My favorite things about these new findings and studies from Auckland, Japan, Chile, or probes like Kepler, are that they are all agreeing the number or Earth like planets is probably around this same amount, somewhere in the tens of billions. Knowing this information, there's no doubt in my mind we aren't the only intelligent life in this galaxy, and even cooler, there's some species out there that might have a billion years of intelligent society under it's belt. Look at what we've accomplished in the last 100 years, then think what we might have if we exist for a billion more... And this is only about our own galaxy, let a lone the billions of other galaxies in the universe. All throughout history people always thought we were special, but then people like Copernicus, Kepler, Galileo, Hubble, and now these new scientists shattered that centrism. Every step of the way people like them are proving that we are extremely NOT special. It's hard to believe that only 500 years ago the common agreement was that the Earth was the center of the universe...
I love your line of reasoning and agree with you that it is promising that all astronomers are converging on similar estimates. However, I take away something a little different from these findings. To me, it makes the quietness of the universe that much more strange. I think the fact that there are so many Earth-like planets makes it increasingly probable that there are no intelligent civilizations with even hundreds of thousands of years "under their belt" let alone millions or billions. We are only starting to grasp what an intelligent civilization with hundreds of thousands of years under their belt might look like. It seems to me very probable that if we don't kill ourselves our civilization will be quite loud in less than a thousand years. The fact that the rest of our galaxy is quite is telling (to me). I can't help but conclude either: a) we are the first
b) intelligent civilizations have a short life-span
c) or the space expansion hypothesis is incorrect (and transcension hypothesis is more likely)
Good points, and I agree with a/b/c being possibilities. To add a couple others... d) Other intelligent life already knows we're here and chooses to ignore us. e) Faster than light travel is impossible for even the most advanced species, so exploration and finding new species is too time consuming, not worthwhile, and unproductive, and contact between intelligent species is extremely limited or perhaps non-existent. The quietness of the universe is easily explainable (not saying it's populated and there's intelligent life everywhere, but even there was the quietness makes sense). We've only been broadcasting radio briefly, and we're already switching to digital and scrambling the vast majority of our signals. It's gonna be static if anyone listens to us. Also, if there are species that are spread across multiple star systems, they had to have found a faster communication method than radio, which means we aren't even listening or looking for the right types of signals. Perhaps the universe is extremely "noisy", but we're still examining and looking for signals that most species only use for a short time span in their development. It's arguable advanced life would be using some complex and robust multiband broadcasting that spreads across radio, uv, ir, and all visual bands... but we pretty much just look for specific frequencies because that's how WE would communicate right now. Hell, advanced species could be taking advantage of quantum entanglement to send communications. We wouldn't even begin to know how to tap into that yet. So for me, the quietness could make complete sense. But, space could also be so vast and difficult to travel that it's not worth it to meet or travel to other species. And that would be disappointing.
Definitely plausible for both d) and e). For some reason d) is a very creepy possibility. Certainly if a Type II, III, or IV civilization wanted to remain undetected they could achieve that goal. Some have even suggested that a civilization hundreds of thousands of years old would produce patterns that we might not be able to detect at all. For example, we still do not know what the universe is composed of (e.g., dark matter/energy) and have limited means to detect these natural phenomena. It could be a similar case for advanced civilizations. Possibility e) is just depressing to me. However, I don't believe it is very likely. Even if light is the universe's speed limit we already know of many theoretical ways to circumvent this limit. I would suspect that a Type I or II civilization would be able to figure out how to deal with the light travel issue. Either way, I'm excited for the James Web Space Telescope. We may be able to start to answer some of these questions with empirical evidence!
I'm just writing a blog post (it will be up soon ) on global population. Global population is declining (and declining quickly). A recent study concluded that human population should stabilize around 2050 between 8-9 billion individuals. Overpopulation is always what incredulous people say when futurists discuss the possibility of radical life extension. But those people don't realize that the largest demographic shift in human history is already underway and accelerating. Also, if the technology to extend life indefinitely exists... people won't turn it down. Think about the technologies that exist today that enable more people than ever in the history of our species to live into their 80s and 90s. Do any of them say "no it would be selfish to get this heart transplant... just let me die." Hardly anyone. If we develop technologies that allow people to remain healthy and live much longer... no one will turn it down. The result of these transitions will be a human species that have very few children (if any) and live much longer (150-200) and those are conservative estimates.
Wait, wait. Do you mean that the rate of increase of global population is declining? This is the other place you lose me. How do we correlate longer life with fewer children, automatically? Governments worldwide step in? Or the third world catches up to the first world in terms of birth rate? I wouldn't see this happening naturally for hundreds of years.The result of these transitions will be a human species that have very few children (if any) and live much longer (150-200) and those are conservative estimates.
The rate of increase in human population growth peaked in 1962 at 2.2%. It has been declining ever since (currently at 1.1%). All statistical models posit that 2050 will be when we plateau and the whole world will be at replacement level fertility. (Almost done the post detailing the reasons why this is happening). Also, longer life does not directly mean fewer children. However, what is leading to decreasing fertility is not going to go away (again post coming soon). Many people in our generation in developed countries will not have children. This will be the first time this has happened in human history. The more affluent, more urbanized, more educated people become... the fewer children they have. Government do not need to step in for this to happen. This is just how humans do. Of course, this is all contingent on the developing world continuing to develop at their current rates (which would see most people living at developed world standard of living by 2050). I suggest watching some of Hans Rosling's TED talks on future demographics. So I conclude personally that if we continue to decide to procreate way less - and we have technologies that will allow us to live much longer - then we will have a population with longer life and fewer children. Which will allow us to keep a stable population.