Science fiction films like Arrival (pictured) portray how humans might try to communicate with alien lifeforms. But is it even possible, or wise? Photo / Supplied
Science fiction films like Arrival (pictured) portray how humans might try to communicate with alien lifeforms. But is it even possible, or wise? Photo / Supplied
From Close Encounters of the Third Kind to Arrival, Hollywood has long been fascinated with the idea of communicating with space aliens.
But is it even possible? Or wise?
In recent years, a fierce debate has erupted over proposals to beam messages toward distant solar systems.
Until now, the search for extraterrestrial intelligence - or SETI - has largely been limited to listening for radio signals from other galaxies.
Having failed to detect a single peep, some scientists want to turn the tables and begin broadcasting missives from Earth into deep space.
As physicist Stephen Hawking warned in 2010, "If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans."
But, in a new discussion paper, scientists say it's unlikely alien life forms could see or hear the way humans do.
Even on our own planet, eyesight varies widely.
Bats perceive the world via radar, Indian pythons see in infrared and honeybees navigate by detecting polarised light.
In 1977, Nasa's Voyager rocketed into space carrying recordings of animal noises, poetry readings and a library of music, from classical to Chuck Berry.
The mission prompted Saturday Night Live to joke that aliens had intercepted the craft and transmitted a four-word reply to Earth: "Send more Chuck Berry".
In truth, Voyager's audio cargo would undoubtedly mystify any interplanetary astronauts who stumbled upon it, said the University of California's Professor Don Hoffman.
"We can't even understand the language of dolphins despite decades of effort."
The chance of aliens deciphering our words are similarly remote: "About zero," he put it.
How we breathe affects our emotional judgment
The rhythm of breathing creates electrical activity in the human brain that enhances emotional judgments and memory recall. Photo / 123RF
The rhythm of breathing creates electrical activity in the human brain that enhances emotional judgments and memory recall.
That's according to scientists at Northwestern University in the US, whose world-first findings also show these effects on behaviour depend critically on whether you inhale or exhale and whether you breathe through the nose or mouth.
In their study, individuals were able to identify a fearful face more quickly if they encountered the face when breathing in compared to breathing out.
Individuals also were more likely to remember an object if they encountered it on the inhaled breath than the exhaled one.
The effect disappeared if breathing was through the mouth.
"One of the major findings in this study is that there is a dramatic difference in brain activity in the amygdala and hippocampus during inhalation compared with exhalation," explained Assistant Professor Christina Zelano, the new paper's lead author.
"When you breathe in, we discovered you are stimulating neurons in the olfactory cortex, amygdala and hippocampus, all across the limbic system."
The Earth's "technosphere" - the sum of all of the infrastructure and technology humans have created - now weighs 30 trillion tonnes, scientists say. Photo / 123RF
Scientists have made the first estimate of the sheer size of the physical structure of the planet's technosphere - suggesting that its mass approximates to an enormous 30 trillion tonnes.
The technosphere is comprised of all of the structures that humans have constructed to keep them alive on the planet - from houses, factories and farms to computer systems, smartphones and CDs, to the waste in landfills and spoil heaps.
A new study led by geologists at the University of Leicester in the UK suggests the bulk of the planet's technosphere is staggering in scale, with some 30 trillion tonnes representing a mass of more than 50kg for every square metre of Earth's surface.
Study author Professors Jan Zalasiewicz described the technosphere as "all of the structures that humans have constructed to keep them alive, in very large numbers now, on the planet: houses, factories, farms, mines, roads, airports and shipping ports, computer systems, together with its discarded waste".
"Humans and human organisations form part of it, too - although we are not always as much in control as we think we are, as the technosphere is a system, with its own dynamics and energy flows - and humans have to help keep it going to survive."
The bug you'd never, ever want to meet
Scientists have found a bacterium in an underground cave that demonstrated resistance to most antibiotics used today, including so-called "drugs of last resort". Photo (stock image) / 123RF
US researchers have just discovered in a cave in New Mexico what would be a microbiologist's worst nightmare.
The scientists found one bacterium called Paenibacillus 300 metres underground that demonstrated resistance to most antibiotics used today, including so-called "drugs of last resort" such as daptomycin.
These micro-organisms had been isolated from the outside world for more than four million years within the cave.
The results showed the bacterium was resistant to 18 different antibiotics and used identical methods of defence as similar species found in soils.
This suggested that the evolutionary pressure to conserve these resistance genes has existed for millions of years - not just since antibiotics were first used to treat disease.
Among the different ways that the bacteria could be resistant to antibiotics, the scientists identified five novel pathways that were of potential clinical concern.
Finding these new pathways was particularly valuable, as it gave researchers time to develop new drugs to combat this type of resistance, potentially decades before it would become a problem for doctors and their patients.
