Updated: April 23, 2010
We have talked about time before. I wrote a piece where I explained in non-geeky terms why it is impossible to travel through time. In the original article, I assumed that time is a sort of a peaceful variable that you can bunch into the equations without much fuss. In a way, I gave time scalar properties. However, time as a scalar does not explain many physical phenomena, like that of atom energy states. To human mind, the concept of discrete energy levels is very hard to understand and accept. But what if time is not a scalar?
Today, I'll propose my own idea of what time is, purely speculative and possibly completely wrong. But it does not matter. Thinking outside the box, if you treat time not as a linear variable, but a sort of an elastic sheet wrapping everything inside our Universe, lots of mysterious problems become trivial issues. There's the String theory and the six extra dimensions wrapped around the basic four, but why not make it even simpler.
Time has eluded a formal definition so far. It's an integral, inseparable part of all kinds of physical theories, but actually, all it does is make the various matrices a bit bigger. For all practical purposes, it's another element that makes the equation a little nicer and helps explains all kinds of phenomena that defy interpretations. Time is also a major philosophical topic.
I have given this quite a bit of thought recently. I do not like the classic 4D model, where Time is a dimension. This implies that time can be measured, which is not quite true, because time is relative and depends on the reference frame used. Furthermore, for the time being, Time is continuous and infinitely divisible, which makes it less likely to be notches on a measurement tape - and more the measurement tape itself. Just like Speed of Light, Time should not be treated as a quantity, it should be treated as a quality. It's a property of the medium, dictating the basic physical laws.
So here's a novel idea I've come up with.
Time is the aggregation of events. Now, what an event would be?
Event is any change of a particle state, either in its energy state or its displacement, within the accepted Uncertainty Principle limits. A sequence of events for any given particle is a thread. A mesh of these threads defines the Fabric of Time. However, treating events as dots reduces the event to a single-dimension problem. Instead, we use the particle energy to define the event intensity and the particle 3D vector as event orientation.
A visual representation of this idea would be a tree-like chain of lights, where distance between the lights defines the physical displacement, in 3D, normalized against the speed of light, and the intensity signifies the change in particle energy. The absolute zero energy state would be the vacuum rest energy.
Take a look at the image to the left:
The image is showing four different particle Time threads; points of varying intensity and diameter symbolically define particle energy during a given event; the white lines are a 2D representation of event orientation, where the actual length of the lines is what we would call time in human terms - a link connecting two events. The threads are slightly blurred because of the Uncertainty Principle. The image does not show any relation between particles, but it could be there - it's described by particle Hamiltonians and/or wavefunctions.
What about particles that do not change their 3D position? If the Fabric of Time was merely a spatial quality, then yes, our threads would be meaningless. But we're not discussing displacement against a set of static coordinates. Time threads are visual interpretation of events, relative to the medium they define, in our case the Universe. In a static 2D world, the image above would be a genuine representation of Time. Particles that do not move would remain single points of light.
In our Universe, which is expanding (most likely), static, non-interacting particles would be vectors normal to the expansion sphere, showing us the curvature of the space at any given moment. Which fits well with both the logical and mathematical definition of time as the glue that binds the little coordinates. But due to the non-linear nature of our Universe, it also defines the shape of the medium contained.
In a way, this is similar to all those funny diagrams that show particle collision in LHC and suchlike:
What remains to be done is to wrap the Time threads around an expanding 3D/4D surface that has the same behavioral properties as our Universe, and you get the actual map of Time, for each and every particle, all combined. Naturally, on a quantum scale, the Time threads would have fluctuations.
So you would probably get something like this. Not sure about the tail, where you have the exponential cosmic inflation. But Time wise, the shape could very well be different from the actual shape of the Universe, which would then be described by different time-space metrics. The cross-section of the inflating Time bubble could then be a perfect circle, but it could also be any other shape dictated by the medium.
Anyhow, the Universe is definitely not round, more sort of a hyperbolic cylinder/cone, but I guess you grasp the idea. A decent visual representation of this concept is the NASA Universe timeline graph (public domain):
The only thing left is to define the minimal energy intensity and the change delta, i.e. what constitutes as an event. To avoid the time dependence paradox, since you cannot measure time inside time, we need a different kind of reference. Planck time sounds like a good idea.
In a way, my webbed Fabric of Time model does sound a bit like String theory, and you have event properties instead of string worldsheets.
Furthermore, reducing the eventhood to Planck time means the time is fragmented to very small units, completely contained by particle energy and 3D position, In other words, the underlying structure of the Universe, normalized against the logic of time, is a stack of Lego blocks, of certain size and color, where each block is an event. Block length would be Planck time. Trying to sample the event on a scale smaller than the block length, if such a thing was physically possible, would appear as if the Time went still.
Again, imagine the actual shape to be an ever-expanding (or self-inflating) hyperbolic cylinder/cone, and then it all makes perfect sense. For example, discrete energy states are events, Lego blocks if you will, a change in the event intensity, which occurs within Planck time.
Now, if there are different types of Fabric, then you can dictate the behavior of the Universe. For instance, dark matter may only be nothing more than a different type of Fabric that does not mix with the standard kind, which makes its time events isolated. The same goes for anti-matter.
Similarly, statistical probability might be nothing more than fluctuations in Time threads. Then, Time might also be cyclic, which could explain why Universe has a non-centric structure. What about knots and forks in the threads? What if they get interwoven? What happens to threads of two particles colliding and annihilating one another? Do these threads come undone? Does this mean the entire thread, all the way back, are no longer relevant? Or do new particles inherit them? Well, we will talk about all these in a separate article.
Lastly, we can also talk about temperature. In a way, temperature tells us what the Universe is trying to do, entropy wise. But it could also depend on Time, with the absolute zero being a state where there are no changes in Time threads. Negative temperature or negative time would be situations where there's no relation between two events of the same particle, leading us back to the good ole discussion about time travel. Next time, fellas.
Meanwhile, if you want to read a few cunning articles:
Time on Wikipedia
Minkowski Space on Wikipedia
Special Relativity on Wikipedia
I hope this helps you understand a little better what time is. I may be completely wrong, but since this topic has eluded the brightest minds in physics for the past ... forever, then I'm allowed a little slack when it comes to tackling such a delicate topic. But you must admit it's a decent idea.
In the next article, I'll try to answer the question of the Grandfather Paradox, using my own model. By introducing all sorts of problems into the Fabric of Time, I'll try to answer all kinds of temporal related Voodoo magic ideas, including those of time travel.