![]() bee
on Robinia pseudoacacia
Seven years ago
I wrote about seeing a jackrabbit stretch the way dogs do.
It happened again this week but this time I got pics.
This is this year's resident jackrabbit, the same one whose pic graced this page a week ago. The image changes with mouseover. ![]() ![]() ![]() roadrunner
this afternoon.
![]() The weather has turned
warm and a jackrabbit has settled on a shady spot near my house to lounge
during the daytime.
I wasn't seeing as many jacks as usual over the last
couple years and I'm happy that they're coming back.
Writing fiction doesn't come easily for me. I have a hard time
even getting started.
And yet every now and then I have a dream like a short story with colorful characters, foreshadowing, and something of a narrative arc.
How does a program organize a map to facilitate finding
the nearest restaurant or gas station or Uber car?
One way is to partition the earth's surface into grid cells,
which enables a graph search (check the cell you're in,
its neighbors, neighbors of neighbors, ...).
A flat surface lends itself to being partitioned into a
grid of square cells, but what about a sphere?
Uber wrote code to partition the globe into mostly hexagonal cells, where mostly means twelve pentagonal cells and all the rest hexagonal: like a soccer ball, but with a lot more hexagons. Such a grid has a roughly uniform cell-to-cell distance everywhere on Earth. The twelve pentagons are at the vertices of a regular icosahedron. Uber followed an example from R. B. Fuller that orients the icosahedron such that the twelve vertices lie in bodies of water. Uber has shared source code for their grid system on Github. It's hierarchical: it supports a range of coarse to fine grids. An overview is here and an interactive page showing their grids on a world map is here. Below: a screenshot showing my (rectangular) house and a hexagonal grid cell. ![]()
We didn't get much precip this winter and it's not
looking like we'll get a lot of flower action this spring.
A neighbor's Joshua tree is, nonetheless, getting its flower on.
Happy nineteenth, everyone. ![]() ![]() by Saharon Shelah.
One of several satirical floats in a parade
in Germany yesterday.
Many people commenting on
news
coverage thought such politically-themed displays
were out of place at a traditional yearly carnival.
We could use demonstrations like this in Washington though.
![]()
The bald eagle pair whose
live video stream
I've occasionally watched over the past few years have three eggs this year,
two of which have recently pipped (started to hatch).
From a web page summarizing recent goings-on at the nest: Pip1 confirmed 3/2 15:09. (We have no way of knowing which egg has pipped. They are laid without numbers.) |