Inca Rope bridge

Inca Rope bridges were simple suspension bridges over canyons and gorges to present access for the Inca Empire. Bridges of this type were suitable for use since the Inca people did not use wheeled transport - traffic was incomplete to pedestrians and livestock. These bridges were an intrinsic part on the Inca road scheme and are an excellent example of Inca innovation in engineering. They were frequently used by Chasqui runners delivering messages throughout the Inca Empire.
The construction of these bridges amounted to a pair of stone anchors on each side of the canyon with immense cables of woven ichu grass linking these two pylons together. Adding to this construction, two additional cables acted as guardrails. The cables which supported the foot-path were unbreakable with plaited branches. This multi-structure system made these bridges strong enough to even carry the Spaniards while riding horses after they indoors. However, these massive bridges were so heavy that they tended to sag in the middle, and this caused them to bend in high winds.

Planet

A planet, as defined by the International Astronomical Union (IAU), is a celestial body orbiting a star or stellar remains that is massive enough to be rounded by its own gravity, not massive enough to cause thermonuclear fusion in its core, and has cleared its neighboring region of planetesimals. The term planet changed from something that stimulated across the sky, to a body that orbited the Earth. When the heliocentric model gained sway in the 16th century, it became established that a planet was actually something that directly orbited the Sun. At the end of the 17th century, when the first satellites of Saturn were exposed, the terms planet and satellite were at first used interchangeably, although satellite would gradually become more common in the following century.

The energetic impacts of the smaller planetesimals will heat up the increasing planet, causing it to at least partially melt. The interior of the planet begins to differentiate by mass, mounting a denser core. Smaller terrestrial planets lose most of their atmospheres because of this accretion, but the lost gases can be replaced by out gassing from the mantle and from the succeeding impact of comets.

Populations

Populations are studied, in exacting, in a branch of ecology known as population biology, and in population genetics. In population dynamics, size, age and sex structure, mortality, reproductive behavior, and development of a population are studied. In biology, an isolated population denotes a breeding group whose members breed mostly or solely among themselves, usually as a result of physical isolation, although biologically they could breed with any members of the varieties. If there are several completely or nearly completely secluded populations in the global population of a taxon, these are called subpopulations. The Metapopulation is a network of subpopulations in a given area, where the individuals of the various subpopulations are able to cross dilapidated areas of the region. Biological dispersal is one of the key elements upsetting such populations; if dispersal is sufficiently low for a prolonged period of time, speciation is likely to be a consequence.

Population growth is varying in population over time. It also can be quantified as the change in the number of individuals in a population per piece time. The term population growth can technically refer to any species, but almost always refers to humans, and it often used easily for the more specific demographic term population growth rate, and is often used to refer specifically to the expansion of the population of the world.