Of the various metaphors used to point to Tao -- aka Pure Awareness, Dharmakaya, Buddha-Nature -- the metaphor of “space” is perhaps the most common. This makes sense, given our typical understanding and experience of “space” -- as something non-specific, all-encompassing, trans-personal, ever-present yet also rather elusive, intimate yet un-findable (impossible to “grasp”). Space -- as typically conceived -- is that within which all the “things” of the world (including our human bodies) appear, while seemingly maintaining its independence from them.
The notion of “space” might elicit images of vast blue Colorado skies, or of the “outer space” through which, for instance, the Starship Enterprise (for its glorious seven seasons!) intrepidly traveled, going where “no one has gone before.” Space is endlessly mysterious, endlessly vast .... very similar, it would seem, to Tao or Dharmakaya or Pure Awareness: the innermost essence (or so we’re told) of who we are.
In the world of physics, on the other hand, “space” is very much of a technical term -- pointing toward an endlessly-elusive “something” -- whose meaning is anything but straightforward, and has undergone numerous re-visions.
If we’re interested only in using “space” as a metaphor -- relying simply upon the way it’s typically understood and experienced -- then how physics formally views it may be entirely beside the point.
But if our spiritual path is a nondual one -- and so takes us into a territory of experiencing/understanding there to be only One Reality -- then presumably this “one reality” would not exclude so-called “physical space.” At which point it becomes quite legitimate to ask: Is physical space in some way equivalent to the space of Tao (Pure Awareness, Dharmakaya)? Under what circumstances can the former remain simply a metaphor for the latter, without simultaneously admitting its identity with it?
The answer would seem to have much to do with the three general stages of spiritual unfolding, described within Zen Buddhism via mountains/rivers images:
(1) mountains are mountains, and rivers are rivers;
(2) then mountains are not mountains, and rivers are not rivers;
(3) and, finally, (again but with an important difference) mountains are mountains, and rivers are rivers.
(Or, in the language of the Diamond Sutra: a is not-a, and therefore is truly-a.)
To tease this out, a little bit more -- exploring how space metaphors might function at different stages of our spiritual unfolding -- let’s take a broad-brush-stroke look at how physicists have viewed space, within the last several centuries.
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For 17th - 18th-century English physicist Isaac Newton, physical space was understood to be similar to a stage, upon which actors move. Like the actors in a play, moving about the stage, the various objects of our physical universe -- Newton proposed -- appear within a static, unmoving, constant three-dimensional space. In other words, space provides the stage upon which the action of our universe unfolds, without affecting that action, or being affected by it, in any way.
Newtonian Space & The “Witnessing” Function Of Awareness
When we’re still in ignorance -- still seeing “mountains as mountains, and rivers as rivers” -- we’re like actors within a play, who have forgotten that it’s just a play; or audience-members who are so engaged with the drama being enacted, that they temporarily forget that they’re in a theater. We’re fully identified with the character that we happen to be playing (or watching).
To begin to unwind this heavy identification, it’s skillful to cultivate the witnessing capacity of Awareness -- which might be likened to an actor becoming quite clear that they’re just playing the character; or positioning ourselves simply as an observer of the play -- say an indifferent or bored audience-member -- and from this position noticing the distinction between the actors and the stage itself. In other words, we learn how -- from our position as a “witness” -- to discern Pure Awareness from the objects that appear within it; i.e. Tao from the ten-thousand-things. Or, in the language of physics: we distinguish Newtonian space itself, from the objects appearing and actions unfolding within it.
Once we’re stable in this discernment, we’ve entered the “mountains are not mountains, and rivers are not rivers” phase of our spiritual unfolding. At this stage, what we’ve assumed to be true about our “self” and “world” is seen to be not entirely true; and we’ve glimpsed an aspect of ourselves which remains perpetually unaffected by the “action” of our lives.
For 20th-century German physicist Albert Einstein, space was not simply a three-dimensional “empty stage” (as Newton had previously envisioned it) but rather was part of a four-dimensional space-time fabric. Rather than being constant (as Newton had envisioned), space for Einstein was flexible: it adjusted (in inverse proportion to time) to allow for the speed of light to remain constant (at least in the Special Theory of Relatively).
This new understanding of space-time gave rise also to a new understanding of gravity. While for Newton gravity was conceived as a force which propagated through space (a kind of mysterious “action at a distance”), for Einstein is was a feature of space-time itself: an inherent characteristic reflective of the effect that curved space-time has on nearby objects. (An effect verified by the Gravity Probe B experiment.)
In this framework, matter and space are not wholly independent (as they were in Newton’s scheme). They are, rather, intimately interconnected: matter tells space-time how to curve; and curved space-time tells matter how to move.
Eisteinian Space-Time & The Space-As-Awareness Metaphor
In an Eisteinian idiom, space no longer works as a metaphor for an Awareness wholly unaffected by the objects appearing within it. (Light would perhaps be a better choice, for that which is unchanging and unaffected.)
It could, however, be used to point to ways in which Pure Awareness / Tao is not wholly separate from so-called “material objects” appearing within it. There is a relationship .... an insight which moves us in the direction of “mountains are (once again, but with a difference) mountains, and rivers are (once again, but with a difference) rivers.”