The concept of "seeing the edge of our universe" is a bit complex, as the universe is vast and expanding. Additionally, there are certain limits to our observational capabilities. However, I can provide some information on the size requirements for telescopes to observe distant objects in the universe.
The observable universe, which is the portion of the universe we can potentially see given the age of the universe and the finite speed of light, is estimated to have a radius of about 46.5 billion light-years. Keep in mind that this does not mean the universe is a sphere with a defined "edge," but rather it represents the maximum distance from which light has had time to reach us since the Big Bang.
To observe objects at such extreme distances, we require telescopes with large apertures (the diameter of the primary mirror or lens). The larger the aperture, the more light-gathering power and resolution a telescope has. This allows us to see fainter objects and capture finer details.
However, even with a very large telescope, there are limitations to how far we can observe due to various factors, such as the expansion of the universe, the dimming of light over vast distances, and the background noise from other sources.
To see extremely distant objects, such as those near the "edge" of the observable universe, astronomers rely on a combination of telescopes and observational techniques. These include space-based telescopes like the Hubble Space Telescope, which is not limited by the Earth's atmosphere, and ground-based telescopes equipped with adaptive optics to compensate for atmospheric distortion.
Currently, there are plans for even larger telescopes that could provide significant advancements in observing the distant universe. The James Webb Space Telescope (JWST), set to launch in late 2021, has a primary mirror with a diameter of 6.5 meters (21 feet) and is designed to observe the early universe, studying the formation of galaxies and stars.
In the future, projects like the Thirty Meter Telescope (TMT) and the Giant Magellan Telescope (GMT), both ground-based observatories with extremely large mirrors, aim to push the limits of our observational capabilities even further.
It's important to note that while larger telescopes enhance our ability to observe distant objects, there are still fundamental limits to how far we can see due to the nature of the universe and the constraints of physics.