I think brain-in-jar or head-in-jar are pretty underrated. By this I mean separating the head from the body and keeping it alive with other tooling. Maybe we could have a few large blood processing plants for many heads, and the heads could be connected to nerve I/O that would be more efficient than finger → keyboard IO. This seems fairly easier than uploading, and possibly doable in 30-50 years.I can’t find much about how difficult it is. It’s obviously quite hard and will require significant medical advances, but it’s not clear just how many are needed. From Dr. Brain Wonk,
Unless you do a body transplant (a serious idea pioneered by surgeon Robert White), the technology to sustain an isolated head for more than a few days doesn’t exist. Some organs essential for homeostasis, such as the liver and hematopoietic system, still have no artificial replacements… supporting organs without the aid of a living body for even brief periods of time is difficult and expensive.
So, we could already do this for a few days, which seems like a really big deal. Going from that to indefinite stays (or, just as long as the brain stays healthy) seems doable.In some ways this would be a simple strategy compared to other options of trying to improve the entire human body. In many ways, all of the body parts that can be replaced with tech are liabilities. You can’t get colon cancer if you don’t have a colon. A few relevant links of varying quality:https://www.quora.com/Is-it-possible-to-keep-a-human-brain-alive-without-its-body-If-so-how-long-could-it-be-kept-living-if-not-foreverhttps://www.discovermagazine.com/technology/could-a-brain-be-kept-alive-in-a-jarhttps://www.reddit.com/r/askscience/comments/g141q/can_a_brain_be_kept_alive_in_a_jar/https://en.wikipedia.org/wiki/Isolated_brainhttps://www.technologyreview.com/2018/04/25/240742/researchers-are-keeping-pig-brains-alive-outside-the-body/
Yes. But the head also ages and could have terminal diseases: cancer, stroke, ALZ. Given the steep nature of the Gompertz law, the life expectancy of even a perfect head in jar (of an old man) will be less than 10 years (I guess). So it is not immortality, but a good way to wait until better life extension technologies.
I was thinking of it less for life extension, and more for a quality of life and cost improvement.