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  • richardmitnick 3:40 pm on May 5, 2022 Permalink | Reply
    Tags: "In Antarctica scientists discover a vast salty groundwater system under the ice sheet – with implications for sea level rise", A new discovery deep beneath one of Antarctica’s rivers of ice could change scientists’ understanding of how the ice flows with important implications for estimating future sea level rise., , , , , The Conversation (AU)   

    From The Conversation (AU): “In Antarctica scientists discover a vast salty groundwater system under the ice sheet – with implications for sea level rise” 

    From The Conversation (AU)

    May 5, 2022

    Matthew Siegfried
    Assistant Professor of Geophysics and Hydrologic Science and Engineering
    Colorado School of Mines

    Chloe Gustafson
    Postdoctoral Research Scientist in Geophysics
    Scripps Institution of Oceanography
    University of California-San Diego

    A new discovery deep beneath one of Antarctica’s rivers of ice could change scientists’ understanding of how the ice flows, with important implications for estimating future sea level rise.

    1
    Co-author Chloe Gustafson and mountaineer Meghan Seifert install measuring equipment on an ice stream. Credit: Kerry Key/The Columbia University Lamont-Doherty Earth Observatory.

    Glacier scientists Matthew Siegfried from Colorado School of Mines, Chloe Gustafson from Scripps Institution of Oceanography and their colleagues spent 61 days living in tents on an Antarctic ice stream to collect data about the land under half a mile of ice beneath their feet. They explain what the team discovered and what it says about the behavior of ice sheets in a warming world.

    What was the big takeaway from your research?

    First, it helps to understand that West Antarctic was an ocean before it was an ice sheet. If it disappeared today, it would be an ocean again with a bunch of islands. So, we know that the bedrock below the ice sheet is covered with a thick layer of sediments – the particles that accumulate onto ocean floors.

    What we didn’t know was what was in the tiny pore spaces among those sediments below the ice.

    We expected to find meltwater coming from the ice stream above, a fast-moving channel of ice that flows from the center of the ice sheet toward the ocean. What we didn’t expect, but we found in this thick layer of sediments, was a huge amount of groundwater – including saltwater from the ocean.

    Our findings [Science] suggest that this salty groundwater is the largest reservoir of liquid water below the ice stream we studied, and likely others, and it may be affecting how the ice flows on Antarctica.


    Antarctic Ice Flow Charted From Space.
    How Antarctica’s ice flows through ice streams and ice shelves to the ocean. Credit: The National Aeronautics and Space Agency.

    Liquid water is incredibly important to how fast an ice stream moves. If there’s liquid water at the base of an ice stream, it flows fast. If that water freezes or the base dries out, the ice screeches to a stop.

    Models of ice streams typically consider only [Paleoceanography and Paleoclimatology] whether ice at the base has reached the melting point or if water has flowed from upstream along the base of the ice. Scientists had never considered that more water was available under the ice sheet, let alone water that is much saltier, which keeps water from freezing at lower temperatures. (Think about why communities put salt on roads in winter.)

    Our observations suggest there is so much water there, if you took the 500 to 1,900 meters (1,600 to 6,200 feet) or so of sediments below the ice stream and squeezed them like a sponge, you’d have a column of water about 220 to 820 meters (700 to 2,700 feet) deep.

    2
    Illustrations of the Whillans ice stream show liquid water under the ice from subglacial lakes (left) and groundwater within the sediment. The ice stream moves at about 300 meters per year. Modified from Gustafson et al., 2022

    This water can move through the pores in the subglacial groundwater system, just like groundwater elsewhere, but in Antarctica, there is a dynamic ice sheet on top. When the ice sheet gets thicker, it exerts more pressure on the sediment below, so it could drive meltwater from the base of the ice sheet [Wiley] deeper into the sediment. When the ice gets thinner, however, it could draw water, now a little saltier, out of the sediments. That saltier water could affect how fast the ice flows.

    Knowing that there is a massive reservoir of water that may be linked to how fast-flowing regions of Antarctica behave means scientists need to rethink our understanding of ice streams.

    What does finding liquid water in the sediments tell scientists about Antarctica?

    The salty groundwater was a clear sign of how far inland the boundary between the ice sheet and the ocean once reached.

    This boundary, known as the grounding line, is incredibly important. When ice flows across the grounding line, it starts to float in the ocean. If you know how the grounding line is shifting, you have a good sense of how much ice is being contributed to the global ocean.

    The fact that there were marine waters beneath our feet meant that the grounding line was upstream of us at some point, at least 70 miles (110 kilometers) from where it is today.

    4
    The team’s survey points on the Whillan’s ice stream in 2018-2019 and the grounding line. Kerry Key/Lamont-Doherty Earth Observatory.

    Whillans ice stream is pretty remote. How did you determine what was happening a mile below you?

    Our site is about a two-hour flight from McMurdo Station, Antarctica. The plane lands on skis and drops off everything you need to live. Then it takes off, and it’s you, your field team, and a couple pallets of cargo.

    In all, we slept 61 days in a tent that season. Each day, we packed our snowmobiles, put in the coordinates for a site, and installed magnetotelluric stations.

    Each station has three magnetometers – pointing east-west, north-south and vertical – and two pairs of electrodes – aligned east-west and north-south. These instruments can detect the electromagnetic signatures of different Earth materials in the subsurface.


    Installing a magnetotelluric station on the Whillans ice stream.
    Time-lapse of installing a magnetotelluric station at Subglacial Lake Whillan in West Antarctica.

    Natural variations in the Earth’s magnetic and electric fields are created by events across the globe, such as solar wind interacting with the Earth’s ionosphere and lightning strikes. A change in the Earth’s magnetic and electric fields induces secondary electromagnetic fields in the subsurface, and the strength of those fields is related to how well the material there conducts electricity.

    So, by measuring electric and magnetic fields on the ice surface, we can figure out the conductivity of the subsurface materials, including water. It’s the same method the oil and gas industry used to find fossil fuels.

    We could see the groundwater, and since salt water has far greater conductivity than fresh water, we could estimate how salty it was.

    What else might be in the groundwater?

    Any time we’ve poked a hole through Antarctica, it’s been teeming with microbial life. There’s no reason to think microbes aren’t gnawing away at nutrients in the groundwater, too.

    When you have microbial ecosystems that are cut off for extended periods of time – in this case, seawater was likely deposited there 5,000-10,000 years ago – you start to have a pretty good analog for how life might exist on other planetary bodies, locked in the subsurface and buried underneath thick ice.

    Where there’s life, there is also the question of carbon.

    We know that there are microbes in subglacial lakes and rivers at the top of the sediment that are consuming carbon and transforming it into greenhouse gases like methane and carbon dioxide. We know all of this carbon ultimately gets transferred to the Southern Ocean. But we still don’t have great measurements of any of this.

    This is a new environment, and there’s a lot of research still to do. We have observations from one ice stream. It’s like sticking a straw in the groundwater system in Florida and saying, “Yeah, there’s something here” – but what does the rest of the continent look like?

    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 (AU) 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 4:30 pm on April 29, 2022 Permalink | Reply
    Tags: "Blasting out Earth’s location with the hope of reaching aliens is a controversial idea. Two teams of scientists are doing it anyway", The Conversation (AU)   

    From The Conversation (AU): “Blasting out Earth’s location with the hope of reaching aliens is a controversial idea. Two teams of scientists are doing it anyway” 

    From The Conversation (AU)

    April 29, 2022
    Chris Impey
    University Distinguished Professor of Astronomy
    University of Arizona

    Chris Impey receives funding from the National Science Foundation.

    “If a person is lost in the wilderness, they have two options. They can search for civilization, or they could make themselves easy to spot by building a fire or writing HELP in big letters. For scientists interested in the question of whether intelligent aliens exist, the options are much the same.

    For over 70 years, astronomers have been scanning for radio or optical signals from other civilizations in the search for extraterrestrial intelligence, called SETI. Most scientists are confident that life exists on many of the 300 million potentially habitable worlds in the Milky Way galaxy. Astronomers also think there is a decent chance some life forms have developed intelligence and technology. But no signals from another civilization have ever been detected, a mystery that is called “The Great Silence.”

    While SETI has long been a part of mainstream science, METI, or messaging extraterrestrial intelligence, has been less common.

    I’m a professor of astronomy who has written extensively about the search for life in the universe. I also serve on the advisory council for a nonprofit research organization that’s designing messages to send to extraterrestrial civilizations.

    METI (Messaging Extraterrestrial Intelligence)

    In the coming months, two teams of astronomers are going to send messages into space in an attempt to communicate with any intelligent aliens who may be out there listening.

    These efforts are like building a big bonfire in the woods and hoping someone finds you. But some people question whether it is wise to do this at all.

    The history of METI

    Early attempts to contact life off Earth were quixotic messages in a bottle.

    In 1972, NASA launched the Pioneer 10 spacecraft toward Jupiter carrying a plaque with a line drawing of a man and a woman and symbols to show where the craft originated.

    3
    The Pioneer 10 spacecraft carries this plaque, which describes some basic information about humans and the Earth. Carl Sagan, Frank Drake, Linda Salzman Sagan, NASA Ames Research Center via WikimediaCommons

    In 1977, NASA followed this up with the famous Golden Record attached to the Voyager 1 spacecraft.

    These spacecraft – as well as their twins, Pioneer 11 and Voyager 2 – have now all left the solar system. But in the immensity of space, the odds that these or any other physical objects will be found are fantastically minuscule.

    Electromagnetic radiation is a much more effective beacon.

    Astronomers beamed the first radio message designed for alien ears from the Arecibo Observatory in Puerto Rico in 1974.

    The series of 1s and 0s was designed to convey simple information about humanity and biology and was sent toward the globular cluster M13. Since M13 is 25,000 light-years away, you shouldn’t hold your breath for a reply.

    In addition to these purposeful attempts at sending a message to aliens, wayward signals from television and radio broadcasts have been leaking into space for nearly a century. This ever-expanding bubble of earthly babble has already reached millions of stars. But there is a big difference between a focused blast of radio waves from a giant telescope and diffuse leakage – the weak signal from a show like I Love Lucy fades below the hum of radiation left over from the Big Bang soon after it leaves the solar system.

    4
    The new FAST telescope in China is the largest radio telescope ever built and will be used to send a message toward the center of the galaxy. Ou Dongqu/Xinhua via Getty Images.

    Sending new messages

    Nearly half a century after the Arecibo message, two international teams of astronomers are planning new attempts at alien communication. One is using a giant new radio telescope, and the other is choosing a compelling new target.

    One of these new messages will be sent from the world’s largest radio telescope, in China, sometime in 2023. The telescope, with a 1,640-foot (500-meter) diameter, will beam a series of radio pulses over a broad swath of sky. These on-off pulses are like the 1s and 0s of digital information.

    The message is called The Beacon in the Galaxy and includes prime numbers and mathematical operators, the biochemistry of life, human forms, the Earth’s location and a time stamp. The team is sending the message toward a group of millions of stars near the center of the Milky Way galaxy, about 10,000 to 20,000 light-years from Earth. While this maximizes the pool of potential aliens, it means it will be tens of thousands of years before Earth may get a reply.

    The other attempt is targeting only a single star, but with the potential for a much quicker reply. On Oct. 4, 2022, a team from the Goonhilly Satellite Earth Station in England will beam a message toward the star TRAPPIST-1. This star has seven planets, three of which are Earth-like worlds in the so-called “Goldilocks zone” – meaning they could be home to liquid and potentially life, too.

    TRAPPIST-1 is just 39 light-years away, so it could take as few as 78 years for intelligent life to receive the message and Earth to get the reply.

    Ethical questions

    The prospect of alien contact is ripe with ethical questions, and METI is no exception.

    METI (Messaging Extraterrestrial Intelligence) International has announced plans to start sending signals into space.

    The first is: Who speaks for Earth? In the absence of any international consultation with the public, decisions about what message to send and where to send it are in the hands of a small group of interested scientists.

    But there is also a much deeper question. If you are lost in the woods, getting found is obviously a good thing. When it comes to whether humanity should be broadcasting a message to aliens, the answer is much less clear-cut.

    Before he died, iconic physicist Stephen Hawking was outspoken about the danger of contacting aliens with superior technology. He argued that they could be malign and if given Earth’s location, might destroy humanity. Others see no extra risk, since a truly advanced civilization would already know of our existence. And there is interest. Russian-Israeli billionaire Yuri Milner has offered $1 million for the best design of a new message and an effective way to transmit it.

    To date, no international regulations govern METI, so the experiments will continue, despite concerns.

    For now, intelligent aliens remain in the realm of science fiction. Books like The Three-Body Problem by Cixin Liu offer somber and thought-provoking perspectives on what the success of METI efforts might look like. It doesn’t end well for humanity in the books. If humans ever do make contact in real life, I hope the aliens come in peace.”

    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 (AU) 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 2:09 pm on March 31, 2022 Permalink | Reply
    Tags: "Volcanoes diamonds and blobs- a billion-year history of Earth’s interior shows it’s more mobile than we thought", Deep in the Earth beneath us lie two blobs the size of continents. One is under Africa, Research shows Earth’s blobs have changed shape and location far more than previously thought., Scientists generally agree the blobs are linked to the movement of tectonic plates at Earth’s surface., The blobs are in the mantle the thick layer of hot rock between Earth’s crust and its core., The blobs are thought to be the birthplace of rising columns of hot rock called “deep mantle plumes” that reach Earth’s surface., The blobs have their roots 2900km below the surface almost halfway to the centre of the Earth., The Conversation (AU), the other under the Pacific Ocean.   

    From The Conversation (AU): “Volcanoes diamonds and blobs- a billion-year history of Earth’s interior shows it’s more mobile than we thought” 

    From The Conversation (AU)

    Nicolas Flament
    Senior Lecturer, University of Wollongong (AU)

    Andrew Merdith
    Research fellow, University of Leeds (UK)

    Ömer F. Bodur
    Postdoctoral research fellow, University of Wollongong

    Simon Williams
    Research Fellow, Northwest University [西北大学](CN)

    1
    Earth’s interior 80 million years ago with hot structures in yellow to red (darker is shallower) and cold structures in blue (darker is deeper). Credit: Ömer Bodur/Nature

    Deep in the Earth beneath us lie two blobs the size of continents. One is under Africa, the other under the Pacific Ocean.

    The blobs have their roots 2900km below the surface almost halfway to the centre of the Earth. They are thought to be the birthplace of rising columns of hot rock called “deep mantle plumes” that reach Earth’s surface.

    When these plumes first reach the surface, giant volcanic eruptions occur – the kind that contributed to the extinction of the dinosaurs 65.5 million years ago. The blobs may also control the eruption of a kind of rock called kimberlite, which brings diamonds from depths 120-150km (and in some cases up to around 800km) to Earth’s surface.

    Scientists have known the blobs existed for a long time, but how they have behaved over Earth’s history has been an open question. In new research, we modelled a billion years of geological history and discovered the blobs gather together and break apart much like continents and supercontinents.

    2
    Earth’s blobs as imaged from seismic data. The African blob is at the top and the Pacific blob at the bottom. Credit: Ömer Bodur.

    A model for Earth blob evolution

    The blobs are in the mantle the thick layer of hot rock between Earth’s crust and its core. The mantle is solid but slowly flows over long timescales. We know the blobs are there because they slow down waves caused by earthquakes, which suggests the blobs are hotter than their surroundings.

    Scientists generally agree the blobs are linked to the movement of tectonic plates at Earth’s surface. However, how the blobs have changed over the course of Earth’s history has puzzled them.

    One school of thought has been that the present blobs have acted as anchors, locked in place for hundreds of millions of years while other rock moves around them. However, we know tectonic plates and mantle plumes move over time, and research suggests the shape of the blobs is changing.

    Our new research [Nature] shows Earth’s blobs have changed shape and location far more than previously thought. In fact, over history they have assembled and broken up in the same way that continents and supercontinents have at Earth’s surface.

    We used Australia’s National Computational Infrastructure to run advanced computer simulations of how Earth’s mantle has flowed over a billion years.

    These models are based on reconstructing the movements of tectonic plates. When plates push into one another, the ocean floor is pushed down between them in a process known as subduction. The cold rock from the ocean floor sinks deeper and deeper into the mantle, and once it reaches a depth of about 2,000km it pushes the hot blobs aside.

    We found that just like continents, the blobs can assemble – forming “superblobs” as in the current configuration – and break up over time.

    A key aspect of our models is that although the blobs change position and shape over time, they still fit the pattern of volcanic and kimberlite eruptions recorded at Earth’s surface. This pattern was previously a key argument for the blobs as unmoving “anchors”.

    Strikingly, our models reveal the African blob assembled as recently as 60 million years ago – in stark contrast to previous suggestions the blob could have existed in roughly its present form for nearly ten times as long.

    Remaining questions about the blobs

    How did the blobs originate? What exactly are they made of? We still don’t know.

    The blobs may be denser than the surrounding mantle, and as such they could consist of material separated out from the rest of the mantle early in Earth’s history. This could explain why the mineral composition of the Earth is different from that expected from models based on the composition of meteorites.

    Alternatively, the density of the blobs could be explained by the accumulation of dense oceanic material from slabs of rock pushed down by tectonic plate movement.

    Regardless of this debate, our work shows sinking slabs are more likely to transport fragments of continents to the African blob than to the Pacific blob. Interestingly, this result is consistent with recent work suggesting the source of mantle plumes rising from the African blob contains continental material, whereas plumes rising from the Pacific blob do not.

    Tracking the blobs to find minerals and diamonds

    While our work addresses fundamental questions about the evolution of our planet, it also has practical applications.

    Our models provide a framework to more accurately target the location of minerals associated with mantle upwelling. This includes diamonds brought up to the surface by kimberlites that seem to be associated with the blobs.

    Magmatic sulfide deposits, which are the world’s primary reserve of nickel, are also associated with mantle plumes. By helping target minerals such as nickel (an essential ingredient of lithium-ion batteries and other renewable energy technologies) our models can contribute to the transition to a low-emission economy.

    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 (AU) 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 11:40 am on March 25, 2022 Permalink | Reply
    Tags: "Tiny satellites are changing the way we explore our planet and beyond", , , CubeSats are a widely used format-10cm along each side-which can be built with commercial off-the-shelf electronic components., , , The Conversation (AU)   

    From The Conversation (AU): “Tiny satellites are changing the way we explore our planet and beyond” 

    From The Conversation (AU)

    3.24.22

    Shane Keating
    Senior Lecturer in Mathematics and Oceanography
    The University of New South Wales (AU) – Sydney
    1

    Clare Kenyon
    Astrophysicist and Science Communicator
    The University of Melbourne (AU)
    4

    Want to go to space? It could cost you.

    This month, the SpaceX Crew Dragon spacecraft will make the first fully-private, crewed flight to the International Space Station. The going price for a seat is US$55 million. The ticket comes with an eight-day stay on the space station, including room and board – and unrivalled views.

    Virgin Galactic and Blue Origin offer cheaper alternatives, which will fly you to the edge of space for a mere US$250,000-500,000. But the flights only last between ten and 15 minutes, barely enough time to enjoy an in-flight snack.

    But if you’re happy to keep your feet on the ground, things start to look more affordable. Over the past 20 years, advances in tiny satellite technology have brought Earth orbit within reach for small countries, private companies, university researchers, and even do-it-yourself hobbyists.

    Science in space

    We are scientists who study our planet and the universe beyond. Our research stretches to space in search of answers to fundamental questions about how our ocean is changing in a warming world, or to study the supermassive black holes beating in the hearts of distant galaxies.

    The cost of all that research can be, well, astronomical. The James Webb Space Telescope, which launched in December 2021 and will search for the earliest stars and galaxies in the universe, had a final price tag of US$10 billion after many delays and cost overruns.

    The price tag for the International Space Station, which has hosted almost 3,000 scientific experiments over 20 years, ran to US$150 billion, with another US$4 billion each year to keep the lights on.

    .

    Even weather satellites, which form the backbone of our space-based observing infrastructure and provide essential measurements for weather forecasting and natural disaster monitoring, cost up to US$400 million each to build and launch.

    Budgets like these are only available to governments and national space agencies – or a very select club of space-loving billionaires.

    Space for everyone

    More affordable options are now democratising access to space. So-called nanosatellites, with a payload of less than 10kg including fuel, can be launched individually or in “swarms”.

    Since 1998, more than 3,400 nanosatellite missions have been launched and are beaming back data used for disaster response, maritime traffic, crop monitoring, educational applications and more.

    A key innovation in the small satellite revolution is the standardisation of their shape and size, so they can be launched in large numbers on a single rocket.

    CubeSats are a widely used format-10cm along each side-which can be built with commercial off-the-shelf electronic components. They were developed in 1999 by two professors in California, Jordi Puig-Suari and Bob Twiggs, who wanted graduate students to get experience designing, building and operating their own spacecraft.

    Twiggs says the shape and size were inspired by Beanie Babies, a kind of collectable stuffed toy that came in a 10cm cubic display case.

    Commercial launch providers like SpaceX in California and Rocket Lab in New Zealand offer “rideshare” missions to split the cost of launch across dozens of small satellites. You can now build, test, launch and receive data from your own CubeSat for less than US$200,000.

    The universe in the palm of your hand

    Small satellites have opened exciting new ways to explore our planet and beyond.

    One project we are involved in uses CubeSats and machine learning techniques to monitor Antarctic sea ice from space. Sea ice is a crucial component of the climate system and improved measurements will help us better understand the impact of climate change in Antarctica.

    5
    Spire Global operates a fleet of more than 110 nanosatellites. Spire Global.

    Sponsored by the UK-Australia Space Bridge program, the project is a collaboration between universities and Antarctic research institutes in both countries and a UK-based satellite company called Spire Global. Naturally, we called the project IceCube.

    Small satellites are starting to explore beyond our planet, too. In 2018, two nanosatellites accompanied the NASA Insight mission to Mars to provide real-time communication with the lander during its decent. In May 2022, Rocket Lab will launch the first CubeSat to the Moon as a precursor to NASA’s Artemis program, which aims to land the first woman and first person of colour on the Moon by 2024.

    Tiny spacecraft have even been proposed for a voyage to another star. The Breakthough Starshot project wants to launch a fleet of 1,000 spacecraft each centimetres in size to the Alpha Centauri star system, 4.37 light-years away.

    Propelled by ground-based lasers, the spacecraft would “sail” across interstellar space for 20 or 30 years and beam back images of the Earth-like exoplanet Proxima Centauri b.

    Small but mighty

    With advances in miniaturization, satellites are getting ever smaller.

    6
    For a few hundred dollars you can build and launch a tiny working satellite. Ambasat.

    “Picosatellites”, the size of a can of soft drink, and “femtosatellites”, no bigger than a computer chip, are putting space within reach of keen amateurs. Some can be assembled and launched for as little as a few hundred dollars.

    A Finnish company is experimenting with a more sustainably built CubeSat made of wood. And new, smart satellites, carrying computer chips capable of artificial intelligence, can decide what information to beam back to Earth instead of sending everything, which dramatically reduces the cost of phoning home.

    Getting to space doesn’t have to cost the Earth after all.

    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 (AU) 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 8:57 am on March 23, 2022 Permalink | Reply
    Tags: "Record-Smashing Heatwaves Are Hitting Antarctica And The Arctic at The Same Time", , , , , The Conversation (AU)   

    From The Conversation (AU) via Science Alert(AU): “Record-Smashing Heatwaves Are Hitting Antarctica And The Arctic at The Same Time” 

    From The Conversation (AU)

    via

    ScienceAlert

    Science Alert(AU)

    23 MARCH 2022
    DANA M BERGSTROM ET AL.

    1
    Sunset reflection in Antarctic Sound, Antarctica. Credit: Enrique Aguirre Aves/Getty Images.

    Record-breaking heatwaves hit both Antarctica and the Arctic simultaneously this week, with temperatures reaching 47°C and 30°C higher than normal.

    Heatwaves are bizarre at any time in Antarctica, but particularly now at the equinox as Antarctica is about to descend into winter darkness. Likewise, up north, the Arctic is just emerging from winter.
    Climate Change; Global warming; Carbon Capture; Ecology
    Are these two heatwaves linked? We don’t know yet, and it’s most likely a coincidence. But we do know weather systems in Antarctica and the Arctic are connected to regions nearest to them, and these connections sometimes reach all the way to the tropics.

    And is climate change the cause? It might be. While it’s too soon to say for sure, we do know climate change is making polar heatwaves more common and severe, and the poles are warming faster than the global average.

    So let’s take a closer look at what’s driving the extreme anomalies for each region, and the flow-on effects for polar wildlife like penguins and polar bears.

    What happened in Antarctica?

    Antarctica’s heatwave was driven by a slow, intense high pressure system located southeast of Australia, which carried vast amounts of warm air and moisture deep into Antarctica’s interior. It was coupled with a very intense low pressure system over the east Antarctic interior.

    To make matters worse, cloud cover over the Antarctic ice plateau trapped heat radiating from the surface.

    Since it’s autumn in Antarctica, temperatures in the continent’s interior weren’t high enough to melt glaciers and the ice cap. But that’s not to say large swings in temperature didn’t occur.

    2
    (ClimateReanalyzer.org)
    Above: Air temperature anomalies across Antarctica at 2 meters above the ground for 18 March 2022.

    For example, Vostok in the middle of the ice plateau hit a provisional high of -17.7°C (15°C higher than previous record of -32.6°C). Concordia, the Italian-French research station also on the high plateau, experienced its highest ever temperature for any month, which was about 40°C above the March average.

    The story is very different on the coast as rain fell, which isn’t really common for the continent.

    The rain was driven primarily by an atmospheric river – a narrow band of moisture collected from warm oceans. Atmospheric rivers are found on the edge of low pressure systems and can move large amounts of water across vast distances, at scales greater than continents.

    Despite their rarity, atmospheric rivers make an important contribution to the continent’s ice sheets, as they dump relatively large amounts of snow. When surface temperatures rise above freezing, rain rather than snow falls over Antarctica.

    Last Monday (March 14) air temperatures at the Australian Casey Station reached a maximum of -1.9°C. Two days later, they were more like mid-summer temperatures, reaching a new March maximum of 5.6°C, which will melt ice.

    This is the second heatwave at Casey Station in two years. In February 2020, Casey hit 9.2°C, followed by a shocking high of 18.3°C on the Antarctic Peninsula.

    So what might this mean for wildlife?

    Adélie penguins, which live across the entire Antarctic coastline, have recently finished their summer breeding. But thankfully, the Adélie penguin chicks had already left for sea to start hunting for food on their own, so the heatwave did not impact them.

    The rain may have affected the local plant life, such as mosses, especially as they were in their annual phase of drying out for the winter. But we won’t know if there’s any damage to the plants until next summer when we can visit the moss beds again.

    What about the Arctic?

    A similar weather pattern occurred last week in the Arctic. An intense low pressure system began forming off the north-east coast of the United States. An atmospheric river formed at its junction with an adjacent high pressure system.

    This weather pattern funneled warm air into the Arctic circle. Svalbald, in Norway, recorded a new maximum temperature of 3.9°C.

    US researchers called the low pressure system a “bomb cyclone” because it formed so rapidly, undergoing the delightfully termed “bombogenesis”.

    3
    (ClimateReanalyzer.org)

    Above: Arctic air temperature anomalies at 2 meters above the ground for 17 March 2022.

    Winter sea ice conditions this year were already very low, and on land there was recent record-breaking rain across Greenland.

    If the warm conditions cause sea ice to break up earlier than normal, it could have dire impacts for many animals. For example, sea ice is a crucial habitat for polar bears, enabling them to hunt seals and travel long distances.

    Many people live in the Arctic, including Arctic Indigenous people, and we know losing sea ice disrupts subsistence hunting and cultural practices.

    What’s more, the bomb cyclone weather system brought chaotic weather to many populated areas of the Northern Hemisphere. In northern Norway, for instance, flowers have began blooming early due to three weeks of abnormally warm weather.

    A harbinger for the future

    Modelling suggests large-scale climate patterns are become more variable. This means this seemingly one-off heatwave may be a harbinger for the future under climate change.

    In particular, the Arctic has been warming twice as fast as the rest of the world. This is because the melting sea ice reveals more ocean beneath, and the ocean absorbs more heat as it’s darker.

    In fact, the Intergovernmental Panel on Climate Change (IPCC) projects Arctic sea ice to continue its current retreat, with ice-free summers possible by the 2050s.

    Antarctica’s future looks similarly concerning. The IPCC finds global warming between 2 and 3°C this century would see the West Antarctic Ice Sheet almost completely lost. Bringing global emissions down to net zero as fast as possible will help avoid the worst impacts of climate change.

    Dana M Bergstrom, Principal Research Scientist, The University of Wollongong (AU); Sharon Robinson, Professor, University of Wollongong, and Simon Alexander, Atmospheric scientist, The University of Tasmania(AU).

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation (AU) 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 1:14 pm on February 21, 2022 Permalink | Reply
    Tags: "Jupiter; Saturn; Uranus and Neptune-why our next visit to the giant planets will be so important (and just as difficult)", , The Conversation (AU)   

    From The Conversation: “Jupiter; Saturn; Uranus and Neptune-why our next visit to the giant planets will be so important (and just as difficult)” 

    From The Conversation

    February 21, 2022
    Chris James
    ARC DECRA Fellow,
    Centre for Hypersonics,
    School of Mechanical and Mining Engineering,
    The University of Queensland

    Yu Liu
    Honorary Fellow,
    The University of Queensland

    The giant planets – Jupiter, Saturn, Uranus and Neptune – are some of the most awe-inspiring in our Solar System, and have great importance for space research and our comprehension of the greater universe.

    Yet they remain the least explored – especially the “ice giants” Uranus and Neptune – due to their distance from Earth, and the extreme conditions spacecraft must survive to enter their atmospheres. As such, they’re also the least understood planets in the Solar System.

    Our ongoing [ARC] research [ARC] looks at how to overcome the harsh entry conditions experienced during giant planet missions. As we look forward to potential future missions, here’s what we might expect.

    1
    Jupiter is about ten times as large as Earth – with a 69,911km radius (compared to Earth’s 6,371km radius). Beinahegut.

    But first, what are giant planets?

    Unlike rocky planets, giant planets don’t have a surface to land on. Even in their lower atmospheres they remain gaseous, reaching extremely high pressures that would crush any spacecraft well before it could land on anything solid.

    There are two types of giant planets: gas giants and ice giants.

    The larger Jupiter and Saturn are gas giants. These are mainly made of hydrogen and helium, with an outer gaseous layer and a partially liquid “metallic” layer below that. They’re also believed to have a small rocky core.

    Uranus and Neptune have similar outer atmospheres and rocky cores, but their inner layer is made up of about 65% water and other so-called “ices” (although these technically remain liquid) such as methane and ammonia.

    2
    Relative size and composition of the giant planets in our solar system (with Earth also shown for comparison). JPL/Caltech (based on material from the Lunar and Planetary Institute)

    Slingshots to the edge of the Solar System

    Any giant planet mission is extremely difficult. Still, there have been some past missions sent to the gas giants.

    NASA’s 1989 Galileo mission had to slingshot around Venus and Earth to give it enough momentum to get to Jupiter, which it orbited for eight years.

    The 2011 Juno mission spent five years in transit, using a flyby around Earth to reach Jupiter (which it still orbits).

    Similarly, the Cassini-Huygens mission run by The National Aeronautics and Space Agency(US) and the The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU) took seven years to reach Saturn.

    The spacecraft spent 13 years exploring the planet and its surrounds, and launched a probe to explore Saturn’s moon, Titan.

    Flight times get even longer for the two ice giants, which are much further from the Sun. Neither has had a dedicated mission so far.

    A complex journey

    The last and only spacecraft to visit the ice giants was Voyager 2, which flew by Uranus in 1986 and Neptune in 1989.

    3
    Voyager 2, the only spacecraft ever to have visited Neptune, took a photo of the planet in 1989. NASA/JPL.

    Meanwhile, Uranus and Neptune are 20 and 30 times further away, respectively, from the Sun than Earth is. Power for these missions would have to be generated from the radioactive decay of plutonium (the power source for both the Galileo and Cassini missions).

    This radioactive decay can damage and interfere with instruments. It is therefore reserved for spacecraft which really need it, such as missions operating far away from the Sun.

    Fighting the heat

    The massive scale of giant planets means orbit speeds for incoming spacecraft are incredibly fast. And these speeds greatly heat up the spacecraft.

    The Galileo probe entered Jupiter’s atmosphere at 47.5 kilometres per second, surviving the harshest entry conditions ever experienced by an entry probe. The shock layer which formed at the front of the spacecraft during entry reached a temperature of 16,000℃ – around three times the temperature of the Sun’s surface.

    Even so, the distribution of the heat shield’s mass was found to be inefficient – showing we still have a lot to learn about entering giant planets.

    Proposed future probe missions to Uranus and Neptune would occur at slower entry speeds of 22km/s and 26km/s, respectively.

    For this, NASA have developed a tough but relatively lightweight material woven from carbon fibre, called HEEET (Heatshield for Extreme Entry Environment Technology), designed specifically for surviving giant planet and Venusian entry.

    While the material has been tested with a full-scale prototype, it has yet to fly on a mission.

    The next steps

    In 2024, NASA’s Europa Clipper mission will launch to investigate Jupiter’s moon Europa, which is believed to house an ocean of liquid water below its icy surface, where signs of life may be found.


    The Dragonfly mission, planned to launch in 2026, will similarly aim to search for signs of life on Saturn’s moon Titan.

    There are plans for a joint NASA-ESA mission to visit one of the ice giants within the upcoming launch window. But while there has been extensive preparation, it’s undecided which ice giant will be visited.

    A single mission to both planets is being considered. An entry probe is planned, too. But if the mission visits both planets, it’s undecided which planet’s atmosphere the probe would explore.

    If we want to meet the upcoming launch window, it’s expected mission concepts will need to be finalised by 2025, at the latest. In other words, crunch time is coming.

    Should a mission go forward, the two most important goals for NASA’s scientists will be to determine the interior makeup of ice giants (exactly what they are made of) and their composition (how they are formed).

    Other objectives will include studying their magnetic fields, which are very different to gas giants and all other types of planets.

    They’ll also want to study the heat released by both Uranus and Neptune, which both have average temperatures of around -200℃. All giant planets are meant to be very slowly cooling down, as they release energy gained during their formation.

    This heat release can be detected for Jupiter, Saturn and Neptune. Uranus, however, doesn’t seem to release heat – and scientists don’t know why.

    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 9:24 pm on January 4, 2022 Permalink | Reply
    Tags: "How could the Big Bang arise from nothing?", Albert Einstein's Theory of General Relativity proposes that a gravitational singularity may have existed., , , , , , In a gravitational singularity even the laws of quantum physics break down and the four fundamental forces (strong nuclear; weak nuclear; electromagnetic & gravity) could be unified as one!, Many-worlds quantum theory gives a new twist on conformal cyclic cosmology: Our Big Bang might be the rebirth of one single quantum multiverse containing infinitely different universes., , No matter how small the chance of something occurring if it has a non-zero chance then it occurs in some quantum parallel world., Other measurement results all play out in other universes in a multiverse effectively cut off from our own., , , Some people believe parallel universes may also be observable in cosmological data as imprints caused by another universe colliding with ours., The "Grand Unification Epoch", The "Plank Epoch", The Conversation (AU), , The measurement result we see is just one possibility-the one that plays out in our own universe., Three options to the deeper question of how the cycles began: no physical explanation at all; endlessly repeating cycles each a universe in its own right; one single cycle .   

    From The Conversation : “How could the Big Bang arise from nothing?” 

    From The Conversation

    January 3, 2022
    Alastair Wilson
    Professor of Philosophy, The University of Birmingham (UK)

    The evolution of the cosmos after the Big Bang. Into what is the universe expanding? Credit: Dana Berry/NASA Goddard.

    READER QUESTION: My understanding is that nothing comes from nothing. For something to exist, there must be material or a component available, and for them to be available, there must be something else available. Now my question: Where did the material come from that created the Big Bang, and what happened in the first instance to create that material? Peter, 80, Australia.

    “The last star will slowly cool and fade away. With its passing, the universe will become once more a void, without light or life or meaning.” So warned the physicist Brian Cox in the recent BBC series Universe. The fading of that last star will only be the beginning of an infinitely long, dark epoch. All matter will eventually be consumed by monstrous black holes, which in their turn will evaporate away into the dimmest glimmers of light. Space will expand ever outwards until even that dim light becomes too spread out to interact. Activity will cease.

    Or will it? Strangely enough, some cosmologists believe a previous, cold dark empty universe like the one which lies in our far future could have been the source of our very own Big Bang.

    The first matter

    But before we get to that, let’s take a look at how “material” – physical matter – first came about. If we are aiming to explain the origins of stable matter made of atoms or molecules, there was certainly none of that around at the Big Bang – nor for hundreds of thousands of years afterwards. We do in fact have a pretty detailed understanding of how the first atoms formed out of simpler particles once conditions cooled down enough for complex matter to be stable, and how these atoms were later fused into heavier elements inside stars. But that understanding doesn’t address the question of whether something came from nothing.

    So let’s think further back. The first long-lived matter particles of any kind were protons and neutrons, which together make up the atomic nucleus.

    The quark structure of the proton. 16 March 2006 Arpad Horvath.

    The quark structure of the neutron. 15 January 2018 Jacek Rybak.

    These came into existence around one ten-thousandth of a second after the Big Bang. Before that point, there was really no material in any familiar sense of the word. But physics lets us keep on tracing the timeline backwards – to physical processes which predate any stable matter.

    This takes us to the so-called “grand unified epoch”.

    The Beginning of the Modern Universe

    The “Grand Unification Epoch” took place from 10^-43 seconds to 10^-36 seconds after our universe was born. Quantum theory allows us to form a clearer picture of this Epoch compared to the mysterious The “Plank Epoch”.

    During the “Grand Unification Epoch”, the universe was still extremely hot and incomprehensibly small. However, it had cooled down enough to allow the force of gravity to separate from the other three fundamental forces. The unification of the strong nuclear, weak nuclear, and electromagnetic force that existed during this period of time is referred to as the electronuclear force. However, the splitting off of gravity from the electronuclear force wasn’t the only milestone of this epoch- this is also when the first elementary particles began to form.

    What Are Elementary Particles?
    Elementary Particles are particles which have no substructure- i.e. they are the simplest form of matter possible. Elementary particles are the building blocks of electrons, neutrons, protons and more! Currently, there are 17 elementary particles that have been confirmed- the unconfirmed “gravitron”is still in the theoretical category. There are 12 “matter” elementary particles and 5 “force carrier” particles.

    Standard Model of Particle Physics, Quantum Diaries.

    Fermions
    These are the matter elementary particles are what make up the physical part of subatomic particles and are referred to as fermions. The two categories of elementary fermions are quarks and leptons. Quarks combine to form particles known as Hadrons (more on that later), which make up the famous neutrons and protons; Leptons form electrons and other fundamental particles.

    Bosons
    The 5 force carrier particles mediate the interactions between the weak magnetic, strong magnetic, and electromagnetic forces. Bosons are the fundamental reason for the attractions/reactions we view as forces.

    The “Plank Epoch”
    The “Plank Epoch” encompasses the time period from 0 to 10^-43 seconds.
    This extremely small unit of time is aptly referred to as a “Plank Time”.
    Not much is truly known about this period of time, however some very interesting hypothesis have been made.

    Albert Einstein’s Theory of General Relativity proposes that a gravitational singularity may have existed. In a gravitational singularity, even the laws of quantum physics break down and the four fundamental forces (strong nuclear, weak nuclear, electromagnetic, & gravity) could be unified as one! This is an extremely odd concept to consider. It also ties into the so-called “Theory of Everything” which states that at high enough energy levels, even gravity will combine back into one unified force with the other three.

    During the “Plank Epoch”, our universe was only 10^-35 meters wide (VERY small) and 10^32 degrees celsius (VERY hot)!

    During the The “Grand Unification Epoch”, the universe was still extremely hot and incomprehensibly small. However, it had cooled down enough to allow the force of gravity to separate from the other three fundamental forces. The unification of the strong nuclear, weak nuclear, and electromagnetic force that existed during this period of time is referred to as the electronuclear force. However, the splitting off of gravity from the electronuclear force wasn’t the only milestone of this epoch- this is also when the first elementary particles began to form.

    By now, we are well into the realm of speculative physics, as we can’t produce enough energy in our experiments to probe the sort of processes that were going on at the time. But a plausible hypothesis is that the physical world was made up of a soup of short-lived elementary particles – including quarks, the building blocks of protons and neutrons. There was both matter and “antimatter” in roughly equal quantities: each type of matter particle, such as the quark, has an antimatter “mirror image” companion, which is near identical to itself, differing only in one aspect. However, matter and antimatter annihilate in a flash of energy when they meet, meaning these particles were constantly created and destroyed.

    But how did these particles come to exist in the first place? Quantum field theory tells us that even a vacuum, supposedly corresponding to empty spacetime, is full of physical activity in the form of energy fluctuations. These fluctuations can give rise to particles popping out, only to be disappear shortly after. This may sound like a mathematical quirk rather than real physics, but such particles have been spotted in countless experiments.

    The spacetime vacuum state is seething with particles constantly being created and destroyed, apparently “out of nothing”. But perhaps all this really tells us is that the quantum vacuum is (despite its name) a something rather than a nothing. The philosopher David Albert has memorably criticized accounts of the Big Bang which promise to get something from nothing in this way.

    4
    Simulation of quantum vacuum fluctuations in quantum chromodynamics. Credit: Ahmed Neutron/Wikimedia.

    Suppose we ask: where did spacetime itself arise from? Then we can go on turning the clock yet further back, into the truly ancient “Planck epoch” – a period so early in the universe’s history that our best theories of physics break down [above]. This era occurred only one ten-millionth of a trillionth of a trillionth of a trillionth of a second after the Big Bang. At this point, space and time themselves became subject to quantum fluctuations. Physicists ordinarily work separately with Quantum Mechanics, which rules the microworld of particles, and with general relativity, which applies on large, cosmic scales. But to truly understand the Planck epoch, we need a complete theory of quantum gravity, merging the two.

    We still don’t have a perfect theory of quantum gravity, but there are attempts – like string theory and loop quantum gravity. In these attempts, ordinary space and time are typically seen as emergent, like the waves on the surface of a deep ocean. What we experience as space and time are the product of quantum processes operating at a deeper, microscopic level – processes that don’t make much sense to us as creatures rooted in the macroscopic world.

    In the “Planck epoch”, our ordinary understanding of space and time breaks down, so we can’t any longer rely on our ordinary understanding of cause and effect either. Despite this, all candidate theories of quantum gravity describe something physical that was going on in the Planck epoch – some quantum precursor of ordinary space and time. But where did that come from?

    Even if causality no longer applies in any ordinary fashion, it might still be possible to explain one component of the “Planck epoch” universe in terms of another. Unfortunately, by now even our best physics fails completely to provide answers. Until we make further progress towards a “theory of everything”, we won’t be able to give any definitive answer. The most we can say with confidence at this stage is that physics has so far found no confirmed instances of something arising from nothing.

    Cycles from almost nothing

    To truly answer the question of how something could arise from nothing, we would need to explain the quantum state of the entire universe at the beginning of the Planck epoch. All attempts to do this remain highly speculative. Some of them appeal to supernatural forces like a “designer”. But other candidate explanations remain within the realm of physics – such as a multiverse, which contains an infinite number of parallel universes, or cyclical models of the universe, being born and reborn again.

    The 2020 Nobel Prize-winning physicist Roger Penrose has proposed one intriguing but controversial model for a cyclical universe dubbed “conformal cyclic cosmology”. Penrose was inspired by an interesting mathematical connection between a very hot, dense, small state of the universe – as it was at the Big Bang – and an extremely cold, empty, expanded state of the universe – as it will be in the far future. His radical theory to explain this correspondence is that those states become mathematically identical when taken to their limits. Paradoxical though it might seem, a total absence of matter might have managed to give rise to all the matter we see around us in our universe.


    Nobel Lecture: Roger Penrose, Nobel Prize in Physics 2020
    34 minutes

    In this view, the Big Bang arises from an almost nothing. That’s what’s left over when all the matter in a universe has been consumed into black holes, which have in turn boiled away into photons – lost in a void. The whole universe thus arises from something that – viewed from another physical perspective – is as close as one can get to nothing at all. But that nothing is still a kind of something. It is still a physical universe, however empty.

    How can the very same state be a cold, empty universe from one perspective and a hot dense universe from another? The answer lies in a complex mathematical procedure called “conformal rescaling”, a geometrical transformation which in effect alters the size of an object but leaves its shape unchanged.

    Penrose showed how the cold dense state and the hot dense state could be related by such rescaling so that they match with respect to the shapes of their spacetimes – although not to their sizes. It is, admittedly, difficult to grasp how two objects can be identical in this way when they have different sizes – but Penrose argues size as a concept ceases to make sense in such extreme physical environments.

    In conformal cyclic cosmology, the direction of explanation goes from old and cold to young and hot: the hot dense state exists because of the cold empty state. But this “because” is not the familiar one – of a cause followed in time by its effect. It is not only size that ceases to be relevant in these extreme states: time does too. The cold dense state and the hot dense state are in effect located on different timelines. The cold empty state would continue on forever from the perspective of an observer in its own temporal geometry, but the hot dense state it gives rise to effectively inhabits a new timeline all its own.

    It may help to understand the hot dense state as produced from the cold empty state in some non-causal way. Perhaps we should say that the hot dense state emerges from, or is grounded in, or realised by the cold, empty state. These are distinctively metaphysical ideas which have been explored by philosophers of science extensively, especially in the context of quantum gravity where ordinary cause and effect seem to break down. At the limits of our knowledge, physics and philosophy become hard to disentangle.

    Experimental evidence?

    Conformal cyclic cosmology offers some detailed, albeit speculative, answers to the question of where our Big Bang came from. But even if Penrose’s vision is vindicated by the future progress of cosmology, we might think that we still wouldn’t have answered a deeper philosophical question – a question about where physical reality itself came from. How did the whole system of cycles come about? Then we finally end up with the pure question of why there is something rather than nothing – one of the biggest questions of metaphysics.

    But our focus here is on explanations which remain within the realm of physics. There are three broad options to the deeper question of how the cycles began. It could have no physical explanation at all. Or there could be endlessly repeating cycles each a universe in its own right, with the initial quantum state of each universe explained by some feature of the universe before. Or there could be one single cycle and one single repeating universe, with the beginning of that cycle explained by some feature of its own end. The latter two approaches avoid the need for any uncaused events – and this gives them a distinctive appeal. Nothing would be left unexplained by physics.

    5
    Ongoing cycles of distinct universes in conformal cyclic cosmology. Roger Penrose.

    Penrose envisages a sequence of endless new cycles for reasons partly linked to his own preferred interpretation of quantum theory. In quantum mechanics, a physical system exists in a superposition of many different states at the same time, and only “picks one” randomly, when we measure it. For Penrose, each cycle involves random quantum events turning out a different way – meaning each cycle will differ from those before and after it. This is actually good news for experimental physicists, because it might allow us to glimpse the old universe that gave rise to ours through faint traces, or anomalies, in the leftover radiation from the Big Bang seen by the Planck satellite.

    Penrose and his collaborators believe they may have spotted these traces already [MNRAS], attributing patterns in the Planck data [CMB] to radiation from supermassive black holes in the previous universe. However, their claimed observations have been challenged by other physicists [Journal of Cosmology and Astroparticle Physics] and the jury remains out.

    CMB per European Space Agency(EU) Planck.

    Endless new cycles are key to Penrose’s own vision. But there is a natural way to convert conformal cyclic cosmology from a multi-cycle to a one-cycle form. Then physical reality consists in a single cycling around through the Big Bang to a maximally empty state in the far future – and then around again to the very same Big Bang, giving rise to the very same universe all over again.

    This latter possibility is consistent with another interpretation of quantum mechanics, dubbed the many-worlds interpretation. The many-worlds interpretation tells us that each time we measure a system that is in superposition, this measurement doesn’t randomly select a state. Instead, the measurement result we see is just one possibility – the one that plays out in our own universe. The other measurement results all play out in other universes in a multiverse effectively cut off from our own. So no matter how small the chance of something occurring if it has a non-zero chance then it occurs in some quantum parallel world. There are people just like you out there in other worlds who have won the lottery, or have been swept up into the clouds by a freak typhoon, or have spontaneously ignited, or have done all three simultaneously.

    Some people believe such parallel universes may also be observable [MNRAS] in cosmological data as imprints caused by another universe colliding with ours.

    Many-worlds quantum theory gives a new twist on conformal cyclic cosmology, though not one that Penrose agrees with. Our Big Bang might be the rebirth of one single quantum multiverse containing infinitely many different universes all occurring together. Everything possible happens – then it happens again and again and again.

    An ancient myth

    For a philosopher of science, Penrose’s vision is fascinating. It opens up new possibilities for explaining the Big Bang, taking our explanations beyond ordinary cause and effect. It is therefore a great test case for exploring the different ways physics can explain our world. It deserves more attention from philosophers.

    For a lover of myth, Penrose’s vision is beautiful. In Penrose’s preferred multi-cycle form, it promises endless new worlds born from the ashes of their ancestors. In its one-cycle form, it is a striking modern re-invocation of the ancient idea of the ouroboros, or world-serpent. In Norse mythology, the serpent Jörmungandr is a child of Loki, a clever trickster, and the giant Angrboda. Jörmungandr consumes its own tail, and the circle created sustains the balance of the world. But the ouroboros myth has been documented all over the world – including as far back as ancient Egypt.

    6
    Ouroboros on the tomb of Tutankhamun. Credit: Djehouty/Wikimedia.

    The ouroboros of the one cyclic universe is majestic indeed. It contains within its belly our own universe, as well as every one of the weird and wonderful alternative possible universes allowed by quantum physics – and at the point where its head meets its tail, it is completely empty yet also coursing with energy at temperatures of a hundred thousand million billion trillion degrees Celsius. Even Loki, the shapeshifter, would be impressed.

    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 8:24 am on December 28, 2021 Permalink | Reply
    Tags: "Hunting galaxies far far away – here’s how anyone can explore the universe", , , , , The Conversation (AU)   

    From The Conversation (AU): “Hunting galaxies far far away – here’s how anyone can explore the universe” 

    From The Conversation (AU)

    December 26, 2021
    Sara Webb
    Postdoctoral Research Fellow
    Centre for Astrophysics and Supercomputing
    The Swinburne University of Technology(AU)

    1
    Credit: The Swinburne University of Technology(AU)

    “By far my favourite thing about my job as an astronomer is those rare moments when I get to see beautiful distant galaxies, whose light left them millions to billions of years ago. It’s a combination of pure awe and scientific curiosity that excites me about “galaxy hunting”.

    In astronomy today, much of our work is handling enormous amounts of data by writing and running programs to work with images of the sky. A downside to this is that we don’t always have that “hands-on” experience of looking at every square inch of the universe while we study it. I’m going to show you, though, how I get my fix of wonder by looking at galaxies that only a select few people will ever have seen, until now.

    In just our observable universe we estimate there are over 2 trillion galaxies!

    Galaxies at your fingertips

    Only a few decades ago astronomers had to tediously examine photographic plates after a long, cold and lonely night of observing. In the 21st century we have access to information any time, anywhere via the internet.

    Automatic telescopes and surveys now provide us with so much data we require machines to help us analyse it. In some cases human eyes will only ever look at what the computers have deemed is interesting! Massive amounts of data are hosted online, just waiting to be admired, for free.

    Go online for a universe atlas

    Aladin Lite is one of the greatest online tools available to look at our universe through the eyes of many different telescopes. Here we can scan the entire sky for hidden galaxies, and even decipher information about their stellar populations and evolution.

    Let’s start our universal tour by searching for one of the most visually stunning galaxies out there, the Cartwheel Galaxy. In the Aladin interface, you can search for both the popular name of an object (like “cartwheel galaxy”) or known co-ordinates. The location will be centred in the interface.

    2
    Online view in Aladin Lite of the Cartwheel Galaxy, a lenticular/ring galaxy 500 million light years away from Earth discovered in 1941 by iconic astronomer Fritz Zwicky.

    Fritz Zwicky.

    The first image of the Cartwheel Galaxy we see is from optical imaging by the The STScI Digitized Sky Survey (US). The colours we see represent different filters from this telescope. However, these are fairly representative of what the galaxy would look like with our own eyes.

    A general rule of thumb as an astronomer is that “colour” differences within galaxies are because of physically different environments. It’s important to note that things that look blue (shorter wavelengths) are generally hotter than things that look red (longer wavelengths).

    In this galaxy, the outer ring appears to be more blue then the centre red section. This might hint at star formation and stellar activity happening in the outer ring, but less so in the centre.

    To confirm our suspicions of star formation we can select to look at data from different surveys, in different wavelengths. When young stars are forming, vast amounts of UV radiation are emitted. By changing the survey to GALEXGR6/AIS, we are now looking at only UV wavelengths, and what a difference that makes!

    3
    Online view in Aladin Lite of the Cartwheel Galaxy in GALEX UV wavelengths.

    The whole centre section of the galaxy seems to “disappear” from our image. This suggests that section is likely home to older stars, with less active stellar nurseries.

    Aladin is home to 20 different surveys. They provide imaging of the sky from optical, UV, infrared, X and gamma rays.

    When I am wandering the universe looking for interesting galaxies here, I generally start out in optical and find ones that look interesting to me. I then use the different surveys to see how the images change when looking at specific wavelengths.

    Universal Where’s Wally

    Now you’ve had a crash course in galaxy hunting, let the game begin! You can spend hours exploring the incredible images and finding interesting-looking galaxies. I recommend looking at images from DECalS/DR3 for the highest resolution and detail when zooming further in.

    4
    Top of image is cut off. It shows DECalS/DR3. No other image available.
    The DECam Legacy Survey (DECaLS) has announced its third data release. An NOAO Survey Program led by co-PIs David Schlegel (DOE’s Lawrence Berkeley National Laboratory (US)) and Arjun Dey (The National Optical Astronomy Observatory(US)), DECaLS uses the Dark Energy Camera (DECam) on the CTIO Blanco 4m telescope to image nearly square degrees of the extragalactic sky in three bands (g, r and z).

    _____________________________________________________________________________________
    Dark Energy Survey

    Dark Energy Camera [DECam] built at DOE’s Fermi National Accelerator Laboratory(US).

    NOIRLab National Optical Astronomy Observatory(US) Cerro Tololo Inter-American Observatory(CL) Victor M Blanco 4m Telescope which houses the Dark-Energy-Camera – DECam at Cerro Tololo, Chile at an altitude of 7200 feet.

    NOIRLab(US)NSF NOIRLab NOAO (US) Cerro Tololo Inter-American Observatory(CL) approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters.

    Timeline of the Inflationary Universe WMAP.

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.
    _____________________________________________________________________________________

    Earlier data releases were made in June 2015 (DR1) and February 2016 (DR2). The current status of the survey is shown here.

    The best method is to just drag the sky atlas around. If you find something interesting, you can find out any information we have on it by selecting the target icon and clicking on the object.

    To help you on your galactic expedition here are my favourite finds of the different types of objects you might see.

    4
    Examples of spiral galaxies found using Aladin online. Spirals are the most iconic galaxy shape and include many of the brightest galaxies in the nearby universe, like the Andromeda Galaxy.

    Andromeda Galaxy Messier 31 with Messier 32 -a satellite galaxy Credit:Terry Hancock- Down Under Observatory (US).

    Spiral galaxies typically have a central rotating disc with large spiral “arms” curving out from the denser central regions. They are incredibly beautiful. Our own Milky Way is a spiral galaxy.

    Credit: R. Hurt/NASA JPL-Caltech(US) Milky Way The bar is visible in this image.

    5
    Examples of elliptical galaxies. This type of galaxy has an approximately ellipsoidal shape and a smooth, nearly featureless image.

    Elliptical galaxies are largely featureless and less “flat” then spirals, with stars occupying almost a 3D ellipse at times. These type of galaxies tend to have older stars and less active star-forming regions compared to spiral galaxies.

    6
    Examples of lenticular galaxies. These are a type of galaxy intermediate between elliptical and a spiral galaxies.

    Lenticular galaxies appear like cosmic pancakes, fairly flat and featureless in the night sky. These galaxies can be thought of as the “in between” of spiral and elliptical galaxies. The majority of star formation has stopped but lenticular galaxies can still have significant amounts of dust in them.

    There are also other amazing types of galaxies, including mergers and lenses, which are just waiting for you to find them. I’d love to see what amazing things you find over on Twitter at @sarawebbscience.”

    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 (AU) 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 10:25 am on December 26, 2021 Permalink | Reply
    Tags: "2021 A year physicists asked 'What lies beyond the Standard Model?'", , , , , , , , Neutrinos [tau;muon;electron] represent three of the 17 fundamental particles in the Standard Model., , , , The Conversation (AU)   

    From The Conversation (AU) via phys.org : “2021 A year physicists asked ‘What lies beyond the Standard Model?'” 

    From The Conversation (AU)

    via

    phys.org

    December 23, 2021
    Aaron McGowan, The Conversation

    1
    Experiments at the Large Hadron Collider in Europe, like the ATLAS calorimeter seen here, are providing more accurate measurements of fundamental particles. Credit: Maximilien Brice, CC BY-NC.

    European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN].

    “If you ask a physicist like me to explain how the world works, my lazy answer might be: ‘It follows the Standard Model.’

    Standard Model of Particle Physics, Quantum Diaries

    The Standard Model explains the fundamental physics of how the universe works. It has endured over 50 trips around the Sun despite experimental physicists constantly probing for cracks in the model’s foundations.

    With few exceptions, it has stood up to this scrutiny, passing experimental test after experimental test with flying colors. But this wildly successful model has conceptual gaps that suggest there is a bit more to be learned about how the universe works.

    I am a neutrino physicist. Neutrinos represent three of the 17 fundamental particles in the Standard Model. They zip through every person on Earth at all times of day. I study the properties of interactions between neutrinos and normal matter particles.

    In 2021, physicists around the world ran a number of experiments that probed the Standard Model. Teams measured basic parameters of the model more precisely than ever before. Others investigated the fringes of knowledge where the best experimental measurements don’t quite match the predictions made by the Standard Model. And finally, groups built more powerful technologies designed to push the model to its limits and potentially discover new particles and fields. If these efforts pan out, they could lead to a more complete theory of the universe in the future.

    Filling holes in Standard Model

    In 1897, J.J. Thomson discovered the first fundamental particle, the electron, using nothing more than glass vacuum tubes and wires. More than 100 years later, physicists are still discovering new pieces of the Standard Model.

    2
    The Standard Model of physics allows scientists to make incredibly accurate predictions about how the world works, but it doesn’t explain everything. Credit: CERN, CC BY-NC.

    The Standard Model is a predictive framework that does two things. First, it explains what the basic particles of matter are. These are things like electrons and the quarks that make up protons and neutrons. Second, it predicts how these matter particles interact with each other using “messenger particles.” These are called bosons—they include photons and the famous Higgs boson—and they communicate the basic forces of nature. The Higgs boson wasn’t discovered until 2012 after decades of work at The European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire](CH), the huge particle collider in Europe.

    European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) CMS Higgs Event May 27, 2012.

    European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) ATLAS Higgs Event June 18, 2012.

    Peter Higgs – University of Edinburgh [Oilthigh Dhùn Èideann] (SCT).

    The Standard Model is incredibly good at predicting many aspects of how the world works, but it does have some holes.

    Notably, it does not include any description of gravity. While Albert Einstein’s Theory of General Relativity describes how gravity works, physicists have not yet discovered a particle that conveys the force of gravity [Quantum Mechanics’ ‘graviton’]. A proper “Theory of Everything” would do everything the Standard Model can, but also include the messenger particles that communicate how gravity interacts with other particles.

    Another thing the Standard Model can’t do is explain why any particle has a certain mass—physicists must measure the mass of particles directly using experiments. Only after experiments give physicists these exact masses can they be used for predictions. The better the measurements, the better the predictions that can be made.

    Recently, physicists on a team at CERN measured how strongly the Higgs boson feels itself.

    4
    Twice the Higgs, twice the challenge
    ATLAS searches for pairs of Higgs bosons in the rare bbɣɣ decay channel, 29 March 2021.

    Another CERN team also measured the Higgs boson’s mass more precisely than ever before.

    4
    A new result by the CMS Collaboration narrows down the mass of the Higgs boson to a precision of 0.1%.

    And finally, there was also progress on measuring the mass of neutrinos.

    KATRIN experiment aims to measure the mass of the neutrino using a huge device called a spectrometer (interior shown)KIT Karlsruhe Institute of Technology [Karlsruher Institut für Technologie] (DE).

    Physicists know neutrinos have more than zero mass but less than the amount currently detectable. A team in Germany has continued to refine the techniques that could allow them to directly measure the mass of neutrinos.

    Hints of new forces or particles

    In April 2021, members of the Muon g-2 experiment at Fermilab announced their first measurement of the magnetic moment of the muon.

    DOE’s Fermi National Accelerator Laboratory(US) Muon g-2 studio. As muons race around a ring at the Muon g-2 studio, their spin axes twirl, reflecting the influence of unseen particles.

    The muon is one of the fundamental particles in the Standard Model, and this measurement of one of its properties is the most accurate to date. The reason this experiment was important was because the measurement didn’t perfectly match the Standard Model prediction of the magnetic moment. Basically, muons don’t behave as they should. This finding could point to undiscovered particles that interact with muons.

    But simultaneously, in April 2021, physicist Zoltan Fodor and his colleagues showed how they used a mathematical method called Lattice QCD to precisely calculate the muon’s magnetic moment. Their theoretical prediction is different from old predictions, still works within the Standard Model and, importantly, matches experimental measurements of the muon.

    The disagreement between the previously accepted predictions, this new result and the new prediction must be reconciled before physicists will know if the experimental result is truly beyond the Standard Model.

    Upgrading the tools of physics

    Physicists must swing between crafting the mind-bending ideas about reality that make up theories and advancing technologies to the point where new experiments can test those theories. 2021 was a big year for advancing the experimental tools of physics.

    First, the world’s largest particle accelerator, the Large Hadron Collider at CERN, was shut down and underwent some substantial upgrades. Physicists just restarted the facility in October, and they plan to begin the next data collection run in May 2022. The upgrades have boosted the power of the collider so that it can produce collisions at 14 TeV, up from the previous limit of 13 TeV. This means the batches of tiny protons that travel in beams around the circular accelerator together carry the same amount of energy as an 800,000-pound (360,000-kilogram) passenger train traveling at 100 mph (160 kph). At these incredible energies, physicists may discover new particles that were too heavy to see at lower energies.

    SixTRack CERN LHC particles.

    Some other technological advancements were made to help the search for dark matter. Many astrophysicists believe that dark matter particles, which don’t currently fit into the Standard Model, could answer some outstanding questions regarding the way gravity bends around stars—called gravitational lensing—as well as the speed at which stars rotate in spiral galaxies. Projects like the Cryogenic Dark Matter Search have yet to find dark matter particles, but the teams are developing larger and more sensitive detectors to be deployed in the near future.

    Gravitational Lensing Gravitational Lensing National Aeronautics Space Agency (US) and European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU).


    Super Cryogenic Dark Matter Search at DOE’s SLAC National Accelerator Laboratory (US) at Stanford University (US) at SNOLAB (Vale Inco Mine, Sudbury, Canada).

    Particularly relevant to my work with neutrinos is the development of immense new detectors like Hyper-Kamiokande and DUNE.

    Hyper-Kamiokande [(神岡宇宙素粒子研究施設](JP) a neutrino physics laboratory to be located underground in the Mozumi Mine of the Kamioka Mining and Smelting Co. near the Kamioka section of the city of Hida in Gifu Prefecture, Japan.

    DOE’s Fermi National Accelerator Laboratory(US) DUNE LBNF (US) from FNAL to Sanford Underground Research Facility, Lead, South Dakota, USA.

    DOE’s Fermi National Accelerator Laboratory(US) DUNE LBNF (US) Caverns at Sanford Underground Research Facility.

    Using these detectors, scientists will hopefully be able to answer questions about a fundamental asymmetry in how neutrinos oscillate. They will also be used to watch for proton decay, a proposed phenomenon that certain theories predict should occur.

    2021 highlighted some of the ways the Standard Model fails to explain every mystery of the universe. But new measurements and new technology are helping physicists move forward in the search for the Theory of Everything.”

    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 (AU) 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 9:16 am on May 8, 2021 Permalink | Reply
    Tags: "Massive flare seen on the closest star to the solar system- What it means for chances of alien neighbors", , , , , , The Conversation (AU)   

    From The Conversation : “Massive flare seen on the closest star to the solar system- What it means for chances of alien neighbors” 

    From The Conversation

    May 3, 2021

    R. O. Parke Loyd
    Post-Doctoral Researcher in Astrophysics
    Arizona State University

    The Sun isn’t the only star to produce stellar flares. On April 21, 2021, a team of astronomers published new research [The Astrophysical Journal Letters] describing the brightest flare ever measured from Proxima Centauri in ultraviolet light.

    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    To learn about this extraordinary event – and what it might mean for any life on the planets orbiting Earth’s closest neighboring star – The Conversation spoke with Parke Loyd, an astrophysicist at Arizona State University and co-author of the paper. Excerpts from our conversation are below and have been edited for length and clarity.

    Why were you looking at Proxima Centauri?

    Proxima Centauri is the closest star to this solar system. A couple of years ago, a team discovered that there is a planet – called Proxima b – orbiting the star. It’s just a little bit bigger than Earth, it’s probably rocky and it is in what is called the habitable zone, or the Goldilocks zone. This means that Proxima b is about the right distance from the star so that it could have liquid water on its surface.

    But this star system differs from the Sun in a pretty key way. Proxima Centauri is a small star called a red dwarf – it’s around 15% of the radius of our Sun, and it’s substantially cooler. So Proxima b, in order for it to be in that Goldilocks zone, actually is a lot closer to Proxima Centauri than Earth is to the Sun.

    You might think that a smaller star would be a tamer star, but that’s actually not the case at all – red dwarfs produce stellar flares a lot more frequently than the Sun does. So Proxima b, the closest planet in another solar system with a chance for having life, is subject to space weather that is a lot more violent than the space weather in Earth’s solar system.

    What did you find?

    In 2018, my colleague Meredith MacGregor discovered flashes of light coming from Proxima Centauri that looked very different from solar flares. She was using a telescope that detects light at millimeter wavelengths to monitor Proxima Centauri and saw a big of flash of light in this wavelength. Astronomers had never seen a stellar flare in millimeter wavelengths of light.

    My colleagues and I wanted to learn more about these unusual brightenings in the millimeter light coming from the star and see whether they were actually flares or some other phenomenon. We used nine telescopes on Earth, as well as a satellite observatory, to get the longest set of observations – about two days’ worth – of Proxima Centauri with the most wavelength coverage that had ever been obtained.

    Immediately we discovered a really strong flare. The ultraviolet light of the star increased by over 10,000 times in just a fraction of a second. If humans could see ultraviolet light, it would be like being blinded by the flash of a camera. Proxima Centauri got bright really fast. This increase lasted for only a couple of seconds, and then there was a gradual decline.

    This discovery confirmed that indeed, these weird millimeter emissions are flares.

    What does that mean for chances of life on the planet?

    Astronomers are actively exploring this question at the moment because it can kind of go in either direction. When you hear ultraviolet radiation, you’re probably thinking about the fact that people wear sunscreen to try to protect ourselves from ultraviolet radiation here on Earth. Ultraviolet radiation can damage proteins and DNA in human cells, and this results in sunburns and can cause cancer. That would potentially be true for life on another planet as well.

    On the flip side, messing with the chemistry of biological molecules can have its advantages – it could help spark life on another planet. Even though it might be a more challenging environment for life to sustain itself, it might be a better environment for life to be generated to begin with.

    But the thing that astronomers and astrobiologists are most concerned about is that every time one of these huge flares occurs, it basically erodes away a bit of the atmosphere of any planets orbiting that star – including this potentially Earth-like planet. And if you don’t have an atmosphere left on your planet, then you definitely have a pretty hostile environment to life – there would be huge amounts of radiation, massive temperature fluctuations and little or no air to breathe. It’s not that life would be impossible, but having the surface of a planet basically directly exposed to space would be an environment totally different than anything on Earth.

    Is there any atmosphere left on Proxima b?

    That’s anybody’s guess at the moment. The fact that these flares are happening doesn’t bode well for that atmosphere being intact – especially if they’re associated with explosions of plasma like what happens on the Sun. But that’s why we’re doing this work. We hope the folks who build models of planetary atmospheres can take what our team has learned about these flares and try to figure out the odds for an atmosphere being sustained on this planet.

    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.

     
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