Lie detectors don’t work. Body language is unreliable. But there are ways to tell if someone is lying. You just have to listen carefully to what they’re saying

Psychopathy isn’t rare, just widely misunderstood and overlooked – even by those who have it

Psychologists want us to carve out more alone time, to give our brains a chance to relax and recharge

Move aside, Ludwig

Most of the Universe seems to be missing – or at least, we don’t know what 95 per cent of it is. And at this point, my biggest question is, does it matter? Most of the missing stuff (68 per cent) is something called 'dark energy'. It was 'discovered’ in 1998 when astronomers observed that distant supernovae (exploding stars) were dimmer than expected. We knew the Universe was expanding, and so the supernovae should become fainter over time, but we thought that expansion was slowing down. After all, the Universe is full of matter and that matter produces gravity, which should be pulling everything together. Instead, it seemed the expansion was accelerating. So, the physics world decided on a new kind of universal constant, dark energy. It’s a similar story for dark matter (the other 27 per cent). It was something used to fix the difference between what our model was predicting and what we were seeing in the Universe. The trouble is, we’re still nowhere near understanding exactly what either of them are. So, back to my question. Does it matter? Well, we also don’t really know what gravity is, fundamentally, but we know a lot about how it behaves. And that’s the important part – we can model what it does extremely well. This lets us probe planets, stars and phenomena light-years away from us and so it seems to matter less, even as the mystery boils on. But if you would really like to know what’s going on, one set of cosmologists has a wild new theory to help us understand what dark energy could be. Find out what that theory is, in this issue.

Wondering whether a colleague secretly dislikes you? Psychologists explain five signs to look out for

Two neutron stars collided and produced a record-breaking X-ray flash

Stop it before it takes over

Whether it's bums and tums or your arms and hips, flab can gather in all sorts of places. Here’s what controls body fat distribution