How to eat a croissant

April 1st, 2018

Do you hear everyone talking about enjoying these flaky crustaceans, but are too embarrassed to try one because you don't know how to eat them? Don't worry, it's simple. Use this simple guide and you can walk with confidence into the nearest café.

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Seeing plants move

March 29th, 2018

You've probably seen cool time-lapse videos of plants growing. Probably also videos of sunflowers moving to track the sun. But do you have a sense of how fast they actually grow and move? It's surprisingly close to the limits of human perception.

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“Safety drivers” are a sham and a scapegoat: Uber and Desert Bus

March 23rd, 2018

This past weekend, one of Uber's autonomous vehicles struck and killed a pedestrian in Arizona, Elaine Herzberg. Video reveals that even as Elaine crossed in front of the car, the car did not stop or even slow. She was well within range of the vehicle's LIDAR, and local residents have posted their own videos showing that there was plenty of light to see by as well.

It's clear that Uber's reckless and callous company culture has produced an unsafe vehicle; in retrospect, it was always going to be Uber that took the first life. But what of the so-called "safety driver" sitting in the driver's seat? Dash video shows that she was looking down at the time of the accident (perhaps at a phone). Is she not to blame?

I submit that blaming the safety driver is both useless and dangerous.

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Oxalis leaf-opening time-lapse

March 23rd, 2018

I decided to take a time lapse video of my Oxalis plant's leaves unfurling in the morning. This was a good decision! Let's see if the video (30 MB) shows up properly here:

If you have a big monitor, I recommend full-screening. It's 1920x1080 pixels.

This is probably Oxalis triangularis; the seeds or roots happened to be present in the dirt I was using to pot up another plant. The leaves perform this unfurling every morning (I think triggered by both light and schedule) and then close back up after the lights are out. The flash of light you see in the beginning of the video is me turning on the lights and opening the curtains. There's a delay before the plant responds, and after all the leaves are open you can see some of the stalks jockeying around to get a sunnier spot. Plants are doing this sort of movement all the time. It's hard to notice because of the timescales.

I had meant to take a series of time lapse photos, but accidentally took a 2 hour 18 minute video. The following was supposed to speed up the video by 400x, but instead is about 160x. I don't really know how to adjust frame dropping in ffmpeg, so I just fiddled until I got something I liked:


# The video was in 2 GB chunks in the `raw/` subdirectory, so I first had to
# put the filenames in order, then make a "join-file" for concatenation:
ls -1 raw | sed 's/^/file raw\//' > join.txt
# The audio was pointless noise, so I stripped it out:
ffmpeg -f concat -i join.txt -c copy -an joined-quiet.mp4
# Time lapse, with incorrect output filename:
ffmpeg -r:v 4800/1 -i joined-quiet.mp4 -r:v 12/1 sped-up-400x.mp4

What I ended up with is a 30 MB H264 video, 1920x1080 (pretty big). I could have smashed it down farther (got it down to 10 MB in one trial with HEVC), but I don't know much about browser support for various video formats, so I left it alone. Much better than the 16 GB source video in any event!

Router anti-recommendation: Asus RT-AC68U

February 24th, 2018

I bought an Asus RT-AC68U this weekend and tried to set it up. I was excited at first -- some aspects of the router are refreshingly better than the competition -- but ultimately I found it unusable problematic.

Updated after discovering a combination of misconfiguration and ISP shenanigans. My apologies to Asus, although there are still some serious issues with this router.

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