The Entropy Accelerator is a tool added by Applied Energistics. It ages or cools any block it is used on. For example, it turns Water into Ice or Stone into Cobblestone. The Entropy Accelerator is the opposite of the Vibration Catalyst.
The Entropy Accelerator must be charged to be used. It can be charged in an ME Power Relay, or in any other compatible charging block (e.g. an Industrial Craft 2 MFE or Thermal Expansion Energetic Infuser)