Has science found its first white hole?
The universe is littered with the weird and wonderful and GRB 060614 could turn out to be one of the weirdest and most wonderful of them all.
GRB 060614, which we’ll call Ralph to smooth things along, was a gamma-ray burst with some very puzzling properties detected by Nasa’s Swift satellite on June 14, 2006.
Gamma-ray bursts are the most powerful explosions in the universe. They usually come in two flavours: long bursts, which are normally caused by the sudden release of energy that occurs when a collapsing star forms a black hole in a massive supernova event, and short bursts, which occur when two neutron stars – the superdense remains of dead stars – collide.
[Image above: GRB 060614 is a strange gamma-ray burst detected by Nasa’s Swift satellite on June 14, 2006. It originated in a galaxy 1.6billion light years away and didn’t fit in with any of the existing models for gamma-ray burst creation.
Since its detection, more than a dozen telescopes – including Hubble – have studied the peculiar burst. Is it evidence for the existence of a black hole’s mirror image: a white hole?]
Ralph’s gamma ray burst lasted 102 seconds, which put it firmly in the long burst camp. But there was a problem: no supernovae had been recorded anywhere in Ralph’s vicinity. At the time, its discoverers were baffled, and exclaimed: ‘This is brand new territory, we have no theories to guide us.’
Now, five years later, a theory has emerged: it could be a white hole.
A white hole is a theoretical beastie that exists as a set of equations that were a by-product of Einstein’s theory of relativity. It is basically a black hole in reverse. If a black hole is an object from which nothing can escape, then a white hole is an object into which nothing can enter – it can only radiate energy and matter.
[Graphic: How white holes (might) be formed – click to bend spacetime and magnify]
It is relativity that makes white holes super-weird. A black hole represents a pinch in the fabric of the universe (spacetime) where everything is dragged into a single infinitely small point known as a singularity.
Relativity suggests the universe shouldn’t be allowed to get all pointy like this but should always continue in an infinite curve. The solution to this was to suggest that instead of terminating spacetime at a point, a black hole creates a funnel, or worm hole, which feeds out into a white hole in the universe’s past (don’t forget, spacetime is an amalgam of space and time, so if you can bend space, then you can also bend time).
Whether Ralph proves to be the first observed white hole remains to be seen. Many physicists would argue strongly it will not but, until then, it’sexciting to believe that it might be.
The kitchen sink analogy
If all this talk of spacetime distortions, singularities and wormholes is just too much, you can compare black holes and white holes with two slightly less bizarre events that happen in your kitchen sink every day.
Think of your plug hole as being the singularity at the centre of a black hole.
As the plug hole draws water into it, the water accelerates and spirals just like matter being drawn into a black hole. Just like a black hole, nothing can leave the plug hole while water is flowing into it.
You can simulate a white hole simply by turning on your kitchen tap.
When tap water flows into the sink, it hits the surface and spreads out in a circular pattern.
As long as the water is flowing from the tap, nothing in the sink can pass the edge of the ring of water – just as nothing can pass the edge of the stream of matter flowing from a white hole.