Why did earth get smaller?

Earth has not significantly changed in size since its formation over 4.5 billion years ago. However, geological processes such as erosion, volcanic activity, and tectonic movements can redistribute materials, giving the appearance of changes in size or shape. Additionally, the planet's atmosphere and hydrosphere can lose mass over geological timescales due to processes like solar wind stripping and space impacts. Overall, while Earth’s dimensions are stable, local variations can create the perception of change.