Log Entry:
*Captain's Log, Stardate 46125.3. Starfleet has dispatched two science vessels to study the Dyson Sphere while we proceed to Starbase 55.

The footage of the unmanned U.S.S. Enterprise NCC-1701 bridge was taken from the Star Trek episode "This Side of Paradise (01x24)."

On the holodeck bridge of the old Enterprise, Picard tells Scotty that a U.S.S. Enterprise is in the Starfleet Museum. It's not specified which Enterprise it was, since both Kirk's and Archer's Enterprises were retired from service, but, from the context, one would be led to assume it was the one Scotty had created on the holodeck, if it wasn't both.

The Dyson Sphere is an actual concept that pre-dated this episode by more than 30 years, and is named after pioneering theoretical physicist Freeman Dyson. Dyson himself acknowledges that the overall notion actually dates back to some SF stories in pulps of the late 1930s, but he was the first one to do a substantial theoretical analysis of it.

The Dyson Sphere itself is part of a class whimsically called Big Dumb Objects, or more formally, a megastructure, which includes the far more famous Ringworld (aka "Niven Ring") as well as the ring-shaped structure used in the FPS game Halo.

In-Joke: Data's line regarding the Aldebaranian whiskey of "It's... green" harks back to the ST:TOS episode By Any Other Name (02x22) when Scotty describes an unidentified bottle of liquor using the same words.

Long time fans of Star Trek will notice that Scotty at different times refers to events from the ST:TOS episodes The Naked Time (01x04), Wolf in the Fold (02x14) and Elaan of Troyius (03x13)."

Geordi: So this alien space baby. which is about the size of a four story building, really thought The Enterprise was its mother...

Geordi is relating to Scotty the events behind Galaxy's Child (04x16).