World's Most Advanced Computers Unravel the Universe's Most Primitive Processes (Op-Ed)

The visualiztion, Magnetic Fields in Core-Collapse Supernovae depicts the magnetic field inside the shock surface of a supernova, and was created using the GenASIS code on the Oak Ridge Leadership Computing Facilitypetascale computer, Jaguar, work that continues on Titan. Credit: Eirik Endeve, Christian Cardall, Reuben Budiardja, Anthony Mezzacappa, Dave Pugmire.

Gregory Scott Jones, a writer who covers supercomputing. He contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

There is an idea, popular in New Age circles, that humans represent the universe's primary self-awareness.

In other words, our consciousness is actually the Cosmos realizing it exists; is mankind the only creature to ever look up at the sky and know the vast distances to the stars, or the fact that we are physically the product of their demise? This is, I imagine, the sort of thing Carl Sagan had in mind when he said "humans are the stuff of the cosmos examining itself." Far out for sure.

But this self-awareness, if it's indeed real, presents many questions. Big ones. And we're getting answers thanks to those primitively simulated brains we call computers. Big ones. The Universe, it seems, has begun to write its autobiography.

The irony is hard to ignore. The idea that some of the most advanced machines in the modern world will piece together the most basic processes in all of time is rapidly becoming a reality.

Today's supercomputers are necessary for solving an entire range of complex scientific challenges, from the complexities of climate change to the properties of new materials to the ideal aerodynamics of vehicle design. But few problems require such massive computing power as do those born in the heavens.

Unfortunately, recreating the Big Bang and watching the universe unfold in a laboratory is out of the question for obvious reasons. But with empirical data from satellites, probes and seriously powerful telescopes, and the simulation potential of computers pushing 30 petaflops — or 30 thousand trillion (quadrillion) calculations per second — scientists are getting a much clearer picture of how this whole universe thing unraveled, and how we came to be.

Observation reveals what was created in the early moments of the universe: The cosmic microwave background, or CMB, represents the dawn of time just after (well, about 378,000 years after) the Big Bang. Its current geography is the result of roughly 14 billion years of formation, plenty of time for researchers to play with piecing the puzzle together.

But we're getting there, one step at a time. For example, thanks to decades of observation and extremely sophisticated applications running across many thousands of processors, a team of researchers led by Salman Habib is using Argonne National Laboratory's Mira and Oak Ridge National Laboratory's Titan supercomputers to see how tiny variations in the Big Bang can grow to form enormous clumps that now host stars and galaxies.

The simulations take place across billions of light years of space in thousands of time steps with the potential to squash or validate theories and confirm or disprove much of what we thought we knew about how the universe behaves, including the elusive "dark energy," the reigning champion in our quest to explain how the universe expands, and why the expansion rate is currently accelerating.

Supercomputers are necessary for such complex simulations, principal investigator Salman Habib has said, due to their sheer speed, massive amounts of memory and their communication-oriented architectures. Habib's application achieved a sustained performance in excess of ten petaflops, completely out of reach just years ago, allowing the team to witness the evolution of the universe from the largest scales down to those characteristic of galaxies.

"In a way supercomputers compress the enormous reaches of space and time that are characteristic of the cosmos, and allow us to interact with them on the — by comparison — incredibly short scales of human perception," said Habib.

If the Universe is self-aware, simulating its creation is akin to forcing it to watch embarrassing home movies of its childhood.

But what about us? After all, if we are in fact the latest and greatest universal incarnation, where is our birth story? Consider core-collapse supernovas (CCSNs), or stars greater than eight times the size of our sun, but no greater than around 40 times.

These massive elemental factories self-implode, a violent act that leaves in its place all the elements up to iron, i.e., all of the necessary ingredients for life. When Crosby, Stills, and Nash sang "we are stardust, we are golden, we are billion-year-old carbon," they had CCSNs in mind, whether they knew it or not.

Researchers can now simulate in three dimensions many of the implosions that created us, a feat impossible just a couple of years ago. We now know that neutrinos play a significant, if not the dominant, role in these massive elemental creation events, as a team of researchers using the Titan supercomputer located at Oak Ridge National Laboratory is achieving neutrino-driven explosions across a range of stellar masses in two dimensions, giving credibility to their model.

The same team used Jaguar, Titan's predecessor, to explain how a neutron star could become the more rapidly rotating pulsar, a problem featured on the cover of the June 1, 2012, issue of Science, which explored the top unsolved problems in astrophysics. Known as the standing accretion shock instability, or SASI, researchers now have a relevant description of how a rotating neutron star picks up steam, work that was recently validated by observation in the February 20, 2014, issue of Nature.

Forget about home movies. This is the universe staring at its reflection in the mirror.

These monumental developments are occurring across a wide range of astrophysics and cosmology, from black hole accretion to the formation of individual planets and stars, fields with concepts so vast that it is difficult, if not impossible, to imagine a computer powerful enough to ever resolve them completely. Nevertheless, the potential for the world's latest and greatest calculators to solve the biggest questions, both metaphorically and literally, is potentially limitless, as are the questions. The universe is, after all, a very old and very large place.

Our best estimate of the structure of the universe as we know it, the standard model, accounts for roughly 5 percent of its total mass; the rest we embarrassingly refer to as "dark matter." We can't see it, can't feel it, can only infer it. The resolution and definition of dark matter and "dark energy" would be among the most significant scientific achievements of all time, and simulations on the world's most powerful computers will doubtless play a large role.

But problems of this magnitude will no doubt require technologies more powerful than today's leading systems. Luckily for us, the next era is unfolding before our very eyes. The world's fastest computers may soon approach the exascale, capable of crunching quintillions of calculations per second, or nearly an entire order of magnitude faster than current systems. And once again the most advanced machines on the planet will be called upon to answer the most fundamental questions: Who are we? And where do we come from?

Our earliest history is intimately connected with our near future. The universe must think it's pretty smart.

The views expressed are those of the author and do not necessarily reflect the views of the publisher. This article was originally published on Live Science.

Ancient Earth hammered by double space impact

We've all seen the films where an asteroid hurtles towards our planet, threatening civilisation.

What's less well known is that menacing space rocks sometimes come in twos.

Researchers have outlined some of the best evidence yet for a double space impact, where an asteroid and its moon apparently struck Earth in tandem.

Using tiny, plankton-like fossils, they established that neighbouring craters in Sweden are the same age - 458 million years old.

Details of the work were presented at the 45th Lunar and Planetary Science Conference in The Woodlands, Texas, and the findings are to be published in the Meteoritics and Planetary Science journal.

However, other scientists cautioned that seemingly contemporary craters could have landed weeks, months or even years apart.

A handful of possible double impacts (or doublets) are already known on Earth, but Dr Jens Ormo says there are disputes over the precision of dates assigned to these craters.

"Double impact craters must be of the same age, otherwise they could just be two craters right next to each other," the researcher from the Centre for Astrobiology in Madrid, Spain, told BBC News.

Dr Ormo and his colleagues studied two craters called Lockne and Malingen, which lie about 16km apart in northern Sweden. Measuring about 7.5km wide, Lockne is the bigger of the two structures; Malingen, which lies to the south-west, is about 10 times smaller.

Binary asteroids are thought to form when a so-called "rubble pile" asteroid begins to spin so fast under the influence of sunlight that loose rock is thrown out from the object's equator to form a small moon.

Telescope observations suggest that about 15% of near-Earth asteroids are binaries, but the percentage of impact craters on Earth is likely to be smaller.

Only a fraction of the binaries that strike the Earth will have the necessary separation between the asteroid and its moon to produce separate craters (those that are very close together will carve out overlapping structures).

Calculations suggest around 3% of impact craters on Earth should be doublets - a figure that agrees with the number of candidates already identified by researchers.

The unusual geological characteristics of both Lockne and Malingen have been recognised since the first half of the 20th Century. But it took until the mid-1990s for Lockne to be formalised as a terrestrial impact crater.

In the last few years, Dr Ormo has drilled about 145m down into the Malingen structure, through the sediment that fills it, down to crushed rocks known as breccias and deeper, reaching the intact basement rock.

Lab analysis of the breccias revealed the presence of shocked quartz, a form of the quartz mineral that is created under intense pressures and is associated with asteroid strikes.

This area was covered by a shallow sea at the time of the Lockne impact, so marine sediments would have begun to fill in any impact craters immediately after they were created.

One-two punch

Dr Ormo's team set out to date the Malingen structure using tiny fossilised sea creatures called chitinozoans, which are found in sedimentary rocks at the site.

Their method, known as biostratigraphy, allows geologists to assign relative ages to rocks based on the types of fossil creatures found within them.

The results revealed the Malingen structure to be the same age as Lockne - about 458 million years old. This seems to confirm that the area was rocked by a double asteroid strike during the Ordovician Period.

Dr Gareth Collins, who studies impact cratering at Imperial College London, and was not involved with the research, told BBC News: "Short of witnessing the impacts, it is impossible to prove that two closely separated craters were formed simultaneously.

"But the evidence in this case is very compelling. Their proximity in space and consistent age estimates makes a binary-impact cause likely."

Simulations suggest the asteroid that created Lockne was some 600m in diameter, while the one that carved out Malingen was about 250m. These measurements are somewhat larger than might be suggested by their craters because of the mechanics of impacts into marine environments.

Dr Ormo added that Malingen and Lockne were just the right distance apart to have been created by a binary. As mentioned, if two space rocks are too close, their craters will overlap. But to qualify as a doublet, the craters can't be too far apart, because they will exceed the maximum distance at which an asteroid and its moon can stay bound by gravitational forces.

"The Lockne impactor was big enough to generate what's known as an atmospheric blow-out, where you blow away the atmosphere above the impact site," said Dr Ormo.

This can cause material from the asteroid strike to spread around the globe, as happened during the huge Chicxulub impact thought to have killed off the dinosaurs 66 million years ago.

The Ordovician event wasn't powerful enough for that material to be traced, as it would have been very dilute in the atmosphere. But the impact would have had regional effects; for example, any sea creatures unlucky enough to be swimming nearby would have been instantly vaporised.

Other candidate double impact craters include Clearwater East and West in Quebec, Canada; Kamensk and Gusev in southern Russia; and Ries and Stenheim in southern Germany.

Source: BBC News

Saturn’s Largest Moon Would Host Really, Really Weird Life

Ah, Titan. Saturn’s largest, haziest moon had a brief starring role in last night’s Cosmos: A Spacetime Odyssey. Toward the end of the episode, Neil DeGrasse Tyson eases his spaceship into one of the moon’s dark, oily seas. He wanted to see what was down there—more specifically, what kind of life might be down there.

After spending most of an hour describing the evolution of life on Earth, it was time to turn toward alien terrains and chemistries—to a place that, while not so very far away, could host some very, very strange lifeforms.

“There’s a world I want to take you to, a world far different from our own, but one that may harbor life. If it does, it promises to be unlike anything we’ve ever seen before,” Tyson says, in the episode.

Titan is deceptively Earth-like. It has a thick, nitrogen atmosphere. Seasonal rainstorms produce wet patches that are visible from orbit. It has lakes. In fact, Titan is the only place in the solar system, besides Earth, with stable liquids on its surface. Those liquids flow through rivers and streams, pool into lakes and seas, sculpt shorelines and surround islands, just like on Earth.

But Titan’s puddles aren’t filled with water—the moon is soaked in hydrocarbons. Methane and ethane, compounds that are gassy on Earth, are liquid on Titan’s frigid surface. Here, temperatures hover around -179 Celsius (or -290 Fahrenheit). It’s so cold that water ice is rock-hard—in fact, the rocks littering the moon’s surface are made from water. Water is everywhere on Titan, but it’s locked in a state that’s inaccessible for life-sustaining chemistries.

Ask an astrobiologist about the prospect of finding life on Titan, and they’ll say the shrouded, orange moon is the place to go if you’re looking for bizarre life. Life that’s not at all like what we know on Earth. Life that, instead of being water-based, uses those slick, liquid hydrocarbons as a solvent. Life that, if we find it, would demonstrate a second genesis—a second origin—and be suggestive of the ease with which life can populate the cosmos.

Life that’s worth taking a chance to find?

“We will never know if liquid water is the only special solvent in which life can form and propagate unless we go and sample these damn lakes and seas,” planetary scientist Jonathan Lunine of Cornell University said during a recent astrobiology conference. Lunine has spent years studying Titan; at one point, he and his colleagues designed a spacecraft that could land on the moon and float in one of its hydrocarbon seas [pdf].

Thinking about life on Titan isn’t new. In the 1970s, Carl Sagan and chemist Bishun Khare, then at Cornell University, were already publishing papers describing the organic chemistry that might be taking place on the Saturnian moon. At that point, though, the large bodies of liquid on the moon’s surface hadn’t yet been spotted, so Sagan and Khare were thinking about the types of reactions that might be taking place in the moon’s atmosphere (in 1982, Sagan and Stanley Dermott proposed that such lakes might exist). Later, Sagan and Khare would show it was possible to make amino acids using the elements found in the moon’s haze.

In the 1990s, the Hubble space telescope offered hints of a wet world, but it wouldn’t be until NASA’s Cassini mission that scientists got a good look at the moon. In 2004, the spacecraft began peering beneath Titan’s cloudy shroud; in 2005, Cassini sent the Huygens probe parachuting through the haze to a spot on Titan’s equator. Data sent back to Earth revealed a world that looks very much like ours—just with a completely different chemistry.

What that different chemistry means for the possibility of life is still speculative.

“Think about life on Earth—we’re all either in water or we’re fancy bags of water,” says astrobiologist Kevin Hand of the Jet Propulsion Laboratory. “On Titan, life in the lakes would be ‘bags’ of liquid methane and/or ethane. That 90[Kelvin] liquid would be the solvent and then whatever is dissolved into the lakes would be the material that’s used to build the other components needed for life, and to power metabolism.”

Powering metabolism is tricky at those temperatures, though, which is one of the reasons why some scientists are hesitant to focus on sending a probe to Titan. Nonetheless, astrobiologists are studying the reactions and pathways that life might use to gain some traction on Titan—including things like breathing hydrogen and eating acetylene.

“Which elements are easy and which elements are hard to access if you’re a ‘weird’ microbe living in Titan’s lakes?” Hand says. “At this point we don’t really know—work is ongoing.”

I had a few questions after watching the Cosmos depiction of Titan’s alien seas. First, if I were a weird life form on Titan, would I be able to see Saturn through Titan’s hundreds of kilometers of haze? Or would the most spectacular planetscape in the solar system be hidden behind that smoggy curtain?

“Even with the human eye, Saturn would be visible as a faint, bright-ish blob in the nighttime haze,” Lunine says. “And if you have eyes that extend even a bit beyond human sight into the nearest part of the infrared, the ringed world would be clearly seen floating ethereally in the skies of Titan.”

Phew.

Second, the scene with Tyson in the spacecraft shows a craggy, chaotic seafloor, with things that look like hydrothermal vents. How much do we really know about Titan’s seafloors?

Turns out, we know quite a lot about Titan’s seashores, and slightly less about its seafloors. Until now, scientists had mostly used seashore shapes and surrounding topography to infer what the seafloors might be like. But in May 2013, Lunine and his colleagues aimed the Cassini spacecraft’s radar at the depths of Ligeia Mare, the second largest sea on Titan (Kraken Mare, which Tyson took a swim in, is the largest). Using the radar data, the team created a map of the sea’s floor—its bathymetry—and saw that Ligeia Mare plunges to a depth of 160 meters (524 feet). The northern seabed is gentler and smoother than the southern, which is riven with flooded valleys and punctuated by steep peaks.

Getting the depth profile meant that scientists could estimate how much liquid hydrocarbon rests in Ligeia Mare: As much as 100 times more than the oil and gas reserves on Earth combined.

Next up? Peering into the depth of Kraken Mare, which covers an area of at least 400,000 square kilometers, or approximately equal to the size of Germany. “Kraken appears to consist of no fewer than three distinct basins, each about the size of Ligeia Mare,” Lunine says. “So there’s a lot of sea to see on Titan.”

Source: NATIONAL GEOGRAPHIC