Is it polite to ask a photon its age?

From time to time I read reviews and become a frustrated person. The last such review of a science fiction, time travel story drove me almost to distraction as it strove to criticise the underlying science of the book based on what Niels Bohr said about wave or particle nature. In fact the review was rather well written and balanced and it is not for me to have a go at the review or the reviewer per se (in fact, it seems to me that to anything much bigger than an electron, the duality issues is rather academic). What gets me is the utter nonsense we spout in the belief that we can somehow judge the plausibility of science fiction, it strikes me as the ultimate in oxymoronic comments. Working in Copenhagen, it seems rude of me to say anything against this magnificent city’s famous inhabitant. The name Bohr is plastered on to many a building and sign and rightly so, but he is both regarded as a genius and as a man whose grip on normality was almost metaphysical at best. In reality he was not always correct and some of his theories survive whilst others have been surpassed. That other great physicist of the last century, Feynman, is very clear in his excellently engaging lectures that a theory holds up until the point that it does not fit the data, at which point it is wrong.
So if we choose to judge the veracity of a science fiction story on the basis of a single physicists work then we have missed the whole point. Science is a journey of exploration of our ignorance and only one thing is generally true, the moment we think that we have the system sussed is the moment that we are most incorrect. Take time travel, an interesting topic that drives the imagination to all sorts of lengths. The problem is that we do not even seem to understand what time is, why we perceive it and why we only go in one direction. We travel through time at roughly one second per second, but why is that? At the fundamental level, when the world is reduced to equations on a black board, our metaphor indicates that the universe does not need time to go one way. On the smallest scale time can go forward and backward. Feynman spent some time on a theory that required that one particle set off backwards in time in order to make the system work. It is only our preconceptions about time that make this sound odd. The theory solved some issues, although I cannot say whether it still holds as a theory. My understanding is that time has a directionality driven by the flow of energy from simple to chaotic systems. Like the way a teenager’s bedroom will tend to flow from tidy to untidy; the reverse is possible but the amount of energy required makes it implausible.
We perceive time as a series of sequential sensory impressions that are then laid down as memory. We think that it is instantaneous but it is not. Photons hit receptors in the eye and rhodopsin changes shape, TM5 moves and a signal is set off inside the cell that becomes a chemically transmitted nerve impulse and not doubt synapses fire and somewhere in the kilo of mush that sits up there the physics turned chemistry becomes the biology of a memory. Kobilka did a lot of work to show how photons lead to shape changes in the receptors in the eye. Originally his work showed that the shape change took 18 seconds; luckily we are not that far behind reality. In later experiments he could show that this effect was in fact much more rapid. It tells us though that our concept of now is in reality a concept of then. Kobilka went on to win a Nobel last year.
Even more challenging is the notion that the photon had to travel a certain time to get to our eyes. There are several interesting notions here and the most mind boggling is another I read of in Feynman papers that perhaps the photon does not set off until it ‘knows’ it will be captured. This morning as I ran in the remaining star light I am reminded of the huge distances and the many ages that the photons I am seeing have travelled. Could they really have known I would look? I am seeing into the past by looking straight up, and yet Feynman would say that the photon only set off when the path to my eye was open. Does the photon have a shorter path that we do not understand, we do not know. We do not know the age of the photon and probably it is not polite to ask.
My point, if there is one, is that many of the theories that we have of the universe are works in progress. We should be open to surprises. Our imagination is one of our greatest assets and from the imagination comes both the nascent theories of the future but also the science fiction of today. How many inventions have been developed to mimic the great science fiction series of the sixties, for example? We should not try to rationalize science fiction otherwise it would already be science fact. Time travel might happen one day, and perhaps it already has. Perhaps we already have the closed causal loops.
There is a final salient point about science fiction in this rant and that is the need to maintain a level where the reader is dragged along in their suspended sense of disbelief. Too many clumsy moves and the mood is lost and a neat story becomes a painful journey.

In Duality Inc. J. Thomas Beaton creates a science fiction thriller in which nothing is as it seems. It does not contain time travel but it does contain difficult concepts of the transportation of ‘self’ from one world to another. In a thought provoking turn pager Beaton’s hero has to attempt to overcome tremendous odds to save humanity. The leap of faith in this book is not the science but the ability of a fairly random chap to be able to rapidly evolve into a world saving super chap. It is the stuff of dreams, just like the one where you score the winning goal at the world cup having been plucked from obscurity off the local field because your keep ups looked just spiffing. While I always have issues with this type of leap, this transformation in character, it makes for a compelling, high energy reading experience that does make one turn the pages. It is a book to entertain oneself with and to enjoy at face value. There is a deeper undertone of secrets hidden and forces beyond our worldly knowledge at play and this makes the storyline fresh and intriguing.


In this second instalment, Johnson picks up exactly where he left off from book one. The perils of time travel are laid bare in the continuing farce of our heroes attempting and just failing to put right the things that they put wrong in the first place. The harder they try to reset the timeline, the more badly wrong the timeline gets kicked out of shape. The story evolves and the plot thickens, deepens and broadens and eventually reaches clear waters of ‘reason’. It is an entertaining story and a good read.

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4 thoughts on “Is it polite to ask a photon its age?

  1. Fascintaing stuff, theoretical science – and yet some of it owes its existence to science fiction. Time Travel, Geosynchronous orbits and carbon nanotubes all began within the pages of novels. Even MP3 players would not exist without the fertile imagination of Star Trek. So any criticism of science fiction should always end with the phrase …’just not at this time.’
    Oh – Hawking proposes that a working Time Machine can never be ‘sent back’ beyond the point at which it was constructed. So by that reckoning, closed causality loops cannot be created until a machine is actually built.
    But Stephen has admitted to mistakes in the past… 🙂

    1. Quite right on the Hawking front, but what fun would it be to travel back to last Tuesday for the majority of people? If time travel is possible, let us hope that either some distant ancestor invented it or that the great professor is incorrect!

      1. UFOs are time travelling visitors from the future. Think about it – UFOs are already documented, so they won’t change the future by being here plus they are content to observe from a distance, tickle the odd tourist and kidnap a cow or two for future research. If I ever fall off a toilet whilst hanging a clock and invent time travel, I will make the machine look like a UFO.

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