The Question That Keeps Me Awake At Night

(calm music) - When I was 12, lying in bed, I had a sudden realization and was so scared that I desperately tried to suppress the thought. - The fundamental

question

is why is there something? Why is there something rather than nothing? How do we even begin to think about that? - You wake up at

night

to the sound of the wind blowing gently through your window. Dazed, you momentarily wonder what causes the air to move the curtains and make almost whispering sounds in the darkness. For the ancient Greeks, the wind was a mystery. As with many gaps in their knowledge, they attributed it to four gods known as Anemoi, whose behavior could range from benevolent to cruel.

However, as your senses return, you quickly reject such superstitious notions. Remember that wind is simply the movement of air caused by pressure differences within the atmosphere. As you rest your head on the pillow, you may wonder what causes those pressure differences to exist. Surely everything has a cause. You consider how differences in surface heating due to the sun will induce pressure differences and how those differences could arise due to surface topology, cloud cover and seasonal variations, but somehow this is not enough and now You move on, wondering what causes the sun. to heat the earth first and so on.

Your mind runs through a deeper and deeper series of causes and effects. Nuclear fusion, star formation, galaxy formation, until finally the Big Bang, and eventually perhaps you sit upright in a moment of panic and wonder: why does a universe exist? In fact, why is there anything? Welcome, dear friend, to the precipice of reason, the very limit of the knowable, sometimes called the fundamental

question

of metaphysics. It is this question that haunts me more than any other. It is the question that drives us. It's the question that brought you here. You know the question, as do I.

Sagan once wrote that science is a candle in the darkness. Before science, the world around us was often confusing, frightening and mysterious, with events occurring without rhyme or reason, but through centuries of effort, we have learned that everything we see around us around it has a rational explanation. For many of us, this is incredibly comforting. The universe has rules, order and predictability. Every physical effect has a corresponding cause, even if that course is currently unknown to us, a principle of universal causality, but this clarity of scientific reasoning can seem unstable, almost threatened, when we ask one of the simplest questions about the Big Bang. , the kind of question even a child could ask.

What caused it? The current answer to that question is that we don't know. We have ideas and speculations, but we don't have a really convincing explanation. It's a gap in our knowledge, but of course, that doesn't mean there isn't an explanation. It simply means that whatever the explanation is, it is currently beyond our reach, and there is nothing intrinsically wrong with that. It is perfectly fine in science for there to be unanswered questions, cosmic mysteries that often inspire the next generation of scientists. In fact, I often see this as one of the main strengths of science.

He doesn't pretend to know everything. He is not dogmatic in that sense. So maybe there is an explanation for this, whether it's an eternal cyclical universe, a multiverse of colliding brains, a simulation theory, or even theistic deities. However, in providing a causal explanation of the Big Bang through any candidate mechanism, we now, of course, have to explain that new mechanism. Why should there be a multiverse? Why should there be an eternal backdrop of cyclical universes? Now, if you are still with me and dare, I invite you to join me in taking one more step towards the abyss to which this line of questioning ultimately leads.

To start, let's assume that there is an explanation for the universe, the multiverse, existence itself, whatever you want to call it. Now, starting from this assumption, let's imagine that one day we reveal it. We discovered this proof, buried within our laws of physics, which beautifully explains the whole story. The universe had to exist, not because of some phenomena that preceded it, but because this law of physics demands it. The universe had no choice but to exist because of this law. It's a giant eureka moment. Champagne bottles are dragged out of a dusty back room and the physicists begin to laugh and celebrate their own genius when perhaps a lone voice in the background asks: "But why is that law of physics true?" While we might be tempted to ignore such a challenge, it is a legitimate question.

After all, physicists have spent centuries discovering causal explanations for many of our well-known laws of physics, and in the end, many of those supposed laws of physics ended up being merely derived rules that could be understood from deeper rules underlying them. to them. . As an example, Coulomb considered the electric force to be a distinct force in nature, but then Maxwell came along and showed that magnetism and electric force were actually just two sides of the same coin, electromagnetism. It was later shown that electromagnetism and the weak nuclear force are also, in fact, simply different aspects of the same fundamental force, the electroweak force.

And so there is hope, perhaps even an expectation that eventually all fundamental forces can be unified and understood by a single theory, perhaps even a single equation that describes the entire domain of physics, a theory of everything. So maybe one day we will discover this theory of everything, and when we understand it deeply, maybe it will become clear that the universe has to exist. That's why it's here. It is because of this fundamental theory, which could perhaps be an extremely simple formula, something like A equals B multiplied by the pinnacle of our intellect. So maybe now the champagne cart is finally coming out of the back room, those half-open bottles are open, and the physicists feel confident they've explained everything.

They have explained existence itself. But again, there's a lone voice, a protest in the back saying, "Hey, why does A equal B times X? Why doesn't A equal B plus X or A equal DBDX, or even anything else?" The fundamental problem is that this small equation, no matter how small we try to reduce it, still represents a finite amount of information. In a digital sense, there are a non-zero number of bits of data that appear to have been transcribed in some way in nature itself, but who or what was the author of that information? Of course, an obvious temptation here is to present a God, just as the ancient Greeks did, a God of the gap, but not just a gap in our knowledge, a gap even in our ability to understand the answer.

Of course, the problem with introducing God is that now one can rightly ask, "Well, where did that God come from?" And by posing that question, one can immediately see that we have barely answered the original question and, in fact, have possibly made things worse. But if we wish to approach this question boldly, we must, of course, ask ourselves the following question: Where did God come from? If we decide that this is an unanswered question, why not save a step and conclude that the origin of the universe is an unanswered question? Or if we say that God always existed, why not save a step and conclude that the universe always existed?

There is no need for a creation. It was always here. These are not easy questions. Cosmology brings us face to face with the deepest mysteries, with questions that were once addressed only in religion and myth. There are two separate but related problems we are discussing here. The first is how to deal with the fact that any chain of causal explanations must presumably have a starting point that lacks explanation. As a second ontological crisis it is nothing, it is simply much simpler and therefore more likely than something, and by nothing here I do not simply mean empty space.

I mean an absolute absence of space. No universe, no laws of physics, absolutely nothing. A concept totally incomprehensible to our primate brains. These are questions that physicists, theists, and philosophers have been debating for centuries. Robert Kuhn has a particularly excellent series of interviews on YouTube about these questions in his "Closer to Truth" series that I definitely recommend you check out. Instead of trying to summarize the many arguments put forward by many brilliant minds on this topic, I will use the remaining time to explain in my own words, in my own thinking, why we are so stuck on this issue and why.

Does it haunt me so deeply? So let's address point two first. Why is there something instead of nothing? The first idea we might come to is that nothing is somehow unstable and always necessarily generates something. That argument, however, is really motivated by the analogy of how empty space is unstable due to quantum fluctuations, which is certainly true, but there you already have two entities at play: space and quantum mechanics, and therein lies the problem. problem, because that's nothing. As difficult as it is to imagine, we are considering absolute nothingness, which means that there are no rules of any kind that we can employ to generate instability, and there is also a similar problem with arguments about symmetry or invariance.

So an instability argument really just doesn't work. Well, then how else can we answer why there is something instead of nothing? Subtly, the very formulation of that question presupposes that nothing is a priori a more favorable state for existence. This thought is somehow instilled in scientists through Occam's razor, which is usually paraphrased as: "All things being equal, the simplest explanation tends to be the correct one", but was originally closer to "The plurality It shouldn't be positive unnecessarily." Occam's razor is a heuristic that we find useful when weighing different hypotheses in a statistical framework, but physics has no formal requirement to align with this.

As Feynman once noted, “nature is not required to be simple or elegant.” People ask me: are you looking for the fundamental laws of physics? No I'm not. I'm just looking to know more about the world, and if it turns out that there is a simple, fundamental law that explains everything, so be it. It would be very nice to discover it. If it turns out to be like an onion with millions of layers and we are tired of looking at the layers, then that's it. But whatever the outcome, nature is there and she will come out as she is.

So, inspired by Feynman, perhaps instead of asking why there is something rather than nothing, perhaps we should ask why one should reasonably expect nothing. Flip Occam on his head. However, even here I cannot find any consolation, because whether existence is as simple as A equals B times X or as complicated as Feynman's onion, one still has to grudgingly admit that nature still contains a finite set of immutable governing laws, information that has somehow been inscribed in nature itself, but since when does that information originate? This brings us to the question of recursive causation. Why is there something rather than nothing?

Why is there anything at all? Perhaps, as many have argued, that question itself is meaningless. You can't legitimately ask, because whatever explanation you can offer them, they will always reasonably say, "Well, what caused that then?" Infinite regression. Perhaps we could try to invoke a sort of self-causality cycle, like a paradox, where the beginning of this causal argument spins to the end, but this rather abstract idea would still be stuck with a huge degree of inherent complexity, making us wonder why loop exists instead of no loop, nothing? In the face of this crisis, one could argue that the question can never be answered, not even in principle, because our something here really represents everything, the totality of existence, and therefore, by construction, there can never be something outside of that which possibly serves as a causal explanation.

It's a bit like asking what is north of the North Pole? The question doesn't make any sense. Going deeper into this thread of reasoning, one could then argue that for some things to exist with a causal explanation, there must necessarily be some things that exist without explanation, so-called non-contingent or necessary beings. Now, that something could be a multiverse, it could be a god, something that in turn begets our universe, but as Sagan said, why add that extra complexity when we can save such superfluity and simply postulate that the universe exists without explanation ? Sometimes called aBrute fact, this is perhaps the most awkward answer to the question in this video, because it actually refuses to answer the question at all.

It's as if the universe itself was telling us to stop working on the problem. I think this is a case where you should suppress your natural tendencies. One of your strengths is your ability to evaluate the dynamics of a situation. Now you're frustrated because not only can you not see the solution, you can't even define the problem. What we face is neither a person nor a place, at least not yet. You're saying I should sit back, shut up and wait. Well, I wouldn't have put it exactly like that. The idea of ​​admitting brute facts into scientific discourse is deeply unpleasant to our logical palette.

Sagan's candle in the dark implies that there are no unanswered questions. Every mystery, every phenomenon, every problem can be addressed by science, even if we do not yet know the answer. In many ways, the demons that haunt our world were slain by science, but here the chain of inquiry is unceremoniously interrupted. We are stopped in our tracks, as if by a cosmological demon drawing a line in the sand and saying, "This is where you should stop your intellectual pursuits. No more," and I just don't know if I can accept it. that. One of the reasons why brute facts make me so uncomfortable is the danger they represent to scientific research itself.

If we admit the brute facts as a viable scientific resolution, why stop at this question? Every time we encounter a new mystery, one might be tempted to simply play the brute fact card again. There is no point in investigating this. It's just another brutal fact. And then I'm stuck and I stay up at

night

struggling with this still. I just don't know if I can accept the idea of ​​a brute fact. No. The entire mantra of this channel, of my scientific career, has been to remain curious, and now we are forced to extinguish that curiosity and swallow this bitter and brutal pill?

And yet, as unsettling as it makes me feel, it may be inevitable. - Tony, there was no other way. (calm music) - The fact that we are converging on this conclusion reflects discussions in the broader field and has become a common position of many scholars. This position of brute fact is perhaps most famously attributed to Bertrand Russell, who once said on this subject: "I should say that the universe is just there and that's all." A possible ray of hope is to consider the following: there are some concepts that we can widely agree are uncaused, particularly numbers and, by extension, mathematics.

Whether there is a universe or not, the abstract concept of numbers is independent of that. Perhaps this can offer some way out. Max Tegmark has latched on to this idea in his mathematical universe hypothesis, proposing that the universe is not simply described by mathematics, but is itself a mathematical structure. Here we have a vast landscape of mathematical universes and we find ourselves within one suitable for life through anthropic reasoning. At the end of the day, why is there something instead of nothing? I'm certainly grateful it exists, because this universe is so much more interesting with all this beautiful mess around us.

I'm not sure I'm willing to accept Tegmark's idea that mathematics is so fundamental to the universe, nor the uncountable number of universes that the theory precipitates. However, his work gives me some hope that we can avoid the idea of ​​brute fact, that we can remain not only thoughtful but also curious. (quiet music)