Julian Barbour, Albert Einstein, and Parmenides vs. Anaximander and Lee Smolin. Theoretical physicist, Julian Barbour, believes that what we experience as time passing actually consists of frozen moments of space-time in relation to one another (akin to a flip book). It feels as if time is passing, but like cinema film, past, present, and future, to borrow a phrase from Jacques Derrida, “always already” exist.
Albert Einstein once wrote that “People like us, who believe in physics, know that the distinction between past, present, and future is only a stubborn, persistent illusion,” and the pre-Socratic philosopher, Parmenides, also believed time to be an illusion, a conclusion he derived from logic. Being can’t pass into the state of nothing on its way to becoming something else, for nothing can come of nothing. Therefore, becoming must not occur. Parmenides’ student, Zeno, defended his teacher’s position with a famous argument: one can imagine slicing space infinitely fine, and so any object, to go from point A to point B, would have to pass through an infinite series. This can’t happen, so movement in time must be some sort of illusion. Everything is at rest; nothing really moves; all moments are eternal. Past, present, and future are right now. Think block universe.
Poetic, perhaps, and even a bit creepy–but is it true?
A different pre-Socratic philosopher, Anaximander, thought not. In his On Nature, quoted at the beginning of Lee Smolin’s book, Time Reborn (Houghton Mifflin Harcourt 2013), he wrote, “All things originate from one another, and vanish into one another according to necessity […] in conformity with the order of time.”
The world, in other words, is on fire, baby. Time is not an emperor with no clothes, but akin to the burning bush in Exodus: a god wearing flames.
Theoretical physicist Lee Smolin agrees with Anaximander, and the idea of time as fire is poetic, if a bit nervy–but who’s right?
Can science call this one decisively?
Smolin has long thought yes; that the data from NASA’s Fermi Gamma-Ray Space Telescope would provide a smoking gun in favor of the idea that time is really real, not just an emergent property out of more fundamental principles. How so? By showing the speed of light is not constant when measured over vast distances (ten billion light years), and therefore that time isn’t really relative to the motion of the observer. In other words, by proving Einstein’s theory of relativity wrong.
Put another way, Einstein says gravity slows time, not light. Smolin says if we can set photons to racing over sufficiently vast distances, and measure them, we’d find that, in fact, gravity slows light, not time. Time is constant, not light.
Lee Smolin’s Prediction. For Smolin, time is special. It is universal, not local. It might appear locally to us to be relative, but across the cosmos, and at the quantum level, time is not ultimately dependent on the speed observers are moving. It is not an emergent property of space, the laws of physics, and matter-in-motion, but fundamental. Instead, it is space, the laws of physics, and matter-in-motion that derive from time; it is they that are the emergent properties. Indeed, time is the only thing that is fundamental. Not God, not dumb luck, not the infinite multiverse. The buck stops for Smolin with time.
So Smolin has long believed that Einstein’s theory, in the final analysis, is wrong about the speed of light being constant, and therefore about the relativity of time in relation to an observer’s motion. There is a substrate to reality in which everything that exists, exists now, and is passing out of this burning moment into another moment at the same instant.
Here’s Smolin, writing all the way back in 2003 (which may no longer exist, if Smolin is correct):
Some of the effects predicted by the theory [of quantum loop gravity, a theory Smolin promoted at the time] appear to be in conflict with one of the principles of Einstein’s special theory of relativity, the theory that says that the speed of light is a universal constant. […] [T]he theory [of quantum loop gravity] predicts that the speed of light has a small dependence on energy. Photons of higher energy travel slightly slower than low-energy photons. The effect is very small, but it amplifies over time.
In other words, if Einstein is right, low-energy and high-energy photons, from a great distance (again, ten billion light years), will basically reach NASA’s Fermi Gamma-Ray Space Telescope at the same time. If they don’t; if the low-energy photons lag a bit, then the speed of light isn’t constant and time isn’t relative, but fundamental. Here’s Smolin again:
Two photons produced by a gamma-ray burst 10 billion years ago, one redder and one bluer, should arrive on Earth at slightly different times. The time delay predicted by the theory is large enough to be detectable by a new gamma-ray observatory called GLAST (for Gamma-ray Large Area Space Telescope), which is scheduled for launch into orbit in 2006. We very much look forward to the announcement of the results, as they will be testing a prediction of a quantum theory of gravity.
When Smolin wrote this back in 2003, he speculated on the consequences of any detection of laggard photons by the space telescope:
A very exciting question we are now wrestling with is, How drastically shall we be forced to modify Einstein’s special theory of relativity if the predicted effect is observed? The most severe possibility is that the principle of relativity simply fails. The principle of relativity basically means that velocity is relative and there is no absolute meaning to being at rest. To contradict this would mean that after all there is a preferred notion of rest in the universe. This, in turn, would mean that velocity and speed are absolute quantities. It would reverse 400 years of physics and take us back before Galileo enunciated the principle that velocity is relative. While the principle may have been approximately true, we have been confronting the frightening possibility that the principle fails when quantum gravity effects are taken into account.
Drum roll, please. Well, it’s 2015, twelve years later, and the results have recently come in from the space telescope, and been digested by researchers. This is via Phys.org (March 16, 2015):
One hundred years after Albert Einstein formulated the general theory of relativity, an international team has proposed another experimental proof. In a paper published today in Nature Physics, researchers from the Hebrew University of Jerusalem, the Open University of Israel, Sapienza University of Rome, and University of Montpellier in France, describe a proof for one of the theory’s basic assumptions: the idea that all light particles, or photons, propagate at exactly the same speed.
The researchers analyzed data, obtained by NASA’s Fermi Gamma-ray Space Telescope, of the arrival times of photons from a distant gamma-ray burst. The data showed that photons traveling for billions of years from the distant burst toward Earth all arrived within a fraction of a second of each other.
This finding indicates that the photons all moved at the same speed, even though different photons had different energies. This is one of the best measurements ever of the independence of the speed of light from the energy of the light particles.
In other words, this is Parmenides’ revenge–and Julian Barbour’s–and Einstein’s. Disturbing as the implications may be, the idea that we live in a block universe is alive and well. Time and change may indeed be stubbornly persistent illusions. Gravity really does appear to slow time, not light. It does not look like time is fundamental.
This means that when 20th century mathematician Hermann Weyl wrote the following, he may not have been far off the mark:
The objective world simply is, it does not happen. Only to the gaze of my consciousness, crawling upward along the world line of my body, does a section of the world come to life as a fleeting image in space which continuously changes in time.
Put another way, the speed of one’s gaze (whether “crawling” or zipping) from a particular vantage in relation to another thing, generates the illusion of becoming. All moments already exist alongside one another as a dimension in space-time. I’m curious to read what Lee Smolin makes of the latest space telescope data, but I can’t seem to locate anything by him about this online. I look forward to that.
A brief, speculative addendum on aspect seeing, Escher, and time. Weyl’s description of awareness “crawling upward along the world line of my body,” with “a section of the world” coming momentarily into awareness “as a fleeting image in space” seems curiously akin to aspect seeing (as with the goblet vs. two faces image in all introductory psychology textbooks; the figure-ground image).
The figure and ground in such an image is static and completely interdependent–you can’t have one without the other–but awareness ping-pongs back and forth between the two images as if trapped in a very simple space-time square of indecisiveness. Is it a goblet? Is it a face? Is it both? Is it neither?
What one affirms in one moment seems negated in the next.
Perhaps the cosmos combined with awareness is like this, but rather than a two-dimensional square, it’s a three or more dimensional box or bubble–a very, very large box or bubble. And because the box or bubble is vast, awareness never hits a wall to ping-pong off of, so it tumbles all in one direction (hence the illusion of time).
Think of an Escher drawing, Sky and water I (1938). The school of fish and flock of birds in the drawing are a mutually interdependent arising (to use a Buddhist phrase), and, akin to Schrodinger’s Cat, they are both there and not there depending on where attention takes hold. The fish and birds are not the same as what they emerge out of (both your brain and the drawing)–and yet, in a sense, they are. They’re not the self-same, but they’re inseparable from the viewer and each other–and are along a continuum. Whatever you affirm about either the fish or birds becomes a negation when pressed, for both are empty of an independent essence. Now there are fish, now birds–but the first now is just the flip side of the second now, and it has no independent or substantial essence. Now there’s a ghost fish. Now a ghost bird. And these are inseparable from awareness “crawling” (Weyl’s word) down the “world line” of what is.
Does this match, not just Einstein’s claim that time is “a stubborn, persistent illusion,” but the intuitions of a non-dual Buddhist like Nagarjuna or a poet like Blake? Is awareness the empty and moving image of eternity?
There is a story from the Zen tradition that goes like this: two monks view a flag blowing in the wind, raising the question of what moves. The first monk says the wind moves; the second, the flag. Their master passes, smiles, and says, “Mind moves.”