Here it has been discussed why the moon is moving away from earth at a rate of 1.5 inches per year. Is there any way we can estimate the value (e.g, 1.5 inches per year) mathematically?
Coastal and marine morphological zones Due to the incessant beating of the waves against the emergent lands, certain forms and landscapes typical of the zone of contact between the sea and the emerging land are created. This area is known by coast or coast. In general, the relief created is related to: a) The type of rock on the coast (cliffs or beaches), b) How currents and waves affect the coast: if directly, the water erodes and breaks (creating cliffs, gulfs and estuaries), if the rock is protected from the waves, accumulation of sediments occurs (the isthmus or tombstones, albufera and capes appear) c) The presence of rivers: if the river has less force than the waves, the sea will enter the river course (laugh, for example, the Galician), but if it is the opposite, the river will accumulate the materials transported in the sea (delta, for example that of the Ebro or that of the Nile).
Red sea, blue sea Who has not read news that speaks of seas whose waters are dyed the color of blood or that in the dark have begun to shine strange lights under the water hearing buzzing or strange noises? Is it science fiction or did they go crazy because of lack of water?
Mendel's laws and genetics Gregor Mendel was a modest Augustinian monk from the Abbey of Brno (or Brünn), who never imagined that he would go down in History as the father of Genetics. Concerned about improving the crops in the monastery garden, he decided to conduct an experiment. He took some seeds of a variety of pea that the monks cultivated in his garden.
DNA, the code of life Deoxyribonucleic acid or DNA is the molecule that contains the information of life. His discovery will go down in history as one of the great advances of the s. XX. Already in 1869 Friedrich Mieschen managed to isolate it from white blood cells, but never knew of its importance.
The visible face of the moon Why does the Moon always show us the same visible face? The gravitational attraction of the Moon on Earth brings up the level of the ocean on both sides of our planet and thus creates two bulges. As the Earth rotates from west to east, these two lumps (of which one always looks towards the Moon and the other in the opposite direction) travel from east to west around the Earth's surface.
Comets: The Oort Cloud The Oort cloud is a large concentration of comets subjected to the forces of the Sun and other stars. In the article The Oort Cloud, Paul R. Weissman, an expert in cometary dynamics, talks about these comets that orbit beyond Pluto. A fragment of this article is reproduced here in which the author begins by raising the question of the number of comets that form this immense cloud.
What is a black hole? To understand what a black hole is, let's start with a star like the Sun, which has a diameter of 1,390,000 kilometers and a mass 330,000 times greater than Earth's. Taking into account that mass and the distance from the surface to the center, it is shown that any object placed on the surface of the Sun would be subject to a gravitational attraction about 28 times greater than the Earth's gravity on the planet's surface.
The effect of the sea The main effect that the existence of seas and oceans on the earth's surface has on the planet is to act as a perfect climate regulator. During the day, the land (continent) tends to get hotter than the water, so it usually blows cold wind from the sea inland cooling the continental coastal areas by several degrees.
Sunspots If the temperature of the solar surface is so high that it is white, why are the sunspots black? To be black they would have to be cold, and how can there be something cold in the Sun? The question, as formulated, seems like a real catch. In fact, in the early nineteenth century the great astronomer William Herschel concluded that sunspots had to be cold because they were black.
Fermi paradox In the mid-50s, physicist Enrico Fermi posed a question to his colleagues: "Where are they?" Everyone understood that he was referring to other extraterrestrial civilizations. Your question continues today without an answer. Fermi's paradox is the contradiction between the high probability of not being alone in the Universe, and the absence of any trace of extraterrestrial life.
Habitable exoplanets Since March 2009, the Kepler space probe traces the sky in search of other habitable planets. For four years, you will observe more than 150,000 stars. Beyond our Solar System, billions of planets orbit around other stars. These planets are called extrasolars or exoplanets.
What are pulsars? In the summer of 1967, Anthony Hewish and his collaborators at the University of Cambridge detected, by accident, radio broadcasts in the skies that in no way resembled those that had been detected until then. They arrived on very regular impulses at intervals of only 1 1/3 seconds.
Drake's Equation In 1961, the president of SETI, Frank Drake, developed an equation to calculate the probability of contacting other civilizations of the Milky Way. It took into account astronomical, biological and technological factors. Its formula is: N = R * x Fp x Ne x Fl x Fi x Fc x L. R * is the number of stars that are born in our galaxy each year.
Biodiversity and extinctions After 4,000 million years of evolution, the most diverse life forms populate the Earth. A large number of animals, plants and other living things form the biodiversity of our planet. They live from the deep sea to the highest mountain ranges, tropical forests and arid deserts, even polar ice ... The existence of such different habitats is precisely the cause of the diversity of life forms on Earth is so wide and varied .
Is there life in other universes? So far, efforts to find life beyond Earth have not yielded any results. We may not be looking in the right way ... or in the right place. In recent decades, science poses a new possibility: can there be life in other universes?
Origin and evolution of the human being About 50,000 years ago, a group of men and women left Africa in search of food. They were some of the survivors of a raw glaciation. Today, 2,000 generations after that trip and with a world population of 7,000 million, it is hard to think that they are the common ancestors of all of us.
Theory of panspermia Could earth life be generated in outer space? The theory of panspermia raises the cosmic origin of life. The theory of panspermia recovers an old idea of the philosopher Anaxagoras, enunciated in ancient Greece of the s. VI a. C. But what is panspermia? The term comes from "bread" (everything) and "sperma" (seed).
Lunar seas Did you know that there are seas not only on Earth, but also on the Moon? And did you know that the seas of the terrestrial satellite are visible to the naked eye, from our planet? But, be careful: that our imagination does not play a trick on us by imagining large areas of salt water, agitated by large and numerous waves on the lunar surface.
Is there extraterrestrial life? How many places in the Universe have the appropriate conditions to house life? Is there extraterrestrial life? Or not? Let's see. If around half of the stars of our galaxy similar to the Sun orbit a planet, in the right place to have a temperature favorable to the appearance of life, then in the Milky Way there would be ten billion planets similar to the Land.