How fast does the Sun move?

How fast does the Sun move? I don't mean though the galaxy, or the universe, but simply how fast does it move across the sky? I've seen it stated categorically that the Sun moves at 15 degrees per hour. But, for one thing, 15.000000° can't be perfectly correct at all times, because the Earth's orbit …

Contaminating space

In April, 2019, Israel's Beresheet spacecraft landed on crashed into the Moon. It later emerged that it was secretly carrying a supply of live tardigrades -- microscopic creatures known for their hardiness. Naturally, many observers, joking or not, brought up the idea of accidentally contaminating the Moon with destructive Earth life. I worry about a …

An un-unzippable ZIP file

Apparently, I'm writing a series of articles about ZIP format. Here's a curiosity. I'm going to use the Info-ZIP zip program to make a ZIP file that the Info-ZIP unzip program cannot unzip. I'll only do things that should be benign, i.e. things that a normal user might conceivably do. This article assumes you have …

Survey of ZIP APPNOTE documents

[2019-09-21: I've edited this document to include some new discoveries.] I already wrote an article about the version history of the PKZIP software, so now it's time for one about the version history of the ZIP format. That sounds like it should be easy, but… not so much. I think the format versions are more …

Survey of PKZIP versions for MS-DOS

I wanted to know exactly what versions of the old PKZIP compression software were publicly released for MS-DOS, and some basic characteristics about them, particularly what compression methods they used when compressing files. Sure, Wikipedia has a list, but it wasn't quite what I wanted, and it omitted at least one version I was pretty …

Will the real PKZ110.EXE please stand up?

I've been researching the version history of PKZIP, the once-popular compression software that gave us the still-popular ZIP file format. There are two important MS-DOS versions of it: v1.10, released in March 1990, which was the latest official version for more than 2.5 years, until v2.04c(?) was released in December 1992.v2.04g, released February 1993, which …

I could care less about your word crimes

I always assumed that pretty much everyone knew that the phrase "I could care less" doesn't make literal sense. I assumed it was simply an unfortunate shortened form of "I couldn't care less". I think it's popular because it has better cadence. It might be helped along by the likely element of sarcasm in it. …