Absolute, true, and mathematical time, from its own nature, passes equably without relation to anything external.
Absolute, true, and mathematical space remains similar and immovable without relation to anything external.
Isaac Newton – Philosophae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), 1687
What a quaint notion. One which we says space and time exist independent of observation. To this day we continue to educate future generations on the classical theory of physics, one in which we are taught time flows like a river. Aphorisms like “Time and Tide wait for no man” fill our popular wisdom insisting that we are forever in a race with a clock that’s ticking away with no regard for us.
While Newton may have written these words, this understanding seems to fit naturally with our everyday experience. After all, we wake up each morning to see that time continues to advance and before long it’s night and another day passes us by never to come again. We leave with memories, journal entries, and receipts but no way to return.
In this chapter, we’ll investigate these notions and come to see that our assumption about time is flawed.
As Newton was taking on and solving the world’s quandaries one of his contemporaries, Leibniz, over in Hanover wasn’t always on board. Four years younger than Newton, and a prolific inventor in his own stead, he was the brains behind the Leibniz wheel – which was a key component of the first mass-produced calculator. Newton and Leibniz had an intense rivalry (both had independently derived Calculus) – one that even crossed into personal attacks as Leibniz called Newton’s circle the lost children.
Leibniz had a different view on space and time.
Space is the order of coexisting things. Time is the succession of coexisting things.
Leibniz
In his view space was what kept things apart and time is what organized events so they didn’t happen at the same time. Over two centuries later someone would express the same sentiment again. And he had a theory that would put time in its place.
The only reason for time is so not everything takes place all together at the same time
Einstein
Time as a flowing river
Our primary conception of time is like a flowing river. One that continues on with no regard for our participation. There is a Heraclitus quote that says you can’t step in the same river twice. (is this relevant?)
(quotes and examples of how we look at time like this)
Relativity: A wrench in the works
This view may have continued unimpeded in the world of physics, if it weren’t the trouble-maker Einstein.
Special relativity eliminates the concept of absolute simultaneity – the idea that there is a now everywhere right now. Relativity showed that that idea doesn’t even make sense. This doesn’t gel with our experience. If we were to call our cousin on the other coast she’s likely to answer the phone now. In our chat we’d talk about things we did right before the call and it would line up against our own timeline.
But when we dig further, the world looks a little more strange. Turns out that with really good clocks we measure that we have different time based on where we are. Time for example moves at a different tempo at lower and higher altitudes. Conceptually our heads age slower than our feet.
The flow of time is also impacted by our motion. So if our cousin was on Jupiter and moving then it’s even possible for her ‘now’ to be in our future. How could this be?
All of time all together
The theory underlying this is known as the block theory of the universe. The block theory conceptualizes all of space-time laid out all together. Brian Greene uses the analogy of a loaf of bread to explain this concept. At any given point we are in one slice of this space time loaf. If we were to slice that now it wouldn’t be a slice going across the the bread uniformly. It has to take into account our motion. Which means it’s possible to slice a now which results in a time years ago in Jupiter or years in the future on Earth (one possibly in which our cousin is older or younger than us).
To get our head around this we have to start by asking what is time really?
Time is what clocks measure
This definition seems circular and suspicious. But in order to understand it we have to put aside our notion of time as flowing. A better analogy is that of a movie reel. Each now moment in our experience is one frame of the film and it’s complete.
Each frame is complete in itself and contains all of the information. Our mind tends to fill in what’s next. In the picture above it has an expectation that the ball in flight will connect with the bat – perhaps we’ll hear the loud crack of the contact or the swoosh that is the result of a miss hit.
Time then according to this conception is the experience of one frame changing into another. That is, time is an emergent property of change. On a still day sticking your hand out the moon roof of a moving car makes you feel like it’s breezy but it’s the motion that makes it feel that way.
Laws without time
Most of the theories (since the time of Newton) that explain our physical world and its effects are independent of time. The only place where time shows up is in the law of Entropy which seems to indicate the time has an arrow. That we always go from high entropy to low entropy (why is this true?)
From the perspective of sentient beings, the answer seems obvious. As I type these words, I clearly feel time flowing. With every keystroke, each now gives way to the next. As you read these words, you no doubt feel time flowing, too, as your eyes scan from word to word across the page. Yet, as hard as physicists have tried, no one has found any convincing evidence within the laws of physics that supports this intuitive sense that time flows. In fact, a reframing of some of Einstein’s insights from special relativity provides evidence that time does not flow.
Brian Greene
What about our experience of time?
The key thing to remember is that our perceptions exist to help us make sense of the external world as seen from our view point. Much like how our brain stubbornly sees a 3-D shape in a 2-D diagram, it completes the picture by giving us a psychological experience of time passing by us. This is a helpful adaptation and interpretation because regardless of what is actually true it’s more helpful to think of time passing.
Take music for eg: music only works because our psychological perception. From a purely in the moment perspective all we hear is a note at a time. It’s the memory of the past note and the expectation of a future note that makes music fun. If the note that arrives is out of sync with our expectation it comes across as noise. The best music pushes the edges of expectation but not too past it.
Buddhism and Time
If the present and the future
Depend on the past,
Then the present and the future
Would have existed in the past.If the present and future
Did not exist there,
How could the present and the
Future be dependent on it?Without depending on the past,
Neither of the two could be established.
Therefore neither the present nor
The future could exist.By this very method, without substitution,
The remaining two; as well as …
Superior, inferior, average, etc.; and
Unity, etc., should be understood.A nonenduring time is not grasped
Nothing one could grasp as time
Could exist as enduring.
If time is not grasped, how it is known?If time depends on a entity
Nagarjuna
Then without an entity how could time exist?
Since there are no entities at all,
How could time exist?
According to Buddhist Philosophy, time appears in our consciousness during the process of knowing, which consists of the existence of matter first, then, the interaction between matters, then, functions of our consciousness (our senses), then, the process of knowing that occur in our consciousness and finally, the feeling that occurs in our consciousness.
Time therefore, is subjective because its existence depends upon our consciousness to acknowledge it. Time is relative to our consciousness through our perceptions of the world via our senses (Bunnag, 2016, p. 89).
Outline
- The goal of this chapter is provide an updated mechanism to understand time.
- Space Time. All existing all together right now.
- Our perception of time
- Buddhist view of time?
- Quote / exercises.
- Models for how to think of time.
- Exercises:
Special relativity eliminates the concept of absolute simultaneity and a universal present: according to the relativity of simultaneity, observers in different frames of reference can have different measurements of whether a given pair of events happened at the same time or at different times, with there being no physical basis for preferring one frame’s judgments over another’s.
- Our experience of time is one in which time continues its march inexorably without any change. Time and tide waits for no man we say. But is time really that consistent?
- Time moves at different tempos at lower and higher altitudes.
- Times moves slower as we increase our speed
- There isn’t a single moment in time that is the same all across the universe.
- THE ORDER OF TIME by Carlo Rovelli.
- Now is not clear. When I “see” you there is a nano-second difference between you and when I see you. Every time I “see” you I’m already behind where you are. It makes little difference here but if you were in Jupiter then you’re 4 hours away. If you’re moving then the now is in my future. Now doesn’t make sense simultaneously. It’s relevant to my frame of reference. Some of our major equations of physics have no distinction of time.
- Second principle of thermodynamics says entropy grows over time. Key distinction between past and future.
- For eg: music makes sense because it uses memory (a past event) and a prediction about the future. Because we listen to music a note at a time. So our brain is wired to understand and comprehend time. Our thinking requires time. The universe doesn’t have time.
- How our brain experiences time (there are two clocks):
- Einstein quote: “The only reason for time is so not everything takes place all together at the same time”
- Time is what clocks measure
- Julian Barbour, a British physicist, describes time as “a succession of pictures, a succession of snapshots, changing continuously one into another. I’m looking at you; you’re nodding your head. Without that change, we wouldn’t have any notion of time.”
- Now is a measure that is subjective. There isn’t a now that’s the same everywhere in the world. It depends on the reference point.
- No external time. No time in equations at the microphysics level
- For example, a car crash in London and another in New York appearing to happen at the same time to an observer on Earth, will appear to have occurred at slightly different times to an observer on an airplane flying between London and New York. Furthermore, if the two events cannot be causally connected (i.e. the time between event A and event B is less than the distance between them divided by the speed of light), depending on the state of motion, the crash in London may appear to occur first in a given frame, and the New York crash may appear to occur first in another. However, if the events are causally connected, precedence order is preserved in all frames of reference.
https://publicism.info/science/fabric/6.html
Block Universe Theory
A metaphor is the projector. The film is in the can and the projector is making its way through it. We’re the projector (the observer) at any given point making our way through the frames.
Henri Bergson:
Paul Dirac. According to Julian Barbour time is an emergent property. All there is a record and a perception of movement. We see a hand here and then a hand there. And we infer the passage of time between those two states. So time isn’t intrinsic. It’s like there isn’t wind but when the car moves there is a feeling of wind in our hair. We are moving through the snapshots and that move
Leibnitz: Space is the order of coexisting things. Time is the succession of coexisting things.
Buddhism and Time
- Dogen: Since time is always related with existence and existence is always related with momentary time, the past and the future are not existent time—the point at which existence and time come together—the present moment is the only existent time. Uji. Being/Time.
- Theravada Buddhism: Time arises with consciousness.
- Buddhist view appears to not be eternalism (Block Universe theory). It says instead that in each moment everything arises.
Sources
- https://iep.utm.edu/time/
- https://www.scientificamerican.com/article/your-brain-has-two-clocks/
- https://www.space.com/29859-the-illusion-of-time.html
- https://en.wikipedia.org/wiki/Relativity_of_simultaneity
- https://books.google.com/books?id=DNd2K6mxLpIC&pg=PA58&lpg=PA58&dq=spacetime+loaf&source=bl&ots=ue4KYTQhNV&sig=ACfU3U1KnqZtsbfDvKuARx_IZOZ23DHY-Q&hl=en&sa=X&ved=2ahUKEwjlv_rXpJnsAhW1ds0KHUEGB9UQ6AEwDHoECAEQAg#v=onepage&q=spacetime%20loaf&f=false
- https://bigthink.com/surprising-science/a-controversial-theory-claims-present-past-and-future-exist-at-the-same-time
- https://www.bbc.com/reel/video/p04s223f/physics-suggests-that-the-future-has-already-happened
- Why time is unreal: from Buddhism to J.E. McTaggart (Anawat Bunnag, 2016)