A person living and working in an extreme environment must be protected from the dangers of rapid pressure changes, while adjusting to visual changes in perspective that arise when looking through various optical media, and establishing methods for reliable and accurate communications.
These issues can be divided into three basic groups:
Working with gases
Understanding the Boyle's Law, Dalton's Law of Partial Pressure, and the molecular behaviour of gases helps
scientists understand the medical hazards related to rapid changes in ambient gas pressure. It also helps medical
researchers work out strategies for working in environments where they must breathe unusual gases.
Optical phenomena
Much of an explorer's work is carried out looking though various optical media, such as water, lenses, and
thick windows. Serious problems can occur when optical effects create unforeseen changes in the apparent spatial position
of tools and objects in the explorer's workspace. In some cases unanticipated optical effects can render dangerous objects invisible.
Sounds
Changes in the acoustic properties of the working environment can make ordinary speech difficult to understand,
or even unintelligible. These problems are related to the acoustic resonance of the environment or of the human vocal cavity.
The Canadian designed diving suit (called the newtsuit) shown above incorporates the advantages of a strong, sealed container
(for long, deep dives), and flexibility
(for mobility and freedom of movement).
It allows divers to work up to eight hours at underwater pressures of about 2 MPa
(2,000 kPa) at depths over 300 m .
It is interesting to note that the design requirements for equipment used to live and work in space are almost identical to those needed for working in the ocean. In fact, in some ways, the design requirements for manned equipment for deep ocean diving are more demanding than those for space applications.


