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
Yes but in a wierd way.
The farther light travels, the greater the degree to which its frequency slowly diminishes as its wavelength correspondingly increases. We observe this phenomenon as a redshift, the tendency of visible light to drop toward the red end of the spectrum. At some point it shifts out of visible spectrum.
Redshift measurements suggest that the energy of light emitted from far distant galaxies may drop beneath visibility within a range of from 10 to 14 billion light-years from us, depending on its frequency at source.
Most of this i got from os publishers, theres a article on the subject.
Eli5 attempt: light very slowly changes frequency. Throwing a rock in a pond will produce ripples, easily visible at first. But as the circle increases in size, the waves get smaller and smaller, until they are no longer visible. Sort of..
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