Why Don't Perpetual Motion Machines Ever Work?

Three out of the four people below seriously pursued (at least for a time) the search for a working perpetual motion machine. Who's the odd man out?

• Bhaskara the learned

• Rube Goldberg

• Robert Boyle

• Leonardo da Vinci

Which of the following correctly describes a perpetual motion machine?

• A machine with infinite sources of energy

• A machine that re-uses all the energy it expends

• A machine with no zero velocity points

• A machine that can do work with no power source

Why will Bhaskara's wheel stop spinning?

• Flawed axle design

• Needs to be placed in a vacuum

• The center of mass is lower than the axis

• Mercury is too dense

Why won't the capillary bowl work?

• The capillary force is too weak

• It requires extra energy to free the droplet

• It doesn't work with modern-day tubes

• It could only work in zero-gravity conditions

Why does the second law of thermodynamics make perpetual motion machines impossible (to date)?

• Energy is always conserved

• Energy will always leech out of a system as heat

• There is no negative work

• Systems try to achieve equilibrium