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Nutation

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1135: 1212:. All other terms are much smaller; the next-largest, with a period of 183 days (0.5 year), has amplitudes 1.3″ and 0.6″ respectively. The periods of all terms larger than 0.0001″ (about as accurately as available technology can measure) lie between 5.5 and 6798 days; for some reason (as with ocean tidal periods) they seem to avoid the range from 34.8 to 91 days, so it is customary to split the nutation into long-period and short-period terms. The long-period terms are calculated and mentioned in the almanacs, while the additional correction due to the short-period terms is usually taken from a table. They can also be calculated from the 1230: 1095: 61: 821: 240:
Initially, however, there is no precession, and the upper part of the top falls sideways and downward, thereby tilting. This gives rise to an imbalance in torques that starts the precession. In falling, the top overshoots the amount of tilt at which it would precess steadily and then oscillates about
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is a movement of a rotational axis such that the first Euler angle is constant. Therefore it can be seen that the circular red arrow in the diagram indicates the combined effects of precession and nutation, while nutation in the absence of precession would only change the tilt from vertical (second
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is set at a tilt on a horizontal surface and spun rapidly, its rotational axis starts precessing about the vertical. After a short interval, the top settles into a motion in which each point on its rotation axis follows a circular path. The vertical force of gravity produces a horizontal torque
1181:. However, there are other significant periodic terms that must be accounted for depending upon the desired accuracy of the result. A mathematical description (set of equations) that represents nutation is called a "theory of nutation". In the theory, parameters are adjusted in a more or less 607: 618: 259:
with its tip fixed. (A symmetrical top is one with rotational symmetry, or more generally one in which two of the three principal moments of inertia are equal.) Initially, the effect of friction is ignored. The motion of the top can be described by three
936: 1309:, rapidly 'cycling' or 'changing' the 'shield nutation' is frequently mentioned as a means by which to delay the antagonist in their efforts to break through the defences and pillage the Enterprise or other spacecraft. 221: 1177:, which continuously change location relative to each other and thus cause nutation in Earth's axis. The largest component of Earth's nutation has a period of 18.6 years, the same as that of the precession of the 816:{\displaystyle E_{\text{r}}={\frac {1}{2}}I_{1}\left({\dot {\theta }}^{2}+{\dot {\phi }}^{2}\sin ^{2}(\theta )\right)+{\frac {1}{2}}I_{3}\left({\dot {\psi }}+{\dot {\phi }}\cos(\theta )\right)^{2}.} 478: 1004: 371: 53: 1051:
is zero. One of these is not related to a physical angle; the other two determine the upper and lower bounds on the tilt angle, between which the gyroscope oscillates.
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near the poles causes a change in Earth's nutation, as well as an 11° shift in the axial tilt and a change in Earth's orbit around the Sun.
1113: 602:{\displaystyle E_{\text{r}}={\frac {1}{2}}I_{1}\left(\omega _{1}^{2}+\omega _{2}^{2}\right)+{\frac {1}{2}}I_{3}\omega _{3}^{2}.} 1621: 1420: 173:
about the point of contact with the surface; the top rotates in the direction of this torque with an angular velocity
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The nutation of a planet occurs because the gravitational effects of other bodies cause the speed of its
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as well as constants that are related to the energy and the gravitational torque. The roots of
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and has the same period of 6798 days (18.61 years). It reaches plus or minus 17″ in
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do not give the best theory; one has to account for deformations of the Earth, including
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of the top about its own axis (third Euler angle). Thus, precession is the change in
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are solved for this system, it is found that the motion depends on two constants
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between the symmetry axis of the top and the vertical (second Euler angle); the
96: 1016: 469: 307: 134: 90: 931:{\displaystyle {\dot {\phi }}={\frac {b-a\cos(\theta )}{\sin ^{2}(\theta )}}.} 1615: 1297: 1190: 1074: 224: 30:
This article is about the concept in physics. For the term in astronomy, see
216:{\displaystyle {\boldsymbol {\tau }}=\mathbf {\Omega } \times \mathbf {L} ,} 1522: 1163: 261: 163: 279:
of the top about the vertical (first Euler angle); and the rotation angle
148:(a change in the first Euler angle) is sometimes referred to as nutation. 101: 'nodding, swaying') is a rocking, swaying, or nodding motion in the 1129: 1073:
to vary over time, so that the speed is not constant. English astronomer
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The earth's variable rotation : geophysical causes and consequences
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The principal term of nutation is due to the regression of the Moon's
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In the case of Earth, the principal sources of tidal force are the
1151: 128:. If it is not caused by forces external to the body, it is called 46: 271: 1541:
The Feynman Lectures on Physics Vol. I Ch. 20: Rotation in space
120:, or as an intended behaviour of a mechanism. In an appropriate 1038: 114: 110: 60: 1174: 52: 1587: 1479:. Federal Agency for Cartography and Geodesy. 2 April 2009 1476:
International Earth Rotation and Reference Systems Service
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harvnb error: no target: CITEREFFeynmanLeightonSands2011 (
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The rotation of the earth : a geophysical discussion
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Engineering dynamics : a comprehensive introduction
1550:(2d ed.). Reading, Mass.: Addison-Wesley Pub. Co. 941:
The tilt is determined by a differential equation for
1382: 961: 855: 621: 481: 329: 188: 1414: 846:). The rate of precession is related to the tilt by 450:axes. Since we are taking a symmetric top, we have 1589: 1569:(Digitally printed 1st pbk. ed.). Cambridge: 1471:"Resolution 83 on non-rigid Earth nutation theory" 998: 930: 815: 601: 365: 237:is the instantaneous angular momentum of the top. 215: 105:of a largely axially symmetric object, such as a 1613: 1588:Munk, Walter H.; MacDonald, Gordon J.F. (1975). 1296:, the near-simultaneous detonation of two super- 144:Euler angle). However, in spacecraft dynamics, 1185:method to obtain the best fit to data. Simple 34:. For the term in mechanical engineering, see 124:it can be defined as a change in the second 1439: 1427: 1383:Kasdin, N. Jeremy; Paley, Derek A. (2010). 1258:. Unsourced material may be challenged and 1102:It has been suggested that this section be 1158:that are defined by the Earth's tilt (the 382:axis is the axis of symmetry, the top has 1545: 1457: 1445: 1433: 1410: 1408: 1278:Learn how and when to remove this message 1341: 1339: 1133: 320:relative to the plane of the support is 59: 51: 1564: 1523:"NeoProgrammics - Science Computations" 241:this level. This oscillation is called 190: 14: 1614: 1405: 1345: 1138:Yearly changes in the location of the 612:In terms of the Euler angles, this is 1336: 1219: 1106:out into another article titled 252:can be explored using the model of a 1256:adding citations to reliable sources 1223: 1216:according to IAU 2000B methodology. 1088: 248:The physics of nutation in tops and 1498:"Basics of Space Flight, Chapter 2" 999:{\displaystyle {\dot {u}}^{2}=f(u)} 366:{\displaystyle V=Mgl\cos(\theta ).} 24: 1415:Feynman, Leighton & Sands 2011 151: 25: 1643: 376:In a coordinate system where the 1228: 1093: 206: 198: 1515: 1490: 1463: 1451: 1376: 1306:Star Trek: The Next Generation 993: 987: 919: 913: 895: 889: 796: 790: 720: 714: 357: 351: 291:and nutation is the change in 56:Nutation of a sphere animation 27:Wobble of the axis of rotation 13: 1: 1533: 1293:The Day the Earth Caught Fire 1150:of Earth with respect to the 1622:Rotation in three dimensions 1354:(2nd ed.). Cambridge : 1146:Nutation subtly changes the 1054: 7: 1546:Goldstein, Herbert (1980). 1312: 1077:discovered the nutation of 1041:of the angles at which the 1019:that depends on parameters 10: 1648: 1571:Cambridge University Press 1389:Princeton University Press 1356:Cambridge University Press 1350:Fundamentals of Geophysics 1290:In the 1961 disaster film 1127: 1058: 316:from the pivot point, its 155: 44: 29: 1502:Jet Propulsion Laboratory 1156:major circles of latitude 40:Nutation (disambiguation) 1346:Lowrie, William (2007). 1329: 1142:near a highway in Mexico 1084: 1065:Perturbation (astronomy) 828:Euler–Lagrange equations 179:such that at any moment 82:in obliquity of a planet 45:Not to be confused with 318:gravitational potential 1565:Lambeck, Kurt (2005). 1143: 1000: 932: 817: 603: 367: 217: 95: 83: 57: 38:. For other uses, see 36:Nutation (engineering) 1504:/NASA. 28 August 2013 1137: 1128:Further information: 1061:Astronomical nutation 1001: 933: 818: 604: 368: 218: 156:Further information: 63: 55: 32:Astronomical nutation 1391:. pp. 526–527. 1252:improve this section 1195:core–mantle boundary 1179:Moon's orbital nodes 1154:plane, shifting the 959: 853: 619: 479: 327: 300:If the top has mass 186: 1548:Classical mechanics 1387:. Princeton, N.J.: 1193:and changes in the 1191:mantle inelasticity 1187:rigid body dynamics 842:(each related to a 595: 552: 534: 158:Rigid body dynamics 1460:, pp. 213–217 1220:In popular culture 1208:and 9.2″ in 1144: 996: 928: 844:constant of motion 813: 599: 581: 538: 520: 410:moments of inertia 384:angular velocities 363: 213: 84: 58: 1288: 1287: 1280: 1126: 1125: 1121: 972: 923: 865: 781: 766: 739: 692: 670: 643: 629: 569: 503: 489: 310:is at a distance 264:: the tilt angle 16:(Redirected from 1639: 1607: 1595: 1584: 1561: 1527: 1526: 1519: 1513: 1512: 1510: 1509: 1494: 1488: 1487: 1485: 1484: 1467: 1461: 1455: 1449: 1443: 1437: 1431: 1425: 1424: 1412: 1403: 1402: 1380: 1374: 1373: 1353: 1343: 1283: 1276: 1272: 1269: 1263: 1232: 1224: 1160:tropical circles 1140:Tropic of Cancer 1117: 1109:Earth's nutation 1097: 1096: 1089: 1071:axial precession 1050: 1036: 1030: 1024: 1017:cubic polynomial 1014: 1005: 1003: 1002: 997: 980: 979: 974: 973: 965: 951: 937: 935: 934: 929: 924: 922: 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2020) 1101: 1099: 1092: 1086: 1083: 1056: 1053: 1043:rate of change 1007: 1006: 995: 992: 989: 986: 983: 978: 971: 968: 939: 938: 927: 921: 918: 915: 912: 907: 903: 897: 894: 891: 888: 885: 882: 879: 876: 870: 864: 861: 824: 823: 812: 807: 802: 798: 795: 792: 789: 786: 780: 777: 771: 765: 762: 755: 748: 744: 738: 735: 730: 726: 722: 719: 716: 713: 708: 704: 698: 691: 688: 681: 676: 669: 666: 658: 652: 648: 642: 639: 634: 625: 610: 609: 598: 593: 588: 584: 578: 574: 568: 565: 560: 556: 550: 545: 541: 537: 532: 527: 523: 518: 512: 508: 502: 499: 494: 485: 470:kinetic energy 464: 455: 430: 423: 416: 404: 397: 390: 374: 373: 362: 359: 356: 353: 350: 347: 344: 341: 338: 335: 332: 308:center of mass 229: 228: 212: 208: 204: 200: 196: 192: 153: 150: 80: Nutation 76: 70: 68: Rotation 64: 26: 9: 6: 4: 3: 2: 1644: 1633: 1630: 1628: 1625: 1623: 1620: 1619: 1617: 1605: 1603:9780521207782 1599: 1594: 1593: 1586: 1582: 1580:9780521673303 1576: 1572: 1568: 1563: 1559: 1553: 1549: 1544: 1542: 1539: 1538: 1524: 1518: 1503: 1499: 1493: 1478: 1477: 1472: 1466: 1459: 1454: 1448:, p. 217 1447: 1442: 1436:, p. 220 1435: 1430: 1422: 1416: 1411: 1409: 1400: 1398:9780691135373 1394: 1390: 1386: 1379: 1371: 1369:9780521675963 1365: 1361: 1357: 1352: 1351: 1342: 1340: 1335: 1325: 1322: 1320: 1317: 1316: 1310: 1308: 1307: 1301: 1299: 1295: 1294: 1282: 1279: 1271: 1268:November 2022 1261: 1257: 1253: 1247: 1246: 1242: 1237:This section 1235: 1231: 1226: 1225: 1217: 1215: 1211: 1207: 1203: 1198: 1196: 1192: 1188: 1184: 1180: 1176: 1172: 1167: 1165: 1164:polar circles 1161: 1157: 1153: 1149: 1141: 1136: 1131: 1120: 1115: 1111: 1110: 1105: 1100: 1091: 1090: 1082: 1080: 1076: 1075:James Bradley 1072: 1066: 1062: 1052: 1049: 1044: 1040: 1035: 1029: 1023: 1018: 1013: 990: 984: 981: 976: 969: 966: 955: 954: 953: 949: 945: 925: 916: 910: 905: 901: 892: 886: 883: 880: 877: 874: 868: 862: 859: 849: 848: 847: 845: 840: 834: 829: 810: 805: 800: 793: 787: 784: 778: 775: 769: 763: 760: 753: 746: 742: 736: 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Retrieved 1492: 1481:. Retrieved 1474: 1465: 1453: 1441: 1429: 1384: 1378: 1349: 1304: 1302: 1291: 1289: 1274: 1265: 1250:Please help 1238: 1199: 1182: 1168: 1145: 1118: 1107: 1079:Earth's axis 1068: 1047: 1033: 1027: 1021: 1011: 1008: 952:of the form 947: 943: 940: 838: 832: 825: 611: 461: 452: 446: 440: 436: 427: 420: 413: 401: 394: 387: 378: 375: 312: 302: 299: 293: 287: 281: 275: 266: 262:Euler angles 253: 247: 242: 239: 233: 230: 175: 169: 161: 140: 133: 129: 94: 86: 85: 1632:Geodynamics 1358:. pp.  1130:Geodynamics 126:Euler angle 1627:Astrometry 1616:Categories 1557:0201029189 1534:References 1508:2015-03-26 1483:2012-08-06 1214:Julian day 1202:nodal line 1148:axial tilt 434:about the 250:gyroscopes 146:precession 89:(from 1319:Libration 1239:does not 1210:obliquity 1206:longitude 1081:in 1728. 1055:Astronomy 970:˙ 917:θ 911:⁡ 893:θ 887:⁡ 878:− 863:˙ 860:ϕ 794:θ 788:⁡ 779:˙ 776:ϕ 764:˙ 761:ψ 718:θ 712:⁡ 690:˙ 687:ϕ 668:˙ 665:θ 583:ω 540:ω 522:ω 355:θ 349:⁡ 203:× 199:Ω 191:τ 118:in flight 107:gyroscope 1324:Teetotum 1313:See also 1162:and the 1152:ecliptic 306:and its 243:nutation 223:(vector 137:nutation 87:Nutation 47:nunation 1260:removed 1245:sources 1114:Discuss 1039:cosines 826:If the 272:azimuth 97:nūtātiō 1600:  1577:  1554:  1395:  1366:  1183:ad hoc 1048:θ 1009:where 948:θ 946:= cos( 468:. 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Index

Free nutation
Astronomical nutation
Nutation (engineering)
Nutation (disambiguation)
nunation


Latin
nūtātiō
axis of rotation
gyroscope
planet
bullet
in flight
reference frame
Euler angle
Euler
precession
Rigid body dynamics
top
cross product
gyroscopes
symmetrical top
Euler angles
azimuth
center of mass
gravitational potential
angular velocities
moments of inertia
kinetic energy

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