# Quantum Mechanics & Particle Physics

## Quantum Physics vs Newtonian Physics?

Classical physics does not suffice to explain the experimental observations of a whole range of natural phenomena.  From the atomic structure and spectral lines, to the shape of the blackbody spectrum, the photoelectric effect or the specific heat of solids.

The 18th century’s Scientific Revolution brings many advances in the domain of physical sciences.  Following in Newton’s footsteps, most scientists agree on the assumption that the Universe is governed by strict natural laws that can be discovered and formalised by means of scientific observation and experiment.  This point of view is known as ‘determinism’ and appears to preclude the possibility of free will.  Theoretically at least, if the Universe, and any individual in it, is governed by strict and universal laws, any individual’s behaviour can actually be predicted, based on sufficient knowledge of the circumstances obtained prior to that individual’s behaviour.  Or can it?

## Schrödinger and his Very Unfortunate Cat

The advent of Quantum Mechanics provides the modern natural philosopher with new alternatives to those strictly bound possibilities, and proposes the model of a Universe that follows general rules, yet somehow never has a predetermined future.

Since 1911, experiments prove that the distance between nuclear particles constituting atomic bodies, including our own, are space-like empty.  In fact, 100 times emptier than the volume of the Solar System!  Everything that we know around us like matter, energy, life, the Universe and everything… is made up of empty space.

Sounds crazy, right?

1933, Erwin Schrödinger’s new theory of Quantum Mechanics proposes to resolve the mysteries of the atomic structure and reveal an uncertain Universe…

Schrödinger’s time-dependent equation is

#### $i \hbar \frac{\partial}{\partial t} \Psi = \hat {H} \Psi$$i \hbar \frac{\partial}{\partial t} \Psi = \hat {H} \Psi$

Schrödinger’s time-independent equation is

#### $E \Psi = \hat {H} \Psi$$E \Psi = \hat {H} \Psi$

Each one a perplexing quantum mechanical wave functions.  But is there more to it than just a mathematical function?  From Imperial College (London), Dr Daniel Mortlock explains here in this short PhysicsWorld video.

So, what about Kitty then?  Martin Archer gives his take here in this other short PhysicsWorld video.