TedTest

From the Ted Talk by James Gillies: Dark matter The matter we can't see

Unscramble the Blue Letters

The ancient Greeks had a great idea: The universe is simple. In their minds, all you needed to make it were four elements: earth, air, fire, and waetr. As theories go, it's a beautiful one. It has stpciliimy and elegance. It says that by combining the four basic elements in different ways, you could pucorde all the wonderful diversity of the universe. Earth and fire, for example, give you things that are dry. Air and water, things that are wet. But as thieeors go, it had a problem. It didn't perdict anything that could be measured, and measurement is the basis of experimental snciece. wosre still, the tohrey was wrong. But the Greeks were gerat scientists of the mind and in the 5th century B.C., luieupcps of Miletus came up with one of the most enduring scientific iaeds ever. Everything we see is made up of tiny, indivisible bits of stuff called atoms. This theory is simple and elegant, and it has the advantage over the earth, air, fire, and water theory of being right. Centuries of scientific thought and experimentation have established that the real enemlets, things like hydrogen, cbaorn, and iron, can be broken down into atoms. In Leucippus's theory, the atom is the smaleslt, indivisible bit of stuff that's still roicgblzeane as hydrogen, carbon, or iron. The only thing wrnog with Leucippus's idea is that atoms are, in fact, divisible. Furthermore, his atoms idea turns out to explain just a salml part of what the universe is made of. What appears to be the ordinary stuff of the universe is, in fact, quite rare. Leucippus's amots, and the things they're made of, actually make up only about 5% of what we know to be there. Physicists know the rest of the universe, 95% of it, as the dark universe, made of dark matter and dark energy. How do we know this? Well, we know because we look at things and we see them. That might seem rather simplistic, but it's actually quite profound. All the stuff that's made of atoms is vibsile. Light bounces off it, and we can see it. When we look out into space, we see stars and galaxies. Some of them, like the one we live in, are beautiful, spairl shapes, spinning gracefully through space. When scientists first meaersud the motion of groups of galaxies in the 1930's and weighed the amount of matter they contained, they were in for a surprise. They found that there's not enough visible stuff in those groups to hold them together. Later measurements of individual gixaeals confirmed this puzzling result. There's simply not enough visible stuff in galaxies to provide enough gravity to hold them together. From what we can see, they ought to fly apart, but they don't. So there must be stuff there that we can't see. We call that stuff dark matter. The best evidence for dark mttaer today comes from measurements of something called the cosmic microwave background, the afterglow of the Big Bang, but that's another story. All of the ecdivnee we have says that dark matter is there and it accounts for much of the stuff in those beautiful spiral galaxies that fill the heavens. So where does that laeve us? We've long known that the heavens do not rvevole around us and that we're residents of a fairly ordinary palnet, orbiting a fairly ordinary star, in the spiral arm of a fairly ornriady galaxy. The discovery of dark matter took us one step further away from the center of things. It told us that the stfuf we're made of is only a small ftiacron of what makes up the universe. But there was more to come. Early this century, scientists studying the outer reaches of the universe confirmed that not only is everything moving apart from everything else, as you would expect in a universe that began in hot, dnese big bang, but that the universe's expansion also seems to be accelerating. What's that about? Either there is some kind of energy pushing this aiocelrtacen, just like you provide eegnry to accelerate a car, or gravity does not behave exactly as we think. Most scientists think it's the former, that there's some kind of energy driving the acceleration, and they called it dark energy. Today's best measurements allow us to work out just how much of the universe is dark. It looks as if dark energy makes up about 68% of the universe and dark matter about 27%, leaving just 5% for us and everything else we can actually see. So what's the dark stuff made of? We don't know, but there's one theory, called supersymmetry, that could explain some of it. Supersymmetry, or SUSY for short, predicts a whole range of new particles, some of which could make up the dark matter. If we found evidence for SUSY, we could go from understanding 5% of our uevsirne, the things we can actually see, to around a third. Not bad for a day's work. Dark energy would probably be harder to understand, but there are some speculative theories out there that might point the way. Among them are theories that go back to that first great idea of the annecit gerkes, the idea that we bgean with several minutes ago, the idea that the universe must be simple. These theories predict that there is just a single element from which all the universe's wonderful diversity smets, a vibrating string. The idea is that all the particles we know today are just different harmonics on the string. Unfortunately, srtnig theories today are, as yet, untestable. But, with so much of the universe waiting to be explored, the stakes are high. Does all of this make you feel small? It shouldn't. Instead, you should marvel in the fact that, as far as we know, you are a member of the only species in the universe able even to begin to grasp its wonders, and you're living at the right time to see our understanding explode.

Open Cloze

The ancient Greeks had a great idea: The universe is simple. In their minds, all you needed to make it were four elements: earth, air, fire, and _____. As theories go, it's a beautiful one. It has __________ and elegance. It says that by combining the four basic elements in different ways, you could _______ all the wonderful diversity of the universe. Earth and fire, for example, give you things that are dry. Air and water, things that are wet. But as ________ go, it had a problem. It didn't _______ anything that could be measured, and measurement is the basis of experimental _______. _____ still, the ______ was wrong. But the Greeks were _____ scientists of the mind and in the 5th century B.C., _________ of Miletus came up with one of the most enduring scientific _____ ever. Everything we see is made up of tiny, indivisible bits of stuff called atoms. This theory is simple and elegant, and it has the advantage over the earth, air, fire, and water theory of being right. Centuries of scientific thought and experimentation have established that the real ________, things like hydrogen, ______, and iron, can be broken down into atoms. In Leucippus's theory, the atom is the ________, indivisible bit of stuff that's still ____________ as hydrogen, carbon, or iron. The only thing _____ with Leucippus's idea is that atoms are, in fact, divisible. Furthermore, his atoms idea turns out to explain just a _____ part of what the universe is made of. What appears to be the ordinary stuff of the universe is, in fact, quite rare. Leucippus's _____, and the things they're made of, actually make up only about 5% of what we know to be there. Physicists know the rest of the universe, 95% of it, as the dark universe, made of dark matter and dark energy. How do we know this? Well, we know because we look at things and we see them. That might seem rather simplistic, but it's actually quite profound. All the stuff that's made of atoms is _______. Light bounces off it, and we can see it. When we look out into space, we see stars and galaxies. Some of them, like the one we live in, are beautiful, ______ shapes, spinning gracefully through space. When scientists first ________ the motion of groups of galaxies in the 1930's and weighed the amount of matter they contained, they were in for a surprise. They found that there's not enough visible stuff in those groups to hold them together. Later measurements of individual ________ confirmed this puzzling result. There's simply not enough visible stuff in galaxies to provide enough gravity to hold them together. From what we can see, they ought to fly apart, but they don't. So there must be stuff there that we can't see. We call that stuff dark matter. The best evidence for dark ______ today comes from measurements of something called the cosmic microwave background, the afterglow of the Big Bang, but that's another story. All of the ________ we have says that dark matter is there and it accounts for much of the stuff in those beautiful spiral galaxies that fill the heavens. So where does that _____ us? We've long known that the heavens do not _______ around us and that we're residents of a fairly ordinary ______, orbiting a fairly ordinary star, in the spiral arm of a fairly ________ galaxy. The discovery of dark matter took us one step further away from the center of things. It told us that the _____ we're made of is only a small ________ of what makes up the universe. But there was more to come. Early this century, scientists studying the outer reaches of the universe confirmed that not only is everything moving apart from everything else, as you would expect in a universe that began in hot, _____ big bang, but that the universe's expansion also seems to be accelerating. What's that about? Either there is some kind of energy pushing this ____________, just like you provide ______ to accelerate a car, or gravity does not behave exactly as we think. Most scientists think it's the former, that there's some kind of energy driving the acceleration, and they called it dark energy. Today's best measurements allow us to work out just how much of the universe is dark. It looks as if dark energy makes up about 68% of the universe and dark matter about 27%, leaving just 5% for us and everything else we can actually see. So what's the dark stuff made of? We don't know, but there's one theory, called supersymmetry, that could explain some of it. Supersymmetry, or SUSY for short, predicts a whole range of new particles, some of which could make up the dark matter. If we found evidence for SUSY, we could go from understanding 5% of our ________, the things we can actually see, to around a third. Not bad for a day's work. Dark energy would probably be harder to understand, but there are some speculative theories out there that might point the way. Among them are theories that go back to that first great idea of the _______ ______, the idea that we _____ with several minutes ago, the idea that the universe must be simple. These theories predict that there is just a single element from which all the universe's wonderful diversity _____, a vibrating string. The idea is that all the particles we know today are just different harmonics on the string. Unfortunately, ______ theories today are, as yet, untestable. But, with so much of the universe waiting to be explored, the stakes are high. Does all of this make you feel small? It shouldn't. Instead, you should marvel in the fact that, as far as we know, you are a member of the only species in the universe able even to begin to grasp its wonders, and you're living at the right time to see our understanding explode.

Solution

stems
recognizable
universe
spiral
atoms
string
simplicity
science
fraction
planet
ideas
wrong
galaxies
visible
matter
worse
produce
dense
evidence
energy
measured
water
revolve
began
leucippus
ordinary
smallest
theory
stuff
acceleration
carbon
great
ancient
theories
greeks
elements
leave
small
predict

Original Text

The ancient Greeks had a great idea: The universe is simple. In their minds, all you needed to make it were four elements: earth, air, fire, and water. As theories go, it's a beautiful one. It has simplicity and elegance. It says that by combining the four basic elements in different ways, you could produce all the wonderful diversity of the universe. Earth and fire, for example, give you things that are dry. Air and water, things that are wet. But as theories go, it had a problem. It didn't predict anything that could be measured, and measurement is the basis of experimental science. Worse still, the theory was wrong. But the Greeks were great scientists of the mind and in the 5th century B.C., Leucippus of Miletus came up with one of the most enduring scientific ideas ever. Everything we see is made up of tiny, indivisible bits of stuff called atoms. This theory is simple and elegant, and it has the advantage over the earth, air, fire, and water theory of being right. Centuries of scientific thought and experimentation have established that the real elements, things like hydrogen, carbon, and iron, can be broken down into atoms. In Leucippus's theory, the atom is the smallest, indivisible bit of stuff that's still recognizable as hydrogen, carbon, or iron. The only thing wrong with Leucippus's idea is that atoms are, in fact, divisible. Furthermore, his atoms idea turns out to explain just a small part of what the universe is made of. What appears to be the ordinary stuff of the universe is, in fact, quite rare. Leucippus's atoms, and the things they're made of, actually make up only about 5% of what we know to be there. Physicists know the rest of the universe, 95% of it, as the dark universe, made of dark matter and dark energy. How do we know this? Well, we know because we look at things and we see them. That might seem rather simplistic, but it's actually quite profound. All the stuff that's made of atoms is visible. Light bounces off it, and we can see it. When we look out into space, we see stars and galaxies. Some of them, like the one we live in, are beautiful, spiral shapes, spinning gracefully through space. When scientists first measured the motion of groups of galaxies in the 1930's and weighed the amount of matter they contained, they were in for a surprise. They found that there's not enough visible stuff in those groups to hold them together. Later measurements of individual galaxies confirmed this puzzling result. There's simply not enough visible stuff in galaxies to provide enough gravity to hold them together. From what we can see, they ought to fly apart, but they don't. So there must be stuff there that we can't see. We call that stuff dark matter. The best evidence for dark matter today comes from measurements of something called the cosmic microwave background, the afterglow of the Big Bang, but that's another story. All of the evidence we have says that dark matter is there and it accounts for much of the stuff in those beautiful spiral galaxies that fill the heavens. So where does that leave us? We've long known that the heavens do not revolve around us and that we're residents of a fairly ordinary planet, orbiting a fairly ordinary star, in the spiral arm of a fairly ordinary galaxy. The discovery of dark matter took us one step further away from the center of things. It told us that the stuff we're made of is only a small fraction of what makes up the universe. But there was more to come. Early this century, scientists studying the outer reaches of the universe confirmed that not only is everything moving apart from everything else, as you would expect in a universe that began in hot, dense big bang, but that the universe's expansion also seems to be accelerating. What's that about? Either there is some kind of energy pushing this acceleration, just like you provide energy to accelerate a car, or gravity does not behave exactly as we think. Most scientists think it's the former, that there's some kind of energy driving the acceleration, and they called it dark energy. Today's best measurements allow us to work out just how much of the universe is dark. It looks as if dark energy makes up about 68% of the universe and dark matter about 27%, leaving just 5% for us and everything else we can actually see. So what's the dark stuff made of? We don't know, but there's one theory, called supersymmetry, that could explain some of it. Supersymmetry, or SUSY for short, predicts a whole range of new particles, some of which could make up the dark matter. If we found evidence for SUSY, we could go from understanding 5% of our universe, the things we can actually see, to around a third. Not bad for a day's work. Dark energy would probably be harder to understand, but there are some speculative theories out there that might point the way. Among them are theories that go back to that first great idea of the ancient Greeks, the idea that we began with several minutes ago, the idea that the universe must be simple. These theories predict that there is just a single element from which all the universe's wonderful diversity stems, a vibrating string. The idea is that all the particles we know today are just different harmonics on the string. Unfortunately, string theories today are, as yet, untestable. But, with so much of the universe waiting to be explored, the stakes are high. Does all of this make you feel small? It shouldn't. Instead, you should marvel in the fact that, as far as we know, you are a member of the only species in the universe able even to begin to grasp its wonders, and you're living at the right time to see our understanding explode.

Frequently Occurring Word Combinations

ngrams of length 2

collocation	frequency
dark matter	7
dark energy	4
wonderful diversity	2
visible stuff	2

Important Words

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