Time is a measurement of deterministic change
The Important
In networking, and everyday life, time intervals are measured by measuring the movement of objects in space: the movement of the earth around the sun (or as perceived, the sun around the earth), radiation from atoms, etc.
For getting stuff done, in the “real” world, all we really have to know is how we are measuring time, its precision, and its units.
What if we were trying to get stuff done in a less deterministic world, where the very location of something in space was probabilistic? What would the meaning of time be?
This is a thought piece, with no practical purpose other than to stimulate some thinking about the nature of time.
Summary
In one sense, we all experience and understand what time is. When the sun comes up, it is a new day. In another, we are not so sure, and honest/articulate physicists are clear about this. In our everyday experience though, time is the measurement of something moving through space in a deterministic way. Hence, the convenience of using light in the discussions of time, because it moves through space in a deterministic way (at a constant speed in a vacuum, and in known ways when refracted through other substances).
In a universe, or part of a universe, where position in space is probabilistic, where the very act of measuring something changes it, what would the implications for time be? Would time also be probabilistic? Would our understanding of that area of space, through a deterministic lens of change, then be challenged?
Where there is no movement at all, there would be no measured time, there would be no way to distinguish one interval of infinity, from another. Time might still exist, in a sense, but there would be no way of measuring it; at least not in the way we currently think about time; and if it can’t be measured…
Discussion
One of the simplest equations in physics, that most high school students would know, is:
Displacement/change in position (in meters) divided by change in time (in seconds) equals (average) velocity (in meters per second). This equation can be easily rearranged to:
In plain English, time, or more specifically the measured change in time, is the movement of an object in space, at an average velocity. More generally, some deterministic change.
It is worth stopping to think about that. If no objects moved through space, this measurement of time would not be possible. If objects did move through space, but we could not determine their average velocity, their position, or we could not measure it without changing it, then our understanding of time may be different.
For example, one of our earliest understandings of time came from the cyclical rising and setting of the sun. Imagine a world in which the cycle of rising and setting was completely random. What would that do to our concept of a day? What would that do to simple expressions like “Sunrise would be a good time to get started. Let’s meet then” or “We will need to work all day to get the job done”. When would we meet, how many hours would we be working for? It would be an unknown. The people concerned would simply have to wait and find out. What would a random rising and setting sun have done to the idea of a working day that arose under a more deterministic rising and setting of the sun?
Today, the most precise measurement of time comes from atomic clocks.
“Since 1968, the International System of Units (SI) has defined the second as the duration of 9192631770 cycles of radiation corresponding to the transition between two energy levels of the ground state of the caesium-133 atom. In 1997, the International Committee for Weights and Measures (CIPM) added that the preceding definition refers to a caesium atom at rest at a temperature of absolute zero.[15]
This definition makes the caesium oscillator the primary standard for time and frequency measurements, called the caesium standard. The definitions of other physical units, e.g., the volt and the metre, rely on the definition of the second.[16]”
Source: Atomic clock, Wikipedia
Atomic clocks work on the deterministic nature of radiation, over millions of cycles, commonly caesium. Specifically 9,192,631,770 cycles. What if those cycles were not deterministic? What if they were completely random? What if sometimes there were 9 million cycles in a “second” and in others there were 4 million? What if the number of cycles was completely random with no pattern? Then of course, this kind of clock would not be very useful given the way we think about time. At best, it could tell us that yes, there is a flow of time, because there has been a sequence of events. However, not very useful for articulating intervals of time.
Imagine a person quarantined in a metal box with no windows and no other objects in the metal box. This is not an ordinary person, this is a person that is only stimulated to thoughts and memories when something changes, when an event in space happens. This person also has none of the normal bodily functions of other people. The person sits in the dark room, nothing can be seen, no objects are moving through space, and therefore the person has no thoughts. Does time exist for the person quarantined in the metal box? There is existence in space, so in some sense there is time. There is no way however to observe changes in space, and therefore time. There are no intervals of time. There is just infinity.
Existence without change has no intervals of time and therefore is infinite.
Existence with change, but no way to observe deterministic change, is undefined, and to some extent probabilistic.
Existence with change, and a way to observe deterministic change, is existence within space and time as we know it.
Conclusion
The ideas of special and general relativity are ideas that apply to what we can easily observe and perceive. They rely on deterministic change, and deterministic ideas: meters, seconds, meters per second, etc. Networking, as we know it today, is also built on these ideas. GPS systems that correct for the difference between measured time on the surface of the earth and on a satellite; the speed of light in an optical fiber; the frequency of a processor. These ideas have served the networking industry well, and there is no reason, AFAIK, to forecast that any of these properties are likely to change; or even could change.
Are there parts of our universe that we can perceive, where there is no deterministic change? Perhaps. If there is, that would bring new challenges for networking, not the least of which, would be the very concept of measured time and time intervals; for some, perhaps even all, time itself would be changed.