The Zeitgeist

psychedelic-physicist:

Yes what we see is from the past but we would never see the Milky Way from 5 billion years ago because we are in the Milky Way. When we see something whose light took 5 billion years to get here it’s because it’s 5 billion light years away. The Milky Way is about 100,000 light years across meaning that no matter what, if we remain in the Milky Way, everything we see will only be a maximum of 100,000 years older than how we see it.
As far as our atoms being somewhere out there this is also impossible. Consider this. One night you are looking at a galaxy 5 billion light years away and suddenly you see a Supernova explosion. That means that the explosion that you are seeing actually happened 5 billion years ago. That means that 5 billion years ago all the atoms that make up life as we know it were scattered across space. But. It took the light 5 billion years to make it all the way to us. In order for our atoms to be the same atoms as the ones we are looking at in the telescope they would have had to travel faster than the speed of light to get to our location to create us so that we could then witness the explosion. But thanks to Relativity we know that nothing can travel faster than light so that is impossible.
So to recap. No. We will never look in to space and see the exact atoms that make up us because they are already a part of us. Although something you may want to think about. That hypothetical supernova exploded 5 billion years ago. More than enough time for those atoms to combine somewhere near the explosion and then create alien life. Alien life that may be looking through their telescope right now at the Milky Way as it was 5 billion years ago. Maybe one of them saw a supernova explosion. Perhaps the same Supernova that created the carbon atoms in your right hand. And just maybe they are wondering “I wonder if there’s more life out there.”
Hope this cleared things up.