TedTest

From the Ted Talk by Lieven Scheire: How quantum mechanics explains global warming

Unscramble the Blue Letters

You've probably heard that carbon dioxide is warming the Earth, but how does it work? Is it like the glass of a greenhouse or like an insulating blanket? Well, not entirely. The answer involves a bit of quantum mechanics, but don't worry, we'll sartt with a rainbow. If you look csloley at sunlight separated through a prism, you'll see dark gaps where bands of color went missing. Where did they go? Before reaching our eyes, different gases absorbed those specific parts of the scprteum. For example, oxygen gas snatched up some of the dark red light, and sodium gberabd two bands of yellow. But why do these gases absorb specific colors of lihgt? This is where we enter the quantum realm. Every atom and mlelcuoe has a set number of possible ergney levels for its eelrtcnos. To shift its electrons from the ground state to a higher level, a molecule needs to gain a certain amount of energy. No more, no less. It gets that energy from light, which comes in more energy levels than you could count. Light ctosnsis of tiny particles called photons and the amount of energy in each photon corresponds to its color. Red light has lower energy and longer wgnevlhtaes. Purple light has higher energy and shorter wavelengths. Sunlight offers all the photons of the rainbow, so a gas molecule can cohsoe the photons that carry the exact amount of energy needed to shift the molecule to its next energy level. When this match is made, the photon disappers as the molecule gians its energy, and we get a small gap in our rainbow. If a photon crerais too much or too little energy, the molecule has no choice but to let it fly past. This is why glass is tneanprrast. The atoms in glsas do not pair well with any of the energy levels in visible light, so the photons pass through. So, which photons does carbon dioxide prefer? Where is the black line in our rainbow that explains global warming? Well, it's not there. cbroan dioidxe doesn't absorb light directly from the Sun. It absorbs light from a totally different catiseell body. One that doesn't appear to be emitting light at all: Earth. If you're wondering why our planet doesn't seem to be glowing, it's because the etrah doesn't emit visible light. It emits infared light. The light that our eyes can see, including all of the colors of the rainbow, is just a small part of the lagrer spectrum of electromagnetic radiation, which includes radio waves, microwaves, irnfeard, ultraviolet, x-rays, and gamma rays. It may seem strange to think of these things as light, but there is no fmadanetnul difference between visible light and other electromagnetic radiation. It's the same energy, but at a higher or lower level. In fact, it's a bit presumptuous to define the term vbsilie light by our own limitations. After all, infrared light is visible to saknes, and ultraviolet light is visible to bdris. If our eyes were adapted to see light of 1900 megahertz, then a mobile phone would be a flashlight, and a cell phnoe tower would look like a huge lantern. Earth emits infrared raiidoatn because every object with a temperature above absolute zero will emit light. This is called thermal radiation. The hettor an object gets, the heighr frequency the light it emits. When you heat a piece of iron, it will emit more and more fqueeicenrs of infrared light, and then, at a temperature of around 450 degrees Celsius, its light will reach the visible spectrum. At first, it will look red hot. And with even more heat, it will glow white with all of the frequencies of visible light. This is how traditional light bulbs were designed to work and why they're so wasteful. 95% of the light they emit is invisible to our eyes. It's wasted as heat. Earth's infrared radiation would escape to space if there weren't greenhouse gas molecules in our ahomrptee. Just as oxygen gas prefers the dark red photons, carbon dioxide and other gneouserhe gases macth with infrared photons. They provide the right amount of energy to shift the gas molecules into their higher energy level. Shortly after a carbon dioxide molecule abrosbs an infrared ptoohn, it will fall back to its previous energy level, and spit a photon back out in a random direction. Some of that energy then rnrutes to Earth's surface, cniusag winramg. The more carbon dioxide in the atmosphere, the more likely that infrared poonths will land back on Earth and change our climate.

Open Cloze

You've probably heard that carbon dioxide is warming the Earth, but how does it work? Is it like the glass of a greenhouse or like an insulating blanket? Well, not entirely. The answer involves a bit of quantum mechanics, but don't worry, we'll _____ with a rainbow. If you look _______ at sunlight separated through a prism, you'll see dark gaps where bands of color went missing. Where did they go? Before reaching our eyes, different gases absorbed those specific parts of the ________. For example, oxygen gas snatched up some of the dark red light, and sodium _______ two bands of yellow. But why do these gases absorb specific colors of _____? This is where we enter the quantum realm. Every atom and ________ has a set number of possible ______ levels for its _________. To shift its electrons from the ground state to a higher level, a molecule needs to gain a certain amount of energy. No more, no less. It gets that energy from light, which comes in more energy levels than you could count. Light ________ of tiny particles called photons and the amount of energy in each photon corresponds to its color. Red light has lower energy and longer ___________. Purple light has higher energy and shorter wavelengths. Sunlight offers all the photons of the rainbow, so a gas molecule can ______ the photons that carry the exact amount of energy needed to shift the molecule to its next energy level. When this match is made, the photon disappers as the molecule _____ its energy, and we get a small gap in our rainbow. If a photon _______ too much or too little energy, the molecule has no choice but to let it fly past. This is why glass is ___________. The atoms in _____ do not pair well with any of the energy levels in visible light, so the photons pass through. So, which photons does carbon dioxide prefer? Where is the black line in our rainbow that explains global warming? Well, it's not there. ______ _______ doesn't absorb light directly from the Sun. It absorbs light from a totally different _________ body. One that doesn't appear to be emitting light at all: Earth. If you're wondering why our planet doesn't seem to be glowing, it's because the _____ doesn't emit visible light. It emits infared light. The light that our eyes can see, including all of the colors of the rainbow, is just a small part of the ______ spectrum of electromagnetic radiation, which includes radio waves, microwaves, ________, ultraviolet, x-rays, and gamma rays. It may seem strange to think of these things as light, but there is no ___________ difference between visible light and other electromagnetic radiation. It's the same energy, but at a higher or lower level. In fact, it's a bit presumptuous to define the term _______ light by our own limitations. After all, infrared light is visible to ______, and ultraviolet light is visible to _____. If our eyes were adapted to see light of 1900 megahertz, then a mobile phone would be a flashlight, and a cell _____ tower would look like a huge lantern. Earth emits infrared _________ because every object with a temperature above absolute zero will emit light. This is called thermal radiation. The ______ an object gets, the ______ frequency the light it emits. When you heat a piece of iron, it will emit more and more ___________ of infrared light, and then, at a temperature of around 450 degrees Celsius, its light will reach the visible spectrum. At first, it will look red hot. And with even more heat, it will glow white with all of the frequencies of visible light. This is how traditional light bulbs were designed to work and why they're so wasteful. 95% of the light they emit is invisible to our eyes. It's wasted as heat. Earth's infrared radiation would escape to space if there weren't greenhouse gas molecules in our _________. Just as oxygen gas prefers the dark red photons, carbon dioxide and other __________ gases _____ with infrared photons. They provide the right amount of energy to shift the gas molecules into their higher energy level. Shortly after a carbon dioxide molecule _______ an infrared ______, it will fall back to its previous energy level, and spit a photon back out in a random direction. Some of that energy then _______ to Earth's surface, _______ _______. The more carbon dioxide in the atmosphere, the more likely that infrared _______ will land back on Earth and change our climate.

Solution

choose
photon
dioxide
phone
molecule
spectrum
photons
higher
warming
energy
radiation
glass
closely
carries
wavelengths
birds
start
electrons
frequencies
greenhouse
match
causing
absorbs
atmophere
infrared
fundamental
grabbed
larger
gains
transparent
carbon
light
hotter
earth
returns
celestial
consists
visible
snakes

Original Text

You've probably heard that carbon dioxide is warming the Earth, but how does it work? Is it like the glass of a greenhouse or like an insulating blanket? Well, not entirely. The answer involves a bit of quantum mechanics, but don't worry, we'll start with a rainbow. If you look closely at sunlight separated through a prism, you'll see dark gaps where bands of color went missing. Where did they go? Before reaching our eyes, different gases absorbed those specific parts of the spectrum. For example, oxygen gas snatched up some of the dark red light, and sodium grabbed two bands of yellow. But why do these gases absorb specific colors of light? This is where we enter the quantum realm. Every atom and molecule has a set number of possible energy levels for its electrons. To shift its electrons from the ground state to a higher level, a molecule needs to gain a certain amount of energy. No more, no less. It gets that energy from light, which comes in more energy levels than you could count. Light consists of tiny particles called photons and the amount of energy in each photon corresponds to its color. Red light has lower energy and longer wavelengths. Purple light has higher energy and shorter wavelengths. Sunlight offers all the photons of the rainbow, so a gas molecule can choose the photons that carry the exact amount of energy needed to shift the molecule to its next energy level. When this match is made, the photon disappers as the molecule gains its energy, and we get a small gap in our rainbow. If a photon carries too much or too little energy, the molecule has no choice but to let it fly past. This is why glass is transparent. The atoms in glass do not pair well with any of the energy levels in visible light, so the photons pass through. So, which photons does carbon dioxide prefer? Where is the black line in our rainbow that explains global warming? Well, it's not there. Carbon dioxide doesn't absorb light directly from the Sun. It absorbs light from a totally different celestial body. One that doesn't appear to be emitting light at all: Earth. If you're wondering why our planet doesn't seem to be glowing, it's because the Earth doesn't emit visible light. It emits infared light. The light that our eyes can see, including all of the colors of the rainbow, is just a small part of the larger spectrum of electromagnetic radiation, which includes radio waves, microwaves, infrared, ultraviolet, x-rays, and gamma rays. It may seem strange to think of these things as light, but there is no fundamental difference between visible light and other electromagnetic radiation. It's the same energy, but at a higher or lower level. In fact, it's a bit presumptuous to define the term visible light by our own limitations. After all, infrared light is visible to snakes, and ultraviolet light is visible to birds. If our eyes were adapted to see light of 1900 megahertz, then a mobile phone would be a flashlight, and a cell phone tower would look like a huge lantern. Earth emits infrared radiation because every object with a temperature above absolute zero will emit light. This is called thermal radiation. The hotter an object gets, the higher frequency the light it emits. When you heat a piece of iron, it will emit more and more frequencies of infrared light, and then, at a temperature of around 450 degrees Celsius, its light will reach the visible spectrum. At first, it will look red hot. And with even more heat, it will glow white with all of the frequencies of visible light. This is how traditional light bulbs were designed to work and why they're so wasteful. 95% of the light they emit is invisible to our eyes. It's wasted as heat. Earth's infrared radiation would escape to space if there weren't greenhouse gas molecules in our atmophere. Just as oxygen gas prefers the dark red photons, carbon dioxide and other greenhouse gases match with infrared photons. They provide the right amount of energy to shift the gas molecules into their higher energy level. Shortly after a carbon dioxide molecule absorbs an infrared photon, it will fall back to its previous energy level, and spit a photon back out in a random direction. Some of that energy then returns to Earth's surface, causing warming. The more carbon dioxide in the atmosphere, the more likely that infrared photons will land back on Earth and change our climate.

Frequently Occurring Word Combinations

ngrams of length 2

collocation	frequency
carbon dioxide	6
visible light	4
energy levels	3
oxygen gas	2
dark red	2
higher energy	2
energy level	2
infrared radiation	2
gas molecules	2
infrared photons	2

Important Words

absolute
absorb
absorbed
absorbs
adapted
amount
answer
atmophere
atmosphere
atom
atoms
bands
birds
bit
black
blanket
body
bulbs
called
carbon
carries
carry
causing
celestial
cell
celsius
change
choice
choose
climate
closely
color
colors
consists
corresponds
count
dark
define
degrees
designed
difference
dioxide
direction
disappers
earth
electromagnetic
electrons
emit
emits
emitting
energy
enter
escape
exact
explains
eyes
fact
fall
flashlight
fly
frequencies
frequency
fundamental
gain
gains
gamma
gap
gaps
gas
gases
glass
global
glow
glowing
grabbed
greenhouse
ground
heard
heat
higher
hot
hotter
huge
includes
including
infared
infrared
insulating
invisible
involves
iron
land
lantern
larger
level
levels
light
limitations
line
longer
match
mechanics
megahertz
microwaves
missing
mobile
molecule
molecules
needed
number
object
offers
oxygen
pair
part
particles
parts
pass
phone
photon
photons
piece
planet
prefer
prefers
presumptuous
previous
prism
provide
purple
quantum
radiation
radio
rainbow
random
rays
reach
reaching
realm
red
returns
separated
set
shift
shorter
shortly
small
snakes
snatched
sodium
space
specific
spectrum
spit
start
state
strange
sun
sunlight
surface
temperature
term
thermal
tiny
totally
tower
traditional
transparent
ultraviolet
visible
warming
wasted
wasteful
wavelengths
waves
white
wondering
work
worry
yellow