ejaasaari/simplewiki-2025-04-01 huggingface dataset:
Metaphor is a term for a figure of speech. It does not use a word in its basic literal sense. Instead, it uses a word in a kind of comparison. We run, and we also say rivers run. We may run into trouble, especially if we run up a bill at the bar. So a metaphor uses words to make a picture in our mind. It takes a word from its original context, and uses it in another. "I beat him with a stick" = literal meaning of 'beat'. "I beat him in an argument" = metaphorical meaning of 'beat'. Metaphors are an essential part of language: it is not possible to speak or write without them. A simple example is the word "run". This has a basic meaning of "moving quickly" or "go with quick steps on alternate feet, never having both feet on the ground at the same time". The "Concise Oxford Dictionary" then gives 34 other uses as a verb; 21 uses as a noun; about 50 uses in short phrases. All of these are metaphors, although we do not usually notice this. We use metaphors to make "indirect" comparisons, but without using 'like' or 'as' – because that would be a simile. A simile is a "direct" comparison: "Jane is like a child". A metaphor very often uses the verb 'to be': "love "is" war", for example, not "love "is like" war" (that is a simile). Poetry includes much metaphor, usually more than prose. Spam is an example that any email user knows about – this word was originally a metaphor, from 'Spam', a type of canned meat. Servers putting unwanted email into somebody's inbox was similar to waiters putting unwanted Spam into food. This was originally suggested by a Monty Python scene. When we use a metaphor very often and we forget the old meaning, or forget that the two meanings are connected, this is a 'dead metaphor'. Originally "metaphor" was a Greek word for 'transfer'. It came from "meta" ('beyond') and "pherein" ('carry').
Metabolism is the chemical reactions which keep us alive. It happens in the cells of living organisms. The chemical reactions are catalyzed by enzymes. Metabolism allows organisms to grow, reproduce, maintain their structures, and respond to their environments. The word ‘metabolism’ can also refer to digestion and the transport of substances into and between different cells. Metabolism is usually divided into two categories: The chemical reactions of metabolism are organized into metabolic pathways, or cycles, like the Krebs cycle. One chemical is transformed through a series of steps into another chemical by a series of enzymes. The metabolic system of an organism decides which substances it finds nutritious and which poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The speed of metabolism, called the metabolic rate, influences how much food an organism will need, and how it is able to get that food.  A striking feature of metabolism is the similarity of the basic metabolic pathways and components between even vastly different species. For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all known organisms, being found in species as diverse as the unicellular bacterium "Escherichia coli" and huge multicellular organisms like elephants. These striking similarities in metabolic pathways are likely due to their early appearance in the evolution of life, and kept because of their efficiency.
A microscope is a scientific instrument. It makes small objects look larger. This lets people see the small things. People who use microscopes frequently in their jobs include doctors and scientists. Students in science classes such as biology also use microscopes to study small things. The earliest microscopes had only one lens and are called "simple microscopes". "Compound microscopes" have at least two lenses. In a compound microscope, the lens closer to the eye is called the "eyepiece". The lens at the other end is called the "objective". The lenses multiply up, so a 10x eyepiece and a 40x objective together give 400x magnification. Microscopes make things seem larger than they are, to about 1000 times larger. This is much stronger than a magnifying glass which works as a simple microscope. Types of microscopes. There are many types of microscopes. The most common kind of microscope is the compound light microscope. In a compound light microscope, the object is illuminated: light is thrown on it. The user looks at the image formed by the object. Light passes through two lenses and makes the image bigger. The second most common kind are a few kinds of electron microscopes. Transmission electron microscopes (TEMs) fire cathode rays into the object being looked at. This carries information about how the object looks into a magnetic "lens". The image is then magnified onto a television screen. Scanning electron microscopes also fire electrons at the object, but in a single beam. These lose their power when they strike the object, and the loss of power results in something else being generated—usually an X-ray. This is sensed and magnified onto a screen. Scanning tunneling microscopes were invented in 1984. A fluorescence microscope is a special kind of light microscope. In 2014, the Nobel Prize in Chemistry was awarded to Eric Betzig, William Moerner, and Stefan Hell for "the development of super-resolved fluorescence microscopy". The citation says it brings "optical microscopy into the nanodimension".
The mass of an object is a measure of the amount of matter it has. A mountain has a greater mass than a rock, while mass is different weight, which is the vector (directional) product of mass and gravitational acceleration, e.g. 9.81 ms-2. Weight is sometimes called the "force of gravity". The mass of an object is measurable when a force is exerted on the object. If the mass is greater, the object will have less acceleration (changes in velocity), which is sometimes called "inertial mass" as it measures the inertia. A gigantic mass, like our planet Earth, attracts such a smaller mass as human being to keep the human being from floating away from the Earth's surface. "Mass attraction" is another word for gravity, a force existing between all matters. When measuring the "force of gravity" exerted on an object, its "gravitational mass" can be found. Tests of inertial and gravitational mass show that they are the same or almost the same. Units of mass. The unit of mass in the International System of Units is the kilogram, which is represented by the symbol 'kg'. Fractions and multiples of this basic unit include the gram (one thousandth of a kg, symbol 'g') and the tonne (one thousand kg), amongst many others. In some fields or applications, it is convenient to use different units to simplify the discussions or writings. For instance, Traditional units are still in encountered in some countries: imperial units such as the ounce or the pound were in widespread use within the British Empire. Some of them are still popular in the United States, which also uses units like the short ton (2,000 pounds, 907 kg) and the long ton (2,240 pounds, 1010 kg), not to be confused with the metric ton (1,000 kg). Conservation of mass and relativity. Mass is an intrinsic property of the object: it does not depend on its volume, or position in space, for instance. For a long time (at least since the works of Antoine Lavoisier in the second half of the eighteen century), it has been known that the sum of the masses
Mercury is the smallest planet in the Solar System. It is the closest planet to the sun. It makes one trip around the Sun once every 87.969 days.  Mercury is bright when we can see it from Earth. It has an apparent magnitude ranging from −2.0 to 5.5. It cannot be seen easily because it is usually too close to the Sun. Because of this, Mercury can only be seen in the morning or evening twilight or when there is a solar eclipse. Less is known about Mercury than about other planets of our Solar System. Even with telescopes only a small, bright crescent can be seen. It is also hard to put a satellite in orbit around it. Two spacecraft have visited Mercury. The first one was Mariner 10. It only made a map of about 45% of the Mercury's surface from 1974 to 1975. The second is the MESSENGER spacecraft, which finished mapping Mercury in March 2013. Mercury looks like Earth's Moon. It has many craters and smooth plains. It has no moons and little atmosphere as we know it. However, Mercury does have an extremely thin atmosphere, known as an exosphere. Mercury has a large iron core. Because of this Mercury has a magnetic field about 1% as strong as that of the Earth. It is a very dense planet because its core is large.  Temperature at the surface can be anywhere from about 90 to (−183 °C to 427 °C, −297 °F to 801 °F), with the subsolar point being the hottest and the bottoms of craters near the poles being the coldest. Known sightings of Mercury date back to at least the first millennium BC. Before the 4th century BC, Greek astronomers thought that Mercury was two different objects: The one that they were only able at sunrise, they called Apollo; the other one that they were only able to see at sunset, they called Hermes. The English name for the planet is from the Romans, who named it after the Roman god Mercury. The symbol for Mercury is based on Hermes' staff. Even though Mercury is the closest planet to the Sun, it
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, nicknamed The Red Planet. Mars is a terrestrial planet with caps of water and carbon dioxide. It has the largest volcano in the Solar System, and some very large impact craters. Mars is named after the mythological Roman god of war because it appears of red color. Anything that has to do with Mars is called "Martian". Space probes, such as the Viking program landers, are the main tools for the exploration of Mars. Appearance. Mars is a terrestrial planet and made of rocks. The ground there is red because of iron oxide (rust) in the rocks and dust. The planet's atmosphere is very thin. It is mostly carbon dioxide with some argon and nitrogen and tiny amounts of other gases including oxygen. The temperatures on Mars are colder than on Earth, because it is farther away from the Sun and has less air to keep heat in. There is water ice and frozen carbon dioxide at the north and south poles. Mars does not have any liquid water on the surface now, but signs of run-off on the surface were probably caused by water. The average thickness of the planet's crust is about 50 km (31 mi), with a maximum thickness of 125 km (78 mi). Moons. Mars has two small moons, called Phobos and Deimos. The origin of Mars' moons is unknown and controversial. One theory is that the moons are captured asteroids. However, the moons' near circular orbits and low inclination relative to the Martian equator are not in agreement with the capture hypothesis. Estimates of the mass ejected by a large Borealis-size impact vary. Simulations suggest that a body about 0.02 of Mars mass (~0.002 Earth mass) in size can produce a sizable debris disk in Martian orbit. Much of the material would stay close to Mars. There are several other large impact basins on Mars that could also have ejected enough debris to form the moons. Physical geography. Lack of magnetic field. Mars does not have a global magnetic field. Despite this, observations show that parts of the planet's crust have been magnetized. This suggests that
Mac OS is an operating system for Macintosh computers. Mac OS was first made by Apple Inc. in 1984. In those days Mac OS was called Macintosh System Software – which was shortened to System or SSW (System Software). The term "Mac OS" first appeared in the splash screen for System 7.5.1, but was not adopted as the new name until the release of Mac OS 7.6.
The Apple Macintosh or just Mac is a line of personal computers made by the American company Apple Inc. The Macintosh was one of the first computers in which the people could use a mouse for pointing on a screen which had icons. This new way of working with a computer (interface) was known as graphical user interface. It was this feature of the Macintosh that made it so popular. History. Processor history. The Apple–Intel transition was when Apple changed the CPU of Macintosh computers from PowerPC processors to Intel x86 processors. It was announced at the 2005 World Wide Developers Conference. Steve Jobs announced it. Macintoshes were different than other personal computers for many years based on their central processing unit (CPU). At the start, Macs used Motorola 68000 chips instead of Intel chips. Later, Macs used PowerPC chips. In 2006, Macs started to use Intel chips. In 2020, Macs started to use Apple Silicon chips. Today, Macs are sold with Apple M1 chips. Macintoshes. Software. The Mac does not have the Windows operating system installed on it. It has its own range of operating systems, known as macOS. The newest operating system is known as “Sonoma". Macs can run both Windows and macOS at the same time with help of a program called “Boot Camp”, which comes on every Mac. In general, Macintosh computers cost more than other computers of the same speed.
A metre (US spelling, "meter") is the basic unit of length in the SI measurement system. The symbol for the metre is m. The first meaning (in the French Revolution) was one ten-millionth of the distance between the Earth's equator and the North Pole along the Paris meridian. The metre is now defined as the distance light travels in a vacuum in 1/299,792,458 of a second. In the imperial system of measurement, one yard is 0.9144 metres (after international agreement in 1959), so a metre is very near to 39.37 inches: about 3.281 feet, or 1.0936 yards.
A magnifying glass is a lens through which can be used to make things appear bigger, so you can see them better. It is used in many applications and manual operations, e.g., for examining postage stamps in philately. The magnifying glass consists of a piece of convex-shaped glass or plastic. It has to be held at the right distance between the eye and the object for the object to be in focus. The magnifying glass usually comes with a handle. A telescope is a more advanced kind of magnifying glass and consists of at least two glass lenses.  A pair of binoculars is like a telescope for each eye. "Spectacles" or eyeglasses also use lenses to correct a person's vision.
A molecule is the smallest amount of a chemical substance that can exist. If a molecule were split into smaller pieces, it would be a different substance. Molecules are made up of atoms that are stuck together in a particular shape or form. Not all combinations of atoms are equally possible; atoms make certain shapes in preference to others. Also, they have different valency. For example, oxygen atoms always have two bonds with other atoms, carbon atoms always have four bonds with other atoms, and nitrogen atoms always have three bonds with other atoms. In the kinetic theory of gases, the term "molecule" is often used for any gaseous particle regardless of its composition. According to this definition, noble gas atoms are considered molecules as they are in fact monoatomic molecules. In gases like air, the molecules are just flying around. In liquids like water, the molecules are stuck together but they can still move. In solids like sugar, the molecules can only vibrate. In the fourth state of matter known as plasma, the atoms are ionized and cannot form molecules. With a molecular formula, you can write down the numbers of all atoms in a molecule. For example, the molecular formula of glucose is C6H12O6. That means that one molecule of glucose is made up of six carbon atoms, twelve hydrogen atoms and six oxygen atoms. Bonding. For a molecule to exist, atoms have to stick together. This happens when two atoms share electrons. Instead of circling just one atom, the electron now circles around two. This is called a covalent bond. Sometimes, more than one electron is shared. The more electrons are shared, the stronger the bond gets and the stronger the atoms stick together. Bonds can also be broken apart. Since most bonds require energy to form, they also give off energy when they are broken. But before most bonds break, the molecule has to be heated. Then the atoms start to move, and when they move too much, the bond breaks. Molecules that require less energy to break than they give off when broken are called fuels. For example, a candle will just sit there and nothing happens. But when you use a match to light it, it will burn for a long time. The match brings the energy to break the first bonds, which release enough energy to break the bonds below them, until the candle has burned down. There are also ionic bonds.
Moral reasoning is a topic studied in psychology and in moral philosophy. It studies how people think about moral issues, problems, and questions. Psychologists who have studied it include Lawrence Kohlberg and Elliot Turiel. Kohlberg said that moral understanding develops in three main stages as a person gets older, but Turiel said that there are three domains of moral understanding that develop at the same time as a person gets older. Moral philosophy, or ethics, is a major branch of philosophy. It is the study of value or quality. It covers the analysis and use of concepts such as right, wrong, good, evil, and responsibility.
A mosque is a place where Muslims worship. The word "mosque" comes from the Arabic word "masjid". A larger, 'collective', mosque is called a "masjid jāmi". Larger mosques offer more services to their community. For many Muslim people, a mosque is more than a place of worship. Muslims worship, study and discuss Islam, and do many other things in a mosque and its compounds. In the United Kingdom, many mosques are used as community centres. They are also used to teach about Islam. Religious festivals and gatherings are held in mosques. Weddings are one example. Mosques have rules to control what people do inside. One of these is that it is disrespectful to disturb another person who is worshipping. Many mosques are known for their Islamic architecture. The earliest mosques, opened in 7th century were open-air spaces. They are the "Quba Mosque" and "Masjid al-Nabawi". Later Mosques were buildings that were specially designed. Nowadays, mosques are in every continent, except Antarctica. Architecture. Many mosques are famous works of architecture. They are often built in a style that has stayed the same for many centuries. Many mosques have prayer halls, domes, and minarets. They may also have a courtyard. Mosques are often built with patterned walls. Mosques were first built on the Arabian Peninsula. The Muslims who built them used old architectural styles. They also combined these styles in new ways. A major influence was the palaces built during the Parthian and Sassanid dynasties of Persia. The "Sarvestan palace" from the Sassanid era is a good example of this. It has an arched entrance and a central dome. These features already existed in Persia before Islam. After the Arab invasion of Persia, the new style, with its Sassanid influence, was used for the new Islamic world. Many forms of mosques have developed in different regions of the Islamic world. Important mosque types include the early Abbasid mosques, T-type mosques, and the central-dome mosques of Anatolia. In the 20th century, many countries that grew rich from oil paid for the building
Mammals are in the class Mammalia. They are a group of vertebrate animals. They have fur or hair and very precise temperature regulation. With the exception of the monotremes, all mammals bear live young. Unlike other vertebrates, they are the only animals that produce milk for their young through their mammary glands. Parental care of the young is universal among mammals, sometimes for long periods. Mammals became the dominant land animals after non-bird dinosaurs were eliminated. Recent work helped to explain their success: epigenetics seems to have started in early mammals. Main characteristics. Reproductive cycle. Most marsupial and eutherian mammals have a reproductive cycle known as the oestrous cycle (U.S: estrous cycle). Females are sexually active in the oestrous stage, when they are 'on heat' for a few days each month. If an ovum is not fertilized, the endometrium (uterus lining) is resorbed. Oestrus cycles may occur once or twice a year, or many times a year. Each type of mammals has its own frequency. Humans and primates, are quite different. They have a menstrual cycle. In this case, females are sexually receptive at any time, but only fertile when an ovum is released from an ovary. In this case, the endometrium (if not needed for an fertilised egg) is discarded. In this system, eggs are released from the ovaries mostly in the middle of the cycle, away from the menstrual period. This ovulation is 'concealed', meaning, it is not obvious when it occurs. This process, so it is thought, tends to keep the male and female together, which is unusual in mammals with the oestrous cycle. Keeping males and females together is related to the long learning period of primates. Skeleton. One diagnostic feature of mammals is the lower jaw. Unlike earlier forms, it is a single bone, the dentary. This is one feature which can be seen in fossils, or at least those which are complete enough to have the lower jaw. Another diagnostic feature is the ear ossicles. Mammals have three little
A number is a mathematical object used to count, measure, and label: Numbers are also used for other things like counting. Numbers are used when things are measured. Numbers are used to study how the world works. Mathematics is a way to use numbers to learn about the world and make things. The study of the rules of the natural world is called science. The work that uses numbers to make things is called engineering.  Numbering methods. Numbers for people. There are different ways of giving symbols to numbers. These methods are called number systems. The most common number system that people use is the "base 10" number system. The "base 10" number system is also called the decimal number system. The base 10 number system is common because people have 10 fingers and 10 toes. There are 10 different symbols (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9) used in the base 10 number system. These 10 symbols are called digits. A symbol for a number is made up of these 10 digits. The position of the digits shows how big the number is. For example, the number 23 in the decimal number system really means (2 times 10) plus 3. Similarly, 101 means 1 times a hundred (=100) plus 0 times 10 (=0) plus 1 times 1 (=1). Numbers for machines. Another number system is more common for machines. The machine number system is called the "binary" number system. The binary number system is also called the base two number system. There are two different symbols (0 and 1) used in the base two number system. These two symbols are called bits. A symbol for a binary number is made up of these two bit symbols. The position of the bit symbols shows how big the number is. For example, the number 10 in the binary number system really means 1 times 2 plus 0, and 101 means 1 times four (=4) plus 0 times two (=0) plus 1 times 1 (=1). The binary number 10 is