Nuclear fission involves splitting atomic nuclei, and is the process used in nuclear power stations. Fusion, as its name suggests, involves fusing nuclei and is the power source of the stars. While both fission and fusion release energy, the process and amount is very different. Fission exploits the instability of nuclei of heavy elements like …
Most species of aquatic snail have a comb-like gill. The oldest groups have two gills but the majority have lost one, to make room inside their spiral shell. As snails moved to the land, they swapped gills for a primitive lung, called the pallial cavity. Some snail groups moved back to freshwater and a few …
The same bacteria that is used to ripen many cheeses, including Munster, Limburger and Port-du-Salut, also lives on our skin and eats dead skin cells. It’s called Brevibacterium; as it digests it gives off S-methyl thioesters, which smell cheesy. Another skin-munching bacterium is Staphylococcus epidermidis, which produces the cheesy, vinegary-smelling isovaleric acid. The final ingredient …
The best supercomputers fill rooms, cost millions, and are thousands of times faster than your computer at home. They are usually used for complex scientific problems involving lots of maths. They are used to predict the weather, model brains, or help predict the result of a nuclear explosion, for example. Some are used to test …
EXHAUSTION – Let’s say you dig a 1×1 m hole, which gives you enough room to wield a shovel. For each metre that you dig down, you have to remove a cubic metre of earth, weighing 1.6 tonnes. Even if you have some kind of bucket elevator so that you don’t need to lift the …
If People Dug Down At 1m/s, What Would Kill Them? Read More »
A recent theory holds that humour evolved because it encourages us to perform the arduous task of fact-checking our assumptions about other people’s intentions and perspectives. By this account, mirth is the reward we get when we debunk one of our presumptions and see things suddenly in a new light -jokes are ‘super-normal stimuli’ that …
Wolves bury food that they can’t eat immediately. This keeps it safe from scavengers like crows and the cold ground helps to preserve it. Birds don’t have a good sense of smell so they find it harder to locate these buried caches than wolves do. Dogs retain this behaviour and will bury toys or bones …
Thermal energy – the physicist’s term for heat – comes in various forms, including infrared radiation, which is part of the electromagnetic spectrum, like visible light. As such, this form of heat can be blocked by objects, creating a shadow. But the other forms of heat can still get to us via, for example, the …
Approximately 2 to 5 per cent of the population suffers from recurring nightmares, and often the reason is that they have survived some kind of life-threatening situation, such as a car accident or a violent attack. Indeed, one study estimated that between 50 to 70 per cent of patients with post-traumatic stress disorder (PTSD) experience …
The extinct bird Argentavis magnificens weighed about as much as an adult human and it had a wingspan of 7m – four times the average human arm span. This bird had lots of other adaptations to allow it to fly though, including the muscles to support these wings and flap them. Hang gliders, which allow …
Drones are radio-controlled flying gadgets with several propellers that may be used for filming, racing, and in the future perhaps even widespread delivery of parcels. Military drones resemble small aircraft with no pilots. Some can take off, fly and land by themselves. They can perform surveillance over enemy territory or even deploy missiles to attack …
The viruses that cause ordinary colds are all quite species-specific. Dogs can’t catch human colds (or vice versa), but they do have their own version, called canine infectious tracheobronchitis or kennel cough. The influenza virus is much more adaptable though. Bird, pig, horse, dog and human flu have all been shown to jump the species …
Planes are designed to cope with extremes of temperature, allowing them to take off from searingly hot desert runways before cruising in the bitter -55°C cold of the stratosphere just minutes later. Yet even the most sophisticated aircraft can be put at risk by freezing conditions. When ice builds up along the leading edges of …
Credit is usually given to the Scottish-born scientist and engineer Alexander Graham Bell, who was granted a US patent for what he called an ‘acoustic telegraph’ in 1875. His claim comes complete with the famous story of Bell using his invention to call his colleague in the next room with the words: “Mr Watson, come …
No Wi-Fi network is completely safe if you have the wrong settings on your phone or computer. When you browse http pages, you are transmitting and receiving unencrypted text; this makes it easy to intercept, making your passwords vulnerable. Only https pages are secure. If you have Sharing enabled on your computer, it is possible …