How big is the universe?

There are hundreds of billions of galaxies in the universe ~ 10 12. On average, each galaxy contains about 1000 billion stars ~1kloc-0/1,so the whole universe observed so far contains about 10 165438. 100

000

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000 =1000 trillion Suppose that every star is accompanied by a planet, that is, there are about 1023 planets in the whole universe. Proxima centauri is another star closest to the sun, about 4.28 ly (~ 1.3 1 PC), and it is the Alpha Centauri.

About 4.39 pounds. At present, the farthest galaxy observed is about100 ~1500 million light years ~1023 km, so the observed universe volume since ancient times is about (4/3) * π * (1023) 3 =1070. Now, although we know that stars, like mortals, have the same birth and death, and have a good understanding of the basic properties of various stars, these cannot detract from the beauty of the starry sky. In the suburbs far away from the city's light damage, Du Mu, a poet in the Tang Dynasty, wrote in Autumn Night: "Qiu Guang painted a cold screen with a silver candle, fanned a firefly lightly, and it was as cold as water in the day and night, lying down and watching the morning glory and the weaver star." The artistic conception described in the book remains undiminished. First of all, briefly introduce all kinds of celestial bodies that we know can be seen in the universe. The so-called "seeing" is what the naked eye or various astronomical telescopes see. Planets (PLA): Nine planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto), comets and asteroid stars (stars): Sirius, Vega and Altair (protostar): the main sequence star in the Orion Nebula. Elko coherent measurement radar

UMa) variable star: Cepheid variable star: Polaris, Cepheid variable star with a period of 3.9696 days, and the brightness change is only 0. 1 magnitude. Giant: Aldebaran.

α tau), arcturus.

αBoo), Capella

αAur) Supergiant star: Betelgeuse.

αOri), Betelgeuse (Betelgeuse

βOri nova: nova Cygni 1992 supernova: SN 1987A white dwarf: Sirius B neutron star or pulsar. Neutron star or black hole in the center of the crab nebula: Cygnus X- 1(X-ray source) (probably) cluster (open cluster): Pleiades cluster, Perseus H &；; κ double star cluster (H&; κ Perseus globular cluster): M 13

M 15

NGC 104 Nebula: Orion Nebula, Ring Nebula, Cat's Eye Nebula Interstellar Medium: Silver Disk, Horsehead Nebula Residual: Crab Nebula.

Cygnus Ring Galaxies (Galaxies): Andromeda Nebula M3 1 Quasars (Quasars): 3c273 Galaxy Cluster: Local Group.

Comet cluster

Virgo cluster of clusters Example: Local supercluster: It consists of local cluster and nearby cluster. The Great Wall and Void-Large-scale Structure of the Universe. Astronomers, like us, have always wanted to know how big the universe is. Recently, the American Space Network reported that after hard calculation, astronomers found that the universe is extremely huge, with a length of at least 65.438+056 billion light years. "Such a discovery about the size of the universe is obviously based on the premise that the universe is spherical and finite." Daming Chen, a researcher at the National Astronomical Observatory of China, said in an exclusive interview with reporters, "For a long time, there has been such a debate in the field of cosmology, whether the universe is spherical, saddle-shaped or flat." Zhang Yue, an associate professor at Beijing Normal University, said: "The international mainstream cosmology generally believes that the universe is flat and infinite." So, where does the debate around the universe come from? What makes sense? The most common view is that after the Big Bang, the universe was born. "According to the most influential Big Bang theory in modern cosmology, our universe was produced by a very small point explosion about 65.438+0.37 billion years ago, and the universe is still expanding." Researcher Daming Chen said, "This theory has been confirmed by a large number of astronomical observations." This theory holds that in the early days of the birth of the universe, the temperature was very high. With the expansion of the universe, the temperature began to drop, producing neutrons, protons and electrons. Since then, these elementary particles have formed various elements. These particles attract and fuse with each other, forming larger and larger clumps, and gradually evolving into galaxies, stars and planets. Life phenomena have appeared on individual celestial bodies, and finally human beings who can understand the universe have been born. Is the universe spherical and finite? "The idea that the universe is spherical has existed for a long time, although it is not the mainstream of the international cosmology community." Daming Chen said, "Every time it is mentioned, it will attract people's attention, because this view is very strange." One of the most obvious examples is the universe model established by American mathematician Jeffrey Wilkes not long ago: a mirror maze of limited size, shaped like a football. The model of "shaped like a football" shocked the scientific community, because this theory claimed that the universe produces an "illusion" without boundaries because this limited space reflects itself endlessly through the "circle" effect. Wilkes believes that people think that the universe is infinite because the universe is like a mirror maze, and light shuttles back and forth, giving people the illusion that the universe is infinitely extended. This amazing inference was later included in New Scientist magazine and widely circulated among the people as a kind of "strange talk". Just recently, similar amazing news came from the American space network. A writer learned after visiting a famous astrophysicist in this country that the length of the universe is 65.438+056 billion light years. In this new study, researchers examined the primary radiation left in the vast universe after the Big Bang. They come to the conclusion that there may be some magical cosmic "mirror room" in the universe, so that an object can be seen in two places. Because of this conclusion, they became supporters of "spherical cosmology". The length is156 billion light years? Why is the size of the universe a number you have never heard of? Their explanation is this: the age of the universe is about 65.438+037 billion years. It takes1300 million years for light to reach the earth from the earliest known galaxy. So we can assume that the radius of the universe is 65.438+037 billion light years, so the length of the whole universe is twice the radius of the universe, which is 27.4 billion light years. But it has been expanding since it came into being. Theorists believe that the universe originated from a point with infinite density. Professor Neil Cornish, an astrophysicist at Montana State University, explained: "The distance of light propagation in the early universe increased with the expansion of the universe, just like compound interest in a bank." He suggested that it is conceivable that the universe was only 654.38+0 million years after its birth. Light travels through a year, with a distance of 1 light year. He said: "At that time, the size of the universe was about 1 000 times smaller than it is now, so the extension of 1 light-year is now 1 000 light-year." All the distances add up to 78 billion light years. He said that light has not gone that far, "but the starting point of photons that reached our earth in 65.438+0.37 billion years is now 78 billion light years away. This is the radius of the universe, so the diameter is156 billion light years. This is only based on the fact that it takes 95% of the time for light to return, so the actual length of the universe may be longer. Scientists studied the cosmic microwave background radiation (CMB) formed 380,000 years after the Big Bang, when the universe expanded and cooled enough to form atomic matter. The difference of radiation temperature in different directions in the sky can be used to indicate the age of the universe and constrain many important cosmological parameters. The cosmic microwave background radiation is an image of the universe in its infancy, before stars formed. On May 2 1 2004, the American Journal of Physical Review published this new research work, focusing on the phenomenon that the universe is like a pair of mirror rooms by using cosmic microwave background radiation data. Accordingly, multiple images of the same object in the universe can be presented in different places in time and space. The mirror room effect may mean that the universe is finite, but it produces the feeling that the universe is infinite. He told reporters

"There is no indication that the universe is finite, but this does not prove that it is infinite." 2006-12-0212:14: 24 supplement: 199 1, American cosmic background detection satellite found that there was slight temperature fluctuation in cosmic background radiation, just like a faint "fire" flashing in "embers". The "Extragalactic Millimeter Wave Radiation and Geophysical Balloon Observation Project" is based on the discovery of this satellite. In addition, Hubble telescope and gamma ray detector, which went into space in April 19965438 and April/kloc-0 respectively, also observed the structure and evolution of the universe and achieved a lot of results. These results agree that the universe will continue to expand.

The universe can be finite or infinite. A simple example is that our earth is finite but has no farthest boundary, because it is round (it is formed in three-dimensional space), but the universe we see at present is incomplete, so we need to understand how big the universe is in more dimensions. In the universe

Scientists estimate that there are hundreds of billions of galaxies

Each galaxy has hundreds of billions of stars (such as our sun)

Most stars have planets ... more or less ... only a few of you know how much the universe is beyond your imagination.

Reference: Astronomy as I know it.

The universe will continue to expand, and there will always be more than/kloc-0 10000000000 planets.

The universe is really hard to talk about, but the family is still expanding. Even if it is a little bigger than you know, the next second may be different. Although I know there are many solar systems in the universe, we haven't been able to go to the only 12 planet found so far. Maybe in the future, I will find something better, only what I know is wild and wrong.

Reference: Self-knowledge

Nobody knows how big it is!

In fact, today's science

There is not enough technology to verify the size of the universe. I can't count how many planets there are. So there is someone who can tell you this question.

This truth can't answer you, because the week accommodates hundreds of millions of planets, and the clock will continue to expand.