I voted yes with technology and civilisations. I have many reasons for believing so from logical ones to pure gut feeling.
But as you have included the Drake equation I’ll discuss that.
This is long post so feel free to skip by.
The Drake equation is merely a perspective. It is highly variable and evolves over time. It is a clever, simple and logical approach to putting a value down on paper. But it only gives you the number of civilisations that we are capable of detecting using current technology standards and the same for the detectees. It doesn’t measure those we can’t detect, and it doesn’t take into account inferior/superior science and technology. For example, those civilisations may not be emitting a signal strong enough to be detected or if they are, our detectors may not be sensitive enough. We also have a line of sight, which limits our ability to intercept signals and vice versa.
As for the last few factors, they are more dependent on our understanding than they are natural law. The discovery of commonplace exoplanetery systems is enough to shoot the number up drastically. The Goldilocks zone may be smaller/larger than we previously thought. That would influence the factors quite significantly. The concept of a Goldilocks zone might be entirely false and isn’t necessary. Not saying it is false however, just pointing out how something as simple as that can affect the results. The more we learn the more our understanding affects the outcome. And in 99% of cases it actually increases the probability of detecting life.
Another thing that limits us when we think of meeting civilisations is good old general relativity. Matter can’t travel faster than light. This is true. If a civilisation 500 ly wanted to visit us it would mean that it would take them >500 yrs to reach us. But what we are not accounting for is science and technology beyond our own. It is nearly impossible to predict with certainty what our own technological level will be in 1000+ years from now. Let alone what another civilisations capability is.
Just look at quantum physics here on Earth compared to classical mechanics to get an idea of some of the universes oddities. We have achieved and made things that were impossible only a relatively short time ago. There is absolute certainty that there is a lot more to be found out about the universe and possibly even the multiverse along with extra dimensions. This is some of the reasons why I do not rule out the possibility of intelligent life outside of the Earth.
Encap, unfortunately I have to disagree with you on the idea that probabilities don’t exist. If the universe was as black and white as you think, then we wouldn’t have much of the technology we take for granted today. I too used to think like that, and I totally understand why. The wave function is absolutely crucial in modern day science and all that is, is a probability. Quantum tunnelling is heavily dependent on it and if it had to exist as black and white, then it too wouldn’t exist. Also the multiverse theory is also highly dependent on probability.
