Australian astronomer ... massive governmental cover-ups ... bizarre electromagnetic phenomena ... a university library ... space aliens ... ham radio ... Fourier transforms ... science fiction ...
A few days ago they all came together. While waiting for my wife at a Tower Records store I find myself standing by the "Our Staff Recommends" magazine rack. I pick up a copy of a conspiracy-theory 'zine to browse. (Is anyone surprised at my choice of reading material?) In an article on communications from extraterrestrials, a name jumps out of the page and hits me in the eye: Ronald Bracewell.
Flashback: thirty years ago, in another coincidental encounter, Dr. Bracewell's delightful book The Fourier Transform and Its Applications chances to fall into my hands as I browse in the Caltech astronomy library. It's the perfect introduction to one of the sharpest saws in a scientist's mathematical toolbox: transform methods. Bracewell's book is full of pictures in addition to equations. The mission: develop instincts so that a person can intuit Fourier transforms instead of plodding through mazes of formulae and emerging with an answer sans understanding. (see JohnTukey (31 Jul 2000) for more on the technical topic of Fourier transforms)
Ron Bracewell is an Australian radio astronomer and electrical engineer, now a professor emeritus at Stanford, over the years honored many times for his scientific work. His textbook helps jump-start my learning about a wide variety of powerful transform approaches to problem-solving. (I am especially enamoured of the "Z-transform", though I still don't properly appreciate it — but obviously, with a name like that, eh?!)
So what is Bracewell doing in a rather wacky article about space alien attempts to communicate with earthlings? I can't answer in any detail, since I managed to refrain from buying the publication and only glanced through the article. But I went home with strong memories of nutty Analog sf magazine essays in the 1960's as well as more technically savvy but still fringe-science QST and 73 amateur radio magazine pieces.
In brief, since the days of Marconi there have been reports of "Long Delayed Echoes" (aka LDEs) — copies of signals that come back several seconds after transmission has ceased. A full speed-of-light trip around the Earth takes only about 1/7th of a second, so it's hard to see how an echo of significant strength could take more than a small multiple of that time to return. Moonbounce echoes are well-understood; they're also incredibly weak and barely detectable in the best of circumstances. Most probably the LDE phenomenon is a conjunction of hoax, misunderstanding, confusion, and wishful thinking.
But don't let that stop you from connecting the dots! Specifically, study the patterns of dots in star maps that, combined with maybe-mysterious LDEs and other observations, suggest to some that extraterrestrials from Epsilon Bootes have sent interstellar probes to our solar system. For inscrutable reasons the alien spacecraft don't send us any clear signals, although that would be utterly trivial for them to do. Instead, they intermittently echo back a few of our own radio waves, with delays that encode messages readable by Earthlings who are sufficiently enlightened. (The appositely-named Duncan Lunan was one such investigator.)
As with UFO observations, major governments deny everything, perhaps to preserve the mundanes from panic. John W. Campbell, editor of Analog, liked to publish articles about such ideas. As a skeptical teen-ager I enjoyed disbelieving.
And Professor Bracewell? Years ago, he wrote a brief speculative article on the topic. Given his academic credentials, his work became a prime reference to cite by the True Believers. So closes the loop ...