TedTest

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

Unscramble the Blue Letters

The ainnect Greeks had a great idea: The universe is simple. In their mnids, 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 cibnomnig the four basic elements in different ways, you could produce all the wrfouendl diversity of the universe. etrah 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 bsais of experimental science. Worse still, the theory was wnrog. 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 secitfinic ideas ever. Everything we see is made up of tiny, indivisible bits of stuff called aotms. This thoery is simple and elegant, and it has the advantage over the earth, air, fire, and waetr theory of being right. ceutrines of scientific thought and eaentoiipemxrtn have established that the real eltmenes, 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 rcigbeonalze 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 bucneos 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 glclfrauey 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 vbilsie stuff in those groups to hold them together. Later measurements of individual gelaaixs confirmed this puzzling result. There's smpily not enough visible sutff in galaxies to provide enough gaitvry 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 aoetlrgfw of the Big Bang, but that's another story. All of the evidence we have says that dark matter is there and it atcnoucs 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 hveaens do not revolve around us and that we're residents of a fairly oirarndy planet, oirintbg a fairly ordinary star, in the spiral arm of a fairly ordinary glxaay. The dircevosy 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. elary this century, scientists sdtunyig the oetur 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 aeetcralce 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 eenrgy 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, claeld 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 eivndece 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 gkeers, the idea that we began with several minutes ago, the idea that the universe must be simple. These tohieres predict that there is just a single element from which all the universe's wonderful diversity stems, a vriabting string. The idea is that all the particles we know today are just different homcnaris on the string. Unfortunately, string theories taody are, as yet, untestable. But, with so much of the uneirsve 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 _______ Greeks had a great idea: The universe is simple. In their _____, 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 _________ the four basic elements in different ways, you could produce all the _________ diversity of the universe. _____ 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 _____ of experimental science. Worse still, the theory was _____. 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 __________ ideas ever. Everything we see is made up of tiny, indivisible bits of stuff called _____. This ______ is simple and elegant, and it has the advantage over the earth, air, fire, and _____ theory of being right. _________ of scientific thought and _______________ have established that the real ________, 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 ____________ 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 _______ 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 __________ 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 _______ stuff in those groups to hold them together. Later measurements of individual ________ confirmed this puzzling result. There's ______ not enough visible _____ in galaxies to provide enough _______ 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 _________ of the Big Bang, but that's another story. All of the evidence we have says that dark matter is there and it ________ 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 _______ do not revolve around us and that we're residents of a fairly ________ planet, ________ a fairly ordinary star, in the spiral arm of a fairly ordinary ______. The _________ 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. _____ this century, scientists ________ the _____ 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 __________ 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 ______ 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, ______ 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 ________ 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 ______, the idea that we began with several minutes ago, the idea that the universe must be simple. These ________ predict that there is just a single element from which all the universe's wonderful diversity stems, a _________ string. The idea is that all the particles we know today are just different _________ on the string. Unfortunately, string theories _____ are, as yet, untestable. But, with so much of the ________ 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

ordinary
centuries
accounts
minds
simply
accelerate
bounces
heavens
galaxy
scientific
combining
outer
studying
universe
evidence
experimentation
discovery
called
wonderful
gravity
wrong
gracefully
earth
early
harmonics
elements
ancient
basis
afterglow
energy
water
today
stuff
vibrating
theories
orbiting
atoms
greeks
galaxies
recognizable
visible
theory

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

accelerate
accelerating
acceleration
accounts
advantage
afterglow
air
amount
ancient
appears
arm
atom
atoms
background
bad
bang
basic
basis
beautiful
began
behave
big
bit
bits
bounces
broken
call
called
car
carbon
center
centuries
century
combining
confirmed
contained
cosmic
dark
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discovery
diversity
divisible
driving
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earth
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elegant
element
elements
enduring
energy
established
evidence
expansion
expect
experimental
experimentation
explain
explode
explored
fact
feel
fill
fire
fly
fraction
galaxies
galaxy
give
gracefully
grasp
gravity
great
greeks
groups
harder
harmonics
heavens
high
hold
hot
hydrogen
idea
ideas
individual
indivisible
iron
kind
leave
leaving
leucippus
light
live
living
long
marvel
matter
measured
measurement
measurements
member
microwave
miletus
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minutes
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moving
needed
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planet
point
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produce
profound
provide
pushing
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range
rare
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real
recognizable
residents
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result
revolve
science
scientific
scientists
shapes
short
simple
simplicity
simplistic
simply
single
small
smallest
space
species
speculative
spinning
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stakes
star
stars
stems
step
story
string
studying
stuff
supersymmetry
surprise
susy
theories
theory
thought
time
tiny
today
told
turns
understand
understanding
universe
untestable
vibrating
visible
waiting
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ways
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wet
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work
worse
wrong