Tag Archives: physics

Change Time

After some time trying to think about almost nothing, the last 24 hours have been an alarm call. As others come out of hibernation too, they post interesting stuff and Radio 4 provoked me with a discussion on facts and truth. Now Marc Cooper is at it, with difficult  links about computation and I’m all on Edge https://www.edge.org/response-detail/26733
Before I read about “discrete tensor networks”, I need to write down my own ideas about time, so I will know in the future what I thought, before my mind was changed.

I am ill-equipped for this task, having only 1 term of university maths to my name so I intend to talk in vague, abstract terms that are hard to argue with.

Much of physics is very dependent on Time, like almost all of computer science and business management theory. You can’t have change without time, it seems. Einstein talked about space-time, mostly in the language of mathematics. I can just about order a beer in math(s) but I can’t hold a whole conversation. I know what the first 3 dimensions are: left-right, up-down and back-forward. My personal model of the 4th dimension is that same space in continuous state-change through time. There are a few things I’m not happy about:

  • There is no evidence that time is either continuous or constant.
  • We only have evidence of time being a one-way dimension.
  • What the heck does ‘continous state-change’ mean? Is state a particle or a wave? Make your mind up, physics!
  • There’s that troubling many-worlds interpretation of the universal ‘WAVE’function (which I don’t understand either) which says that everything that might have happened did, in other universes. I don’t like this. Yes, that’s my entire justification – I don’t like the conclusion of a thought process I don’t even understand. It doesn’t feel right.

I’ve been learning about the functional programming language Clojure which does not ‘mutate (change) state’. It doesn’t have ‘variables’ like the more common imperative languages such as FORTRAN, BASIC, C, Java or Python. In Clojure, data flows through functions and is transformed from one form to another on the way. It is basically magic. In a pure functional program, no state is changed. State-change is called a “side-effect”. Sadly, side-effects are required to make a program do anything useful in the real world. Arguably, the purest magic is encapsulated in the world of mathematics and the physical world is a messy place that breaks things.

Clojure models time. It does not model the real world by replacing the current value in a variable and throwing the old value away but by chaining a new value onto the end of a list of all previous values.

Now let us extend this idea ‘slightly’ in a small thought-experiment, to a 3-D network of every particle state in the universe.

Space-time now has 2 regions:

  1. The past – all historic states of those particles as a theoretical chain of events
  2. The future – all possible future states of the universe; effectively an infinity of all possible future universes that could exist, starting from now.

Which brings us to what I mean by ‘now’ – a moving wave at the interface between the past and the future, annihilating possible future universes. Time becomes a consequence of the computation of the next set of states and the reason for it being a one-way street becomes obvious: the universe burned its bridges. Unless the universe kept a list, or we do, the past has gone. Time doesn’t need to be constant in different parts of the universe, unless the universe state ticks are synchronous but it seems likely to be resistant to discontinuities in the moving surface. I imagine a fishing net, pulled by current events.

It’s just an idea. Maybe you can’t have Time without change.

[ Please tell me if this isn’t an original idea, as I’m not very well read.
I made it up myself but I’m probably not the first. ]

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Asynchronicity Traps

Don’t you love it when lack of planning comes together?

Last Thursday, I learned about JavaScript callbacks, which reminded me of OpenVMS Asynchronous Traps (ASTs.) I learned to code in a world of single-threaded processing, so this was an advanced topic, along with my interest in occam and Communicating Sequential Processes. Back then, only real-time coders and those looking to the future cared about parallelism. I remember not really seeing the point of Yourdon ‘state-diagrams’. I’d never experienced the complex state network that a GUI with a few option buttons can generate.

Last night I came across debates about the advisability of abandoning JS callbacks for the HTML5 ‘promise’ construct; “callback hell”, they called it. Promises are functions. This is another area where the elegant simplicity of functional programming appears to offer hope. Functions are mathematical constructs, so in functional languages perhaps all possible states that code might enter can be identified.

Alongside this, I’ve been reading about research into the energy requirements of computation. For a long time, computer scientists thought that every logic operation would have a cost in terms of energy and hence entropy, but that appears not to be true. It is information deletion that costs energy, so immutable data is more energy efficient. I’m only up (down?) to quantum bits, so I’ll have to let you know how the cat gets on another day. I worry when physics starts to look like mystical religions.

Like magic, the laws of physics do not apply to software

For a few months I’ve been arguing that Agile product/service development only works for classes of systems that are not subject to gravity, like software and business processes. After attending a talk on the functional language Clojure by Paul Williams of @birminghamfp at Agile Staffordshire, I discovered this MITOpenCourseWare 6-001 introductory video.

http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-001-structure-and-interpretation-of-computer-programs-spring-2005/video-lectures/1a-overview-and-introduction-to-lisp/

I particularly recommend about the first 10 minutes. After that you may accidentally learn Lisp and I’ll deny all responsibility for subsequent brain damage if that happens. Hal Abelson argues that ‘computer science’ is not bound by the rules of physics. Like me, he sees the design of business processes and procedures being within its boundaries. Business procedures are just an attempt to implement processes on people rather than in software, sacrificing reliability for flexibility.

I agree that ‘computer science’ isn’t about computers but I think Lean & Agile methods re-take computation for science, rather than magic or engineering. I’m sticking with ‘computational science’ for now.

Many software people are frustrated by their managers’ attempts at business change. Why do organisations allow general managers with no training in the re-factorisation of complex processes to run business change programmes when they wouldn’t trust them to run a small software project? It’s the same thing, but much harder.