The James Webb Space Telescope (JWST) is not capable of literally seeing into the past. However, it can observe extremely distant objects in the universe, which allows us to observe light that has been traveling for billions of years.
When we look at distant objects in space, we are actually observing the light that left those objects at a specific point in the past. Light travels at a finite speed, so it takes time for light to reach us from distant sources. For example, the light from a star located 100 light-years away takes 100 years to reach us.
The JWST is designed to observe the universe in the infrared part of the electromagnetic spectrum. Infrared light has longer wavelengths than visible light, and it can penetrate through cosmic dust and gas more effectively. This enables the JWST to observe very distant galaxies that have been forming stars since the early universe.
By observing these distant galaxies, the JWST allows scientists to see the universe as it was when the light from those objects was emitted. This effectively allows us to look back in time and study the early stages of the universe's formation. The farther away an object is, the further back in time we are observing.
By studying the light from these distant objects, astronomers can gather information about the early universe, galaxy formation, star formation, and the evolution of celestial objects over time. It provides valuable insights into the history and development of our universe.