Galactic Barrier

• Barrier of negative energy surrounding the Milky Way galaxy, source unknown
• No known types of subspace transmissions able to penetrate the barrier (TOS: "By Any Other Name")
• Invisible at distance
  • Only visible when in proximity, manifesting the appearance of a wide purple/pink band of energy ahead of travel (TOS: "Where No Man Has Gone Before")
• Early sensors unable to detect barrier
  • Starfleet sensors of 2265 unable to, but later upgrades functioned properly (TOS: "Where No Man Has Gone Before", "By Any Other Name")
• Incredibly dangerous to pass through
  • Requires specially designed shielding and engine technologies to be able to leave or enter the Barrier (TOS: "Where No Man Has Gone Before", "By Any Other Name")
  • Proximity results in extreme interaction with individuals of high esper or telepathic potential (TOS: "Where No Man Has Gone Before")
    • Individuals with low esper rating show no effect (TOS: "Where No Man Has Gone Before", "By Any Other Name", "Is There in Truth no Beauty?")
    • Individuals with moderately high esper rating die as a result of psionic overload (TOS: "Where No Man Has Gone Before")
    • Individuals with extremely high esper rating gain rapidly accelerating telekinetic and telepathic abilities (TOS: "Where No Man Has Gone Before")