Light Speed

The Speed of Light, or Light Speed, is the maximum possible speed in the N-space universe, and is a constant speed of 299,792.458 km/s (often expressed as 3×10⁸ m/s) in vacuum at which any particle of zero rest-mass (such as the photon) will automatically propagate.

• This value is commonly abbreviated as "c".

Description (Specifications)

The Speed of light is an upper-limiting speed for all particles or physical objects in the Universe under the conventional laws of physics as defined by Einsteinian geometrodynamical spacetime.

• Exceeding Light Speed (FTL) requires a way to break or modify the conventional physical laws of the universe.

Background: Special Relativity

Under special relativity, a number of principles and theories are optimally studied in order to fully grasp this subject.

Mass-Energy Equivalency Principle

According to the mass-energy equivalency principle arising from the Special Theory of Relativity, the energy of any particle may be described by the equation:

• E = mc²

where:

m = mass

c = speed of light

Thus, any particle has an intrinsic "rest-energy" (E₀) as defined by its mass while motionless (its "rest-mass", m₀), independent of any internal thermal properties or kinetic energy it may acquire due to motion, as described by the equation:

• E₀ = m₀c².

By extension, an object has a "kinetic mass" (m_k) due to its kinetic energy (E_k) while in motion relative to an independent observer that is in addition to its rest mass (m₀):

• E_k = m_kc²

or

• m_k = E_k / c²

Thus, as an object accelerates relative to an independent observer, its total mass (m_tot), also known as "relativistic mass", relative to that observer increases:

• m_tot = m₀ + m_k = (E₀ / c²) + (E_k / c²)

The "total energy" (E_tot) of a particle is described as the sum of its rest energy (E₀) and its kinetic energy (E_k) by the following equation:

• E_tot = E₀ + E_k = m_oc² / (1 - v²/c²)^½

and is dependent upon its velocity relative to the one observing.

As a consequence, a constant force applied to a particle will produce a continually decreasing acceleration as its mass increases as a function of velocity, implying that in fact F ≠ m₀a, but rather F ≈ m₀a for small enough values of velocity. Thus, due to the equivalency principle of mass and energy, as m → ∞ with increasing velocity, a → 0, asymptotically approaching a maximum velocity. This limiting velocity is the maximum speed of the universe, and is also the constant speed at which zero-rest mass particles (such as photons and gravitons) propagate, and is colloquially known as the speed of light as a result. It is thus impossible to accelerate an object with non-zero rest mass to the speed of light in a finite amount of time (or alternatively, it would require an infinite force (and/or an infinite amount of energy) to produce the acceleration necessary to accelerate a non-zero rest mass particle to the speed of light).

Lorentz-contraction and Time-dilation

No information currently available.

• Speed of light constant is the same in all inertial reference frames, independent of observer motion.
• Time dilation: t = t_o / (1 - v²/c²)^½

Effects of time dilation become a consideration above ~ 0.10c.

Effects of time dilation become significant above ~ 0.90c.

• Lorentz-contraction: l = l_o × (1 - v²/c²)^½
• Simultaneity of events is a local, not absolute phenomenon.

Light speed as a distance metric

Due to the vast distances involved in interstellar measurements, it is often convenient to use the very large constant value of the speed of light in vacuum as the basis for a distance metric. As light travels at a constant speed of ~ 3×10⁵ km/s in vacuum, the distance that light will travel in one year can be calculated to be approximately 9.47×10¹² km. This distance is used as a common metric for interstellar distances, and is known as a lightyear. Shorter distances are also often defined in a similar manner, and include such distance metrics as the light-week, light-day, light-hour, light-minute, and light-second.

A related metric for measuring interstellar distances is the parsec, an abbreviation of "paralax second". A parsec is defined as the distance at which a shift in the position of an observer of 1.0 astronomical unit, or AU, will produce a shift in the observed position of a distant object of one second of arc. A parsec is calculated to be roughly 3.26 lightyears in distance, multiples of which also happen to be close to the maximum Jumpspace traverse distances of the standard Jump Drive.

History & Background (Dossier)

No information currently available.

• Mention of FTL and NAFAL
• Any relations or implications to the OTU.
• Talk of the major races.

References & Contributors (Sources)

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• TBD
• Author & Contributor: Wayne
• Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science