A wormhole is usually held open by negative energy, like in the Casimir effect. But if a gravitational wave passes through, the memory of that event alters its structure — making it more stable and outwardly resembling a black hole's shadow. Telescopes may already be seeing such objects.
🎯 The Casimir effect was predicted by Hendrik Casimir in 1948 over a cup of coffee while discussing the properties of the vacuum.
🎬 The wormhole as a portal is familiar from the movie Interstellar, where the scientific basis was laid by [scientist:Kip Thorne]Kip Thorne[/scientist].