What are acausal blocks? In this forum post the poster (2112) writes:

It is my understanding that at least Eligius pool isn't a &quot;honest node&quot; and intentionally produces acausal blocks (or at least as close to acausal as they deem practical).

What is an acausal block? Or at least what did the poster mean by &quot;acausal block&quot;. From reading the thread I get some idea that it is something to do with messing with the timestamp of the block but don't really understand it.
Perhaps this should be a separate question but does the block miner determine the timestamp that is recorded in that block?
It allows the pool to avoid making new work for every single request. Instead, it just increments the time by a second and gives that to the next miner. Under heavy load (longpolls), Eligius might use the same work for up to 7,200 miners, meaning the last miner gets a work timestamped 2 hours into the future. This helps reduce stale shares significantly.