Wormholes are general relativistic short-cuts through space-time, currently unobserved, but made famous (or infamous) by Star Trek, Stargate and Sliders, and little understood. Originally described by Einstein and others – famously the Einstein-Rosen bridge mentioned briefly in SF ever since – but shown to be dynamically unstable to any infalling light or mass. That is until Carl Sagan challenged his friend Kip Thorne to come up with someway of making wormholes stable. Ever since that famous thought-experiment wormholes have been described and designed in a multitude of physics papers – but do they exist?
Nikolai Kardashev and Igor Novikov are instantly recognisable names to space-nerds like myself – inventor of the Kardashev scale of civilisations, and master of black holes respectively. Just recently they’ve collaborated on a paper… Astrophysics of Wormholes …which describes what wormholes, in varying states of traversibility, might look like. And infact they’d look a lot like the Active Galactic Nucleii of many, many galaxies.
Another team of researchers have also suggested a different way to find wormholes – inside Black Holes. A Black Hole is usually described as “sucking in everything” like some sort of irresistable force, but in actual Black Hole physics the picture is more complicated. From a distance a bare Black Hole is just a mass with gravity like any other – but invisible (and thus a candidate for dark matter) -, but within a few radii of the Black Hole (its radii not yours) the situation gets dramatic. Small Black Holes have immense tidal forces and will shred anything into atoms. Within 3 radii and the Black Hole does strange things to space-time – if it’s rotating then space-time gets dragged with it, creating an ergosphere. Nothing can resist turning with the Black Hole within the ergosphere, but dumping mass into it might give you enough energy to escape back out. A similar process allows Hawking Radiation to escape and whittle away the mass of a Black Hole over immense aeons of aeons of time.
But within the Event Horizon there’s no escape, not even for light. Space & time trade places and all motion is towards the Singularity, where the mass of the original object that formed the Black Hole has been crushed to oblivion leaving a distortion in space-time. A rotating Black Hole has a Singularity shaped like a ring – and if you can pass through the ring you’ve passed through a wormhole. One that’s normally inaccessible. However according to recent computations of the effects of an electromagnetic excitation of the Black Hole, found here… Electromagnetic Excitation of Rotating Black Holes and Relativistic Jets …the Event Horizon can be opened up and the wormhole revealed. Perhaps if the wormhole goes somewhere this might actually be useful.
And that’s the puzzle. Relativity gives no clear indication of where wormholes end. They might link to other places (and times) in our Universe or in other Universes. When the worm-ways of the Universe are finally explored there will be a whole new breed of adventurers required to travel to their far-ends, risking being lost in a wholly other Universe and time. After hardy explorers have mapped the wormhole network of the Universe what will happen then?
According to Ray Kurzweil they’ll be the communications web of the The Intelligent Universe, our ultimate descendent, the Universe-filling HyperComputer, which will include us within its matrix. His is a grand cosmic vision in which the super-exponential growth in computation will drive us to turn the Universe into Mind-full Computronium and live in a virtual world that caters to our whims. If we aren’t already there…