Remember: a bad memory is actually good for you

Remember: a bad memory is actually good for you

It’s not uncommon to hear people wishing that they had a better memory. “If only I weren’t so forgetful”, they complain. “If only I could reliably remember my computer password, and that my neighbour’s name is Sarah, not Sandra.” If this sounds familiar then I know how you feel. As a psychologist who studies the science of remembering, it’s especially embarrassing to me that my memory is frequently dreadful. When asked whether I had a good weekend, I often struggle to immediately recollect enough details to provide an answer.

The five greatest balls of fire over Earth

The five greatest balls of fire over Earth

We live on a moving target in a cosmic firing range. Each day, the Earth is bombarded by about a hundred tonnes of space debris. It may sound alarming, but this is really nothing to worry about. Most of the objects that fall towards our planet are pretty small – typically about the size of a grain of sand or even smaller – and burn up in the upper atmosphere tens of kilometres above the ground.

What is time – and why does it move forward?

Imagine time running backwards. People would grow younger instead of older and, after a long life of gradual rejuvenation – unlearning everything they know – they would end as a twinkle in their parents' eyes. That’s time as represented in a novel by science fiction writer Philip K Dick but, surprisingly, time’s direction is also an issue that cosmologists are grappling with.

What would happen if Earth fell into a black hole?

What would happen if Earth fell into a black hole?

Black holes have long been a source of much excitement and intrigue. And interest regarding black holes will surely grow now that gravitational waves have been discovered. Many of the questions I am asked regard how “true” science fiction concerning black holes might be, and whether worm holes, such as those featured in Stargate, are real or not. Invariably though, the one item that is almost assured to come up are the largely gruesome ways in which black holes might theoretically affect human beings and the Earth itself.

Health Check: what happens to your body when you’re dehydrated?

Health Check: what happens to your body when you’re dehydrated?

Water is essential for human life. It accounts for for 50-70% of our body weight and is crucial for most bodily functions. Any deficit in normal body water – through dehydration, sickness, exercise or heat stress – can make us feel rotten. First we feel thirsty and fatigued, and may develop a mild headache. This eventually gives way to grumpiness, and mental and physical decline.

Did the Vikings use crystal ‘sunstones’ to discover America?

Did the Vikings use crystal ‘sunstones’ to discover America?

Ancient records tell us that the intrepid Viking seafarers who discovered Iceland, Greenland and eventually North America navigated using landmarks, birds and whales, and little else. There’s little doubt that Viking sailors would also have used the positions of stars at night and the sun during the daytime, and archaeologists have discovered what appears to be a kind of Viking navigational sundial. But without magnetic compasses, like all ancient sailors they would have struggled to find their way once the clouds came over.