Lever a place to stand, and I shall move the Earth with it' is a remark of Archimedes who formally stated the correct mathematical principle of levers (quoted by Pappus of Alexandria). It is assumed that in ancient Egypt, constructors used the lever to move and uplift obelisks weighing more than 100 tons. A lever is a beam connected to ground by a hinge, or pivot, called a fulcrum. The ideal lever does not dissipate or store energy, which means there is no friction in the hinge or bending in the beam. In this case, the power into the lever equals
World Enough and Time (Doctor Who) a share of 22%. The episode received 5.00 million views overall, and it received an Appreciation Index of 85, the joint highest score of Twelfth Doctor episodes along with "Dark Water" from the eighth series. "World Enough and Time" received overwhelmingly positive reviews from television critics, with many of them hailing it the best episode of the tenth series, but also criticizing the network for spoiling the cliffhanger early on. The episode currently holds an approval rating of 100% on Rotten Tomatoes, the site consensus reading, "World Enough and Time" sets up the conclusion of "Doctor Who"'s tenth season with