Nasa astronaut Scott Kelly takes his first space walk just hours before setting a new US flight record. Kelly will break the American record for NASA’s longest single space trip that has stood at 215 days — more than seven months — since 2007. Kelly has been living on the International Space Station (ISS) since March this year. He’ll remain there until March 2016 Continue reading...

Although its sudden discovery has spooked scientists, astronomers confirm that the 1,300ft-wide space rock will remain further away than the moonA Halloween asteroid is due to scream past the Earth on the last day of the month, missing the planet by just 300,000 miles – frighteningly close by astronomical standards.But scientists say there is no need to be scared, even on Halloween. The space rock, travelling at around 22 miles per second, will remain further away than the moon. Continue reading...

Readers answer other readers’ questions on subjects ranging from trivial flights of fancy to profound scientific conceptsWe see a small part of the electromagnetic spectrum as colours. Do the parts we can’t see have colour? If not, why not? If they do, can they be described in a way we can comprehend?David Taylor, Spancil Hill, County Clare, Ireland Continue reading...

Famed for its chocolate, Mars wants to reduce the number of food safety scares through the creation of its Global Food Safety CenterListeria, E coli, adulterants and fungal toxins are all too common in food supplies around the world, sickening and even killing untold numbers of people every year.

Campaign group Science is Vital rallied passionate, good-natured support for UK science at their ‘Science: As Vital As Ever’ event in Conway Hall on Monday 26th October. With the Comprehensive Spending Review in November threatening further cuts to the UK research budget, scientists and supporters of science came together to argue the case for the social, cultural and economic value of science. And to plead with George Osborne not to let the UK research base endure another five years of decline. The event drew a capacity crowd and heard speeches from many of the country’s most prominent advocates for science. Scientist and photographer Robert Dickinson captured some of the highlights. The campaign continues online. Continue reading...

Rocked by the news that processed meat could be terribly bad for you? Well, chimney sweeping, salted fish and fracking also appear on the list compiled by the International Agency for Research on CancerAfter Monday’s bombshell news from the World Health Organisation that bacon, ham and sausages are carcinogenic, you can be forgiven for wondering just what exactly is safe for you to come into contact with – let alone eat.Handily, the International Agency for Research on Cancer – a body that collects and publishes cancer figures worldwide – has a list of the 116 substances and activities (for some of them are more verb than noun) that are now considered to cause cancer. Continue reading...

Consensus builds among scientists though review of evidence also finds there is not enough data on whether pesticide causes population declineThere is a strong scientific consensus that bees are exposed to neonicotinoid pesticides in fields and suffer harm from the doses received, according to a new analysis of the all the scientific evidence to date.

Imlygic, which bursts melanoma cells open and triggers immune response, can shrink localised tumours but is not proven to extend life, says FDAThe US Food and Drug Administration has approved a first-of-a-kind drug that uses the herpes virus to infiltrate deadly skin cancer tumours, reducing their size in some cases.Related: The Guardian view on meat and cancer: a little of what you fancy will do you no harm | Editorial Continue reading...

Nasa probe will fly within 30 miles of the moon’s south pole, sampling water vapour in a bid to learn more about vast frozen underground oceansThe Cassini spacecraft is in for an icy shower as it passes within 30 miles (50km) of one of Saturn’s many moons on Wednesday.Jets of of water vapour and frozen particles erupting from the south pole of the moon, Enceladus, are expected to provide the best sampling yet of its underground ocean. Continue reading...

I share some of Patrick Barkham’s views about the annual moving of clocks, forward and back (Notebook, 27 October), but he is wrong to suggest that there is anything irrational in the asymmetry of the times when the clocks are moved. The Earth moves round the sun in an ellipse, rather than a circle, thus the times between the two equinoxes, spring to autumn and autumn to spring, are not equal. The tilt of the Earth’s axis to the plane of the orbit introduces a further asymmetry. For most of the first half of the year, the sun time is behind our clock time and ahead for the second half. We do not, of course, have to do anything with the clock. We could just decide to move the nation’s timetable to an hour earlier in summer and move it back in the autumn. An alternative would be to start the day at 8am instead of 9am, which would have the effect of BST all the year round.

Scientists Sriram Subramanian and Asier Marzo explain how new sonic tractor beam technology lifts and spins objects in the air using only the forces produced by a field of ultrasonic waves. The technology allows for what the scientists call “containerless transportation”, which could find uses in applications where material is dangerous to handle, or at risk of being contaminated by people or machinery, in particular medicine Continue reading...

Scientists in Spain demonstrate new technology that uses a field of ultrasonic waves to grab tiny objects and move them around. The technology works by using an array of flat speakers to produce acoustic holograms. Just as visual holograms are produced in 3D from interfering light waves, so acoustic holograms are made by interfering sound wavesRead the force awakens: tractor beam becomes a reality

Scientists hope to start trials in dementia patients after rat study suggests drug reduces brain inflammation and encourages neuron growthAn inexpensive drug used to prevent asthma attacks in children and adults may help to rejuvenate ageing brains, according to a study in rats.Researchers found that a six week course of the drug, montelukast, improved memory and learning in older rodents, with their performance in cognitive tests nearly matching that of much younger animals.

Our new study proves the harm to child health, so cutting public consumption makes political senseIn October 2013, the Mexican Congress did the unthinkable. They passed a peso-per-litre tax on sugared beverages, as well as a similar tax on junk food. This, in a country where some counties still don’t have potable water and where the poverty rate is 52%. Last week, the Mexican Congress did something even more unthinkable. They gutted their tax, cutting it by half. This, despite soda tax revenues that topped $19bn a year, and despite a diabetes prevalence rate of 12% compared with the US rate of 9.3%.The tax caused sugary drink consumption in Mexico to drop 6%. The Instituto Nacional de Salud Publica (the public health officials) called this a success; Hacienda (the treasury department) called it a failure. Why did they gut the tax when it provided revenue to a cash-strapped exchequer? Continue reading...

Having only one child is something many people frown upon, but the reasons for this are unscientific and unfounded.Maybe it’s my age. Maybe it’s not feeling up to incubating another human. Maybe it’s my unshakeable dislike of Dustbuster-shaped family cars, or the thought of having worse than a one-to-one ratio of parents to children at any given time. Whatever my reasons, I’ve experienced surprising resistance since I started admitting we might be stopping at just the one. “Wait till you hit 40 and panic!” and “But she’ll be so lonely!” or “Oh, hooray! You’re pregnant again, right? Oh my god, sorry, it’s just your billowy top.”Here I thought I’d be freed of childbearing harassment once I’d had a child. (Incidentally there’s a good post about nosing in on women’s fertility status that recently went viral). When people used to ask if I was “trying for a baby” I’d go Full Snark and say things like “Nope, we’re trying for a panda. It’ll be tough, genetically – but the world needs more.” Being confronted about having an “only” has rendered me more tongue-tied. It can feel like no-man’s land: you’re an ousted traitor of the No Kids Club, but if you didn’t know better, you could be made to feel like you’re not a real parent unless you double down.

With caesareans, fingers being amputated and jaws being reset, these gruesome yet exquisite drawings of the living – and the dead – hark back to a time when the cutting edge of medicine was, frankly, terrifying Continue reading...

Tsar Alexander III’s remains to be used to help identify the last two children of Tsar Nicholas II, murdered in 1918Russian investigators say they plan to exhume the remains of Tsar Alexander III, father of murdered Tsar Nicholas II, in the latest twist to authenticate the remains of the slain royal family.Related: Ex-tsar Nicholas II executed: from the archive, 22 July 1918 Continue reading...

World Health Organisation finds processed meats such as sausages and ham carry an increased risk of bowel cancer, and red meat ‘probably’ does tooAustralians do not need to stop eating red meat but should limit their intake, say experts responding to international research showing it can increase the risks for certain types of cancer.Related: Barnaby Joyce plays down research linking processed meats to cancer Continue reading...

One in 20 use amphetamine for same purpose, survey reveals, with many feeling pressured to achieve a certain body imageMore than 30% of gym-goers in the UK use some form of drug or dietary supplement to lose weight, a study has found, amid fears body image anxiety fuels a rise in the use of performance and image-enhancing drugs.More than 5% of people who regularly attend gyms have gone further by using the illegal stimulant amphetamine for this purpose, according to researchers from the University of Hertfordshire, who have presented their preliminary findings to MPs. Continue reading...

US archeologists found the wooden coffin of the unknown soldier on the Peloponnese peninsula, with jewellery, a bronze sword and ivory combs insideUS archaeologists in Greece have uncovered the skeleton of an ancient warrior that has lain undisturbed for more than 3,500 years along with a huge hoard of treasure, according to the Greek culture ministry.The treasure is “the most important to have been discovered in 65 years” in continental Greece, the ministry said. Continue reading...

The World Health Organisation (WHO) says that eating processed meat can lead to bowel cancer in humans, and red meat is a likely cause of the disease. The report was released on Monday and was carried out by WHO’s International Agency for Research on Cancer (IARC). Dr Kurt Straif, head of the IARC monographs programme, says that the risk of developing colorectal cancer increases with the amount of processed meat consumed Continue reading...

Will we all be eating brains by sunset, or will the virus die out of its own accord? Here’s the solution to today’s puzzle about the zombie virusEarlier today I set you a Halloween puzzle with the following set-up:An infected zombie has a 1/3 chance of passing the infection to a single human, a 1/3 chance of passing the infection to two humans, and a 1/3 chance of passing the infection to no one. No one in the UK is infected by the zombie virus until a single zombie arrives. Continue reading...

Did Alex Bellos’s Halloween problem scare the living daylights out of you, or did you slay the beast? What are the chances that the UK’s zombie outbreak will infect two people or less? What are the chances it will it just die? On average, how many humans will each zombie infect? And what is really spooky about the answers? Continue reading...

The young artist’s new work at New York’s Whitney tries to make viewers feel as though they’re floating in the heavens – with help from Aretha FranklinFrom space, the Earth appears to plunge into night every 45 minutes. Floating over the dark planet on a moonless night in a sky blacker than you thought possible, all the Earth might look like to you, says Nasa astronaut David Wolf, “is the absence of stars … You can reach into a shadow so black that your arm can appear to disappear.”Wolf went for a walk over the world from the Mir Space Station in the late 1990s and saw the Earth seemingly vanish. His recollection so moved New York-based artist Rachel Rose when she heard it on NPR that she went to considerable lengths to track him down for a personal retelling. “I sent handwritten letters, emails and cold-called any source I could find linked to him on the internet. I tried everything for around three or four months. I didn’t think I would be able to get to him,” she says. Continue reading...

Oil heartlands of Abu Dhabi, Dubai, Doha and Iran’s coast will experience higher temperatures and humidity than ever before on Earth if the world fails to cut carbon emissionsThe Gulf in the Middle East, the heartland of the global oil industry, will suffer heatwaves beyond the limit of human survival if climate change is unchecked, according to a new scientific study.The extreme heatwaves will affect Abu Dhabi, Dubai, Doha and coastal cities in Iran as well as posing a deadly threat to millions of Hajj pilgrims in Saudi Arabia, when the religious festival falls in the summer. The study shows the extreme heatwaves, more intense than anything ever experienced on Earth, would kick in after 2070 and that the hottest days of today would by then be a near-daily occurrence. Continue reading...

The following Q&A was produced by the World Health Organisation’s International Agency for Research on CancerQ. What is processed meat?A. Meat is described as processed when it has been transformed through salting, curing, fermentation, smoking or other processes to enhance its flavour or improve preservation. Most processed meats contain pork or beef, but they may also contain other red meats, poultry, offal and meat by-products such as blood. Continue reading...

UN health body says bacon, sausages and ham among most carcinogenic substances along with cigarettes, alcohol, asbestos and arsenicBacon, ham and sausages rank alongside cigarettes as a major cause of cancer, the World Health Organisation has said, placing cured and processed meats in the same category as asbestos, alcohol, arsenic and tobacco.The report from the WHO’s International Agency for Research on Cancer said there was enough evidence to rank processed meats as group 1 carcinogens because of a causal link with bowel cancer.

From Uber to Airbnb, ratings rule our world, but the system is far from perfectUber drivers are motivated to offer a better customer experience by being rated by every passenger at the end of each journey. Likewise, their passengers are incentivised to behave politely because their drivers rate them in turn. A recent version of the Uber app even allows passengers to see those ratings. And although anyone – driver or passenger – can have a bad day, it is valuable to see a person’s average rating, namely to describe, with a simple and standardised measure, how good a passenger or driver he or she is. It sums up how people behaved in the past, and predicts how they are likely to behave in the future.But perhaps the most attractive element of this system is that it puts pressure on people to gain and maintain a desirable reputation, something they may not feel compelled to do otherwise. I go to great lengths to maintain my almost perfect 4.9 Uber rating, but I don’t really care what regular taxi drivers think of me – a feeling that appears to be mutual. Continue reading...

As economy and population expand, government looks for new ways to keep homes comfortable and stop crops being ruined before they get to marketNarendra Sharma dreads the summer. Temperatures climb above 40C even before the sun has hit the pitted, potholed surface of the streets through which he pushes his vegetable barrow day after day. Even when dusk falls there is little respite.“It’s tough, even if you are used to it. And the worst of all is that I lose money,” he said. Continue reading...

It is an integral part of modern life, but now the US is waking up to the environmental cost of such massive energy consumptionIt was a sun-drenched afternoon, with another autumnal heatwave cooking the concrete of Los Angeles, but Joanne Pilecki hugged her green fleece close as she stepped into a cinema foyer.

Dr Richard Leakey on paleoanthropology, what still surprises him about hominids and the the technology that could revolutionise the study of our ancestryDr Richard Leakey has been immersed in paleoanthropology for over 50 years. From 1968 to 1999 he built up Kenya's National Museums, and led an international research effort studying human evolution within the Turkana Basin in northern Kenya.Speaking to the Guardian's Rowan Slaney, he tells us what continues to surprise him about hominids and explains the technology that could revolutionise the study of our ancestry. In turn we asked: how certain can we be that humans originated in East Africa? Continue reading...

This year’s seasonal flu is the zombie virus. But how far across the population will it spread?Greetings, guzzlers.As it’s Halloween this week... Continue reading...

This week’s Halloween brain-eater, sorry, brainteaser, was devised by an expert in the spread of diseases such as Ebola. The world is overrun with zombies, and the first has just arrived in the UK. Will the zombie outbreak die out, or are we all in mortal peril? Can you solve it? Continue reading...

Scientists have long looked for physical markers of our inner lives. Now it turns out that the length of your fingers reveals much about you. Take this test to find outDid you know you can measure your personality with a ruler? First, measure the length of your index finger from crease to tip. Then do the same for your ring finger. Divide the first number by the second to calculate your 2:4 digit ratio. For example, my index finger is 7.8cm and my ring finger is 8.2cm, so my ratio is 7.8÷8.2=0.95, which is precisely the average for a man. For a woman it’s 0.97. Continue reading...

Spending more time ‘forest bathing’ can have a positive effect on depression. Rob Penn on what we owe treesIn autumn our woodlands are at their most enchanting. The sunlight angles gently in to create a changing mosaic of gold and brown; leaves twist and stall as they fall to the floor; branches chatter in the strengthening winds. It is the time of year when trees seem keenest to communicate with us, and when our bond with them is most vital.The polymath American biologist EO Wilson first propounded his theory of biophilia – that we have a deep affiliation with other forms of life, like trees, which is instinctive and rooted in our biology – in the mid-80s. Around the same time, Professor Roger S Ulrich completed one of the first and best-known studies in the interdisciplinary field now known as environmental psychology. Ulrich’s conclusion – that patients recovering from surgery in rooms with a window facing natural surroundings took less medicine for pain relief than patients with a window facing a brick wall – was groundbreaking. Continue reading...

Disney’s robotic healthcare assistant may become a reality, thanks to advances in inflatable technologyFor those who thought inflatable technology began and ended with air beds and water wings, think again. The latest trends suggest that inflatables will soon be taking on important roles in hospitals and farms – as a part of robotics.The vast majority of robots in the world reside in factories – they are solid mechanical machines with arms that can grip, hold objects, and carry out tasks such as assembling, painting, or welding. Their ability to be accurate, reliable and to work 24/7 has long made them attractive to manufacturers and they are now catching the eye of hospital managers who are under increasing pressure to provide services but lack the funds to pay the staff to do them. Robotic surgical systems have been in use for more than a decade, providing help and increased accuracy for some operations, but they are niche. Arguably a much bigger impact can be made by using robots to help with more mundane but far more numerous tasks, such as lifting patients on to beds and helping them to the bathroom. Continue reading...

The palaeontologist whose team found Homo naledi has been criticised for rushing his findings and making basic errorsIt remains one of the most dramatic human fossil finds of recent years. In 2013, in a tiny, cramped chamber in the Rising Star cave near Johannesburg, researchers led by palaeontologist Lee Berger uncovered several thousand bones of ancient humans. The team now concludes that these are the remains of a previously unknown species, Homo naledi.The news, announced last month, made headlines around the world. However, the discovery has since become mired in controversy. Some scientists claim the bones belong to an already known species of human, Homo erectus. Others have criticised Berger for claiming that the remains come from a deliberate burial, while several have complained that he has not been able to date his finds. Continue reading...

Across the world, tech companies are engineering a future of robot helpers and smart healthcare for the elderly. But this new vision of the welfare state lacks one crucial element: dignitySingapore’s old people have never had it so good: now, there’s a robot to help them keep fit and healthy. RoboCoach, their new best friend, offers both encouragement and exercise tips. Its message is unambiguous: get your exercise routines wrong – skipping them no longer seems optional – and you put extra strain on the country’s overstretched public finances.As Singapore’s minister for communication and information put it, RoboCoach “is able to ensure that old people perform the exercise routines correctly so as to get maximum benefit from their workouts”. Free advice to Singaporean authorities: why not couple RoboCoach 2.0 with a fancy wristband like Pavlok, sending an electric shock every time its users slack off and deviate from established objectives? Continue reading...