The geophysics Laboratory of Sichuan University, together with Beijing high pressure research center and American scientists, re estimated the age of the earth’s solid core, and estimated its age between 1 billion and 1.3 billion years. < / P > < p > the team spent two years squeezing laser heated iron samples between two diamond anvils to create an environment similar to the earth’s core. The researchers say this age is at the smaller end of the previous estimated age spectrum of 1.3 billion to 4.5 billion years; but it is larger than the latest estimate of only 565 million years old. More importantly, the latest research will help scientists determine the heat flow of the earth’s core and the source of energy that powers the earth’s dynamo. Zhang Youjun, an associate professor at Sichuan University, explained that the core of the earth is mainly composed of iron, which is divided into a solid core and a liquid outer core. The high-temperature iron core transfers heat through heat transfer into the mantle. Therefore, the thermal conductivity of the core is the key to determine many properties of the core, including how the inner core is formed and how the “earth dynamo” is driven. “Earth engine” refers to the movement of the charged iron rich liquid outer core, which produces the earth’s magnetic field. Zhang Youjun said: “the liquid metal flow in the outer core, the difference of temperature and pressure produces electric current, coupled with the rotation of the earth, can create large-scale ‘generator effect’. The earth dynamo is the mechanism to maintain the earth’s magnetic field, which can keep the compass pointing and protect life from harmful cosmic rays < / P > < p > the newly measured thermal conductivity of iron in the core environment is lower than 30% to 50% of the recent research estimates, but this is enough to change scientists’ understanding of the earth’s age and the earth’s dynamo. The results show that the main energy sources and mechanism maintenance of the earth dynamo are thermal convection and component convection. In the early days of the earth, the earth’s dynamo was only maintained by thermal convection; since the formation of the earth’s core, these two mechanisms work together and are equally important. < p > < p > < p > “in this study, the electrothermal transport properties of iron, the main component of the earth’s core, have been determined experimentally and theoretically, and the controversy over the thermal conductivity of the earth’s core in the past 20 years has been solved,” Zhang stressed. “The earth is unique in the solar system because it has a magnetic field and is habitable,” said Professor Lin Junfu of the University of Texas at Austin, co-author of the study < / P > < p > the researchers said that since there are about 10% light elements in the core in addition to iron, they plan to further determine what effects these light elements will have on the core’s heat conduction and the earth’s dynamo. With the improvement of understanding of electrothermal transport, researchers can more accurately estimate the age of the earth’s core. It is reported that this research has been funded by the National Natural Science Foundation of China, the natural science foundation of the United States, and the construction of double first-class universities of Sichuan University. < / P > < p > the earth is currently the only home of human beings in the universe. Do we know enough about it? Not necessarily. Taking this study as an example, the ages of the earth’s solid core obtained from different studies are different, indicating that there is still some controversy among scientists. There are many similar deep-seated scientific problems, some have no answers, some are just hypotheses, and some are still inconclusive. Therefore, as human exploration continues to march into the depths of the universe, we also need to pay more attention to the depths of the earth and explore the scientific mysteries hidden under our feet. The report shows that the number of app store purchases soared in the first half of this year due to the impact of covid-19