Life started exactly once in 4.5 billion years on earth. — an-salad

Do you have any links to the info you used to reach this conclusion?

That strongly implies it’s a one off event. — an-salad

No it does not.

What if we – DNA, RNA, etc – are "aliens"?

The theory of chance would beg the differ here, particularly if you are implying that aliens don't exist given the scale of the Universe.

As a single data point to provide perspective and scale - 'The Hubble Deep Field, an extremely long exposure of a relatively empty part of the sky, provided evidence that there are about 125 billion (1.25×1011) galaxies in the observable universe.'

How can you contend that life is a one-off event if we are speaking towards that number for GALAXIES, let alone stars? Interestingly, the Milky Way is among one of the oldest galaxies. By way of comparison, the Milky Way galaxy that contains our solar system is approximately 13.2 billion years old, while the universe itself has been dated at 13.8 billion years. So we are on the older side, per say.

But for further perspective, within our galaxy, our own planetary system is the only one officially called “solar system,” but astronomers have discovered more than 3,200 other stars with planets orbiting them in our galaxy.

To consider life a one off event simply defies the probability of the odds. If you keep rolling a die, with 5.4 billion sides to it, an infinite number of times, at the pace of even once per second (a joke given how chemical reactions occur at scale), to ascertain, that whether in a system with the right chemical compositions, given we already know exist from foundational chemistry, it will eventually turn up with the side that says - Life: Begin.

We just may not ever find it in existence somewhere else, reachable, to be true.

Unless we can eventually harness dark / exotic matter or create wormholes, or send a signal back from going through the event horizon of a black hole (and it actually leads somewhere, not just crushing us), or discover a way to travel faster than the speed of light, leveraging likely some type of quantum mechanics principle like quantum entanglement, the reality is we may never know because of the vast distances we are from other potential life harbouring planets, because of the vast distances in light years we are from them. Or we learn to access higher dimensions of reality that transcend physical matter - I'd vote for this if we keep evolving the right way, don't put chips in our head, and accept mortality. Or finally, if aliens actually do show up.

If we ever do, physically, it will surely be an exciting day, but there is no question in my mind that it does. We are as special and as not as we let ourselves believe, depending on perspective, and particularly Darwinian evolution in all that came, or was perhaps somewhat destined to, come next!

:up: :up:

My own take on the implausibility that "we are alone" :nerd:
https://thephilosophyforum.com/discussion/comment/380306

:rofl: