A pretender is someone who says that he or she has the right to be ruler. The word is often used to describe someone who claims that they have the right to be king, queen, emperor etc. They claim that the ruler who is on the throne should not be there.
Sometimes people call such a person a "claimant". The person may be an imposter (someone who is pretending to be someone else). Often they are pretending to be a prince or other royal person who is missing or whom people think is dead. However, they may have a genuine right to the throne. The word "pretend" comes from the French word "prétendre" (from the Latin "praetendo" lit. "to stretch out before"). It means: to profess, to make a loud statement. In modern English the word "pretend" means "to claim falsely".
Native American mythology
Native American mythology is the body of traditional stories associated with Native American religion.
Low Earth orbit
A low Earth orbit (LEO) is usually described as an orbit inside the area which comes from the Earth’s surface up to an altitude of . Other definitions use other numbers such as orbital eccentricity and orbital period. Satellites in LEO go around the Earth many times per day.
Satellites are put in low Earth orbit if the things they do must be done in outer space but need not be far away. Some satellites are in LEO to photograph the Earth, for example some weather satellites and Earth resource satellites. Most space telescopes are in LEO since they only have to be above the Earth's atmosphere. The International Space Station is in LEO.
Bornu Empire
The Bornu Empire (1380-1893) was an African state of Nigeria from 1380 to 1893.
Tōtōmi Province
The province had borders with Mikawa, Suruga and Shinano Provinces.
Tōtōmi was one of the original provinces of Japan established in the Nara period under the Taihō Code.
In the Edo period, the Tōkaidō road was the main route between Kyoto and Edo. The road passed through Tōtōmi.
In the Meiji period, the provinces of Japan were converted into prefectures. The maps of Japan and Izu Province were reformed in the 1870s.
"Oguni jinja" and "Kotonomamahachimangū" were the chief Shinto shrines ("ichinomiya") of Tōtōmi.
Altitude
"Altitude" means height above the ground or above the sea level. Common uses include aviation (flying, parachuting, gliding), and geography/surveying. In geometry it is also used as the height of the object itself. Generally, altitude is the distance one thing is above another thing. This is in the vertical or "up" direction. For the height of the ground (such as for hills and mountains), the word elevation is also used and might be a better choice. (Mountain climbers usually use the word altitude, especially when talking about how it affects the body). Buildings and other things on the ground usually just use the word height.
Vertical distance measurements in the "down" direction are commonly referred to as depth.
In aviation, the altitude can be measured and shown in several different ways. The height is either from the average sea level (also called "Mean Sea Level" or MSL), or from the ground (also called "Above Ground Level", or AGL).
Airplanes can find their altitude by using air pressure. The air gets thinner the higher it is (and it has less pressure, because there's less air pushing down on it from above). This pressure can be measured and this can be converted into a height above sea level. The instrument for measuring altitude is the altimeter (from "altitude" and "meter"). The common pressure altimeter is a type of barometer with a dial showing distance (feet or metres) instead of atmospheric pressure.
There are several types of aviation altitude.
In simple terms, these types of altitude can be explained as ways of measuring the altitude:
The density of the air also affects how well an aircraft works. Density altitude is affected by barometric pressure, humidity and temperature. On a very hot day, density altitude at an airport (especially one at a high elevation) may be so high that aircraft can not take-off. This most often affects helicopters or an aircraft that is carrying a large amount of cargo.
The Earth's atmosphere is divided into several regions, based on altitude. The regions have different temperatures and winds and what things are in it. The regions are:
Regions on the surface of the Earth or in its atmosphere that are high above mean sea level are said to be high altitude. High altitude is often said to begin at above sea level.
At high altitude, atmospheric pressure is lower than that at sea level. This is because of two effects. These effects are gravity and the heat in the air. Gravity makes the air to be as close as possible to the ground. The amount of heat in the air makes the molecules move quickly and push against each other. This makes the air expand. So most of the air will be in the lower atmosphere, closer to sea level, and all the air pushing against each other is called air pressure. So air pressure is less the higher you go.
As the air expands from heat, it rises to where the air pressure is less. As it rises, it can expand and it begins to cool. Because of this, high altitude air is cold. This causes an alpine climate. This climate affects the ecology at high altitude.
Altitudes above start to affect humans. Humans cannot live in very high altitudes above . Atmospheric pressure decreases at high altitudes. This affects humans because there is less oxygen to breathe. This can cause illnesses such as altitude sickness, high altitude pulmonary edema (fluid in the lungs), and high altitude cerebral edema (fluid in the brain, causing headaches and confusion).
The human body can deal with high altitude by breathing faster, having a higher heart rate, and changing the blood itself to have more red blood cells that can carry oxygen. This can take days or weeks to happen. This works for people who live in the high mountains, and mountain climbers. For climbers, this is called "acclimatization". Pilots and other people who go quickly to high altitudes need to be in a space suit, pressure suit, or inside a pressurized airplane, so the air is still the same as at the ground. Above , the human body cannot make the needed changes and will eventually die. Several of the world's tallest mountains are this high, the climbers usually take oxygen tanks with them, and only stay for a few hours at the highest levels.
People living at higher elevations have a higher rate of suicide. The reason is not yet known.
Focus city
In the airline industry, a focus city is an airport that is important to one airline but is not a hub. An airline has daily flights from the Focus city to many destinations that are also not its hubs. Even though the word ""city"" is part of this term, it means a city's airport, not the city.
An example of an airline's focus city is US Airways (now part of American Airlines) at Washington National Airport in Arlington, Virginia. Focus city airports can have some of the same facilities that hubs have. For example, the airline may repair or clean their aircraft at a focus city because it is cheaper. They might also have places and equipment to handle cargo.
Many low-cost carriers that mostly fly point-to-point use focus cities more than hubs. Southwest Airlines, Spirit Airlines, JetBlue Airways, Allegiant Air and WestJet in the Americas, and Ryanair, EasyJet, Norwegian Air Shuttle and Wizz Air in Europe are examples.
Standing wave
In physics, a standing wave – also called a stationary wave – is a wave that oscillates in one constant position.
The word oscillate simply describes the vibrating movement of particles in a medium when acted upon by a wave, or the regular "up and down" motion shown in the animation. Oppositely to a progressive (moving) wave, stationary waves do not transfer energy in a given direction when they oscillate.