I googled this phrase, and the only place it occurs on the entire Internet is in a Wikipedia article on Schleifenquantengravitation ("Loop quantum gravity"), or in pages quoting that article.
As far as I can tell (knowing little about German and even less about quantum physics), it should be translated there as "The network is the space," and it seems to be talking about a mathematical model of space as a network of nodes.
Makes me wonder if Duolingo gets some of it phrases from Wikipedia articles. I can't blame anyone for being frustrated with this one.
Interesting - because that was my first thought...I also know NOTHING about quantum physics! But I was thinking of "Raum" as "Weltraum"...and it does seem at times that the internet can (in an exaggerated way) be compared to the universe! I thought this was some kind of symbolic comparison. But I also like the idea that the internet can act as a room...I guess like a "chat room"...?
Why not "The network is the space itself"? Is it gramatically incorrect?