#### Terms

** Copenhagen Institute ** - · One of the leading centers of physics research, headed
by Niels Bohr. Heisenberg studied here and served as Bohr's assistant, during
which time he did some of his crucial work in formulating quantum
mechanics.

**Core model ** - · Heisenberg's first attempt at explaining troublesome
phenomena in the atom. While he succeeded in reconciling the Zeeman effect,
in doing so he also discarded other established principles of quantum
theory.

**Determinism ** - · The belief, championed most famously by Einstein,
that science would ultimately be able to predict all behavior once
all the forces of nature were understood. Heisenberg's uncertainty principle
directly opposed this, as it undermined the validity of causality.

** Quantum mechanics ** - · The quantified study of the inner workings of the atom,
based on the principles of quantum theory.

**Quantum theory ** - · A theory that addresses the duality of matter and energy,
which have the properties of both particles and waves. Specific
theories such as Heisenberg's uncertainty principle contribute
to this broader scheme.

**Uncertainty
principle ** - · Formulated by Heisenberg in 1927, this principle
states that the velocity and position of an electron can never
both be exactly determined, since the act of measurement necessarily
disturbs the conditions.

** Zeeman principle** - · Heisenberg's revision of one of Bohr's quantum postulates.
He recognized that certain relationships that held only in classical mechanics
would have to be replaced. He used this principle to refine the
core model and thereby reconciled many of the current puzzles,
earning himself an invitation to Copenhagen.

#### People

** Niels Bohr ** - Perhaps Heisenberg's most influential mentor, he headed
the Copenhagen Institute and helped to refine the work of Heisenberg,
among many other young scientists.

**Max Born ** - Another of Heisenberg's early mentors, he taught physics
at Göttingen. Later on, he would recognize the matrix patterns
of Heisenberg's work and help to establish quantum mechanics.

**Albert Einstein ** - The most famous twentieth-century physicist, who differed
from Heisenberg in two fundamental ways. First, Einstein never
accepted uncertainty and believed that determinism was attainable.
Second, he saw no justification for the separation of science and
politics, and therefore used his international fame to campaign against
the Nazis.

** Annie Heisenberg ** - Heisenberg's mother.

** August
Heisenberg ** - Heisenberg's father.

** Wolfgang Pauli ** - A physicist who came of age around the same time
as Heisenberg and would remain a close collaborator throughout
their careers.

** Max Planck ** - One of Heisenberg's precursors in quantum theory, he
would later collaborate with Heisenberg in attempts to save German
physics at the onset of the Nazi regime. Planck encouraged Heisenberg
not to resign his position and to instead wait out the Nazi reign
to rebuild Germany after its inevitable defeat.

**Erwin
Schrödinger ** - He showed how electron
behavior could be understood in terms of waves. Schrödinger's theory yielded
the same mathematical results as Heisenberg's quantum mechanics,
but their pictures of the atom differed fundamentally.

**Elisabeth Schumacher** - Heisenberg's wife.

**Ernest Sommerfeld ** - Head of theoretical physics at Munich, he was Heisenberg's
first mentor in science. Sommerfeld also tried to appoint Heisenberg
as his successor, but was thwarted by Heisenberg's Nazi opponents.

**Willy Wien ** - The Munich professor who nearly failed Heisenberg during
his oral examinations because he failed to demonstrate competence
in experimental physics.