Reverse-Telescope Solar Statite

{WARNING: The next three paragraphs are buildup to the actual idea, for those unfamiliar with the subject. If you understand the Fermi Paradox, skip past the next three paragraphs.}

The Drake Equation (sound in principle, although any numbers you try to plug into it are suspect.) states that there should be loads of extraterrestrial life. After all, we live in a galaxy with an enormous number of stars, many of which (based on known statistics, which are admittedly sketchy) have planets. And some fraction of these planets ought to be able to support life. Judging by how quick life sprung up on Earth, it seems reasonable to assume that many of these life-supporting planets support life of some kind. (as well as can be judged from a sample size of one) Even after all this, there should be a massive amount of life in are galaxy. At the very least, one would expect more than one intelligent lifeform out there (although I admit that, with a sample size of one, nobody's really in a position to expect anything.)

So, why haven't we noticed a single sign of it? Not even a single wayward transmission has been detected to date. We would expect the Galaxy to be teeming with life, and yet we have never seen a sign of it. This is known as the Fermi Paradox. Although one could argue that we haven't been looking long enough (which we haven't), that we're looking at too small a band for transmissions (which we are), and any number of reasonable arguments, these can be solved only by time, technological advance, and whether society decides to care about this apparent pipe dream. However, one other solution to the Fermi Paradox is this- that everybody's listening , but nobody is talking.

It takes deliberate effort to send intelligible signals to the stars. Relying on stray transmissions from our radios and cellphones won't work- even our most powerful transmitters are pointed at other people, not the sky, and the spread of compression algorithms makes the sound of Earth almost indistinguishable from radio noise. Besides, technologies that leak away signals to the void tend to be outmoded and replaced, because (unless that's what they're meant to do) it's just a waste of power. Judging by our society, even under the best conditions, the window when civilizations are visible without deliberately making themselves so is small indeed.

Therefore, if we want to contact other civilizations, somebody has to be talking for the other to hear. Since they don't seem to be screaming out into the void, we might as well do it.

As such, I propose to build a solar statite. A statite is a device that uses a large solar sail and photon pressure to balance out gravity, in this case, the gravity of the Sun- they've been proposed, and we could actually (if we wanted to) build one without invoking any technology we don't have already or conceivably develop in a few decades. There's nothing actually new about them, we just don't have the architecture in place to build them.

This statite will be placed in a slow orbit out of the plane of planetary orbit, so as not to block the signal. Supported by the statite will be what essentially amounts to a Hubble-or-larger scale telescope, pointed so that the "eyepiece" is toward the stars. The telescope will also have a vane array, similar to Venetian blinds, on Sun end of this "reverse telescope." The basic effect of this is that, while open, this would make our star much, much brighter than normal to all observers in the beam, which itself will remain visible over a much larger range than the Sun itself would be. The vanes would be used to shut the beam on and off in some clearly intelligent pattern that couldn't be mistaken for a pulsar or something. Pi and the Fibbonaci sequence just sound like nonsense if you come in in the middle of the transmission, so probably we'd transmit something like one pulse, wait, two pulses, wait, three pulses, and repeat.

We’d probably also want to put some method of propulsion on the statite, in case we want to move it so that it points at some star system we preferentially want to signal at, like a star with Earthlike planets. In this case, we would tilt the solar sail, and photon pressure would cause it to go kiting off to a new orbit.

One advantage of this method of signaling is that it’s very simple and low-power. The enormous nuclear inferno of the Sun provides all the energy we need, all we’re doing is focusing it with a few mirrors. It has few moving parts, being largely reflective foil and optics, with the only electrical parts being a few solar panels to power the vane array and a simple, programmable circuit that modifies the sequence. It’s also low-maintenance, as we can pretty much stick it out there and forget about it. And it also gives us a target, because we can focus on preferentially scanning the skies for transmissions from stars in the path of the signal.

The only major disadvantage of this is that we’re essentially screaming our location at God-knows-who, or –how-hostile.