Notes from Session 4: Quantum mechanics and the unpredictability of science

Last week we looked at science that seems incompatible with the miracle stories in the Bible. The science is clearly an accurate description of how the universe works. Personally I believe that most of the time God doesn’t interfere with these fundamental laws of nature – but that, as someone said last week – his love for us is such that he did intervene in one, singular and supreme way when Jesus became human.

The only way I can deal with miracles is by accepting that in the person of Jesus, God acted contrary to scientific laws in miracles…sometimes to reveal just who he was, sometimes out of compassion, sometimes for reasons totally beyond me…

After Jesus’ ascension such miracles still happened by the work of the Holy Spirit through the Apostles – and perhaps still do. They don’t mean that Newton was wrong…just that God is bigger.

Back to this week’s science…

I need to start by explaining a couple of ideas that will be needed later.

  1. Things can exist as either continuous or discrete variables. You might remember this from maths lessons on drawing graphs.

Example – the time it takes someone to run 100m – can have any value. 10sec…11sec and anything in between – our watch might not be accurate enough to measure it – but it is possible. How tall a person is – 160cm…180cm and anything in between. There are an infinite number of possibilities of how tall we can be – impossible to count.

A discrete variable is one that can only have certain values…number of people in a car. You could have 1,2,3,4… but you can’t have 1½ people in your car.

  • Number of heads from flipping a coin x times
  • Number of siblings you have

Until about 1900 energy, including light energy, was thought to be continuous – you should be able to have any amount of energy.

  1. All matter, or stuff, is made up of tiny particles called atoms. These are the smallest bit you can have and it still be gold, copper, carbon, hydrogen etc. But these atoms are made up of smaller bits (particles) found in all matter – neutrons and protons – which are relatively big and heavy, and tiny electrons which whizz around.

Well – it is impossible to look at dramatic discoveries in science without thinking about quantum physics – following Newton and others, by about 1900 classical physics seemed to have everything explained – until scientists started looking at things on a much smaller scale. Then there were things that could be measured/observed that just couldn’t be explained by physics as it was – by Newton’s laws

One was the photoelectric effect.

If you get thin metal foils and focus light beams on them – electrons are given off.  The light has enough energy in it to knock electrons out of the metal. You can measure how many come off and how fast they are going as they come off.

Classical physics saw light as waves – which means light waves have amplitude – how much energy in each wave, and frequency – how often the waves come.

It suggests that bigger waves (brighter light) hitting the metal should mean electrons coming off with more energy – faster.

It suggests that a higher frequency of waves should mean more electrons coming off every second.

BUT what actually happened was that higher frequency of light increased the speed – the energy in each electron, but brighter light meant more electrons per second. The opposite.

Einstein finally got round this by using the idea that the light is actually a set of bits of light – called photons. In other words – light comes as particles not waves. Bits of light. Quanta. If we go back to the start – it is discrete, not continuous.

If you look at it like this – then the frequency is how much energy each bit has – and the brightness is how many bits you have.

One bit of light (photon) is taken in by one electron. If it has enough energy it knocks the electron out of the metal. If it has lots of energy – it knocks it out with more force – but since it is taken in by one electron – it still only knocks one out.

If the light is brighter (has more energy) – this means more photons – so more electrons knocked out – but all at the same speed.

The important point for us is perhaps that it seemed – even to Einstein and other physicists – ridiculous that light comes as particles – as though it is bits of stuff – but the maths only works if it is.

Quantum physics had arrived. It attempts to describe how particles in atoms move – and how this can explain things that are observed in experiments. It looked to start with at electrons in atoms and how to explain results from experiments.

Here is Rutherford’s model from about 1908. But then more was observed…First electrons appear to orbit the nucleus only in particular energy levels – if they move between them, quanta of energy are given out. Then it was found you needed to know the size, shape and direction of orbit. But even this didn’t explain everything – you needed another quantum number, which was which way the electron was spinning – but for the maths to work it had to spin twice round to get back to where it started…*

Things got worse when it was discovered that particles such as electrons – which have a mass and electrical charge and could bounce off things – could also act like a wave where the particle appears to be all around the atom at the same time – and its electrical charge is somehow spread out.

Then there is Heisenberg’s uncertainty principle – which says that the more you know about how fast a particle is travelling – the less you can know about where it is – and the other way round. Classical physics let you be sure of both – that’s how it worked.

And for some it has the problem that you can no longer draw or imagine a model – much of quantum physics can only be described in terms of maths – but it works to explain things.

Even more incomprehensible is the idea of ‘entanglement’. Scientists discovered a quantum property of electrons called ‘spin’, which has 2 possible directions, called up or down. Pairs of electrons are given off together, which can flip between up and down – but there always has to be one of each, but you don’t know which is which. But once the spin of one is measured – it is then fixed (in other words we affect something by measuring it) and more bizarrely so is the spin of the other one. This has been shown to be true even if the particles are measured once they are enormous distances apart – if you measure one as spin up before the other reaches its detector, then the other has to be spin down…and there is no way a message could get from one to the other at the speed required. How does it know?

Then there is chaos – our inability to predict the weather any significance time into the future. As we attempt to make the information we measure more and more precise – measure smaller and smaller things – the uncertainty of quantum mechanics takes over…

All this means that science is inherently unpredictable which gives the possibility of God acting within the unpredictability – rather than contravening the laws of nature. It also raises the possibility that science does not have all the answers.

Want to leave you with a couple of quotes from some of the people who developed quantum physics…

Niels Bohr said, “Anyone who is not shocked by quantum theory has not understood it.”

Werner Heisenberg – “The reality we can put into words is never reality itself.”

Sounds suspiciously like St Augustine  – If you can understand it – it’s not God.

And finally another beautiful one from Heisenberg.

“The first gulp from the glass of natural sciences will turn you into an atheist, but at the bottom of the glass God is waiting for you.”

Bible Study – A ‘model’ for God?

In John 3: 1-10 we read about Nicodemus – a Pharisee who probably thinks that he has his religion sorted. He is attracted to Jesus who tells him that he needs to be born again. When Nicodemus doesn’t understand, one of the things Jesus says is…

“The wind blows where it chooses, and you hear the sound of it, but you do not know where it comes from or where it goes. So it is with everyone who is born of the spirit.”

What do you think Jesus might have meant by this?

In Paul’s letter to the Corinthians he writes:

“For now we see in a mirror, dimly, but then we will see face to face. Now I know only in part; then I will know fully, even as I have been fully known.”

What do you think Paul might have meant by this?

In our creeds we affirm that we believe in God – Father, Son and Holy Spirit. The idea of the Trinity is not described explicitly anywhere in the bible. It is something the church agreed on after hundreds of years of discussion, argument, prayer. Like quantum mechanics it needed a whole new vocabulary – one God in 3 persons.

We could think of the idea of the Trinity like the scientific model for the structure of an atom – it fits the evidence we have – from the bible, from our lives – and it is the best humans can come up with at the moment. But it may well not be the whole truth…

What does the picture of Trinity tell you about God?

Do you find it a helpful picture?

Do you have any problems with the picture of the Trinity?


Notes from Session 3: Newton, mechanics and the predictability of science

In the previous two sessions we looked at scientific theories that challenged a literal reading of the bible. Today I want to look at some science that was developed earlier than either of those – perhaps took longer to get to the wider public but in the long run had an even greater effect on beliefs.

So today we are going to have a look at some physics. We are particularly going to look at motion – how things move, how they come to move etc. I am sure many of you are better physicists than I am – feel free to correct me – but what I am really interested in tonight is the effect the physics, and the maths that goes with it, had on our view of the world. So I will be generalizing and simplifying – to try to say something useful in 15 minutes.

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Notes from Session 2: Charles Darwin – Natural selection and the story of the Fall

By the 19th century people were coming to terms with the fact that the history of the earth went back far beyond human history. Finding fossils was leading to the idea that some animals and plants were around long before others and that some had become extinct.

But most people still believed that however it happened – living things were created as they are now. May be not over 6 days, but God made horses to appear – as horses, fish of different types to appear etc. There were obviously living things that had existed but were now extinct, but the theory was that as one species became extinct another one somehow appeared to take its place. Most importantly they believed that God made humans as they are now – vitally different to all other living things – in ways we talked about last week. ‘In the image of God’ – whether we think of that as ideas, being able to have a relationship with God, being able to imagine, to worship – was something unique to humans.

This was challenged by a scientific bombshell – arrived at by a couple of people – but attributed mainly to Charles Darwin.

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Notes from Session 1: James Hutton, Genesis 1-2

We are probably all familiar with the two creation stories in Genesis. And we also know that they can’t be literally true.

Give them to a class of 10 year olds and they will ask

  • If no one was there – how do we know what God said?
  • How did God make light on the first day – when he didn’t make the sun til the fourth?
  • Which of the two accounts is actually true?

Most people now accept that Genesis was never intended as a factual account – but go back 300 years and this was less true.

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Introduction to the Course

In this Lent course – apart form having the chance to get excited about science again – I am hoping that we can see how faith has been challenged by science – but also enriched by it, as we are forced to look again at how we understand our faith and particularly the bible.

For me, this means accepting that both science and faith are trying to find out the truth, and that both do this by suggesting ideas and theories which are tested against observations, experiences, experiments. The models – scientific or theological are not the truth – they are the nearest we can get to the truth at the moment.

I would just like to say that the way we understand scientific truth, and scientific writing – which is very literal – is quite a modern idea – 3-400 years old. Before that – right back to the writers of the bible – people used story, metaphor, allegory to edge towards the truth.

I offer these evenings not so much for us to debate whether we should read the bible literally or not. For me – we are freed from that attempt by the science I am sharing. I hope we might look instead for truths we recognise in these bible passages – because they chime with our experiences.

I would like to share some words of Alan Bennett – written about reading in general – but I think very apt.

“The best moments in reading are when you come across something – a thought, a feeling, a way of looking at things – that you’d thought special, particular to you. And here it is, set down by someone else, a person you’ve never met, maybe even someone long dead. And it’s as if a hand has come out and taken yours.”