What I Wrote About In My All 2020 Mathematics A to Z was the feature of my mathematics blog today. Also this week, really, as I recuperate.
While you consider that, here's us getting close to our last ride on Vortex, and on Vortex's last (public) ride.

Vortex train returning. I would not have thought it hard to get someone else to ride front seat, although it does look like the kid in the second row maybe had too much roller coaster there.

Looking from the widow's walk back on the park; the queue still overflows the temporary barriers.

Train unloading and loading, as seen from above.

The memorial stones illuminated for the night as a train returns.

The station and crowd waiting for their last rides.

Clipboard counting ``Today's Fast Lane'' figures.

And oh, a view of the memorial stones seen under the queue's ladder.

We had our last ride, and our last night ride! Here's the train getting ready for more passengers.

Vortex's 33 years shield and a bell above it that I suppose used to signal when the ride was over and it was time to unload.

The next ride cycle loading up. I'm surprised I got away with sticking around long enough that they started doing safety checks.

Vortex's lift hill and one of the turnarounds, seen against a purple night sky.

Getting a look at Vortex after our last ride. Yes, once again it's me taking a picture of someone else taking a picture!
Trivia: The ``Deubner Shopping Bag'' --- designed by St Paul grocery store owner Walter H Deubner --- sold about a million bags per year by 1915. The bags are said to have been able to hold 75 pounds of groceries. Source: Small Things Considered: Why There Is No Perfect Design, Henry Petroski. Petroski notes, 75 pounds of groceries seems to be over-engineering the bag.
Currently Reading: The Age Of Revolution, 1789 - 1848: The Dual Revolution --- Industrial and Political --- in England and France, and its Global Consequences, E J Hobsbawm.