This is a study of the feasibility of launching an intergalactic colonization wave (and its implications re: the Fermi paradox), not a proposal that humans should do that (it would be just slightly ahead of its time for that!), or a discussion of the ethics or higher-level utility of doing so. It would be refreshing to see someone discuss the things paper actually discusses. To use early-2000s terminology, the paper's future shock level is higher than that of most HN readers, leading to rather banal discourse.
In any case, I'm fairly sure the authors agree that sending mindless automata to colonize the universe doesn't seem like a great idea. Nevertheless some alien intelligence (including an Earth-based AGI) might find it a completely reasonable, even imperative, goal.
But sentient machines or uploads (assuming for the sake of this this thought experiment that they are possible)? That's a different thing.
I guess if you're not allowed to use solar in the form of chemical potentials frozen long ago into carbon-y molecules buried underground, the second best thing is to use solar in the form of gravitational potential stored in water molecules that's constantly getting replenished because the planet just happens to work like that.
Austin Central Library has a 4.7/5.0 on 1,464 reviews on Google Maps. Of course, this is a biased sample. But, I think it's safe to say lots of people love it.
// This code originally started life as a CAM6 simulator written in C
// and Forth, based on the original CAM6 hardware and compatible with
// the brilliant Forth software developed by Toffoli and Margolus. But
// then it took on a life of its own (not to mention a lot of other CA
// rules), and evolved into supporting many other cellular automata
// rules and image processing effects. Eventually it was translated to
// C++ and Python, and then more recently it has finally been
// rewritten from the ground up in JavaScript.
// The CAM6 hardware and Forth software for defining rules and
// orchestrating simulations is thoroughly described in this wonderful
// book by Tommaso Toffoli and Norman Margolus of MIT.
// Cellular Automata Machines: A New Environment for Modeling
// Published April 1987 by MIT Press. ISBN: 9780262200608.
// https://mitpress.mit.edu/9780262526319/cellular-automata-machines/
Yes. But that's a known misfeature of C and no other language does it like that. Plus I kind of meant arbitrary byte strings where you can have embedded zeroes and thus have to know the length.
You'd probably want 'return len(str)', if this is Python?
In any case, for some applications this is indeed a great hash function. Programs like rmlint use it as part of their checks for duplicate files: if files have different lengths, they can't have the same content after all.
Any `return c` for some constant is a valid and correct hash function. It just has a lot of collisions and degenerates hash-maps to terrible performance. That was in fact my first thought when I read "simplest hash functions".
Or pad all entries with 0s to an arbitrarily long size. The 0s can be assumed, and not actually stored. Therefore arbitrarily long entries need not be shortened.
That doesn't sound so strange because the presumably the majority of visitors are going to try once or twice and then carry on, and it's actually pretty difficult to get even 25 points in this game.
There’s this thing called the Berne Convention. Countries that cooperate on copyright are going to standardize their interpretations on questions like this sooner or later.
In any case, I'm fairly sure the authors agree that sending mindless automata to colonize the universe doesn't seem like a great idea. Nevertheless some alien intelligence (including an Earth-based AGI) might find it a completely reasonable, even imperative, goal.
But sentient machines or uploads (assuming for the sake of this this thought experiment that they are possible)? That's a different thing.
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