“I don't feel frightened by not knowing things, by being lost in a mysterious universe without any purpose, which is the way it really is, as far as I can tell. Possibly. It doesn't frighten me.”
― Richard P. Feynman
So... are there things we can never know? Two areas worth exploring are physics and biology, in particular, the stuff the universe is made of, and the stuff we are made of.
The stuff the universe is made of
98% of the universe is invisible, 4% is made of atoms (and we've only seen half of that). 23% of the universe is dark matter which is invisible or gives out so little light we can't detect it. We know it's there because it pulls on the stars and the galaxies so we see them moving. But, the major mass component of the universe is dark energy which accounts for 73% of the mass-energy of the universe. Discovered in 1998, it's invisible, it fills all of space and it's speeding up the expansion of the universe. So after 350 years of science we are still only able to study 2% of the universe.
Dark energy is a profound puzzle, and its discovery was unexpected. The standard big bang model says the universe began in a hot dense state about 14 billion years ago and has been expanding and cooling ever since, with galaxies congealing out of this stuff. As galaxies fly apart they should slow down because of gravity – this is an obvious prediction. But in 1998 teams in America discovered that the galaxies are speeding up flying apart faster and faster so empty space seems to be filled with "springy" space stuff that is pushing the galaxies apart. And that's dark energy If we take quantum theory – the best description of reality we have – which explains why tables are solid and why the sun shines, which has given us lasers, nuclear reactors and computers – when we use quantum theory to calculate the energy of empty space (dark energy) we get a number that is 1 followed by 120 zeros bigger than we observe. The biggest discrepancy between a prediction and an observation in the history of science.
The stuff that we are made of
In biology the biggest question is, why are there so few genes? We have sequenced the entire human genome – we can read the entire DNA of a person in 15 minutes. But now we see there are remarkably few genes. A few decades ago we used to think there were millions of genes needed to make complex life forms. But there's only 24,000 to make a human being and that's less than you need to make a cabbage. It's about the same number of components that you need to make a London bus. So it can be argued that we don't really understand genetics. We are like someone with a whole collection of buckets containing all the components needed to make a bus and we don't know how. For biology in particular, it does seem that the more we know the less we understand.
Dark energy and dark matter can conceivably be solved, especially using equipment like the LHC but that's not true with genetics. It seemed to be clear and simple in the 1920s but we can see now how messy biology is.
Why does a cabbage have more genes than us? Maybe DNA is not the genetic material or maybe it's only part of it. DNA used to be called the "stupid molecule" as it was everywhere but didn't seem to do anything. Now DNA is iconic but maybe in the process of heredity, DNA is only be a small part of the process.
Science Is All About uncertainty
Science requires us to accept that we don't know everything - doubt is the very basis of science. We can define science in one word – pessimism. Scientists assume what they've found is wrong and then test it until they can see it might be right. The commonest phrases scientists use are “I don't know” and "I don't understand." From there they move on and find something so they know a bit more. The opposite position is to be certain about reality, and that's religion. And that's when you've abandoned all interest and curiosity in life.
Biology has problems with complexity rather than fundamental problems in physics Emergent properties occur in biology - the brain has neurones and synapses but actually it's much more than that - consciousness etc. emerge from that. So consciousness is hard to understand. To buy the chemicals to make a human being would cost about £25. But with those chemicals you'd never be able to make a human.
Epistemology
Epistemology is one of the core areas of philosophy. It is concerned with the nature, sources and limits of knowledge. But philosophy is to science as porn is to sex: cheaper, easier and some people prefer it. Biology seems much more complex than physics - or maybe physics is as complex as biology, but because physicists only look at the easy bits it seems simpler.
In ancient times people felt they knew more – but that's because there wasn't much they didn't know they didn't know. If you live in a world with three books and you've read them all, you know everything you can know. In the late 19th century many physicists thought everything had been solved - Kelvin said in 1900 that science was pretty much over and that was right on the eve of the quantum revolution, just before Max Planck discovered the quantum, and suddenly we realised everything we knew about physics was wrong.
"The greater the continent of knowledge, the longer the coastline of the unknown"
And so we keep finding out more things we don't know. But it means we can ask better and more precise questions, and phrase them better, and therefore have more chance of answering them .
Oscar Wilde said "I am no longer young enough to know everything."
The average 5 year old knows everything – or rather everything they need to know – but finding out you don't know anything is a marvellous moment in our education.
"The greater our knowledge increases the more our ignorance unfolds."
- John F. Kennedy
Taken from The Infinite Monkey Cage on BBC Radio 4. Contributors:
Marcus Chown (science writer, journalist and broadcaster, currently cosmology consultant for New Scientist magazine)
Professor Steve Jones (geneticist and Head of the Department of Genetics, Evolution and Environment at University College London)
― Richard P. Feynman
So... are there things we can never know? Two areas worth exploring are physics and biology, in particular, the stuff the universe is made of, and the stuff we are made of.
The stuff the universe is made of
98% of the universe is invisible, 4% is made of atoms (and we've only seen half of that). 23% of the universe is dark matter which is invisible or gives out so little light we can't detect it. We know it's there because it pulls on the stars and the galaxies so we see them moving. But, the major mass component of the universe is dark energy which accounts for 73% of the mass-energy of the universe. Discovered in 1998, it's invisible, it fills all of space and it's speeding up the expansion of the universe. So after 350 years of science we are still only able to study 2% of the universe.
Dark energy is a profound puzzle, and its discovery was unexpected. The standard big bang model says the universe began in a hot dense state about 14 billion years ago and has been expanding and cooling ever since, with galaxies congealing out of this stuff. As galaxies fly apart they should slow down because of gravity – this is an obvious prediction. But in 1998 teams in America discovered that the galaxies are speeding up flying apart faster and faster so empty space seems to be filled with "springy" space stuff that is pushing the galaxies apart. And that's dark energy If we take quantum theory – the best description of reality we have – which explains why tables are solid and why the sun shines, which has given us lasers, nuclear reactors and computers – when we use quantum theory to calculate the energy of empty space (dark energy) we get a number that is 1 followed by 120 zeros bigger than we observe. The biggest discrepancy between a prediction and an observation in the history of science.
The stuff that we are made of
In biology the biggest question is, why are there so few genes? We have sequenced the entire human genome – we can read the entire DNA of a person in 15 minutes. But now we see there are remarkably few genes. A few decades ago we used to think there were millions of genes needed to make complex life forms. But there's only 24,000 to make a human being and that's less than you need to make a cabbage. It's about the same number of components that you need to make a London bus. So it can be argued that we don't really understand genetics. We are like someone with a whole collection of buckets containing all the components needed to make a bus and we don't know how. For biology in particular, it does seem that the more we know the less we understand.
Dark energy and dark matter can conceivably be solved, especially using equipment like the LHC but that's not true with genetics. It seemed to be clear and simple in the 1920s but we can see now how messy biology is.
Why does a cabbage have more genes than us? Maybe DNA is not the genetic material or maybe it's only part of it. DNA used to be called the "stupid molecule" as it was everywhere but didn't seem to do anything. Now DNA is iconic but maybe in the process of heredity, DNA is only be a small part of the process.
Science Is All About uncertainty
Science requires us to accept that we don't know everything - doubt is the very basis of science. We can define science in one word – pessimism. Scientists assume what they've found is wrong and then test it until they can see it might be right. The commonest phrases scientists use are “I don't know” and "I don't understand." From there they move on and find something so they know a bit more. The opposite position is to be certain about reality, and that's religion. And that's when you've abandoned all interest and curiosity in life.
Biology has problems with complexity rather than fundamental problems in physics Emergent properties occur in biology - the brain has neurones and synapses but actually it's much more than that - consciousness etc. emerge from that. So consciousness is hard to understand. To buy the chemicals to make a human being would cost about £25. But with those chemicals you'd never be able to make a human.
Epistemology
Epistemology is one of the core areas of philosophy. It is concerned with the nature, sources and limits of knowledge. But philosophy is to science as porn is to sex: cheaper, easier and some people prefer it. Biology seems much more complex than physics - or maybe physics is as complex as biology, but because physicists only look at the easy bits it seems simpler.
In ancient times people felt they knew more – but that's because there wasn't much they didn't know they didn't know. If you live in a world with three books and you've read them all, you know everything you can know. In the late 19th century many physicists thought everything had been solved - Kelvin said in 1900 that science was pretty much over and that was right on the eve of the quantum revolution, just before Max Planck discovered the quantum, and suddenly we realised everything we knew about physics was wrong.
"The greater the continent of knowledge, the longer the coastline of the unknown"
And so we keep finding out more things we don't know. But it means we can ask better and more precise questions, and phrase them better, and therefore have more chance of answering them .
Oscar Wilde said "I am no longer young enough to know everything."
The average 5 year old knows everything – or rather everything they need to know – but finding out you don't know anything is a marvellous moment in our education.
"The greater our knowledge increases the more our ignorance unfolds."
- John F. Kennedy
Taken from The Infinite Monkey Cage on BBC Radio 4. Contributors:
Marcus Chown (science writer, journalist and broadcaster, currently cosmology consultant for New Scientist magazine)
Professor Steve Jones (geneticist and Head of the Department of Genetics, Evolution and Environment at University College London)
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