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Just because the universe is relativistic doesn't mean that we can't model it. Mathematics is inherently immutable --- this is why describing programming langua
by bollu 7y ago
Just because the universe is relativistic doesn't mean that we can't model it. Mathematics is inherently immutable --- this is why describing programming language semantics requires the introduction of something "extra" (a state monad, hiding the mutability inside the operational / denotational semantics, whatever).
We _do_ have a mathematical model of the universe --- the differential equations that govern space-time evolution describe the universe in a pure fashion: universe(t+1) = f(universe(t)).
- dnautics 7y agoNo, you're missing the point. There is no such thing as world(time), but there is world(location, time). If you don't respect that, you'll wind up with unsustainable system designs like using atomic clocks to guarantee consistency.
- k__ 7y agoI think the problem here is the definition of "time". You are talking about a relativistic time and they are talking about an absolute global time. I don't know if it makes sense in some kind of way to talk about something abstract as a global time in any way. If the global absolute time goes on for 1 second, some peoples relativistic time went on more or less than a second. Can we measure this abstract concept of time? Even if it made some kind of philosophical sense?
- dnautics 7y agoRelativistic time is a real thing in distributed systems, even without worrying about einsteinian relativity; the premise of physics relativity is that perfect synchronization is impossible and that is highly analogous to the impossibility to perfectly synchronize nodes in a distributed system.
- senderista 7y agoThere is a nice analogy between causal relations in special relativity and in asynchronous distributed systems, but it is no more than an analogy. Synchronized clocks are a physically feasible possibility in every realistic distributed system I’ve seen. The difficulties are merely of a technical nature.
- dTal 7y agoThe effects of relativity are non-negligible in GPS, which is essentially nothing but a distributed system on synchronized clocks.
- dnautics 7y agoSure, you can get sufficiently close, and at what cost in terms of developer effort and physical infrastructure? Not everyone is Google, and in most cases if you explicitly have code that doesn't assume synchronicity you will avoid footguns that inexperienced devs will make.
- int_19h 7y agoThat's exactly the point - there's no such thing as "absolute global time".