2023-06-09 52 0

Fri 9 Jun 2023 in 52,0: 52.2129778, 0.1220305 geohashing.info google osm bing/os kml crox

Location

Right next to the river on the edge of Jesus Green, in Cambridge

Participants

PeterRoder

Plans

This was a near-perfect oppertunity: a publicly accessible location in my city, only about a half hour walk away. The main drawback was that I had a 3 hour exam in the afternoon, couldn't guarantee availability in the evening, and probably should have been revising in the morning. Oh well, when the hash calls, you have to listen.

Expedition

I left home early, about 8:45, hoping the area around the hash wouldn't be too busy when I arrived. The journey to the hash was completely unremarkable, being a route I walk weekly.

The rest of the story is best told as images with captions rather than paragraphs.

Oh no. Do I have to walk through that?

Aha, there is a way round!

1m away is good enough.

The face of a geohasher who is thinking he probably should be doing something a bit more important

In the background of the photo of me, you can see Jesus lock. This lock divides the river into two distinct sections in Cambridge: Upstream, through the backs of the colleges is where you'll see punts. Downstream of the lock there are rowing boats instead. The lock is the furthest upstream narrowboats can get along the river during the summer; during winter they are allowed to journey up as far as the weir near Darwin college.

Some stats from the expedition

The return journey wasn't particularly interesting. I tried to use a slightly different route for variety, but I didn't want to waste too much time, so it was mostly the same route.

Achievements

Is it true that PeterRoder earned the Speedrun achievement? In principle, yes. But I did not have the foresight to time the expedition, particularly because the achievement didn't yet exist and I was in a rush. As such, the only method I have for determining the precise timing of the expedition is through the tracklog, which didn't start for the first ~6 minutes. The fairest approximation I can give for the time from leaving to re-entering my room is 1:00:06 (see calculations below), which would definitely give a sub-1 hour time from leaving to reentering the building. (2023-06-09 52 0).

The earliest trackpoint in the tracklog is at 7:52:34, 52.19619, 0.11413. I took a slightly different route on the return journey, but the time to the point at the same latitude should be about the same distance away. The outward journey was actually slightly quicker due to a door I could get out of but not in through, but I am not accounting for that here.

On the return journey, I was at latitude 52.19624 at 8:39:22, and 52.19608 at 8:39:36. Linearly interpolating gives latitude 52.19619 at 8:39:26.

The final few trackpoints were:

• 8:45:05 52.19408 0.11216
• 8:45:10 52.19416 0.11205 not yet reached my room
• 8:46:03 52.19410 0.11225 in my room
• 8:46:26 52.19410 0.11225
• 8:46:27 52.19411 0.11225

I'm taking 8:46:03 as the finish time for this calculation, but it could easily have been half a minute earlier. (Note also that changes to this value have a double effect on the calculated total duration.)

So the estimated time leaving my room is 7:52:34 - (8:46:03 - 8:39:26) = 7:52:34 - 0:06:37 = 7:45:57.

This gives a total estimated expedition time from my room to my room of 8:46:03 - 7:45:57 = 1:00:06.