The Aetheric Sargasso
Regarded as the Fifth Classical Element (Earth, Air, Fire, Water and Aether) it allows for the transmission of matter and energy between alternate realities. The Aether lies thinly in the Sea of Shards, appearing as wafting clouds of mist and vapor. This is only the surface of the Shard Sea, as the Mists are propelled and disturbed by other currents. These less-visible currents are fluctuations of energy between the fractured Realms. They can leave Sargassos in their wake. Savvy Aether Sailors wear Aetheric Goggles to detect the more subtle changes in the Aether Tides. Some claim to see the Aether Tides with unaided eyes, but that gift is rare indeed.
Bounding the Sea of Shards is the Aetheric Ocean proper. There the Aether Tides flow more smoothly. Sometimes warm, sometimes cold, with only the occasional fragment of a broken world.
Ref. : http://en.wikipedia.org/wiki/Aether_theories