The University of Colorado's shape-shifting material.

 

Science Over the Edge

A Roundup of Strange Science for the Month

September/October 2018

In the News:

Shape-Shifting Material Can Morph, Reverse Itself Using Heat, Light - A new material developed by University of Colorado Boulder engineers can transform into complex, pre-programmed shapes via light and temperature stimuli, allowing a literal square peg to morph and fit into a round hole before fully reverting to its original form. The controllable shape-shifting material, described today in the journal Science Advances, could have broad applications for manufacturing, robotics, biomedical devices and artificial muscles. "The ability to form materials that can repeatedly oscillate back and forth between two independent shapes by exposing them to light will open up a wide range of new applications and approaches to areas such as additive manufacturing, robotics and biomaterials", said Christopher Bowman, senior author of the new study and a Distinguished Professor in CU Boulder's Department of Chemical and Biological Engineering (CHBE). Previous efforts have used a variety of physical mechanisms to alter an object's size, shape or texture with programmable stimuli. However, such materials have historically been limited in size or extent and the object state changes have proven difficult to fully reverse. The new CU Boulder material achieves readily programmable two-way transformations on a macroscopic level by using liquid crystal elastomers (LCEs), the same technology underlying modern television displays. The unique molecular arrangement of LCEs make them susceptible to dynamic change via heat and light.

Discovery Of Two New Chinese Dinosaurs By International Research Team - Professor Jonah Choiniere from the University of the Witwatersrand, Johannesburg, South Africa was a leading member of the team and is a co-author on the research. The dinosaurs are both alvarezsaurs, an enigmatic group of theropod [meat-eating] dinosaurs, which have many similarities with birds and which show adaptations thought to be related to eating insects that live in colonies. "Alvarezsaurs are weird animals," said Choiniere. "With their strong, clawed hands and weak jaws, they appear to be the dinosaurian analogue to today's aardvarks and anteaters." But alvarezsaurs did not originally eat insects. The earliest members of the group had more typically meat-eating teeth and hands, useful for catching small prey. Only later-evolving members reduced their teeth and evolved a hand with a huge, single claw capable - perhaps - of tearing open rotting logs and anthills. "The new fossils have long arms, and so show that alvarezsaurs evolved short arms only later in their evolutionary history, in species with small body sizes. This is quite different to what happens in the classic example of tyrannosaurs, which have short arms and giant size," said co-author Professor Roger Benson of Oxford University. Bannykus and Xiyunykus are important because they show transitional steps in the process of alvarezsaurs adapting to new diets.

Neandertal Mother, Denisovan Father! - Together with their sister group the Neandertals, Denisovans are the closest extinct relatives of currently living humans. "We knew from previous studies that Neandertals and Denisovans must have occasionally had children together", says Viviane Slon, researcher at the MPI-EVA and one of three first authors of the study. "But I never thought we would be so lucky as to find an actual offspring of the two groups." The ancient individual is only represented by a single small bone fragment. "The fragment is part of a long bone, and we can estimate that this individual was at least 13 years old", says Bence Viola of the University of Toronto. The bone fragment was found in 2012 at Denisova Cave (Russia) by Russian archaeologists. It was brought to Leipzig for genetic analyses after it was identified as a hominin bone based on its protein composition. "An interesting aspect of this genome is that it allows us to learn things about two populations - the Neandertals from the mother's side, and the Denisovans from the father's side", explains Fabrizio Mafessoni from the MPI-EVA who co-authored the study. The researchers determined that the mother was genetically closer to Neandertals who lived in western Europe than to a Neandertal individual that lived earlier in Denisova Cave. This shows that Neandertals migrated between western and eastern Eurasia tens of thousands of years before their disappearance. Analyses of the genome also revealed that the Denisovan father had at least one Neandertal ancestor further back in his family tree. "So from this single genome, we are able to detect multiple instances of interactions between Neandertals and Denisovans", says Benjamin Vernot from the MPI-EVA, the third co-author of the study. "It is striking that we find this Neandertal/Denisovan child among the handful of ancient individuals whose genomes have been sequenced", adds Svante Pääbo, Director of the Department of Evolutionary Genetics at the MPI-EVA and lead author of the study. "Neandertals and Denisovans may not have had many opportunities to meet. But when they did, they must have mated frequently - much more so than we previously thought."

Bringing Salvaged Wooden Ships And Artifacts Back To Life With 'Smart' Nanotech - Thousands of shipwrecks litter the seafloor all over the world, preserved in sediments and cold water. But when one of these ships is brought up from the depths, the wood quickly starts deteriorating. Today, scientists report a new way to use "smart" nanocomposites to conserve a 16th-century British warship, the Mary Rose, and its artifacts. The new approach could help preserve other salvaged ships by eliminating harmful acids without damaging the wooden structures themselves. The Mary Rose sank in 1545 off the south coast of England and remained under the seabed until she was salvaged in 1982, along with over 19,000 artifacts and pieces of timber. While buried in the seabed, sulfur-reducing marine bacteria migrated into the wood of the Mary Rose and produced hydrogen sulfide. This gas reacted with iron ions from corroded fixtures like cannons to form iron sulfides. Although stable in low-oxygen environments, sulfur rapidly oxidizes in regular air in the presence of iron to form destructive acids. Researchers' goals were to avoid acid production by removing the free iron ions. Once raised from the seabed, the ship was sprayed with cold water, which stopped it from drying out and prevented further microbial activity. The conservation team then sprayed the hull with different types of polyethylene glycol (PEG), a common polymer with a wide range of applications, to replace the water in the cellular structure of the wood and strengthen its outer layer. Scientists at the University of Glasgow are devising a new family of tiny magnetic nanoparticles to aid in this process, in collaboration with Schofield and Rachel O'Reilly, Ph.D., at the University of Warwick. In their initial step, the team used synchrotron techniques to probe the nature of the sulfur species before turning the PEG sprays off, and then periodically as the ship dried. This was the first real-time experiment to closely examine the evolution of oxidized sulfur and iron species. This accomplishment has informed efforts to design new targeted treatments for the removal of these harmful species from the Mary Rose wood. The next step will be to use a nanocomposite based on core magnetic iron oxide nanoparticles that include agents on their surfaces that can remove the ions. The nanoparticles can be directly applied to the porous wood structure and guided to particular areas of the wood using external magnetic fields, a technique previously demonstrated for drug delivery. The nanocomposite will be encompassed in a heat-responsive polymer that protects the nanoparticles and provides a way to safely deliver them to and from the wood surface. A major advantage of this approach is that it allows for the complete removal of free iron and sulfate ions from the wood, and these nanocomposites can be tuned by tweaking their surfaces.

Laser Breakthrough Has Physicists Close To Cooling Down Antimatter - For the first time, physicists at CERN have observed a benchmark atomic energy transition in anithydrogen, a major step toward cooling and manipulating the basic form of antimatter. "The Lyman-alpha transition is the most basic, important transition in regular hydrogen atoms, and to capture the same phenomenon in antihydrogen opens up a new era in antimatter science," said Takamasa Momose, the University of British Columbia chemist and physicist who led the development of the laser system used to manipulate the anithydrogen. "This approach is a gateway to cooling down antihydrogen, which will greatly improve the precision of our measurements and allow us test how antimatter and gravity interact, which is still a mystery." Antimatter, annihilated on impact with matter, is notoriously tricky to capture and work with. But its study is key to solving one of the great mysteries of the universe: why anti-matter, which should have existed in equal amounts to matter at the time of the Big Bang, has all but disappeared. "This gets us just a bit closer to answering some of these big questions in physics," said Makoto Fujiwara, Canada's spokesperson for CERN's ALPHA antihydrogen research collaboration, and a physicist with TRIUMF, Canada's particle accelerator centre. "Over the past decades, scientists have been able to revolutionize atomic physics using optical manipulation and laser cooling, and with this result we can begin applying the same tools to probing the mysteries of antimatter." The so-called Lyman-alpha transition, first seen in hydrogen more than 100 years ago, is measured as a series of ultraviolet emissions when a hydrogen atom's electron is prompted to shift from a low orbital to a high orbital. Using laser pulses lasting nano seconds, Momose, Fujiwara, Canadian colleagues, and the international ALPHA collaboration at CERN, were able to achieve the same transition in several hundred antihydrogen atoms magnetically trapped in a vacuum.

Science Quote of the Month - “Bad times have a scientific value. These are occasions a good learner would not miss." - Ralph Waldo Emerson

 

What's New at the Museum:

Them Bones: A Visit to the Capuchin Crypt - Rome is a city of marvelous history, art and architecture: The Coliseum, the Roman Forum, and Saint Peters Basilica to name a few. However, nothing in the city rivals one site for its macabre display: The Capuchin Crypt, where thousands of human bones have been arranged in a morbid tableau. - Full Story

Mysterious Picture of the Month - What is this?

Ask the Curator:

The BIG CRUNCH -What is the Big Crunch and when will it occur? - Madison

The "Big Crunch" is one of several theories about how the universe will end. Probably everybody is now familiar with the leading theory about how the universe started, the so called "Big Bang." According to the Big Bang theory, at the beginning of the universe all matter and energy was compressed into an infinity small point with infinite density and temperature. Then followed a period of rapid inflation and expansion (the Bang). Matter in the universe cooled and coalesced into stars, planets and galaxies. The expansion continues today as each of the local groups of galaxies, including ours, grows further apart from each other.

For many years scientists pondered what would happen at the end of the universe. While the expansion continues, gravity is trying to reverse the process and pull all matter back together. Scientists figured that either gravity would be too weak and the expansion would continue forever while just getting slower and slower, or gravity would be strong enough to bring all the matter and energy back together in a "Big Crunch."

Scientists also speculated if the universe did come back into a "Big Crunch" it might precipitate another "Big Bang" which would create another universe. Ours, they suggested, might be just one in an unending series of universes.

Initial measurements suggested the amount of gravity and the speed of the expansion were very nearly balanced. This meant that scientists had to impatiently wait for decades until better technology was available so that more accurate studies could be made and they could find out what the fate of the universe was.

In one of those moments that proved that Sir Arthur Eddington was right when he said "not only is the universe stranger than we imagine, it is stranger than we can imagine," the results came back showing that the expansion wasn't slowing at all. It was - much to the shock of almost everybody - accelerating. Scientists have decided that the reason for the acceleration must be something they've dubbed "dark energy," but they have almost no idea what this energy might be and how it works.

If the expansion continues at the current rate the universe may end in "The Big Rip." At some point about 50 billion years in the future the expansion will become so great that everything will be ripped apart. Galaxies will fly apart as individual solar systems go their own way. Later stars will lose their planets and eventually everything down to the subatomic level will be torn asunder.

Although a "Big Crunch" seems unlikely due to this most recent finding, because scientists know almost nothing about what "dark energy" is, they can't rule out that it might suddenly reverse and cause a rapid collapse of the universe. When this might happen is also a mystery. If there is a Big Crunch, the universe would end as all matter was sucked into black holes, then the black holes were pulled together to create a single massive black hole. Scientists have no idea whether this singularity might lead to a new universe and a new expansion or not.

 

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In History:

First U.S. Nuclear Plant - On September 6th of 1954, the ground was broken at Shippingport, Pennsylvania, for the first U.S. full-scale atomic power reactor devoted non-military uses. When completed the reactor at full power had a capacity of 60 megawatts and could supply a city of 250,000 homes. The system used a single pressurized water-type reactor which heated steam that would drive an electrical turbine-generator.

 

In the Sky:

A Glimpse of Neptune - The planet Neptune is too faint to be glimpsed with the naked eye, but this month you might just be able to spot it using a pair of binoculars. Neptune comes into opposition - when it is nearest the Earth - on the 7th of September. It should be easily seen through binoculars sitting in the constellation Aquarius over to the left of the star Lambda Aquarii. You may need a star chart to find this constellation if you are unfamiliar with it.

 

Observed:

Man Bags Giant Gator - A South Florida resident named Jim Howard hunted and killed a 1,000, 12 foot long alligator in Lake Okeechobee, Florida, during a contest. Howard, who works as an airline pilot, is described by his daughter as "crazy and a badass all at the same time." After hooking the massive gator, Howard had assistance from two friends in bringing it in close enough to his boat that he could dispatch it with a shotgun shell in a "bang stick" to the head. Despite the size the gator was not the longest ever caught. That was a 14 footer killed in 2010.

 

LGM:

Zeep and Meep are on a well deserved vacation. In their place we feature highlights from their past adventures.

Science over the Edge Archives

LGM Archive 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014

Copyright Lee Krystek 2018. All Rights Reserved.

 

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