accidental misspelling?

"accidentally accidently neither of them gets marked as misspelled for me. I feel like one of them must be wrong." But no! The Columbia Guide to Standard American English: accidentally, accidently.

frost

The "dew point" is the temperature where water vapor condenses into dew; it changes based on the amount of water in the air. When the dew point drops below the air temperature, you get dew.

When the dew point drops below freezing, it is called the "frost point"; when the air temperature drops below freezing and the dew/frost point drops below the air temperature, you get frost.

more about frost. I've been waiting for the first frost here but I don't think it has come yet.

rails

Robbie is saving a piece of railroad rail because "you can chunk it up into pieces about this long [2 ft] and it's useful for banging other pieces of metal on"--an improvised anvil. To cut up something like a rail, you would use an acetylene torch. (I had to ask, so I figured I'd write it down).

organic apples

apparently in apple farming one organic alternative to chemical pesticides is clay. I am guessing that would mean that they make a light slurry of clay and water and spray it on the apples.

css "image replacement"

image replacement by covering the text with the image (used today, for future reference).

launchd and cron

cron is deprecated under Mac OS X 10.4 and 10.5; it is replaced by launchd. You can schedule tasks with launchd by making a .plist, putting the plist in ~/Library/LaunchAgents/, and running something like launchd load ~/Library/LaunchAgents/my-task.plist. Cron is still present on the system, though. If you still want to use cron, just set up your crontab as usual with crontab -e and cron will automagically be turned on (launchd will load com.vix.cron, which tells it to check the crontab). a couple more details on launchd and cron, see also crontab.