You Asked:
I’ve noticed that my machine seems more sluggish on rainy days. Is it possible that a drop in barometric pressure impacts the efficiency of microelectronics? Or is this all in my head? — Roxanne, Atlanta, Georgia

Marshall Answered:
Interesting question. There are several things that could cause a machine to feel “sluggish”. The four most obvious: 1) The processor is running slower, 2) The hard disk is retrieving data more slowly, 3) The Internet connection gets bogged down, 4) Some kind of background processing starts running in the rain. #1 seems unlikely, since the processor speed is controlled by a quartz crystal and won’t change unless you change something. #2 is maybe possible. This post shows that shouting at hard disks slows them down. Maybe rain causes extra vibration? On #3, maybe more people stay indoors in the rain, leading to more Internet use and therefore more congestion? And #4 might be caused by a virus that references weather.com and activates itself in rainy weather. That sounds far-fetched, but virus designers sometimes do strange things. Or what about a prankster who sabotages your machine on rainy days only? Again, it seems unlikely.

The other possibility is that it *is* in your head. People can have changing perceptions of time. “Time flies when you’re having fun” is a cliché, but it shows how our perceptions do change. Perhaps rainy weather changes your perceptions.

The way to find out is to do some testing. Example: try booting your machine on a sunny day and rainy day and measure the boot times with a stopwatch. See if there are weather-based changes. Try an Internet Speed Test in sunny and rainy weather. That would tell you about network congestion. Look at your machine’s average load in sunny and rainy weather. Maybe you open more windows in the rain, or use different programs? See if you can discover the answer. Who knows – there might be something to it.