crack

Crack has several senses. In everyday use, a crack is a line or fracture along which a solid has split or opened. As a verb, to crack means to break or cause to break, often producing a sharp sound. In drug contexts, "crack" most commonly refers to crack cocaine, a freebase form of cocaine that is crystallized and typically smoked.

In engineering and materials science, a crack is a flaw or separation within a solid caused by stress. Cracks can propagate when the material is loaded; their growth depends on factors such as stress intensity, toughness, and environment, and can lead to sudden failure if unchecked. Detection methods include visual inspection, dye penetrant testing, ultrasonography, and X-ray imaging. Mitigation involves design changes, material selection, protective coatings, and controlled loading.

In geology, cracks in rocks form joints and faults, often from cooling, dehydration, or tectonic forces. Cracks influence rock strength, fluid flow, and landscape evolution, and their networks can help scientists understand past stresses.

Crack cocaine is a form of cocaine that is processed into small, rapidly smoked crystals. Smoking crack produces fast, intense effects followed by a short duration, contributing to a high risk of dependence and acute health problems, such as cardiovascular stress and respiratory issues. Use is illegal in most places and associated with social harms and legal penalties.

Public health responses emphasize education, prevention, treatment, and harm-reduction strategies. Evidence-based addiction treatment, counseling, and social services are used to reduce harms associated with crack use. Legal and policy approaches vary, with ongoing debates about balancing enforcement with health-focused interventions.