Detecting light from objects that are located beyond the observable universe or beyond the cosmic event horizon is indeed an interesting concept. The key to understanding this lies in the expansion of the universe and the concept of comoving distance.
The universe has been expanding since the Big Bang, and during this expansion, light emitted from distant sources has been traveling through space towards us. However, due to the expansion of space itself, the distance between those distant sources and us has also been increasing over time. This means that the light we detect from very distant objects today actually started its journey towards us when the universe was much younger.
When we talk about detecting light from objects that are currently estimated to be 46 billion light-years away, it is not the actual distance traveled by the light that we are referring to. Instead, it is a measurement of the comoving distance. Comoving distance takes into account the expansion of the universe over time and provides a way to compare distances at different cosmic epochs.
The comoving distance is not limited by the age of the universe. It can exceed the age of the universe because it takes into account the expansion of space itself. The comoving distance to an object is essentially the distance that the object would be from us if the universe were not expanding.
To detect light from such distant sources, astronomers use various observational techniques and instruments. For example, they may employ powerful telescopes capable of capturing very faint light signals, as well as techniques like gravitational lensing, where the gravity of massive objects bends and amplifies the light from even more distant sources.
It is important to note that our understanding of the universe's expansion and the precise distances involved is constantly evolving. Measurements and observations refine our understanding of the cosmos, and future discoveries may provide new insights into the nature of very distant objects and their light.
In summary, when scientists detect light from objects that are currently estimated to be billions of light-years away, it is not the actual traveled distance of the light that is being measured. It is the comoving distance, taking into account the expansion of the universe. This allows us to observe light from objects that were emitted when the universe was much younger, even if the measured distance exceeds the current age of the universe.