For as long as we have tried to figure out the nature of reality, we have grappled with the concept of empty space. Around 400 BC, when the ancient Greek philosopher Democritus conceived of small, indivisible bodies called atoms, he supposed there must also exist a void surrounding them: a featureless, unchanging vacuum in which they moved.
Today, the void remains a potent idea for understanding the universe, but we have come to realise that it is anything but featureless. More than a century ago, Albert Einstein’s theory of gravity revealed that space-time is stretched and warped by the matter it contains. Later, quantum theory introduced the idea of virtual particles, which momentarily appear and disappear in a vacuum, making pure nothingness seem like an intangible, bubbling soup.
This alone would surely have shocked Democritus, but I believe we should go further still. I have spent four decades trying to find a way to combine Einstein’s theory of gravity and quantum mechanics. This long journey has led me to a startling conclusion: there is another rich structure hidden within the void, which can be traced to ethereal entities called virtual black holes.
The influence of these stretches across the entire cosmos, linking space-time in subtle ways that ultimately cause Einstein’s theory to fail – forming a bridge between the smallest scale of the quantum realm and the cosmic one of gravity. Enticingly, I have now begun to grasp how this hidden property of space-time may be the source of dark energy, the mysterious force that is tearing…
