All our facts will soon be wrong, scientist claims

Not to scale: Dinosaurs are now thought to have been feathered, like this Epidexipteryx (left).

We like to think of science as a way of getting at facts – but according to a new book by scientist Samuel Arbesman, even facts have an expiry date. The truth, it seems, keeps on shifting.

Education, it is widely agreed, is about facts. Every year, young people in schools spend hours learning as much information as they can – science formulae, historical dates, mathematical rules – in order to pass exams. It seems clear that a good commmand of facts is a vital preparation for life.

But now, a new book* by mathematician Samuel Arbesman has put forward a bold and unsettling theory. We think of facts as certain and eternal; solid foundations of truth on which to build a whole structure of knowledge. That picture is wrong, says Arbesman. Really, facts are not solid but shifting.

What’s more, if you look at the way facts shift, you can see it follows regular mathematical patterns. Arbesman looked at scientific papers in physics, for example, and found that physics facts appear to have what he calls a ‘half life‘ of around ten years: every ten years, half the facts in a physics paper simply go out of date.

Facts go out of date at different speeds depending on the field, but the overall effect is the same: by the time a person reaches middle age, much of what they learned at school will no longer be true.

Sometimes old facts turn out to have been wrong all along. It was only twenty years ago, for example, that children were taught that dinosaurs were cold-blooded reptiles covered in scales. Now we know that many dinosaurs were warm blooded and had brightly coloured feathers.

Other facts just change over time. The population of the Earth, for example, or the proportion of people who use mobile phones. Even something that looks fixed can change. Mount Everest, for example, gets a little bit taller every year – and no one is even sure how much.

Then there are facts that change because the entire theoretical framework that supports them starts to crumble. Schools still teach students the laws of Newtonian physics – which are excellent at predicting the behaviour of mechanical systems. But it has been more than a century since Einstein showed that Newton’s laws were false. The first lesson of many university physics courses? Forget everything you learnt at school and start again.

A matter of fact

If facts are so unreliable, what then are teachers meant to teach? Perhaps, say some, the aim of classes is not to acquire information but to gain new skills and have new experiences. Perhaps, in this age of Wikipedia and smartphones, it is less important to know the answers than to be able to ask the right questions.

But not everyone is convinced by this sort of fancy thinking. It’s simple, opponents say: School is for learning about the world. An education without facts is no education at all.

*The Half-Life of Facts: Why Everything We Know Has an Expiration Date, by Samuel Arbesman, published by Current in October 2012.

You Decide

  1. Is it possible have an education without any facts?
  2. Can you be sure that everything you believe is true is not, in fact, really just an illusion?


  1. Albert Einstein once said: ‘Education is what remains after one has forgotten what one has learnt in school.’ Write a short article explaining what you think he meant, and whether or not you agree.
  2. Write and deliver a short speech arguing (as convincingly as you can) that something everyone knows to be true is actually false. The more outlandish your claim is, the better.

Some People Say...

“The wisest man in the world is one who knows that he knows nothing.”

What do you think?

Q & A

I’m not worried. I know what I know.
Do you though? Do you never worry that you might be living in a super-advanced simulation, run by evil robots like inThe Matrix? That everything you think you know might be a lie?
This can’t be a simulation. I know the world is real because I can touch it and see it around me?
Think about it though – when you ‘see’ something, all that’s happening is that your brain is getting electrical signals from nerves connected to your eyes, which you assume are stimulated by light from the outside world. What if all the signals just came from an electrode attached to your optic nerve? How would you know the difference?
I suppose it might be hard to tell.
On the other hand, even if the world is a simulation, there might not be much point in worrying about it!

Word Watch

‘Formula’, like many words in English, is stolen from Latin. That means that when it goes into the plural, it does so like a Latin word (‘-a’ becomes ‘-ae’) rather than like an English word, by adding an ‘s’. The rules for Latin pluralisation are annoyingly complicated however. ‘-us’ (as in ‘radius’) goes to ‘-i’. ‘-um’ (as in ‘curriculum’) goes to ‘-a’. Meanwhile, ‘criteria’ and ‘phenomena’ are both Greek plurals that should, in the singular, end in ‘-on’. Understandably, many writers now chose to ignore these rules altogether.
Half life
The idea of a half life is most familiarly used when talking about radioactive decay. Radium 226, for example, an isotope of radioactive metal, has a halflife of 1601 years. That means that half of any given lump of radium 226 will decay in 1601 years. In another 1601 years, half the remainder will decay. In another 1601 years, half again. But the radium lump never decays entirely.
Newton’s laws
Isaac Newton discovered three principles that he thought governed the movement of all objects in the universe. An object in motion will maintain its course and speed if no force acts upon it; force is equal to mass times acceleration; every action has an equal and opposite reaction. These three laws work brilliantly to predict the motion of medium-sized objects. In the 20th Century, however, it was shown that when you deal with big objects like planets, or tiny objects like atoms, the laws begin to break down.


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