- UCSB superconducting qubit array points the way to quantum supercomputers (LATEST) 04-23-2014
A new five-qubit array from UCSB’s Martinis Group is on the threshold of making a quantum computer technologically feasible to build A fully functional quantum supercomputer is one of the holy grails of physics. Unlike conventional supercomputers, the quantum version uses qubits (quantum bits), which make direct use of the multiple...
- U of U software identifies disease-causing mutations in undiagnosed illnesses (LATEST) 04-23-2014
A computational tool developed at the University of Utah (U of U) has successfully identified diseases with unknown gene mutations in three separate cases, U of U researchers and their colleagues report in a new study in The American Journal of Human Genetics. The software, Phevor (Phenotype Driven Variant Ontological Re-ranking...
- Bioinformatics profiling identifies a new mammalian clock gene (LATEST) 04-22-2014
'Big data' approach quickens search for human genes related to control of daily biological rhythms Over the last few decades researchers have characterized a set of clock genes that drive daily rhythms of physiology and behavior in all types of species, from flies to humans. Over 15 mammalian clock proteins have been identified,...
- NCAR, CU Join Intel Parallel Computing Centers Program (LATEST) 04-22-2014
The National Center for Atmospheric Research (NCAR) and the University of Colorado Boulder (CU-Boulder) announced today that they will join the Intel Parallel Computing Centers program. Participants in the program will develop methods to increase the performance of applications that use advanced microprocessor technologies and will help...
- Mysteries of a nearby planetary system's dynamics now are solved (LATEST) 04-22-2014
Mysteries of one of the most fascinating nearby planetary systems now have been solved, report authors of a scientific paper to be published by the journal Monthly Notices of the Royal Astronomical Society in its early online edition on 22 April 2014. The study, which presents the first viable model for the planetary system...
- Simulating in tiny steps gave birth to long-sought-after method (LATEST) 04-22-2014
Using supercomputer simulations to predict which drug candidates offer the greatest potential has thus far not been very reliable, because both small drug-like molecules and the amino acids of proteins vary so much in their chemistry. Uppsala researchers have now cunningly managed to develop a method that has proven to be precise,...
- Computational method dramatically speeds up estimates of gene expression (LATEST) 04-22-2014
Method developed by CMU and UMD could pay dividends as genomic medicine expands With gene expression analysis growing in importance for both basic researchers and medical practitioners, researchers at Carnegie Mellon University and the University of Maryland have developed a new computational method that dramatically speeds up...
- Big data poses great opportunities (LATEST) 04-22-2014
Advances in the technology frontier have resulted in major disruptions and transformations in the massive data processing infrastructures. For the past three decades, classical database management systems, data warehousing and data analysis technologies have been well recognized as effective tools for data management and analysis....
- Researchers reconstruct Pacific storm track in climate model (LATEST) 04-17-2014
Model-within-a-model improves accuracy of global simulation of clouds, weather The first study that combines different scales — cloud-sized and earth-sized — in one model to simulate the effects of Asian pollution on the Pacific storm track shows that Asian pollution can influence weather over much of the world. The results show...
- At the origin of cell division (LATEST) 04-16-2014
The features of living matter emerge from inanimate matter Droplets of filamentous material enclosed in a lipid membrane: these are the models of a "simplified" cell used by the SISSA physicists Luca Giomi and Antonio DeSimone, who simulated the spontaneous emergence of cell motility and division - that is, features of living...
- Progress in the fight against quantum dissipation (LATEST) 04-16-2014
Scientists at Yale have confirmed a 50-year-old, previously untested theoretical prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. They report their results in the April 17 issue of the journal Nature. High-quality quantum switches are essential for the development of...
- A*STAR researchers propose network-based evaluation tool to assess relief operations feasibility (LATEST) 04-16-2014
The United Nations Office for Disaster Risk Reduction reported that disasters have affected around 2.9 billion people worldwide from 2000-2012— killing more than a million, and damaging around 1.7 trillion US dollars in estimates. Moreover, natural disasters and their damages have been documented to occur with increasing intensity. Given the...
- NEC selects Chelsio for vector supercomputer (LATEST) 04-16-2014
Chelsio Communications has announced that its T4 based 10GbE adapters have been selected by NEC Corporation for NEC's HPC Systems for network and storage connectivity in SX-ACE, the latest SX-series Vector Supercomputer, targeted at large data processing applications. Equipped with the Chelsio T420-CR Storage Adapter, the NEC...
- Verizon Deploys 100G Technology on Metro Network (LATEST) 04-15-2014
To improve network efficiency and meet continued bandwidth demand, Verizon is deploying 100G technology on its U.S. metro network.The company will gain the same benefits of increased capacity, superior latency and improved scalability in its metro network as it has from deploying 100G technology in its long-haul network.Verizon is...
- Earthquake simulation tops one quadrillion flops: Computational record on SuperMUC (LATEST) 04-15-2014
A team of computer scientists, mathematicians and geophysicists at Technische Universitaet Muenchen (TUM) and Ludwig-Maximillians Universitaet Muenchen (LMU) have – with the support of the Leibniz Supercomputing Center of the Bavarian Academy of Sciences and Humanities (LRZ) – optimized the SeisSol earthquake simulation software on...
- New Context, Chef advance IT automation (LATEST) 04-15-2014
New Context has announced a new partnership with Chef, the leader in web-scale IT automation, to further the goal of enabling business transformation through automation customized to organizations' specific needs. The collaboration is intended to address the need for greater flexibility and adaptability in enterprise IT...
- Quantum manipulation: Filling the gap between quantum and classical world (LATEST) 04-14-2014
Quantum superposition is a fundamental and also intriguing property of the quantum world. Because of superposition, a quantum system can be in two different states simultaneously, like a cat that can be both "dead" and "alive" at the same time. However, this anti-intuitive phenomenon cannot be observed directly, because whenever a...
- Combs of light accelerate communication (LATEST) 04-14-2014
Miniaturized optical frequency comb sources allow for transmission of data streams of several terabits per second over hundreds of kilometers – this has now been demonstrated by researchers of Karlsruhe Institute of Technology (KIT) and the Swiss École Polytechnique Fédérale de Lausanne (EPFL) in a experiment presented in the...
- Cloud leaders enlist ISVs to sell horizontal clouds in vertical markets (LATEST) 04-14-2014
According to Technology Business Research Inc.’s (TBR) 4Q13 Public Cloud Benchmark, public cloud revenue grew 47.4% from the year-ago quarter to $6.2 billion across the 50 vendors covered in the report, while market growth for overall public cloud services grew 25.6% year-to-year over the same period to $15.1 billion. Cost savings,...
- Bailing out the world's fresh water bank (LATEST) 04-14-2014
An Australian-based water scientist is testing a new technology to help save imperilled underground water resources in Australia and around the world as climate change tightens its grip on the global food supply. Dr Margaret Shanafield of the National Centre for Groundwater Research and Training at Flinders University has developed a...
- Published: 03 August 2012
Simulations of the vaporization of Earth-like planets tell planet-hunting astronomers what to look for in the atmospheres of candidate super-Earths.
In science fiction novels, evil overlords and hostile aliens often threaten to vaporize the Earth. At the beginning of The Hitchhikers Guide to the Galaxy, the officiously bureaucratic aliens called Vogons, authors of the third-worst poetry in the universe, actually follow through on the threat, destroying the Earth to make way for a hyperspatial express route.
“We scientists are not content just to talk about vaporizing the Earth,” says Bruce Fegley, professor of earth and planetary sciences at Washington University in St. Louis, tongue firmly in cheek. “We want to understand exactly what it would be like if it happened.”
And in fact Fegley, PhD, and his colleagues Katharina Lodders, PhD, a research professor of earth and planetary sciences who is currently on assignment at the National Science Foundation, and Laura Schaefer, currently a graduate student at Harvard University, have vaporized the Earth — if only by simulation, that is mathematically and inside a computer.
They weren’t just practicing their evil overlord skills. By baking model Earths, they are trying to figure out what astronomers should see when they look at the atmospheres of super-Earths in a bid to learn the planets’ compositions.
Super-earths are planets outside our solar system (exoplanets) that are more massive than Earth but less massive than Neptune and made of rock instead of gas. Because of the techniques used to find them, most of the detected super-Earths are those which orbit close to their stars —within rock-melting distance.
Their NSF- and NASA-funded research, described in the August 10 issue of The Astrophysical Journal, show that Earth-like planets as hot as these exoplanets would have atmospheres composed mostly of steam and carbon dioxide, with smaller amounts of other gases that could be used to distinguish one planetary composition from another.
The WUSTL team is collaborating with Dr. Mark Marley’s research group at the NASA Ames Research Center to convert the gas abundances they have calculated into synthetic spectra the planet hunters can compare to spectra they measure.
Motivated by degeneracy
Under favorable circumstances planet hunting techniques allow astronomers not just to find exoplanets but also to measure their average density.
The average density together with theoretical models lets the astronomers figure out the bulk chemical composition of gas giants, but in the case of rocky planets the possible variety of rocky ingredients can often add up several different ways to the same average density.
This is an outcome scientists, who would prefer one answer per question, call degeneracy.
If a planet passes in front of its star, so that astronomers can observe the light from the star filtered by the planet’s atmosphere, they can determine the composition of the planet’s atmosphere, which allows them to distinguish about alternative bulk planetary compositions.
“It’s not crazy that astronomers can do this and more people are looking at the atmospheres of these transiting exoplanets,” Fegley says. “Right now, there are eight transiting exoplanets where astronomers have done some atmospheric measurements and more will probably be reported in the near future.”
“We modeled the atmospheres of hot super-Earths because that’s what astronomers are finding and we wanted to predict what they should be looking for when they look at the atmospheres to decipher the nature of the planet,” Fegley says.
Two model Earths
Even though the planets are called super-Earths, Fegley says, the term is a reference to their mass and makes no claim about their composition, much less their habitability. But, he says, you start with what you know.
The team ran calculations on two types of pseudo-Earths, one with a composition like that of the Earth’s continental crust and the other, called the BSE (bulk silicate Earth), with a composition like the Earth’s before the continental crust formed, which is the composition of the silicate portion of the primitive Earth before the crust formed.
The difference between the two models, says Fegley, is water. The Earth’s continental crust is dominated by granite, but you need water to make granite. If you don’t have water, you end up with a basaltic crust like Venus. Both crusts are mostly silicon and oxygen, but a basaltic crust is richer in elements such as iron and magnesium.
Fegley is quick to admit the Earth’s continental crust is not a perfect analog for lifeless planets because it has been modified by the presence of life over the past four billion years, which both oxidized the crust and also led to production of vast reservoirs of reduced carbon, for example in the form of coal, natural gas, and oil.
Raining acid and rock
The super-Earths the team used as references are thought to have surface temperatures ranging from about 270 to 1700 degrees Celsius (C), which is about 520 to 3,090 degrees F. The Earth, in contrast, has a global average surface temperature of about 15 degrees C (59 degrees F) and the oven in your kitchen goes up to about 450 Fahrenheit.
Using thermodynamic equilibrium calculations, the team determined which elements and compounds would be gaseous at these alien temperatures.
“The vapor pressure of the liquid rock increases as you heat it, just as the vapor pressure of water increases as you bring a pot to boil,” Fegley says. “Ultimately this puts all the constituents of the rock into the atmosphere.”
The continental crust melts at about 940 C (1,720 F), Fegley says, and the bulk silicate Earth at roughly 1730 C (3,145 F). There are also gases released from the rock as it heats up and melts.
Their calculations showed that the atmospheres of both model Earths would be dominated over a wide temperature range by steam (from vaporizing water and hydrated minerals) and carbon dioxide (from vaporizing carbonate rocks).
The major difference between the models is that the BSE atmosphere is more reducing, meaning that it contains gases that would oxidize if oxygen were present. At temperatures below about 730 C (1,346 F) the BSE atmosphere, for example, contains methane and ammonia.
That’s interesting, Fegley says, because methane and ammonia, when sparked by lighting, combine to form amino acids, as they did in the classic Miller-Urey experiment on the origin of life.
At temperatures above about 730 C, sulfur dioxide would enter the atmosphere, Fegley says. “Then the exoplanet’s atmosphere would be like Venus’s, but with steam,” Fegley says.
The gas most characteristic of hot rocks, however, is silicon monoxide, which would be found in the atmospheres of both types of planets at temperatures of 1,430 C (2,600 F) or higher.
This leads to amusing possibility that as frontal systems moved through this exotic atmosphere, the silicon monoxide and other rock-forming elements might condense and rain out as pebbles.
Asked whether his team ever cranked the temperature high enough to vaporize the entire Earth, not just the crust and the mantle, Fegley admits that they did.
“You’re left with a big ball of steaming gas that’s knocking you on the head with pebbles and droplets of liquid iron,” he says. “But we didn’t put that into the paper because the exoplanets the astronomers are finding are only partially vaporized,” he says.