The Naked Scientists Forum
On the Lighter Side
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08/06/2006 03:30:33 »
This idea struck my mind when I was reading "A Brief History Of Time",to be specific
the concept of light cone
. The first light cone might have started from the big bang because the time started after big bang so all the event after the big bang is within the future time cone of the first event, the big bang i.e all the event hapening after the big bang is affected by the big bang. The conclusion is that every event happening in present is due to the events in past and all the
events that will happen in future = events in present + events in past
. It will be more and more complicate to predict a event in future because we will have to calculate the effect of the event in present and past, which tends to increase with time, this idea is supported by 2nd law of thermodynamics which says randomness increases with time, here randomnsee is the difficulty to calculate the affect of the present and past event on future.
Re: Defining RANDOMNESS.
Reply #1 on:
08/06/2006 04:13:29 »
You are confusing disorder with randomness.
The 2nd law refers to disorder, not to randomness as such.
Beyond that, what you are referring to about the predictability of complex systems comes under the heading of chaos, as in chaos theory.
Finally, quantum theory actually talks about true randomness, which is totally different to merely a disordered system.
Chaos theory, which deals with disordered systems, does not set an absolute limit to the predictability of a system. It assumes that if you can build a more powerful computer, you can always predict a little bit more than you can today. Quantum physics argues that beyond a certain point, no matter how powerful the computer you build, you cannot predict an outcome beyond a certain point.
Beyond the issue of physics, the degree to which a number is truly random, rather than merely difficult to calculate, becomes important when you are concerned about providing seeds for cryptographic algorithms.
Last Edit: 08/06/2006 04:30:02 by another_someone