It is easy to imagine human thought freed from bondage to a mortal body — belief in an afterlife is common. But it is not necessary to adopt a mystic… - Max Tegmark

As the ancient Greeks replaced myth-based explanations with mechanistic models of the Solar System, their emphasis shifted from asking why to asking how.

Since we don’t want to limit our thinking about the future of life to the species we’ve encountered so far, let’s instead define life very broadly, simply as a process that can retain its complexity and replicate. What’s replicated isn’t matter (made of atoms) but information (made of bits) specifying how the atoms are arranged. When a bacterium makes a copy of its DNA, no new atoms are created, but a new set of atoms are arranged in the same pattern as the original, thereby copying the information. In other words, we can think of life as a self-replicating information-processing system whose information (software) determines both its behavior and the blueprints for its hardware.

Here... is the Schrödinger equation [<math qid=Q165498>i \hbar \frac{d}{d t}\vert\Psi(t)\rangle = \hat H\vert\Psi(t)\rangle</math>]... and what it's actually saying is that the state of the world, that's this Greek letter Ψ there with the bracket around it... It's saying that the rate of change of it... depends on the current state of the world, when you do this operation on it and for the math nerds, this is a linear operation... and what that just means is, as Everett has pointed out and many others have known for a very long time is that, in some circumstances, two different solutions to this can do their parallel thing. We can talk at... length about the discoveries... about decoherence and why it is that sometimes these different parallel branches are unaware or each other, but my point is... if you give a science nerd colloquium... at a physics department... ideally, you should also start in the same way you start discussing this with your grandma. Just at a very high level... here are the cool ideas, and then you can go as deep as the audience or the listener wants, from there.