"Space has three dimensions. We live
in those three dimensions of length, breadth, and thickness. This is
called the space continuum.

"There is also a three dimensional time continuum. This also has length,
which is past-present-future. In addition it has width and breadth,
which are approximated by the idea of simultaneity to a certain extent.
This is not, however, the simultaneity of events co-existent in our one,
three-dimensional space. All events we can be aware of are in one point
in the time continuum, which moves along a single time line.

"Since there are only three dimensions of space, all things must be in
our space. It is the time co-ordinates that determine whether we are
aware of something or not. At this very moment there is an infinity of
universes all occupying the same space, but each in a different position
in time. They are existing now, but separated from us in a direction at
right angles to the universal time stream.

"Mathematically, these other universes are expressed in co-ordinates
that have the square root of a minus one as a coefficient. Also
mathematically, these universes are imaginary, but not in the
non-mathematical, mythical sense. They are just as real as ours, but
relatively imaginary or relatively non-existent.

"All this has been known by others. They have also known that to make an
imaginary value real it is only necessary to multiply it by the square
root of a minus one. Then it becomes real. This fact became the entering
wedge into the principal that enabled me to succeed in bridging the
abyss of right angle time travel.

"As you know, many years ago the secret of single dimension time travel
was solved. However, it would not answer our problem. Though it is true
time travel, it amounts to nothing more than perfect stasis for
controlled periods, and if destruction hits the space the time traveller
is in, he is as vulnerable as he would be if not travelling. In order to
escape that it is necessary to step over, so to speak, into one of the
imaginary universes at right angles to us in the time continuum and
travel forward there.

"So, all I had to do was discover some principal for multiplying a
sector of space by the square root of a minus one. As you know, I did
that. Then I discovered that there are gaps, so that it was impossible
to discover another universe co-existent in space, without determining
the basic equation of the time curve.

"As everyone knows, both time a