by Aberdean Pimpinstein December 01, 2016
That portion of the ionosphere existing between approximately 160 and 400 km above the surface of the Earth, consisting of layers of increased free-electron density caused by the ionizing effect of solar radiation. Note 1: The F region reflects normal-incident frequencies at or below the critical frequency (approximately 10 MHz) and partially absorbs waves of higher frequency. Note 2: The F1 layer exists from about 160 to 250 km above the surface of the Earth and only during daylight hours. Though fairly regular in its characteristics, it is not observable everywhere or on all days. The principal reflecting layer during the summer for paths of 2,000 to 3,500 km is the F1 layer. The F1 layer has approximately 5 ´ 105 e/cm3 (free electrons per cubic centimeter) at noontime and minimum sunspot activity, and increases to roughly 2 ´ 106 e/cm3 during maximum sunspot activity. The density falls off to below 104 e/cm3 at night. Note 3: The F1 layer merges into the F2 layer at night. Note 4: The F2 layer exists from about 250 to 400 km above the surface of the Earth. The F2 layer is the principal reflecting layer for HF communications during both day and night. The horizon-limited distance for one-hop F2 propagation is usually around 4,000 km. The F2 layer has about 106 e/cm3. However, variations are usually large, irregular, and particularly pronounced during magnetic storms.
by IRISHrepublicanARMY January 03, 2004
All violins, violas, cellos and double basses have 2 holes either side of their bridge. These are, in fact, the instruments 'pair' of vaginas.
Dude, what are f holes?
F holes are it's pair of vaginas. That's how string instrumets mate. Endpin > either of the vaginas.
F holes are it's pair of vaginas. That's how string instrumets mate. Endpin > either of the vaginas.
by dstark March 15, 2010
No It doesn't mean fuck. Its a British food Show hosted by Chef Gordan Ramsay. The show revolves around different food themes and recipes. Segments include Women in the Kitchen, cook-offs with Ramsay, challenges, and Gordan's livestock that he ends up serving on the series finale.
Person 1: So do you watch 30 min meals
Person 2: Fuck that show I watch a real cooking show I watch the F Word
Person 2: Fuck that show I watch a real cooking show I watch the F Word
by Theblackness July 03, 2009
by Tony Tones November 16, 2004
by Bo Schimers June 02, 2006
Partially extended version of wtf. Carries same meaning and was created for use in the presence of those unfamiliar with wtf.
Person 1: Hey, Adam said he needs to borrow your TV again.
Person 2: What the F!? That's the the third time this month!
Person 2: What the F!? That's the the third time this month!
by K Wheezle May 26, 2004