Dr Clare Burrage reaches beyond the stars to understand more about dark matter and dark energy.Our planet is just a tiny speck in the enormous vastness that is the universe. Within that huge universe, there is plenty that we still don’t understand – and that’s what Dr Clare Burrage, of Britain’s University of Nottingham, finds most exciting.
Her lecture at the Hong Kong Science Museum, part of Science Alive 2016, attempted to explain the inexplicable, and focused on what we know – and what we don’t – about two of the biggest mysteries in the universe: dark matter and dark energy.
The stuff we know about the universe – all the stars and planets and other observable things – make up only about five per cent of everything that’s out there. The vast majority of the rest of the universe is dark energy, which makes up about 68 per cent, and dark matter, which accounts for about 27 per cent.
So how do we know all this dark stuff is there if we can’t even observe it? We know because we can observe things happening in the universe that can’t be explained with our current understanding of physics. That tells us there must be some other factors at play.
Burrage explains that dark matter and dark energy have a big part to play in the expansion of the universe. Dark energy is what causes the expansion, and dark matter is the stuff that is getting pushed out. But we still don’t know much about either one.
“So for dark matter, there is kind of a best guess,” Burrage says, “which is that there’s a new type of particle.” She says that the discovery of a new particle with different properties could help explain some of the other mysteries in physics.
“People will tell you that with the discovery of the Higgs Boson particle our knowledge of physics is complete, and we now know everything,” she says. “But that’s not true. There are still puzzles that we don’t understand.”
But new information and advancements happen every day in the field of theoretical physics and cosmology. “By far and away the most exciting thing happened a month ago which was when they discovered gravitational waves for the first time,” Burrage says.
Until the discovery of these waves, the only way scientists could gather information about objects far away in space was from light. Now, Burrage explains, we have two ways of gathering information, which opens up exciting new avenues for research and understanding.
“It’s really equivalent to the first time somebody looked through a telescope. Suddenly there was so much more you could see in the sky and so much more you could learn. This is sort of like our new telescope: gravitational waves coming from distant objects,” she says.
“They’ve only published one observation and it’s already changed what we understand about what our universe is made of. So it’s going to be just absolutely revolutionary.”
And scientists need all the new information they can get to tackle the mystery of dark energy.
“For dark energy, we don’t even really have a best guess at the moment,” Burrage admits. “We genuinely don’t have a theory, even a theory, that explains what we see.”
But that in itself is part of the fun. “It’s either quite worrying or quite exciting, depending on how you look at it,” she says. “It’s hard to predict which developments are going to lead to something more. It’s only by pushing the boundaries that you’re going to get advances in technology.”