Chapter 9 Stories about time

 Time is an Illusion. Lunch time doubly so.

The Hitchhikers Guide to the Galaxy by Douglas Adams

What is time?

This chapter is here to show how many dimensions of time, different people believe in.

Simple one-dimensional time

Most people, including physicists before relativity, believed that there was only one dimension of time, and you can only move forwards in time. There have been many hypotheses that time travel could exist, and that time has more than one dimension, which I will go into later.

Most scientists quote the fact that the time dimension is very different than space dimensions. In space directions, you can always go forwards and backwards. There is no experiment where objects cannot start in one place and not be able to return to the same place at a later time. On the other hand, there are very few experiments that allow anything to go forwards in time and come back to the same time.

However, in 2016, physicists performed experiments that have the same effect as light moving backwards in time.

Scientists send light backwards in time!

No scientist is claiming that the light actually went backwards in time. Just that the quantum mechanics allows events to happen that look exactly the same as if a photon of light had travelled back in time.

Whether light actually moved back in time, no one knows, and no professional scientist is going to claim that this experiment proves that time travel is possible.

It relies on quantum effects that are only likely for tiny particles, and they become incredibly improbable even for particles as "large" as atoms.

Relativity's three dimensions of time

The theory of relativity allows people to move at different rates through time. To explain this, physicists have had to measure time in three dimensions.

For a full explanation, please look at the 3:27:34 video,

The Evolution of Time (Director's Cut).

For an abridged version read on.

Firstly, the present moment ticks by at the same moment for everyone, This is the old one-dimensional time.

However, if objects are moving at different speeds.  The faster you are travelling, the slower your clock runs.

So the periods slow down as you go faster.

Also, gravity changes the rate time passes too. Geostationary satellites go through time faster than we do because they are further from Earth.



As you can see, the formulas are not the same. That is the only reason to present them here.

As, the length of a periods change due to speed or gravity, so the present moment happens at apparently different times on each traveller's clock. This personal time is independent of the present moment.

This is the second dimension of time.

The periods dilate, and your advancement through history slows down or contracts differently, depending on your speed and the gravity applied to you in different ways. So not only is time passing independent to the current moment, but it is also the passage of each period that is independent, depending on which effects are combining to define the periods and their passage.

This leads to the three dimensions of time: the current moment, the current length of a period of time, and the rate of passage of time.

Because of this, the passage of time may be able to run backwards, even though the present moment only moves forward.

Theories about time travel.

No self-consistent theoretical physics framework currently allows time travel. Although many incomplete theories do exist and no one has scientifically proven that it cannot exist, only that is exceedingly unlikely. They have proven that time travel could only happen in bizarre situations, such as wormholes, where spacetime is bent through another dimension so that two remote points are connected and you can step between them. Apart from deep within the quantum scale of things, there is no scientific expectation of this being possible, certainly not at the macro human scale.

However, the topic is frequently visited by science fiction writers, and some scientists indulge in hypotheses just because, "Would it not be great if ..."

The most well-known thought experiment is the grandfather paradox:

If I travelled back in time and stopped my grandfather and grandmother meeting or killed one before my parents were born then I would never have been born and so I could never have gone back to disrupt the past.

There are two major groups of fictional stories, where time travel does exist that handle the grandfather paradox differently.

1. In the first is the "It has already happened." version. Because you travelled back in time, your presence in your families history has already occurred and what for you is your future has already happened in the past. This means you cannot kill your grandfather in your future because you did not do it in your past, they are one and the same thing. This version means that history is immutable, it cannot change.
2. The second is the multiverse version. When you travel back in time you, you immediately create a new branch of history, a new universe.  In the first branch your very recent past, you suddenly disappeared from one universe, creating a new branch of the Multiverse, without you, and then suddenly you appeared in a different one. This is an entire multiverse where you just mysteriously appeared from nowhere. So, whatever you do to your grandparents in the new universe, stays happened in the new history so you can stop the new you from being born.
   
   In all probability just by having visited that universe for a second, you will change the sperm that met the egg when your grandparents made love, and so it would not be your life that would change but a total stranger's who is no less a child of your grandparents. All the tribe that follows on from that change would be different.

Transporting something as big as a human through a wormhole is, to say the least, not an expected scientific event. So far, we may have got a photon through one, but we are still not hopeful about getting an atom through, let alone a human. Heisenberg dampeners are pure fiction.

Given our understanding of the Multiverse, history seems exceedingly changeable, so the Multiverse version seems eminently more reasonable.

So, if time travel is possible, you will never be able to return to the time you left because you left and that change will have changed the universe compared if you had not. But that is true of every decision you make in the whole of your life.

In both versions, the passage of time and the number of time dimensions remains the same. It is just in the second a new universe is discovered that was not there before, as happens every time you make a decision. So films such as Ground Hog Day are repeated loops back to a new universe that was the same as the one before except at each iteration the person travelling back has a little bit more knowledge.

The philosophers infinite time dimensions

As mentioned in the chapter on eternal life. It was suggested that whatever the abstract existence of the Universe or Multiverse entails it is just a space admittedly infinite that can be looked at from the outside. This is the first step in an infinite chain.

Assuming there is a being that can look at the multiverse from the outside then he, she or it would look at things in a particular order and time would occur for the observer outside of our existence. Regardless of which order, the observer looked at the events in our existence.

In the same way, the existence in which that observer exists is also abstract and could be looked at from the outside by another observe in his, her or its version of time.

This leads to an infinite nesting of existences and observers with their own version of time being looked by more observers. With an infinitely deep nesting of observers.

This infinite nesting of conscious time is attributed to J. W. Dunne. Some physicists also believe that there is an infinite number of time dimensions too.

It also fits with my infinite image of God who is conscious at many levels and that intelligence can only be expressed with a passage of time.

For intelligence, you need to be able to respond intelligently to new situations.

1. Events must occur, first;
2. The intelligence must think about them, second;
3. Then intelligence may act on them, third.

If we ever can look at things in infinite detail. Then we, from within the Multiverse, could look at the whole Multiverse from the inside too. We could see ourselves staring at the Multiverse in the middle of which would be us looking at the same Multiverse ad infinitum. Not that we would have to, because we could be looking at different branches of the Multiverse and see other parts of it, or see ourselves looking at other parts.

Certainly, our thoughts can think of the infinitely small and large, but we do tend to forget things when we put too much information in our squidgy brains.