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 geusnhoere or like an itnnsliaug bnlekat? Well, not entirely. The answer ivevlons 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 raeinhcg our eyes, different gases absorbed those specific patrs 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 gesas absorb specific colors of light? This is where we etner the quantum relam. Every atom and molecule has a set number of possible energy levels for its electrons. To shift its electrons from the ground satte 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 cloor. Red light has lower energy and leognr wavelengths. plrpue light has higher energy and shorter welagnvhtes. 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 gians 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 trnespraant. The atoms in glass do not pair well with any of the energy levels in visible light, so the photons pass through. So, which poonhts does carbon dioxide prefer? Where is the black line in our rainbow that explains gblaol warming? Well, it's not there. Carbon doxdiie doesn't absorb light directly from the Sun. It abrboss light from a totally different citaeslel body. One that doesn't appear to be enimtitg light at all: etarh. 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 fdamnnautel difference between visible light and other electromagnetic radiation. It's the same energy, but at a hhiger or lower leevl. In fact, it's a bit presumptuous to define the term viilbse 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 lgiht 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 ficneureeqs of infrared light, and then, at a temperature of around 450 dgeeers culiess, its light will reach the visible spectrum. At first, it will look red hot. And with even more heat, it will glow wtihe 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 inlsibive 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, cbroan dioxide and other greenhouse gases mtach with ifarenrd photons. They provide the right auomnt of energy to sfhit the gas melueocls into their higher enegry 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, csinaug warming. The more carbon dioxide in the atmosphere, the more likely that infrared photons 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 __________ or like an __________ _______? Well, not entirely. The answer ________ 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 ________ our eyes, different gases absorbed those specific _____ 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 _____ absorb specific colors of light? This is where we _____ the quantum _____. Every atom and molecule has a set number of possible energy levels for its electrons. To shift its electrons from the ground _____ 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 _____. Red light has lower energy and ______ wavelengths. ______ light has higher energy and shorter ___________. 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 _____ 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 ___________. The atoms in glass do not pair well with any of the energy levels in visible light, so the photons pass through. So, which _______ does carbon dioxide prefer? Where is the black line in our rainbow that explains ______ warming? Well, it's not there. Carbon _______ doesn't absorb light directly from the Sun. It _______ light from a totally different _________ body. One that doesn't appear to be ________ light at all: _____. 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 ___________ difference between visible light and other electromagnetic radiation. It's the same energy, but at a ______ or lower _____. In fact, it's a bit presumptuous to define the term _______ 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 _____ 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 ___________ of infrared light, and then, at a temperature of around 450 _______ _______, its light will reach the visible spectrum. At first, it will look red hot. And with even more heat, it will glow _____ 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 _________ 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, ______ dioxide and other greenhouse gases _____ with ________ photons. They provide the right ______ of energy to _____ the gas _________ into their higher ______ 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, _______ warming. The more carbon dioxide in the atmosphere, the more likely that infrared photons will land back on Earth and change our climate.

Solution

blanket
greenhouse
gases
gains
involves
emitting
higher
color
celsius
state
infrared
degrees
visible
dioxide
causing
longer
energy
celestial
white
shift
enter
insulating
realm
light
purple
reaching
transparent
level
match
molecules
carbon
amount
wavelengths
fundamental
parts
invisible
earth
frequencies
global
absorbs
photons

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