Jim Al-Khalili says that he doesn’t have a ‘religious bone in his body’ – despite being brought up by a Shia Muslim father and a mother whom he describes as a ‘born again evangelical Christian’.

The scientist admits that his religiously diverse upbringing may mean he ended up ‘falling between two stools’. He also attributes his atheism to his scientific training: ‘My study of science, trying to find a non-theistic answer to the questions of how the universe is and our place in it, did probably push me away from religious faith.’

Studying science led to his job as a physics professor in Surrey. But Al- Khalili is best known for his role as a populariser of science on the airwaves, regularly hosting The Life Scientific on BBC Radio 4, in which he explores the lives of notable scientists.

He jokes that he nevertheless stands in the shadow of the BBC’s number one science commentator – ‘that Cox chap’ – with whom he has collaborated on TV documentaries. He laughingly recalls coming home for dinner to be told by his wife, ‘Here comes my second favourite TV presenter.’

Like Brian Cox, Al-Khalili has made no secret of his atheism. In fact, since 2013 he has been president of secular campaigning group the British Humanist Association. However, the broadcaster’s own brand of non-belief is far less abrasive than some of his scientific colleagues in the organisation. Whereas BHA vice-president Peter Atkins regularly describes belief in God as ‘intellectually lazy’, Al-Khalili says: ‘I’m not going to fall into that silly trap.

‘One of the reasons I was perhaps asked to be president of the British Humanist Association is that it was felt that I wouldn’t call someone with religious faith “stupid” as that’s naive and simplistic,’ he says.


Indeed, in conversation Al-Khalili is a model of civility and graciousness (he has described himself as a ‘cuddly’ atheist). What’s more, he takes religious questions seriously, although he’s never personally been able to be convinced there is anything beyond the universe we live in.

 ‘Theoretical physics involves thinking about the origins of the universe and the fundamental building blocks of everything. It’s made me more comfortable that I don’t need a supernatural explanation for the way things are.’

But what about the parts of science that seem open to supernatural explanations? In recent years, the discovery of cosmological ‘fine tuning’ – the precise calibration of the fundamental forces that govern our universe and allow life to exist – has both mystified and alarmed scientists. As physicist Paul Davies has said, ‘the impression of design is overwhelming’; Al-Khalili himself concedes that ‘it’s a powerful argument’.

In response (and to avoid theistic implications), many scientists have embraced a theory of ‘multiple universes’ to explain why ours may have just the right conditions to support life. Al-Khalili admits, however, that the theory is untestable and therefore doesn’t strictly qualify as scientific.

So why can’t a creating designer also be a valid explanation? At this point the physicist crosses from science to philosophy.

‘If we are looking for an explanation for the complexity and beauty of our universe, then why postulate something more complex, more beautiful?’ he asks. ‘You just push the argument one step back and make it even more insurmountable.’

It’s an objection also used by fellow atheist Richard Dawkins. Critics have said that the argument also shows why scientists don’t always make the best philosophers. We regularly detect design in other situations without being able to explain the designer, and in any case God could be defined as a very simple entity; possibly the most simple.


Al-Khalili is humble enough to admit that science will not necessarily furnish humanity with all the answers, either now or in the future. He also acknowledges that the mystery of why the physics of the universe seems to be written in mathematical laws that are waiting to be discovered is deeply mystifying. ‘It’s a huge philosophical question: “Why does nature speak the language of mathematics?” 

‘For me, not having an answer, not knowing, is fine. I would like to think I will find the answers. [Who knows] whether I will turn to religion later in life or have some epiphany? Maybe it comes down to what we as humans expect of how much we want to  understand.’


In the end, Al-Khalili seems sympathetic  to those who conclude that science and  nature point beyond themselves to an  ultimate source of reason, purpose and  meaning. He simply doesn’t believe he needs  to go beyond the science himself. 

‘I don’t require meaning to be ascribed  to some higher power. For me, it has to be  derived from the complexity of the human  mind. We create our own meaning – our  own motives and desires and emotions – but  it’s all embedded within the mind. Science at  the moment doesn’t give us all the answers,  but it doesn’t mean that there is something  over and above what we can rationally  understand.’ 

The universe by numbers

There are more than 30 fundamental forces and physical constants that appear to be exquisitely ‘finely tuned’ to allow the universe to exist and produce life. Here are three of them:

1:10120 The cosmological constant

This governs the expansion rate of the universe. If it varied from its actual value by 1 part in 10120 (1 with 120 zeros after it) then the universe would have expanded too rapidly for anything to form or collapsed back on itself.

1:1060 The gravitational constant

If the force of gravity varied by any more than this infinitesimally small number, then stars would burn either too hot or too cold for the chemical building blocks of life to form.

1:1037 The ratio of electrons to protons in the universe

If it varied from this incredibly sensitive balance, no galaxies, stars or planets would be able to form.


In the end, the president of the British  Humanists approaches the mystery of humans themselves with the same scientific approach he brings to his physics. As  human beings ‘we are programmed to seek  meaning’, he says, and some of us will seek  it beyond the stars. 

But there’s also a surprising admission  about faith from the atheist at the end our  conversation: ‘I’m envious (I guess that is the  right word), that it gives you meaning [and]  that you feel comfortable that things fall  into place with your faith. I’m still grasping  and trying to find out. I’m envious, but I’m nevertheless at peace with not knowing.’