Tuesday, September 22, 2015

Morning walk in Paradise...

Morning walk in Paradise...  We (Miki, Race, and I) left a bit later than we generally do, and went a bit further along a new route.  This took us over a “dry hay” field, which you can see in the last two photos below (with two cute dogs!).  The locals call any unirrigated field planted with alfalfa or grass a “dry hay” field.  Usually these are fields that are impractical to irrigate, either because of their steepness or because they're too far from any source of water.  In this case, neither applies; the slope is gentle and an irrigation canal runs along the field's eastern border.  The density of the alfalfa plants suggests that at some point in the past this field was irrigated, but either the owner lost water rights or his interest, or it wasn't economically viable.  It hasn't been cut this year at all, and the only grazing on it has been from deer and elk.

The first two photos show a beautiful irrigated alfalfa field that's quite close to the dry hay field.  This field has been cut, raked, and baled twice this year already – and will most likely be cut this week for the last time this season.  This hay goes to a dairy a few miles north of us, and they've collected a lot of hay this year.

We saw several hawks this morning, but nothing like the hawk density of the past few weeks.  We also see no voles any more, and I suspect the former is caused by the latter.  Something we did see in abundance: a small, yellow-green butterfly.  They are everywhere in the fields.  My beloved sunflowers are done for the year, I'm sure to the relief of my readers who have put up with 10,000 photos of them :)


Brotli: a new compression algorithm...

Brotli: a new compression algorithm...  It's just announced from Google, it's open-sourced (in C; look in the “dec” and “enc” directories), and there's a draft IETF standard.  I haven't looked closely at it, but from their announcement it certainly sounds interesting...

Networks of trains and other things...

Networks of trains and other things...  This article is talking about (and bemoaning) the chaos on the Internet of Things (IoT) right now.  It's certainly true that at the moment there is a mish-mash of incompatible devices, APIs, and data formats.  I'm not worried about that, though – from that chaos, I'm confident that useful standards will emerge.  The crowd of early adopters will make that happen as they figure out what things really work, which don't, and which are most useful (or make the most money).

This has happened before, and even with networking.  Back in the '70s and '80s, when the Internet as we know it was just emerging, there was chaos in the world of networks.  Conflicting network protocols, data formats, and even hardware abounded.  The advent of Ethernet 10baseT and the IP protocol changed all of that.  Virtually everything else is gone from local area networks (LANs) today, and that pair of standards rules the world of LANs. 

Something similar happened in the 1800s with trains.  When trains were first developed, every manufacturer and even buyer would make up their own gauge (the distance between the rails), weight standards, etc.  This created all sorts of chaos, and spawned new businesses that transferred cargo from train cars of one gauge onto train cars of another.  A lot of ingenuity and capital were invested in these systems, until it finally dawned on the railroads that things would be much better for all concerned if they standardized on a single gauge so that railroad cars could go anywhere in the U.S.  Once accomplished, this completely eliminated that crazy set of businesses that were moving cargoes between incompatible railroad cars.  Today we'd say that was obvious, but it wasn't so obvious at the time – plus it looked prohibitively expensive and time-consuming to accomplish. 

A little earlier there was yet another example, this time with nuts and bolts.  Every manufacturer used to have their own set of diameters and thread pitches for nuts and bolts.  If parts from two manufacturers could work together, that was a miraculous accident.  The manufacturers had all sorts of fanciful justifications for why their diameters or thread pitches were better, but that was mostly nonsense.  In this case, it was the users of nuts and bolts who drove the adoption of a standard.  The users worked together to define a standard, then told the manufacturers that they'd only buy nuts and bolts that met the new standard.  Almost overnight, the world of nuts and bolts converged on that new standard.

The same sort of thing is bound to happen with the IoT.  Well, there's one other possibility: we'll collectively decide that the IoT is a useless waste of time.  I don't think that's very likely, though...

Shadows on Mars...

Shadows on Mars...  I was browsing through some recent photos from the Curiosity rover on Mars, and this one caught my eye.  There are two places in the photo where you can see a sharp shadow of a rock.  It's the shadows that I found interesting, precisely because they're so sharp – very little of the penumbra (the fuzzy edge) that we see with shadows here on Earth.  Why is that?

It's because Mars is further from the sun than Earth is, and therefore appears to be smaller.  Penumbra happen because the source of light isn't a perfect point, but instead is a circle of perceptible size (you see the sun as a bright circle in the sky, not a single point).  The sun's angular size from Earth is about 0.5° – and from Mars it's about 0.35°.  That means that the sun, as seen from Mars, is just over half the size in the sky of the sun as seen from Earth.  That means the penumbra of shadows on Mars are just over half the size of the penumbra of shadows on Earth.  Much sharper!