Are Gravitational Waves Indeed Detectable?

Whereas LIGO experimenters are being hailed for their claiming to have observed the Einsteinian phenomenon by green-eyed eggheads worldwide, a handful of right-minded heretics still keeps itself occupied with the question in the title. Billions of light years away from a source generating them, their wavefronts must be considered planar, right? As those plane waves distort spacetime homogeneously and together with the tools, intended to capture them yet inherent in that very continuum, then how can they be detected?

Hyperborean Bypass to EU Refuge

While the Horde suffers losses storming Fortress Europe, the most inventive and frost-resistant asylum seekers have already discovered a secure and 100 percent reliable route to the E.U. - thru Russia's North. The would-be refugees enter Russia with tourist visas, and then arrive in the town of Nickel (located above the Arctic Circle), where - provided they can brave the elements - smugglers take them across the poorly policed Norwegian border for €500. Although Norway isn't a member of the Union, the country belongs to the Schengen area, so the undocumented newcomers may continue their journey passport-free to wherever they wish.
That's about to change, however, as the Norwegian authorities began sending the unwanteds back to Russia on January 20, 2016.