More from Metzinger’s The Ego Tunnel:
A complete scientific description of the physical universe would not contain the information as to what time is “now.” …In real life, this is the job of the conscious brain: It constantly tells the organism harboring it what place is here and what time is now… Strictly speaking, no such thing as Now exists in the outside world.” (pp. 34,36)
How so? One of the benefits of a scientific description of the space-time continuum is that it enables an observer to locate specific points on that continuum. Metzinger is prepared to acknowledge the reality of a world outside of our internal representation of it, a world that includes objects occupying specific coordinates in space. Objects in the world also occupy time coordinates: they come into existence, endure, disintegrate. Processes and events in the world unfold over discrete intervals of time: they begin, they happen, they end. I understand that, for the scientist, identifying the specific coordinates on the space-time continuum is usually a third-person activity: things positioned on the continuum are there; they are then. For me, an individual subject occupying those coordinates, I am here, I am now. These are just two different vantage points for observing the same set of space-time coordinates — coordinates that exist in the real world. Like being at the eye of a tornado, the coordinates are no less real just because I happen to be in the middle of them.
Metzinger contends that the subjective experience of the Now is an “illusion.” It takes time for our sensory apparatus to transmit signals to the brain and for the brain to assemble these inputs into a coherent representation. Consequently what we experience as “now” is actually a re-creation of what was happening a fraction of a second ago. That’s true, but to call “the now” an illusion seems like a serious overstatement. It’s possible to describe with precision the causal processes linking my representation of the now with the real-world now; it’s possible to compute the time lag between the real external now and my internal now.
Metzinger reminds us that the color we perceive as apricot-pink doesn’t exist as such in the electromagnetic waves pinging against our retinas. Apricot-pink is the way humans represent that band in the light spectrum. What is the time continuum really like, or an interval, or an instant? Do we experience time as it is, directly? Or, as with vision, do we represent time in a way that’s dependent on objective time but that’s also transformed by our perceptual and cognitive systems? The latter is probably the case. But if our subjective experience of the color apricot-pink is more than mere illusion, so too is our experience of time.