Professor Colin Humphreys, CBE, FREng
Interview by Nigel Bovey
To enter Colin Humphreys’ study is to walk into an Aladdin’s cave. It is crammed with scientific toys, models and gizmos. Some are leaving gifts from his former students, others are of his own making. Colin, who is the Goldsmiths’ Professor of Material Science at Cambridge University, travels the world to share his knowledge. Aware of the need to cut globe-trotting carbon footprints, he is working on aircraft engine alloys with Rolls-Royce.
The plan is to find materials to develop fuel-efficient, high-temperature aero engines. From a carrier bag he pulls his latest project, a credit-card-sized torch with an amazingly bright white light. It’s the sort of thing adventurous boys and girls the world over would like for Christmas.
Colin, what’s so special about this torch?
We are trying to replace all the lighting in the world with this. My main area of research is on gallium nitride, which emits brilliant lights of different colours. Gallium nitride is not a natural compound. We have to make it, which is quite a challenge. White light-emitting diodes (LEDs) are already in use in the flashes of mobile camera phones and bicycle lights. I am working on higher-quality white LEDs which give off a less harsh light by mimicking natural daylight. The hope is that they will replace the standard light bulb, even the energy-efficient ones.
Lighting consumes 20% of all electricity output. With LEDs we could halve that figure. Electricity prices, CO2 emissions and the replacement of power stations could be cut by 10%. That’s a bigger reduction than would be saved through wind power. Because higher-quality white LEDs mimic daylight, people who suffer from lack of sunshine in the winter – seasonal affective disorder – would be healthier. The bulbs last up to 60 years. Low-cost, long-life, high-quality, environmentally friendly lighting will mean that these LEDs are the ultimate light source.
That sounds a little bit like ‘Tomorrow’s World’ – where supposedly life-changing inventions were showcased on TV, never to see the light of day again. What are the chances that your gallium nitride light will catch on?
Oh, it will happen. Semiconductor companies are behind this and light-bulb manufacturers are following. When Philips, for example, produced LED flash units for camera phones, sales rose to 100m units in less than three years. Audi are using LEDs in daytime headlights. BMW and Lexus are to follow suit with main headlights. LED lighting is used on yachts. Last year, the front of Buckingham Palace was illuminated with LED lighting for less than the cost of boiling a kettle. Getting this technology into people’s homes depends on reducing production costs, but it will happen.
Besides being used in what we might call luxury goods, what other implications does your LED lighting have?
It could radically change life in the developing world. The average person in India has less than 3% of the lighting of the average person in America. To get even 20% in conventional ways would mean building six times the number of power stations. But LED lighting doesn’t need connection to a national grid. It can run off a solar panel. So people who can’t work once the sun goes down will be able to have light and it will cost nothing to run.
We’ve also discovered that at deep ultraviolet levels, gallium nitride kills all viruses and bacteria. In the developing world, impure water is a bigger killer than Aids. One idea would be to have an array of ultraviolet LEDs on the inside of waterpipes. The water would still look filthy, but it would be bug-free and safe to drink. Another application would be to kill hospital superbugs or to purify air. It is difficult work and some way off yet, but it will be possible.
Colin, when did you become a Christian?
My parents were Christians and as a lad I went to church and Sunday school. When I was about 14, I decided to be a Christian. But when I went to study at Imperial College, London, I threw it overboard. For about a year I said, ‘I am not a Christian: it is all fairy stories.’
One night, one of my flatmates asked me to go to church with him. I knew that some good-looking girls went to this church, so I agreed. After the service, a group of us went back to the minister’s house. A week or two later I went again and was walking home from the minister’s house with one of my colleagues when he said that he wanted to be a Christian and I should tell him how to go about it. I thought to myself: ‘What do I say? He thinks I am a Christian. I know I’m not. Do I tell him I’m not a Christian and spoil his chance of faith? Or do I tell him what to pray but not have any conviction in it myself?’ In the end I told him to speak with the minister. But it got me thinking.
I sat up all night. His question challenged me. Was I a Christian or not? That night I decided I would become a Christian, and I started reading the Gospels and Christian books. I confirmed this decision later. I later learnt that my friend had seen the minister and become a Christian.
How does your faith affect your science?
I hope it affects the way I deal with people and the conflicts which can arise with people when you are a scientist. I am also delighted that I am working on something which will directly benefit people. For many years that wasn’t the case, and it troubled me.
And how has science had an impact on your faith?
I think scientists see the world slightly differently. To me, Christianity is a very logical and reasonable faith. When I read the Bible, I tend to look for natural explanations. That doesn’t mean I don’t believe in miracles but that I think God often works in and through nature to achieve his purpose. Often the miracle is in the timing of an event. And there are some things, like the resurrection of Jesus or the virgin birth, for which we can’t give a scientific explanation and which certainly are miracles.
What is your working definition of ‘miracle’?
I go with Aristotle. He spoke about prime movers and agents. He said that God is the prime mover and agents can be things like natural events. So how do you know an event is a miracle or not? It is determined, said Aristotle, by the timing. If, for example, you look at the story of the Israelites crossing the Red Sea, the Bible says that Moses stretched out his hand over the waters all that night. God sent a strong east wind to drive the waters back. So it was a natural event – there’s no hint of God sending an angel or clicking his fingers. God was using nature to accomplish his purpose. But that it was done at the precise moment when the Israelites were surrounded and about to be crushed by the Egyptians makes it a miracle.
There’s another principle at work, which we can see if we look at the time Jesus walked on water. Often people describe this as a miracle by saying that God stopped gravity operating, otherwise Jesus would have sunk. I look at it another way. Rather than the natural phenomenon being suspended, why not say God provided an additional force which upheld Jesus? That way, God doesn’t break his own rules to perform a miracle.
So, for you, is God someone who is more likely to use what he has already created rather than someone who is forever intervening to get people out of trouble?
It is a difficult subject. If prayer is meaningful – if prayer can change things – then there has to be flexibility in the system. I think that some things are fixed. God plans things. I believe, for example, that God planned that Jesus would come into history at a certain point of time and would be crucified when he was. I also think that God leaves a number of things flexible, that he interacts with us to achieve his purposes.
For example, like everyone else I’ve made good decisions and wrong decisions. If I had always made the right decisions, my life would have followed a certain course, which may well have been a better course. But there again I believe God works with us, if we let him, to make the best of a wrong decision. Because God has given us free will, life cannot all be rigidly planned. For example, the Bible says that God wills for the whole world to be saved. But it hasn’t happened yet because humans exercise their free will and reject God. And God allows that.
Do you apply this mix of direct divine intervention and God allowing ‘natural’ processes to continue to the way life has come about?
As a Christian, I believe God is in charge. He worked with his created order for the emergence of life, including humans. He planned from the beginning that humans would emerge at a time and in a way of his choosing. I was brought up to believe that the Earth was around 6,000 years old. It was one of the reasons why, when I went to university, I thought the faith wasn’t true. I have a great deal of sympathy with creationists because I know they are very genuine people. But I now believe that evolution is the way God developed life.
Why do some people see evolution as an attack on their Christian faith?
If someone interprets the early chapters of Genesis and concludes that the Earth was created around 4,000 BC and evolution requires longer for life to develop, then both accounts cannot be right. Evolution does not say that humans evolved from apes. It says that humans and apes share a common origin. For non-believers, evolution is taken as evidence that life is nothing more than a series of blind chances and is, therefore, meaningless. From a faith perspective, I see evolution consisting of a lot of events which look like chance but which are part of a process guided by God.
The creation accounts in Genesis include the idea that humans are made in the image of God. What do you understand by this?
I am tempted by the way the ancient Egyptians used the same phrase. The Egyptians had many gods. They made statues and images of their gods, and worshipped them. To them, these images were representatives of God on earth. I like the idea that in the Genesis account, humankind was made to be the representative of God on earth.
Sometimes the public gets worried that one group wants to be more than God’s representatives, when scientists play God. Are you worried that scientists can go too far?
Scientists will increasingly have the ability to play God, especially in the biological realm. We will be able to do remarkable things which can be used for good or evil. It is vital that there is moral guidance. There is also a great need for Christians to be at the forefront of science in the future.
In your work you’re trying to solve the problems of the future. But in your spare time you’ve also been researching events of past, particularly the star of Bethlehem. What have you discovered? Is the biblical account surrounding the birth of Jesus true or is it a story that tells a truth?
I take it as being literally true. In Matthew’s Gospel, the account is sandwiched between a genealogy of Jesus in chapter one and the coming of John the Baptist in chapter three. Both of these are rooting Jesus in history. Chapter two opens with, ‘After Jesus was born in Bethlehem in Judaea, during the time of King Herod…’ King Herod reigned from 40-4 BC. There was another Bethlehem, but Matthew specifically identifies ‘Bethlehem in Judaea’. The account has all the hallmarks of a story that is meant to be taken literally. Jesus is being placed in history and geography – real time, real places, real people.
There are three possible explanations for the star. One, it was a mythical star, an invention that didn’t really exist. Two, it was a miraculous star, one which God created just for that occasion. Three, it was a real astronomical object. I firmly believe that God could have produced a miraculous star, but with ancient Egyptian and Babylonian literature containing stories of new and special stars. As far back as the 1600s, Austrian mathematician and astronomer Johannes Kepler started applying his newly developed laws of planetary motion to identify the star of Bethlehem. My approach was: Is there a known star which fits as precisely as possible the description we have in Matthew’s Gospel?
But how much workable scientific data does Matthew’s account give us?
A lot of commonly recited details about the story don’t come from the Bible at all, but from Christmas carols. The Bible doesn’t say that the star guided the men. That’s from ‘As With Gladness’ and ‘We Three Kings’. This raises the question of the star-followers. Were they ‘wise men’? Were they kings? The ‘Magi’ – as the Gospel calls them – were almost certainly Babylonian astrologers-cum-astronomers. Unlike today, back then people didn’t distinguish between astrology and astronomy.
In Matthew, the star has three distinctive, unusual characteristics. Firstly, Herod asked the Magi the exact time the star had appeared. This strongly suggests it was a newly appeared star. Secondly, it appeared to have travelled in the sky because the Magi first saw the star in the east and then went to Jerusalem. Then from Jerusalem they travelled due south to Bethlehem, where they saw the star ahead of them. Thirdly, as they went towards Bethlehem, it is said the star stood over the place where the child was.
If it was a new star, there are a limited number of options it could be: a nova, a supernova, a meteor, a shooting star or a comet. If the star travelled in the sky, it couldn’t have been a nova or supernova, which explodes but does not trace across the sky. Comets, on the other hand, whatever their orbit, travel one or two degrees a day through the sky against the star background.
The clue is the phrase, ‘the star stood over the place where the child was’. Many Christmas card designers have interpreted ‘the place where the child was’ as the stable, but my understanding of the original Greek is that it could equally be taken to mean the town of Bethlehem. Either way it works, as the Magi travelled from Jerusalem to Bethlehem.
How common a phenomenon, though, is it for a comet to appear to stand over a certain place?
I found only two references in ancient literature to stars standing over places. One was by the Roman historian Cassius Dio, who said a star stood over Rome. This is regarded as a reference to Halley’s Comet and dates the occasion as 11 or 12 BC. The other comes from the Jewish historian Josephus, who talks about an event which occurred in AD 64. He said a star like a sword stood over Jerusalem. We know from other ancient literature that comets were frequently described as swords because they can have a long pointing tail. Historians agree that Josephus was describing a comet. In fact, through Chinese astronomical records, we can identify this particular comet. So, on the two occasions when a star is said to have stood over a place, it was a comet. It is very likely, therefore, that the star of Bethlehem was a comet and that its tail pointed out Bethlehem.
What does identifying the star as verifiably real prove?
It is an indication that Jesus really lived. It helps place him in history. It means we can get an idea of when he was born. Chinese astronomers always recorded whether a comet had a short or a long tail. To the Chinese, the length of the tail and its position in the sky were significant. A long-tailed comet was known as a broom star. To them, it signified the sweeping out of the old and the start of a new era. Between 20 BC and AD 10 they recorded three comets. In this period there was just one long-tailed comet. It appeared in 5 BC and was visible for 70 days. King Herod died in 4 BC, so the star from the Chinese record fits the time frame well.
Speaking of time frames (and acknowledging the AD/BC contrivance by which the birth of Christ is usually dated around 4 BC) how does the appearance of the 5 BC comet fit with the biblical account that Herod, wanting to wipe out the threat of a rival king, ordered the killing of all boys aged two and under?
This is Herod taking no chances. The question is: Why did the Magi come to Jerusalem to ask about a new king in the first place? I think this is down to a sequence of three events. In 7 BC, Saturn and Jupiter lined up three times: astronomers call this a triple conjunction of planets. (Some people consider this as the star of Bethlehem.) In that year, Jupiter and Saturn came very close together three times. To astronomers-cum-astrologers at the time, that would have been very significant. Babylonians worshipped Saturn as the main god and Jupiter as his son. The symbolism of Saturn and Jupiter lining up closely together and then separating was that a son of God was to be born. For this to happen three times was a sign of the importance of this birth.
Secondly, the Babylonians associated the constellation of Pisces with Israel. When the planets lined up, they did so with Pisces in the background. This was taken as a message that the son of God would be born in Israel. Some years ago, archaeologists found a clay tablet called the Star Almanac of Sippar, at a place called Sippar, about 30 miles from Babylon. It records the conjunction of Saturn and Jupiter as happening in 7 BC. The clay tablet is now in the British Museum. Whether it was a prophecy given in advance or something written after the event, we don’t know; but it is significant that people considered the lining up of Saturn and Jupiter in Pisces important enough to write down. In 6 BC, Mars joined Saturn and Jupiter in the sky, and all the planets were very close together. This is called a planetary massing. Mars was the sign of a mighty warrior, so the message was that this would be a mighty king.
The question for the Magi was: When is this going to happen? This is answered when the comet appears in 5 BC, because a comet in the east meant to the Babylonians that the event will happen now. They then make their way to Jerusalem and tell Herod, ‘We have seen his star in the east’. Matthew’s Gospel records that Herod questioned them about the ‘exact time’ the star had appeared. The fact that Herod ordered the death of all boys aged two and under suggests that he – along with the Magi – considered the 7 BC conjunction of the planets as a sign of the birth of a new king.
When the ‘wise men’ saw the star they recognised its significance, they followed it and they discovered Jesus. Why is the star of Bethlehem so special to you?
To me, it speaks of how God uses natural phenomena. He could have made a special, miraculous star, but he didn’t. He used what he’d already created: planets and stars. Significantly, God chose to use Gentiles – foreigners – to herald the birth of Jesus. This speaks of God being inclusive. He sent Jesus for the whole world and whole-world citizens are represented in the events of his birth. Being able to identify and date the star adds scientific weight to the fact that Jesus was born where and when the Bible says.
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Is it possible to believe in God in the modern era of scientific discovery? In a series of in-depth interviews, scientists from fields as diverse as botany, immunology and physics talk about their scientific research and their faith in God.
All the interviews on these pages were conducted by Major Nigel Bovey and first appeared in The Salvation Army newspaper The War Cry © The Salvation Army. For further reprint permission, please contact The War Cry.
Read these interviews and others in God, the Big Bang and Bunsen-burning Issues by Nigel Bovey (£8.99, Authentic Media)
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