Category: natural history

What Was It Like When The First Humans Arose O…

What Was It Like When The First Humans Arose On Earth?

“Approximately 300,000 years ago, the first Homo sapiens — anatomically modern humans — arose alongside our other hominid relatives. It is unknown whether we descended directly from Homo erectus, heidelbergensis, or antecessor, although neanderthals, which came slightly later at 240,000 years ago, most certainly came from Homo heidelbergensis. Modern speech is thought to have arisen almost as soon as Homo sapiens did.

It took 13.8 billion years of cosmic history for the first human beings to arise, and we did so relatively recently: just 300,000 years ago. 99.998% of the time that passed since the Big Bang had no human beings at all; our entire species has only existed for the most recent 0.002% of the Universe. Yet, in that short time, we’ve managed to figure out the entire cosmic story that led to our existence. Fortunately, the story won’t end with us, as it’s still being written.”

For those of you who haven’t been following, this is now part 30 of my series on “what was it like when…” where I’ve been chronicling our natural history, from before the Big Bang up through the present day. Next week’s will be the final installment of that series, as we’ll arrive at the present!

This edition takes us from 65 million years ago to just 300,000 years ago: the development of modern humans. Come take a read; it’s the story of us all.

Ask Ethan: How Fast Could Life Have Arisen In …

Ask Ethan: How Fast Could Life Have Arisen In The Universe?

“How soon after the Big Bang would there have been enough heavy elements to form planets and possibly life?”

Making anything in this Universe takes time. After the Big Bang, there are a whole slew the Universe needed to take before rocky planets and life were possible. This includes the formation of atomic nuclei, neutral atoms, dense enough gas clouds to make stars, multiple generations of stars living-and-dying, and only then will the Universe be filled with the right ingredients to create rocky worlds and, potentially, life. But Earth didn’t come into existence until more than 9 billion years after the Big Bang, and these ingredients were around long before that. The heavy elements from the first supernovae could have made rocky, Earth-like planets very early on, but interestingly enough, it takes longer to form enough carbon to make life a reasonable possibility.

Let’s run through the Universe and find when life could have first evolved. The answer might be sooner than you think!