At its core,

[oskar]

I find the simulation argument pretty convincing. The only footnote I would add is that maybe a civilization advanced enough to create such a simulation would deem it pointless. But it's also conceivable that we could reach that point technologically without gaining much insight in the nature of the universe.
An interesting thought is that there will be a species on a planet a billion years from now when the universe has expanded to the point where there is no cosmic background radiation and everything is so far apart that they will look up into a black night sky and all they know about the universe is within their solar system. What image of the universe will they have? The point is that these guys might be tempted to go down the simulation rabbit hole, so there's always that. Another good point which I claim my own is that the deeper you would go down the layers of simulations of simulations the more simple, the less complex it gets. The stupider, the uglier it gets. Looking out the window I can imagine that this world is pretty far down that hole.

I've heard Daniel Dannett present the fact that decisions are finalized in our brain before we realize it as evidence against free will, but I'm not sure I find that all too convincing. What I do believe is that we have much less autonomy than we would like to think we have and we would be better off acknowledging that, but on the other hand a purely deterministic world view could be dangerous, especially to purely deterministic beings, so let's better keep our greasy fingers off that pandora's box imho.

[MadMojoMonkey]

An interesting thought is that there will be a species on a planet a billion years from now when the universe has expanded to the point where there is no cosmic background radiation and everything is so far apart that they will look up into a black night sky and all they know about the universe is within their solar system. What image of the universe will they have?

Way more than a billion. The sun will still be burning in a billion years. It'll have expanded to larger than the size of Earth's orbit, as it will be in its red giant phase, but it'll still be here.

There will always be CMBR, but it is ever more red-shifted over time, such that detection will eventually be impossible.

Assuming that the acceleration due to dark energy that we observe today remains constant or decreases:
They will see the stars in their galaxy. Also, they will see the galaxies in the neighborhood they reside within their galactic supercluster.

Dark Energy is so weak that it only acts over ludicrously long length scales. Galaxies are gravitationally bound together into clusters and those clusters are bound into superclusters. Only on length scales greater than this does the accelerated expansion overpower gravitational acceleration of attraction.

It's not too dissimilar to talking about the electromagnetic forces compared to the gravitational force. On particle scales, gravity is negligible. The dominant forces are orders of magnitude greater, so while gravity's effect isn't truly 0, it's not causing any bad predictions to ignore it. Move out to big enough scales, though and the electromagnetic imbalances average out and you are left with "large" objects which have effectively 0 electric charge, so they don't interact via electromagnetic forces, and the weaker force of gravity expresses dominance.

[oskar]

Way more than a billion. The sun will still be burning in a billion years. It'll have expanded to larger than the size of Earth's orbit, as it will be in its red giant phase, but it'll still be here.
...

Ok that's interesting. and disappointing. I guess what I'm remembering was someone talking about the CMBR and how much it would suck for astrophysics if you couldn't see it anymore.