RE: No ET! Ever?
February 19, 2017 at 3:29 pm
(This post was last modified: February 19, 2017 at 3:38 pm by Anomalocaris.)
(February 19, 2017 at 2:55 pm)Mr Greene Wrote:(February 18, 2017 at 11:50 pm)Jehanne Wrote: Your original claim was, "the stars are in pretty much the same positions as when they were observed by the Greeks / Ancient Chinese." (emphasis mine).
In any case, the proper motion of the Sun around the center of the Galaxy (at nearly 700 times the speed of sound), would be sufficient to cause a narrow band radio transmission to miss the Earth, not to mention the Earth's motion around the Sun (around 60 times the speed of sound).
The wobble on the Earth's axis is an irrelevance, and calculating deflection could be done by fighter pilots in combat so hardly an insurmountable problem.
In any case unless you were targeting a specific star for some unspecified reason a general area would suffice.
Fighter pilots have radar to give them range to target. We have nothing comparable to measure range to stars. In any case the range measurement error tolerance acceptable for fighter combat is much greater than that acceptable to making a narrow pulse signal intercept a star. This is because in aerial combat, the dimensions of the target aircraft and the dimensions of the bullets are both vastly greater relative to range to target than the dimension of the target star and the dimension of the pulse signal relative to range to the star.
Blanketing an area can solve that problem, but it also greatly reduce the strength of signal reaching each detector in the area, and this magnifies the probability that the signal would be overlooked.