gun from 1580. Modern air guns use spring-piston, pneumatic or compressed gas power sources
French Captain Minié invented the Minié ball in 1847. The rifle used a conical-cylindrical soft lead bullet with grease-filled grooves. The expanding gas pushed the bullet to engage rifling for better accuracy
Rifling creates helical grooves in firearms barrels for improved stability and accuracy. Twist rate measures distance for one revolution, expressed as ratio (e.g. 1:10 inches). Projectile length, weight, and shape determine required twist rate
Nuclear weapon yield measures energy released during detonation in kilotonnes or megatonnes. One terajoule equals 0.239 kilotonnes of TNT. One kilotonne of TNT is equivalent to 1012 calories
UK, Japan, and Italy launched a sixth-generation stealth fighter programme in December 2022. The programme aims to replace Eurofighter Typhoon and F-2 with a common fighter. A treaty was signed in December 2023 establishing the GIGO
Firearm muzzle velocities range from 120 to 1,700 m/s. NASA launches projectiles up to 8,500 m/s for spacecraft simulations. Velocity depends on firearm type, cartridge, and barrel length