MOTION MOUNTAIN

More documents

Recommendations

Info

206 5 electromagneticeffects graupel electric field – – – – – + + + + + – + – ++ – + F I G U R E 154 The charging and discharging of clouds: the most probable microscopic mechanism, namely charging of graupel particles by collision with ice particles, the cloud charge distribution, the three-dimensional structure and the large scale processes discovered in the past decades from aeroplanes (© nordique, NASA, NOAA).
electromagnetic effects and challenges 207 Challenge 202 s Ref. 160 Ref. 161 Challenge 203 s if you are completely wet, as in that case the current will flow outside the skin. Usually, wet people who are hit lose all their clothes, as the evaporating water tears them off. Rapid resuscitation is essential to help somebody to recover after a hit.* As a note, you might know how to measure the distance of a lightning by counting the seconds between the lightning and the thunder and multiplying this by the speed of sound,330 m/s; it is less well known that one can estimate thelength of the lightning bolt by measuring theduration of the thunder, and multiplying it by the same factor. In the 1990s more electrical details about thunderstorms became known. Airline pilots and passengers sometime see weak and coloured light emissions spreading from the top of thunderclouds. There are various types of such emissions: blue jets and mostly red sprites and elves, which are somehow due to electric fields between the cloud top and the ionosphere.The details are still under investigation, and the mechanisms are not yet clear.** Lightning is part of the electrical circuit around the Earth.This fascinating part of geophysicswouldleadustoofarfromtheaimofouradventure. But every physicist should know that there is a vertical electric field of between 100 and300 V/m on a clear day, as discovered already in 1752. (Can you guess why it is not noticeable in everyday life? And why despite its value it cannot be used to extract large amounts of energy?) The field is directed from the ionosphere down towards the ground; in fact the Earth is permanently negatively charged, and in clear weather current flows downwards (electrons flow upwards) through the clear atmosphere, trying to discharge our planet. The current of about 1 to2 kA is spread over the whole planet; it is possibly due to the ions formed by cosmic radiation. (The resistance between the ground and the ionosphere is about200Ω, so the total voltage drop is about200 kV.) At the same time, the Earth is constantly beingchargedbyseveral effects: there is a dynamo effect due to the tides of the atmosphere and there are currents induced by the magnetosphere. But the most important charging effect is lightning. In other words, contrary to what one may think, lightning does not discharge the ground, it actually charges it up!*** Of course, lightning does discharge the cloud to ground potential difference; but by doing so, it actually sends (usually) a negative charge down to the Earth as a whole. Thunderclouds are batteries; the energy from the batteries comes from the thermal uplifts mentioned above, which transport charge against the global ambient electrical field. Using a few electrical measurement stations that measure the variations of the electricalfieldoftheEarthitispossibletolocatethepositionofallthelightningthatcomes down towards the Earth at a given moment. (Distributed around the world, there are about a hundred lightning flashes per second.) Present research also aims at measuring the activity of the related electrical sprites and elves in this way. The ions in air play a role in the charging of thunderclouds via the charging of ice crystals and rain drops. In general, all small particles in the air are electrically charged. When aeroplanes and helicopters fly, they usually hit more particles of one charge than * Ifyou are everhit by lightning and survive,go to the hospital! Many people died three days later having failedtodoso.Alightningstrikeoftenleadstocoagulation effectsintheblood.Thesesubstancesblockthe kidneys,andonecandiethreedayslaterbecauseofkidneyfailure.Theremedyistohavedialysistreatment. ** For images, have a look at the interesting elf.gi.alaska.edu/, www.fma-research.com/spriteres.htm and pasko.ee.psu.edu/Nature websites. ***TheEarthisthuscharged toabout−1 MC.Canyou confirmthis? Motion Mountain – The Adventure of Physics copyright © Christoph Schiller June 1990–November 2015 free pdf file available at www.motionmountain.net
Page 1:
ChristophSchiller MOTION MOUNTAIN t
Page 4 and 5:
Editiovicesima octava. Proprietassc
Page 6 and 7:
DieMenschenstärken,die Sachenklär
Page 8 and 9:
8 preface PHYSICS: Describing motio
Page 10 and 11:
10 preface Your donation to the cha
Page 12 and 13:
12 contents Do we see what exists?
Page 14 and 15:
Light, Charges and Brains Inourques
Page 16 and 17:
16 1 electricity and fields F I G U
Page 18 and 19:
18 1 electricityandfields F I G U R
Page 20 and 21:
20 1 electricity and fields nylon r
Page 22 and 23:
Page 24 and 25:
24 1 electricity and fields TA B L
Page 26 and 27:
Page 28 and 29:
28 1 electricity and fields Challen
Page 30 and 31:
30 1 electricity and fields If elec
Page 32 and 33:
Page 34 and 35:
34 1 electricityandfields F I G U R
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
42 1 electricity and fields Oersted
Page 44 and 45:
44 1 electricity and fields Vol. IV
Page 46 and 47:
Page 48 and 49:
48 1 electricity and fields Ref. 24
Page 50 and 51:
50 1 electricity and fields Page 21
Page 52 and 53:
52 1 electricity and fields Ref. 29
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
64 1 electricity and fields battery
Page 66 and 67:
Page 68 and 69:
68 1 electricity and fields e πdU
Page 70 and 71:
70 1 electricity and fields C 1 ins
Page 72 and 73:
Page 74 and 75:
Vol. IV, page 231 Chapter 2 THE DES
Page 76 and 77:
76 2 the description of electromagn
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Chapter 3 WHAT IS LIGHT? Ref. 57 Pa
Page 96 and 97:
96 3 what is light? Electric field
Page 98 and 99:
98 3 what is light? spark transmitt
Page 100 and 101:
100 3 what is light? Ref. 59 Page 1
Page 102 and 103:
102 3 what is light? primary infrar
Page 104 and 105:
104 3 what is light? Page 84 gases
Page 106 and 107:
106 3 what is light? Fre - Waveleng
Page 108 and 109:
108 3 what is light? Challenge 110
Page 110 and 111:
110 3 what is light? incoming light
Page 112 and 113:
112 3 what is light? Ref. 70 Challe
Page 114 and 115:
114 3 what is light? F I G U R E 69
Page 116 and 117:
116 3 what is light? light Ref. 72
Page 118 and 119:
118 3 what is light? light Challeng
Page 120 and 121:
120 3 what is light? momentumLis gi
Page 122 and 123:
122 3 what is light? Ref. 80 Challe
Page 124 and 125:
Page 126 and 127:
126 3 what is light? Ref. 87 Page 9
Page 128 and 129:
Page 130 and 131:
130 3 what is light? v ph v So F I
Page 132 and 133:
132 3 what is light? The forerunner
Page 134 and 135:
134 3 what is light? vocabulary. On
Page 136 and 137:
136 3 what is light? source beam sp
Page 138 and 139:
138 3 what is light? B B Beam in A
Page 140 and 141:
Chapter 4 IMAGES AND THE EYE - OPTI
Page 142 and 143:
142 4 images and the eye - optics 2
Page 144 and 145:
144 4 images and the eye - optics C
Page 146 and 147:
146 4 images and the eye - optics R
Page 148 and 149:
148 4 images and the eye - optics T
Page 150 and 151:
150 4 images and the eye - optics s
Page 152 and 153:
152 4 images and the eye - optics P
Page 154 and 155:
154 4 images and the eye - optics C
Page 156 and 157: 156 4 images and the eye - optics f
Page 158 and 159: 158 4 images and the eye - optics C
Page 160 and 161: 160 4 images and the eye - optics
Page 162 and 163: 162 4 images and the eye - optics R
Page 164 and 165: 164 4 images and the eye - optics P
Page 166 and 167: 166 4 images and the eye - optics b
Page 168 and 169: 168 4 imagesandthe eye-optics F I G
Page 170 and 171: 170 4 images and the eye - optics F
Page 176 and 177: 176 4 images and the eye - optics X
Page 182 and 183: 182 4 imagesandthe eye-optics F I G
Page 188 and 189: 188 4 images and the eye - optics g
Page 190 and 191: 190 4 images and the eye - optics G
Page 196 and 197: 196 4 images and the eye - optics T
Page 204 and 205: Chapter 5 ELECTROMAGNETIC EFFECTS R
Page 208 and 209: 208 5 electromagnetic effects Ref.
Page 214 and 215: 214 5 electromagnetic effects F I G
Page 216 and 217: 216 5 electromagnetic effects TA B
Page 226 and 227: 226 5 electromagnetic effects Chall
Page 228 and 229: 228 5 electromagnetic effects The t
Page 230 and 231: 230 6 classical electrodynamics Pag
Page 232 and 233: 232 6 classical electrodynamics Cha
Page 234 and 235: 234 6 classical electrodynamics Cha
Page 236 and 237: 236 7 the story of the brain F I G
Page 238 and 239: 238 7 the story of the brain Vol. V
Page 240 and 241: 240 7 the story of the brain TA B L
Page 242 and 243: 242 7 the story of the brain consci
Page 244 and 245: 244 7 the story of the brain Ref. 2
Page 246 and 247: 246 7 the story of the brain F I G
Page 248 and 249: 248 7 the story of the brain Vol. I
Page 254 and 255: 254 7 the story of the brain ∗∗
Page 256 and 257:
Chapter 8 THOUGHT AND LANGUAGE Ref.
Page 258 and 259:
258 8 thought and language Challeng
Page 260 and 261:
260 8 thought and language Vol. VI,
Page 262 and 263:
262 8 thought and language F I G U
Page 264 and 265:
264 8 thought and language Challeng
Page 266 and 267:
266 8 thought and language Ref. 241
Page 268 and 269:
268 8 thought and language Vol. IV,
Page 270 and 271:
270 8 thought and language . . 0 1
Page 272 and 273:
272 8 thought and language Ref. 251
Page 274 and 275:
274 8 thought and language ⊳ Ever
Page 276 and 277:
276 8 thought and language F I G U
Page 278 and 279:
278 9 concepts, lies and patterns o
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
Page 314 and 315:
Page 316 and 317:
Page 318 and 319:
Page 320 and 321:
Chapter 10 CLASSICAL PHYSICS IN A N
Page 322 and 323:
322 10 classical physics in a nutsh
Page 324 and 325:
Page 326 and 327:
Page 328 and 329:
328 a units, measurements and const
Page 330 and 331:
Page 332 and 333:
Page 334 and 335:
Page 336 and 337:
Page 338 and 339:
Page 340 and 341:
Page 342 and 343:
342 challenge hints and solutions n
Page 344 and 345:
344 challenge hints and solutions R
Page 346 and 347:
346 challenge hints and solutions P
Page 348 and 349:
348 challenge hints and solutions v
Page 350 and 351:
350 challenge hints and solutions b
Page 352 and 353:
352 challenge hints and solutions f
Page 354 and 355:
354 challenge hints and solutions o
Page 356 and 357:
356 challenge hints and solutions 4
Page 358 and 359:
358 challenge hints and solutions C
Page 360 and 361:
360 challenge hints and solutions V
Page 362 and 363:
362 bibliography 10 Thiseffect hasf
Page 364 and 365:
364 bibliography 37 A discussionof
Page 366 and 367:
366 bibliography M.B. van der Mark
Page 368 and 369:
368 bibliography Vol. I, page 96 19
Page 370 and 371:
370 bibliography S.W. McCuskey, F.C
Page 372 and 373:
372 bibliography 119 A complete lis
Page 374 and 375:
374 bibliography F I G U R E 178 Th
Page 376 and 377:
376 bibliography in unserer Zeit33,
Page 378 and 379:
378 bibliography private communicat
Page 380 and 381:
380 bibliography success of structu
Page 382 and 383:
382 bibliography Vol. IV, page 135
Page 384 and 385:
384 bibliography and 304. 260 For a
Page 386 and 387:
386 bibliography Springer, 1996. wh
Page 388 and 389:
CREDITS Acknowledgements Many peopl
Page 390 and 391:
390 credits tute of Molecular Patho
Page 392 and 393:
392 credits scientific_photos.htm.O
Page 394 and 395:
NAME INDEX A Abbott A Abbott,T.A.37
Page 396 and 397:
396 name index D Democritus Democri
Page 398 and 399:
398 name index H Holmes Holmes, C.D
Page 400 and 401:
400 name index M Mohr Mohr, P.J. 38
Page 402 and 403:
402 name index S Sheldon Sheldon, E
Page 404 and 405:
404 name index Z Zybin Motion Mount
Page 406 and 407:
406 subject index A units 328 Aplys
Page 408 and 409:
408 subject index C classical class
Page 410 and 411:
410 subject index E Earth Earth age
Page 412 and 413:
412 subject index F finite finite 2
Page 414 and 415:
414 subject index I infrared photog
Page 416 and 417:
416 subject index L Lorentz Lorentz
Page 418 and 419:
418 subject index M motion motion a
Page 420 and 421:
420 subject index P physiologists p
Page 422 and 423:
422 subject index S Scarabeus Scara
Page 424 and 425:
424 subject index T table d’Unit
Page 426:
426 subject index W Wien’s Wien
show all

MOTION MOUNTAIN

Create successful ePaper yourself

Delete template?

Save as template?