The materials scientist whose letter from the Queen arrived in shreds
Sir Colin Humphreys is known for his pioneering work in LED technology. In parallel with his scientific career, he’s spent 50 years studying the Bible. As he (reluctantly) approaches retirement from Cambridge, he reflects on some formative experiences.
My room looks over open fields. It’s on the ground floor of the Department of Material Science and Metallurgy. The uninterrupted view of trees and flying birds helps me compose my thoughts not only about science, but also about the wonderful world in which we live.
Next door is the Cambridge Centre for Gallium Nitride. In this centre, which I founded in 2000, researchers from all over the world are developing ways in which gallium nitride can be used to make a wide range of technologies more energy efficient.
Cambridge is in many ways a place of privilege. My early years were strikingly different. I was born with a deformity in both feet and had a major operation when I was two. After the operation, I was in plaster for six months and wore leg irons till I was 12. They were contraptions to straighten my legs.
Home was a small house in Luton. We were really quite poor. The house didn’t even have an inside lavatory. Despite the leg irons, I joined a street gang which fought with other gangs. Some of the kids had air pistols. I was often the one who got caught. My father decided we should move to a better part of town.
My father took me to enrol in a new primary school. The headmistress said I’d be going into the bottom of three classes. Her decision was based on the dismal record of my previous school. My father insisted I should be in the top group. She asked me some general knowledge questions, none of which I could answer.
He announced that he wasn’t moving from his chair until I was put in the top group. The headmistress agreed to give me a month’s trial. I started bottom of the class but began to make progress. I realised what a lot I had to learn to keep up with the brightest. Had my father not been so brave, I mightn’t have got into grammar school.
I passed the 11-plus exam and went to Luton Grammar School for Boys. Pupils from a wide range of backgrounds were at the school, which enabled social mobility on quite a large scale. In the sixth form I specialised in maths, physics and chemistry. I regretted stopping biology, French and music — but not art at which I was hopeless.
It wasn’t school alone that put me on track for a career in science. When I was eight my parents took me to London. Walking down the Strand, I spotted a shop called Watkins & Doncaster that sold everything to do with moths and butterflies. We went in and I begged my parents to buy some butterfly eggs but they wouldn’t.
Eventually, my parents gave in and we ordered some moth eggs from India. I made a simulated steaming jungle out of cardboard, wet blotting paper and an electric lamp underneath. When the eggs arrived, I tended them until they hatched. The caterpillars wandered about our living room and made cocoons containing chrysalises on the curtains.
I went on to breed other moths and butterflies — including the Atlas moth. I taught myself their Latin names. I researched the plants that caterpillars ate in their native countries and found related plants in the UK to feed them on. I think this laid the foundations of my complex multi-million pound research projects.
With a state scholarship I went to Imperial College to take a degree in physics. I went on to do further research at Cambridge, Oxford and Liverpool, where I became Head of Materials Engineering. I forged links with industry and, with colleagues, made advances in understanding the structure of materials using electron microscopy.
As a materials scientist, I’m best known for my work in LED technology. When we first put forward the idea that gallium nitride could be used as a light source throughout the world, people said it was nonsense. The costs were prohibitive.
We developed a new way of making low-cost gallium nitride LEDs. Our technology was transferred to Plessey, which is now manufacturing millions of low-cost LEDs at its factory in Plymouth. These are sold to manufacturers of LED bulbs. Plessey estimates that our technology reduces the price of LEDs by five to ten times.
The key was finding a way to grow gallium nitride on silicon rather than sapphire. Once we’d done this, we could focus on making the development a commercial reality. People said it would take two years for us to transfer our technology to Plessey. We did it in eight weeks.
In 2010 I was knighted. When I received a letter saying that I would be knighted in the Queen’s Birthday Honours List for “Services to Science”, I thought it was a student prank. The letter had arrived torn to bits inside a plastic bag with a note from the Royal Mail apologising that it had been damaged in its sorting machine.
I put the pieces of the letter together like a three-dimensional jigsaw puzzle. I was still convinced it was a student joke but my wife encouraged me to phone to check it wasn’t a hoax. It was genuine. I accepted the knighthood with great pleasure. Who or what organisation proposed me, I still don’t know.
Alongside my work in materials science, I’ve always studied the Bible. My parents were Creationists who believed that God made the world in seven days and I accepted this. When I was doing my A levels, and learnt about radio carbon dating, I began to question my parents’ beliefs. I never confronted them but I think they knew that I’d rejected Creationism.
At university I rediscovered my Christian faith. People are surprised to meet a scientist who’s also a believer — but there are lots of us. I did have a letter that began: “Cobbler stick to thy last.” Once a Chinese student knocked on my door and said: “I’m told that you believe in God. That’s impossible.” It led to a lively discussion.
I’ve found no conflict between science and the Bible. Scientists and Christians are both seekers after truth. If there is a God, then the God who reveals himself to us through the Universe, which he created, and which scientists study, is the same God who reveals himself to us through the Bible.
According to my research into the Gospels, the Last Supper was on Wednesday. My argument is based on a combination of Biblical, historical and astronomical research. At first sight, the four Gospels appear to contradict themselves over the date of the Last Supper. But they were using different calendars.
I can’t quite believe that I’ve reached the age of 76. Under Cambridge University rules I have to retire soon. Fixed retirement ages are not something I agree with. People like me, who are lucky to have good health, may still have a lot to contribute. I’ve already had offers of projects from several universities, both here and overseas.
Richard Dawkins has done a great job with his anti-God arguments. One of the things I want to do when I have more time is write a popular book that puts across the arguments for the existence of God. I’ve been very fortunate to have spent 30 years of my life in Cambridge with its pool of talent. There’s a lot more I want to do.
This profile is part of our This Cambridge Life series.
Main photograph by Howard Guest