Comments on: The search for ET continues — in West Virginia

By: SparkyFire

SparkyFire — Sat, 25 Jun 2011 22:00:13 +0000

time variation /mass/distance

By: SparkyFire

SparkyFire — Sat, 25 Jun 2011 21:56:51 +0000

freq changes w/resistance

By: SparkyFire

SparkyFire — Sat, 25 Jun 2011 21:53:24 +0000

every star has its own freq changes in freq modulation of planetary body will confirm

By: Amara D. Angelica

Amara D. Angelica — Sat, 21 May 2011 20:56:46 +0000

Agreed re fractal antennas. Paul Shuch (N6TX) of SETI League has designed some excellent ones. And right, freq. diversity might help penetrate the high noise level at non-waterhole frequencies. I’ve proposed ultra wideband as a logical ET strategy — if we knew the timing code (use Pi digits?). One idea that just occurred to me: create an autonomous bot that automatically learns to improve its data communication in noise, and use the timing codes it derives as search templates? Could do via SETI@home using fuzzy set-similarity joins (http://www.ics.uci.edu/~rares/pub/sigmod10-p495-vernica-long.pdf) via Hadoop (currently discussed on the AGI list re OpenCog)?

By: ks1u

ks1u — Sat, 21 May 2011 14:17:15 +0000

Amara, thanks for the comments. Yes, you are correct. In addition, there should be a solar cycle, which for an exoplanet may not be 11 years like here. The problem with antennas at these frequencies may be helped by fractal antennas. Unfortunately, until I retire and can implement some of these ideas, I can only share them for now. I thought about this in the early 80s and within the last few years have begun to discuss them more freely. There are certainly many glitches which would be encountered, but any method will likely have those. I also think it might be interesting to look for diversity transmitters within that wide band. Much like we get here for WWV. The military uses diversity reception with multiple receivers on different frequencies listening to the same transmission data. When one frequency fades the others may not. Of course finding the same signal on two or more frequencies simultaneously from an exoplanet would make for a very interesting occurrence.

By: Amara D. Angelica

Amara D. Angelica — Sat, 21 May 2011 12:28:58 +0000

KS1U: Interesting idea. I assume you mean by measuring differential day/night absorption or reflection of planetary (and ionospheric) RF in the HF region (or higher — think tropospheric ducting?) due to ionization layers (implying an atmosphere)? Supporting that, http://www.ias.ac.in/jarch/jaa/9/225-229.pdf reports solar RF flux measured down to 19 MHz. I’ve been talking to an amateur-radio researcher doing moon bounce at Arecibo — we just need to add an HF yagi and task Arecibo to monitor these targets. Or add a yagi on the GBT? Or should we send CQ? :) Problem is how to deal with HF attenuation from our own ionosphere (without going into space) — Amara (KF6TEJ)

By: ks1u

ks1u — Thu, 19 May 2011 00:31:55 +0000

I would like to see this search based upon a “radio signature” of the planet. This would take at least one orbit of the planet around the star and rather than look for a narrow band signal, a wide spectrum view would enable us to see the impact of an ionosphere on signals from the planet in question. I mentioned this to Dr. Shostak, and while he was polite though not enthusiastic, I still feel it has a higher probability of succeeding than searching for a +/- 1.4 gHz signal aimed at us. Surely any planet with technologically advanced life must have some type of ionosphere which varies from day to night and throughout the course of the stellar cycle.

By: Editor

Editor — Tue, 17 May 2011 03:53:27 +0000

Comment by SETI Institute’s Seth Shostak added.