In thy light do we see light
Sermon preached in St Salvator's Chapel, St Andrews on 17th January 2010 by Professor Wilson Sibbett
Readings: Psalm 36: 5 - 10 & 1 Corinthians 12: 4 - 12 & 13: 11 - 12
In the autumn of each year, especially in early October, I have a few eminent research friends who admit to staying close to a telephone just in case a call is received from the Nobel Prize Panel in Sweden. I hasten to say that I am not in this sub-group and in 2009 I don't believe that I missed the call! I was, however, delighted to see that the Panel awarded the 2009 Nobel Prize for Physics to CHARLES KAO for his pioneering research work on the glass fibre developments that laid the foundations for practical optical communications. Without straying into technicalities and jargon, I can tell you that he had a vision that provided the stimulus for the subsequent technological development of the broadband internet connections that are accessible to all of us today.
My theme today is directed towards light as a communication medium where I can draw upon some insights from my own field of research. Key components of an optical communications network not only include optical fibres with a birth date of 1966 (when Kao and co-workers published their definitive paper on the subject) but also lasers and in this year of 2010 we celebrate the fiftieth anniversary of the discovery of the laser! Just in case you get lost along the way with some of the more scientific connections, could I just say at the outset that using the text of, In thy light do we see light, (taken from the lectionary entry for today) I shall try to correlate some aspects of Christian-based communication with a few areas of optical physics and astronomy.
Reel of optical fibre as a visual aid: As a contrast to the relatively complex microwave-based communications that were being worked on in the 1960s, Charlie Kao's original assertion was that data-carrying beams of light propagating through strands of glass could form the basis for a communication technology that would be much superior to the alternative microwave or millimetre-wave technologies. But, before optical fibres could be considered as suitable communication links, a few major shortcomings had to be addressed such as loss due to impurities in the glass itself. In 1965 if a beam of laser light was passed through a 3m-long piece of the then existing glass fibre, the intensity would be reduced to half. Kao argued that if the transparency could be increased by 50 times then communication networks based on optical fibres would become feasible and practical. Within 10-15 years the transparency of glass fibre had actually improved by a factor of 5000! In fact, laser light can now travel through 15 kilometres (or, 9 miles and 3 furlongs) of optical fibre before its intensity drops to half.
So now for your first parallel - perhaps this thinking on transparency for efficient communication was not too different from that of reformers such as Martin Luther when a more direct channel was being advocated for communicating the Christian message to everyday folk! With this reformation thrust there would be much less influence and interference from church practices which for many were much too formalized and indirect. Indeed, something along these lines could conceivably have been spoken from this famous pulpit by John Knox because a widened access to God¿s word was one of the key aspirations and defining differentiators as seen by the Scottish Covenanters who believed that all people should be able to have direct and unimpeded communications to God through Christ - in other words, transparency.
Transparency - So how has this advance in fibre technology happened and what parallels might it have with communicating the Christian message?
Well, in the case of the optical fibre strands it was a matter of improving the quality of the constituent glass so that the light would not be subject to less absorption from impurities. But, it is important to appreciate that that the glass in optical fibres is not pure and still contains some level of impurity. My message to you is that perfection is not a prerequisite to be being practical and useful in life and in God's service. Maybe, therefore, you can see a parallel where we ought to deal with some features in our lives that represent impediments to communication with our God!
Perhaps this could be linked with the demand from Jesus that we read about in
Luke 6:42.
"Or how can you say to your brother, 'Brother, let me take out the speck that is in your eye,' when you yourself do not see the log that is in your own eye? You hypocrite, first take the log out of your own eye, and then you will see clearly to take out the speck that is in your brother's eye."
Stained or doped glass.
Those of you who are looking Southwards can appreciate readily, even on a winter January day, the stunning visual impact of the beautiful stained glass windows in this Chapel. Here the glass has been doped or 'stained' deliberately to facilitate some selectivity in the transmission of daylight, with the result that we can have a communication channel based around a combination of artistic expression, craftsmanship and materials science. For example, oxides of gold, copper and cobalt when added to molten glass permit the transmission of the red, green and blue primary colours. Thus, while a red robe may be perceived visually as a velvet fabric, we cannot resolve the presence of any gold particles. This is a clear example of where the overall picture is more informative than an elemental analysis!
There is perhaps another parallel here - Would it not be better for each of us to allow God's all-pervading light to shine through the character of those individuals who we might consider to be rather compromised, before we make a judgement of their relative values to society, the church, or perhaps even to God himself! In fact, it is this failure to see the overall picture that often represents one of the most serious weaknesses that we can have. It would, therefore, be better if we followed a path in life that enabled us to understand and translate more clearly the essence of today¿s text, In thy light do we see light
Doping of optical fibres - Now let me go back to my reel of optical fibre. I said that after propagation in 15km of modern optical fibres, the signal intensity or strength is reduced by a factor of two. So, what about long-range optical communications such as those between here and North America where the distances are several thousand kilometres? You can see that several 15km spans would reduce the signal intensity markedly and so some measure is required to restore the intensity of the data carrying light beams. To overcome this inevitable loss of signal strength, the technological solution is to splice in fibre-optic-based amplifier elements at regular spans to 'regenerate' the signal intensity level. Interestingly, just as we can have stained glass for our windows, discrete lengths of optical fibres that are doped selectively with elements such as erbium enable us to build 'in-line optical amplifiers'. Incidentally, these optical amplifiers are 'powered' by small dedicated semiconductor lasers that have operational lifetimes that exceed 100 years! So, in a manner that is similar to the signal enhancement of my voice by an audio amplifier, we can have the amplification of signals in an optical communications network. Indeed, university and industry research groups here in the UK pioneered the development of optical fibre amplifiers in the 1980s. Importantly, also, there is a key feature that is common to the transmission properties of the optical transmission fibres and the fibre-based amplifier elements. This is that each can handle a wide range of spectral bandwidth which, in more simple terms, means that many optical channels (like the distinct stations on a radio) can be accommodated. In today's technology, we can have up to one thousand optical channels through a process called wavelength division multiplexing.
So, here again we are exploiting a medium that is 'stained' to achieve this result and I believe this to offer potential for drawing some useful parallels. Amplification or exposition of the message is surely a role that is undertaken faithfully by ministers throughout the Christian Church. Also, in the service of the church more generally there are many rather imperfect folk who can assist in relaying the primary thrusts of the Christian message.
As a follow up to this, we can relate the complementary components of a stained glass window and the many wavelength or colour bands in an optical fibre communications network to the spiritual gifts mentioned in today¿s reading. Specifically, in Corinthians12:4, the Apostle Paul is telling us:
Now there are varieties of gifts, but the same Spirit; 5and there are varieties of service, but the same Lord; 6and there are varieties of working, but it is the same God who inspires them all in every one.
This could even be packaged as the 'added value' that is very much a benchmark of modern assessments and evaluations - including university research! You don't need me to spell out the obvious local, denominational and global implications for extrapolation towards the wider mission and responsibilities of the Christian church.
Some of you might be surprised that I have not so far made any reference to St Paul's words recorded in the authorized version of the 1 Corinthians 13:12 as - For now we see through a glass, darkly; but then face to face . In the verses read today from the RSV, we have the translation that does not relate to cloudy or imperfect glass but instead refers to a poor mirror image. For now we see in a mirror dimly. Can be related readily to St Paul's day when mirrors may have been rather crudely polished brass but of course mirror technology has also come a long way since then. We can have many very sophisticated mirrors in terms of their reflectivity and versatility features.
The Hubble Space Telescope (HST) - To illustrate my point, I will use the example of the Hubble space telescope which represented a massive commitment to research in astronomy. A telescope in space was considered to be essential to overcome the image-degrading effects of turbulence in the upper atmosphere that so compromised the quality of observations of stellar objects made from ground level. The HST has had its last upgrade/refurbishment in 2009 and so its operating life is now running out. Looking to the future, there is something called adaptive optics that involves the use of intense laser beams that may enable a new generation of ground-based telescopes with a capability of producing images that would be just as clear and sharp as those taken in space. You might well ask, 'how can this be?' Well, the scale of the atmospheric turbulence is first sampled through back scatter from the laser beam that is directed skywards and then the surface profiles of multi-segment 'deformable' telescope mirrors are manipulated accordingly to undo precisely the effects of phase distortions experienced by this artificial or guide star. The result can therefore be sharply focused images of stars taken from earth!
So, the parallel is simply, that we as imperfect beings can take the 'world's distortions' of the truth and be inspired through faith as a community of individuals to convey a message that enables others, as well as ourselves, to perceive a meaning for life that is both clearly focused and true.
When Dr Martin Luther King said, "I've had a dream...' it could be seen in his face that he had a vision for the future that took its inspiration from a 'spiritual guide star'. Indeed, someone who could say with such conviction, I have a dream that one day on the red hills of Georgia, the sons of former slaves and the sons of former slave owners will be able to sit down together at the table of brotherhood, had, I believe, a truly inspired and reconstructed view of what it meant to have a living Christian faith. Moreover, when he went on to say, I have a dream that one day even the state of Mississippi, a state sweltering with the heat of injustice, sweltering with the heat of oppression, will be transformed into an oasis of freedom and justice, he was showing himself to be a wonderful role model for adaptive reflection such that through him a new aspiration could begin to take shape for an entire nation!
In conclusion, therefore, by dealing with the communication of God's message through offering ourselves as vessels for either the transmission or reflection of His light, then we can provide a living and worthy translation of the psalmist's vision when he said,
'In thy light do we see light.'