Rotational Gravity on Babylon 5

Prior to the formation of the Interstellar Alliance, the Earth Alliance did not have the means to artificially create gravity.  To simulate gravity on their space stations and starships, the Earth Alliance used rotating sections.  Most of the Babylon 5 station rotates to simulate gravity for its inhabitants.
Babylon 5's rotating sections complete one revolution about every 53 seconds.  If we know the rate of rotation and the diameter of one of the station's "decks", we can determine how much simulated gravity a person standing on the deck will experience.

The following formulas show how to determine the acceleration of simulated gravity:

a = v2 / r
a = 4?2r / T2
In the formulas, r represents the distance from the station's axis to the deck, v represents the tangential velocity at the deck, T represents the time required for the station to complete one revolution, and a represents the acceleration experienced at the deck.  Knowing any two of these values, we can solve for the third.  For instance, we can determine the gravity someone would experience if they were standing against the outer hull of the station's largest section.
T = 53
r = 475 m (one half the section's diameter of 950 m)
a = 6.6 m/s2 = 0.7 G's

Incident Examination: The Fall of Night

In the episode The Fall of Night, Sheridan leapt from a rail car near the station's axis to escape a bomb placed by a Centauri assassin.  He was not in danger because he was accelerating toward the "ground" of the habitat section; since he wasn't in contact with the station's structure, he wasn't experiencing any acceleration.  He was in danger because the "ground" was moving at 60 miles per hour relative to his falling body.

60 MPH converts to about 27 meters/second.  Given the station's observed rotation rate of 1.13 rpm, the "ground" at her location must be approximately 228 meters from the station's axis.  The "gravity" on the deck there would be approximately 0.33 G's.

Gravity on the station will vary considerably depending on the distance from the station's axis, but it will always be less than normal Earth gravity.  The station could potentially benefit from a greater rate of rotation, since most humans can tolerate a rotation rate of 2 rpm without suffering from motion sickness, and the resulting increase in simulated gravity would prevent muscle atrophy and other symptoms of prolonged exposure to sub-normal gravity in the station's inhabitants.

Rotational Gravity Calculator


Observed Rotation The Fall of Night
Rotation period (T) seconds Tangent velocity (v) m/s
Radius (r) m Radius (r) m
Acceleration (a) m/s2 Acceleration (a) m/s2
Gravity G's Gravity G's


Resources