Consciousness wants to live forever because it can't conceive of a world in which it doesn't exist - the thought is unthinkable and the idea is frightening. Brain uploading seems like a solution to that problem, until you realize there's no reason to assume that the uploaded copy once made is me any more, and any number of excellent reasons to assume it isn't.

How do you know that you are not now, a simulation? In fact, once we have the technology to produce such a simulation, logically speaking, then, it is an overwhelming probability that we are a simulation, given that, you have at most one 'original' creature, and each subsequent creature can (eventually) create an artificial universe with artificial beings, for some definition of artificial. Thus you have (n-1)/n chances of being a simulation, which over time, as n-> infinity, means a certainty.

Even our reasons for thinking we are 'real' are flimsy. We say we have our senses! We open our eyes and see a blue sky and green grass. We reach down and touch each individual blade of grass, surely not a simulation.

But even that is bogus. There is no such thing as a blue sky, or green grass. That's all in your head. It's (at most) just different frequencies of energy. Same goes for this 'touching' bit. You don't touch anything, you just (again at most) have energy interactions.

So get used to it, you likely are a simulation.

I suspect people who believe in the "life is a simulation" have little experience in running molecular dynamics simulations. Even simulating a single protein for a few microseconds takes a Linux cluster hours. The size of a computer that could simulate every protein on earth (let alone every other type of molecule) would be literally astronomical (as in larger than a planet; and no, plausible improvements in technology really wouldn't shrink that by much). Simulations of things like cities work because all the details of molecules and cells aren't simulated. But we can measure all these things, so either the simulation we are in is really that detailed, or, more plausibly, we aren't in a simulation.

Modern video game engines vary the detail with which objects are rendered depending on distance, throwing away imperceptible details of faraway objects in order to free up processing resource which can be used to increase detail for things near enough to show the difference. In the newest generation, the transitions between various levels of detail are effectively imperceptible. So what if the details of molecules and cells are only simulated when we're paying attention?

"Life as a simulation" theory doesn't really concern itself with plausible technology, any more than space opera does, and yet there are people who take both seriously and in at least some part model themselves on that basis. Plausibility doesn't really seem to be their major concern.

how feasible something is, is irrelevant to this post. Ok, not feasible now. I'll come back in 100,000 years. Is it feasible then? If so then the logic still holds.

I'm talking feasibility ever. The absolute minimum hardware needed even in 100,000 years to simulate an atom in all its complexity would be more than one atom. So it would as infeasible as making a map larger than the territory.

Whether "I" runs on a Baudrilliard machine is orthogonal to whether a copy of "I" is still "I" to "I" - and why would it be, with no shared sensorium? - which is the point I'm making.

Elementary indistinguishability is orthogonal and I'd like to say it's kinda basic for the level at which this conversation is operating, but there's so many unexamined assumptions and so much consciousness chauvinism flying around in here, who knows what's too basic to be worth mentioning.

Jeron Lanier has an interesting essay. He started with MIDI files, they are digital representation of music, which is mostly good enough for our ears, but not identical to the real music. Even HD audio can only sample at some KHz, so it is still discrete and not analog. How will computer representations of the brain be the same as the human brain, and how will it differ?