Latest Comic : Tuesday, March 9. 2021

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Appearance on tvN "You Quiz on the Block" episode #96

Commemorative photo with Yoo Jae-suk (left) and Jo Se-ho (right)

Thanks to an SBS show last year, I was invited to appear on the popular cable television program "You Quiz", and that episode aired yesterday. I liked the way it turned out, and it seems that a lot of people enjoyed it as well, especially the parts involving my wife.

Video

- Highlights (YouTube/tvN), #2, #3, #4
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- Highlights (tvN), #2, #3, #4
- Highlights (Naver), #2, #3

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Extreme temperature swing leads to EV range swings

705.5 km driven using 114.3 kWh at an average of -6C (21F)

There have been some wild changes in outside temperature during the past week. On Wednesday, February 17, it dropped to as low as about -10C (14F) and stayed consistently low. In contrast, it went up as high as 21C (70F) on Sunday, February 21. It just so happened that I needed to drive my Bolt EV from Naju to Seoul and back on those days. I did anticipate a big difference in drivable range between them, but it was still a bit jarring to experience it firsthand in such a short period.

The trips were made mostly on the same corridor of Honam / Cheonan-Nonsan / Gyeongbu expressways, which took up about 80% of the total distance and where I drove at a speed of 100 km/h (62 mph) on the dashboard. On other roads, the speed limits were always observed. I did not use any heating or air conditioning at all, as evidenced by the pie chart on the screen showing that all the energy was spent for driving.

A Naju-Seoul trip, which is roughly 320 km (200 miles) one way, can be made without a pit stop if the temperatures are above freezing. On Wednesday, I saw the drivable range drop considerably shortly after starting out. Although the battery was initially nearly full, I needed to stop and recharge mid-way, just enough so that I wouldn't be late for the schedule. The temperatures stayed between -8C and -5C (18F and 23F).

The return trip was the same - I filled up the car before starting, but had to recharge at the last service area to give myself a bit of safety margin. In the end 114.3 kWh was spent during the total trip distance of 705.5 km (438.4 miles), resulting in an efficiency of 6.17 km/kWh (3.84 mi/kWh). Given that I only try to spend a maximum of about 50 kWh on a single charge, you can see why I had to do the pit stops.
706.5 km driven using 85.1 kWh at an average of 17C (63F)

The situation on Sunday was completely different. It was exceptionally warm for Winter and I could foresee that I would reach Seoul quite comfortably on a single charge. Indeed, the temperature stayed around 20C (68F) for most of the trip until the Sun set. The dashboard showed about 100 km (62 miles) of range left when I reached the hotel.

The next day wasn't much different, although slightly cooler. I was returning to Naju with a full charge while the outside temperature was mostly in the 15C to 20C range (59F to 68F). Total distance of 706.5 km (439.0 miles) was covered using just 85.1 kWh, which gives an efficiency of 8.30 km/kWh (5.16 mi/kWh).

To put this into perspective, the efficiency was reduced by 25.7% just because the temperatures dropped by 23C (42F) and all other things remained more or less the same. Had I used heating, things would have been worse. This highlights how sensitive the electric vehicles are to outside conditions.
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Jupiter-Saturn Conjunction of 2020

Jupiter, Saturn, their major satellites, and star HIP 99314 are seen together on December 21, 2020 (click for full size)

Jupiter and Saturn appeared closest to each other in nearly 400 years on the Winter Solstice of 2020. For this Great Conjunction, the two planets were only about 6 arc seconds apart, which meant that I was easily able to take a photo of both in a single frame as you can see here. Some had expected that they might appear as a single dot, but it turned out that Saturn was discernible as a fainter "bump" on the top right side of Jupiter to the naked eyes.

To show the planets and the satellites together, I used varied exposures and then combined the results into a single photo. Titan was the dimmest that I could photograph, and it appears very faintly to the right of Saturn. Interestingly, a star named HIP 99314 was also caught in action between Io and Europa, which means that this conjunction was actually a triple affair.

Nikon P1000 taking photos of the conjunction

By the way, I was worried that I wouldn't be able to see the phenomenon in person because it was pretty cloudy throughout the day. Luckily, most of them went away as the Sun set and I was able to take the photos for about an hour until the low-hanging clouds started to block the view. The next closest conjunction happens 60 years later and I'm not sure if I'd be around to see that, so I was glad that the weather decided to cooperate in the last minute.

Device: Nikon P1000
Settings: 3000mm - f/8
- Jupiter: 24 photos, ISO 200, 1/30s
- Saturn: 13 photos, ISO 400, 1/30s
- Satellites: 17 photos, ISO 800, 1/5s
Filters: None
Time: 2020-12-21 18:20-18:40 KST
Location: Naju, Korea
Photos processed with PIPP 2.5.9, RegiStax 6.1.0.8 and Pixelmator Pro 2.0

Server upgraded to macOS Big Sur

iMac stuck on Setting Up Account step of the macOS Big Sur upgrade

I skipped upgrading the iMac serverโ€™s OS to macOS 10.15 Catalina last year mainly due to the removal of 32-bit application support. After a year, the clean-up of obsolete apps was complete, paving the way for the upgrade.

During the preparation, there was a bit of a hiccup with the MySQL database, But putting the data to a new one largely solved the issue and the website ended up loading much quicker. Two minor errors occurred after moving to the new database, which were quickly resolved by editing the configuration file:

1. "Query failed: Out of sort memory, consider increasing server sort buffer size"

Solution: increase sort_buffer_size from the default of 262144
sort_buffer_size=2097152

2. "Query failed: Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'blog.multilingual_body.value' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by"

Solution: remove only_full_group_by in sql_mode
sql_mode=STRICT_TRANS_TABLES, NO_ZERO_IN_DATE, NO_ZERO_DATE, ERROR_FOR_DIVISION_BY_ZERO, NO_ENGINE_SUBSTITUTION

With all the pieces ready I went with the installation of macOS 11.0 Big Sur. It took about an hour and except for a prolonged setup time of the iCloud, things went smoothly.

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Illuminated ISS crossing waning Moon

Brightly lit ISS passes in front of the Moon on November 11, 2020 (click for full resolution)

The International Space Station is usually in the Earth's shadow when it makes a pass in front of the Moon. But when the conditions are just right, you can see both illuminated by the Sun just like the photo I took above. When seen with the naked eyes, it looked as if a bright meteor was darting across the sky towards the Moon and eventually pass right through it. To witness this, I drove about 40km northeast to the edge of Damyang in the early morning.

Device: Nikon P1000
Settings: 3000mm - ISO 400 - 1/500s - f/8
Filters: None
Time: 2020-11-11 05:36:43 KST
Location: Damyang, Korea
6 photos processed with RegiStax 6.1.0.8 and Pixelmator Pro 1.8
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