It is said that the universe is very large, and the distance between the planets is tens of thousand

- Upstairs there are talented ......You remember wrong, the mass of gravitational measurement is about the same, and the distance is difficult to say......This is because there is no guarantee that there will be other forces at the time of measurement......The upstairs is good, it's the ...... measured with optical red shift

Didn't you study optics in high school? Do you know about redshifts? One I know is astronomy, where redshift is used to measure distances.

First of all, you have to know"Light years"This unit is a unit of distance, and the light emitted by a star at a distance of x light years, after x years of light propagation, is detected as the state of the planet when it emits this light, that is, the state of x years ago, and does not represent its current state.

As long as the ability to emit light is strong, distance is not an issue. Moreover, our astrophotography can also subjectively increase the brightness of celestial bodies through a long period of time**, and some celestial objects that are too far away and too faint to be seen can be seen.

It is because the light (or other electromagnetic waves and rays) emitted by stars hundreds of light-years or even hundreds of millions of light-years away has traveled through the universe for hundreds of millions of years, reached the earth, and was received by scientists. What we see is what these stars looked like hundreds of millions of years ago, and it is impossible to know what they look like now.

It shouldn't be probing, it's analytical! So far, as far as I know, after the Moon and Mars

Because what we're seeing is what happened hundreds of millions of years ago, and the light has run to Earth, just like the sun we see was the sun eight minutes ago.

For more recent objects (within 500 light years), triangulation is used.

500 100,000 light-year objects use photometric methods to determine distances.

Astronomers 100,000 light-years away have found Cepheids as a standard, up to a range of 500 million light-years.

The longer distance is calculated using the observed redshift, based on Hubble's theorem.

I remember it seems"Light"Walked in the universe for a year to get to the place!It's called a light year.

The observable universe is 93 billion light-years. The universe is filled with all kinds of celestial bodies. The number of objects within 40 million light-years of the Earth would be very large.

Recently, NASA photographed a galaxy 44 million light-years away from Earth, NGC5866, which is about 60,000 light-years in diameter.

1. Parallax method, the parallax method is a method of calculating the distance between the planet and the earth invented by the German astronomer Bessel. His principle is that when the human eye observes a planet about 100 light-years away from the Earth, then for the planet farther away from the planet, the planet will move a distance, which is due to a phenomenon produced by people observing it at different angles on the other side of the Earth, and we call this phenomenon of the observed motion of the planet parallax.

As shown in the diagram, the distance between the earth and the sun is an astronomical unit, and when calculating the distance between a celestial body and the sun, the distance between the two is very far, much farther than the distance between the earth and the sun, so it can be approximated that the distance d is approximately equal to the distance from the earth to this celestial body. In the diagram, when the angle p is an arc second of a triangle, it is a unit of length in astronomy. Measuring distances using the parallax method requires a combination of telescopes and can only be accurate when measuring the distance between a planet and Earth within 50 light-years.

2. By comparing and analyzing the absolute magnitude of the star and the spectral intensity of the light of the traveling star, a star at a distance of 1000 light-years from the Earth can be inferred from its visible brightness and distance formula, so when measuring a star with the same absolute magnitude as the star, but looking fainter, then it should be farther away from the Earth, so the distance between celestial bodies can be calculated by measuring its brightness.

Absolute magnitude has actually been used in ancient times, and used to describe the brightness of stars, the smaller the magnitude value, the brighter the star, the brighter the star with a value of 1 is 100 times brighter than a star with a value of 6, and the faintest magnitude value that we can observe with the naked eye is. According to modern optical knowledge, when a planet has the same intrinsic brightness, its visible brightness is inversely proportional to the square of the distance.

After recording a large amount of data, scientists have made a comparison table of the brightness and distance of the star, and now as long as the brightness of the star is observed by a professional measuring telescope, and then according to the intrinsic brightness of the star, the corresponding distance can be found in the table.

It is calculated through some formulas, such as the parallax method, and I have done a similar problem in high school, that is, at the bottom of A to see how many degrees from the level to the top of B, and at the top of A to see how many degrees from the level to the top of B, know how high A is, and find how high B is. It can also be calculated by the strength of sunlight.

Now scientists have mastered a whole set of methods for measuring the distance between celestial bodies, radar measurement is measured by the propagation speed of light, and there is also a supernova measurement, which is used to measure the distance between galaxies.

It is calculated based on sunlight. Scientists calculate the distance between two bodies by counting the time it takes for light to pass through them.

There is a scientific way to probe.

First: the parallax method, which is a phenomenon that arises when people look at it from different angles on the other side of the earth.

Second, the calculation is made by comparing and analyzing the absolute magnitude of the star and the spectral intensity of the traveling star.

First of all, human observation is still based on "light", that is, electromagnetic waves, including visible light and invisible light.

Then light can't be faster than the speed of light, the speed of light seems fast, but compared to the vastness of the universe, it moves almost slower than a snail.

We use light years to measure the length of the universe, one light year is the distance of light in the universe for a year, 13 billion light years is the distance of light in the universe for 13 billion years, it is speculated that the age of the universe is about 13.8 billion years, 13.8 billion years ago the universe was born, no matter ** or others, at that moment the light A began to run in one direction, 13.8 billion years later ran to the earth, we saw the most primitive light in the universe, called microwave background radiation.

Looking up now, the sun is 8 light-years away from humans, what we see is the sun 8 minutes ago, Sirius is light-years away from the earth, we see Sirius hundreds of millions of years ago, the light that is 13.8 billion light-years away, we see the point of light 13.8 billion years ago, so assuming that the universe was really born 13.8 billion years ago, then the universe was not born 100 million years ago, and naturally there was no light, so we can't see anything.

This is the observable universe.

Now human beings are based on tens of thousands of years of science and technology, and hundreds of years of science and technology have accumulated the limit of naïve civilization.

The sun is 1.5 billion kilometers away from the earth, and the light travels from the sun to the earth in eight minutes and twenty seconds.