About The Universe 1: Introduction
Disclaimer: I am an expert neither on science nor religion. I have tried my best to ensure everything written herein is accurate, but if you spot a factual mistake, please post any suggested corrections in the comments section below and I will make the appropriate changes as soon as possible.
Some years ago, I had a young American girlfriend. One day, she told me she “didn’t believe in evolution” (evolution is the process by which plants and animals evolve over thousands or millions of years into more complicated or refined species). She said it as if evolution was something you could choose to believe in or not – like Santa Claus.
I was quite startled by this – it made me wonder what kids are being tought in schools in the U.S. these days – but, I should not have been so surprised. Nobody had ever bothered to explain evolution to her and she had no reason to ask: as a Christian with strong faith, for her, God created the Earth and put plants, animals and humans on it.
I am still friends with my ex-girlfriend and recently I approached her with renewed enthusiasm to try and give her meaningful answers about evolution and the general nature of physics and the universe, partly inspired by reading some books and other scientific material including an overdue re-read of Stephen Hawking’s A Brief History of Time. Brief History is meant to be a no-nonsense guide to modern physics for the layman, but in my personal opinion is still far too complicated for the person with no science background to understand. So I decided it would be interesting to publish a mini-guide of my own.
The target audience for these articles is:
- Normal people with no science or math background who want to understand the world around them better.
- People who don’t know anything about how the universe began or what evolution does, and aren’t interested in becoming rocket scientists to find out.
- Open-minded people of religious faith who want to find out how their current beliefs fit in with real-life observations about what is happening around us, and what has happened in the observable past.
I particularly want to address this last group of people first, and set their minds at ease.
Science is not competing with religion
A main aim of modern science is to create models which help us understand how things work. Science does not seek to disprove the beliefs held by different religious sects, science is in fact completely indifferent to the happenings in the religious world. It just so happens that sometimes models are found to agree with real-world observation, which also conflict with the views held by some religious groups. Since the scientific models have been verified with real-world observation, and the religious models have not, the religious models are forced to be redefined to take new scientific data into account. This is often perceived as incompatibility between religion and science.
Science and religion are fully compatible with each other – one does not have to “choose” between one or the other. However, what does happen is that science narrows the power and scope of omnipotent beings like God. The ways and timeframes in which God can intervene in events in our universe are limited by scientific laws which we know to be extremely accurate, and with which few people would argue (for example, God never intervenes in the force of gravity, and in fact he can’t do so without creating an energy imbalance in the universe – I’ll explain this in more detail later).
The Vatican Church acknowledges the complimentary nature of religion and science. Until recently they held the view that the Sun rotated around the Earth. This was shown by direct observation not to be the case (the Earth rotates around the Sun). After that, the Vatican Church invited a number of leading scientists to help advise it on subjects such as the big bang (the big bang is a theory about how the universe began), and they revised their interpretation of Creation to reflect current scientific thinking.
Science can verify its discoveries, but it cannot prove them definitively
Science works by using real-world observations to create models of how our world works. For example, we have noticed that if you heat water above 100C, it turns into steam and boils away. If we cool it below 0C, it freezes and turns into ice. We tried heating and cooling other materials, like mercury (the stuff used in thermometers) and nitrogen (used as a cooling agent to keep things like human organs extremely cold and preserved during transportation), and discovered they boil away and freeze at certain specific temperatures too (Mercury boils at 357C and freezes at -39C; Nitrogen boils at -196C and freezes at -210C).
Will water, mercury and nitrogen always behave in this way? Science can’t prove that. All we can do is observe the materials in the real world, see how they behave, and run experiments when possible to test our ideas. Each time we observe that the behaviour of water matches our model of boiling at 100C and freezing at 0C, we can become more confident that our model is in fact a correct, accurate representation of the world. But what science can’t do, is guarantee that water will always boil at 100C and always freeze at 0C. If, just one time, water didn’t boil or freeze when it was supposed to, the scientific model would be disproven – it would shown to not be true all of the time, and therefore, it must be incorrect or incomplete.
So if science can’t prove anything, how can we trust anything it tells us? Well, some scientific models have more credence than others. I’m pretty sure you know that if you let go of your coffee cup, it will fall to the floor. Even the hardcore anti-scientist would likely not dispute that. Such is the reputation of certain scientific models. Gravity has been observed in action trillions of times by billions of people, and it has never been shown to disagree with our model of gravity or predictions on how gravity will affect one object as it is attracted towards another. So, we can trust with a very high degree of confidence – based on those trillions of observations – that our model of gravity is correct. There are many other scientific models in which we can place a similar level of confidence, but as always in the field of discovery, the newest proposed models are the ones in which we can be least confident. I will prefer to discuss only models we know to be accurate across many observations in these articles.
Religious texts are not literal documents
Most Christians and followers of other religions understand that texts such as the Bible should not be taken literally – that is, they are metaphorical (that means they describe real-world events using simplified analogies). In particular, in the book of Genesis, most people know that Adam and Eve is a metaphorical tale of evolution, and that the story of the 6 days of creation and one day of rest is a compressed timeline which just gives a brief overview of how the universe was created.
In case you believe these stories as they are written, consider some real-world observations we have made:
- In order for humans to exist, we require a heat source (the Sun, which is a star). Using observations made with telescopes, we can easily see that 6 days is insufficient time for the Sun and Earth to form, the atmosphere to stabilise with the oxygen we need to breathe, and for humans to evolve from the single-celled organisms from which life began. In fact we know that the Sun is a 2nd or 3rd generation star, because it contains trace elements of chemicals found in the explosions of other stars that have long since disappeared (stars exist by burning fuel and tend to become unstable and explode when the fuel runs out). Again using telescopes, we have observed that it takes hundreds or thousands of millions of years for a star to burn out, so at least that long must have passed before the Sun and Earth were created (I will explain how we can work this out from only a few years’ observations later).
- The atmosphere of the Earth when it was formed was such that the planet would have been inhospitable by humans. We know this because we can slice apart rocks – which slowly emit gas into the atmosphere over long periods of time – and look at their composition in the same way you can look at a cross-section of a tree log to find out how old it is. Examining old rocks in this way tells us that our atmosphere used to contain almost entirely nitrogen and very little oxygen, which we need to survive. We now know that life initially started in the sea, and the plants and organisms which thrived released oxygen (in the same way we release carbon dioxide when we exhale). Over a very long time this turned the balance of the atmosphere just enough to give us the amount of oxygen we need to survive today (the atmosphere consists of about 80% nitrogen and 20% oxygen today, with trace elements of argon and other substances). Humans could not have survived on Earth before the atmosphere reached this balance.
- DNA is a very complex substance common to all organisms which determines how they will develop and grow, and what characteristics and behaviours they will have. DNA is passed from parent(s) to child such that the child will have the same characteristics of the parent(s). Evolution occurs when the DNA is replicated to the child during conception, and an error occurs, causing the child’s DNA to be slightly different. I will discuss this in more detail later, but right now, consider that humans share 98% of their DNA with chimpanzees, 95% with dogs, 50% with fireflies and 33% with daffodils. This is overwhelming evidence that daffodils, fireflies, dogs, chimpanzees and humans weren’t all put on the Earth at the same time, but that each lifeform developed in turn from the previous ones. We have been able to measure the rate of evolution and know that it is extremely slow – it takes millions of years to get from a daffodil to a human.
- Snakes don’t talk. They don’t have vocal chords. This should be a strong clue to most people that the story of Adam and Eve is intended to be taken metaphorically.
Omnipotent beings don’t exist
Omnipotent beings are beings that can do literally anything. God is usually ascribed as an omnipotent being.
Consider this question:
Can God create a stone so heavy he can’t lift it?
Let’s look at the possible answers.
- Yes, he can create a stone so heavy he can’t lift it. In that case, God cannot be omnipotent as he is unable to lift the stone he has created.
- God can lift any stone of any weight. In that case, God cannot be omnipotent as he is unable to create a stone that he can’t lift, since he can lift anything.
This simple truth rules out the possibility of an omnipotent being existing. But don’t despair – God doesn’t have to be omnipotent to be useful, or play an important role in your beliefs. It is important to understand though, that omnipotency is not possible.
Science and religion are not mutually exclusive, but science reshapes the role of religion as new discoveries are made.
My ex-girlfriend made the good point that scientists ignore one important aspect of religion: faith. That is absolutely true. The reason scientists aren’t interested in faith is because their discoveries and beliefs are based on real-world observations, so it is not necessary to have faith in order to accept them. Scientific models are frequently scrutinised and reviewed, and models that are found to be incorrect are discarded or altered to fit the observations we’ve made. Science describes the world in terms of models and numbers that only have one possible interpretation, so there is no room for misunderstanding when comparing the models with our observations.
On the other hand, religious belief systems are based on religious texts and teachings, which are not updated regularly and are subject to changing interpretations as our environment and culture changes. Religious teachings cannot be disproven by observation like scientific models can, so they cannot be discarded or refined to more closely reflect reality either. The lack of observational evidence or the ability to prove or disprove one’s beliefs drives the need for faith when subscribing to a particular religion.
In the next section, I’ll talk a little about our home planet: Earth.
2nd April 2007: Thanks to phpnub for a correction regarding the nature of nitrogen in our atmosphere.
- Science and religion are complements – The MIT Tech (tech.mit.edu)
- On reconciling science and religion (tech.mit.edu)