Time has no Tense

Physics has two theories as far as time is concerned but these are at a fundamental impasse. One is proposed by quantum mechanics according to which time has a unidirectional flow from past to present, and it is absolute and universal.  The general theory of relativity on the other hand supposes that time is relative to our reference frame. It speaks that space and time are interwoven which can bend or curve in presence of heavy masses. Imagine your head on a soft pillow creating a dip in it. This is what a heavy mass does to the fabric of space-time.

Time dilates in presence of strong gravity. In other words, the clocks tick slower near huge masses. Experiments on Earth and in the spacecrafts have confirmed this prediction with remarkable accuracy. In other words, we age slightly faster  on Earth than in Space Stations. Similarly, Global Positioning systems rely on general relativity because time flows differently for satellites than it flows for the people on Earth.  Thus time is much more than what a clock shows.

A new study published in May this year, in the journal of Physical review A suggests that the illusion of time is woven at a quantum level. The equations of physics do not show which events are happening right now and all moments are equally real. Suppose my friend wants to make a surprise visit to me from thousands of kilometers.

I do not know that she has left from her home today. In other words I do not know some parts of my present.  She will arrive at my place in 3 days. So I also do not know my near future. By the same logic, I am not aware of the distant future.

However, someone having an aerial view of the country or the continent has a fair idea of who is where and when.  For him, nothing has happened or will happen. It is all out there. He can trace the parts of an event at various points in the space time matrix. Someone’s past is my present and may be my present is the future of someone or something else.

For instance the light of sun that keeps reaching us uninterrupted is actually 8 minutes and 20 seconds old. In other words if sun stops glowing, we will be in dark after more than 8 minutes. This also lends further credence to block theory of Universe supported by general relativity, according to which past, present, and future all exist simultaneously and are equally real.

The block theory of universe is also known as eternalism. It is a model of four-dimensional block where all events - past, present, and future - coexist simultaneously. The block has three spatial dimensions and one temporal dimension, or time. The block is filled with every event that has ever happened, including birth and death. In other words, the happenings are frozen and unchanging. If our life is a movie, space is the DVD.

As biological beings, our brain has an element of memory which gives us a sense of distinct past.  We seem to be living in the present and going to our future, which has not yet seemingly unfolded.  This distinction of past, present and future is a mental construct and according to Einstein, a stubbornly persistent illusion.

Ever wonder why the glorious Quran often uses the past tense to convey the future, such as the Day of Resurrection. This may be to encourage readers to commit to good deeds and avoid bad ones. This may also be as a way of reinforcement and certitude. However, it can also be for us to consider that Qiyamah has already happened.

The subject of space-time continuum was first discussed in the late 19 century. Essentially scientist are debating whether time really exists at all or may be that the past, present and the future exist on the same plane, at the same instance.

This may also throw a hint to explain why the Quran sometimes talk of future events as if those have already happened. Or why the Prophet (PBUH), on his trip to the heavens met prophets of the past. From the theological perspective, we are advised not to curse time. People generally inveigh against time when disasters such as death, old age, loss of money, health or opportunity etc., happen. Therefore say not ‘Woe to time’ for God is time. However, the actual word used in the tradition is (al-dahr) meaning vicissitudes of time.

Time is an abstract entity and does not have a physical existence. This had made some physicists question whether it even exists.  Psychologically, time looks like a real entity because we see all sorts of changes around us.

We grow old and our hair turns grey. But age may just be a self devised number or calculation because fundamentally time may not be real.  It may not even be required in the deepest formulations of laws of nature.  Yet the world seems to be temporal.

In the words of Adam Frank, a theoretical physicist; "May be the only way to understand time is not from some God's-eye perspective, but from the inside, from a perspective of asking what is it about life that manifests such an appearance of the world."

Dr. Qudsia Gani, Head Department of Physics GDC Pattan, Baramulla