Yep, you would be shocked at how most people don't understand this concept. IT would also take a ridiculously powerful telescope to look at earth and be able to make out dinosaurs from 300 million light years away but hey, who am I to say what type of technology other beings could have.
However, you are a.ssuming that the speed of light between us and this alien world 300 million light years away has been constant for all this time (no black/white holes in 300 million years).
was just reading about this about a week ago while researching about the pillars of creation its amazing.
and by the way, if you had a telescope that could see onto another planet i doubt you'd be seeing in the past, youd be seeing in real time, when ur comparing the light from stars the reason it takes so long is because it has to travel from the star to you, but with a telescope your going straight there, so light is bypassed
so if u are walking around looking through a binocular, u are seeing things before everyone else?