Physics Presentation Report
Megan Lee
Subpage: The law of lifters & Superconductivity

The law of lifters

A lifter is a kind of propulsion device that looks, feels & sounds more like the common conception of an antigravity machine.
It works on the principles of electromagnetism.
It consists of a triangular balsa wood frame with a ribbon of aluminium foil stretched around the outer edge.
It uses accelerated ions which have been removed from the air around them to produce a thrust.
However, the thrust produced by the lifter is not enough to lift its own power supply.

Superconductivity 

Superconductors are materials that when cooled sufficiently assume a state with zero electrical resistance.
Cooling down a material improves its electrical conductivity.
When a material makes the transition from normal to superconducting state, it actively excludes magnetic field from its exterior; this is called the Meissner effect.
In an ordinary conductor, heat makes the lattice of atoms in the material to vibrate & collide with the electrons, impeding their motion.
In a superconductor, resistance vanishes entirely.
The Meissner effect arises because superconductors expel any magnetic fields that try to pass through them.