We’ve all seen stars in the sky, light produced by suns millenia ago reaching us now, so the light produced has travelled somewhere.
As a cinema projectionist I’ve been reflecting the light produced by 2.5kilowatt, 3.5kw, up to 6kw Xenon lamps off of movie screens for 24 years. Where does the light go, where has it gone?
It doesn’t 'go anywhere. It’s still right there in the form of heat; you just can’t see it anymore.
Perhaps you’re thinking along the lines of Olbers’ Paradox? The OP is rather short and unclear.
Light that doesn’t hit anything just keeps on going. Light that does hit something either gets reflected and then keeps on going, or it gets absorbed and converted to heat.
As an excellent rule of thumb, whenever the question is “where did the energy go?”, the answer is almost always “heat”.
Which prompts the question, “Where did the heat go?”
Oh, it’s right there.
And there, and over there, and that other place…
It makes the object that absorbed it warmer. Example: earth is warmed by photons it absorbs from the sun.
Not entirely true. If the Earth retained the energy of all the photons that have reached it since it was formed 4.5 billion years ago, there would be nothing left but a smoking cinder.
The Earth looses a lot of the energy absorbed through infrared emission - wacky picture here.