Space Tech Glossary


Acceleration/deceleration factor; the amount a starship can accelerate or decelerate by, in units of 1000 km /
minute. For example, a starship with an ADF of 2 can increase its speed by 2000 km /minute in one minute.


Atoms are minute discrete units that make up matter. They are the building blocks of the ordinary matter that
we are most familiar with. A typical atom is tiny, about 10 000 000 000 (1E+10) atoms can fit side by side along
a one metre line. Atoms consist of a nucleus, containing most of the mass of the atom, which is made up of
particles called neutrons and protons. Electrons form 'layers' or 'shells' around the nucleus. The electrons carry
negative electric charge and so are attracted to the protons in the nucleus, which are positively charged, since
opposite electric charges attract. Opposite electric charges are pulled together by the exchange of photons
between them. These photons cannot be seen and so are called
virtual photons. Most of the atom is 'empty'
space (space is never empty!). More precisely, atoms consist of energy vibrations held together by light (virtual
photons). Ordinary matter, such as tables, chairs, walls, steel and your bodies, are made up of principally of
atoms. Atoms come in a variety of types, depending upon the numbers of neutrons, protons and electrons that
they contain. The number of protons determines the chemical element to which the atom belongs. For example,
an atom of iron has 26 protons, whilst an atom of hydrogen has only one. When you push against a wall, the
repulsion between the electrons in the atoms of your hand and the electrons in the atoms of the wall, causes
the wall to resist, since
like electric charges repel.

Beam battery

A weapon that fires energy or particle beams of some sort (whether lasers, proton beams, electron beams,
neutron beams or some other type). The term battery refers to several guns grouped together, whether or not
they may be mounted on a single turret.

Beam cannon

Specifically, a large energy beam weapon mounted on the bow of a starship.


Damage control rating. A measure of how easily a starship's computers, robots and crew and repair damage to
the ship out in space.


An electron is a negatively charged subatomic particle. Too small to be seen, it is the flow of electrons down a
wire that delivers electrical energy. Atoms consist of neutrons, protons and electrons (in addition to other
particles like quarks, gluons, photons and pions). The electron is thought to be a
fundamental particle, meaning
that it has no smaller constituents.

Emission line

A spectral emission line is a bright line seen in a star's spectrum. These lines are generally caused by the
absorption and re-emission of light of a specific band of wavelengths by material surrounding the star. This
material may be a shell of dust or gas thrown off from the star's surface, or an accretion disc or an adjacent
nebula, etc. Atoms in this material absorb a specific range of wavelengths from the star's light and then re-emit
it. It is this re-emitted light that is detected against the background light coming directly from the star itself.


Hull points. A measure of the maximum amount of damage a ships' hull can withstand before that ship ceases to

ICM (interceptor missile)

An interceptor missile is any small and automated missile defense system. Under computer control, the missiles
fire automatically in response to a small and fast moving potential threat, such as an incoming missile or fighter
with the aim of intercepting and neutralising the threat. Interceptor missiles are usually small since they need to
manoeuvre quickly and they only need a small warhead to neutralise small targets.


Laser stands for
light amplification by stimulated emission of radiation. Essentially a laser is a narrow beam of
high intensity light of a single wavelength (i.e. the light is of a single colour, it is monochromatic) that oscillates
in phase (the light is said to be coherent). Because the light is in-phase, monochromatic and focused into a
beam, lasers can travel very far before they become diffused or scattered and they can deliver a large amount
of energy in a small area of space and time.
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