Universe
Universe at a glance
| Age | 13.8 billion years |
| Av. Temp | 2.73 K (−270.4 °C or −454.8 °F) |
| Size | 94 Billion Light Years across |
| Shape | Flat |
What is Universe
The universe is everything that exists, including all the stars, planets, galaxies, and everything else we can see in the sky. Scientists study the universe to try to learn more about how it was created, how it works, and what else might be out there.
What is the study of Universe called?
Astronomy is the study of objects and phenomena beyond Earth. Cosmology is a branch of astronomy that studies the origin and evolution of the universe.
What is the difference between Astronomy and Cosmology
What is the difference between Astronomy and Cosmology
Many of our ancestors have been fascinated by the stars and the moon since ancient times, and they wanted to learn more about them. They also believed that the earth was the center of the universe and that the stars and planets moved around it. This idea, known as the geocentric model, was widely accepted for centuries.
However, in the 16th century, a Polish astronomer named Nicolaus Copernicus challenged this idea. He proposed a new model of the universe, in which the sun was at the center and the planets orbited around it. This idea, known as the heliocentric model, was controversial at the time but eventually gained acceptance.
In the 17th century, a famous astronomer named Galileo Galilei made many important discoveries about the universe. He built a telescope and used it to observe the moon, the sun, and the planets. He discovered that the moon had mountains and craters, that the sun had sunspots, and that Jupiter had four large moons orbiting around it.
In the 17th century, a famous astronomer named Galileo Galilei made many important discoveries about the universe. He built a telescope and used it to observe the moon, the sun, and the planets. He discovered that the moon had mountains and craters, that the sun had sunspots, and that Jupiter had four large moons orbiting around it.
In the 18th and 19th centuries, astronomers made many more discoveries about the universe. They discovered new planets, moons, and comets, and they mapped the positions of many stars. They also began to study the light emitted by stars, which led to the discovery that stars are made up of different elements.
In the early 20th century, a famous scientist named Albert Einstein proposed a new theory of gravity, called the theory of general relativity. This theory explained how gravity works and how it affects the motion of objects in space. It also predicted that the universe was expanding, which was later confirmed by observations made by other astronomers.
In the mid-20th century, astronomers began to use new technologies, such as radio telescopes and satellites, to study the universe. They discovered new types of objects, such as pulsars and quasars, and they mapped the positions of galaxies. They also developed new theories to explain the behavior of the universe, such as the big bang theory, which describes the origins of the universe.
Today, astronomers continue to study the universe using a wide range of technologies and techniques. They use telescopes to observe distant stars and galaxies, satellites to study the earth and other planets in our solar system, and computer simulations to model the behavior of the universe. They are still discovering new things about the universe every day, and their understanding of it is constantly evolving.
In the early 20th century, a famous scientist named Albert Einstein proposed a new theory of gravity, called the theory of general relativity. This theory explained how gravity works and how it affects the motion of objects in space. It also predicted that the universe was expanding, which was later confirmed by observations made by other astronomers.
In the mid-20th century, astronomers began to use new technologies, such as radio telescopes and satellites, to study the universe. They discovered new types of objects, such as pulsars and quasars, and they mapped the positions of galaxies. They also developed new theories to explain the behavior of the universe, such as the big bang theory, which describes the origins of the universe.
Today, astronomers continue to study the universe using a wide range of technologies and techniques. They use telescopes to observe distant stars and galaxies, satellites to study the earth and other planets in our solar system, and computer simulations to model the behavior of the universe. They are still discovering new things about the universe every day, and their understanding of it is constantly evolving.
What is the origin of the universe?
The Big Bang Model is a broadly accepted theory for the origin and evolution of our universe. About 13.8 billion years ago, the portion of the universe we can see today was only a few millimeters across and started expanding extremely rapidly from this hot dense state into the vast and much cooler cosmos we currently inhabit. The Big Bang did not occur at a single point in space as an "explosion." It is better thought of as the simultaneous appearance of space everywhere in the universe. So, our universe was indeed no bigger than a point in the past.
The big bang theory seeks to explain what happened at or soon after the beginning of the universe. Scientists can now model the universe back to 10-43 seconds after the big bang. Because scientists cannot look back in time beyond that early epoch, the actual big bang is hidden from them. There is no way at present to detect the origin of the universe. Further, the big bang theory does not explain what existed before the big bang. It may be that time itself began at the big bang, so that it makes no sense to discuss what happened “before” the big bang.
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According to the big bang theory, the universe expanded rapidly in its first microseconds. A single force existed at the beginning of the universe, and as the universe expanded and cooled, this force separated into those we know today: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force.
The only chemical elements created at the beginning of our universe were hydrogen, helium and lithium, the three lightest atoms in the periodic table. We are carbon-based life forms. We are made of and drink water (H2O). We breathe oxygen. Carbon and oxygen were not created in the Big Bang, but rather much later in stars. All of the carbon and oxygen in all living things are made in the nuclear fusion reactors that we call stars. The early stars are massive and short-lived. They consume their hydrogen, helium and lithium and produce heavier elements. When these stars die with a bang, they spread the elements of life, carbon and oxygen, throughout the universe. The first stars in the universe arose only about 400 million years after the Big Bang.
What is big bang theory
The big bang theory seeks to explain what happened at or soon after the beginning of the universe. Scientists can now model the universe back to 10-43 seconds after the big bang. Because scientists cannot look back in time beyond that early epoch, the actual big bang is hidden from them. There is no way at present to detect the origin of the universe. Further, the big bang theory does not explain what existed before the big bang. It may be that time itself began at the big bang, so that it makes no sense to discuss what happened “before” the big bang.
According to the big bang theory, the universe expanded rapidly in its first microseconds. A single force existed at the beginning of the universe, and as the universe expanded and cooled, this force separated into those we know today: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force.
The only chemical elements created at the beginning of our universe were hydrogen, helium and lithium, the three lightest atoms in the periodic table. We are carbon-based life forms. We are made of and drink water (H2O). We breathe oxygen. Carbon and oxygen were not created in the Big Bang, but rather much later in stars. All of the carbon and oxygen in all living things are made in the nuclear fusion reactors that we call stars. The early stars are massive and short-lived. They consume their hydrogen, helium and lithium and produce heavier elements. When these stars die with a bang, they spread the elements of life, carbon and oxygen, throughout the universe. The first stars in the universe arose only about 400 million years after the Big Bang.
What is big bang theory
