Wormholes: Tunnels in Spacetime — Between Hypothetical Bridges and Real Physics

This paper examines wormholes — hypothetical tunnels in spacetime connecting distant regions. It traces the history of their discovery: from the first solutions of general relativity equations (Flamm, 1916; Einstein and Rosen, 1935) to the work of Thorne and Morris (1988), which showed that with exotic matter (negative energy) a wormhole could be stable and traversable. The name “wormhole” was coined by John Wheeler in 1957, comparing the object to a worm burrowing a short path through an apple. In Russian, both “chervotochina” (direct translation) and “krotovaya nora” (mole burrow) are used; the latter is chosen here as the main term. The anatomy of a wormhole includes two mouths, a throat, and a proper length. The main obstacle to wormhole existence is the need for exotic matter with negative energy density. Quantum inequalities limit the amount of such matter: the larger the negative energy, the shorter its lifetime. Therefore, macroscopic stable wormholes are most likely impossible. Current searches include gravitational lensing analysis (distinguishing a wormhole from a black hole has not yet succeeded) and the gravitational‑wave candidate GW190521, which some interpret as echoes from a collapsing wormhole. The paper illustrates the principle of the choice of the level of description (G): at the classical GR level (G₁), wormholes are unstable; taking quantum effects into account (G₂), they become mathematically possible; in astrophysical observations (G₃), they remain undetected. Conclusion: wormholes remain hypothetical objects without experimental