Physical Barriers
As physical obstacles, we can enumerate all those physical barriers that block the action and prevent the progress or the achievement of a concrete goal. Examples:
- architectural barriers that hinder access to people with reduced mobility;
- doors, gates, and access control systems, designed to keep intruders or attackers out;
- large objects, fallen trees or collapses through passageways, paths, roads, railroads, waterways or airfields, preventing mobility;
- sandbanks, rocks or coral reefs, preventing free navigation;
- hills, mountains and weather phenomena preventing the free traffic of aircraft;
- meteors, meteorites, micrometeorites, cosmic dust, comets, space debris, strong electromagnetic radiation or gravitational field, preventing a spacecraft from navigating freely in space.
Read more about this topic: Obstacle
Famous quotes containing the words physical and/or barriers:
“Unfortunately, moral beauty in art—like physical beauty in a person—is extremely perishable. It is nowhere so durable as artistic or intellectual beauty. Moral beauty has a tendency to decay very rapidly into sententiousness or untimeliness.”
—Susan Sontag (b. 1933)
“... in love, barriers cannot be destroyed from the outside by the one to whom the cause despair, no matter what he does; and it is only when he is no longer concerned with them that, suddenly, as a result of work coming from elsewhere, accomplished within the one who did not love him, these barriers, formerly attacked without success, fall futilely.”
—Marcel Proust (1871–1922)