A computer program is an abstraction, just as an idea, a formula, a narrative. The world cannot literally be a computer program: if it is a computer anything, it has to be hardware, by definition.

Why can't the world be a computer program? I can comprehend the idea that this universe is code running on a program on a physical computer- one created by our descendants. There is speculation that we will ourselves be able to create conscious beings in a computer program w/in 100 years or so.

I can't quite wrap my head around the concept that the universe IS a computer.

I can comprehend the idea that this universe is code running on a program on a physical computer- one created by our descendants. — anonymous66

Ancestors, rather. Unless the idea is that they invented time travel, too. (Also, if our ancestors created the computer/computer program that is the universe--what did our ancestors live in? (Not the universe, presumably, since the idea is that they created it)

Anyway, as always, the first question that pops up in my mind, almost as if it were a huge, flashing neon sign, is, "But why would we believe that the universe is a computer or computer program?"

Ancestors, rather. Unless the idea is that they invented time travel, too. — Terrapin Station

I think descendants is correct. In that case, we are imaginary ancestors.. Or computer generated versions of the creator's ancestors.

Imagine we are able to create a computer generated universe complete with conscious beings. Our scientists decide to create a reality to investigate what would happen if our history was somewhat different. So, we create a world in which our ancestors (we are their descendants) live their lives over again. So, we, the descendants, create a universe in which our (or at least versions of our) ancestors live.

"But why would we believe that the universe is a computer or computer program?" — Terrapin Station

NIck Bostrom makes an intriguing argument.

Our scientists decide to create a reality to investigate what happen if our history was somewhat different. — anonymous66

What they're actually investigating is what happens in the computer program they wrote. ;-)

At any rate, so not actually our descendants, but our imaginary descendents, too--the creators would only be our descendants in their imaginations.

I suppose we could also be totally independent of their history. So, we're an experiment to see what would happen if the laws of physics were completely different from that of the creator's universe. In that case, the creators might not even be human...

I think Nick Bostrom was just imagining our future..... He started with the idea that it is very likely that our descendants Will be able to create a universe w/ conscious beings.

One big problem that I have with Bostrom's paper is the usage of terms like "very likely," "extremely unlikely," "significant chance," etc. when in fact, there's no way to estimate likelihood for such things, as there's no data for such things.

Nick Bostrom has done some fairly involved investigations in epistemic probability, starting with his PhD thesis. That's not to say that he is right, necessarily, just that he won't throw around such terms lightly.

That's fine. but it couldn't be clearer that there is no data on whether the human species is going to go extinct, for example, to even start doing probability for it.

Now that I think about it... Davies did lay out the history of the computer. The first computers were completely mechanical... so no software. I think what Davies is suggesting is that the universe is in reality, a computer with physical parts- so more like the older mechanical computers, not a computer running a program.

I don't think there's a distinction to be had between the two. Hardware itself is programmed, and you can do the tasks of hardware within software (in fact, you need "software" to make "hardware" sync up). The distinction is more to be useful in certain contexts than some fundamental difference in a computing machine.

But either way a computer is a bunch of logical switches running on binary.