-
(Untitled)
So, yeah: if you want to crosspost comments from here to anywhere else, go right ahead. You can also reuse anything I say under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. If you ask nicely, I’ll probably grant you even more permissive licensing. -
(Untitled)
I'm not dead yet. -
Postcards from string theory, part 0
As it seems somewhat remiss to be at least nominally a physicist but to know nothing much about superstrings, I've decided to learn a bit of string theory during my lunch breaks. As the theory becomes clearer and I put the pieces together I'll write about it here. This series will be a little different to my other articles on physics: usually I ( Read more... ) -
More on relativity and causality
Someone called Teemu commented on my earlier article on "Relativity, FTL and Causality" and my answer was so long that I thought it should be a post in its own right. Among other things, Teemu said:
You say: "For any event P (where P is a label for something happening at a given place at a given time), the events within P's future light cone make ( Read more... ) -
Sharp Blue
If Livejournal should disappear unexpected, my real weblog, Sharp Blue, will continue to offer the same content. Also, if anyone would like to add me to their Facebook friends and hasn't done so, I have a Facebook profile too. -
Tweaking ReadyNAS Bonjour settings
I've been very happy with my ReadyNAS NV+ except for small two things. Firstly, it advertises its AFP shares over Bonjour using the name "AFP on Whatever" where "Whatever" is the name of the ReadyNAS, which looks ugly when it appears in a list of other devices with AFP shares. Secondly, it appears in the Finder sidebar with the generic Cinema ( Read more... ) -
Unity, disunity and continuity
This will be a much more rambling post than is usual. On the Brin List, the conversation has turned to the fundamental nature of ethics, and from there, essentially, to whether "might makes right", or at least whether ideologies that endure are de facto the most effective and so most moral. During this discussion, one of the more erudite ( Read more... ) -
The causal structure of black holes, part two
In the previous part of what has now become an ongoing series on the causal structure of various general relativistic spacetimes, I discussed the causal structure of the flat, Minkowski spacetime of special relativity, and of the Schwarzschild vacuum outside a spherical, uncharged, non-rotating star which collapses to form a black hole. In this ( Read more... ) -
The causal structure of black holes
A commenter writing about my earlier post, "Relativity, FTL and Causality" said:
As far as FTL being equivalent to time travel, the above explanation is correct. As far as FTL being impossible at present, it is not quite. Richard's explanation lacks a mention of black holes. An object (with non-zero mass), falling into a black hole from rest, will ( Read more... ) -
Integration modelling, part one
Data modelling is the art of abstracting aspects of reality relevant to a given problem and then representing those aspects in a database schema or collection of classes or other concrete form. Data modellers thus deal with deal with several different worlds simultaneously:
- The problem domain, a part of the real world (or at least a part of the ( Read more... )