Re: Ansible
November 9, 2022
I didn't meant to write two gemlog responses today, let alone two Lisp-related ones, but here we are. I told myself I was going to write when the mood struck me and it happened to do it twice today.
From Merlin's post:
In many books there was such a device - ansible - for instant communication over interstellar distances. It allowed to transmit about 6 bits per minute.
It would be possible to try to do a la hackathon, when a socket is used by teams at a speed, let's not be sadists, about 8 bits per second. On the other side of the socket sits an script language interpreter with access to some sort of data store.
Participants need to find and upload some information through this socket faster than other teams.
This immediately reminded me of this story about Lisp being used for remote debugging on the Deep Space 1 spacecraft; just a fantastic thing to imagine doing.
So now it’s time to debug a production incident, but this isn’t code running on a server in the cloud, this code is one light hour round trip time away.
…
We had a REPL running on the spacecraft and we could interact with the spacecraft through that REPL. Now accessing that REPL was not just a matter of sitting down at a terminal typing at it because to communicate with that REPL, you had to go through the Deep Space network and deal with this hour long round trip light time.
So what the process actually looked like is we’d sit around in a conference room and scratch our heads and argue and try to decide what commands to send it, and finally come to a consensus on what batch of commands that we should send.
…
And these are huge 70 meter antennas, just enormous pieces of infrastructure. … Eventually the signal goes out of this huge 70 meter antenna and goes flying through space at the speed of light where it’s received by the antenna on the spacecraft and goes through this very elaborate system on the spacecraft where the signal is decoded and turned into bits. And eventually those bits get fed into the LISP system in exactly the same as it would’ve been if you’d been sitting there physically with the terminal typing at it.