----- Original Message ---- From: Steve Witham <sw@tiac.net> To: math-fun@mailman.xmission.com Sent: Wednesday, July 11, 2007 10:32:57 AM Subject: [math-fun] Stairway to Heaven? I wrote to the webmaster of the HIPAS site http://www.hipas.alaska.edu/hipasweb/hipas.htm and they have improved the description of their transmitters: The Heater system consists of 8 transmitters capable of conducting amplitude modulation of 100 Hz - 20 kHz and phase modulation of 0 -20 kHz. Each transmitter can transmit up to 150kW at 2.85 or 4.53 MHz on CW mode. The HAARP transmitter is also in the HF band (3 - 30mHz), so neither is anywhere close to 17 Hz! I think a 17 Hz transmitter and antenna need to be quite different from HF far-cousins. In fact I'm having a hard time imagining a 17 Hz directional antenna in Alaska since the wavelength is 18,000 kM. CO2 is only .04% of the atmosphere by volume. Maybe the laser can be tuned to heat CO2. And then, maybe a heated column of CO2 can be a major absorber of 17 Hz radio waves even with an omnidirectionnal transmitter? I only watch EE from the sidelines. --Steve _______________________________________________ The Navy once had Project ELF that transmitted at 76 Hz to deep submarines. Perhaps some of that equipment could be recycled for this new purpose. The 17 Hz is the cyclotron resonance frequency, qB/(2 pi m), for singly charged CO2 molecules in a field of 50 µT. However, as the molecules are pushed to higher altitude (which is a pretty dubious assumption), the field becomes smaller and the resonance frequency drops. It would be nice if someone who has confidence in this project would post some quantitative performance calculations. Gene ____________________________________________________________________________________ Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user panel and lay it on us. http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7