Most natural resources are limited. This means they will eventually run out. A perpetual resource has a never-ending supply. Some examples of perpetual resources include solar energy, tidal energy, and wind energy. There may be a limit to how much can be taken in a given day or year, but that amount can be taken again next day or next year.
Non perpetual resources include Fossil fuels such as Petroleum,coal ,etc. They have a limit of usage.
Some of the things influencing supply of resources include whether it is able to be recycled, and the availability of suitable substitutes for the material. Non-renewable resources cannot be recycled. For example, fossil fuels cannot be recycled.
The demand for resources can change with new technology, new needs, and new economics (e.g. changes in cost of the resources). Some material can go completely out of use, if people do not want it any more. Demand of many natural resources is very high, but availability of some, such as precious metals, is very low.
Different places have different natural resources. When people do not have a certain resource they need, they can either replace it with another resource, or trade with another country to get the resource. People have sometimes fought to have them (for example, spices, water, arable farmland, gold, or petroleum).
When people do not have some resources, their quality of life can get lower. So, people protect resources. When they can not get clean water, people may become ill; if there is not enough wood, trees will be cut and the forest will disappear over time (deforestation); if there are not enough fish in a sea, people can die of starvation. Renewable resources include crops, wind, hydroelectric power, fish, and sunlight. Many people carefully save their natural resources so that others can use them in future.
Negentropy
Negentropy is reverse entropy. It means things becoming more in order. By 'order' is meant organisation, structure and function: the opposite of randomness or chaos. One example of negentropy is a star system such as the Solar System. Another example is life.
As a general rule, everything in the universe tends towards entropy. Star systems eventually become dead. All energy has gone, and everything in the system is "at the temperature of the surrounding space". The opposite of entropy is negentropy. It is a temporary condition in which certain things are hotter and more highly organised than the surrounding space. This is the second law of thermodynamics:
Life is considered to be negentropic because it converts things which have less order, such as food, into things with more order, such as cells in the body, tissues, and organs. In doing so, it gives off heat. Another example of negentropic things are societies, or social systems, because they take disorderly things such as communications, and make them more orderly and useful.
North America
North America is a large continent in the Northern and Western Hemispheres of Earth. It is to the east of the Pacific Ocean, the west of the Atlantic Ocean, the south of the Arctic Ocean, and it is the northern part of the Americas. The southernmost part is Central America. It is the third largest continent in the world, after Asia and Africa. North America has a population of around 371 million and is the 4th most populous continent in the world.
Hundreds of millions of years ago, North America was part of a larger ancient supercontinent named Laurasia. A few million years ago, a new land bridge arose and connected North America to South America. Beringia connected North America to Siberia a few times during ice ages in the past 20,000 years. North America has lots of hot and nice tropical islands such as the Bahamas. North America is currently north of South America.
Neptune
Neptune is the eighth and last planet from the Sun in the Solar System. It is an ice giant. It is the fourth largest planet and third heaviest. Neptune has five rings which are hard to see from the Earth. It is seventeen times heavier than Earth and is a little bit heavier than Uranus. It was named after the Roman God of the Sea.
Neptune's atmosphere is mostly made up of hydrogen and helium. It also contains small amounts of methane which makes the planet appear blue. Neptune's blue color is much darker compared to the color of Uranus. This planet also has the strongest winds of any planet in the Solar System, measured as high as 2,100 km/h or 1,300 mph.
Neptune was discovered by the astronomers Urbain Le Verrier and John Couch Adams. They were both honored for the discovery. The planet was the first to be discovered by mathematical calculations instead of using a telescope. In 1821, it was found that Uranus' orbit had some differences from its expected orbit. So astronomers searched for another new planet.
The planet was visited by only one spacecraft, "Voyager 2" on 25 August 1989. Neptune once had a huge storm known as the "Great Dark Spot" which was discovered in 1989 by Voyager 2. However, the dark spot was not seen in 1994, and new spots were found since then. It is not known why the dark spot disappeared. Visits by more space probes have been proposed.
The first possible sighting of Neptune is thought to be by Galileo as his drawings showed Neptune near Jupiter. But Galileo was not credited for the discovery since he thought Neptune was a "fixed star" instead of a planet. Because of Neptune's slow movement across the sky, Galileo's small telescope was not strong enough to detect Neptune as a planet.
In 1821, Alexis Bouvard published the astronomical tables of the orbit of Uranus. Later observations showed that Uranus was moving in an irregular way in its orbit. Therefore some astronomers thought of another large body. In 1843, John Couch Adams calculated the orbit of an eighth planet that would possibly be influencing the orbit of Uranus. He sent his calculations to Sir George Airy, the Astronomer Royal, who asked Adams for an explanation. In 1846, Urbain Le Verrier, who was not working with Adams, made his own calculations but also failed to get much attention from French astronomers. However, in the same year, John Herschel began to support the mathematical method and encouraged James Challis to search for the planet. After much delay, Challis began his unwilling search in July 1846. Meanwhile, Le Verrier had convinced Johann Gottfried Galle to search for the planet.
Heinrich d'Arrest, a student at the Berlin Observatory, suggested the following. A newly drawn map of the sky in the region of Le Verrier's predicted area could be compared with the current sky. It was needed to look for the change of position of a planet, compared to a fixed star. Neptune was then discovered that very night on 23 September 1846, within 1° (one degree (angle)) of where Le Verrier had predicted it to be, and about 10° from Adams' prediction. Challis later found out that he had seen the planet twice in August, failing to recognize it due to his careless work approach.
When Neptune was discovered, there was also a lot of arguing between the French and the British. It was about who was to deserve credit for the discovery. Later, an international agreement decided that both Le Verrier and Adams together deserved credit. However, historians reviewed the topic after the rediscovery in 1998 of the "Neptune papers" (historical documents from the Royal Greenwich Observatory). It had seemingly been stolen and kept by astronomer Olin Eggen for nearly three decades and was only rediscovered (in his ownership) shortly after his death. After reviewing the documents, some historians now think that Adams does not deserve equal credit with Le Verrier.