Living on Borrowed Time
Mathematics indicate that there should be millions of intelligent civilizations in our galaxy alone, as much as 5 billion years more advanced than us, colonizing the space around them, but where are their radio signals? The signals should be there, but we aren't receiving them. This has been so baffling that it is referred to as a paradox (the Fermi Paradox). There are several possible explanations for this, and they are all bad for us.
Looking at the history of Planet Earth (the only experience we have on the matter), whenever one exploring civilization has encountered another, it has always ended bad for the one less technologically advanced. We civilizations don't know how to play nice with one another. Considering this, it is likely that another civilization long ago experienced the same thing, having warred among themselves and with other early alien civilizations. Seeing no benefit in waiting until other civilizations advanced to the point of being a threat to them, they began a practice of wiping out developing worlds as soon as they discover them (i.e. receive their transmissions). They may conceivably study them first and even record their histories and anthropological records out of curiosity, but having nothing to gain from an inferior culture (scientifically, artistically, spiritually) that they haven't developed themselves over the aeons, they exterminate them. This may explain why there are no transmissions coming our way. Every time one is sent out, the preeminent civilization wipes them out, and only those wise enough to remain silent continue developing in a dark corner somewhere.
A Loud-Mouth Star System
Earth has been transmitting radio waves willy-nilly for two centuries, even transmitting introductions to whomever might receive them, including coordinates on how to find us (not that they wouldn't know how to track a signal). Currently, our signals have reached a circle around our system with a radius of 200 light years, and gaining an additional light year every year (obviously). The closest star to us is only 4 light years away, so 200 light years in every direction is covering some ground. We're pretty far out from the galactic center, where such an advanced race may have developed, which may buy us some time. It will still take another 118,000 years or so for the entire galaxy to know we're here, and by then potentially millions of advanced civilizations will be aware of us, but it won't take near that long for someone capable of faster than light travel to discover us and send a mission to destroy us. In fact, it could happen any time now. We may well have signed our own extermination order the day we invented radio and been living on borrowed time ever since. Aren't you glad you didn't miss Rush Limbaugh and Mannheim Steamroller broadcasts? Much of the continuous broadcasting has documented our pettiness and insanity.
A Quarantined World
Another possible scenario is that there are plenty of transmissions going back and forth out there, but we can't receive them and they can't receive ours because an advanced alien civilization has already discovered us and placed a dampening field or cloak around our solar system that blocks transmissions. (If you dismiss this as far fetched, you haven't really considered the possibilities. We've come a long way in a few hundred years, and can't yet begin to imagine what a few million would make us capable of.) This could be good news or bad, depending on the intentions of those beings. We could be quarantined for our own good or the good of others. We could be a zoo or a prison colony like Australia once was, the abandoned descendants of a human civilization that has already conquered the stars. In this case, we could have also signed our death warrant the day our deep space probes penetrated the shield. It also begs the question, "What are they keeping us alive for?" or if the quarantine has nothing to do with us, the more frightening question is "What are they keeping us in here with?" Our own solar system is still near completely unexplored, and capable of harboring anything from alien life to biological weapons to space mines or even a secret storage of weapons (why not hide it in an uninteresting system inhabited by mere primitive life?).
Suicide Squad
We've already developed the capability of annihilating ourselves and have previously been on the brink, proving that we are dominated by mad men here at home so bent on ruling that they are willing to destroy everything in the attempt. Some alien mission may yet arrive intent on our destruction only to find that we have already done the job ourselves. Another prominent hypothesis attached to the Fermi Paradox is that developing worlds tend to destroy themselves early on before colonizing the stars, another reason we aren't finding them today. This seems very likely to have happened repeatedly considering our own history, but unlikely to have happened universally, considering the sheer number of developing worlds in this galaxy. It seems even less likely to happen closer to the galactic center (as opposed to our less fashionable end of the galaxy) where worlds are more likely to discover each other and set aside their petty differences in the presence of potential outside threats (and possibly destroy each other instead). In all that possibility, it is likely that at least some similarly developing worlds in the galaxy's ancient past would form a truce, alliance or trade pact that would allow each other to coexist. Such pacts wouldn't stop the combined federation from agreeing to wipe out newcomers, however, so all the above scenarios can still apply if we succeed at not wiping ourselves out first. Our race's best hope for not committing suicide is the discovery of other galaxy exploring civilizations not bent on our immanent destruction and taking the logical next step of putting the trillions of dollars of resources and human effort that is currently spent on all our collective wars with each other into the technologies that will allow us to harness our solar system's power and colonize other worlds so as not to leave all our proverbial eggs in one basket.
One hopeful example of this is the star KIC 8462852, which has been periodically dimming for no known reason. We don't know why yet, but one possible explanation is that it could be orbited by a large manufactured solar array that is collecting huge amounts of energy for an advanced civilization. Such a civilization could likely have unlimited free energy for all its citizens, and therefore be capable of advancing technologically at an astounding pace. As of October 2015, SETI, the Search for Extra-Terrestrial Intelligence, has turned it's attention to this system looking for radio transmissions. If we find them, this could be just the shift we need from a global to a galactic consciousness (read more about this planet here: http://www.space.com/30855-alien-life-search-kepler-megastructure.html?li_source=LI&li_medium=more-from-space). We will have quite some catching up to do, unmired by this reward and subservience based system of control that we are currently held back by, which keeps us fighting among ourselves rather than catching up with our galactic neighbors. Fortunately, Stephen Hawking and investor Yuri Milner announced a $100 million SETI initiative called Breakthrough Listen, which will help SETI continue its mission. (Read more about this and the Fermi Paradox here: http://www.space.com/30043-seti-search-for-extraterrestrial-intelligence-infographic.html).
The Cat's Out of The Bag
It's a good bet the Empire knows we're here. Whether further development is racing toward our own destruction or racing to escape it, it's a little late to stop now because we can't call back the transmissions we've sent. Nor are we likely to convince everyone to stop developing technologically and revert back to primitive tribal cultures. At this point, we should work to shift on our own to a galactic mentality and move toward developing as fast as we can, both technologically and mentally. Remember, an alien race may be billions of years more advanced than us, leaving us little hope to defend ourselves. We may do well to conduct ourselves in such a way as to seem nonthreatening and hope to be spared. They may not care much, having annihilated many such civilizations in the past. If so, having off world colonies may give our species a chance to survive a devastating event. Developing faster than light travel may make this even more likely. One thing's for sure, we need to come together, appear sane and look to the future (for as long as we have one).
Also read Stephen Hawkings comments on life in the universe I came across after publishing this article: http://www.hawking.org.uk/life-in-the-universe.html
