Each day we wake up to our alarm, going to school, university or work. After that we have time for the things we love or things we have to do and at night we sleep again. We have fixed events each day: breakfast, lunch and dinner, maybe a workout routine, meeting someone and and and. We also measure and point to time with clocks and calendars. So, what is time?
A year consists of twelve months, a month of four weeks, a week of seven days and so on. Time is represented through a cycle. The duration of a year is when the earth travelled around the sun once. A month when the moon circles the earth once. And, a day is the period of time in which the earth completes one rotation around its own axis. With our calenders and clocks we measure how much time passed, we can check where the present is and we can point to events in the past and future. For that we need a reference point. Most of us probably use the Gregorian Calendar and we use the birth of Christ (though it was probably calculated a bit off) as the reference point. A year of the Gregorian Calendar consists of 365.2425 days.
Physical and psychological time
We locate events which happen in our universe with time. For example my birthday was on the 2nd November 1995. I was born in Darmstadt. With these informations you can pinpoint this event with 4 sets of numbers: 11/02/1995 or 02.11.1995 (date), 49.878708 (latitude), 8.646927 (longitude) and 148m/485ft above sea level. You can locate every event in this universe if you have four sets of numbers. This is what we call the physical time. You can imagine time just as the fourth dimension. But if we look at time like this we shouldn’t be able to feel time. There should be no direction in which time moves. This could imply that everything is fixed. Nothing we do will have an impact on the outcome cause everything is already there on this 4 dimensional world…
But we feel time instead of seeing it like we can see the other 3 dimensions (width, height and depth). We feel “duration”. The passing of time. We remember the past and move to a uncertain future connected by the present we live in. The time we feel depends on our mind. This “duration” exists in our consciousness. This is the psychological time.
So, time moves in our mind. We remember the past, live in the present and try to build our uncertain future. But we can only be sure about the present. All we do is in the now and even the now passes so fast and becomes the past. All that really matters should be the now…
Three arrows of time
There are these two concepts of time: the physical (time as part of the spacetime -> the 4th dimension) and psychological (the feeling of time/duration we have in our mind) time. Both exist. And it’s difficult to say that only one matters. Either way, time has a direction which is described by the arrows of time:
There is the thermodynamic arrow of time which is based on the 2nd law of thermodynamics: in an isolated system, entropy tends to increase with time. Our universe for example turned out pretty nice and smooth. For us to be able to live on this earth is such luck. If something starts out so neatly and smooth it will be hard to stay in this “perfect state” as time passes by. I think we can see entropy in the way we change the climate of our earth and make it unbearable to live on or we know that stars will collapse and become black holes as time goes by.
The cosmological arrow of time points in the direction of the universe’s expansion. So, basically from the center of the universe (wherever that might be) into every direction. It’s like drawing dots everywhere on a balloon and then blowing up the balloon. The balloon will expand in every direction and the gaps between the dots (stars and planets and other space stuff) will get bigger and bigger. This is the cosmological arrow. The direction of the expansion.
And there is also our subjective sense of the direction of time, the psychological arrow of time. Like I described before. We remember our past, accumulating memories of the past as time moves linearly from our memory-filled past to our memory-absent future.
Big Bang and Big Crush?
But when did time start? Will it have an end?
Scientists say that time started with the Big Bang. The birth of our universe. Before there was nothing. With nothing to happen there is no sense for time. Nobody to feel the time and without events there is no use to measure time. If there is a creator of our universe maybe he was able to feel time before the birth of our universe. Maybe he/she/it got bored and that’s why our universe was created…
And like said before, our universe is expanding since the Big Bang. At the Big Bang our universe was so compact. As time passed by it expanded and got as big as we know it now and it still keeps expanding. But every object in the universe has a mass and with that every object has a gravitational force. All the objects attract the “edge of the universe”. When the rate of the expansion speed is not big enough anymore the gravitational force will retract our universe. The universe will get smaller and smaller. This deflation of the universe is called the Big Crunch.
So, when everything is retracting that means that there will be no more expansion of the universe and it will contract instead. The cosmological arrow of time will be reversed then. Will that also happen to the psychological arrow of time and the thermodynamic arrow of time?
Instead of increasing entropy we would have negentropy. This means everything will become more in order. Like said before, we destroy our earth or stars get to old and become black holes. Instead of that we would have our destroyed earth going back to be more like the way it was and black holes disappear and become stars again.
We might also live our life backwards. From death to birth. We will remember the future and move to the uncertain past? That could happen…
This is all so crazy and I do not know how to make sense of it all. It’s crazily interesting but it barely makes sense. For example: why do we have the direction of time though the universe will go backwards anyway to its original state? You can think hours about this stuff and it can be fun thinking about things like this but you wont find an answer. All I know now is that I feel time, that time is also a dimension and that I live in the now. All I can really control is the now. I try to live life to the fullest, not to regret things. There is no sense in regretting the past or being afraid of the future. You can’t change the past and the future is uncertain. All there is to do is to use the now you have and make the best out of it. This does not mean that I don’t look at my past or wonder about my future. I just don’t want to lose myself being afraid of what i should do so that I don’t regret my past or be afraid of the outcome of the future. So, let me end with a quote:
“We are living in a culture entirely hypnotized by the illusion of time, in which the so-called present moment is felt as nothing but an infintesimal hairline between an all-powerfully causative past and an absorbingly important future. We have no present. Our consciousness is almost completely preoccupied with memory and expectation. We do not realize that there never was, is, nor will be any other experience than present experience. We are therefore out of touch with reality. We confuse the world as talked about, described, and measured with the world which actually is. We are sick with a fascination for the useful tools of names and numbers, of symbols, signs, conceptions and ideas.”
Alan Wilson Watts
khoala sees the world 