#### Milestone Year

### 1954

#### WEIZAC, the first computer in Israel

The WEIZAC (Weizmann Automatic Computer) was the first computer in Israel,
and one of the first large-scale, stored-program, electronic computers
in the world.

It was built at the Weizmann Institute during 1954-1955,
based on the Institute for Advanced Study (IAS) architecture
developed by John von Neumann.
The WEIZAC was operational until December 29, 1963,
and has been superseded by the GOLEM.

WEIZAC was used for mathematical research,
such as solving problems related to the computation of ocean tides;
this entailed complex calculations which
could not reasonably be performed manually.
The calculations carried out using WEIZAC took hundreds of computer hours,
and enabled scientists to chart maps giving a very close approximation
of high and low tide fluctuations throughout the world.
As a result, the Weizmann researchers predicted the precise location
of an amphidromic point (at which high and low tides never occur)
in the southern Atlantic. Measurements performed in the wake
of the discovery confirmed the existence and location of this point.

In another research study, Weizmann scientists used WEIZAC to
calculate the spectrum of a helium atom
(which involves three particles: the nucleus and
the two electrons moving around it).
Solving the dynamic relationships between three bodies
is considered a highly complex mathematical task,
and despite the development of modern, powerful computers,
we still have no general, complete solution to such problems.
However, the problem of the helium atom has been solved completely
and yielded results that were experimentally confirmed
by the Brookhaven National Laboratory in the United States.

In other projects, WEIZAC was used to carry out calculations to examine
various theoretical models of the internal structure of the Earth,
taking into account its different strata.
These studies were based on calculations of shock wave propagation
through different strata; comparisons with actual measurements
were carried out after the occurrence of several earthquakes
around the world.