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Myths

Myths about simple machines

Eight common ideas, checked against the sources.

How this site works. Every fact is in our own words and linked to its source, beside it. Where good sources disagree, we show each version in a “Sources differ” box.

  1. MythArchimedes said “Give me a place to stand and I will move the Earth”.

    FactBritannica calls the story that he said “Give me a place to stand and I will move the Earth” apocryphal: not reliably recorded. Britannica The famous wording, “Give me a place to stand and with a lever I will move the whole world”, is from John Tzetzes, writing in the 12th century AD. Rorres, NYU

  2. MythA good machine gives you more work out than you put in.

    FactA machine cannot do more work than the energy put into it, so energy is still conserved. OpenStax Ignoring friction, the work you put into a machine equals the work you get out. US Navy

  3. MythA ramp makes the job smaller.

    FactIt takes the same amount of work, but less force, to move an object up a ramp than to lift it straight up. Science Trek

  4. MythEveryone agrees there are exactly six simple machines.

    FactBritannica’s own articles on the pulley and the wedge call each of them one of “the five simple machines”, a list without the inclined plane. Britannica A US Navy training manual also counts six, but a different six: the lever, the block, the wheel and axle, the inclined plane, the screw and the gear. US Navy

  5. MythOne pulley halves the effort.

    FactA single fixed pulley has a mechanical advantage of 1: it doesn’t reduce the force, it changes its direction. OpenStax

  6. MythHolding something heavy still is hard work, so it must be work.

    FactHolding a heavy object still, however tiring, does no work in the physics sense. Britannica

  7. MythLevers always make things easier to lift.

    FactA shovel is a lever with a mechanical advantage of less than one: it gives up force to gain speed and distance at the blade. OpenStax In a third-class lever the effort is between the fulcrum and the load: tweezers, tongs and fishing rods. BBC Bitesize

  8. MythArchimedes definitely invented the screw.

    FactArchytas of Tarentum, in the 5th century BC, is the alleged inventor of the screw. Britannica The water screw is usually credited to Archimedes, but there is evidence of a similar device in Egypt earlier. Britannica