5 ms·

So, I'll put this into terms that a sysadmin can understand: imagine if all the Ethernet or fiber going to a datacenter rack was bundled up, and I cut that bund

So, I'll put this into terms that a sysadmin can understand: imagine if all the Ethernet or fiber going to a datacenter rack was bundled up, and I cut that bundle up. Now you have to splice them back together so that every port is still connected to the same port it was before I cut the cables. Oh, and also, the cables are microscopic, incredibly fragile, and we don't know how to actually repair them. We sort of just hope they can grow back in place.

avg_dev 3y ago
Very clear mental image there. Thanks for phrasing it that way.
p1esk 3y ago
The fact that they grow back in place makes the whole thing 1000x easier, no?
- waste_monk 3y ago
  Imagine that the bundle of cables were all completely identical and unlabelled in any way. Even if you could surgically reconnect the nerves perfectly, you don't know which nerves should be connected to what on the other side. As another commenter posted, there are 31 "bundles" of nerves carrying a total of a few hundred thousand individual fibres. The odds of re-connecting a human spine correctly are simply incredibly small.
- itishappy 3y ago
  Only if it grows back correctly! Imagine attempting to wire up a datacenter that is actively trying to rewire itself (and not necessarily to your plans).
  - garba_dlm 3y ago
    here's the kicker it's all connected to an organic deep neural network which means that the specific arrangement of the physical wires doesn't matter. because there's a training period in which the neural network literally learns to control the body anyways
    - dotnet00 3y ago
      Except the arrangement starts to matter more and more with age.
      - garba_dlm 3y ago
        [flagged]
    - chairhairair 3y ago
      If we only ever wanted to reconnect nerves of fetuses that might be relevant.
      - knome 3y ago
        There's no reason to be glib. If patients' brains can reconfigure following trauma such as strokes [1] or having our entire visual field flipped [2] there's no reason to assume one couldn't reroute around having nerves hooked up differently. [1] https://www.ncbi.nlm.nih.gov/books/NBK326735/ https://www.ncbi.nlm.nih.gov/books/NBK326735/ [2] https://www.theguardian.com/education/2012/nov/12/improbable-research-seeing-upside-down https://www.theguardian.com/education/2012/nov/12/improbable...
        tsavo 3y ago
        Can speak from personal experience. Traumatic incident which severed the nerves to my leg in multiple places. Nerves eventually regrew and reconnected within the leg, and then again where they were severed in the foot. Motor and senory nerves reacted differently. When motor nerves reconnected, I still couldn't contract the muscles and went through a series of steps to relearn how to use the limb. First I was trying to "move" the leg, but effectively the "IP address" for the leg was changed so my "move" signals were going to where my head thought the leg was instead of to the new connection. Instead, I would estim a specific muscle and "listen" in my head for where "noise" was coming from. That "noise" was the electric buzzing from the estim'd muscle contraction. Eventually, I learned how to concentrate to make a muscle contract, and many steps later (pun intended), I learned to walk again. Sensory nerves didn't need a push signal, they're like a constant inbound feed when connected. When the sensory nerves reconnected, it is something you definitely notice. Going about your day, and suddenly you feel an jolt, like being shocked, and over the next few hours to days the area that is reconnecting is burning, stinging, feels like it is being crushed by pressure, and cold all at the same time. It was much more intense than when your arm falls asleep. The sensation can be maddening but it eventually passes as your body begins to sort and acclimate the signals. All of these steps on calibrating the sensory nerves and learning how to contract and coordinate muscles is something we take for granted as people usually sort it out when they're infants.
- 2devnull 3y ago
  No.
- inglor_cz 3y ago
  Unless they get weird and turn cancerous, or some kind of strange Ethernet-eating bug attacks and eats them etc. Regenerative medicine of living tissues is extra hard.
londons_explore 3y ago
For scale, a human spine has coming off it a few hundred thousand nerve fibers inside 31 pairs of nerves.[1] I was actually expecting more, since that is effectively IO for the whole body, and each individual nerve fiber tends not to fire more than tens of Hz. [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4612209/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4612209/
- rbanffy 3y ago
  Not the whole body. Eyes and ears have their own high bandwidth direct attachment interfaces to the cortex.

avg_dev 3y ago

Very clear mental image there. Thanks for phrasing it that way.

p1esk 3y ago

The fact that they grow back in place makes the whole thing 1000x easier, no?

waste_monk 3y ago
Imagine that the bundle of cables were all completely identical and unlabelled in any way. Even if you could surgically reconnect the nerves perfectly, you don't know which nerves should be connected to what on the other side. As another commenter posted, there are 31 "bundles" of nerves carrying a total of a few hundred thousand individual fibres. The odds of re-connecting a human spine correctly are simply incredibly small.
itishappy 3y ago
Only if it grows back correctly! Imagine attempting to wire up a datacenter that is actively trying to rewire itself (and not necessarily to your plans).
- garba_dlm 3y ago
  here's the kicker it's all connected to an organic deep neural network which means that the specific arrangement of the physical wires doesn't matter. because there's a training period in which the neural network literally learns to control the body anyways
  - dotnet00 3y ago
    Except the arrangement starts to matter more and more with age.
    - garba_dlm 3y ago
      [flagged]
  - chairhairair 3y ago
    If we only ever wanted to reconnect nerves of fetuses that might be relevant.
    - knome 3y ago
      There's no reason to be glib. If patients' brains can reconfigure following trauma such as strokes [1] or having our entire visual field flipped [2] there's no reason to assume one couldn't reroute around having nerves hooked up differently. [1] https://www.ncbi.nlm.nih.gov/books/NBK326735/ https://www.ncbi.nlm.nih.gov/books/NBK326735/ [2] https://www.theguardian.com/education/2012/nov/12/improbable-research-seeing-upside-down https://www.theguardian.com/education/2012/nov/12/improbable...
      - tsavo 3y ago
        Can speak from personal experience. Traumatic incident which severed the nerves to my leg in multiple places. Nerves eventually regrew and reconnected within the leg, and then again where they were severed in the foot. Motor and senory nerves reacted differently. When motor nerves reconnected, I still couldn't contract the muscles and went through a series of steps to relearn how to use the limb. First I was trying to "move" the leg, but effectively the "IP address" for the leg was changed so my "move" signals were going to where my head thought the leg was instead of to the new connection. Instead, I would estim a specific muscle and "listen" in my head for where "noise" was coming from. That "noise" was the electric buzzing from the estim'd muscle contraction. Eventually, I learned how to concentrate to make a muscle contract, and many steps later (pun intended), I learned to walk again. Sensory nerves didn't need a push signal, they're like a constant inbound feed when connected. When the sensory nerves reconnected, it is something you definitely notice. Going about your day, and suddenly you feel an jolt, like being shocked, and over the next few hours to days the area that is reconnecting is burning, stinging, feels like it is being crushed by pressure, and cold all at the same time. It was much more intense than when your arm falls asleep. The sensation can be maddening but it eventually passes as your body begins to sort and acclimate the signals. All of these steps on calibrating the sensory nerves and learning how to contract and coordinate muscles is something we take for granted as people usually sort it out when they're infants.
2devnull 3y ago
No.
inglor_cz 3y ago
Unless they get weird and turn cancerous, or some kind of strange Ethernet-eating bug attacks and eats them etc. Regenerative medicine of living tissues is extra hard.

londons_explore 3y ago

For scale, a human spine has coming off it a few hundred thousand nerve fibers inside 31 pairs of nerves.[1] I was actually expecting more, since that is effectively IO for the whole body, and each individual nerve fiber tends not to fire more than tens of Hz. [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4612209/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4612209/

rbanffy 3y ago
Not the whole body. Eyes and ears have their own high bandwidth direct attachment interfaces to the cortex.