Disappearing Nablas, Disappearing Web Sites

by Brian Hayes

Published 9 January 2009

Earlier today Barry Cipra sent the following note as a comment to the post jsMath:

Website weirdness: The nabla symbol has suddenly disappeared from the equation on my browser (Safari, on a MacBook). It was there the last time I checked (a day or two ago), but now… gone!

With the generous help of Davide Cervone, author of jsMath, I’ve learned that the disappearing-nabla trick is not magic, and it doesn’t really have anything to do with jsMath. Barry is right that the character was present last week and that it was gone this morning. What happened in between is that bit-player.org (and my other web sites, industrial-landscape.com and grouptheoryinthebedroom.com) were transferred to new server hardware by the company that hosts my little Internet empire. It appears that several hundred files were left behind. Thanks, Bluehost.

Among the missing files, it seems, were some holding the PHP code that runs this blog. As a result, I couldn’t log in or even post an explanation of what had gone wrong. The only remedy was to restore a backup from before the migration. This has now been done, and I can confirm that the nabla is back. I need to check to see what other damage might remain. I’d be grateful for reports of any further weirdness: brian@bit-player.org

Tags for this article: computing.

Publication history

First publication: 9 January 2009

Converted to Eleventy framework: 22 April 2025

More to read...

Prime After Prime

The prime numers have been under the mathematical microscope for more than 2,000 years, and yet there’s a pattern in them no one noticed until just now.

The 39th Root of 92

Mathematics for electricians, piano tuners, and stargazers.

A Shy Woodland Creature

In remembrance of Martin Garner, 1914–2010.

Words for the Wordle-Weary

Can a computer program beat your score at Wordle? I don’t know, but it can beat mine.