Science

Science highlights: A virtual universe and the vampire apocalypse

Sarah Wild

The world of science is filled with interesting, quirky and downright strange discoveries. Science editor Sarah Wild chooses some of this week's best.

Illustris can recreate 13-billion years of cosmic evolution in a cube of 350-million light years. (Graphics: John McCann, M&G)

More bang for the universe’s buck
There was a spark that created our universe. All the matter that we can see – as well as the more than 90% that we can’t – exploded out of a single point. We don’t know why, but scientists are now closer to figuring out what happened in the milliseconds and billions of years afterwards.

Astronomers from the MIT/Harvard-Smithsonian Centre for Astrophysics have created a complete computer simulation of what happened: from that spark until now.

“Until now, no single simulation was able to reproduce the universe on both large and small scales simultaneously,” said lead author Mark Vogelsberger from the centre.

Enter Illustris: a virtual simulation that can recreate 13-billion years of cosmic evolution in a cube of 350-million light years. “Previous attempts to simulate the universe were hampered by a lack of computing power and the complexities of the underlying physics,” the centre said.

The simulation models for both normal matter – the stuff we can see – and dark matter, the other more than 90% of our universe that we can’t see, using 12-billion 3D pixels. It took 8 000 CPUs running in parallel three months to complete. If you’d done this at home on your computer, it would have taken about 2 000 years.

“Illustris is like a time machine. We can go forwards and backwards in time. We can pause the simulation and zoom into a single galaxy or galaxy cluster to see what’s really going on,” said co-author Shy Genel from the Centre for Astrophysics. And now, sitting in front of your computer, you can watch the universe unfold on illustris-project.org.


Vegazzle your table 

In the past, your parents lectured you on eating your vegetables, and there was always that suspicion that your portion was larger than theirs.

But now science is joining in the dinner-table conversation. Researchers have reviewed 20 studies published over the past 19 years to determine the links between strokes and eating fruit and vegetables. “The combined studies involved 760?629 men and women who had 16?981 strokes,” according to the American Heart Association.

The research, by Chinese scientists, was published in the association’s rapid access journal report.

It reported that stroke risk decreased by 32% with every 200g of fruit consumed each day and by 11% with every 200g of vegetables eaten daily. “Improving diet and lifestyle is critical for heart and stroke risk reduction in the general population,” said Dr Yan Qu, the study’s senior author, director of the intensive care unit at Qingdao Municipal Hospital and professor at the medical college of Qingdao University in China.

“In particular, a diet rich in fruit and vegetables is highly recommended because it meets micronutrient and macronutrient and fibre requirements without adding substantially to overall energy requirements.”

Sad to say, the older you get the more it would appear that your mom was right all along.


The vampire apocalypse starts here 

The Greek historian Herodotus wrote about a fountain of youth in the 5th century BCE, a spring whose waters would restore youth to the drinker.

It would appear that scientists in the 21st century have identified another source of youth, albeit more macabre: the blood of children.

In the prestigious journal Nature Medicine, the University of California San Francisco’s Saul Villeda and colleagues write: “Exposure of an aged animal to young blood can counteract and reverse pre-existing effects of brain ageing at the molecular, structural, functional and cognitive level.”

By injecting aged mice with the blood of young mice, the researchers found that the old mice had improved mental acuity and memory, and that it reversed many of the side effects of ageing in the brain. Globally there are millions of people suffering from age-related brain diseases, including Alzheimer’s, and this number is set to increase as improvements in medicine enable people to live longer.

Billions of dollars are being spent to discover ways to reverse the ageing process.

But is the blood of children possibly too high a price?


Road worrier: Mind the bump 

There is a great deal of medical advice telling pregnant women what they should and shouldn’t do. Some of them seem obvious – don’t smoke, don’t take recreational drugs, avoid eating predator fish because they contain traces of mercury, do moderate exercise and eat healthy foods. Research out of Canada has added another cautionary measure: be careful of driving.

According to a study, which included more than half a million women, pregnant women in their second trimester or later were 42% more likely to be involved in a serious traffic accident.

“Pregnant women often worry about air flights, scuba diving, hot baths and other topics in maternal health, yet individuals may overlook traffic accidents despite their greater health risks,” says Dr Donald Redelmeier, lead author and a physician at the department of medicine, University of Toronto.

He cautioned that even minor accidents could have an impact on maternal and baby health.

“Almost all traffic accidents could be prevented by a small change in driver behaviour. The absolute risks among pregnant women, however, are still lower than among men of this age.”


Swimsuits jump the shark 

It’s the kind of thing Franz Kafka would have written about if he’d lived near the ocean: turning humans into sharks. Sharks have an average cruise speed of about 8km/h, whereas a human’s is about 2km/h.

Most of a shark’s speed is owed to its aerodynamic shape, but for years scientists have suspected that its skin plays a role.

To the observer it looks sleek and silky – and if you’re in the water with the shark, you don’t notice it at all – but in reality it is rough and sandpapery. It is covered with sharp, V-shaped scales, called denticles, which reduce the drag of the water on the shark’s body.

Scientists from Harvard University have now created shark skin using 3D printers and found that it increases its speed by more than 6%.

They are talking about creating swimming suits made of fake shark skin, but acknowledge that the manufacturing challenges are daunting. And it probably wouldn’t help you outswim a shark anyway.


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