The theory of the earth expansion typically starts from the assumption that "Pangaea" covered a considerable part of the earth, and it was approximately 55{33106c3b400895d2b7aaa6a25acbc9ced29d72400c567cf1fa0aebeb674ff583}-60{33106c3b400895d2b7aaa6a25acbc9ced29d72400c567cf1fa0aebeb674ff583} of the current diameter. With the growing volume of the planet as a result of the endogenic procedures the continent crust broke into pieces and thus widening the gaps that were developed to oceans as they are today, it was a result of the seafloor spreading.
You find that at first the earth was molded by other condensation of the primordial gases that are located on the sun-system through the accretion of about 4.6 billion years ago. After the formation and placed on the orbit, there was constant irradiation primarily caused by the cosmic rays that resulted in the bombardment of the asteroid as well as the meteor that came in various sizes. Over the next millions of years, the earth would then proceed to form a solid crust that will have a surface. The crust thickness would increase bit by bit, and this became even bigger over time.
There was an astronomical body that had a mass of 3{33106c3b400895d2b7aaa6a25acbc9ced29d72400c567cf1fa0aebeb674ff583}-5{33106c3b400895d2b7aaa6a25acbc9ced29d72400c567cf1fa0aebeb674ff583} of the earth that crashed with the planet around 4.3 BY ago. It mainly affected the crust due to the force that was involved in the giant impact. This is typically the first enormous impact, and it has been recorded as FGI. It resulted in the partial melting of the parts of the earth, and this resulted in the ejection of materials from the face of the planet. It has been identified that part of the mass became the moon. This remains on the orbit around the earth, and this played a significant role when considering the face of the earth.
After the first giant impact, after a long while, the earth crust healed, this is after the melting occurred. It cooled off, and the thickness over the years continued to increase. The depth proceeded to raise, and this further brought about the covering of the entire earth. After a number of years, there was the growth of the vegetation and animals that started developing. The collisions that caused the bombardment never stopped, they proceeded and resulted in volcanic eruptions, changes in the climate, but the structure of the earth never changed at all. At that time the earth was referred to as the pre-proto earth, and it has significances like the mass of the planet is equal to the present earth structure, the surface area is also large compared to the land area of the current earth, and finally, SG is larger compared to the present earth section.
It has also been verified that the earth over the years has resulted in an increase in size, and this is changing in the present time. This means that the earth's volume is expanding day by day. In the solar systems, the changes are different, and this has made the expansion of the earth to be one of the unique things in the face of the earth.