Looking at stars yesterday set me to thinking if there was such a thing as a maximum distance that light can travel…?
Clearly stars are less bright than our sun and this must be a function of their distance from us (and also their initial brightness). But these distances are absolutely, mind-bendingly huge: we can see stars thats are hundreds of millions of light years away. And they are still visible not only after huge distances but also massive amount of time.
So is light not subject to “decay” or some form of “resistance” to travel that would mean there is a limit to how far (length) or how long (time) it could travel before it becomes completely unseen?
I realise I am using analogies that would be more relevant to sound or waves in a liquid so it may just be my incomprehension of the “light” phenomena and how it works that means ive missed the point… 😀
In: Physics
Light energy itself doesn’t diminish, but the ongoing expansion of the universe means that light from distant sources becomes increasingly [redshifted](https://en.wikipedia.org/wiki/Redshift) over time (basically, ‘stretched out’ because of the movement of whatever it’s coming from), and that makes it harder and harder to detect. The energy is still there, but it’s spread out over a huge distance and very difficult to get any useful information from.
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