How do waves generate electricity?

 The waves have long been used to generate energy. In the 18th century, several plants were built on Europe's coasts where the waves reached a reservoir with floodgates. These were closed when the tide was high; once it came down, the water could only escape from the reservoir by passing through a hydraulic turbine that turned to generate energy.

The same principle was applied to a power plant built in France in the 1960s. A dam was built in the estuary of the Rance River, Brittany region, with 24 machines that can function as turbines, regardless of whether the water flows in one direction or the other.

When the tide comes in, water accumulates against the dam until there is a 1.5 metre difference between the two sides. It is then passed through the electricity-generating turbines. As the tide goes down, the turbine blades turn and the water that returns to the sea generates electricity again.

The amount of electricity produced depends on the water level on both sides of the dam. The greater the difference in level, the more electricity is generated, because the water is under greater pressure and turns the turbines with greater force.

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How does a nuclear reactor generate electricity?

A handful of uranium provides as much electricity as 70 tons of coal or 30 barrels of oil. A nuclear reactor to power a city of one million people consumes only 3 kg of uranium per day, making it the most concentrated energy source used by man.

Uranium is one of the densest natural elements and its atoms are very unstable. The nucleus of the atom only needs a small "push" to disintegrate, and when this happens it releases large amounts of energy, in the so-called nuclear fission.

This "push" can be received from neutrons, particles much smaller than atoms, which collide with the nucleus and disintegrate it. During this process at least two more neutrons are produced, which detach from the atom and then cause other fissures, so that these can continue indefinitely.

The energy of fission can be released little by little, and used to heat water. The water vapour is used to activate an electricity generator.

This is how a nuclear reactor works.

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What were some characteristics of Mayan culture?

 The Mayan civilization established an intellectual superiority over other Indo-American cultures. This was manifested in their language and writing, in their conception of the cosmos and in their mathematical knowledge.

The system of temporal registration, which he shared with other Mesoamerican groups, constitutes an important instrument of historical and astronomical registration. Lately it has been discovered that the inscriptions that make up the calendar are more secular than was believed, since they also contain data on births, ascents, marriages and military victories of the reigning dynasties. Until now, the meaning of the signs outside the temporal register is unknown, but it is known that the classical language of the inscriptions is different from the Mayan language that was used when the Spanish conquest, six centuries after the fall of the classical period. The writing belonging to this period is idiographic and has 300 to 500 figures, the number depends on how the affixes are separated from the so-called main signs, so it will still be some time before specialists can decipher them all.

In mathematics they had achievements that surpassed with much to the one of the zero and the positional numeration. In astronomy they calculated with great accuracy the solar year which they divided into 18 months of 20 days each, they also had a sacred year, tzolkin, through which the priests detected the good and bad influences of each day according to an esoteric meaning of numbers and sign days, and a series of cycles: uinal of 20 days, tun of 360, katun of 7,200, bactun of 144,000 and alautun of 12,040,000,000. The Dresden codex contains very precise lunar and venusian tables, as well as a method for predicting solar eclipses.

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Things you didn't know about the pyramids in Egypt

 If the Great Pyramid were to be broken into 30 cm thick slabs, a one metre high wall could be built around France.

Some have said that the pyramids were more than gigantic sepulchres; they could also have been granaries or treasure houses.

All the pyramids were probably looted a few centuries after they were built; the only tombs that escaped spoil were those built on the rock outside the pyramids, such as that of Tutankamon and Queen Hetepheres I. 

The Egyptians apart from mummifying the pharaohs, also did so with their pets, and buried them with their masters inside the pyramids.

The weight of the Great Pyramid is approximately 5,400,000 tons. The largest known stone is found in the pyramid of Micerino, which weighs about 285 tons - 200 to 250 cars.

The Great Pyramid was built by the Pharaoh Jufu of the Fourth Dynasty.

The Great Pyramid is Egypt's biggest tourist attraction.

It is the only one of the seven ancient wonders still standing.

The Greek Herodotus wrote that it took the Egyptians 20 years to build the Great Pyramid.

Herodotus also mentions that another 10 years, before the construction of the pyramid, was used to prepare the ground and build the underground chambers.


These are the names of the three main pyramids in Egypt:

• Pyramid of Jufu (Keops), or Great Pyramid in Giza
• Pyramid of Jafra (Kefren) in Giza
• Pyramid of Menkaura (Micerino) in Giza

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How do flowers attract insects?

 Some plants know how to attract nectar-seeking insects. For this they use chemical compounds that excite their sensitive vision to ultraviolet radiation.

In addition, the same substances repel other insects that try to feed on them, such as caterpillars. Even before the flower bud opens, it is covered with these substances called DIP, which have been discovered by a team of entomologists at Cornell University in the United States. The pigments dye the flower with a color invisible to the human eye, but perceptible to the ultraviolet vision of some pollinating insects, such as bees.

Researchers have found these pigments in Hypericum calycinum, a Southeastern European plant with uniform yellow flowers. For insects with ultraviolet-sensitive eyes, however, what stands out is a darker central point, towards which they will head without hesitation.

Now, experts are studying whether the visual patterns displayed could also help insects recognize one flower among many others.

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Did you know that sheep are excellent physiognomists?

Sheep, unfairly branded as not very intelligent, have in the researchers of the Babraham Institute of the University of Cambridge the fierce defenders of a quality ignored until now: their physiognomistic insight.

According to Nature, these animals can distinguish known congeners from 50 other sheep. It seems that the temporal and frontal lobe cells of these sheep are activated when they see the face of a sheep that is familiar to them, just as one person recognizes another.

For Keith Kendrick, director of the project, "this indicates that the sheep may miss fellow flock members who are no longer with them.

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Great facts about King Henry VIII of England

INTERESTING FACTS ABOUT KING HENRY VIII

The king of England, Henry VIII, fearful of getting black plague, spent most summers outside London to avoid the plague.

When Henry VIII did something wrong as a child, another child took his place and was punished.

Henry VIII had an amazing memory and could remember the name of every servant in the Royal House.

At the time of death Henry VIII possessed 50 palaces, a royal mark for England.

Henry VIII died with immense debts.

Henry VIII was married to Catherine of Aragon for 20 years.

King Henry VIII was the creator of some musical compositions.

At the time of Henry VIII's death he had a waist of 135 cm.

Henry VIII liked to self-medicate and some medical treatments for ulcers he himself had created.
The English monarch married six times.

Elizabeth I of England was the daughter of Henry VIII and Anne Boleyn.

Anne Boleyn, Henry VIII's second wife, was accused of adultery and beheaded on 19 May 1536.

Henry VIII's reign lasted from 1509 to 1547.


Henry VIII composed short works among which can be cited:

Pastime With Good Company
Though that men do call
Though some saith
If Love now reigned
Depàrture is my chief pain
Adieu madame et maitresse

How do snakes produce their venom?

How Snakes Develop Venom Inside Their Body

An analysis of twenty-four different toxins indicates that when the snakes developed the poison, they used proteins from all over their body. Surprisingly, they transform harmless proteins into lethal venom.

This enigma attracted the attention of Bryan Fry, of the Australian Poison Research Unit at the University of Melbourne in Parkville, Victoria, who did a genetic analysis of 24 types of snake toxins.

As part of the research, Fry compared the amino acid sequences of toxins with those of proteins in the brain, heart, liver, and other organs. Thus, he determined that 21 of the 24 poison proteins appeared to be linked to proteins from those parts of the body.

That underscores the tremendous diversity of toxins in snake venom," explains Wolgang Wuster of the University of Wales in Bangor, "and demonstrates that they come from the full range of organs in the animal.

Fry believes that a thorough examination of the molecular composition of toxins could help drug manufacturers work in reverse to understand how normal proteins work.

For now, he continues his research to understand how the snake venom glands started using proteins.

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Facts about okapis

 The okapi (Okapia johnstoni) is a mammal belonging to the same family as the giraffes.

Because of the zebra-like stripes on its legs and buttocks, it is often confused with this animal.

The okapis are solitary creatures, that gather only to mate. The only groups are those of the mother and her calf.

The okapis live deep in the Congo jungle.

The okapis mark their territory either with an oily substance from their own legs or by urinating.

This species lives in altitudes of 500 to 1000 m, although they can venture to higher altitudes in the mountainous forests of the east.

The diet of an okapi includes tree leaves, grass, ferns, fruits and mushrooms.

The existence of the okapi was first confirmed in Congo in 1901.

The okapis have a long tongue, which they use mainly to pull leaves from trees. They also use it to clean their eyelids and even to... the ears!

Okapis are ruminant animals, which means they regurgitate what they eat, chew it again and swallow it again.

Like giraffes, okapis have small horns covered with skin.

The only time a female okapi vocalizes is when it is in breeding season.

The young of an okapi defecates for the first time between 4 and 8 weeks of birth.

The leopard is the only predator of the okapis.

An okapi can live from 30 to 33 years.

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Great facts about the Statue of Liberty

The face of the Statue of Liberty is said to have been modelled on that of the sculptor's mother - Frédéric Auguste Bartholdi.

This colossal statue was inspired by the classical sculptures of Greece and Rome.

The Statue of Liberty was a gift from France to the United States in 1886.

The crown of the statue has 25 windows and 7 peaks.

The peaks of the crown are thought to represent the seven continents as well as the seven oceans of the world. However, the peaks are actually rays of sunshine and the circle is a halo or what in art is called a "nimbus".

The weight of the Statue of Liberty is 31 tons of copper, 125 tons of steel and 27,000 tons of concrete.

The statue's torch has been closed to the public since 1916.

When the wind exceeds 80 km per hour, the statue is tilted about 8 cm, while the torch is tilted about 12 cm.

In the Statue of Liberty there have been at least three suicides over the years.

Since the beginning of cinematography, the Statue of Liberty has been used as the setting for a multitude of films. One of those films in which it appeared was Charles Chaplin's 1917 film, The Immigrant.

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What is geothermal energy?

What is geothermal energy used for?

 Geothermal energy comes from the heat of the Earth's depths. About 30 kilometers below the surface is a layer known as the earth's mantle. This is the source of the gas and lava that erupts from volcanoes. Springs and geysers, with temperatures above 250 degrees Celsius, are also heated by the mantle.

Because of its high temperature, the mantle is a promising source of energy, especially in areas where hot water is very close to the surface.

Iceland, a country that has a large number of volcanoes and springs, makes efficient use of this energy resource, about 85% of houses use it.

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What are stigmas in the body?

What kind of people carry stigmas?

Padre Pio with stigmas

According to the history of Christianity, the stigmata are the marks left by the cross in the body of Christ.

According to the Catholic religion characters such as St. Francis of Assisi and St. Gemma Galgani (among other 60 saints and blessed) present these marks.

However, Catholicism recognizes that stigmas can appear in any person, as long as they have certain traits such as resistance to infections and physical and emotional pain, among others.

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Who was Lilith?

What is the origin of Lilith?

 The name Lilith means "night monster." It is a female demon that appears in Hebrew folklore. Its name and legend derive from a very ancient tradition of Assyria and Babylon, where there was a very similar demon called Lilit or Lilu.

Part of rabbinical literature says that she was the mother of the diabolical son that Adam had after separating from Eve.

The cult of Lilith remained active for many years. In the 7th century A.D. it still survived in certain Jewish groups. Today it symbolizes the destructive force of the feminine, but also its irreverence and rebellion.

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What's the biggest flower in the world?

Where does the biggest flower grow?

It is undoubtedly Amorphophallus titanum, which is the flower with the largest known size.

It is native to Indonesia, although it was at the University of Bonn, Germany, that in 2003 the largest living specimen so far emerged: 2.74 m high.

Its flowering occurs only three or four times in the forty years that the plant usually lives. The bud grows 10 cm per day, reaching almost 2.5 m in height, one meter in diameter and a weight of approximately 75 kilos.

The flower can only live for three days.

Amorphophallus titanum, the biggest flower in the world

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Where were the first skyscrapers built?

What are skyscrapers?

 Skyscrapers were born in the United States. Although several high-rise buildings had already been built by the end of the 19th century, the first skyscraper itself was the Home Insurance Building built in 1899, which was 30 stories high.

In the early decades of the twentieth century, nine of the ten tallest buildings were built in that country. The tenth was in Toronto, Canada.

Today there are only two in the U.S. (the Sears Tower in Chicago and the Empire State Building in New York), while the other eight rise in Asia. U.S. developers are not encouraged to build so high because of the economy and the terrorist attacks of September 11.

Even before this date, in Western countries, skyscrapers had lost their symbol as a parameter of wealth, power and importance, unlike the rest of the world where they still retain that status.

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What does poltergeist mean?

How is a poltergeist produced?

Poltergeist is a paranormal phenomenon whose term derives from the German words polter (noise) and geist (spirit), so it literally means noisy spirit.

Parapsychology scientifically calls it recurrent spontaneous Psychokinesis and defines it as an ultraphysical manifestation that does not respond to an apparent cause. The poltergeist phenomenon is classified as follows:

• Acoustic. Blows, human or chanting sounds.
• Dynamic. Levitating horizontal movements.
• Optical. Flashes or luminous spheres that move and shadows or translucent bodies.
• Tactile. From the sensation of rubbing to aggression.
• Smells. Hedores or perfumes.
• Others. Spontaneous combustion, thermal or electromagnetic alterations.

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What is the legend of the Buddha's birth?

 Who was the Buddha?

Buddhism is one of the most important religions in the world; and a curiosity about it is that its followers believe that the founder's conception occurred when his mother dreamed that a celestial elephant with six tusks came down to her, and entered from the side of her belly.

Then, according to the same legend, the exact birth of Siddhartha occurred when his mother walked through Lumbini's garden and looked up at Heaven. At birth the child took seven steps in each direction from Heaven, growing a lotus flower at each step he took; then he prophesied that he would not be born again (this because Buddhists, as in the Brahmanic religion, believe in reincarnation).

Then, in a vision, the father of the young prince was told that he would be a mighty king walking in time, or instead, a man of holiness (the Buddha).

The father, fearing for his succession, removed the child from all that was religion or from knowing what human suffering was, depriving him of the outside world; he hoped that his son, Gautama Siddharta, would become the great king of whom the vision spoke.

However, the fate of the child was already marked as the future Buddha.

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What were Julius Caesar's last words?

 How did Julius Caesar die?

 "Even you, my son?" are the words, according to Suetonius, who spoke Julius Caesar to his protégé Brutus, when he and other senators assassinated him in the Curia Pompeii.

Mark June Brutus was unhappy with Julius Caesar because of some measures he had implemented in Rome, which increased his power as a dictator.

Brutus' brother-in-law, Gaius Cassius Longinus and some senators also took part in the conspiracy.

Not everything went well for the murderers, as Rome held Julius Caesar in high esteem, so they had to flee to the East.

Some time later, in the Battle of Philippi, Brutus committed suicide to avoid being captured by the armies of Octavian and Mark Antony.

What is air conditioning? How does A/C work?

Facts about A/C for kids

In winter, houses are heated with stoves or radiators. On the other hand, in summer, the interior temperature of a house can be produced by means of an air conditioning system.

Air conditioning consists of giving it the desired purity, temperature and hygrometric degree. In excessively hot or cold climates, air conditioning installations are indispensable. They allow life and activity to be normal, despite the rigours of the outside temperature. Air cooling is obtained by projecting air from special refrigeration systems inside the premises. In public places (showrooms, department stores, hotels, etc.), air conditioning provides users and customers with an undeniable sense of comfort.

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What are detergents? How do detergents work?

Interesting detergent facts for kids

You can't always remove stains from dirty objects by washing them with water. It is often necessary to add to this water a special product that penetrates the stains and makes them disappear: it is the detergent.

The most common detergents are soaps, whose essential property is to break up insoluble grease stains into tiny particles, which disperse in the water: soaps emulsify grease. Modern detergents include a number of petroleum by-products in the form of white granules, sometimes perfumed and usually impregnated with a fluorescent product that gives dry linen a special shine. Detergents should not be confused with solvents used in dry cleaning.