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  • richardmitnick 7:38 am on March 13, 2019 Permalink | Reply
    Tags: "Old stone walls record the changing location of magnetic North", , , , Geomagnetism, The Conversation   

    From The Conversation: “Old stone walls record the changing location of magnetic North” 

    Conversation
    From The Conversation

    March 12, 2019
    John Delano

    1
    The orientations of the stone walls that crisscross the Northeastern U.S. can tell a geomagnetic tale as well as a historical one. John Delano, CC BY-ND

    When I was a kid living in southern New Hampshire, my family home was on the site of an abandoned farmstead consisting of massive stone foundations of quarried granite where dwellings once stood. Stone walls snaked throughout the forest. As I explored the deep woods of tall oaks and maples, I wondered about who had built these walls, and why. What stories did these walls contain?

    Decades later, while living in a rural setting in upstate New York and approaching retirement as a geologist, my long dormant interest was rekindled by treks through the neighboring woods. By now I knew that stone walls in New England and New York are iconic vestiges from a time when farmers, in order to plant crops and graze livestock, needed to clear the land of stones. Tons and tons of granite had been deposited throughout the region during the last glaciation that ended about 10,000 years ago.

    By the late 1800s, nearly 170,000 subsistence farming families had built an estimated 246,000 miles of stone walls across the Northeast. But by then, the Industrial Revolution had already started to contribute to the widespread abandonment of these farms in the northeastern United States. They were overgrown by forests within a few decades.

    During my more recent walks through the woods, on a whim I used a hand-held GPS unit to map several miles of stone walls. And that was how I realized that in addition to being part of an American legacy, their locations record a centuries-long history of the Earth’s wandering magnetic field.

    Connecting the walls with historical maps

    The complex array of walls that emerged from my GPS readings made no sense to me until I found an old map of my town’s property boundaries at the local historical society. Suddenly I saw that some of the stone walls on my map lay along property lines from 1790. They marked boundaries.

    My subsequent searches of church records and decades of the federal census revealed the names of these farm families and details of their lives, including annual yields from their harvests. I started to feel like the stone walls were letting me connect with the long-gone folks who had worked this land.

    Now the wheels in my scientist’s mind really started spinning. Did the original land surveys from the 18th and 19th centuries in this part of town still exist? What were the magnetic compass-bearings of those boundaries on the original surveys?

    2
    Historical maps and surveys underscore the orderly way plots were divvied up from the landscape in a grid. Charles Peirce/Stoddard, New Hampshire

    I knew that the location of magnetic north drifts over time due to changes in the Earth’s core. Could I determine its drift using stone walls and the old land surveys? My preliminary map of stone walls and a few historical surveys showed that the approach had potential.

    To have any scientific value, though, this work had to encompass much larger areas. I needed a different strategy for finding and mapping stone walls. Luckily I found two troves of useful information. First, the New York State Archives had hundreds of the original land surveys from the 18th and 19th centuries. And secondly, airborne LiDAR (light detection and ranging) images were publicly available that could reveal stone walls hidden beneath the forest canopy over much larger areas than I could cover on my own by foot.

    3
    Magnetic north and geographic north aren’t the same – and their difference changes over time. Siberian Art/Shutterstock.com

    Tracking magnetic north’s drift over time

    The Earth rotates on its axis once every 24 hours. The location of that spin axis in the Northern Hemisphere is called true north, and wanders very slowly. The location of true north can be considered stationary, though, on a timescale of a few centuries.

    But that’s not where a compass aims when it points north. The location of the north magnetic pole is not only at a different location from true north, but also changes rapidly – currently about one degree per 10 years in New England.

    The difference in direction between true north and magnetic north (at a specific time and location on the Earth) is known as the magnetic declination. Global information about historic variations in magnetic declination is currently based on thousands of magnetic compass-bearings recorded in ships’ navigational logs from 1590 onwards.

    But now my work on 726 miles of stone walls provides an independent check [JGR Solid Earth] on magnetic declination between 1685 and 1910.

    Here’s the logic. When settlers were piling up those stones along the boundaries of their plots, they were using property lines that had been laid out according to the surveyors’ compass readings. Using LiDAR images, the bearings of those stone walls could be determined with respect to true north and compared with the surveyors’ magnetic bearings. The difference is the magnetic declination at the time of the original survey.

    For example, the original surveys divided New Hampshire’s Stoddard township into hundreds of lots with boundaries with magnetic compass-bearings of N80 degrees W and N14 degrees E in 1768. As the land was cleared for farming, owners built stone walls along and within those 1768 surveyed boundaries.

    4
    Lidar reveals the stone walls hidden beneath the canopy. Comparing their orientation with true north provides the magnetic declination at this location when boundaries were surveyed in 1768. CC BY-ND

    Now one can compare the bearings of those stone wall-defined boundaries relative to magnetic north and true north today. The difference shows that the magnetic declination at this location in 1768 was 7.6 ± 0.3 degrees W. That’s a good match for scientists’ current geophysical model. Since the magnetic declination at this location today is 14.2 degrees W, the direction to magnetic north at this location has moved about 6.6 degrees further west since 1768.

    Data from these stone walls strengthen the current geophysical model about the Earth’s magnetic field.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 1:23 am on March 5, 2019 Permalink | Reply
    Tags: Deuterium and tritium- called heavy hydrogen have been used to make hydrogen bombs, Fusion Technology-when burned in a controlled way hydrogen offers the cleanest fuel producing only water as the waste product, , , Protons also are the key component of fuel cells. Rather than burn the hydrogen fuel cells convert it to electricity and are seen as the way of the future. They do this by splitting the hydrogen gas i, The Conversation, With rapid advances in chemistry and engineering hydrogen stations could start to appear soon becoming as commonplace as gasoline filling stations are today.   

    From The Conversation: “Lightweight of periodic table plays big role in life on Earth” 

    Conversation
    From The Conversation

    3.3.19
    Nicholas Leadbeater

    Periodic table Sept 2017. Wikipedia

    Although hydrogen is the lightweight of the chemical elements, it packs a real punch when it comes to its role in life and its potential as a solution to some of the world’s challenges. As we celebrate the 150th anniversary of the periodic table, it seems reasonable to tip our hat to this, the first element on the table.

    1
    One oxygen atom is connected to two hydrogen atoms to make water. Liaskovskaia Ekaterina/SHutterstock.com

    Hydrogen is the most abundant element in the universe, but not on Earth due to its light weight, which allows the gas to just float off into space. Hydrogen is essential to our life – it fuels the sun, which converts hundreds of million tons of hydrogen into helium every second. And two hydrogen atoms are attached to one oxygen atom to make water. Both these things make our planet habitable.

    Not only does hydrogen enable the sun to warm the Earth and help create the water that sustains life, but this simplest of all the elements may also provide the key to finding a clean fuel source to power the planet.

    Hydrogen’s yin and yang as an energy source

    Like many other chemical elements, although hydrogen is of immense value to us, it also has a darker side. Being lighter than air, it makes things float, which is why is was used in early airships. But hydrogen is highly explosive, and in 1937 the German airship the Hindenburg exploded on its attempt to dock with its mooring mast after a transatlantic journey, killing 36 people.

    3
    Isotopes of hydrogen: protium, deuterium and tritium. Designua/Shutterstock.com

    Hydrogen’s cousins, deuterium and tritium, called heavy hydrogen, have been used to make hydrogen bombs. Here, the heavy hydrogen atoms merge together in a process called nuclear fusion to make helium, a bit like the reaction that takes place in the sun. The amount of energy produced by this process is greater than any other known process – the area at the center of the explosion is essentially vaporized, generating shock waves that destroy anything in their way. The bright white light produced can blind people many miles away. It also produces radioactive products that are carried in the air and cause widespread contamination of the environment.

    Taming the beast, however, could be the solution to the energy problems of the future. When burned in a controlled way, hydrogen offers the cleanest fuel, producing only water as the waste product. That’s refreshing when compared with a gasoline engine that produces climate change-inducing carbon dioxide and a range of other nasty gases. When stored under high pressure and very low temperature of -400 degrees Fahrenheit, hydrogen exists as a liquid, and its combustion with oxygen is used for propelling rockets into space.

    However, a car with a tank of highly explosive hydrogen rocket fuel doesn’t sound like a safe bet. There’s currently lots of research focused on solving the storage problem. Large numbers of scientists are trying to develop chemical compounds that safely hold and release hydrogen. This is actually a hard nut to crack and is something that will take time and many great minds to solve.

    The power of hydrogen

    Hydrogen atoms also give things like lemon juice and vinegar their distinctive tart taste. Positively charged hydrogen atoms, called protons, having been stripped of their only electron, float around in these solutions and are the key component of acids. The chemistry of these protons is also responsible for driving photosynthesis, the process whereby plants turn light energy into chemical energy, and powering many processes in the human body.

    3
    This is the symbol and electron diagram for hydrogen. BlueRingMedia/Shutterstock.com

    Protons also are the key component of fuel cells. Rather than burn the hydrogen, fuel cells convert it to electricity and are seen as the way of the future. They do this by splitting the hydrogen gas into protons and electrons on one side of the fuel cell. The positively charged protons move over to the other side of the cell, leaving behind the negatively charged electrons. This creates a flow of electricity between the sides of the cell when connected with an external circuit. This current can power an electric motor placed in this circuit. Hydrogen-powered trains are already in operation in Germany, and several international car manufacturers are developing fuel-cell powered cars. Again, the only byproduct of the process is water.

    In the future, I think we will see increasing use of hydrogen as a fuel. For it to be useful, there are two major challenges. A big one is the storage issue. Engineers need to figure out how to store hydrogen safely and start to build places where people can fill up. With rapid advances in chemistry and engineering, hydrogen stations could start to appear soon, becoming as commonplace as gasoline filling stations are today. This sort of infrastructure is going to be essential. You don’t want run out of fuel on a journey because, unlike a gas-powered car, you can’t call a friend to bring you a canister of hydrogen.

    4
    Hydrogen fuel pump at Shell station, for automobiles running on pollution-free hydrogen-powered fuel cells. Rob Crandall/Shutterstock.com

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 11:04 am on February 23, 2019 Permalink | Reply
    Tags: , , The Conversation, Utilities are starting to invest in big batteries instead of building new power plants   

    From The Conversation: “Utilities are starting to invest in big batteries instead of building new power plants” 

    Conversation
    From The Conversation

    February 22, 2019
    Jeremiah Johnson
    Associate Professor of Environmental Engineering
    North Carolina State University

    Joseph F. DeCarolis
    Associate Professor of Environmental Engineering
    North Carolina State University

    1
    Utilities are starting to invest in big batteries instead of building new power plants. This is what a 5-megawatt, lithium-ion energy storage system looks like. phys.org
    Credit: Pacific Northwest National Laboratory.

    Due to their decreasing costs, lithium-ion batteries now dominate a range of applications including electric vehicles, computers and consumer electronics.

    You might only think about energy storage when your laptop or cellphone are running out of juice, but utilities can plug bigger versions into the electric grid. And thanks to rapidly declining lithium-ion battery prices, using energy storage to stretch electricity generation capacity.

    Based on our research on energy storage costs and performance in North Carolina, and our analysis of the potential role energy storage could play within the coming years, we believe that utilities should prepare for the advent of cheap grid-scale batteries and develop flexible, long-term plans that will save consumers money.

    2
    All of the new utility-scale electricity capacity coming online in the U.S. in 2019 will be generated through natural gas, wind and solar power as coal, nuclear and some gas plants close. U.S. Energy Information Administration

    Peak demand is pricey

    The amount of electricity consumers use varies according to the time of day and between weekdays and weekends, as well as seasonally and annually as everyone goes about their business.

    Those variations can be huge.

    For example, the times when consumers use the most electricity in many regions is nearly double the average amount of power they typically consume. Utilities often meet peak demand by building power plants that run on natural gas, due to their lower construction costs and ability to operate when they are needed.

    However, it’s expensive and inefficient to build these power plants just to meet demand in those peak hours. It’s like purchasing a large van that you will only use for the three days a year when your brother and his three kids visit.

    The grid requires power supplied right when it is needed, and usage varies considerably throughout the day. When grid-connected batteries help supply enough electricity to meet demand, utilities don’t have to build as many power plants and transmission lines.

    Given how long this infrastructure lasts and how rapidly battery costs are dropping, utilities now face new long-term planning challenges.

    3
    Grid-scale batteries are being installed coast-to-coast as this snapshot from 2017 indicates. Source: U.S. Energy Information Administration, U.S. Battery Storage Market Trends, 2018.

    Cheaper batteries

    About half of the new generation capacity built in the U.S. annually since 2014 has come from solar, wind or other renewable sources. Natural gas plants make up the much of the rest but in the future, that industry may need to compete with energy storage for market share.

    In practice, we can see how the pace of natural gas-fired power plant construction might slow down in response to this new alternative.

    So far, utilities have only installed the equivalent of one or two traditional power plants in grid-scale lithium-ion battery projects, all since 2015. But across California, Texas, the Midwest and New England, these devices are benefiting the overall grid by improving operations and bridging gaps when consumers need more power than usual.

    Based on our own experience tracking lithium-ion battery costs, we see the potential for these batteries to be deployed at a far larger scale and disrupt the energy business.

    When we were given approximately one year to conduct a study on the benefits and costs of energy storage in North Carolina, keeping up with the pace of technological advances and increasing affordability was a struggle.

    Projected battery costs changed so significantly from the beginning to the end of our project that we found ourselves rushing at the end to update our analysis.

    Once utilities can easily take advantage of these huge batteries, they will not need as much new power-generation capacity to meet peak demand.

    What energy-storage batteries cost

    Grid-scale lithium-ion battery costs per kilowatt hour have plummeted in the past four years. They will probably fall further.

    Utility planning

    Even before batteries could be used for large-scale energy storage, it was hard for utilities to make long-term plans due to uncertainty about what to expect in the future.

    For example, most energy experts did not anticipate the dramatic decline in natural gas prices due to the spread of hydraulic fracturing, or fracking, starting about a decade ago – or the incentive that it would provide utilities to phase out coal-fired power plants.

    In recent years, solar energy and wind power costs have dropped far faster than expected, also displacing coal – and in some cases natural gas – as a source of energy for electricity generation.

    Something we learned during our storage study is illustrative.

    We found that lithium ion batteries at 2019 prices were a bit too expensive in North Carolina to compete with natural gas peaker plants – the natural gas plants used occasionally when electricity demand spikes. However, when we modeled projected 2030 battery prices, energy storage proved to be the more cost-effective option.

    Federal, state and even some local policies are another wild card. For example, Democratic lawmakers have outlined the Green New Deal, an ambitious plan that could rapidly address climate change and income inequality at the same time.

    And no matter what happens in Congress, the increasingly frequent bouts of extreme weather hitting the U.S. are also expensive for utilities. Droughts reduce hydropower output and heatwaves make electricity usage spike.

    4
    The Scattergood power plant in Los Angeles is one of three natural gas power plants slated to shut down by 2029. AP Photo/Marcio Jose Sanchez

    The future

    Several utilities are already investing in energy storage.

    California utility Pacific Gas & Electric, for example, got permission from regulators to build a massive 567.5 megawatt energy-storage battery system near San Francisco, although the utility’s bankruptcy could complicate the project.

    Hawaiian Electric Company is seeking approval for projects that would establish several hundred megawatts of energy storage across the islands. And Arizona Public Service and Puerto Rico Electric Power Authority are looking into storage options as well.

    We believe these and other decisions will reverberate for decades to come. If utilities miscalculate and spend billions on power plants it turns out they won’t need instead of investing in energy storage, their customers could pay more than they should to keep the lights through the middle of this century.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 2:48 pm on February 7, 2019 Permalink | Reply
    Tags: A massive leap forward in nuclear physics, , Nuclear fission, , , She was excluded from the victory celebration [The Nobel Prize] because she was a Jewish woman, The Conversation, Today Lise Meitner remains obscure and largely forgotten   

    From The Conversation: “Lise Meitner — the forgotten woman of nuclear physics who deserved a Nobel Prize” 

    Conversation
    From The Conversation

    February 7, 2019
    Timothy J. Jorgensen

    Nuclear fission – the physical process by which very large atoms like uranium split into pairs of smaller atoms – is what makes nuclear bombs and nuclear power plants possible. But for many years, physicists believed it energetically impossible for atoms as large as uranium (atomic mass = 235 or 238) to be split into two.

    That all changed on Feb. 11, 1939, with a letter to the editor of Nature – a premier international scientific journal – that described exactly how such a thing could occur and even named it fission. In that letter, physicist Lise Meitner, with the assistance of her young nephew Otto Frisch, provided a physical explanation of how nuclear fission could happen.

    It was a massive leap forward in nuclear physics, but today Lise Meitner remains obscure and largely forgotten.

    3
    Lise Meitner (7 November 1878 – 27 October 1968) Smithsonian Institution

    She was excluded from the victory celebration because she was a Jewish woman. Her story is a sad one.

    What happens when you split an atom

    Meitner based her fission argument on the “liquid droplet model” of nuclear structure – a model that likened the forces that hold the atomic nucleus together to the surface tension that gives a water droplet its structure.

    She noted that the surface tension of an atomic nucleus weakens as the charge of the nucleus increases, and could even approach zero tension if the nuclear charge was very high, as is the case for uranium (charge = 92+). The lack of sufficient nuclear surface tension would then allow the nucleus to split into two fragments when struck by a neutron – a chargeless subatomic particle – with each fragment carrying away very high levels of kinetic energy. Meisner remarked: “The whole ‘fission’ process can thus be described in an essentially classical [physics] way.” Just that simple, right?

    Meitner went further to explain how her scientific colleagues had gotten it wrong. When scientists bombarded uranium with neutrons, they believed the uranium nucleus, rather than splitting, captured some neutrons. These captured neutrons were then converted into positively charged protons and thus transformed the uranium into the incrementally larger elements on the periodic table of elements – the so-called “transuranium,” or beyond uranium, elements.

    Some people were skeptical that neutron bombardment could produce transuranium elements, including Irene Joliot-Curie – Marie Curie’s daughter – and Meitner. Joliot-Curie had found that one of these new alleged transuranium elements actually behaved chemically just like radium, the element her mother had discovered. Joliot-Curie suggested that it might be just radium (atomic mass = 226) – an element somewhat smaller than uranium – that was coming from the neutron-bombarded uranium.

    Meitner had an alternative explanation. She thought that, rather than radium, the element in question might actually be barium – an element with a chemistry very similar to radium. The issue of radium versus barium was very important to Meitner because barium (atomic mass = 139) was a possible fission product according to her split uranium theory, but radium was not – it was too big (atomic mass = 226).

    7
    When a neutron bombards a uranium atom, the uranium nucleus splits into two different smaller nuclei. Stefan-Xp/Wikimedia Commons, CC BY-SA

    Meitner urged her chemist colleague Otto Hahn to try to further purify the uranium bombardment samples and assess whether they were, in fact, made up of radium or its chemical cousin barium. Hahn complied, and he found that Meitner was correct: the element in the sample was indeed barium, not radium. Hahn’s finding suggested that the uranium nucleus had split into pieces – becoming two different elements with smaller nuclei – just as Meitner had suspected.

    As a Jewish woman, Meitner was left behind

    Meitner should have been the hero of the day, and the physicists and chemists should have jointly published their findings and waited to receive the world’s accolades for their discovery of nuclear fission. But unfortunately, that’s not what happened.

    Meitner had two difficulties: She was a Jew living as an exile in Sweden because of the Jewish persecution going on in Nazi Germany, and she was a woman. She might have overcome either one of these obstacles to scientific success, but both proved insurmountable.

    5
    Lise Meitner and Otto Hahn in Berlin, 1913.

    Meitner had been working as Hahn’s academic equal when they were on the faculty of the Kaiser Wilhelm Institute in Berlin together. By all accounts they were close colleagues and friends for many years. When the Nazis took over, however, Meitner was forced to leave Germany. She took a position in Stockholm, and continued to work on nuclear issues with Hahn and his junior colleague Fritz Strassmann through regular correspondence. This working relationship, though not ideal, was still highly productive. The barium discovery was the latest fruit of that collaboration.

    Nuclear fission – the physical process by which very large atoms like uranium split into pairs of smaller atoms – is what makes nuclear bombs and nuclear power plants possible. But for many years, physicists believed it energetically impossible for atoms as large as uranium (atomic mass = 235 or 238) to be split into two.

    That all changed on Feb. 11, 1939, with a letter to the editor of Nature – a premier international scientific journal – that described exactly how such a thing could occur and even named it fission. In that letter, physicist Lise Meitner, with the assistance of her young nephew Otto Frisch, provided a physical explanation of how nuclear fission could happen.

    It was a massive leap forward in nuclear physics, but today Lise Meitner remains obscure and largely forgotten. She was excluded from the victory celebration because she was a Jewish woman. Her story is a sad one.
    What happens when you split an atom

    Meitner based her fission argument on the “liquid droplet model” of nuclear structure – a model that likened the forces that hold the atomic nucleus together to the surface tension that gives a water droplet its structure.

    She noted that the surface tension of an atomic nucleus weakens as the charge of the nucleus increases, and could even approach zero tension if the nuclear charge was very high, as is the case for uranium (charge = 92+). The lack of sufficient nuclear surface tension would then allow the nucleus to split into two fragments when struck by a neutron – a chargeless subatomic particle – with each fragment carrying away very high levels of kinetic energy. Meisner remarked: “The whole ‘fission’ process can thus be described in an essentially classical [physics] way.” Just that simple, right?

    Meitner went further to explain how her scientific colleagues had gotten it wrong. When scientists bombarded uranium with neutrons, they believed the uranium nucleus, rather than splitting, captured some neutrons. These captured neutrons were then converted into positively charged protons and thus transformed the uranium into the incrementally larger elements on the periodic table of elements – the so-called “transuranium,” or beyond uranium, elements.

    Some people were skeptical that neutron bombardment could produce transuranium elements, including Irene Joliot-Curie – Marie Curie’s daughter – and Meitner. Joliot-Curie had found that one of these new alleged transuranium elements actually behaved chemically just like radium, the element her mother had discovered. Joliot-Curie suggested that it might be just radium (atomic mass = 226) – an element somewhat smaller than uranium – that was coming from the neutron-bombarded uranium.

    Meitner had an alternative explanation. She thought that, rather than radium, the element in question might actually be barium – an element with a chemistry very similar to radium. The issue of radium versus barium was very important to Meitner because barium (atomic mass = 139) was a possible fission product according to her split uranium theory, but radium was not – it was too big (atomic mass = 226).
    When a neutron bombards a uranium atom, the uranium nucleus splits into two different smaller nuclei. Stefan-Xp/Wikimedia Commons, CC BY-SA

    Meitner urged her chemist colleague Otto Hahn to try to further purify the uranium bombardment samples and assess whether they were, in fact, made up of radium or its chemical cousin barium. Hahn complied, and he found that Meitner was correct: the element in the sample was indeed barium, not radium. Hahn’s finding suggested that the uranium nucleus had split into pieces – becoming two different elements with smaller nuclei – just as Meitner had suspected.
    As a Jewish woman, Meitner was left behind

    Meitner should have been the hero of the day, and the physicists and chemists should have jointly published their findings and waited to receive the world’s accolades for their discovery of nuclear fission. But unfortunately, that’s not what happened.

    Meitner had two difficulties: She was a Jew living as an exile in Sweden because of the Jewish persecution going on in Nazi Germany, and she was a woman. She might have overcome either one of these obstacles to scientific success, but both proved insurmountable.

    Meitner had been working as Hahn’s academic equal when they were on the faculty of the Kaiser Wilhelm Institute in Berlin together. By all accounts they were close colleagues and friends for many years. When the Nazis took over, however, Meitner was forced to leave Germany. She took a position in Stockholm, and continued to work on nuclear issues with Hahn and his junior colleague Fritz Strassmann through regular correspondence. This working relationship, though not ideal, was still highly productive. The barium discovery was the latest fruit of that collaboration.

    Yet when it came time to publish, Hahn knew that including a Jewish woman on the paper would cost him his career in Germany. So he published without her, falsely claiming that the discovery was based solely on insights gleaned from his own chemical purification work, and that any physical insight contributed by Meitner played an insignificant role. All this despite the fact he wouldn’t have even thought to isolate barium from his samples had Meitner not directed him to do so.

    Hahn had trouble explaining his own findings, though. In his paper, he put forth no plausible mechanism as to how uranium atoms had split into barium atoms. But Meitner had the explanation. So a few weeks later, Meitner wrote her famous fission letter to the editor, ironically explaining the mechanism of “Hahn’s discovery.”

    Even that didn’t help her situation. The Nobel Committee awarded the 1944 Nobel Prize in Chemistry “for the discovery of the fission of heavy nuclei” to Hahn alone. Paradoxically, the word “fission” never appeared in Hahn’s original publication, as Meitner had been the first to coin the term in the letter published afterward.

    A controversy has raged about the discovery of nuclear fission ever since, with critics claiming it represents one of the worst examples of blatant racism and sexism by the Nobel committee. Unlike another prominent female nuclear physicist whose career preceded her – Marie Curie – Meitner’s contributions to nuclear physics were never recognized by the Nobel committee. She has been totally left out in the cold, and remains unknown to most of the public.

    6
    Meitner received the Enrico Fermi Award in 1966. Her nephew Otto Frisch is on the left. IAEA, CC BY-SA

    After the war, Meitner remained in Stockholm and became a Swedish citizen. Later in life, she decided to let bygones be bygones. She reconnected with Hahn, and the two octogenarians resumed their friendship. Although the Nobel committee never acknowledged its mistake, the slight to Meitner was partly mitigated in 1966 when the U.S. Department of Energy jointly awarded her, Hahn and Strassmann its prestigious Enrico Fermi Award “for pioneering research in the naturally occurring radioactivities and extensive experimental studies leading to the discovery of fission.” The two-decade late recognition came just in time for Meitner. She and Hahn died within months of each other in 1968; they were both 89 years old.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 1:21 pm on December 16, 2018 Permalink | Reply
    Tags: Huge previously-undetected coral reef off US East Coast, , The Conversation   

    From The Conversation: “Deepwater corals thrive at the bottom of the ocean, but can’t escape human impacts” 

    Conversation
    From The Conversation

    December 3, 2018
    Sandra Brooke

    When people think of coral reefs, they typically picture warm, clear waters with brightly colored corals and fishes. But other corals live in deep, dark, cold waters, often far from shore in remote locations. These varieties are just as ecologically important as their shallow water counterparts. They also are just as vulnerable to human activities like fishing and energy production.

    7
    Deep sea corals off Florida. Image via NOAA.

    Earlier this year I was part of a research expedition conducted by the Deep Search project, which is studying little-known deep-sea ecosystems off the southeast U.S. coast. We were exploring areas that had been mapped and surveyed by the U.S. National Oceanic and Atmospheric Administration’s research ship Okeanos.

    1
    Map of target areas to be surveyed during the first phase of the Deepwater Atlantic Habitats II study, DEEP SEARCH, including seep targets. USGS image.

    2
    NOAA Ship Okeanos Explorer

    NOAA Ship Okeanos Explorer is the only federal vessel dedicated to exploring our largely unknown ocean for the purpose of discovery and the advancement of knowledge about the deep ocean. The ship is operated by the NOAA Commissioned Officer Corps and civilians as part of NOAA’s fleet managed by NOAA’s Office of Marine and Aviation Operations. Mission equipment is operated by NOAA’s Office of Ocean Exploration and Research in partnership with the Global Foundation for Ocean Exploration .

    Missions of the 224-foot vessel include mapping, site characterization, reconnaissance, advancing technology, education, and outreach—all focused on understanding, managing, and protecting our ocean. Expeditions are planned collaboratively, with input from partners and stakeholders, and with the goal of providing data that will benefit NOAA, the scientific community, and the public.

    During Okeanos Explorer expeditions, data are collected using a variety of advanced technologies to explore and characterize unknown or poorly known deepwater ocean areas, features, and phenomena at depths ranging from 250 to 6,000 meters (820 to 19,700 feet). The ship is equipped with four different types of mapping sonars that collect high-resolution data about the seafloor and the water column, a dual-body remotely operated vehicle (ROV) capable of diving to depths of 6,000 meters, and a suite of other instruments to help characterize the deep ocean. Expeditions typically consist of either 24-hour mapping operations or a combination of daytime ROV dives and overnight mapping operations.

    In an area 160 miles off South Carolina we deployed Alvin, a three-person research submersible, to explore some features revealed during the mapping.

    4
    Human Occupied Vehicle (HOV) Alvin is part of the National Deep Submergence Facility (NDSF). Alvin enables in-situ data collection and observation by two scientists to depths reaching 4,500 meters, during dives lasting up to ten hours.

    What the scientists aboard Alvin found was a huge “forest” of coldwater corals. I went down on the second dive in this area and saw another dense coral ecosystem. These were just two features in a series that covered about 85 miles, in water nearly 2,000 feet deep. This unexpected find shows how much we still have to learn about life on the ocean floor.


    Scientists from the August 2018 Deep Search expedition discuss the significance of finding a huge, previously undetected deepwater coral reef off the U.S. East Coast.

    Life in the dark

    Deep corals are found in all of the world’s oceans. They grow in rocky habitats on the seafloor as it slopes down into the deep oceans, on seamounts (underwater mountains), and in submarine canyons. Most are found at depths greater than 650 feet (200 meters), but where surface waters are very cold, they can grow at much shallower depths.

    Shallow corals get much of their energy from sunlight that filters down into the water. Like plants on land, tiny algae that live within the corals’ polyps use sunlight to make energy, which they transfer to the coral polyps. Deep-sea species grow below the sunlit zone, so they feed on organic material and zooplankton, delivered to them by strong currents.

    In both deep and shallow waters, stony corals – which create hard skeletons – are the reef builders, while others such as soft corals add to reef diversity. Just five deep-sea stony coral species create reefs like the one we found in August.

    6
    Stylaster californicus at 135 feet depth on Farnsworth Bank off southern California. NOAA

    The most widely distributed and well-studied is Lophelia pertusa, a branching stony coral that begins life as a tiny larva, settles on hard substrate and grows into a bushy colony.

    6
    Lophelia pertusa

    As the colony grows, its outside branches block the flow of water that delivers food and oxygen to inner branches and washes away waste. Without flow, the inner branches die and weaken, then break apart, and the outer live branches overgrow the dead skeleton.

    This sequence of growth, death, collapse, and overgrowth continues for thousands of years, creating reefs that can be hundreds of feet tall. These massive, complex structures provide habitat for diverse and abundant assemblages of invertebrates and fishes, some of which are economically valuable.

    Other important types include gorgonians and black corals, often called “tree corals.” These species can grow very large and form dense “coral gardens” in rocky, current-swept areas. Small invertebrates and fishes use their branches for shelter, feeding and nursery habitat.

    Probing the deep oceans

    Organisms that live in deep, cold waters grow slowly, mature late and have long lifespans. Deep-sea black corals are among the oldest animals on earth: One specimen has been dated at 4,265 years old. As they grow, corals incorporate ocean elements into their skeletons. This makes them archives of ocean conditions that long predate human records. They also can provide valuable insights into the likely effects of future changes in the oceans.

    To protect these ecosystems, scientists need to find them. This is challenging because most of the seafloor has not been mapped. Once they have maps, researchers know where to deploy underwater vehicles so they can begin to understand how these ecosystems function.

    Scientists use submersibles like Alvin or remotely operated vehicles to study deep-water corals because other gear, such as trawls and dredges, would become entangled in these fragile colonies and damage them. Submersibles can take visual surveys and collect samples without impacting reefs.

    7
    The NOAA ROV Deep Discoverer documents benthic communities at Paganini Seamount in the north-central Pacific. NOAA

    This work is expensive and logistically challenging. It requires large ships to transport and launch the submersibles, and can only be done when seas are calm enough to work.

    Looming threats

    The greatest threat to deep corals globally is industrial bottom-trawl fishing, which can devastate deep reefs. Trawling is indiscriminate, sweeping up unwanted animals – including corals – as “bycatch.”“ It also stirs up sediment, which clogs deep-sea organisms’ feeding and breathing structures. Other forms of fishing, including traps, bottom longlines and dredges, can also impact the seafloor.

    Offshore energy production creates other problems. Oil and gas operations can release drilling muds and stir up sediments. Anchors and cables can directly damage reefs, and oil spills can have long-term impacts on coral health. Studies have shown that exposure to oil from the 2010 Deepwater Horizon spill caused stress and tissue damage in Gulf of Mexico deep-sea corals.

    Yet another growing concern is deep sea mining for materials such as cobalt, which is used to build batteries for cell phones and electric cars. The International Seabed Authority, a United Nations agency, is working with scientists and non-government organizations to develop a global regulatory code for deep sea mining, which is expected to be completed in 2020 or 2021. However, the International Union for the Conservation of Nature has warned that not enough is known about deep sea life to ensure that the code will protect it effectively.

    Finally, deep-sea corals are not immune to climate change. Ocean currents circulate around the planet, transporting warm surface waters into the deep sea. Warming temperatures could drive corals deeper, but deep waters are naturally higher in carbon dioxide than surface waters. As their waters become more acidified, deep-sea corals will be restricted to an increasingly narrow band of optimal conditions.

    Conservation and management

    Vast areas of deep coral habitats are on the high seas and are extremely difficult to manage. However, many countries have taken measures to protect deep corals within their territorial waters. For example, the United States has created several deep coral protected areas. And the U.S. Bureau of Ocean Energy Management restricts industry activities near deep corals and funds deep sea coral research.

    These are useful steps, but nations can only protect what they know about. Without exploration, no one would have known about the coral zone that we found off South Carolina, along one of the busiest coastlines in the United States. As a scientist, I believe it is imperative to explore and understand our deep ocean resources so we can preserve them into the future.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 4:04 pm on December 5, 2018 Permalink | Reply
    Tags: , , , , Negative mass particles, The Conversation   

    From The Conversation: “Bizarre ‘dark fluid’ with negative mass could dominate the universe – what my research suggests” 

    Conversation
    From The Conversation

    1
    Bubbles can be modelled as having a negative mass. Mike Lewinski/Flickr, CC BY-ND

    12.5.18
    Jamie Farnes

    It’s embarrassing, but astrophysicists are the first to admit it. Our best theoretical model can only explain 5% of the universe. The remaining 95% is famously made up almost entirely of invisible, unknown material dubbed dark energy and dark matter. So even though there are a billion trillion stars in the observable universe, they are actually extremely rare.

    The two mysterious dark substances can only be inferred from gravitational effects. Dark matter may be an invisible material, but it exerts a gravitational force on surrounding matter that we can measure. Dark energy is a repulsive force that makes the universe expand at an accelerating rate. The two have always been treated as separate phenomena. But my new study, published in Astronomy and Astrophysics, suggests they may both be part of the same strange concept – a single, unified “dark fluid” of negative masses.

    Negative masses are not a new idea in cosmology. Just like normal matter, negative mass particles would become more spread out as the universe expands – meaning that their repulsive force would become weaker over time. However, studies have shown that the force driving the accelerating expansion of the universe is relentlessly constant. This inconsistency has previously led researchers to abandon this idea. If a dark fluid exists, it should not thin out over time.

    In the new study, I propose a modification to Einstein’s theory of general relativity to allow negative masses to not only exist, but to be created continuously. “Matter creation” was already included in an early alternative theory to the Big Bang, known as the Steady State model. The main assumption was that (positive mass) matter was continuously created to replenish material as the universe expands. We now know from observational evidence that this is incorrect. However, that doesn’t mean that negative mass matter can’t be continuously created. I show that this assumed dark fluid is never spread too thinly. Instead it behaves exactly like dark energy.

    It’s embarrassing, but astrophysicists are the first to admit it. Our best theoretical model can only explain 5% of the universe. The remaining 95% is famously made up almost entirely of invisible, unknown material dubbed dark energy and dark matter. So even though there are a billion trillion stars in the observable universe, they are actually extremely rare.

    The two mysterious dark substances can only be inferred from gravitational effects. Dark matter may be an invisible material, but it exerts a gravitational force on surrounding matter that we can measure. Dark energy is a repulsive force that makes the universe expand at an accelerating rate. The two have always been treated as separate phenomena. But my new study, published in Astronomy and Astrophysics, suggests they may both be part of the same strange concept – a single, unified “dark fluid” of negative masses.

    Negative masses are a hypothetical form of matter that would have a type of negative gravity – repelling all other material around them. Unlike familiar positive mass matter, if a negative mass was pushed, it would accelerate towards you rather than away from you.

    Negative masses are not a new idea in cosmology. Just like normal matter, negative mass particles would become more spread out as the universe expands – meaning that their repulsive force would become weaker over time. However, studies have shown that the force driving the accelerating expansion of the universe is relentlessly constant. This inconsistency has previously led researchers to abandon this idea. If a dark fluid exists, it should not thin out over time.

    In the new study, I propose a modification to Einstein’s theory of general relativity to allow negative masses to not only exist, but to be created continuously. “Matter creation” was already included in an early alternative theory to the Big Bang, known as the Steady State model. The main assumption was that (positive mass) matter was continuously created to replenish material as the universe expands. We now know from observational evidence that this is incorrect. However, that doesn’t mean that negative mass matter can’t be continuously created. I show that this assumed dark fluid is never spread too thinly. Instead it behaves exactly like dark energy.

    I also developed a 3D computer model of this hypothetical universe to see if it could also explain the physical nature of dark matter. Dark matter was introduced to explain the fact that galaxies are spinning much faster than our models predict. This implies that some additional invisible matter must be present to prevent them from spinning themselves apart.

    My model shows that the surrounding repulsive force from dark fluid can also hold a galaxy together. The gravity from the positive mass galaxy attracts negative masses from all directions, and as the negative mass fluid comes nearer to the galaxy it in turn exerts a stronger repulsive force onto the galaxy that allows it to spin at higher speeds without flying apart. It therefore appears that a simple minus sign may solve one of the longest standing problems in physics.

    Is the universe really this weird?

    One may argue that this sounds a little far fetched. But while negative masses are bizarre, they are considerably less strange than you may immediately think. For starters, these effects may only seem peculiar and unfamiliar to us, as we reside in a region dominated by positive mass.

    Whether physically real or not, negative masses already have a theoretical role in a vast number of areas. Air bubbles in water can be modelled as having a negative mass. Recent laboratory research has also generated particles that behave exactly as they would if they had negative mass.

    And physicists are already comfortable with the concept of negative energy density. According to quantum mechanics, empty space is made up of a field of fluctuating background energy that can be negative in places – giving rise to waves and virtual particles that pop into and out of existence. This can even create a tiny force that can be measured in the lab.

    The new study could help solve many problems in modern physics. String theory, which is our best hope for unifying the physics of the quantum world with Einstein’s theory of the cosmos, is currently seen as being incompatible with observational evidence. However, string theory does suggest that the energy in empty space must be negative, which corroborates the theoretical expectations for a negative mass dark fluid.

    Moreover, the team behind the groundbreaking discovery of an accelerating universe surprisingly detected evidence for a negative mass cosmology, but took the reasonable precaution of interpreting these controversial findings as “unphysical”.

    The theory could also solve the problem of measuring the universe’s expansion. This is explained by the Hubble-Lemaître Law, the observation that more distant galaxies are moving away at a faster rate. The relationship between the speed and the distance of a galaxy is set by the “Hubble constant”, but measurements of it have continued to vary. This has led to a crisis in cosmology. Fortunately, a negative mass cosmology mathematically predicts that the Hubble “constant” should vary over time. Clearly, there is evidence that this weird and unconventional new theory deserves our scientific attention.

    Where to go from here

    The creator of the field of cosmology, Albert Einstein, did – along with other scientists including Stephen Hawking – consider negative masses. In fact, in 1918 Einstein even wrote that his theory of general relativity may have to be modified to include them.

    Despite these efforts, a negative mass cosmology could be wrong. The theory seems to provide answers to so many currently open questions that scientists will – quite rightly – be rather suspicious. However, it is often the out-of-the-box ideas that provide answers to longstanding problems. The strong accumulating evidence has now grown to the point that we must consider this unusual possibility.

    The largest telescope to ever be built – the Square Kilometre Array (SKA) – will measure the distribution of galaxies throughout the history of the universe. I’m planning to use the SKA to compare its observations to theoretical predictions for both a negative mass cosmology and the standard one – helping to ultimately prove whether negative masses exist in our reality.

    3
    The Square Kilometre Array may provide answers. SKA Project Development Office and Swinburne Astronomy Productions, CC BY-SA

    What is clear is that this new theory generates a wealth of new questions. So as with all scientific discoveries, the adventure does not end here. In fact, the quest to understand the true nature of this beautiful, unified, and – perhaps polarised – universe has only just begun.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 1:57 pm on December 3, 2018 Permalink | Reply
    Tags: , , The Conversation,   

    From The Conversation: “Scientist at work: To take atomic-scale pictures of tiny crystals, use a huge, kilometer-long synchrotron” 

    Conversation
    From The Conversation

    ANL Advanced Photon Source

    December 3, 2018
    Kerry Rippy

    It’s 4 a.m., and I’ve been up for about 20 hours straight. A loud alarm is blaring, accompanied by red strobe lights flashing. A stern voice announces, “Searching station B. Exit immediately.” It feels like an emergency, but it’s not. In fact, the alarm has already gone off 60 or 70 times today. It is a warning, letting everyone in the vicinity know I’m about to blast a high-powered X-ray beam into a small room full of electronic equipment and plumes of vaporizing liquid nitrogen.

    In the center of this room, which is called station B, I have placed a crystal no thicker than a human hair on the tip of a tiny glass fiber. I have prepared dozens of these crystals, and am attempting to analyze all of them.

    These crystals are made of organic semiconducting materials, which are used to make computer chips, LED lights, smartphone screens and solar panels. I want to find out precisely where each atom inside the crystals is located, how densely packed they are and how they interact with each other. This information will help me predict how well electricity will flow through them.

    To see these atoms and determine their structure, I need the help of a synchrotron, which is a massive scientific instrument containing a kilometer-long loop of electrons zooming around at near the speed of light. I also need a microscope, a gyroscope, liquid nitrogen, a bit of luck, a gifted colleague and a tricycle.

    Getting the crystal in place

    The first step of this experiment involves placing the super-tiny crystals on the tip of the glass fiber. I use a needle to scrape a pile of them together onto a glass slide and put them under a microscope. The crystals are beautiful – colorful and faceted like little gemstones. I often find myself transfixed, staring with sleep-deprived eyes into the microscope, and refocusing my gaze before painstakingly coaxing one onto the tip of a glass fiber.

    Once I’ve gotten the crystal attached to the fiber, I begin the often frustrating task of centering the crystal on the tip of a gyroscope inside station B. This device will spin the crystal around, slowly and continuously, allowing me to get X-ray images of it from all sides.

    1
    On the left is the gyroscope, designed to rotate the crystal through a series of different angles as the X-ray beam hits it. Behind it is the detector panel which records the diffraction spots. On the right is a zoomed in picture of a single crystal, mounted on a glass fiber attached to the tip of the gyroscope. Kerry Rippy, CC BY-ND

    As it spins, liquid nitrogen vapor is used to cool it down: Even at room temperature, atoms vibrate back and forth, making it hard to get clear images of them. Cooling the crystal to minus 196 degrees Celsius, the temperature of liquid nitrogen, makes the atoms stop moving so much.

    X-ray photography

    Once I have the crystal centered and cooled, I close off station B, and from a computer control hub outside of it, blast the sample with X-rays. The resulting image, called a diffraction pattern, is displayed as bright spots on an orange background.

    2
    This is a diffraction pattern that results when you shoot an X-ray beam at a single crystal. Kerry Rippy, CC BY-ND

    What I am doing is not very different from taking photographs with a camera and a flash. I’m about to send light rays at an object and record how the light bounces off it. But I can’t use visible light to photograph atoms – they’re too small, and the wavelengths of light in the visible part of the spectrum are too big. X-rays have shorter wavelengths, so they will diffract, or bounce off atoms.

    However, unlike with a camera, diffracted X-rays can’t be focused with a simple lens. Instead of a photograph-like image, the data I collect are an unfocused pattern of where the X-rays went after they bounced off the atoms in my crystal. A full set of data about one crystal is made up of these images taken from every angle all around the crystal as the gyroscope spins it.

    Advanced math

    My colleague, Nicholas DeWeerd, sits nearby, analyzing data sets I’ve already collected. He has managed to ignore the blaring alarms and flashing lights for hours, staring at diffraction images on his screen to, in effect, turn the X-ray images from all sides of the crystal into a picture of the atoms inside the crystal itself.

    In years past, this process might have taken years of careful calculations done by hand, but now he uses computer modeling to put all the pieces together. He is our research group’s unofficial expert at this part of the puzzle, and he loves it. “It’s like Christmas!” I hear him mutter, as he flips through twinkling images of diffraction patterns.

    3
    Solving a set of diffraction patterns produces an atomic-level picture of a crystal, showing individual molecules (left) and how they pack together to form a crystalline structure. Kerry Rippy, CC BY-ND

    I smile at the enthusiasm he’s managed to maintain so late into the night, as I fire up the synchotron to get my pictures of the crystal perched in station B. I hold my breath as diffraction patterns from the first few angles pop up on the screen. Not all crystals diffract, even if I’ve set everything up perfectly. Often that’s because each crystal is made up of lots of even smaller crystals stuck together, or crystals containing too many impurities to form a repeating crystalline pattern that we can mathematically solve.

    If this one doesn’t deliver clear images, I’ll have to start over and set up another. Luckily, in this case, the first few images that pop up show bright, clear diffraction spots. I smile and sit back to collect the rest of the data set. Now as the gyroscope whirls and the X-ray beam blasts the sample, I have a few minutes to relax.

    I would drink some coffee to stay alert, but my hands are already shaking from caffeine overload. Instead, I call over to Nick: “I’m gonna take a lap.” I walk over to a group of tricycles sitting nearby. Normally used just to get around the large building containing the synchrotron, I find them equally helpful for a desperate attempt to wake up with some exercise.

    As I ride, I think about the crystal mounted on the gyroscope. I’ve spent months synthesizing it, and soon I’ll have a picture of it. With the picture, I’ll gain understanding of whether the modifications that I have made to it, which make it slightly different than other materials I have made in the past, have improved it at all. If I see evidence of better packing or increased intermolecular interactions, that could mean the molecule is a good candidate for testing in electronic devices.

    Exhausted, but happy because I’m collecting useful data, I slowly pedal around the loop, noting that the synchrotron is in high demand. When the beamline is running, it is used 24/7, which is why I’m working through the night. I was lucky to get a time slot at all. At other stations, other researchers like me are working late into the night.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 2:08 pm on October 6, 2018 Permalink | Reply
    Tags: , , Female physics laureate No. 3, Good news at the start of the pipeline, Implicit biases about who does science, Is the number of women in STEM jobs increasing?, The Conversation, What’s not working for women, Why more women don’t win science Nobels,   

    From The Conversation: Women in STEM-“Why more women don’t win science Nobels” 

    Conversation
    From The Conversation

    October 5, 2018
    Mary K. Feeney

    1
    Only 3 percent of these prizes have gone to women since 1901. Reuters/Pawel Kopczynski

    One of the 2018 Nobel Prizes in physics went to Donna Strickland, a major accomplishment for any scientist. Yet much of the news coverage has focused on the fact that she’s only the third female physicist to receive the award, after Marie Curie in 1903 and Maria Goeppert-Mayer 60 years later.

    Though biochemical engineer Frances Arnold also won this year, for chemistry, the rarity of female Nobel laureates raises questions about women’s exclusion from education and careers in science. Female researchers have come a long way over the past century. But there’s overwhelming evidence that women remain underrepresented in the STEM fields of science, technology, engineering and math.

    Studies have shown those who persist in these careers face explicit and implicit barriers to advancement. Bias is most intense in fields that are predominantly male, where women lack a critical mass of representation and are often viewed as tokens or outsiders.

    When women achieve at the highest levels of sports, politics, medicine and science, they serve as role models for all of us, especially for girls and other women. But are things getting better in terms of equal representation? What still holds women back in the classroom, in the lab, in leadership and as award winners?

    Good news at the start of the pipeline

    Traditional stereotypes hold that women “don’t like math” and “aren’t good at science.” Both men and women report these viewpoints, but researchers have empirically disputed them. Studies show that girls and women avoid STEM education not because of cognitive inability, but because of early exposure and experience with STEM, educational policy, cultural context, stereotypes and a lack of exposure to role models.

    For the past several decades, efforts to improve the representation of women in STEM fields have focused on countering these stereotypes with educational reforms and individual programs that can increase the number of girls entering and staying in what’s been called the STEM pipeline – the path from K-12 to college to postgraduate training.

    Is the number of women in STEM jobs increasing?

    Women with college degrees remain underrepresented in science and engineering occupations in the United States, although less so than in the past. Except in computer/mathematical sciences, women have increased their proportion in each broad occupational group since the early 1990s.

    3

    These approaches are working. Women are increasingly likely to express an interest in STEM careers and pursue STEM majors in college. Women now make up half or more of workers in psychology and social sciences and are increasingly represented in the scientific workforce, though computer and mathematical sciences are an exception. According to the American Institute of Physics, women earn about 20 percent of bachelor’s degrees and 18 percent of Ph.D.s in physics, an increase from 1975 when women earned 10 percent of bachelor’s degrees and 5 percent of Ph.D.s in physics.

    More women are graduating with STEM Ph.D.s and earning faculty positions. But they go on to encounter glass cliffs and ceilings as they advance through their academic careers.

    What’s not working for women

    Women face a number of structural and institutional barriers in academic STEM careers.

    In addition to issues related to the gender pay gap, the structure of academic science often makes it difficult for women to get ahead in the workplace and to balance work and life commitments. Bench science can require years of dedicated time in a laboratory. The strictures of the tenure-track process can make maintaining work-life balance, responding to family obligations, and having children or taking family leave difficult, if not impossible.

    Additionally, working in male-dominated workplaces can leave women feeling isolated, perceived as tokens and susceptible to harassment. Women often are excluded from networking opportunities and social events and left to feel they’re outside the culture of the lab, the academic department and the field.

    When women lack critical mass – of about 15 percent or more – they are less empowered to advocate for themselves and more likely to be perceived as a minority group and an exception. When in this minority position, women are more likely to be pressured to take on extra service as tokens on committees or mentors to female graduate students.

    With fewer female colleagues, women are less likely to build relationships with female collaborators and support and advice networks. This isolation can be exacerbated when women are unable to participate in work events or attend conferences because of family or child care responsibilities and an inability to use research funds to reimburse child care.

    Universities, professional associations, and federal funders have worked to address a variety of these structural barriers. Efforts include creating family-friendly policies, increasing transparency in salary reporting, enforcing Title IX protections, providing mentoring and support programs for women scientists, protecting research time for women scientists, and targeting women for hiring, research support and advancement. These programs have mixed results. For example, research indicates that family-friendly policies such as leave and onsite child care can exacerbate gender inequity, resulting in increased research productivity for men and increased teaching and service obligations for women.

    Implicit biases about who does science

    All of us – the general public, the media, university employees, students and professors – have ideas of what a scientist and a Nobel Prize winner looks like. That image is predominantly male, white and older – which makes sense given 97 percent of the science Nobel Prize winners have been men.

    This is an example of an implicit bias: one of the unconscious, involuntary, natural, unavoidable assumptions that all of us, men and women, form about the world around us. People make decisions based on subconscious assumptions, preferences and stereotypes – sometimes even when they are counter to their explicitly held beliefs.

    Research shows that an implicit bias against women as experts and academic scientists is pervasive. It manifests itself by valuing, acknowledging and rewarding men’s scholarship over women’s scholarship. Implicit bias can work against women’s hiring, advancement and recognition of their work. For instance, women seeking academic jobs are more likely to be viewed and judged based on personal information and physical appearance. Letters of recommendation for women are more likely to raise doubts and use language that results in negative career outcomes.

    Implicit bias can affect women’s ability to publish research findings and gain recognition for that work. Men cite their own papers 56 percent more than women do. Known as the “Matilda Effect,” there is a gender gap in recognition, award winning and citations. Women’s research is less likely to be cited by others and their ideas are more likely to be attributed to men. Women’s solo-authored research takes twice as long to move through the review process. Women are underrepresented in journal editorships, as senior scholars and lead authors, and as peer reviewers. This marginalization in research gatekeeping positions works against the promotion of women’s research.

    When a woman becomes a world-class scientist, implicit bias works against the likelihood that she will be invited as a keynote or guest speaker to share her research findings, thus lowering her visibility in the field and the likelihood that she will be nominated for awards. This gender imbalance is notable in how infrequently women experts are quoted in news stories on most topics.

    Women scientists are afforded less of the respect and recognition that should come with their accomplishments. Research shows that when people talk about male scientists and experts, they’re more likely to use their surnames and more likely to refer to women by their first names. Why does this matter? Because experiments show that individuals referred to by their surnames are more likely to be viewed as famous and eminent. In fact, one study found that calling scientists by their last names led people to consider them 14 percent more deserving of a National Science Foundation career award.

    4
    Donna Strickland outside her lab at the University of Waterloo. Reuters/Peter Power

    Female physics laureate No. 3

    Strickland winning a Nobel Prize as an associate professor in physics is a major accomplishment; doing so as a woman who has almost certainly faced more barriers than her male counterparts is, in my view, monumental.

    When asked what it felt like to be the third female Nobel laureate in physics, Strickland noted that at first it was surprising to realize so few women had won the award: “But, I mean, I do live in a world of mostly men, so seeing mostly men doesn’t really ever surprise me either.”

    Seeing mostly men has been the history of science. Addressing structural and implicit bias in STEM will hopefully prevent another half-century wait before the next woman is acknowledged with a Nobel Prize for her contribution to physics. I look forward to the day when a woman receiving the most prestigious award in science is newsworthy only for her science and not her gender.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 11:59 am on September 8, 2018 Permalink | Reply
    Tags: , , , , , , Ten years of Large Hadron Collider discoveries are just the start of decoding the universe, The Conversation   

    From The Conversation: “Ten years of Large Hadron Collider discoveries are just the start of decoding the universe” 

    Conversation
    From The Conversation


    The activity during a high-energy collision at the CMS control room of the European Organization for Nuclear Research, CERN, at their headquarters outside Geneva, Switzerland. AP Photo

    “Ten years! Ten years since the start of operations for the Large Hadron Collider (LHC), one of the most complex machines ever created. The LHC is the world’s largest particle accelerator, buried 100 meters under the French and Swiss countryside with a 17-mile circumference.

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    On Sept. 10, 2008, protons, the center of a hydrogen atom, were circulated around the LHC accelerator for the first time. However, the excitement was short-lived because on Sept. 22 an incident occurred that damaged more than 50 of the LHC’s more than 6,000 magnets – which are critical for keeping the protons traveling on their circular path. Repairs took more than a year, but in March 2010 the LHC began colliding protons. The LHC is the crown jewel of CERN, the European particle physics laboratory that was founded after World War II as a way to reunite and rebuild science in war-torn Europe. Now scientists from six continents and 100 countries conduct experiments there.

    You might be wondering what the LHC does and why it is a big deal. Great questions. The LHC collides two beams of protons together at the highest energies ever achieved in a laboratory. Six experiments located around the 17-mile ring study the results of these collisions with massive detectors built in underground caverns. That’s the what, but why? The goal is to understand the nature of the most basic building blocks of universe and how they interact with each other. This is fundamental science at its most basic.

    3
    View of the LHC in its tunnel at CERN (European particle physics laboratory) near Geneva, Switzerland. The LHC is a 27-kilometer-long underground ring of superconducting magnets housed in this pipe-like structure, or cryostat. The cryostat is cooled by liquid helium to keep it at an operating temperature just above absolute zero. It will accelerate two counterrotating beam of protons to an energy of 7 tera-electron volts (TeV) and then bring them to collide head-on. Several detectors are being built around the LHC to detect the various particles produced by the collision. Martial Trezzini/KEYSTONE/AP Photo.

    The LHC has not disappointed. One of the discoveries made with the LHC includes the long sought-after Higgs boson, which gives mass to all of the protons and neutrons in the quark gluon plasma, predicted in 1964 by scientists working to combine theories of two of the fundamental forces of nature.

    CERN CMS Higgs Event


    CERN ATLAS Higgs Event

    I work on one of the six LHC experiments – the Compact Muon Solenoid experiment designed to discover the Higgs boson and search for signs of previously unknown particles or forces.

    CERN/CMS Detector

    My institution, Florida State University, joined the Compact Muon Solenoid collaboration in 1994 when I was a young graduate student at another school working on a different experiment at a different laboratory. Planning for the LHC dates back to 1984. The LHC was hard to build and expensive – 10 billion euros – and took 24 years to come to fruition. Now we are celebrating 10 years since the LHC began operating.

    Discoveries from the LHC

    The most significant discovery to come from the LHC so far is the discovery of the Higgs boson on July 4, 2012. The announcement was made at CERN and captivated a worldwide audience. In fact, my wife and I watched it via webcast on our big screen TV in our living room. Since the announcement was at 3 a.m. Florida time, we went for pancakes at IHOP to celebrate afterwards.

    The Higgs boson was the last remaining piece of what we call the standard model of particle physics.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.


    Standard Model of Particle Physics from Symmetry Magazine

    This theory covers all of the known fundamental particles – 17 of them – and three of the four forces through which they interact, although gravity is not yet included. The standard model is an incredibly well-tested theory. Two of the six scientists who developed the part of the standard model that predicts the Higgs boson won the Nobel Prize in 2013.

    3
    The Higgs boson, sometimes refered to as the ‘God particle,’ was first seen during by experiments at the Large Hadron Collider. Designua/Shutterstock.com

    I am often asked, why do we continue to run experiments, smashing together protons, if we’ve already discovered the Higgs boson? Aren’t we done? Well, there is still lots to be understood. There are a number of questions that the standard model does not answer. For example, studies of galaxies and other large-scale structures in the universe indicate that there is a lot more matter out there than we observe. We call this dark matter since we can’t see it. The most common explanation to date is that dark matter is made of an unknown particle. Physicists hope that the LHC may be able to produce this mystery particle and study it. That would be an amazing discovery.

    Just last week, the ATLAS and Compact Muon Solenoid collaborations announced the first observation of the Higgs boson decaying, or breaking apart, into bottom quarks. The Higgs boson decays in many different ways – some rare, some common. The standard model makes predictions about how often each type of decay happens. To fully test the model, we need to observe all of the predicted decays. Our recent observation is in agreement with the standard model – another success.

    More questions, more answers to come

    There are lots of other puzzles in the universe and we may require new theories of physics to explain such phenomena – such as matter/anti-matter asymmetry to explain why the universe has more matter than anti-matter, or the hierarchy problem to understand why gravity is so much weaker than the other forces.

    But for me, the quest for new, unexplained data is important because every time that physicists think we have it all figured out, nature provides a surprise that leads to a deeper understanding of our world.

    The LHC continues to test the standard model of particle physics. Scientists love when theory matches data. But we usually learn more when they don’t. This means we don’t fully understand what is happening. And that, for many of us, is the future goal of the LHC: to discover evidence of something we don’t understand. There are thousands of theories that predict new physics that we have not observed. Which are right? We need a discovery to learn if any are correct.

    CERN plans to continue LHC operations for a long time. We are planning upgrades to the accelerator and detectors to allow it to run through 2035.

    It is not clear who will retire first, me or the LHC. Ten years ago, we anxiously awaited the first beams of protons. Now we are busy studying a wealth of data and hope for a surprise that leads us down a new path. Here’s to looking forward to the next 20 years.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 6:19 am on August 24, 2018 Permalink | Reply
    Tags: , , , , , , The Conversation   

    From The Conversation: “We’re going to get a better detector: time for upgrades in the search for gravitational waves” 

    Conversation
    From The Conversation

    August 16, 2018
    Robert Ward

    It’s been a year since ripples in space-time from a colliding pair of dead stars tickled the gravitational wave detectors of the Advanced LIGO and Advanced Virgo facilities.


    Soon after, astronomers around the world began a campaign to observe the afterglow of the collision of a binary neutron star merger in radio waves, microwaves, visible light, x-rays and more.

    See https://sciencesprings.wordpress.com/2017/10/16/from-ucsc-a-uc-santa-cruz-special-report-neutron-stars-gravitational-waves-and-all-the-gold-in-the-universe/

    This was the dawn of multi-messenger astronomy: a new era in astronomy, where events in the universe are observed with more than just a single type of radiation. In this case, the messengers were gravitational waves and electromagnetic radiation.

    What we’ve learned (so far)

    From this single event, we learned an incredible amount. Last October, on the day the detection was made public, 84 scientific papers were published (or the preprints made available).

    We learned that gravity and light travel at the same speed, neutron star mergers are a source of short gamma-ray bursts, and that kilonovae – the explosion from a neutron star merger – are where our gold comes from.

    This rich science came from the fact that we were able to combine our observatories to witness this single event from multiple astronomical “windows”. The gravitational waves arrived first, followed 1.7 seconds later by gamma-rays. That is a pretty small delay, considering the waves had been travelling for 130 million years.

    Over the next few weeks, visible light and radio waves began to be observed and then slowly faded.

    It seemed like the news about gravitational waves was coming fast and furious, with the first detection announced in 2016, a Nobel prize in 2017, and the announcement of the binary neutron star merger just weeks after the Nobel prize.

    Time for upgrades

    On this first anniversary of the neutron star merger, the gravitational wave detectors are offline for upgrades. They actually went offline shortly after the detection and will come back online some time early in 2019.

    The work of making gravitational wave detectors function requires extraordinary patience and dedication. These are exquisite experiments – it took more than 40 years of technological development by a community of more than a thousand scientists to get to the point of detecting the first signal.

    Naturally, improving on this work is not easy. So what does it actually take?

    We really do listen to gravitational waves, and our detectors act more like microphones than telescopes or cameras.

    Quiet please!

    To detect gravitational waves, we need to do more than just turn off the dishwasher. We need to build the quietest, best-isolated thing on Earth.

    Unfortunately, the laws of quantum mechanics and thermodynamics both prevent us from eliminating the noise entirely. Nonetheless, we strive to do the best that these fundamental limits permit. This involves, among many other extraordinary things, hanging our mirrors on glass threads .

    2
    Before sealing up the chamber and pumping the vacuum system down, a LIGO optics technician inspects one of LIGO’s core optics (mirrors) by illuminating its surface with light at a glancing angle. Matt Heintze/Caltech/MIT/LIGO Lab

    Our mirrors weight 40kg each and are suspended from four of these glass threads, which are less than a half-millimetre in diameter and exquisitely crafted.

    The threads are under enormous stress, and the slightest imperfection (or the slightest touch) can cause them to explode.

    Just such an explosion happened earlier this year while installing a new mirror. Fortunately, the precious mirror fell into a cradle designed for just such a possibility, and was not damaged.

    Nonetheless, the delicate, intricate work of creating the glass threads, attaching them to the mirror, hanging the mirror and then installing it all needed to be redone.

    Improvements to the detector

    This was a heartbreaking setback for the team, but the added delay was not entirely in vain. In parallel with remaking the glass threads and rehanging the new mirror, we made some other improvements to the detector, for which we otherwise would not have had enough time.

    One of the goals of this upgrade period is to install something called a quantum squeezed light source into the gravitational wave detectors.

    As mentioned earlier, quantum mechanics mandates a certain minimum amount of noise in any measurement. We can’t arbitrarily reduce this quantum noise, but we can move it around and change its shape by squeezing it.

    This is a bit like sweeping dust under the rug. It’s not really gone, but it might not bother you so much anymore. The quantum squeezed light source does just this.

    3
    Australian National University scientists Nutsinee Kijbunchoo and Terry McCrae build components for a quantum squeezed light source at LIGO Hanford Observatory in Washington, US. Nutsinee Kijbunchoo

    A gravitational wave detector is already a very complex system, and a squeezed light source is another complex system, so putting them together can be a challenge.

    Despite the complexity of this challenge, when the squeezed light source was activated for the first time at the LIGO detector in Livingston, Louisiana, US, in February this year there was an immediate improvement in the quantum noise: the gravitational wave detector output got just a bit quieter.

    ESA/NASA eLISA space based, the future of gravitational wave research

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
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