TedTest

From the Ted Talk by Chad Orzel: What is the Heisenberg Uncertainty Principle?

Unscramble the Blue Letters

The Heisenberg Uncertainty Principle is one of a handful of ideas from quantum physics to exanpd into general pop culture. It says that you can never simultaneously know the exact position and the eacxt speed of an object and shows up as a metaphor in everything from literary csiciritm to spotrs commentary. Uncertainty is often explained as a result of measurement, that the act of measuring an object's position changes its speed, or vice versa. The real origin is much deeepr and more amazing. The Uncertainty prplicine exists because everything in the uevsrine behaves like both a particle and a wave at the same time. In quantum mechanics, the exact position and exact speed of an object have no meaning. To userndatnd this, we need to think about what it means to behave like a particle or a wave. piratcles, by definition, exist in a single place at any instant in time. We can represent this by a graph showing the probability of finding the object at a particular place, which looks like a spike, 100% at one specific position, and zero everywhere else. Waves, on the other hand, are disturbances spread out in space, like ripples covering the surface of a pond. We can clearly identify features of the wave pattern as a whole, most importantly, its waventgleh, which is the distance between two neighboring pkaes, or two neighboring vlaelys. But we can't assign it a single position. It has a good probability of being in lots of different places. Wavelength is essential for quantum physics because an object's wavelength is related to its momentum, mass times velocity. A fast-moving object has lots of momentum, which corresponds to a very short wavelength. A haevy object has lots of momentum even if it's not moving very fast, which again means a very short wavelength. This is why we don't ntioce the wave nature of everyday ocejbts. If you toss a baseball up in the air, its wavelength is a billionth of a trillionth of a tllitrnoih of a meter, far too tiny to ever deectt. salml things, like atoms or electrons though, can have wathnleegvs big enough to measure in physics experiments. So, if we have a pure wave, we can measure its wavelength, and thus its momentum, but it has no position. We can know a particles position very well, but it doesn't have a wavelength, so we don't know its momentum. To get a particle with both piitsoon and momentum, we need to mix the two pictures to make a graph that has waves, but only in a small area. How can we do this? By combining waves with different wavelengths, which means giving our qaunutm object some possibility of having different momenta. When we add two waves, we find that there are places where the peaks line up, making a bigger wave, and other pleacs where the peaks of one fill in the valleys of the other. The rsluet has regions where we see waves separated by regions of nothing at all. If we add a third wave, the regions where the waves cancel out get bigger, a fourth and they get bigger still, with the wavier regions becoming narrower. If we keep adding waves, we can make a wave packet with a clear wavelength in one small region. That's a quantum oejcbt with both wave and ptlrciae nature, but to asmcpcoilh this, we had to lose certainty about both position and momentum. The positions isn't restricted to a single point. There's a good probability of finding it within some rgane of the center of the wave packet, and we made the wave packet by adding lots of waves, which means there's some probability of finding it with the momentum corresponding to any one of those. Both position and mnomteum are now uncertain, and the uncertainties are ctconeend. If you want to reduce the position uncertainty by making a smaller wave packet, you need to add more wevas, which means a bgiegr momentum uncertainty. If you want to know the momentum better, you need a bigger wave packet, which mneas a bigger position uncertainty. That's the Heisenberg Uncertainty Principle, first stated by German physicist wneerr Heisenberg back in 1927. This uncertainty isn't a matter of mrusaeing well or bdlay, but an inevitable result of combining particle and wave nature. The Uncertainty Principle isn't just a practical limit on measurment. It's a limit on what properties an object can have, built into the fmduteaannl structure of the universe itself.

Open Cloze

The Heisenberg Uncertainty Principle is one of a handful of ideas from quantum physics to ______ into general pop culture. It says that you can never simultaneously know the exact position and the _____ speed of an object and shows up as a metaphor in everything from literary _________ to ______ commentary. Uncertainty is often explained as a result of measurement, that the act of measuring an object's position changes its speed, or vice versa. The real origin is much ______ and more amazing. The Uncertainty _________ exists because everything in the ________ behaves like both a particle and a wave at the same time. In quantum mechanics, the exact position and exact speed of an object have no meaning. To __________ this, we need to think about what it means to behave like a particle or a wave. _________, by definition, exist in a single place at any instant in time. We can represent this by a graph showing the probability of finding the object at a particular place, which looks like a spike, 100% at one specific position, and zero everywhere else. Waves, on the other hand, are disturbances spread out in space, like ripples covering the surface of a pond. We can clearly identify features of the wave pattern as a whole, most importantly, its __________, which is the distance between two neighboring _____, or two neighboring _______. But we can't assign it a single position. It has a good probability of being in lots of different places. Wavelength is essential for quantum physics because an object's wavelength is related to its momentum, mass times velocity. A fast-moving object has lots of momentum, which corresponds to a very short wavelength. A _____ object has lots of momentum even if it's not moving very fast, which again means a very short wavelength. This is why we don't ______ the wave nature of everyday _______. If you toss a baseball up in the air, its wavelength is a billionth of a trillionth of a __________ of a meter, far too tiny to ever ______. _____ things, like atoms or electrons though, can have ___________ big enough to measure in physics experiments. So, if we have a pure wave, we can measure its wavelength, and thus its momentum, but it has no position. We can know a particles position very well, but it doesn't have a wavelength, so we don't know its momentum. To get a particle with both ________ and momentum, we need to mix the two pictures to make a graph that has waves, but only in a small area. How can we do this? By combining waves with different wavelengths, which means giving our _______ object some possibility of having different momenta. When we add two waves, we find that there are places where the peaks line up, making a bigger wave, and other ______ where the peaks of one fill in the valleys of the other. The ______ has regions where we see waves separated by regions of nothing at all. If we add a third wave, the regions where the waves cancel out get bigger, a fourth and they get bigger still, with the wavier regions becoming narrower. If we keep adding waves, we can make a wave packet with a clear wavelength in one small region. That's a quantum ______ with both wave and ________ nature, but to __________ this, we had to lose certainty about both position and momentum. The positions isn't restricted to a single point. There's a good probability of finding it within some _____ of the center of the wave packet, and we made the wave packet by adding lots of waves, which means there's some probability of finding it with the momentum corresponding to any one of those. Both position and ________ are now uncertain, and the uncertainties are _________. If you want to reduce the position uncertainty by making a smaller wave packet, you need to add more _____, which means a ______ momentum uncertainty. If you want to know the momentum better, you need a bigger wave packet, which _____ a bigger position uncertainty. That's the Heisenberg Uncertainty Principle, first stated by German physicist ______ Heisenberg back in 1927. This uncertainty isn't a matter of _________ well or _____, but an inevitable result of combining particle and wave nature. The Uncertainty Principle isn't just a practical limit on measurment. It's a limit on what properties an object can have, built into the ___________ structure of the universe itself.

Solution

heavy
places
fundamental
criticism
peaks
bigger
small
particle
range
position
accomplish
principle
momentum
deeper
wavelengths
object
objects
expand
universe
detect
particles
measuring
badly
notice
waves
understand
sports
quantum
exact
werner
result
trillionth
wavelength
connected
means
valleys

Original Text

The Heisenberg Uncertainty Principle is one of a handful of ideas from quantum physics to expand into general pop culture. It says that you can never simultaneously know the exact position and the exact speed of an object and shows up as a metaphor in everything from literary criticism to sports commentary. Uncertainty is often explained as a result of measurement, that the act of measuring an object's position changes its speed, or vice versa. The real origin is much deeper and more amazing. The Uncertainty Principle exists because everything in the universe behaves like both a particle and a wave at the same time. In quantum mechanics, the exact position and exact speed of an object have no meaning. To understand this, we need to think about what it means to behave like a particle or a wave. Particles, by definition, exist in a single place at any instant in time. We can represent this by a graph showing the probability of finding the object at a particular place, which looks like a spike, 100% at one specific position, and zero everywhere else. Waves, on the other hand, are disturbances spread out in space, like ripples covering the surface of a pond. We can clearly identify features of the wave pattern as a whole, most importantly, its wavelength, which is the distance between two neighboring peaks, or two neighboring valleys. But we can't assign it a single position. It has a good probability of being in lots of different places. Wavelength is essential for quantum physics because an object's wavelength is related to its momentum, mass times velocity. A fast-moving object has lots of momentum, which corresponds to a very short wavelength. A heavy object has lots of momentum even if it's not moving very fast, which again means a very short wavelength. This is why we don't notice the wave nature of everyday objects. If you toss a baseball up in the air, its wavelength is a billionth of a trillionth of a trillionth of a meter, far too tiny to ever detect. Small things, like atoms or electrons though, can have wavelengths big enough to measure in physics experiments. So, if we have a pure wave, we can measure its wavelength, and thus its momentum, but it has no position. We can know a particles position very well, but it doesn't have a wavelength, so we don't know its momentum. To get a particle with both position and momentum, we need to mix the two pictures to make a graph that has waves, but only in a small area. How can we do this? By combining waves with different wavelengths, which means giving our quantum object some possibility of having different momenta. When we add two waves, we find that there are places where the peaks line up, making a bigger wave, and other places where the peaks of one fill in the valleys of the other. The result has regions where we see waves separated by regions of nothing at all. If we add a third wave, the regions where the waves cancel out get bigger, a fourth and they get bigger still, with the wavier regions becoming narrower. If we keep adding waves, we can make a wave packet with a clear wavelength in one small region. That's a quantum object with both wave and particle nature, but to accomplish this, we had to lose certainty about both position and momentum. The positions isn't restricted to a single point. There's a good probability of finding it within some range of the center of the wave packet, and we made the wave packet by adding lots of waves, which means there's some probability of finding it with the momentum corresponding to any one of those. Both position and momentum are now uncertain, and the uncertainties are connected. If you want to reduce the position uncertainty by making a smaller wave packet, you need to add more waves, which means a bigger momentum uncertainty. If you want to know the momentum better, you need a bigger wave packet, which means a bigger position uncertainty. That's the Heisenberg Uncertainty Principle, first stated by German physicist Werner Heisenberg back in 1927. This uncertainty isn't a matter of measuring well or badly, but an inevitable result of combining particle and wave nature. The Uncertainty Principle isn't just a practical limit on measurment. It's a limit on what properties an object can have, built into the fundamental structure of the universe itself.

Frequently Occurring Word Combinations

ngrams of length 2

collocation	frequency
uncertainty principle	3
heisenberg uncertainty	2
quantum physics	2
exact position	2
exact speed	2
good probability	2
short wavelength	2
wave nature	2
quantum object	2
wave packet	2
position uncertainty	2

Important Words

accomplish
act
add
adding
air
amazing
area
assign
atoms
badly
baseball
behave
behaves
big
bigger
billionth
built
cancel
center
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connected
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culture
deeper
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distance
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electrons
essential
everyday
exact
exist
exists
expand
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fast
features
fill
find
finding
fourth
fundamental
general
german
giving
good
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hand
handful
heavy
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identify
importantly
inevitable
instant
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literary
lose
lots
making
mass
matter
meaning
means
measure
measurement
measuring
measurment
mechanics
metaphor
meter
mix
momenta
momentum
moving
narrower
nature
neighboring
notice
object
objects
origin
packet
particle
particles
pattern
peaks
physicist
physics
pictures
place
places
point
pond
pop
position
positions
possibility
practical
principle
probability
properties
pure
quantum
range
real
reduce
region
regions
related
represent
restricted
result
ripples
separated
short
showing
shows
simultaneously
single
small
smaller
space
specific
speed
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spread
stated
structure
surface
time
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tiny
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understand
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velocity
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vice
wave
wavelength
wavelengths
waves
wavier
werner