A stele is a memorial monument made of stone.
Estela is a term that can have various etymological origins. When it comes from the Latin stela (which, in turn, derives from Greek), it is a commemorative monument that stands above the ground as a pedestal, tombstone or cippus.
On the stele, some ancient people used to inscribe symbols , signs , figures or texts that explained the reason for the construction. The usual thing is that the stelae are monolithic and made of stone materials.
The Stele of Mesha (also known as the Moabite Stone ), the Stele of Merenptah ( Stele of Victory ) and the Cantabrian stelae are some examples of this type of monuments. It should be noted that the tombstones that are still used today, where the name of the deceased and the dates of his birth and death are recorded, can be considered within the set of commemorative steles.
The stele as a trail
From the Latin aestuaria , wake is the trace , sign or footprint left by something that passes by. It may be a trace in water, air or another medium.
For example: “The wake left by the plane could be seen from several kilometers away,” “The boat left, in its wake, a trail of foam that amused the little passengers,” “A trail of vapor came out of the jug that “It caught the researcher's attention.”
Airplanes generate a wake when moving.
A trace of condensation
The trail that a body leaves in the air when it moves is called a condensation trail . In the case of airplanes, the contrail is usually called steam and is generated at the rear of the turbine exhausts. Its appearance is similar to that of cirrus clouds (a type of cloud that is made up of ice crystals and has a fine, thin shape).
Contrail also appears in vortices left by jet wings, which send a frozen stream of crystals into the atmosphere . It is worth mentioning that, despite what it may seem, the wake does not cause pollution to the environment. The reason for its appearance is a low level of pressure at a considerable altitude.
On the other hand, airplanes also generate another type of contrail, which appears at the end of each wing and dissipates very quickly. This is nothing other than condensed vapor and arises due to the difference in pressure that exists between the top and bottom of the wing, which generates a current of air similar to a whirlwind, and this can gain enough strength to produce a vacuum and cause the air temperature to drop in a short time.
Regarding its impact on the climate , contrail can negatively impact cloud formation, as a radiative forcing (a change in radiation entering or leaving a climate system). In more than one study it has been proven that the contrail captures the long-wave radiation emitted by the Earth and the atmosphere at a higher rate than the radiation from the sun. In other words, the wake contributes to global warming.
This effect varies every day and the magnitude of the changes in incoming and outgoing radiation is not known precisely. In the United States , a country with considerable air traffic, contrail has been proven to reduce the sun's heat during the day and heat radiation at night, due to increasing albedo (the percentage of radiation that reflects a surface with respect to the one that impinges on it).
Estela as a female name
Estela is also a feminine name that is used in several countries.
Personalities such as Estela de Carlotto (president of the Abuelas de Plaza de Mayo Association ), the singer Estela Raval and the former Argentine president María Estela Martínez de Perón share this name.