Well the clouds are out in full force this week and it rains every now and then so nighttime astronomical observing is pretty much not going to happen. So, get out your meteorology study books or just stay inside or in this case I can refer to some comments received by readers regarding the detection of leakage radio emissions as part of the SETI program. In addition, it was time for the OC Science Fair and a new judge on the circuit, and finally remembering Stephen Hawking. First up
we received some feedback from Science Squad and Gravity Guy, Ken, who found, after reading my back of the envelope calculations, in the March 11 post, regarding alien detection of radio leakage signals from Earth, a published paper going into those details. Recall that in that post, my estimate that leakage from everyday radio and TV broadcast stations were expected to be detectable by alien civilizations if their radio telescopes had sufficient sensitivity and sufficient time for the radio leakage, now less than say 100 years old, had reached their receivers.
That paper described several additional factors that I had not specifically included in my calculations. First these authors note that it is more appropriate to use the total radio broadcast power, not just the power rating of one particular transmitter, and secondly, that the use of longer integration times, from hours to days, could be used to increase the receiver sensitivity. Nonetheless, the estimate range of reception was listed as about 100 pc, which is equivalent to about 326 light years. Ok, so the ball park estimate was right in this neighborhood too! By the way, if you like these sort of radio astronomy issues, you should check into attending the monthly OCA Astrophysics SIG, which is currently showing some radio astronomy lecture DVDs
If you want to follow up on this original reference paper, check out the freely available listing on the archive reference as shown in the figure caption. Thanks for that info, Ken!
|Additional info about detectable radio leakage from exoplanets wrt Earth (Source: https://arxiv.org/a|
This week has been the time for the Orange County Science and Engineering Fair at the OC Fairgrounds, March 12-14, 2018. Hundreds of middle school and high school students presented their science fair projects to the public.
|Inside, just a small section of the Orange County Science and Engineering Fair, March 12-14, 2018|
Big Oil Chemist, Dr. Arnold, who I worked with more than twenty years ago, and who we keep bumping into at various ongoing scientific meetings, had been urging me to sign up and volunteer as a judge at the science fair. Having sufficient judges who can review the students projects and provide feedback, and encouragement, is a key part of the whole science fair event. Well, I finally agreed to be a judge, after a couple of years of urging and nudging by Dr. Arnold. I just had a hard time, not because I didn't have the time or unable to make the time available, but because I couldn't see me as being a judge. It turns out that the whole scene though was really enjoyable and I really liked hearing the student's describe their projects and hear of their enthusiasm. I especially enjoyed meeting one young woman who had built a cloud chamber and had collected cosmic ray arrival statistics. Wow, this was really neat, especially because I had tried to build my own cloud chamber as a young high school student, and never quite got the thing to work. I just hope that I could offer the right amount of feedback, questioning, and encouragement to these young student scientists. Thank you, Arnold for your own volunteer work on the OCEF Board of Directors, and for continuing your encouragement for me and others to participate!
|Palmia Observatory Resident Astronomer shows up as one of OCSF volunteer judges (Source: Palmia Observatory)|
Finally, it is sad news to hear of Stephen Hawking passing at age 76. I (we) always welcomed his insight into the mysteries of the cosmos, especially his insight into black hole evaporation, Hawking Radiation, and how understanding black hole physics is very much all tied up with some deep connection to all of spacetime, gravitation and physics.
I have always enjoyed some of the Monte Python skits, in one classic example of which, Hawking is portrayed as running over fellow cosmologist, Brian Cox, with his wheelchair and then ascending into the heavens and soaring through the galaxy, all the time singing the Galaxy Song in his computer generated voice. This skit in some sense displays what I see as Hawking's final journey through the cosmos. RIP! If you haven't seen the Galaxy Song skits, which are quite funny, check out this one reference, of several versions of the main theme, at:
|Stephen Hawking, who helped us on our journey through the cosmos, continues on his own journey (Source: Monte Python)|