Illustration by Mayank Chhaya
Facebook friend and fellow science aficionado Sharad Bailur’s update about an upcoming book has prompted today’s post. ‘The Island of Knowledge: The Limits of Science and the Search for Meaning’ by Marcelo Gleiser (Basic Books, a member of The Perseus Books Group. Copyright © 2014) appears to deal with many of the themes which have occupied my mind since my childhood.
In particular, an excerpt from the book carried by PBS’s Nova dwelling on the idea of ‘Now’ caught my attention because it is something I have frequently written about. The headline to the piece, which says ‘There is no Now’, jumped at me for the reason that would become obvious as you read the republication below of my own post.
Incidentally, Gleiser is the Appleton Professor of Natural Philosophy and Professor Physics and Astronomy at Dartmouth College. The book sounds fascinating and I intend to read it at some point soon.
Before I reproduce what I wrote in October and February last year, I would like to add an observation or two about ‘Now’. It has been my longstanding view that we all carry our own individual universes which may be similar to one another’s but are still uniquely our own. It is in this context that I think ‘Now’ is also individualized even though it may frequently converge and coincide with the ‘Now’ of others around us. I have also written about what I called shared approximation. Here is what I wrote in April this year, “…reality depends entirely on who you are and where you are. I can only approximately guess whether your reality is the same as or even largely similar to mine. It certainly feels so intuitively when it comes to larger realities such as sunrise or sunset within reasonably geographical proximity. We must all be conscious that there is no overarching reality that is common to us all. It is determined by so many other factors. The best we can do is to look for shared approximation.”
And here is what I wrote in October and February last year. (Even by my standards of self-absorption, I have surpassed myself by quoting myself so much. Oh, the onerous task of agreeing with myself about having agreed with myself earlier!)
With the discovery of what is believed to be the most distant and therefore the youngest galaxy to be detected yet, it is time for me to again refresh you about the absurdity of our idea of “Now.” There is no now and not just because now constantly becomes then. It is also because of the sheer scale of the universe that “Now” is a futile idea. It may work terrestrially within earthly proximities but it begins to lose its meaning rather quickly even within our own planetary neighborhood.
Astronomers have just announced that they have found the galaxy that was formed a mere 700 million years after the Big Bang. Called z8_GND_5296, the galaxy brings us our closest to the birth of the universe. When you consider that the age of the universe is determined to be 13.8 billion years, we are talking about its infancy. It has taken light from this particular galaxy 13.1 billion years to reach. So what we are seeing now is 13.1 billion years old. That’s what I mean the futility of now.
Before I get into that, a bit about how these distances are measured. As the universe expands and objects, including this galaxy, for ever recede from one another, the wavelength of the light from them increases. The increase makes that light look redder in color. Scientists call it the redshift which is measured as z. The higher the value of z, the farther it is from us. As an excerpt from this discovery explains in Nature magazine, “Of several dozen galaxies observed spectroscopically that are candidates for having a redshift (z) in excess of seven.” Excess of 7 for the redshift is considered a very high number indeed. The z8_GND_5296 has a redshift of 7.51, the highest so far and which scientists call “an epoch 700 million years after the Big Bang.”
What is extraordinary about this galaxy is that despite its very early formation in the aftermath of the universe it had a high star-formation rate. This was an unexpected finding. The rate was a factor of 100 greater than what we see in our own Milky Way.I think this is enough geektalk. Now on to esoteric talk.
From time to time, I have written about the paradox of what we call now actually not being now in the real sense, the last one being on February 10, this year.I think it is worth repeating in view of the latest finding. Here:
Does it strike you that everything in the universe is always communicating through its past and never its present? All phenomena that we experience are dated.
There is no real real time contact among objects considering that the time lag between any two object is considerable. Take for example, an object so predominant in our daily experience as the Sun. Considering that light from the Sun takes eight minutes to reach us here on the Earth, it means it is already dated information even if it so by just eight minutes.
As you begin to look beyond the interplanetary and into the intergalactic the distances become so vast that they no longer make sense on the human scale. If you don’t believe me check this out. At its closest the Venus is about 40 million kilometers from the Earth. Because of the elliptical orbits of the planets interplanetary distances vary extraordinarily. For instance, at its farthest the Venus is 261 million kilometers.Other than saying that it is extremely far, we cannot really sensibly comprehend how far.
Now consider Proxima Centauri, the star nearest to us. It is 40 trillion kilometers from us. To give you some measure of how far that is 40 trillion kilometers is 40 million million kilometers. Not that we can realistically grasp that either. So the nearest planet and the nearest star are separated from us by an incomprehensible magnitude.
It takes light, therefore information and data, 4.24 years to reach us from Proxima Centauri. That would be light traveling for over four years at the speed of 300,000 kilometers a second to arrive here. In other words, the information reaching us is nearly four and a quarter years old, even from the nearest star. Therefore, what we are looking at is Proxima Centauri as it was that long ago. If we want to know whether in the interregnum it got married, divorced, underwent a tummy tuck, won an Oscar, or simply turned into a red dwarf we have to wait nearly four and quarter years. What this means is that we are forever trapped in our universe’s past exchanging stale information.
One way to get around this problem of enormous datedness is to collectively agree that our past is in fact jointly our present and our present will be our joint future. I use our in a cosmic and not an earthly sense. All that we can do is together decide that the present is when we see it and not when it might have actually happened in relation to a particular event or an object.
Of course, we can also resign to the fact that there is no real present but perpetual past and there is no real future but nascent present. Moments are taking birth and perishing all the time. Our immediate anthropic present will never reconcile or converge with that of even our nearest planetary neighbor, the moon because of the time lag, albeit miniscule in this particular case.
For all practical purposes it does not really matter that we are never up-to-date about the universe because we have to live with what appears before us. If Proxima Centauri was atomized at this present Earth moment, what material difference would it make to us in the way we process that information four and a quarter years into the future? For you and I Proxima Centauri will appear to have disintegrated only in June of 2017. It will be real present for us when we experience it then even though for the star it would be its past.
There are two kinds of present, one that is real present as experienced by the object in question and the other as experienced by those away from it. This time lag exists even on our own planet but it is so small that as human we cannot perceive it.
One way to respond to the post today is to ask me if I forgot to take my medicine. The more mature way would be to ponder yourself. It is not my intention to freak you out but to merely remind you that the concept of past, present and future is so strange at the scale of the universe. Perhaps the idea of a multiverse is supposed to mean that every object in the universe is a multiverse in and of itself in so much as their timelines never really converge.
So next time you have an argument with someone simply say this: “Let’s just say that we are on different timelines. Our present do not seem to converge.” Or try saying, “Your light has not yet reached me. It is the time lag and not us.”
When it comes to anyone other than oneself, we can all only hope for the bare minimum timeline convergence.Friendships and romances develop during that timeline convergence.
Is it any wonder then that only you genuinely know and converge with yourself? This is what Oscar Wilde called a lifelong romance.