>could we observe the past directly in some way

Yes. When we see something in deep space, light years away, we're observing that something's past, in real time.

If we look at a star that say, 100 light years away, we're watching that star as it existed 100 years ago. To see what's happening with that star at this moment in time, we'll have to wait 100 years, perhaps longer if that star is moving away from earth.