Update: I interviewed John Horgan about his views on the end of science (and other interesting questions). Read the full interview here.
I received an email from one of my readers yesterday. Her question was a simple one, but a very important one as well. In many portions in the updated (and original) edition of my book, I have claimed that our journey of discovering the fundamental laws of Nature is not over, it has only just started. However, there are some people like John Horgan, who believe that there are no new fundamental truths to be discovered. Maybe science is nearing its end. (I recommend Horgan's book The End Of Science or at least this article if you are interested in learning more.) These people do have a point. We are growing up in an age of rapid progress, but it doesn't make sense to say that this rapid progress will continue forever. We must eventually either find the answers to everything, or we will perhaps find that some questions will always remain unanswerable (as I have already said in the book, I think the latter is more likely to be the case). Now, at this point I’d like to make it clear that although there may be some deep questions we will never be able to answer, I don’t believe that we need to resort to believing in God to “explain” these questions. No, that is not what I think. Some things are unknowable, but that does not imply anything more. They are unknowable because of our limitations. They are not unknowable because there is some greater power (or God) behind them. According to science, it is entirely possible (and I would say very likely) that the universe exists just by itself, without any external help from God. My philosophy can be summed up in these words: Ordered complexity is a fortunate product of random processes. But let’s not go deep into this topic here, let’s keep if for another day.
Coming back to our question of whether science is going to end, of course, it does not seem likely that we will go on discovering profound new theories forever, there must be some final truth (which may or may not be accessible to us). I have already discussed the essence of this question in the book (see the chapter on the theory of everything). And it is true that we have discovered many important pieces of the jigsaw. We already know a lot. However, I still believe our journey is not going to end any time soon. Because in my opinion, there are still paradoxes that need to be resolved, problems that need to be solved and questions that need to be answered. Of course, I have claimed we will not be able to answer all questions, but I don't think we are reaching our limits yet. Today we understand a lot about the fundamental nature of reality, we just don't know for sure how to unify general relativity with quantum field theory, although we have some promising approaches like string theory. Then we don't know much about dark matter, dark energy, the Big Bang and the quantum measurement problem (and a few more things). But we do know almost everything else. We have a rough understanding of pretty much everything. So, doesn't it seem likely that science is nearing its end? No. And here's why: New questions will come up as we find answers to the above questions. Exploring these new questions will open up newer areas of research. And reality may be stranger than we can imagine. Okay, I admit it may be the case that after (and if) we discover a true theory of everything, there would be no profound and fundamental truth to be discovered, but still, working out the consequences and implications of what we have already discovered is going to take a lot of time, it's going to be a long journey, and along the way, we will refine our understanding of the world, and maybe even have some deep realizations about the fundamental nature of reality.
A good analogy is infinity. Most (mathematically illiterate) people believe that infinity is simply a huge, uncountable number… well, not exactly a number, just a notation, a concept… But if you ever decide to study real analysis and countability of sets, you’ll learn that even infinities can be classified into countable infinities and uncountable infinites. There’s a lot, lot more to infinity than you might think. Same story with science. Didn’t Albert Michelson once say that all there is to physics is to fill in the sixth decimal place? Then came quantum mechanics, and today we have theories of quantum gravity, they just give us a taste of our ignorance. Yes, we may be nearing the end of the journey, but we don’t have convincing evidence that this is the case. We should always be open to the possibility that there are many more new things to discover. In any case, nobody is stopping you from believing that science is nearing its end, and if you do believe this, you have a point. I find some of Horgan's arguments pretty convincing, to be honest. And I think there is a limit to our understanding, we will one day reach that limit and science will end then, but I just don't think we are near there yet. And the best way to find out whether we are reaching the limits of knowledge is to do real science and see how far we can go, instead of speculating about the end of science.