How do scientists determine the size and volume of the sun?

With scientific instruments, it is not necessarily reliable!

Scientists rely on testing.

The color of the sun.

to measure its temperature. It's like when you heat a hot piece of iron, it turns from red to white. Similarly, the color of the sun has a lot to do with its temperature. This is because there is one.

The laws of physics. Associate the temperature of a hot object with a specific color. The amazing thing about the Shin wheel is that this law of physics does not change depending on the object being tested.

If the wood is hot enough not to burn, it will glow in the same way as an iron machine. Since the sun is a bright yellow fireball, and we know a yellow.

Luminous body. , from which we know that the temperature of the surface of the sun is 5540.

There is a thermometer called a "radiation thermometer" that can be used using satellites, and the internal temperature is calculated by scientists.

Originally, an astronomer wanted to measure the temperature of the sun's rays, so he found a concave mirror, and formed a virtual image of the sun at the focal point of the concave mirror, only the size of a coin, he found a piece of metal, and shone the virtual image on the metal block, and soon the metal softened and melted, and according to the melting point of the metal, and taking into account some other losses, it was estimated that the temperature of the sun was not less than 3500 degrees Celsius.

Later, scientists discovered that the amount of radiation of the sun is related to its temperature, so the surface temperature of the sun was determined more accurately, and in the study, it was also found that the different colors of stars are also related to its temperature, for example:

3500 degrees Celsius: orange yellow, 5000 degrees Celsius: grass yellow;

6000 degrees Celsius: yellow-white, between 7000-10000 degrees Celsius: white; Between 10,000-30,000 degrees Celsius: blue-white.

Temperatures above 30,000 degrees Celsius or higher take on an eerie blue color. The surface temperature of the sun is 6,000 degrees Celsius, so it appears yellowish-white.

Regarding the calculation of the mass of the sun, there is a definite formula, and the data used to solve the formula are already known, such as the distance from the earth to the sun au, au is the astronomical unit, an astronomical unit is the distance between the earth and the sun, which is about equal to 100 million kilometers, and the value of the gravitational constant g is also known.

The sun has no fixed volume, and its mass cannot be determined, because the sun is composed of two elements, helium and hydrogen, and thermonuclear reactions are being carried out all the time (it is the most ideal energy reaction at present, used in nuclear power plants, the world does not have to pay electricity bills, but now it can only be carried out in the laboratory, and cannot be applied to industry). The energy that erupts is tens of millions of times that of the atomic bomb), and the energy and matter are emitted in the form of the solar wind, and the mass decreases minute by minute until it dies! (But the sun is so massive that it will take tens of billions of years to see the moment of its death!)

At present, it can only be estimated, and divisors are generally used to describe parameters such as the size of the planet. The volume of the Sun is about 14.1 billion cubic kilometers, and its mass is 333,400 times that of the Earth.

The motion of the planets follows the formula of gravitational force.

where g is the gravitational constant, m is the mass of one of the bodies, the other is the mass of the other, and r is the distance between the two bodies.

by Kepler's second law.

2 t (t period).

The above is available. mrω²=mr（4π²）/t²

In addition, it can be obtained from Kepler's third law.

t r cubic; = constant k (k'contains g) the period and r can be measured by astronomical means, k'It can also be calculated by observing the operation of the third celestial body M1 by observing three different formulas, and different masses M can be obtained