When asked if he had the opportunity to travel back in time, Carl Sagan has said he would visit the legendary library of Alexandria, 2,000 years ago. There, he would encounter all the accumulated knowledge of the ancient world, now lost forever. He chose the Alexandria library because he would be able to read its scrolls and fill many historical gaps about human civilization, solving several mysteries of the past and contributing to understanding conflicts of our time.
Allyson Moutri, PhD. answered : I would prefer to go back 40,000 and meet our extinct human ancestral. Just over 150 years ago, the first fossils of our closest relative, the Neanderthals, were discovered in Germany. From analyzing these bones and comparing them to ours, we could make an accurate depiction of what the Neanderthal might look like, when their lineage split from our own, and when they went extinct - about 30,000 years ago. They were stronger than us, lived in small societies, have some kind of culture and empathy for their loved ones. Their brains were about the same volume as modern human brains. But the fossils cannot tell what was on their minds or how was their personalities.
And you what time you prefer visit if you had the opportunity to travel back in time ?