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Unscramble the Blue Letters

Around 1159 A.D., a mathematician called Bhaskara the Learned sketched a design for a wheel containing curved reservoirs of mecrruy. He reasoned that as the wheels spun, the mercury would flow to the boottm of each reservoir, leaving one side of the wheel perpetually heavier than the other. The imbalance would keep the wheel tnunirg forever. Bhaskara's drawing was one of the earliest designs for a pteuparel motion machine, a device that can do work indefinitely without any external energy source. imagnie a windmill that produced the beezre it needed to keep rotating. Or a lightbulb whose glow provided its own electricity. These devices have captured many inventors' imaginations because they could transform our relationship with energy. For example, if you could biuld a perpetual motion machine that included humans as part of its perfectly efficient system, it could stsiuan life indefinitely. There's just one prlbeom. They don't work. Ideas for perpetual motion machines all violate one or more fundamental laws of thermodynamics, the branch of physics that dcsrieebs the relationship between different forms of energy. The first law of thermodynamics says that energy can't be crateed or destroyed. You can't get out more eengry than you put in. That rules out a useful perpetual motion machine right away because a machine could only ever produce as much energy as it consumed. There wouldn't be any left over to pweor a car or charge a phone. But what if you just wanted the mcnahie to keep itself moving? inntoevrs have proposed ptelny of ideas. Several of these have been variations on Bhaskara's over-balanced wheel with rolling balls or weights on swinging arms. None of them work. The moving parts that make one side of the wheel heavier also shift its center of mass downward below the axle. With a low center of mass, the wheel just swings back and forth like a pendulum, then sotps. What about a different approach? In the 17th century, Robert Boyle came up with an idea for a self-watering pot. He theorized that capillary action, the attraction between liquids and surfaces that pulls wetar through thin tubes, might keep the water cycling around the bowl. But if the capillary action is strong enough to ocmveroe gviatry and draw the water up, it would also prevent it from falilng back into the bowl. Then there are versions with magnets, like this set of ramps. The ball is supposed to be pulled upwards by the mnaget at the top, fall back down through the hole, and repeat the cycle. This one fails because like the self-watering pot, the magnet would simply hold the ball at the top. Even if it somehow did keep moving, the magnet's strength would degrade over time and eventually stop working. For each of these minheacs to keep moving, they'd have to create some extra energy to nudge the system past its stopping point, bnireakg the first law of thermodynamics. There are ones that seem to keep going, but in reality, they invariably turn out to be dwnirag energy from some external source. Even if eneeingrs could somehow design a machine that didn't violate the first law of thermodynamics, it still wouldn't work in the real world because of the second law. The second law of thermodynamics tells us that energy tends to spread out through processes like friction. Any real machine would have moving parts or interactions with air or liquid molecules that would generate tiny amounts of friction and heat, even in a vacuum. That heat is energy escaping, and it would keep leeching out, reducing the energy available to move the system itself until the machine iaevtibnly stopped. So far, these two laws of tamcrnoehidyms have stymied every idea for perpetual motion and the dearms of pfcreelty efficient energy generation they imply. Yet it's hard to conclusively say we'll never dovceisr a perpetual motion machine because there's still so much we don't understand about the universe. Perhaps we'll find new exotic frmos of matter that'll force us to revisit the laws of thermodynamics. Or maybe there's perpetual mtoion on tiny quantum scales. What we can be reasonably sure about is that we'll never stop looking. For now, the one thing that seems truly perpetual is our search.

Open Cloze

Around 1159 A.D., a mathematician called Bhaskara the Learned sketched a design for a wheel containing curved reservoirs of _______. He reasoned that as the wheels spun, the mercury would flow to the ______ of each reservoir, leaving one side of the wheel perpetually heavier than the other. The imbalance would keep the wheel _______ forever. Bhaskara's drawing was one of the earliest designs for a _________ motion machine, a device that can do work indefinitely without any external energy source. _______ a windmill that produced the ______ it needed to keep rotating. Or a lightbulb whose glow provided its own electricity. These devices have captured many inventors' imaginations because they could transform our relationship with energy. For example, if you could _____ a perpetual motion machine that included humans as part of its perfectly efficient system, it could _______ life indefinitely. There's just one _______. They don't work. Ideas for perpetual motion machines all violate one or more fundamental laws of thermodynamics, the branch of physics that _________ the relationship between different forms of energy. The first law of thermodynamics says that energy can't be _______ or destroyed. You can't get out more ______ than you put in. That rules out a useful perpetual motion machine right away because a machine could only ever produce as much energy as it consumed. There wouldn't be any left over to _____ a car or charge a phone. But what if you just wanted the _______ to keep itself moving? _________ have proposed ______ of ideas. Several of these have been variations on Bhaskara's over-balanced wheel with rolling balls or weights on swinging arms. None of them work. The moving parts that make one side of the wheel heavier also shift its center of mass downward below the axle. With a low center of mass, the wheel just swings back and forth like a pendulum, then _____. What about a different approach? In the 17th century, Robert Boyle came up with an idea for a self-watering pot. He theorized that capillary action, the attraction between liquids and surfaces that pulls _____ through thin tubes, might keep the water cycling around the bowl. But if the capillary action is strong enough to ________ _______ and draw the water up, it would also prevent it from _______ back into the bowl. Then there are versions with magnets, like this set of ramps. The ball is supposed to be pulled upwards by the ______ at the top, fall back down through the hole, and repeat the cycle. This one fails because like the self-watering pot, the magnet would simply hold the ball at the top. Even if it somehow did keep moving, the magnet's strength would degrade over time and eventually stop working. For each of these ________ to keep moving, they'd have to create some extra energy to nudge the system past its stopping point, ________ the first law of thermodynamics. There are ones that seem to keep going, but in reality, they invariably turn out to be _______ energy from some external source. Even if _________ could somehow design a machine that didn't violate the first law of thermodynamics, it still wouldn't work in the real world because of the second law. The second law of thermodynamics tells us that energy tends to spread out through processes like friction. Any real machine would have moving parts or interactions with air or liquid molecules that would generate tiny amounts of friction and heat, even in a vacuum. That heat is energy escaping, and it would keep leeching out, reducing the energy available to move the system itself until the machine __________ stopped. So far, these two laws of ______________ have stymied every idea for perpetual motion and the ______ of _________ efficient energy generation they imply. Yet it's hard to conclusively say we'll never ________ a perpetual motion machine because there's still so much we don't understand about the universe. Perhaps we'll find new exotic _____ of matter that'll force us to revisit the laws of thermodynamics. Or maybe there's perpetual ______ on tiny quantum scales. What we can be reasonably sure about is that we'll never stop looking. For now, the one thing that seems truly perpetual is our search.

Solution

1. sustain
2. created
3. stops
4. engineers
5. motion
6. water
7. dreams
8. drawing
9. energy
10. turning
11. build
12. power
13. overcome
14. inevitably
15. problem
16. inventors
17. mercury
18. machine
19. bottom
20. magnet
21. breaking
22. imagine
23. gravity
24. perpetual
25. machines
26. forms
27. perfectly
28. plenty
29. breeze
30. discover
31. thermodynamics
32. falling
33. describes

Original Text

Around 1159 A.D., a mathematician called Bhaskara the Learned sketched a design for a wheel containing curved reservoirs of mercury. He reasoned that as the wheels spun, the mercury would flow to the bottom of each reservoir, leaving one side of the wheel perpetually heavier than the other. The imbalance would keep the wheel turning forever. Bhaskara's drawing was one of the earliest designs for a perpetual motion machine, a device that can do work indefinitely without any external energy source. Imagine a windmill that produced the breeze it needed to keep rotating. Or a lightbulb whose glow provided its own electricity. These devices have captured many inventors' imaginations because they could transform our relationship with energy. For example, if you could build a perpetual motion machine that included humans as part of its perfectly efficient system, it could sustain life indefinitely. There's just one problem. They don't work. Ideas for perpetual motion machines all violate one or more fundamental laws of thermodynamics, the branch of physics that describes the relationship between different forms of energy. The first law of thermodynamics says that energy can't be created or destroyed. You can't get out more energy than you put in. That rules out a useful perpetual motion machine right away because a machine could only ever produce as much energy as it consumed. There wouldn't be any left over to power a car or charge a phone. But what if you just wanted the machine to keep itself moving? Inventors have proposed plenty of ideas. Several of these have been variations on Bhaskara's over-balanced wheel with rolling balls or weights on swinging arms. None of them work. The moving parts that make one side of the wheel heavier also shift its center of mass downward below the axle. With a low center of mass, the wheel just swings back and forth like a pendulum, then stops. What about a different approach? In the 17th century, Robert Boyle came up with an idea for a self-watering pot. He theorized that capillary action, the attraction between liquids and surfaces that pulls water through thin tubes, might keep the water cycling around the bowl. But if the capillary action is strong enough to overcome gravity and draw the water up, it would also prevent it from falling back into the bowl. Then there are versions with magnets, like this set of ramps. The ball is supposed to be pulled upwards by the magnet at the top, fall back down through the hole, and repeat the cycle. This one fails because like the self-watering pot, the magnet would simply hold the ball at the top. Even if it somehow did keep moving, the magnet's strength would degrade over time and eventually stop working. For each of these machines to keep moving, they'd have to create some extra energy to nudge the system past its stopping point, breaking the first law of thermodynamics. There are ones that seem to keep going, but in reality, they invariably turn out to be drawing energy from some external source. Even if engineers could somehow design a machine that didn't violate the first law of thermodynamics, it still wouldn't work in the real world because of the second law. The second law of thermodynamics tells us that energy tends to spread out through processes like friction. Any real machine would have moving parts or interactions with air or liquid molecules that would generate tiny amounts of friction and heat, even in a vacuum. That heat is energy escaping, and it would keep leeching out, reducing the energy available to move the system itself until the machine inevitably stopped. So far, these two laws of thermodynamics have stymied every idea for perpetual motion and the dreams of perfectly efficient energy generation they imply. Yet it's hard to conclusively say we'll never discover a perpetual motion machine because there's still so much we don't understand about the universe. Perhaps we'll find new exotic forms of matter that'll force us to revisit the laws of thermodynamics. Or maybe there's perpetual motion on tiny quantum scales. What we can be reasonably sure about is that we'll never stop looking. For now, the one thing that seems truly perpetual is our search.

Frequently Occurring Word Combinations

ngrams of length 2

collocation frequency
perpetual motion 7
motion machine 3
perfectly efficient 2
moving parts 2

ngrams of length 3

collocation frequency
perpetual motion machine 3

Important Words

1. action
2. air
3. amounts
4. approach
5. arms
6. attraction
7. axle
8. ball
9. balls
11. bottom
12. bowl
13. boyle
14. branch
15. breaking
16. breeze
17. build
18. called
19. capillary
20. captured
21. car
22. center
23. century
24. charge
25. conclusively
26. consumed
27. create
28. created
29. curved
30. cycle
31. cycling
33. describes
34. design
35. designs
36. destroyed
37. device
38. devices
39. discover
40. downward
41. draw
42. drawing
43. dreams
44. earliest
45. efficient
46. electricity
47. energy
48. engineers
49. escaping
50. eventually
51. exotic
52. external
53. extra
54. fails
55. fall
56. falling
57. find
58. flow
59. force
60. forms
61. friction
62. fundamental
63. generate
64. generation
65. glow
66. gravity
67. hard
68. heat
69. heavier
70. hold
71. hole
72. humans
73. idea
74. ideas
75. imaginations
76. imagine
77. imbalance
78. imply
79. included
80. indefinitely
81. inevitably
82. interactions
83. invariably
84. inventors
85. law
86. laws
87. learned
88. leaving
89. leeching
90. left
91. life
92. lightbulb
93. liquid
94. liquids
95. machine
96. machines
97. magnet
98. magnets
99. mass
100. mathematician
101. matter
102. mercury
103. molecules
104. motion
105. move
106. moving
107. needed
108. nudge
109. overcome
110. part
111. parts
112. pendulum
113. perfectly
114. perpetual
115. perpetually
116. phone
117. physics
118. plenty
119. point
120. pot
121. power
122. prevent
123. problem
124. processes
125. produce
126. produced
127. proposed
128. pulled
129. pulls
130. put
131. quantum
132. ramps
133. real
134. reality
135. reasoned
136. reducing
137. relationship
138. repeat
139. reservoir
140. reservoirs
141. revisit
142. robert
143. rolling
144. rotating
145. rules
146. scales
147. search
148. set
149. shift
150. side
151. simply
152. sketched
153. source
155. spun
156. stop
157. stopped
158. stopping
159. stops
160. strength
161. strong
162. stymied
163. supposed
164. surfaces
165. sustain
166. swinging
167. swings
168. system
169. tells
170. theorized
171. thermodynamics
172. thin
173. time
174. tiny
175. top
176. transform
177. tubes
178. turn
179. turning
180. understand
181. universe
182. vacuum
183. variations
184. versions
185. violate
186. wanted
187. water
188. weights
189. wheel
190. wheels
191. windmill
192. work
193. working
194. world