Life is full of clever questions that need smart answers. Our science writer, Linda Pretorius, tries to answer a few.

Near-death experiences

Has science crossed the (flat)line? So to speak, yes. Neuroscientists found that brain activity in rats briefly surged 30 seconds after their hearts stopped beating. The same pattern was seen whether death was due to a heart attack or suffocation.

But perhaps it was just a glitch? It’s unlikely. The EEG patterns showed highly synchronised neural activity, similar to that of an awake, active brain.

What could have caused the heightened activity? It’s not quite sure, but the researchers believe that reduced oxygen and glucose supply to the brain spurred high-level neural processing.

So near-death experiences are real? It could well be for some people. And the well-organised brain activity patterns seen in the current study seem to offer some scientific explanation for the ‘realer than real’ perceptions about 20% of heart attack survivors reported in previous research.

How birds got their wings

You mean they didn’t always have wings? Nope. Birds originated from small, meat-eating dinosaurs that walked on their hind legs about 150 million years ago.

So, what gave them their wings? Well, it wasn’t Red Bull... Palaeontologists recently discovered that a dramatic lengthening of forelimbs and a shortening of the hind limbs helped to, uhm, uplift this group of dinosaurs.

How so? Longer forelimbs resulted in a limb shape that could support a lift force in air, while shorter, more compact hind limbs likely helped to reduce drag during flight. Together, these changes made for efficient flight.

And the advantages of spreading their wings? The changes in limb size likely allowed these bird ancestors not only to get up and away easily but also to perch lightly on tree branches. So, these early birds may well have been able to snatch the worms from another group of flying reptiles dominating the skies at the time.

The stuff of life

So has the mystery of the origin of life on Earth been solved? Well, at least one more piece of the puzzle fell in place. Scientists recently found that icy comets crashing into Earth may have blasted life into the planet.

So, life on Earth came from outer space? The ingredients for life, yes. Comets typically consist of an icy mix of water, carbon dioxide, ammonia and methanol. Experiments showed that when such a mix was shock compressed, several different amino acids, which are the building blocks of proteins, formed. This suggests that comets brought the ingredients for life, while the impact with early Earth provided the necessary energy to make it happen.

Does this mean there could be life elsewhere too? It certainly ups the odds. In fact, one of Saturn’s moons also consists of frozen water and organic molecules. A high-speed comet crash could well provide enough energy to let complex organic molecules such as amino acids form.

Article first appeared in TechSmart 121, available online here.