From Bob Dylan’s Theme Time Radio Hour Yuletide Extravaganza Edition:
“Christmas was abbreviated to “Xmas” because X is not the Roman letter X, but the Greek letter “Chi”, it stands for the first letter of Christmas. The abbreviation became popular during the day when type was set by hand and when it was easier to put one letter to represent Christ.. no disrespect was intended.”
Merry Xmas, Patriot 🙏
A/C hi
A/C hr is t mas
When the AC is oscillating in the range of 3 kHz to 300 GHz it is referred to as radio frequency (RF). Thus, all RF is AC, but not all AC is RF. Ultimately, ions are controlled and measured in a mass spectrometer through the application of DC and AC, often in the RF range.
