The Perpetual Present
If all moments in time exist equally, with past, present, and future all real from different positions, then the moment of your death already exists. So does the moment of your greatest joy. How should that change how you live?
The 'block universe' view of time, supported by Einstein's theory of relativity, holds that time is a dimension like space: all moments exist, and what we call 'now' is just our current position. This view eliminates the flow of time as a physical fact, with strange implications for free will, regret, and anticipation.
The physics behind it
In special relativity, the division of events into past, present, and future is observer-dependent. Two observers moving relative to each other will disagree about whether events are simultaneous. There's no universal "now."
The block universe interpretation takes this seriously: if "now" isn't a fundamental physical fact, then the past and future are as real as the present. They exist at their positions in four-dimensional spacetime; we experience them sequentially because of how we move through that space.
What the block universe implies
If all moments equally exist:
- The present moment of your happiest memory is just as real right now as this moment is. It hasn't "gone."
- Regret is strange: you're lamenting the existence of something that's still there.
- Anticipation is also strange: the thing you're waiting for already exists. You just haven't arrived at it yet.
- Free will requires reexamination: if the future already exists, in what sense are you "making" it?
The experiential puzzle
Even if the block universe is true, we only ever experience one moment at a time. The "flow" of time, the sense that the present is special and the future is open, is a feature of consciousness, not physics.
This creates a gap between how reality is and how it's experienced. You live in a universe where the past persists, but you can't go back. You move toward a future that's already there, but you can't see it.
The question it leaves
If you believed that all your past moments still exist, fully real, somewhere in spacetime, would you grieve lost things differently? Would you regret anything differently?