relativity is a basic theory about space-time and gravity, mainly founded by Albert Einstein. It is divided into special relativity and general relativity according to different research objects. The basic assumption of relativity is the principle of relativity, that is, the laws of physics are independent of the choice of reference frame.
10. Is there life on Mars
Martian life Martian life for thousands of years, scientists have been studying whether there is life on Mars. Now, space experts have pointed out that there is huge frozen water under Mars, and water is the source of human survival. With the continuous development of science, Mars may become the second earth suitable for human survival.
9. Habitable planet
Habitable planet (habitable planet, life bearing planet) is a special term in astronomy. It refers to the planet suitable for human survival. Scientists have been trying to find such a planet. If the earth dries up in the future, we can rely on the technology at this time to live on these planets.
8. Eagle Nebula
Introduction the Eagle Nebula (also known as NGC 6611) ranks 16th in the Messier catalog, so it is called M16 for short. It is a Nebula located in the constellation serpentine, a star birth region of the Milky way, and an ionized hydrogen region. It is named because it looks like an eagle flying with its wings. Observation M16 is located on the Sagittarius Arm (or Sagittarius bottom arm) of the galaxy. It is a celestial body easy to be observed by binoculars or small telescopes.
7. How do galaxies come into being
Introduction galaxy is derived from the Greek & gamma& alpha;& lambda;& alpha;& xi;&# 943;& alpha;& sigmaf; ( galaxias)。 In a broad sense, galaxies refer to the operating system composed of countless star systems (including stars themselves) and dust (such as nebulae). Referring to the Milky way, it is a large galaxy that contains stars, interstellar matter of gas, cosmic dust and dark matter, and is bound by gravity.
6. Unknown substance
Introduction composition analysis of unknown substances is usually divided into two categories. One is principal component analysis. Generally speaking, it is easy to analyze the principal component. The second type is total component analysis, which makes qualitative and quantitative analysis on the component content of the object.
The chemical structure of each component in the unknown is obviously different, which shows that they have different chemical and physical properties. The idea system of unknown component analysis method is to use their differences in chemical and physical properties, select different chemical and physical separation methods to separate them one by one, and then test and identify them with chemical and large-scale precision analysis instruments. 5. Advanced civilization of the universe
In the vast universe, the civilization established by human beings on earth is insignificant. Because the earth's civilization is so short, it is only tens of thousands of years since mankind began to create civilization, only a few hundred years after the development of science and technology, and only a few decades after the exploration of aerospace technology. Compared with the 4.6 billion years old of the earth and the 10 billion to 15 billion years old of the Milky way, this is nothing but a drop in the ocean.
4. UFO
Introduction UFO (unidentified flying object, abbreviated as UFO) refers to objects with unknown origin, unknown nature, floating and flying in the sky. It is called UFO in Taiwan[ 1]
Classification UFO phenomena can be roughly divided into four categories: misidentification of known phenomena, unknown natural phenomena and unknown natural organisms. The fourth category refers to aircraft with obvious intelligent flight ability rather than those made by earth people, that is, flying saucer of alien civilization. It can be seen that UFOs cannot be equated with alien flying objects.
Characteristic UFO: refers to spacecraft from other planets, while UFO has a much wider range. Since the 1940s, saucer flying objects have been found over the United States. At that time, newspapers called them 'flying saucers', which is the beginning of contemporary interest in UFOs. Later, people focus on UFO reports all over the world, but so far, no evidence that can be generally accepted by the scientific community to explain that they come from extraterrestrial civilization has been found. The word UFO comes from the 'blue book program' of the US air force. The first person in charge of the program was Edward & middot; Captain Rupert, he officially invented the word "UFO" (literally translated as UFO), replacing the inaccurate and suggestive word "UFO" used at that time.
3. Einstein's theory of relativity
Introduction relativity is the basic theory of space-time and gravity, mainly by Albert & middot; Einstein was founded and divided into special relativity and general relativity according to different research objects. The basic assumption of relativity is the principle of relativity, that is, the laws of physics are independent of the choice of reference frame. Content the difference between special relativity and general relativity is that the former discusses the physical laws between reference frames of uniform linear motion (inertial reference frame), while the latter is extended to reference frames with acceleration (non inertial frame), and is widely used in gravitational field under the assumption of equivalence principle. Relativity has greatly changed mankind's "common sense" concept of the universe and nature, and put forward new concepts such as "simultaneous relativity", "four-dimensional space-time" and "curved space-time". It developed Newtonian mechanics and promoted the development of physics to a new height.
The principle of special relativity is two basic assumptions of relativity. Under the observation of current experiments, the motion of objects is in good agreement with relativity, so it is generally believed that relativity is a correct theory.
2. Dark energy
Characteristic dark energy is a kind of energy that drives the motion of the universe. Neither it nor dark matter can absorb, reflect or radiate light, so human beings can not directly use the existing technology for observation.
1. Parallel universe
Parallel universes refer to the universes contained in the multiverse. The multiverse is a theoretical set of infinite possible universes, including all existing and possible things: all space, time, matter, energy and the physical laws and physical constants that describe them.