Decades: 1210s 1220s 1230s 1240s 1250s - 1260s - 1270s 1280s 1290s 1300s 1310s
Years: 1258 1259 1260 1261 1262 - 1263 - 1264 1265 1266 1267 1268
Births
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... accelerate or brake the spinning gyroscope, with a maximum effect when the axis starts "rolling" inside the groove. (Compare with graphic below.) Since this friction force ...