How do you get 20 tons of gravel from street level to a side yard without carrying it up by hand? With a Stone Slinger! In the first video, yes, the man is driving the truck with a remote control.
On a whim I did this time lapse out our front window yesterday. I didn’t plan it out very well and I shot it through the half of the window with a screen, but it turned out ok, I think. Look for the tree branches springing upwards as they lose snow, car tire tracks evaporating, and the shadows and clouds moving as time progresses. The frames are separated by about 1 minute for the most part, but I was adjusting the interval in the beginning so not all frames are separated by the same amount of time. For the best effect, make sure the “HD” option is turned on (it should be blue and is toggled on/off by clicking on the letters) and the video is viewed in full screen. It’s 1m20s long.
A few days ago, on Saturday September 10, I attended the collegiate American football match between the University of California Golden Bears and the University of Colorado Buffaloes. Although we’ve lived in Boulder for over a year, and I work in the football stadium, this was the first Buffs game I have attended.
The game was an exciting one. The Bears led for most of the game, but the Buffs tied the game in the last minute of regulation, sending the game into overtime. Quite surprisingly, the Bears managed to win in overtime, something that as a True Blue, I am not used to seeing from my Bears.
This is the first season where the Buffs are a member of the Pac-12. I think they are not quite up to the standards of the Pac-12. Here are some of my observations from the game.
- The security getting into the game was a perfect example of security theater. They patted people down in a very cursory way searching for who-knows-what. Once inside the stadium, I didn’t see security officers in the stadium at all until the end of the game. In the closing moments they were positioned in front of the student section in a weak attempt to prevent the students from rushing the field. How are 20 people in yellow jackets going to stop 4,000 drunk undergraduates? In the end, because the Buffs lost, the students stayed put.
- Note to self: For the next game I attend, I’m putting all kinds of goodies in my office the day before the game. No one seemed to notice when I went inside to get my water bottle this time (to avoid paying $3.75 (!) at the concessions for water), so I figure I can store even more stuff.
- The stadium feels a bit dated, kind of like Memorial was before reconstruction. The isles are tight and the access gates are narrow. The loudspeakers are located at one end of the stadium, meaning that they have to be extra loud to reach the other end. The head referee’s microphone didn’t work, so we had to guess what penalties were or catch the hand signals (which was difficult because he faced the other way during announcements). However, the views of the front range and flatirons are supreme.
- I noticed several times during the game that the PA people are, frankly, rude. I always thought that music is required to be turned off during plays, but the PA people would let it continue into the beginning of plays. Also, at least once when the Cal Band started to play after a Cal score, the PA played music over them. It’s one thing to play over the 183rd playing of “Tribute to Troy” when playing U$C, but it’s unacceptable to play over the Cal Band.
The only cool thing about CU is the running of the buffalo, Ralphie. I think there should be the running of the bear. How about a 800-lb grizzly bear running across the pitch at Memorial Stadium?
Yesterday the Valmont Mountain Bike Park opened up to the public, and today I went over to check it out. The park has been discussed for many years, and developed over the last few, so it’s quite a moment for cyclists in Boulder. The park is oriented towards rider development of all ages. Each type of feature, such as cross-country or aerial areas, have options targeted towards riders of all ability levels. And even if you get yourself into something you can’t handle, there are bailout options to get around things.
The park is quite extensive and the designers have taken advantage of all the space they had available. Each trail feature is accessible by shared bike/walk trails, so parents can keep an eye on their kids even if they aren’t on a bike. Running down the middle of the park are two irrigation ditches (which is a crude description of them, they are much nicer than that) which splits the park into smaller sections. The smaller sections keeps things more intimate which is good in a park that will tend to get very busy. Nearly all of the single track trails are one way, which is very nice. Right now the vegetation is low so it actually isn’t a huge problem, but it is always very startling to come around a corner upon someone coming the other way.
To be honest, much of the park makes me feel like I have no skillz (yes, that’s skills with a ‘z’). Even the Skillz Loop, which is designed to be a place to learn skillz without being pressured by better riders to get out of the way challenges me. I tried most of the trails today, but not all of the technical options, especially stuff like this:
The park has two pump tracks, and I had fun riding one of them (Mesa Top) many times. The other one (Creekside) I did once, but it was very muddy and I didn’t want to ruin the pump track or get any dirtier than I was already.
I’m really excited about this new facility, and I hope to slowly improve my skillz over time at the park. It’s only a couple kilometers away from where we live, so it’s really convenient even if I only have an hour free. My only complaint right now about the park is it’s clear they haven’t quite figured out how to do the drainage from the sprinklers, because there are more than a few muddy spots around the park that contribute to trail destruction at an accelerated pace.
It’s show-and-tell time! Below are two movies I made using the volume rendering tools of yt. I’ve been using yt for a few years to analyze and visualize the cosmological simulations I make with Enzo, and only recently have I had time to begin to play with the new volume rendering stuff.
The first movie is a slow rotation around the entire volume of a simulation at a contemporary epoch, which means that this image is produced from the state of simulation at its end, 13 billion years after it started. The colors correspond to the density of matter in the volume, from dark blue to white as density increases. The simulation is a periodic cube with dimensions 20 Mpc/h on a side. In comparison, the diameter of our galaxy is somewhere around one thousand times smaller. This means that the whitest areas correspond to clusters of galaxies, and our galaxy would be just a small part of one of the white blobs. Be sure to watch the movie full screen!
Below shows the time evolution of the simulation from beginning to end. This is a thin slab of the center of the simulation (10% thickness) viewed from a corner of the cube. Notice that early on the matter is very clumpy everywhere, but rapidly forms dense knots connected by thin filaments. This is how the real universe looks! After about the half-way point of the movie you’ll notice that not much happens. Again, this is how the real universe looks! Much of the large-scale evolution of the universe was finished about 7 billion years ago. This movie uses comoving coordinates, that compensate for the expansion of the universe. If I were to use proper coordinates, which are the kind we use every day to measure normal things with rulers, the movie would show the simulation starting very small and then blowing up. Again, use the full screen option for the best image.
I found the faucet in my lab at school dripping this morning. I guess some air got in the pipes and a bubble formed. Each new drip was forming on the bottom of the bubble until it fell off. Fun accidental physics!