Scientists claim that if an alien 65 million light years away views Earth through a powerful telescope, he can see “dinosaurs”. How can it be possible?

If at this moment in your present time someone from another galaxy has the ability to observe the Earth from 65 million light-years (our galaxy is only 0.1 million light-years) they will effectively be receiving photons or signals from Earth when in this just the Cenozoic began (the end of the age of the dinosaurs or Mesozoic).

It would take a kind of technology unimaginable to us for them to appreciate individual dinosaurs. In fact, the most distant object that has been observed from Earth is the galaxy GN-z11(z = 11, refers to the red shift it presents, which gives us an idea of ​​its distance). By our calculations right now we see it as it was about 13.4 billion years ago (a mere 400 million years after the universe was created). We do not see many details of GN-z11 and we are certain that what little we can see must be noticeably different from how GN-z11 is today. In fact, due to the expansion of the universe at the moment, the space between us and GN-z11 is expanding at a rate higher than the speed of light, so the light that is coming out of GN-z11 right now will never reach us. . In a few million years GN-z11 will get dimmer and dimmer and eventually it will vanish from our view because due to the expansion of space the photons that came out of it will never reach us. What we see now is because those photons came out of GN-z11 when the space was much smaller and the expansion was smaller. This is one of our best “current” photos (actually from 13.4 billion years ago) of GN-z11: