relativity. It would include quantum mechanics and it would include information.

Hawking’s rather simple equation brought us a step closer to understanding the relationship between quantum physics and black holes.

When an object crosses over the edge of a black hole, its event horizon, the object

enters basically a realm of empty space and darkness and it continues to be dragged towards

the center of the black hole toward what we call the singularity where it gets crushed

out of existence. Every object, in some sense, contains information because it contains a

very specific arrangement of particles. So where is the information that describes the

arrangement of those particles? Where does it go?

Hawking’s description of this process was that the energy remains but the information disappears. For many years - for decades - people

wondered, ‘Is Hawking right?’ Is the information obliterated - it disappears from the universe

- or is it still there, and perhaps can in some way retrieved? The destruction of information

was counter-intuitive and it didn’t match the rest of things we knew. In all parts of

physics we had a situation where information doesn’t get destroyed. So it was a bit puzzling.

This debate furiously went back and forth up through the 80s and into the 90s, when

people finally began to articulate this new principle, this holographic principle. And

what it said is that all the things that were falling inside a black hole were somehow captured

in a preserved image at the horizon itself. So if the information is not lost on the surface,

it is not lost inside because they are equivalent. All of the information about those objects

- what they were like in their three-dimensional existence - was preserved or encoded on the

surface of the black hole. And that’s a little bit like a hologram. Well that suggests

that maybe that idea may apply more broadly to the universe as a whole. Maybe the three-dimensional

objects - us, everything in the world around us - maybe all of the information in these

objects is carried, is smeared around a distant two-dimensional surface that surrounds us.

And we’re just, in some sense, a holographic projection of that distant data.

The holographic principle tells us something quite astonishing. It says that our ideas of volume, the real

world in a sense, might be a kind of illusion.