Dork Scratchings

In my previous post  Building a tensegrity structure I implied that when the thread was pulled taut an icosahedron would form.  I didn't directly use the word "icosahedron" but I did claim that you needed to allow enough thread for a stick length to triangle edge ratio of $(1+\sqrt 5)/2$, which amounts to the same thing.

 My latest project   This turned out to be a bit more fiddly than I expected.  This is partly because I set myself the goal of building it using a single piece of string and it wasn't entirely obvious how to do that without missing or repeating some edges.  Here are my tips:   1. Cut 6 pieces of bamboo Obviously these should all be the same length.  Hollow them out before going any further. 2. Measure out the thread The thread will pass through each bamboo 4 times, plus there are 24 edges between bamboo ends.  The bamboo sticks are $(1+\sqrt 5)/2$$^{[\text{see footnote}]}$ times the length of the edges (i.e. the golden ratio!)  You will need a bit more than this to make it easier to tie the ends.  Place two marks on the thread with a pen to identify where the knot should fall.   3. Blue tack the bamboo pieces in place This means creating a ball of blue tack and attaching 3 parallel pairs of bamboo to it in such a way that each pair is at...

This is perhaps the greatest epiphany of my life.  The moment I realized how to neatly summarize my understanding of the science I was learning: Time does not exist. Of course, this is just an interpretation, and a personal one.  It may not be true but in it's defence I assert it is consistent with many physicists' view of the world (though they may put it a different way).  It may not even make sense to ask whether it is true or not: what does it mean to say that a thing we don't understand, and haven't clearly defined, doesn't exist.  But like a lot of ways of thinking about reality, the real question is: Is this helpful? The things we know exist in the world can be divided into two categories: those for which we have direct evidence, and those for which we have indirect evidence.  In the former category we have light, sound, touch, smell; in the latter planets, atoms, and waves.  Time also belongs to the latter category.  We think about the future w...

 

  Time series showing the decline of growth in advanced (or "fully grown"?) economies since the 1960s suggesting an end to growth within one generation.  Growth in developing economies increased enormously between 1990 and 2005 but is now showing the same trend towards zero as advanced economies suggesting the entire world is hitting the same resource limits.  This graph took me 10 minutes to plot using publicly available data, but the obvious conclusions for the feasibility of long term growth are beyond the imaginations of almost all political leaders today.  Are we in the midst of a societal-scale shared delusion? Which do you want first...? Let's start with the bad news.  The bad news is that growth in industrialized, high income economies has been falling for the last six decades and looks like it will reach zero sometime within a generation.  (That's assuming it hasn't already reached zero with the positive growth figures that countries report...