I’m undertaking a 1000-day reinvention project, blogging here daily to track my progress. In Thursday Thinker, I share a smart idea or theory.
It feels natural to think of time as a line, and that we exist at each moment on a point on that line: the present. The near past and near future seem close to us.
Even if time is conceived of as a line, it could be a special kind of line: a dimension, a fourth dimension along with the three spatial dimensions of horizontal (width), vertical (height), and depth.
In the late 19th century, mathematician and sci fi author Charles Howard Hinton proposed that we may be 3D creatures living in a 4D space. We can’t detect the fourth dimension, just like if there were 2D creatures living in a 3D space (where the third dimension is threads running through the paper-like plane of the 2D space), they would only experience the third dimension as points in their 2D space. Similarly, he suggested, at each point in time, we detect only 3D cubes at one 3D location in four dimensional space. He coined a term for thinking about a four-dimensional structures: the tesseract, which you may have come across in Madeleine L’Engle’s A Wrinkle in Time.
Later, Einstein and his former professor Hermann Minkowski took Einstein’s 1905 Theory of Special Relativity (which was largely algebraic) and realized it could be understood as a geometric four-dimensional structure. Minowski 4D space (a.k.a. spacetime) is a mathematical framework that captures this.
In Blake Crouch’s novel Recursion, which Ray and I listened to on our recent road trip, memory provides a way to time travel. Crouch’s book suggests that though we feel like we exist only at one point, that’s because our perceptive systems squeeze nearby moments together to become that present. In reality, he seems to argue, all time exists but we just don’t have the ability to perceive it all at once, just like Hinton said. Instead, we perceive just.a small slice of all time at each moment.
These ideas relate to the block universe theory, which says that past, present, and future all coexist in a single four-dimensional spacetime structure. Some philosophers of mind argue that lived time (memory, anticipation, narrative self) is not reducible to spacetime geometry. The block is objective time while perception creates experienced time. In some quantum interpretations, the block contains all possible histories and consciousness or observation (perception) selects a path through them. This begins to sound like a five-dimensional space (height, width, depth, time, path).
Do these philosophies of spacetime have anything to say about how to live well?
Our limited perception of moments makes it hard to live simultaneously in the present and future, but that’s essentially what you must do to make good decisions in, for example, investing or personal reinvention, where actions and choices play out over many years if not decades.
In investing, for example, you might look at the current run-up in precious metals prices and think, “I should get into that.” If you were to take Ray Dalio’s advice and put 10% of your portfolio into gold as a strategic, long-term hedge against high debt, inflation, and currency devaluation and do that all at once, you might see an immediate loss, as gold could begin consolidating here. If you take only the short-term view, you might get upset and say “I’m not doing this!” selling out at a loss. But you need to keep the long view in mind.
In a career reinvention, as another example, you might decide to leave your technology career in order to focus on building a life as a professional artist or writer. But day by day you might see little to no success for years. How do you keep going when you don’t know what the outcome will be, and your success, if any, lies far in the future?
Does the block universe theory have anything to offer? I couldn’t think of something so I consulted ChatGPT.
ChatGPT offered this question for the block-universe investor:
If someone examined my entire investing life at once, would it look coherent—or merely reactive?
It suggested that because the block universe contains “completed curves” that if we take a perspective on our lives as representing completed curves in the process of being lived, we might be able to make better decisions.
In work life, Chat suggested that a career path that includes false starts, pivots, periods of drift, and late-blooming coherence can be made meaningful by considering them as part of the geometry. And it suggests, you don’t need to optimize the next step. You do need to be careful not to panick inside a local minimum.
I also consulted Gemini, which I’ve found to be more philosophically insightful than ChatGPT. The ideas were quite extensive, and I want to take more time with them before sharing.
But meanwhile I did think of one way that the block universe theory has helped me with both my investing and my career reinvention: making it easier to accept how things I regret turned out. If they were already laid out in geometric spacetime I don’t have to beat myself up for decisions I made.
You probably see that the block universe theory suggests free will doesn’t exist. I addressed this a bit in my article on the theory, but it’s not something I’ll get into here.