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:
“My vocabulary dwells deep in my mind and needs paper to wriggle out into the physical zone. Spontaneous eloquence seems to me a miracle. I have rewritten—often several times—every word I have ever published. My pencils outlast their erasers.”
—Vladimir Nabokov (1899–1977)
“There are two barriers that often prevent communication between the young and their elders. The first is middle-aged forgetfulness of the fact that they themselves are no longer young. The second is youthful ignorance of the fact that the middle aged are still alive.”
—Jessamyn West (1902–1984)