How It Works
No. 153Welcome to How It Works, the magazine that explains everything you never knew you wanted to know about the world we live in. Loaded with fully illustrated guides and expert knowledge, and with sections dedicated to science, technology, transportation, space, history and the environment, no subject is too big or small for How It Works to explain.
nesta edição
science of sore heads
Dear How It Works, I have headaches a lot of the time, and I was wondering what causes them. I know it can be a lack of sleep, or stress, but I was wondering what the scientific explanation was. What does being stressed do to the brain to make it hurt, and what is the pain? Nestor Thank you for your question, Nestor. Headaches can be a horrible experience, and have a variety of causes. Most of the time, what feels like pain in the brain isn’t caused by the brain at all. There are many nerves in the muscles and blood vessels in your head, neck and face that relay pain. Stress, enlarged blood vessels and muscle tension can all be responsible for bringing on these headaches. As these nerves start to…
football facts
Hi HIW, I have been watching the Euros recently. I think lots of people enjoy the simplicity of the sport, but has the game changed much since it was invented? Rory O’Gorman Football was invented over 100 years ago, and the sport is constantly adapting its rules. When the game began, rules were less official, so they could vary based on location. Many games allowed players to carry the ball in their hands, which goes against the fundamental rules of today. It was also common for players to kick others during an attack on the goal. In 1863, the first official rules were made and written down. During games at this time, there was no crossbar on goals – this meant goals were accepted at any height. A referee makes key decisions during the game.…
brain gym
Spot the difference See if you can find all six changes between the images below Sudoku Complete the grid so that each row, column and 3x3 box contains the numbers 1 to 9 EASY DIFFICULT Wordsearch FIND THE FOLLOWING WORDS… FACILITY MEDAL ATHLETE DOWNING CRAB AQUIFER ENERGY DIESEL ROCK BRAIN OVEN SEAT What is it? Hint: These usually form as a result of an overproduction of melanin… A Check your answers Find the solutions to last issue’s puzzle pages SPOT THE DIFFERENCE QUICKFIRE QUESTIONS Q1 122 years, 164 days Q2 All of the above Q3 Oort Cloud Q4 Copper blood Q5 Red devil deer Q6 1939 WHAT IS IT? …CORN FLAKES…
what makes high-gi foods more quickly digested and absorbed?
A food’s glycemic index (GI) rates how fast it raises glucose levels in your blood. Many things affect this. Sometimes food breaks down into small particles that are easier to absorb. If food contains glucose as an ingredient, that easily gets into blood. But food often contains starch instead, which is a long, chain-shaped molecule. The links in that chain can be sugars like glucose. These chains break down in different parts of our guts, releasing glucose more slowly. Foods also contain fibre, containing complex chains made of sugars like glucose that break down even more slowly in our guts. DID YOU KNOW? Avocados are extremely calorific, but are very good for you…
do ‘immortal’ jellyfish really live forever?
It’s technically possible for these animals to live forever, but only in perfect lab conditions. Once the jellyfish has sustained an injury or can’t find enough food to survive, it shrinks back down to its juvenile form. It reabsorbs its tentacles and sinks to the seafloor as a polyp. It begins maturing and eventually becomes an adult again. This process is called transdifferentiation, and it’s extremely rare. If there were no predators in the ocean the immortal jellyfish would really live up to its name, but jellyfish of all growth stages are eaten by fish, turtles and sea slugs. The adults only have a weak sting, and the polyps are defenceless blobs ready for the taking. DID YOU KNOW? Immortal jellyfish can grow a new body every month…
can batteries discharge themselves over time without being put in a device?
Yes, it’s called self-discharge. Lithium-ion batteries lose about two per cent of their charge per month if left charged. This is because batteries are electrochemical, rather than purely electronic devices. That’s reflected in their names. In lithium-ion batteries, ions of the element lithium move between electrodes, releasing electrical energy as they do so. They do this quickly on demand when we use our gadgets. But it can also happen when the battery is left alone.…
