Time as we use it is a cultural construct made by us people who are living on this planet in this part of the cosmos that we occupy. Time as we have invented it does not exist as a given. That is not to say that this invention is not extremely useful to us. It is important in all elements of life and is a fundamental element of our scientific developments.
Other beings at other planets could come up with totally different cultural constructs. So, does time as a unique phenomenon exists?
First, if we look at our time construct, Einstein through his relatively theory has already proven that time indeed is relative. It depends where you are and to what you measure it.
If you look at an expanding universe you could put a time element to it, so as such time as a phenomenon could exist. However, if you look at other phenomena in the cosmos such as the fact that stronger gravity slows down time and the unexplained behaviour of time in blackholes we need to question this. But is is safe to state that because of these sort of behaviours in space there is not such a thing as universal time in the cosmos, or at least we haven’t been able to detect or formulate this, even not theoretically.
Quantum mechanics is becoming more and more interesting to further study and try to understand some of the fundamental elements of our cosmos, including space time. A key element here is the ‘now’ moment. It is rather easy to define to past and the future, but what exactly is the now? As a matter of fact the past and the future don’t exist (not anymore or not yet) the only thing that exists is the now. If we apply quantum mechanics to this, we can nearly infinitely divide now, by doing so scientists have defined quantum time and Planck time. In relation to space we are also talking about quantum gravity.
What we also know is that at this quantum level, ‘normal’ physics do not necessary apply. We can observe strange behaviour, but we do not understand this. At quantum levels, photons often show wave-like behaviour that for example allow them to tunnel through fixed structures. Another interesting phenomena is entanglement, here two elementary particles that arise from a single reaction share complementary properties (for example electrons with a spin + and a spin -), the value of which is only determined at the moment of observation of one of the particles. The moment an observation shows that a particle has a certain value, the value of the other entangled particle is immediately established. Even though the particles are thousands of light years apart. If you measure a particle that has spin +, then you know for sure that the entangled particle has a spin -. The fact that a variable of an entangled elementary particle has two values simultaneously is the basic principle on which quantum computers are built.
Obviously, these observations throw our physical concepts totally in disarray. We will not start to understand these processes by just continuing to work from the mathematical and scientific foundations that we have developed so far. Excuse the pun but we do need a quantum leap to bring us on a different trajectory to study our cosmos and fundamental issues such as a s time and space.
Suddenly science fiction becomes interesting as well if we look at time travel, time warps, multiple universes, parallel worlds and so on.
Other disciplines such as neurobiology, where we are observing similar quantum mechanisms at work could also be an avenue that could help us to understand what these quantum processes are all about. If we start looking into this we can ask if time perhaps is a reflection of our own consciousness. Is it real at all?