"The Magic of Reality" by Richard Dawkins

• Reality is everything that exists.
• Our five senses--sight, smell, touch, hearing and taste--do a pretty good job of convincing us that many things are real.
• Because we understand telescopes and microscopes, and how they work, we can use them to extend the reach of our senses.
• What we see when we look at anything is actually light, and light takes time to travel.
• Sound travels much more slowly, which is why you see a firework burst in the sky noticeably earlier than you hear the bang.
• Light travels so fast that we normally assume anything we see happens at the instant we see it.
• Even the sun is eight light-minutes away. If the sun blew up, this catastrophic event wouldn’t become a part of our reality until eight minutes later.
• Galaxies are huge collections of stars.
• For reality doesn’t just consist of things we already know about: it also includes things that exist but that we don’t know about yet and won’t know about until some future time, perhaps when we have built better instruments to assist our five senses.
• We should always be open-minded, but the only good reason to believe that something exists is if there is real evidence that it does.
• We come to know what is real in one of three ways. We can detect it directly, using our five senses; or indirectly, using our senses aided by special instruments such as telescopes and microscopes; or even more indirectly, by creating models of what might be real and then testing those models to see whether they successfully predict things that we can see (or hear, etc.), with or without the aid of instruments. Ultimately, it always comes back to our senses, one way or another.
• Supernatural magic is the kind of magic we find in myths and fairy tales.
• Stage magic, by contrast, really does happen, and it can be great fun. Or at least, something really happens, though it isn’t what the audience things it is. A man on a stage deceives us into thinking that something astonishing has happened (it may even seem supernatural) when what really happened was something quite different.
• The third meaning of magic is the one I mean in my title: poetic magic. In this sense, ‘magical’ simply means deeply moving, exhilarating: something that gives us goose bumps, something that makes us feel more fully alive.
• Indeed, to claim a supernatural explanation of something is not to explain it at all and, even worse, to rule out any possibility of its ever being explained.
• Science thrives on its inability--so far--to explain everything, and uses that as the spur to go on asking questions, creating possible models and testing them, so that we make our way, inch by inch, closer to the truth.
• The whole history of science shows us that things once thought to be the result of supernatural--caused by gods (both happy and angry), demons, witches, spirits, curses and spells--actually do have natural explanations that we can understand and test and have confidence in. There is absolutely no reason to believe that those things for which science does not yet have natural explanations will turn out to be of supernatural origin, any more than volcanoes or earthquakes or diseases turn out to be caused by angry deities, as people once believed they were.
• It is very difficult to make a complicated thing like a frog or a coach.
• The answer is that complex organisms--like humans, crocodiles and Brussels sprouts--did not come about suddenly, in one fell swoop, but gradually, step by tiny step, so that what was there after each step was only a little bit different from what was already there before.
• Darwin was the first person to understand that it [selective breeding] works even when there is no breeder to do the choosing. Darwin saw that the whole thing would happen naturally, as a matter of course, for the simple reason that some individuals survive long enough to breed and others don’t; and those that survive do so because they are better equipped than others. So the survivors’ children inherit the genes that helped their parents to survive.
• The number of generations required [for speciation] is larger than you or I can possibly imagine, but the world is thousands of millions of years old, and we know from fossils that life got started more than three and a half billion years ago, so there has been plenty of time for evolution to happen.
• Evolution is a real explanation, which really works, and has real evidence to demonstrate the truth of it; anything that suggests that complicated life forms appeared suddenly, in one go (rather than evolving gradually step by step), is just a lazy story--no better than the fictional magic of a fairy godmother’s wand.
• All peoples around the world have origin myths, to account for where they came from.
• Indeed, most of the gods of history were portrayed as men (or sometimes women), often of giant size and always with supernatural powers.
• The Norse peoples of Scandinavia, famous as Viking seafarers, had lots of gods, as the Greeks and Romans did. The name of their chief god was Odin, sometimes called Wotan or Woden, from which we get our ‘Wednesday’. (‘Thursday’ comes from another Norse god, Thor, the god of thunder, which he made with his mighty hammer.)
• This may surprise you, but there never was a first person--because every person had to have parents, and those parents had to be people too!
• Every creature ever born belonged to the same species as its parents (with perhaps a very small number of exceptions, which I shall ignore here).
• Believe it or not, your 185-million-greats-grandfather was--a fish.
• At some point, probably less than a million years ago but more than a hundred thousand years ago, our ancestors were sufficiently different from us that a modern person wouldn’t have been able to breed with them if they had met.
• Fossils are made of stone. They are stones that have picked up the shapes of dead animals or plants. The great majority of animals die with no hope of turning into a fossil. The trick, if you want to be a fossil, is to get yourself buried in the right kind of mud or silt, the kind that might eventually harden to form ‘sedimentary rock’.
• Fossils can even be dated. We can tell how old they are, mostly by measuring radioactive isotopes in the rocks.
• DNA is the genetic information that all living creatures carry in each of their cells. The DNA is spelled out along massively coiled ‘tapes’ of data, called ‘chromosomes’.
• Counting the number of letter differences in such genes is useful for working out how closely related different mammal species are.
• What is a fact beyond all doubt is that we share an ancestor with every other species of animal and plant on the planet. We know this because some genes are recognizably the same genes in all living creatures, including animals, plants and bacteria. And, above all, the genetic code itself--the dictionary by which all genes are translated--is the same across all living creatures that have ever been looked at.
• Adam’s task of naming all the animals was a tough one--tougher than the ancient Hebrews could possibly have realized. It’s been estimated that about 2 million species have so far been given scientific names, and even these are just a small fraction of the number of species yet to be named.
• Animals belong to different species if they don’t breed together.
• Every scientific name of an animal or plant consists of two Latin words, usually printed in italics. The first word refers to the ‘genus’ or group of species and the second to the individual species within the genus.
• Every species is a member of a genus.
• Each genus belongs to a family, usually printed in ordinary ‘roman’ type with a capital initial.
• Every family belongs to an order.
• When two ways of speaking a language have drifted sufficiently far apart, we call them different ‘dialects’.
• After enough centuries of drift, different regional dialects eventually become so different that people in one region can no longer understand people in another. At this point we call them separate languages.
• When individuals reproduce sexually, they mix their DNA.
• The Galapagos islands are historically important because they probably inspired Charles Darwin’s first thoughts on evolution when, as a member of the expedition on HMS beagle, he visited them in 1835.
• The Greek for ‘cut’ is tomos, and if you stick an ‘a’ in front of a Greek word it means ‘not’ or ‘you can’t’. So ‘a-tomic’ means something too small to be cut any smaller, and that is where our word ‘atom’ comes from.
• We now know that there are about 100 different kinds of atoms, of which only about 99 percent occur in nature.
• Pure substances that consist of one kind of atom only are called elements.
• But most of the substances that we see around us are not elements but compounds. A compound is what you get when two or more different atoms join together in a particular way.
• A group of atoms joined together to make a compound is called a molecule.
• Solid, liquid and gas are the names we give to the three common ‘phases’ of matter.
• A scientific model is a way of thinking about how things might be.
• A successful model is one whose predictions come out right, especially if they survive the test of experiment.
• The main difference between a proton and a neutron is that the proton has an electric charge. Electrons, too, have an electric charge, opposite to that of protons.
• For every possible number from 1 to 100 (and a few more), there is one and only one element that has that number of protons (and the same number of electrons).
• The number of protons (or electrons) that an element possesses is called the ‘atomic number’ of that element.
• The number of neutrons in an atom’s nucleus is less fixed than the number of protons: many elements have different versions, called isotopes, with different numbers of neutrons.
• The whole world is made of incredibly tiny things, much too small to be visible to the naked eye--and yet none of the myths or so-called holy books that some people, even now, think were given to us by an all-knowing god, mentions them at all!
• In fact, unsurprisingly, the stories in holy books don’t contain any more information about the world than was known to the primitive peoples who first started telling them!
• The aboriginal peoples of Australia were isolated on their island continent for at least 40,000 years, and they have some of the oldest myths in the world. These are mostly set in a mysterious age called the Dreamtime, when the world began and was peopled by animals and a race of giant ancestors.
• Many myths and legends from all around the world have the same odd feature: a particular incident happens once, and then, for reasons never explained, the same thing goes on happening again and again for ever.
• Wherever things change rhythmically with great precision, scientists suspect that either something is swinging like a pendulum or something is rotating: going round and round.
• The illusion that the sun moves across the sky is just that--an illusion. It’s the illusion of relative movement.
• When an object, such as a space station, is in orbit, it is ‘falling’ the whole time, and all the objects in the space station, whether we think of them as light or heavy, are falling at the same rate.
• Weight is the pull of gravity on your mass.
• The Earth’s orbit around the sun is technically an ellipse, but it is very nearly the special case of a circle.
• Sun worship often goes together with moon worship, and the sun and the moon are frequently regarded as being of opposite sex.
• The sun is a star. It’s no different from lots of other stars, except that we happen to be near it so it looks much bigger and brighter than the others.
• The larger any object is, the stronger the gravitational pull towards its centre. Everything pulls everything by gravity.
• The sun will become a red giant in about five billion years’ time, which means it is pretty much in the middle of its life cycle at the moment.
• Only about 20 supernovas have been seen in recorded history.
• Without occasional (but very rare) supernova explosions, the elements necessary for life would not exist.
• The whole solar system, which means the sun and the planets, began as a slowly spinning cloud of gas and dust, probably the leftovers of a supernova explosion.
• Scientists now have evidence that an even larger meteor hit Yucatan, in what is now Central America, 65 million years ago, causing a global disaster, which is probably what killed off the dinosaurs.
• Why does life have to be close to a star? Because all life needs energy, and the obvious source of energy is starlight.
• It is obvious that the Jewish story of Noah is nothing more than a retelling of the older legend of Utnapishtim.
• Newton discovered that white light is really a mixture of all the different colours.
• When a beam of light travels through air and hits glass, it gets bent. The bending is called refraction. Refraction doesn’t have to be caused by glass: water does the trick too, and that will be important when we come back to the rainbow.
• The angle at which light bends is slightly different depending on what colour the light is.
• Light can be thought of as vibrations: waves. Just as sound is vibrations in the air, light consists of what are called electromagnetic vibrations.
• There are sounds that are too high-pitched for us to hear. They are called ultrasound; bats can hear them and use the echoes for finding their way around. There are also sounds that are too low for us to hear. They are called infrasound; elephants, whales and some other animals use these deep rumbles for keeping touch with each other.
• What is a bit surprising is that the light we humans can actually see-the spectrum or ‘rainbow’ of visible colours between the slightly ‘higher-pitched’ violet and the slightly ‘lower-pitched’ red--is a very tiny band in the middle of a huge spectrum ranging from gamma rays at the high-pitched end to radio waves at the low-pitched end. Almost the whole of the spectrum is invisible to our eyes.
• What I find a little disappointing about all these origin myths is that they begin by assuming the existence of some kind of living creature before the universe itself came into being.
• None of the myths gives any explanation for how the creator of the universe himself (and it usually is a he) came into existence.
• The big bang model, on the other hand, suggested that the universe began at a definite moment in time, in a strange kind of explosion. The predictions made on the basis of the big bang model keep turning out to be right, and so it has now been generally accepted by most scientists.
• According to the modern version of the big bang model, the entire observable universe exploded into existence between 13 and 14 billion years ago.
• The ‘observable universe’ means everything for which we have any evidence at all. It is possible that there are other universes that are inaccessible to all our senses and instruments.
• A spectroscope is a rainbow machine. If it is attached to a telescope, it takes the light from one particular star or galaxy and spread it out as a spectrum, just as Newton did with his prism.
• The colours we see inside our heads are really just labels made up by the brain to identify light of different wavelengths.
• If you are wondering what makes a cap, or a bus, red in the first place, the answer is that the molecules of dye, or paint, absorb most of the light of all colours except red. So in white light, which contains all wavelengths, mostly red light is reflected.
• The more distant the galaxy, the greater the shift towards the red.
• The shift of the spectrum towards the red end shows that very distant galaxies are travelling away from us at a rate of hundreds of millions of miles per hour.
• Today’s ‘models’ of the universe assume that it wasn’t only the universe that began with the big bang: time itself and space itself began with the big bang too.
• There is good evidence that some of our most vivid memories are actually false memories. And false memories can be deliberately planted by unscrupulous ‘therapists’.
• The point is that the images people see when experiencing sleep paralysis are not really there but are conjured up in the mind from past fears, legends or fiction.
• One of the effects of sleep paralysis is that, if you try to move, it feels as though something is pressing down on your body.
• One of the great virtues of science is that scientists know when they don’t know the answer to something.
• In our galaxy, the great majority of stars where we have looked for planets have turned out to posses them. So, assuming our galaxy is typical, we can probably conclude that most of the stars in the universe have planets in orbit around them.
• For life as we know it to exist, at least some of the water has to be in liquid form.
• Evidence suggests that water is not particularly rare on extrasolar planets.
• Any planet that has life is pretty much bound to be in the vicinity of a star, because a star is the most obvious source of the energy that all life needs. So the chances are good that light will be available wherever life is present; and where light is present it is very likely that eyes will evolve because they are so useful.
• In an earthquake, the whole landscape behaves like a sort of liquid. It looks like the sea, with waves passing through it. Solid, dry land, with waves sweeping through it as they do on the sea! That’s an earthquake.
• The modern theory of plate tectonics sees the whole crust of the Earth, including the bottom of the sea, as a complete set of interlocking plates.
• Sometimes a moving plate slides underneath a neighbouring plate. This is called ‘subduction’.
• Bad things do happen, and they happen to good people as well as bad.
• Everything does happen for a reason--which is to say that events have causes, and the cause always comes before the event.
• The universe has no mind, no feelings and no personality, so it doesn’t do things in order to either hurt or please you. Bad things happen because things happen. Whether they are bad or good from our point of view doesn’t influence how likely it is that they will happen. Some people find it hard to accept this.
• Natural selection, the struggle for existence as Darwin called it, means that every living creature has enemies that are working hard for its downfall.
• A cancer is a group of our own cells that have broken away from doing what they are supposed to do in the body and have become parasitic. Cancer cells are usually grouped together in a ‘tumour’, which grows out of control, feeding on some part of the body. The worst cancers then spread to other parts of the body (that’s called metastasis) and eventually often kill it. Tumours that do this are called malignant.
• Usually when we hear a miracle story it’s not from an eyewitness, but from somebody who heard about it from somebody else, who heard about it from somebody else, who heard about it from somebody else’s wife’s friend’s cousin… and any story, passed on by enough people, gets garbled. The original source of the story is often itself a rumour that began so long ago and has become so distorted in the retelling that it is almost impossible to guess what actual event--if any--started it off.
• Humans are social animals, the human brain is pre-programmed to see the faces of other humans even where there aren’t any. This is why people so often see faces in the random patterns made by clouds, or on slices of toast, or in damp patches on walls.
• If a rumour of a miracle gets written down in a book, the rumour becomes hard to challenge, especially if the book is ancient. If a rumour is old enough, it starts to be called a ‘tradition’ instead, and then people believe it all the more.
• The key point is that we only bother to tell stories when strange coincidences happen--not when they don’t.
• For a coincidence to be reported in a newspaper, it only has to be experienced by one person among the millions of readers who might write to the paper.
• People enjoy a good story so much that they embellish it to make it a bit better than it was when they heard it.
• If John tells you a miracle story, you should believe it only if it would be even more of a miracle for it to be a lie (or a mistake, or an illusion).
• All four of the gospels, by the way, were written long after the events that they purport to describe, and not one of them by an eyewitness.
• Any sufficiently advanced technology is indistinguishable from magic.
• The more you think about it, the more you realize that the very idea of a supernatural miracle is nonsense. If something happens that appears to be inexplicable by science, you can safely conclude on of two things. Either it didn’t really happen (the observer was mistake, or was lying, or was tricked); or we have exposed a shortcoming in present-day science.