Anyway we know that information processing can occur in non-biological, non-chemical systems, e.g., computer chips. Moreover, even though different programs on my computer aren’t divided into disjoint physical containers that doesn’t prevent them from being logically isolated. Anyway the suggestion wasn’t that chemical life isn’t the most probable way for life to evolve but that sufficently advanced aliens would learn to simulate their mental processes on computers.

Near death experiences don’t really show anything about consciousness or brain processes. Since people can REPORT their near death experiences to others they must affect the brain at some point so the person reporting the experience sends the right signals to their mouth and throat to speak. The two explanations then are either that during the time they were near death changes occured in their brain (just because they don’t have measurable EKG activity just means they lack large scale organization of their brain not that individual neurons aren’t firing) or that if we looked closely enough we would see chemicals violating the laws of physics in the brain so the soul could convey it’s memories to the jaw muscles.

Note, to explain near death experiences it’s really irrelevant whether they are brain dead or not. During that time without oxygen various forms of damage and chemical buildup can occur that could easily lead to false memories. Also it’s impossible to tell whether the people who had the near death experiences really had them while they were brain dead (probably wrong use of term) or slightly after or before.

Well intelligence is more or less generalized problem solving ability (my dictionary defines it in terms of ability to acquire and apply knowledge and skills). Dolphins (even if given prosthetic arms) can’t invent tools to let them survive on land the way we can for the sea (scuba) not to mention being unable to infer complex abstract patterns (do number theory problems). This is true even when we motivate them with rewards to try to learn math (if you don’t think they are trying use heroin/cocaine to motivate a dolphin to learn calculus and go get a nobel). Thus it’s pretty clear that dolphins simply don’t count as intelligent in the relevant sense (they don’t have the same general problem solving ability our species does). It doesn’t matter if this is because the lack of opposable digits eliminated the evolutionary pressure for intelligence or not.

Still perhaps you might worry that there was some species out there that could invent spaceships and do advanced math but chooses to live simply. However, an intelligent but non-technical species is unstable. Using gadgets will give you a reproductive advantage thus relatively quickly any such species will give up their abstract philosophizing for applied invention. Conversely if they lack the ability to construct gadgets like one might think dolphins do they will evolve to conserve energy by eliminating the reproductively unhelpful brain functions.

If the beings aren’t going themselves time dilation is irrelevant, what they would care about is time until they recieved word back. Moreover, you need to keep in mind the fact that out in the low energy regions in the hicks computations will take place more slowly so subjectively going out on such a search would require living in slow motion compared to the rest of your civilization.

But leaving this aside why would aliens want to find the primitive life forms who hadn’t yet migrated to the high energy/computation regions? If they want to find interesting aliens they look in other high energy locations. Life forms that still lived in the outer darkness would be to them the way small dumb monkeys are to us.

What I’m suggesting is that the most efficient stuff to make life out of is the high energy interactions that occur near massive black holes, neutron stars and the like so it can’t just be carried around with you.

Hmm, actually this seems like it has the makings of a genuine puzzle in philosophy of probability. This is hard and I need to think about it a bit more.

Alternatively perhaps you merely meant that this only provides weak evidence in comparison to our direct estimates of our survival probability. I dunno if I buy this since we are so bad at guessing what the future is likely to bring anyway.

In any case I wasn’t so much intending to endorse this argument as summarize it before attacking the assumptions it relies on.

Similarly, certain extinct species, like raptors, appear to have had large brains in relation to body mass. They may have been quite intelligent, but there is no evidence that they developed technology.

Accordingly, it does not appear that the debate is about finding “intelligent life”. Rather, it is about finding life intelligent enough to develop technology equivalent or superior to 20th century Earth in terms of electro-magnetic based communication systems. That life may be the dim bulb in the chandelier, but motivated and bright enough to develop technology to survive, and lucky enough to have survived long enough to do so. That raises very different issues than those raised by either side of the argument.

For aliens, I think while the best part of them might inhabit a computationally rich physical system, they could easily have poor cousins (imagine scout robots) looking for other lifeforms etc.
Anyway – at the speed of light time dilation would kick in and it wouldn’t be that boring.

I suppose by the time they would reach us they would be constructed of whatever was the most efficient material to design life.