Snworld

Could direct air capture prevent climate change ? direct air capture (dAC) is an appealing way to tackle climate change: just pass ambient air over chemicals that absorb the Co2 driving global warming, and then use or store the Co2. dAC differs from the better-known carbon capture and storage (CCs) in that it can be done anywhere, not just at big sources of Co2 such as power stations. it’s more effective than natural Co2 ‘scrubbing’ using trees and plants, and can be performed where the Co2 is most easily stored or re-used. unlike CCs at power stations, dAC must be effective at removing the far more dilute Co2 in ambient air. this demands special equipment and chemicals, plus renewable energy sources producing zero Co2. that has led to grave doubts about the economic viability of dAC. For now, it remains an intriguing but impractical remedy for global warming. 

How do we know when something is wet?  our skin contains lots of nerve endings that respond to different stimuli. there are receptors for touch, vibration, heat, cold and pain – but not for wetness. water is such a ubiquitous component of all living cells that it would be difficult for a nerve cell to avoid firing constantly in response to its own composition. instead, wetness seems to be a property that our nervous system learns to recognise, based on a mixture of cold, pressure and texture. A 2014 study at Loughborough university found that hairy skin is more sensitive to wetness than smooth skin, which may be because hairy skin has more temperature sensitive nerve endings. when you are born, you don’t feel wet or dry, you just feel cold or warm. over time we learn that the feeling of cold cloth sticking to our skin means that we’ve sat on a wet park bench.

Why do different countries use different mains voltages? the biggest disparity is between the usA on 110V and most of the rest of the world on 230V. America’s lower voltage goes all the way back to thomas edison, who introduced direct current (dC) mains electricity at 110V. edison’s rival nikola tesla showed that long power lines transmitted alternating current (AC) more efficiently than dC. His AC approach won out, but he stuck with edison’s 110V. But by the time electrification spread to europe early in the 20th Century, lamps had filaments that could give out more light and handle greater power loads. so the Berliner elektrizitätswerke company in Germany established 230V as the standard. 

Why do snakes have slits for pupils? Vertical pupils are an adaptation for ambush hunting. A 2010 study at sydney university found that of 127 Australian snake species, the ones that ambushed their prey by night had vertical pupils, while those that actively chased down prey in the day had round pupils. the constriction of round pupils helps distant prey stay in focus, but it also lets in less light. Vertical pupils improve vision across a wider range of light levels, and enable the animal to detect horizontal movement more effectively. it’s also possible that vertical pupils are more camouflaged, since they break up the round outline of the eye

Farmers under pressure to reduce chemical pesticides can take heart from the news that the US Department of Agriculture is about to start trialling a device that can kill insects with a laser. Developed by Seattle company Intellectual Ventures Lab (IVL), the ‘Photonic Fence’ isn’t really a fence at all, but a small box containing lasers, cameras and an AI computer system. The cameras scan the air around the device for 100 metres, and the AI system measures the shape, speed, acceleration and wingbeat frequency of any bugs detected, to establish which are potentially harmful. Any insects identified as a threat can be zapped by the lasers, with a ‘kill rate’ of up to 20 insects per second. By deploying several such devices, farmers could effectively create a virtual fence around their crops that kills harmful pests but leaves bees and other beneficial or harmless insects unharmed. As well as protecting crops, it’s hoped the Photonic Fence could also prove useful in the fight agai...

The relationship between trees and air pollution is a complicated one. Particulate matter suspended in polluted air tends to settle onto leaves, and certain gases including nitrous dioxide (NO2) are absorbed by leaves’ stomata, filtering the air and reducing pollution levels slightly. But trees and other vegetation also restrict airflow in their immediate vicinity, preventing pollution from being diluted by currents of cleaner air. In particular, tall trees with thick canopies planted alongside busy roads can act like a roof, trapping pockets of polluted air at ground level. To reliably improve air quality, city planners need to give careful consideration to how trees are placed.

Mercury levels in the oceans have tripled since the Industrial Revolution, thanks to mining and the burning of fossil fuels. All sea creatures absorb some of this heavy metal directly, and, once it’s in the body, there’s no way of getting rid of it. The amount of mercury in fish varies between species. Long-lived predators like tuna and swordfish tend to contain the most, because they also absorb mercury from their prey and they’ve had a long time to accumulate it. The lowest levels are found in short-lived species lower down the food chain, such as oysters and shrimp.

Humans need to sweat to survive in warm conditions, and that’s only possible if the combination of temperature and humidity – known as the wet-bulb temperature – stays below around 35°C. According to a 2012 study by scientists at MIT, this limit could be reached globally if our planet warms by around 12°C. Fortunately, few scientists think global warming will do this in the foreseeable future.

Even after passing through water treatment plants, small quantities of chemical compounds from cleaning products can find their way into rivers, ponds and lakes and have adverse effects on aquatic life. Phosphates in laundry and dishwasher detergent have a fertilising effect, triggering the widespread growth of algae that saps away the water’s oxygen, reducing biodiversity. By reducing water tension, surfactants allow other pollutants in water bodies to be absorbed more easily by plants and animals. Many other compounds can be toxic to wildlife, or affect growth and reproduction, for instance by mimicking the effects of hormones in mammals and fish

Since the Martian atmosphere is about 100 times less dense than Earth’s, the ‘lift’ a frisbee experiences would also be about 100 times less. But the gravitational force on Mars is about a third of that on Earth, so a frisbee on Mars would act as if it is about 33 times heavier (100/3). Since the lift depends on the size of the frisbee, the angle of attack and the velocity it is thrown (as well as the air density), it would still be possible to make a frisbee glide, but it would require much more effort on the part of the thrower.

Beer typically has around 40 calories per 100ml (one pint = 568ml). To get your daily 2,000 calories just from beer, you’d need to drink 11 pints every day, which is hardly healthy. But the alcohol is the least of your problems. Beer, even real ale or Guinness, contains no fat, almost no protein and – crucially – no vitamin C. Without any source of vitamin C, you’ll experience symptoms of scurvy in two or three months and be dead in six.

Antarctic icefish have colourless blood with no red blood cells and no haemoglobin, the oxygen-carrying pigment. This probably comes down to a genetic mutation, and means their blood carries 90 per cent less oxygen than red blood. They survive partly because frigid Antarctic waters are oxygen-rich. Icefish also have enormous hearts that pump huge volumes of blood around their bodies, making sure they get enough oxygen. Antifreeze in their blood stops them from freezing (the salty Southern Ocean gets down to -2°C) but, as they are so well-adapted to the cold, their future in a warming world remains uncertain. 

TEN BIGGEST BANGS ON EARTH Seattle Kingdome demolition  When: 26 March 2000 Holding up to 66,000 sports fans in its 19.821 million m3 capacity, this stadium became the largest building to be demolished by explosives when it was destroyed in 2000. Chicxulub Impact When: 65 million years ago The chicxulub crater in mexico, a staggering 180km wide, was created when a 10km-wide meteorite crashed into earth. the impact is believed to have been a major contributing factor in the extinction of the dinosaurs. Heligoland explosion When: 18 April 1947 The royal navy tried – and failed – to blow up a whole north sea island and the huge German naval base it carried by detonating around 4,000 tonnes of explosives, one of the world’s biggestever single detonations. Despite that, the island remained intact. Mt Toba When: 75,000 years ago When the supervolcano mt toba erupted, it launched at least 2,800km3 of magma and ash into the atmosphere, causing a six-year volcanic win...

TEN MOST EXPENSIVE EXPERIMENTS 01 $150 Billion International Space Station (£92 billion) Weighing nearly 420 tonnes and floating 370km above the earth, the iss has been continuously occupied by astronauts from various countries since the first crew docked on 2 november 2000. 02 $20.6 Billion International Thermonuclear experimental reactor (£12.3 billion) In 2010 construction began in france on what will become the world’s largest tokamak fusion device – a magnetically confined core in which fuel will be heated to temperatures greater than 150,000,000°c. 03 $8 Billion   James Webb Space Telescope (£4.9 billion) Scheduled to launch in 2018, this telescope – a nasa project with input from the european and canadian space Agencies – will investigate how galaxies form by peering out to the farthest reaches of space. 04 $6.65 Billion  International linear collider (£4.1 billion) A planned particle accelerator even bigger than the large Hadron collide...

TEN GAME-HANGING FOSSIL FINDS Marine fossils Discovered: 6th century Bc Where: Greece lived: various periods the Greek philosopher Xenophanes reasoned that the fossils of marine creatures found on land were evidence of sea covering the earth in previous eras. Mosasaurus Discovered: 1764 Where: maastricht, netherlands lived: cretaceous (around 70–65 million years ago) this aquatic reptile was the first to be identified as an extinct species, by Georges cuvier, and the first genus of such an animal to be named, in 1822 by William conybeare. Megalosaurus Discovered: 1676 Where: oxfordshire lived: Jurassic (201–145 million years ago) A fossilised femur from this carnivore (left) was discovered in 1676, but it was nearly 150 years later that William Buckland and colleagues named the ‘huge lizard’ – and recognised it as the first-known dinosaur. Iguanodon Discovered: c1821 Where: sussex lived: early cretaceous (around 125 million years ago) one of three genera inc...

Ten countries most affected by climate change 01 Honduras Climate Risk Index: 10.17 Droughts and floods hit food production. 02 Myanmar Climate Risk Index: 11.83 Warmer temperatures have led to huge increases in the spread of water-borne diseases. 03 Haiti Climate Risk Index: 16.83 the number and power of hurricanes have increased significantly in recent years. 04 Nicaragua Climate Risk Index: 17.17 two category-five storms in the past 15 years claimed thousands of lives. 05 Bangladesh Climate Risk Index: 19.67 frequent flooding of the Ganges delta wipes out crops, destroys homes and spreads diseases. 06 Vietnam Climate Risk Index: 24.00 increases in flash floods, landslides and other natural disasters causing many deaths. 07 Philippines Climate Risk Index: 31.17 increasingly frequent, intense natural disasters, especially floods,are claiming thousands of lives. 08 Dominican Republic Climate Risk Index: 31.33 flooding and erosion are bot...

TEN MOST DENSELY POPULATED COUNTRIES 01 Monaco  Area: 2.02km2  Population: 36,136  density: 18,068 people/km2 02 Singapore Area: 716km2 Population: 5,399,200 Density: 7,669 people/km2 03 Vatican city Area: 0.44km2 Population: 800 Density: 1,818 people/km2 04 bahrain Area: 757km2 Population: 1,234,571 Density: 1,631 people/km2 05 Malta Area: 315km2 Population: 4,16,055 Density: 1,321 people/km2 06 Maldives Area: 298km2 Population: 3,17,280 density: 1,065 people/km2 07 Bangladesh Area: 1,47,570km2 Population: 1,52,518,015 density: 1,034 people/km2 08 palestine Area: 6,020km2 Population: 4,420,549 density: 734 people/km2 09 taiwan Area: 36,191km2 Population: 23,361,147 density: 645 people/km2 10 barbados Area: 430km2 Population: 2,74,200 Density: 638 people/km2

TEN HIGHEST CAPITAL CITIES 01 La Paz Bolivia 3,640m Sitting in a bowl with mountains on all sides, the Bolivian capital is located in the valleys of the Andes. With a population of 877,363, the city’s more affluent citizens tend to reside in its lower-lying neighbourhoods, while poorer residents make their homes at higher altitudes within the capital. 02 Quito Ecuador 2,850m 03 Thimphu Bhutan 2,648m 04 Bogotá Colombia 2,625m 05 Addis Ababa Ethiopia 2,355m 06 Asmara Eitrea 2,325m 07 Sana’a Yemen 2,250m 08 Mexico City Mexico 2,240m 09 Nairobi Kenya 1,795m 10 Kabul Afghanistan 1,790m

THE TEN SMALLEST COUNTRIES (BY AREA) 01 Vatican city 0.4 square km 02 Monaco 1.9 square km 03 nauru 21 square km 04 tuvalu 26 square km 05 San Marino 61.2 square km 06 liechtenstein 160 square km 07 Marshall Islands 181 square km 08 Saint Kitts and nevis 269 square km 09 Maldives 298 square km 10 Malta 316 square km

TEN CITIES LEFT ABANDONED Pripyat Where: Ukraine Abandoned: 1986 Following the Chernobyl nuclear disaster, the entire population of around 50,000 residents were evacuated – never to return. Oradour-sur-Glane Where: France Abandoned: 1944 A German Panzer division destroyed this town, killing 642 inhabitants. Varosha Where: Cyprus Abandoned: 1974 this holiday playground of the rich was abandoned after the invasion by turkey. Kolmanskop Where: Namibia Abandoned: 1954 this mining town was abandoned when its diamond yield declined. Kayaköy Where: Turkey Abandoned: 1923 the non-muslim inhabitants of this town were forced to relocate after the Greco-turkish War. Salton riviera Where: California Abandoned: 1970s local fish population died out; so did local tourism. Humberstone Where: Chile abandoned: 1961 Abandoned after the saltpeter-mining industry declined. now a unesco World Heritage site. Craco Where: Italy Abandoned: 1963 the instability o...