Ask Ethan: Do signals degrade as they travel through space?

"Signals do change, but the act of traveling through the Universe won't lead to any sort of deterioration; just an alteration, and one we can usually account for. Here's the science of what's going on. In order to arrive at our eyes (or instruments), a signal has to go through a wide variety of environments."

"From across the distant Universe, there are many potential effects it can encounter: sources of matter and energy, fields of a variety of types and strengths, environments that change, including by gravitationally growing or shrinking over time, and even the expansion of the Universe."

Signals traveling through space experience degradation on Earth due to spreading, medium effects, and interference. Similar factors affect signals traveling across billions of light-years through the Universe. Light and gravitational waves encounter various environments including matter, energy fields, gravitational effects, and cosmic expansion. While these factors alter signals during transmission, the changes represent alterations rather than true deterioration. Scientists can generally account for and compensate these alterations to recover information about the original signal source. Understanding signal modification across cosmic distances remains essential for interpreting astronomical observations.

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