A large number of the other technologies, such as microscopy, image processing, and computational neuroscience are driven by research and niche applications.
I was talking with someone about this a couple months ago, and as far as nondestructive brain imaging goes, it may be theoretically impossible. I forget the details of the argument, but the kind of resolution you would need to observe neurons is so high that the effective penetration of whatever signal you use to observe them is too small to see the whole brain. It was just an off-the-cuff Fermi estimate, though, so I wouldn’t bet any probability mass on it.
If this is the case, it seems to be a reasonable argument against practical feasibility. Getting someone to trust destructive imaging techniques would be a much steeper uphill battle.
EDIT: For comparison, the roadmap expects a resolution of 5 x 5 x 50 nm. Modern CT scans get 0.2 mm resolution, according to Wikipedia. Obviously there’s room for improvement, but the question is, that much?
Well, if direct scanning from outside is not possible, it’s always possible to send nanobots to scan the brain from inside. It’s also possible to freeze the person, cut the brain in small slices while it’s frozen, and scan the slices. Just two different ways of “scanning” a brain, and there are probably others we don’t even think about now.
It’s also possible to freeze the person, cut the brain in small slices while it’s frozen, and scan the slices.
This is what I referred to as “destructive imaging” above. Unless the brain is vitrified (which essentially kills any chemical data, which we may or may not need) the ice damage is going to play havoc with the scanning results. Every time you refreeze/rethaw the brain to try another scan, more of the brain gets damaged from the ice. It’s a lot riskier.
Again, I’m not saying it’s impossible, but there’s a difference between a technology possible in 2025 and a technology possible in 2060. After all, I may not live to see the latter.
It was just an off-the-cuff Fermi estimate, though, so I wouldn’t bet any probability mass on it.
I’m not sure what you mean by “bet any probability mass on it”—one of the things about probability mass is that it’s conserved… -- but there are many cases in which I’d be quite happy to adjust my probabilities substantially and/or make large bets on the basis of off-the-cuff Fermi estimates. The best reason for not basing one’s actions on such an estimate isn’t that their results are no use, but that one can very often improve them somewhat with little effort.
In this instance, the main reason I’d be reluctant to base anything important on such an estimate is that it seems like improvements in measuring equipment, and/or just measuring for a long time, might be able to overcome the problem. But if the estimate were (1) a matter of what’s fundamentally possible, (2) separated from what present technology can do by several orders of magnitude, and (3) apparently quite robust (i.e., the approximations it uses don’t look too bad) then it might be entirely reasonable to conclude from it that Pr(WBE in the foreseeable future) is extremely small.
I was talking with someone about this a couple months ago, and as far as nondestructive brain imaging goes, it may be theoretically impossible. I forget the details of the argument, but the kind of resolution you would need to observe neurons is so high that the effective penetration of whatever signal you use to observe them is too small to see the whole brain. It was just an off-the-cuff Fermi estimate, though, so I wouldn’t bet any probability mass on it.
If this is the case, it seems to be a reasonable argument against practical feasibility. Getting someone to trust destructive imaging techniques would be a much steeper uphill battle.
EDIT: For comparison, the roadmap expects a resolution of 5 x 5 x 50 nm. Modern CT scans get 0.2 mm resolution, according to Wikipedia. Obviously there’s room for improvement, but the question is, that much?
Well, if direct scanning from outside is not possible, it’s always possible to send nanobots to scan the brain from inside. It’s also possible to freeze the person, cut the brain in small slices while it’s frozen, and scan the slices. Just two different ways of “scanning” a brain, and there are probably others we don’t even think about now.
This is what I referred to as “destructive imaging” above. Unless the brain is vitrified (which essentially kills any chemical data, which we may or may not need) the ice damage is going to play havoc with the scanning results. Every time you refreeze/rethaw the brain to try another scan, more of the brain gets damaged from the ice. It’s a lot riskier.
Again, I’m not saying it’s impossible, but there’s a difference between a technology possible in 2025 and a technology possible in 2060. After all, I may not live to see the latter.
I’m not sure what you mean by “bet any probability mass on it”—one of the things about probability mass is that it’s conserved… -- but there are many cases in which I’d be quite happy to adjust my probabilities substantially and/or make large bets on the basis of off-the-cuff Fermi estimates. The best reason for not basing one’s actions on such an estimate isn’t that their results are no use, but that one can very often improve them somewhat with little effort.
In this instance, the main reason I’d be reluctant to base anything important on such an estimate is that it seems like improvements in measuring equipment, and/or just measuring for a long time, might be able to overcome the problem. But if the estimate were (1) a matter of what’s fundamentally possible, (2) separated from what present technology can do by several orders of magnitude, and (3) apparently quite robust (i.e., the approximations it uses don’t look too bad) then it might be entirely reasonable to conclude from it that Pr(WBE in the foreseeable future) is extremely small.