NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team
Almost all of our universe is missing – or at least, we’ve never seen it directly. Will we ever know what’s out there? That’s the question that ²¹²Ô»åÌý will be asking at .
All the stuff we can see, from stars and planets to galaxies and supernovae, makes up a paltry 5 per cent of the contents of the universe. The majority of the rest consists of dark energy, a mysterious force that is pulling the cosmos apart. But 27 per cent of the universe is dark matter – an invisible counterpart to ordinary matter that adds bulk to galaxies.
When it comes to pinning down dark matter, for decades the most common candidates have been WIMPs, weakly-interacting massive particles too heavy for us to make using particle colliders such as CERN. But a landmark experiment earlier this year suggested that the answer might instead lie in much lighter particles that possess a tiny electric charge.
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Meanwhile others have suggested that dark matter is merely a fudge invented to account for an incomplete understanding of the workings of gravity, and doesn’t really exist.
The fate of the universe
The situation is even more confused for dark energy, which accounts for 68 per cent of the universe. Since the first evidence for its existence turned up in 1998, physicists have assumed it pervades the cosmos with a constant density. But new results suggest that idea could be about to be overturned, and a dark energy that varies in density may be on the horizon – a discovery with deep implications for how long our universe is likely to last.
Come to Â鶹´«Ã½ Live in London on 20 September to hear Heymans, an astrophysicist at the University of Edinburgh, explain why she thinks that a true understanding of the dark universe will require entirely new physics.
On 22 September, Ghag, an astrophysicist at University College London, will describe how the hunt for dark matter is heating up, and how we may soon even be able to produce it ourselves.
Â鶹´«Ã½ Live is our award-winning festival of ideas and discoveries. The four-day event will feature more than 120 speakers giving thought-provoking talks on everything from to the .
