How white holes are made

1 Collapse of the core

When a gigantic star – with a typical mass much more than 20 times the mass of the Sun – dies, sometimes a black hole is formed. When we refer to a star dying it means that it no longer has any nuclear fuel to burn, and this means that gravity is able to override the outward force. The core has no choice but to collapse in on itself, and the catastrophic

explosion of a supernova results.

2 A cosmic plughole

Shrinking smaller and smaller, the core continues to pale in significance compared to its former stellar glory, collapsing further into an even smaller size. However, while it has shrunk to a speck, all of its mass is concentrated in a very small area. This is known as a singularity, which might be small, but is so very heavy that it has the ability to

bend space-time.

3 The makings of a doughnut

A star’s core can still be found to be spinning

when it decides to collapse. Crumbling to the minuscule, yet hefty singularity, it begins to rotate faster and faster and spins so fast that what’s left of the star’s material spreads out and is moulded into a doughnut shape. Space-time is no longer focused on a single point; it’s now finding itself being wrapped

around this space ring, creating a tunnel.

4 Punching through space-time

The tunnel punches its way through the fabric of space-time and, almost in an unusual state of reversal, may even emerge backwards in time and into the past. This tunnel, which can feasibly work its way into another parallel universe, is called an Einstein-Rosen bridge – or more simply put, a wormhole. Any matter grabbed by the black hole is

passed through this tunnel.

5 Meet the white hole

If you were to travel through a wormhole, you would reach its far side: the white hole. Matter pulled in by the black hole will emerge from the singularity found at the white hole’s centre and be released back into space. Just as nothing can escape a black hole, it’s not possible to

enter a white hole.