That I agree with, which is why I mentioned that the 9 year timeline is likely too ambitious. But there is a difference between it being very complicated and l

That I agree with, which is why I mentioned that the 9 year timeline is likely too ambitious. But there is a difference between it being very complicated and likely relying on technology (or a fundamental understanding of something we don't know about) we don't have yet, and a "big no" and "never". Which is what this paper seems to be saying (reinforced by the comment I was replying to also saying "never"). That is the part of this that bothers me. Yeah we should admit that it is going to be very hard (if not impossible) and we should examine the reality of the timeline claims. But we should not be discouraging the research on both of these topics at this time by making claims that it will never happen.