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Space is the limitless three-dimensional extension in which objects and events have relative position and direction.Physical space is often thought of in three linear dimensions, though modern physicists usually view it as part of a boundless four-dimensional continuum known as space-time. The concept of space is considered fundamental to understanding the physical universe. However, there is still disagreement between philosophers as to whether it is an entity, a relationship between entities, or part of a conceptual framework.

In Scientific words

From the perspective of an Earth dweller, space is a zone that is about 100 kilometers above the planet, and where there is no appreciable air to breathe or scatter light. In this area, blue gives way to black because oxygen molecules are not available in sufficient quantities to make the sky blue. In addition, the space is a vacuum, which means that sound can not be transported because the molecules are not close enough to transmit sound between them. This does not mean that the room is empty. Gas, dust and other matter float in “emptier” areas of the universe, while crowded regions can house planets, stars and galaxies. No one knows exactly how big the room is. The difficulty arises from what we can see in our detectors. We measure long distances in space in “light years”, which is the distance that light travels in one year (about 5.8 trillion miles or 9.3 trillion kilometers). From the light visible in our telescopes, we have mapped galaxies that go back almost to the Big Bang, which is believed to have started our universe 13.7 billion years ago. This means that we can “see” into space at a distance of nearly 13.7 billion light-years. However, astronomers are not sure if our universe is the only universe that exists. This means that the room can be much larger than it appears to us.

Most of the space is relatively empty, which means that there are only a few dust and gas particles in it. This means that when humans send a satellite to a distant planet, the object does not “drag” in the same way as an airplane does when it sails through space. The vacuum environment in space and on the moon, for example, is one reason why the lunar module of the Apollo program looks so weird – like a spider, a crew said. Since the spacecraft was designed to operate in an atmosphere-free zone, neither smooth edges nor aerodynamic shape were required. While space looks empty to the human eye, research has shown that there are forms of radiation that radiate through the cosmos. In our own solar system, the solar wind, which is composed of plasma and other particles of the Sun, pervades the planets and occasionally causes auroras near the poles of the Earth. Cosmic rays also fly through the neighborhood, emanating from supernovas outside the solar system. In fact, the universe permeates the cosmic microwave background, which can be understood as the remnant of the massive explosion that has formed our cosmos (commonly referred to as the Big Bang). The best seen in microwaves, the CMB shows the earliest rays our instruments can detect. A great feature of space that is poorly understood or understood is the presumed presence of dark matter and dark energy, which are essentially forms of matter and energy that can only be grasped by their impact on other objects. As the universe expands and accelerates in this expansion, this is considered to be a substantial proof of dark matter. Another problem is the gravitational lens, which occurs when light is “bent” around a star from a distant background object.

Black holes

Smaller black holes can be formed by the gravitational collapse of a gigantic star forming a singularity from which nothing can escape – not even light, hence the name of the object. No one is quite sure what is in a black hole or what would happen to a person or object that fell into that hole – but the research is not yet complete. An example is gravitational waves or ripples in space-time caused by interactions between black holes.

Stars, planets, asteroids and comets

Stars (like our sun) are huge balls of gas that produce their own radiation. You can range from red supergiants, to cooling white dwarves that are the remnants of supernova, to star explosions that emanate when a large fuel burns out.

These explosions spread throughout the universe and are the reason why elements like iron exist. Star explosions can also lead to incredibly dense objects called neutron stars. When these neutron stars emit radiation pulses, they are called pulsar stars. Planets are objects whose definition was scrutinized in 2006 when astronomers discussed whether or not Pluto can be considered a planet. At that time, the International Astronomical Union decided that a planet is a celestial body orbiting the Sun, massive enough to have an almost circular shape, and its orbit free of debrishas made. Under this designation Pluto and similar small objects are regarded as “dwarf planets”, although not everyone agrees with the designation. After the New Horizons spacecraft flew from Pluto in 2015, senior investigator Alan Stern and others re-opened the debate, saying that Pluto’s terrain diversity is more like a planet. The definition of extrasolar planets or planets outside the solar system is not yet concretized by the IAU, but astronomers basically understand objects that behave like planets in our neighborhood. The first such planet was found in 1992 (in the constellation Pegasus) and since then thousands of alien planets have been confirmed – with many other suspicions. In solar systems where planets are in formation, these objects are often referred to as “protoplanets” because they are not quite as mature as the planets we have in our own solar system. Asteroids are rocks that are not big enough to be dwarf planets. We even found asteroids with rings, like 10199 Charilko. Their small size often suggests that they are remnants from the time of the formation of the solar system.

Most asteroids are concentrated in a belt between the planets of Mars and Jupiter, but there are also many asteroids that follow behind or in front of planets, or even cross on the way of a planet. NASA and several other companies have asteroid search programs that can search for potentially dangerous objects in the sky and closely monitor their orbits. Comets (sometimes called dirty snowballs) are objects in our solar system that are believed to come from a vast collection of icy bodies called the Oort Cloud. As a comet approaches the sun, the heat of our star melts the ice and streams away from the comet. The ancients have often associated comets with destruction or some kind of immense change on Earth, but the discovery of Halley’s comet and the associated “periodic” or returning comets showed that these were ordinary solar system phenomena.

Galaxies and quasars

Among the largest cosmic structures we can see are galaxies, which are essentially large accumulations of stars. Our own galaxy is called the Milky Way and is considered a “Barred Spiral” shape.

There are several types of galaxies that can range from helical to elliptical to irregular and can change as they approach other objects or as stars age in them. In galaxies, supermassive black holes are often embedded in the center of their galaxies, visible only through the radiation emitted by each black hole and its gravitational interactions with other objects. If the black hole is particularly active and a lot of material falls into it, it generates immense amounts of radiation. This type of galactic object is called quasar.

Large groups of galaxies can form in clusters as large as hundreds or thousands of galaxies connected by gravity. Scientists consider these as the largest structures in the universe.