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Widespread Report on the Global Refracting Telescope Market 2020-2028 with the Leading Players Celestron, Vixen Optics, ASTRO-PHYSICS, ORION, Barska,…

Due to the pandemic, we have included a special section on the Impact of COVID 19 on the Refracting Telescope Market which would mention How the Covid-19 is affecting the Refracting Telescope Industry, Market Trends and Potential Opportunities in the COVID-19 Landscape, Covid-19 Impact on Key Regions and Proposal for Refracting Telescope Players to Combat Covid-19 Impact.

The global Refracting Telescope Market research report offers a fundamental overview of global market. It presents the extensive outline of the global market based on different parameters like market trends, market shares, size and various specifications of the market.

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The Top Key Players of Global Refracting Telescope Market:

Celestron, Vixen Optics, ASTRO-PHYSICS, ORION, Barska, TianLang, SharpStar, Bosma, Visionking, Sky Watcher, Bushnell, TAKAHASHI, Meade, Bresser

It encompasses a massive database featuring numerous market segments and sub-segments. The study also offers importance on latest platforms along with the effect of certain platforms on market growth. It compiles in-depth informative data of the market by applying proven research techniques.

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Regionally, the global Refracting Telescope market has been classified into different regions such as North America, Latin America, Middle East, Africa, Asia-Pacific, and Africa. Collectively, the overall analysis of the global market helps to make complex business decisions and helps to navigate global clients towards a successful future.

Market Segmentation by Type:

Market Segmentation by Application:

The global Refracting Telescope market report provides detailed elaboration with respect to market dynamics such as drivers, restraints, and opportunities. Industry analysis tools such as SWOT and Porters five techniques have been used for analyzing the global market. Moreover, development plans and policies are also presented in the report.

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Table of Contents:

Chapter 1. Refracting Telescope Market Overview

Chapter 2. Market Competition by Players / Suppliers

Chapter 3. Sales and revenue by regions

Chapter 4. Sales and revenue by Type

Chapter 5. Refracting Telescope Market Sales and revenue by Application

Chapter 6. Market Players profiles and sales data

Chapter 7. Manufacturing Cost Analysis

Chapter 8. Industrial Chain, Sourcing Strategy and Down Stream Buyers

Chapter 9. Market Strategy Analysis, Distributors/Traders

Chapter 10. Refracting Telescope Market effective factors Analysis

Chapter 11. Market Size and Forecast

Chapter12. Conclusion

Chapter13. Appendix

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Widespread Report on the Global Refracting Telescope Market 2020-2028 with the Leading Players Celestron, Vixen Optics, ASTRO-PHYSICS, ORION, Barska,...

UK Part of New NSF Physics Frontier Center Focused on Neutron Star Modeling in ‘Gravitational Wave Era’ – UKNow

LEXINGTON, Ky. (Sept. 1, 2020) The University of Kentucky is part of a new Physics Frontier Center (PFC) that launched today at the University of California, Berkeley. Sponsored by the National Science Foundation (NSF), the Network for Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS)PFC seeks to improve understanding of the most extreme events known in the universe: mergers of neutron stars and their explosive aftermath which includes ripples in space-time known as gravitational waves.

Susan Gardner, professor in the UK Department of Physics and Astronomy in the College of Arts and Sciences, is leading the effort on behalf of UK.

I am really enthusiastic about the new Physics Frontier Center and am delighted at having the chance to participate in it, Gardner said. The ability to detect gravitational waves opens new windows on the study of cold matter at high densities, and the potential for new scientific discoveries is high. I feel that my broad background in nuclear, particleand astrophysics is helpful to making connections within our multi-institution collaboration."

Gardner is currentlyworking with Berkeley postdoc Jeff Berrymanat UK under their existing N3AS consortium to study possible new particle interactions and how they might be probed in this new regime. Sheexpects to address similar topics within the PFC with a future postdoc.

We operate as a single team, combining our expertise in order to tackle the complex multi-physics problems thatarise in astrophysics problems that are beyond the capacity of a single investigator, said Wick Haxton, theoretical nuclear physicist in Berkeley Labs Nuclear Science Division and principal investigator of the PFC.

The center builds upon an NSF-funded research hub in multi-messenger nuclear astrophysics that was established in 2017, and a foundation of support for this field of research by the Office of Nuclear Physics within the U.S. Department of Energys Office of Science. With the upgrade to a Physics Frontier Center, there will now be broader community participation in the effort and an expanded scope of research. The NSF commitment to the N3AS Center will be $10.9 million over five years.

The newly established Network for Neutrinos, Nuclear Astrophysics, and Symmetries Physics Frontier Center will reveal new information about the physics in extreme astrophysical environments, allowing scientists to address major questions in physics and multi-messenger astrophysics, said Jean Cottam Allen, NSF program officer overseeing the Physics Frontier Centers.

Institutional members of the PFC include: UC Berkeley, Los Alamos National Laboratory, North Carolina State University, Northwestern University, Ohio University, Pennsylvania State University, UC San Diego, University of Kentucky, University of Minnesota, University of New Hampshire, University of Notre Dame, University of Washington, and University of Wisconsin, Madison.

Read the full press release at: https://newscenter.lbl.gov/2020/08/17/new-nsf-physics-frontier-center-will-focus-on-neutron-star-modeling-in-gravitational-wave-era/

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UK Part of New NSF Physics Frontier Center Focused on Neutron Star Modeling in 'Gravitational Wave Era' - UKNow

University subject profile: physics – The Guardian

What youll learnPhysics is the study of the fundamental forces that govern our universe. Youll learn about physical phenomena from the largest to the smallest scales, from galaxies to quarks and beyond. Youll also delve into particle physics (the basic building blocks that make up the world around us), and classical and special relativity (how objects act under the effects of forces, and how this changes under extreme conditions).

Its a subject that requires good maths knowledge, as youll be expected to be able to explain the physical world in mathematical terms. You will also get the chance to enhance your computing skills.

Universities offer three- and four-year undergraduate courses. Your course should cover the fundamentals: electromagnetism, quantum and classical mechanics, statistical physics and thermodynamics, and the properties of matter. You could then choose specialist topics, such as astronomy, space science, or applied physics.

By the time you leave university, you will understand key physical laws and principles and be able to solve problems or at least have an idea of how to. You will be able to plan and carry out experiments, and know how to analyse and interpret your findings.

You will also know how to produce clear and accurate scientific reports and present complex information concisely.

How youll learnYoull learn through a combination of lectures, lab sessions and tutorials. Most courses will require you to complete a research project during your fourth year, probably with a research group. Some courses will encourage you to complete work placements.

Entry requirementsMany universities will want top grades, though not all. Many courses are accredited by the Institute of Physics the professional body for physicists. You will probably need to have studied maths and physics at A-level (or equivalent). Further maths, chemistry and computing or computer science are helpful.

What job can you get?Many physics graduates go on to further study and pursue careers in research. Those who leave academia often become data scientists or work in computing or engineering.

The skills you learn in problem-solving and computing will be highly prized by employers in a range of fields. Physics graduates can also be found in the public sector, business and teaching.

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University subject profile: physics - The Guardian

This triple star system warped the protoplanetary discs around it, new research says – CTV News

TORONTO -- New research into a stellar system where three stars compete for attention has unearthed the first evidence that stars can rip apart and warp massive discs of planet-forming material.

Researchers identified a specific star system where planets are not formed on an even plane like in our solar system, but instead on an inclined ring within a warped circumstellar disk around multiple stars, a press release stated.

The system is called GW Orionis, and is located 1,200 light years away in the constellation of Orion.

According to researchers, if you were standing on a planet inside this star system, you could be treated to a double, or even a triple sunset, similar to the iconic Star Wars planet Tatooine.

Published in Science Mag last week, the new observations of GW Orionis provides the first concrete evidence for theoretical models that predicted if the planet-forming disc around a star system was misaligned with the orbital plane of the stars themselves, gravitational forces from the multiple stars could warp the disc and actually break it into rings, something called disc tearing.

An international team led by researchers from the University of Exeter used data from several large telescopes or arrays and a new infrared imager, called MIRC-X, to gain these new insights into the star system.

In star formation, a disk of dust and gas swirls around the growing star, feeding it. Once the star has formed, leftover material within that circumstellar disk forms into planetary bodies and moons.

"We're really excited that our new MIRC-X imager has provided the sharpest view yet of this intriguing system and revealed the gravitational dance of the three stars in the system, said Stefan Kraus, professor of astrophysics at the University of Exeter, in the press release. Normally, planets form around a flat disc of swirling dust and gas yet our images reveal an extreme case where the disc is not flat at all.

"Instead it is warped and has a misaligned ring that has broken away from the disc. The misaligned ring is located in the inner part of the disc, close to the three stars.

Researchers confirmed the existence of this misaligned ring by observing the shadow of the inner ring as it was cast on the rest of the disc.

An artists rendering of the star system shows what looks like a smaller ring of dust and gas tilted in opposition to a more oval disc of material rotating around it.

The inner ring alone contains enough dust and gas to make the mass of Earth 30 times over, meaning it is more than capable of forming planets. If planets could be formed on an inner ring like this, in this star system and others, this means we could see more star systems where planets orbit in increasingly unique ways.

And it could mean there are already planets out there that we havent discovered in star systems were already aware of, on wide and oblique orbits.

"Since more than half of stars in the sky are born with one or more companions, this raises an exciting prospect: there could be an unknown population of exoplanets that orbit their stars on very inclined and distant orbits, Alexander Kreplin, of the University of Exeter, said in the press release.

Its not just the discs of dust and gas that are misaligned with each other, but the stars themselves. The research team observed GW Orionis carefully for more than 11 years, and observed that the orbit of the stars are not on the same plane, but are also misaligned.

The final step for researchers was to take the painstaking observations and load them into computer simulations. This was when it became clear to researchers that they had clear evidence that the discs were torn apart by the competing gravitational forces of the three misaligned stars, proving what had long been only theory.

If three suns, one solar system seems like a familiar scenario, there might be a reason for that.

Its a real-life example of the Three-Body Problem, both a real scientific theory -- a physics and classical mechanics problem trying to track how three objects would move around a single gravitational point -- and a Hugo Award-winning science fiction novel by Chinese writer Liu Cixin that describes the exact scenario occurring in the new research: a star system with three stars in an unstable orbit.

So far, the new research has not predicted an imminent alien invasion to match the events of the novel, so some parts at least, remain science fiction.

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This triple star system warped the protoplanetary discs around it, new research says - CTV News

Scientists discover first ‘intermediate-mass’ black hole in massive merger – Big Think

In May 2019, a ripple of gravitational waves passed through Earth after traveling across the cosmos for 7 billion years. The ripple came in four waves, each lasting just a fraction of a second. Although the ancient signal was faint, its source was cataclysmic: the biggest merger of two black holes ever observed.

It occurred when two mid-sized black holes 66 and 85 times the mass of our Sun drifted close together, began spinning around each other and merged into one black hole roughly 142 times the mass of our Sun.

"It's the biggest bang since the Big Bang observed by humanity," Caltech physicist Alan Weinstein, who was part of the discovery team, told The Associated Press.

A massive bang, sure. But a black hole of this size actually falls within the "intermediate-mass" category, which ranges from about 50 to 1,000 times the mass of our Sun.

Scientists know relatively little about these mid-sized black holes. They've catalogued small black holes only a few times more massive than the Sun, as well as supermassive black holes more than six billion times the mass of our star. But direct evidence of intermediate-mass black holes has remained elusive.

"Long have we searched for an intermediate-mass black hole to bridge the gap between stellar-mass and supermassive black holes," Christopher Berry, a professor at Northwestern University's Center for Interdisciplinary Exploration and Research in Astrophysics), told Northwestern Now. "Now, we have proof that intermediate-mass black holes do exist."

Still, how these middleweight black holes form is a mystery. Scientists know that smaller black holes form when stars explode in violent events called supernovas. But mid-sized black holes couldn't form this way, according to current physics, because stars of a certain mass range undergo a death process called pair instability, where they explode and leave nothing behind, not even a black hole.

This chart compares the mass of black-hole merger events observed by LIGO-Virgo.

Credit: LIGO/Caltech/MIT/R. Hurt (IPAC)

As for supermassive black holes? Scientists are pretty sure that these behemoths, which lie in the center of most galaxies, grow huge by gobbling up ancient dust, gas and other cosmic matter including other black holes. Intermediate black holes may form in a similar way, by small-ish black holes repeatedly merging together.

In other words, an intermediate black hole might be on its way to becoming supermassive.

"We're talking here about a hierarchy of mergers, a possible pathway to make bigger and bigger black holes," Martin Hendry, a professor of gravitational astrophysics and cosmology at Glasgow University, told the BBC. "So, who knows? This 142-solar-mass black hole may have gone on to have merged with other very massive black holes as part of a build-up process that goes all the way to those supermassive black holes we think are at the heart of galaxies."

Visualization of a black hole.

Credit: NASA

The recent discovery sheds light on how black holes form, but questions still remain. Scientists with the LIGO-Virgo collaboration hope to continue studying the newly discovered intermediate black hole dubbed GW190521 in 2021 when the facilities will be up and running again with improved instruments.

"Our ability to find a black hole a few hundred kilometers-wide from half-way across the Universe is one of the most striking realizations of this discovery," Karan Jani, an astrophysicist with LIGO told The Malaysian Reserve.

The discovery was described in two papers published in the Physical Review Letters and The Astrophysical Journal Letters.

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Scientists discover first 'intermediate-mass' black hole in massive merger - Big Think

Scientists detect massive galactic collision between black holes that "aren’t supposed to exist" – Boing Boing

Earlier this week, an international team of scientists from the LIGO Scientific Collaboration and the Virgo Collaboration published two reports one in thePhysical Review Letters, and the other inThe Astrophysical Journal Letters about a strange gravitational wave phenomena they observed.

Approximately 17 billion light-years away from the Earth, a black hole that was 85 times the mass of our sun collided with another black hole that was 66 times the mass of our sun, resulting in a new black hole measured at about 142 solar masses. (If that math doesn't add up in your limited comprehension of astrophysics, that's OK; that's part of why it's so interesting.) Dennis Overbye described the aftermath in the New York Times as being, "eight or so suns' worth of mass and energy [that] disappeared into gravitational waves, ripples of the space-time fabric, in a split-second of cosmic frenzy, ringing the universe like a bell."

That's a pretty remarkable passage of prose. But what's more remarkable about this event is that it challenges our current understanding of how black holes are formed. Also from the Times:

Most known black holes are the corpses of massive stars that have died and collapsed catastrophically into nothing: dark things a few times as massive as the sun. But galaxies harbor black holes millions or billions of times more massive than that. How these objects can grow so big is an abiding mystery of astronomy.

Until recently there had been scant evidence of black holes of intermediate sizes, with 100 to 100,000 solar masses. The black hole created in the GW190521 merger is the first solid example of this missing link.

At least one (if not both) of the colliding black holes was too large to have been formed by a collapsing star; and as far as any scientists are aware, there were never any stars where those black holes had been located.

So the bad news is, black holes can basically smash themselves together and form newer, larger black holes, which can then consume other black holes to continue adding to their masses.

The good news is, if this trend continues, it means we're one step closer to a super-massive hybrid black hole swallowing reality and resetting our timeline back to January 8, 2016 the day that David Bowie released his "Blackstar" album before dying two days later from complications involving another dense mass. Then at least we'll have another chance to make things right.

These Black Holes Shouldn't Exist, but There They Are [Dennis Overbye / The New York Times]

Image: Public Domain via NASA/JPL-Caltech

Lasts week, we lost iconic avant-garde fashion designer, Kansai Yamamoto. Yamamoto is best known for this long-term collaboration with David Bowie, especially the costumes for the Martian rocker's Ziggy Stardust tour. On the Fashion United website, there's a piece about the 2018 Brooklyn Museum evening with Yamamoto, done in support of the David Bowie Is []

This interview presents a conversation with Eisner Award-winning comic book creator Michael Allred (Madman, iZombie, Red Rocket 7, X-Ray Robot, Silver Surfer, X-Statix, Bug! The Adventures of Forager) about BOWIE: Stardust, Rayguns & Moonage Daydreams. Jeffery Klaehn: Please tell me about BOWIE: Stardust, Rayguns & Moonage Daydreams. Michael Allred: It's a visual biography about how []

David Bowie's Let's Dance was released 37 years ago today. His 15th studio record, Let's Dance would become his most commercially successful album but it was not well-received by critics and hardcore fans at the time and Bowie himself would end up regretting the record and the tours and albums that followed (Tonight, Never Let []

While Labor Day is a moment to solemnly consider the role that work serves in all of our lives, there are certain workers among us who will not benefit from a day of celebration and reflection. Robot vacuums, you just keep working like normal this weekend. Look, it's not that we don't appreciate you. But []

Whenever you happen to need a charging cable or a power batteryhey, wait a minute, where did that go? Between the house, your vehicle and all those evildoers that blatantly steal your stuff (otherwise known as family, friends and co-workers), it's tough to keep track of where all your tech accessories are at a moment's []

It's already one of the most iconic items in film history. Unless you've been off-world for the past few years, you already know all about the all-powerful Infinity Gauntlet. It's the weapon wielded by the Mad Titan Thanos in his quest to reshape the cosmos in the Marvel Cinematic Universe, culminating in a heart-stopping smackdown []

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Scientists detect massive galactic collision between black holes that "aren't supposed to exist" - Boing Boing

Looking skin deep at the growth of neutron stars – Washington University in St. Louis Newsroom

In atomic nuclei, protons and neutrons share energy and momentum in tight quarters. But exactly how they share the energy that keeps them bound within the nucleus and even where they are within the nucleus remain key puzzles for nuclear scientists.

A new study by researchers at Washington University in St. Louis and Lawrence Livermore National Laboratory (LLNL) in California tackled these questions by leveraging data from nuclear scattering experiments to make stringent constraints on how nucleons (neutrons and protons) arrange themselves in the nucleus. The research appears in two corresponding papers in Physical Review C and Physical Review Letters.

Robert J. Charity, research professor of chemistry, Willem H. Dickhoff, professor of physics, and Lee G. Sobotka, professor of chemistry and of physics, all in Arts & Sciences, are co-authors on the papers led by Cole Pruitt, presently a postdoctoral fellow at LLNL, who earned his PhD at Washington University in 2019. Pruitt completed the majority of the work for these papers as part of his thesis effort.

Their analysis shows that for several cornerstone nuclei, a tiny fraction of the protons and neutrons possess the lions share of the overall energy that keeps them bound in nuclei, roughly 50% more than expected from standard theoretical treatments.

Further, the study makes new predictions for the neutron skin a region where extra neutrons pile up of several neutron-rich nuclei. In turn, these predictions are tightly connected to how large neutron stars grow and what elements are likely synthesized in neutron star mergers.

Our results quantitatively indicate how asymmetry, charge and shell effects contribute to neutron skin generation and drive a disproportionate share of the total binding energy to the deepest nucleons, Pruitt said.

Understanding how nuclear asymmetry energy changes with density is an essential input to the neutron equation-of-state, which determines neutron star structure. But its not easy to directly measure neutron skins.

A comprehensive model should not only reproduce integrated quantities (like the charge radius or total binding energy) but also specify how nucleons share momentum and energy, all while being realistic about the model uncertainty of its predictions, Pruitt said.

The work reported by Pruitt and collaborators provides a powerful bridge between nuclear physics and astrophysics in the new era of multi-messenger astronomy. The measurement of the neutron skin of several nuclei reported in the letter (Physical Review Letters) could provide stringent constraints on the equation of state of neutron-rich matter, which is a critical ingredient for understanding neutron stars, said Jorge Piekarewicz, professor of physics at Florida State University, a leading theorist who was not involved in these studies.

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Looking skin deep at the growth of neutron stars - Washington University in St. Louis Newsroom

China’s secretive ‘space plane’ makes successful return to Earth – CNET

China's reusable experimental spacecraft, rumored to be a space plane like the above, spent two days in orbit, according to Chinese state-run media outlets.

China's "reusable experimental spacecraft" has successfully returned to Earth after spending two days in low-Earth orbit. The secretive mission released an unknown object during its time in space and marks an "important breakthrough" in the country's reusable spacecraft research program, according to Chinese state-run Xinhua media outlet.

The spacecraft launched from the Jiuquan Satellite Launch Center in northwest China on Friday, atop a Long March 2F rocket. It is believed to be a space plane similar to the US Air Force X-37B but no images of the launch or return have been released. The veil of secrecy have led some space-watchers to suggest it could be a military space plane.

Subscribe to the CNET Now newsletter for our editors' picks of the most important stories of the day.

On Monday, the People's Daily Science account on Twitter posted a brusque update, echoing the sentiments published by Xinhua. No details of the landing time or site have been released.

According to Andrew Jones, a journalist covering China's space program, further flights are expected to follow the initial test launch and, quoting Chen Hongbo, an official with China Academy of Launch Vehicle Technology, he suggests the new vehicle may be able to fly "more than 20 times."

The reusable space plane is believed to be more Space Shuttle than SpaceX. It launches vertically but lands horizontally, coasting onto a runway during its return to Earth. Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, and other internet sleuths suggest the experimental spacecraft may have landed at an airbase in the Taklamakan desertin northwest China.

Monday also saw China launch a Long March 4B rocket from the Taiyun Satellite Launch Center in northern China. The rocket's first stage booster came crashing back to Earth shortly after launch, with harrowing footage uploaded to Chinese social media site Weibo of the booster exploding near a school.

Launches you may be familiar with in the US, such as those conducted by SpaceX and NASA, take place close to the coast, but China often launches from inland sites, resulting in debris falling back to Earth over populated areas which sometimes have to be evacuated prior to launch.

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China's secretive 'space plane' makes successful return to Earth - CNET

The End of the Universe Will Probably Be Fairly Disappointing – WIRED

Katie Mack, an assistant professor of physics at North Carolina State University, is quickly becoming one of the internets most popular science communicators. In her first book, The End of Everything (Astrophysically Speaking), she explores various scenarios for the end of the universe.

I noticed that when I gave public talks and talked about the end of the universe, that was something that people got really excited about, Mack says in Episode 430 of the Geeks Guide to the Galaxy podcast. It was something that I thought I could have a lot of fun with, and I did. I really enjoyed writing this book.

Science fiction writers have long been fascinated by the end of the universe, and both Tau Zero by Poul Anderson and The Restaurant at the End of the Universe by Douglas Adams involve characters who witness the end of everything. Both of those books, published in 1970 and 1980 respectively, assume a Big Crunch model of cosmology.

The Big Crunch would be interesting to see, Mack says. The expansion of the universe stops, and reverses, and everything comes crashing back together. It would be kind of a neat light show, though it would also be super-lethal for anything thats out there.

Unfortunately for science fiction fans, the current thinking among scientists is that the end of the universe will be pretty boring. Were probably not going to have a Big Crunch, Mack says. Its probably going to be the Heat Death, where the universe just continues to expand and expand, and things sort of fade away. So in principle it might not end up being that interesting, because youd get there and all there is is just lots of cold, dark, empty space.

Given that the end of the universe will be sort of a letdown, Mack says a journey to the near future sounds far more appealing.

Id much rather see a hundred years from now, and then a thousand years from now, and kind of step forward that way, and not go straight to the ending, because I dont think the ending is going to be fun.

Listen to the complete interview with Katie Mack in Episode 430 of Geeks Guide to the Galaxy (above). And check out some highlights from the discussion below.

Katie Mack on the Star Trek episode Remember Me:

Very strange things are happening on the ship, and people are disappearing, and the universe seems to be getting smaller around [Dr. Crusher]. Shes a doctor, so she knows that she could be hallucinating all this, and so she does diagnostics on herself and theres nothing wrong, her mind is working perfectly. So she concludes that if theres nothing wrong with her, there must be something wrong with the universe. I use that as a way to introduce the possibility that the reason we find the force of gravity to be so weak is not that theres something wrong with gravity per se, but that the universe might be a different shape than we anticipatedmight have a different number of dimensions than we anticipatedand that could be why gravity seems so weak. So its not something wrong with gravity, its something wrong with the universe.

Katie Mack on social media:

Once in a while a tweet goes viral, and then a whole bunch of people see it and a whole bunch of people follow you. The biggest example of that was in 2016 where somebody was complaining about climate change, and tweeted to me about it, and I replied to that in a way that got a lot of attention. I had been tweeting about how climate change is depressing, basically, and somebody replied and said that climate change is a scam, and said, You should go learn some science. So I replied that I already got a PhD in astrophysics, and more than that seems like it would be overkill. Somehow that got picked up by a bunch of people and retweeted a whole lot, and then J.K. Rowling took a screenshot of it and posted it on her feed, and that just blew up my Twitter. I think my following doubled in a week.

Katie Mack on long-term survival:

In only about 4 billion years the Andromeda Galaxy will collide with this one, which will make a messitll move the orbits of stars around, and therell be some new star formation, and the supermassive black holes will merge, and that could cause some jets of high-energy radiation, but it wont necessarily affect the solar system all that much. Itll move where we are in the galaxy, and change our night sky, but its not going to hurt us, necessarily. Even the amount of star formation that youll get out of that collisionitll be enough to set off some new supernovae, but it wont necessarily hurt us. So I think we can survive that pretty easily, and then after that its just a matter of slow cooling, where everythings just kind of fading away for billions and billions and billions of years.

Katie Mack on Freeman Dyson:

You want to use less and less energy over time, because youre going to have access to less and less energy as the universe is expanding and cooling. The whole point of [Dysons] exercise was to figure out if there was a way to slow down your processes as the universe is expanding, to the point that you can live technically foreverits just that over time each thought gets farther and farther apart. That would work if the universe were expanding linearly, meaning that it was not speeding up in its expansion, but we know now that the universe is speeding up in its expansion, and that does mess up that plan, in a kind of complicated way. So that doesnt work indefinitely, but it can still buy you some time, if you need to just conserve resources over a very long period of time in the cosmos.

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The End of the Universe Will Probably Be Fairly Disappointing - WIRED

New High-Res Images of The Sun Show How Creepy Sunspots Look in Closeup – ScienceAlert

One of the most powerful solar observatories in the world has just completed a major upgrade. And now, the GREGOR solar telescope in Spain has taken some of the most high-resolution images of our Sun ever obtained in Europe.

In the upgraded telescope's new images, details as small as 50 kilometres (31 miles) across can be discerned amid the roiling activity on the surface of the Sun.

"This was a very exciting, but also extremely challenging project," said physicist and GREGOR lead scientist Lucia Kleint of the Leibniz Institute for Solar Physics (KIS). "In only one year we completely redesigned the optics, mechanics, and electronics to achieve the best possible image quality."

GREGOR (left) and its redesigned optics (right). (KIS)

Interestingly, while COVID-19 lockdowns have been a hindrance to scientific research, in this instance, they proved helpful. According to a post on the KIS website, scientists were stranded at the observatory during the March lockdown in Spain. Rather than waste the time, they got to work setting up the optical laboratory.

They were able to correct two significant problems introduced by a pair of mirrors, coma and astigmatism, that resulted in blurred and distorted images. Because of the design of the optics laboratory, and the limited space therein, these mirrors had to be completely replaced with off-axis parabolic mirrors, polished to a precision within 1/10,000th the width of a human hair.

Snowstorms hindered observations for a while then, but when Spain reopened in July, the first thing the GREGOR team did was fire up their upgraded telescope.

(KIS)

The new first light images show solar granules, the tops of convection cells in the solar plasma. The middle of each granule is lighter; that's where hot plasma rises from below. This plasma moves outwards as it cools, then falls back into the depths at the darker edges of each granule.

They look a little bit like popcorn, but don't be fooled - a typical granule is about 1,500 kilometres (930 miles) across, just over 10 percent of the diameter of Earth.

Another image and video show the lone sunspot that graced the face of the Sun on 30 July 2020. This is a temporary region where the Sun's magnetic field is particularly strong, inhibiting the Sun's normal surface convection activity; it appears darker on the surface of the Sun because it is cooler than the material around it.

(KIS)

These sunspot regions are of intense interest to us, because these magnetic field lines snap, tangle and reconnect. That magnetic reconnection results in the release of copious amounts of energy, producing solar flares and coronal mass ejections - a phenomenon that can affect us here on Earth, disrupting satellite navigation and communication.

Images like those obtained by GREGOR, and other high-resolution solar observatories such as the Daniel K. Inouye Solar Telescope in Hawaii, with a resolution of 30 kilometres, along with the Big Bear Solar Observatory in the US, can help us to better understand these solar processes.

Plus, we'll never get tired of looking at the mind-blowing images of the surface of our Sun.

A paper describing the telescope's upgrade has been published in Astronomy & Astrophysics.

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New High-Res Images of The Sun Show How Creepy Sunspots Look in Closeup - ScienceAlert

Indian astronomers discover one of the farthest star galaxies in universe – Livemint

Indian astronomers have discovered one of the farthest star galaxies in the universe, estimated to be located 9.3 billion light years away from Earth, announced Department of Space, Indian Government.

This is a landmark achievement for country's first Multi-Wavelength Space Observatory "AstroSat."

Sharing this information, Union Minister of State (Independent Charge), Development of North Eastern Region (DoNER), MoS PMO, Personnel, Public Grievances, Pensions, Atomic Energy and Space, Dr Jitendra Singh said, "The galaxy called AUDFs01 was discovered by a team of Astronomers led by Dr Kanak Saha from the Inter-University Centre for Astronomy and Astrophysics(IUCAA) Pune."

The importance and uniqueness of this original discovery can be made out from the fact that it has been reported in the international journal Nature Astronomy" published from Britain.

India's AstroSat/UVIT was able to achieve this unique feat because the background noise in the UVIT detector is much less than one on the Hubble Space Telescope of US based NASA, the statement read.

Dr Jitendra Singh congratulated Indias Space Scientists for once again proving to the world that Indias capability in Space technology has risen to a distinguished level from where our scientists are now offering cues and giving leads to the Space scientists in other parts of the world. According to Professor ShyamTandon, the excellent spatial resolution and high sensitivity is a tribute to the hard work of the UVIT core team of scientists for over a decade.

According to Director of Inter-University Centre for Astronomy and Astrophysics (IUCAA) Dr Somak Ray Chaudhury, this discovery is a very important clue to how the dark ages of the Universe ended and there was light in the Universe. We need to know when this started, but it has been very hard to find the earliest sources of light, he said.

Pertinent to mention that Indias first Space Observatory AstroSat, which has made this discovery, was launched by the Indian Space Research Organization (ISRO) on September 28, 2015 during the first term of the Modi Government. It was developed by a team led by ShyamTandon, Ex Emeritus Professor, IUCAA with the full support of ISRO.

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Indian astronomers discover one of the farthest star galaxies in universe - Livemint

Zooming In Tight on Dark Matter Equivalent of Being Able to See a Flea on the Surface of the Moon – SciTechDaily

Projected dark matter density map, created using a simulation measuring 2.4 billion light years on each side. The inset square (bottom left) is the deepest zoom in the simulation: it is only 783 light years across, equivalent to 500 times the size of the solar system. In the inset square, the smallest clearly visible dark matter haloes have a mass comparable to that of the Earth (0.000003 the mass of the Sun). Credit: Dr. Sownak Bose, Center for Astrophysics, Harvard University

Cosmologists have zoomed in on the smallest clumps of dark matter in a virtual universe which could help us to find the real thing in space.

An international team of researchers, including Durham University, UK, used supercomputers in Europe and China to focus on a typical region of a computer-generated universe.

The zoom they were able to achieve is the equivalent of being able to see a flea on the surface of the Moon.

This allowed them to make detailed pictures and analyses of hundreds of virtual dark matter clumps (or haloes) from the very largest to the tiniest.

Dark matter particles can collide with dark matter anti-particles near the center of haloes where, according to some theories, they are converted into a burst of energetic gamma-ray radiation.

Their findings, published in the prestigious journalNature, could mean that these very small haloes could be identified in future observations by the radiation they are thought to give out.

An artists impression of dark matter haloes with various mass in the Universe. Credit: YU Jingchuan, Beijing Planetarium

Co-author Professor Carlos Frenk, Ogden Professor of Fundamental Physics at the Institute for Computational Cosmology, at Durham University, UK, said: By zooming in on these relatively tiny dark matter haloes we can calculate the amount of radiation expected to come from different sized haloes.

Most of this radiation would be emitted by dark matter haloes too small to contain stars and future gamma-ray observatories might be able to detect these emissions, making these small objects individually or collectively visible.

This would confirm the hypothesized nature of the dark matter, which may not be entirely dark after all.

Most of the matter in the universe is dark (apart from the gamma radiation they emit in exceptional circumstances) and completely different in nature from the matter that makes up stars, planets, and people.

The universe is made of approximately 27 percent dark matter with the rest largely consisting of the equally mysterious dark energy. Normal matter, such as planets and stars, makes up a relatively small five percent of the universe.

Galaxies formed and grew when gas cooled and condensed at the center of enormous clumps of this dark matter so-called dark matter haloes.

Astronomers can infer the structure of large dark matter haloes from the properties of the galaxies and gas within them.

The biggest haloes contain huge collections of hundreds of bright galaxies, called galaxy clusters, weighing a 1,000 trillion times more than our Sun.

Projected dark matter density map, created using a simulation measuring 2.4 billion light years on each side. . The intermediate square (top right) is just under a million light years across. The smallest square (bottom left) is the deepest zoom: it is only 783 light years across, equivalent to 500 times the size of the solar system. In the intermediate square(top right) the largest dark matter haloes have a mass similar to that of a rich galaxy cluster (a million trillion times the mass of the Sun). In the smallest square (bottom right) the smallest clearly visible haloes have a mass comparable to that of the Earth (0.000003 the mass of the Sun). Credit: Dr. Sownak Bose, Center for Astrophysics, Harvard University

However, scientists have no direct information about smaller dark matter haloes that are too tiny to contain a galaxy. These can only be studied by simulating the evolution of the Universe in a large supercomputer.

The smallest are thought to have the same mass as the Earth according to current popular scientific theories about dark matter that underlie the new research.

The simulations were carried out using the Cosmology Machine supercomputer, part of the DiRAC High-Performance Computing facility in Durham, funded by the Science and Technology Facilities Council (STFC), and computers at the Chinese Academy of Sciences.

By zooming-in on the virtual universe in such microscopic detail, the researchers were able to study the structure of dark matter haloes ranging in mass from that of the Earth to a big galaxy cluster.

Surprisingly, they found that haloes of all sizes have a very similar internal structure and are extremely dense at the center, becoming increasingly spread out, with smaller clumps orbiting in their outer regions.

The researchers said that without a measure scale it was almost impossible to tell an image of a dark matter halo of a massive galaxy from one of a halo with a mass a fraction of the Suns.

Co-author Professor Simon White, of the Max Planck Institute of Astrophysics, Germany, said: We expect that small dark matter haloes would be extremely numerous, containing a substantial fraction of all the dark matter in the universe, but they would remain mostly dark throughout cosmic history because stars and galaxies grow only in haloes more than a million times as massive as the Sun.

Our research sheds light on these small haloes as we seek to learn more about what dark matter is and the role it plays in the evolution of the universe.

###

Reference: Universal structure of dark matter haloes over a mass range of 20 orders of magnitude by J. Wang, S. Bose, C. S. Frenk, L. Gao, A. Jenkins, V. Springel and S. D. M. White, 2 September 2020, Nature.DOI: 10.1038/s41586-020-2642-9

The research team, led by the National Astronomical Observatories of the Chinese Academy of Sciences, and including Durham University, UK, the Max Planck Institute for Astrophysics, Germany, and the Center for Astrophysics in Harvard, USA, took five years to develop, test and carry out their cosmic zoom.

The research was funded by the STFC, the European Research Council, the Chinese Academy of Sciences, the Max Planck Society and Harvard University.

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Zooming In Tight on Dark Matter Equivalent of Being Able to See a Flea on the Surface of the Moon - SciTechDaily

Space discoveries that will blow your mind | News | helenair.com – Helena Independent Record

The size of the universe is hard to fathom, and its expanding even fasterthan scientists originally thought. While humans will never map out the entirety of space, that doesnt stop them from exploring it. The National Aeronautics and Space Administration (NASA) has been around since 1958.Japan, Russia, and Francejust to name a few countriesall have space agencies dedicated to exploring the final frontier.

Since NASAs inception in 1958, astronauts have landed on the moon, parked a robot-controlled rover on Mars, and discovered thousands of exoplanetsplanets that orbit stars outside of this solar system. Scientists can even explore the 95% of invisible spacecomprised of dark energy, dark matter, and dark radiation. Each year on the first Friday in May, the United States observes National Space Day in honor of the remarkable achievements already made and those still to come in our continued exploration of space. To celebrate our many milestones in this arena, Stacker compiled a list of 30 mind-blowing space discoveries after searching news archives and reports from NASA. Click through to see what theyve uncoveredfrom a super-Earth and sun twins to the first photograph of a black hole.

You may also like: 1 million species are facing annihilationinside Earth's sixth mass extinction event

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Space discoveries that will blow your mind | News | helenair.com - Helena Independent Record

Astronomers Spot a Black Hole so Massive They Werent Sure it Could Exist – Gizmodo Australia

One of the greatest things about being an astrophysicist is that you keep discovering things you didnt think were possible. Now the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo Observatory have discovered their largest black hole yet. Its important because scientists had in fact doubted whether black holes of this mass could even exist.

After months of painstaking analysis, the team has just reported their discovery in papers in the Physical Review Letters and the Astrophysical Journal Letters.

The black hole was discovered because its merger with a slightly less massive companion emitted gravitational waves. These are ripples in spacetime that can be detected on Earth the echoes of violent cosmic collisions that, in this case, happened billions of years ago.

The finding is hugely important from a research perspective. It also settles a bet among astrophysicists. In February 2017, a number of us met at the Aspen Center for Physics in Colorado, USA. We were excited to be discussing the results that we already had from LIGO. But we were also looking forward to future discoveries and arguing about how pairs of black holes actually merge.

There were multiple ideas under discussion. One was that pairs of massive stars gradually evolve side by side until both collapse into black holes and ultimately merge. Another was that previously unacquainted black holes can be brought together by the jostling of a crowd of other stars in dense stellar regions. But which is the main process? I got several participants together to make a wager, as shown on the photo below.

Sourav Chatterjee (now at Tata. Institute of Fundamental Research, India); Carl Rodriguez (Carnegie Mellon University, USA); me; Daniel Holz (University of Chicago, USA); Chris Belczynski (Nicolaus Copernicus Astronomical Center, Poland). Author provided

At the end of their lives when stars run out of nuclear fuel and no longer have the support pressure to counter their own gravity they collapse. Low-mass stars, including our Sun, eventually become faint stellar ghosts known as white dwarfs. Stars that started out heavier than about eight times the mass of the Sun become incredibly dense and small objects called neutron stars. And really massive stars of more than 20 solar masses at birth become black holes, with final masses between a few and around 40 solar masses.

But something weird has long been conjectured to happen to very, very massive stars, perhaps those with initial masses between around 130 and 250 solar masses, whose centres get really hot (around a billion degrees Kelvin) late in their evolution. The light bouncing around inside these stars, and providing much of the pressure support, is so energetic that it can transform into pairs of electrons and positrons (positrons are the antimatter counterparts of electron they are nearly identical but have opposite charge).

This, in turn, makes the star unstable: the pressure suddenly drops, the centre of the star contracts and heats up, and runaway nuclear fusion causes the entire star to explode in a bright pair-instability supernova, leaving no remnant behind.

This means that, if all black holes in merging pairs were created by collapsing stars, there should be no black holes with masses between around 55 and 130 solar masses the stars that could have produced such remnants would have ended their lives in explosions that leave nothing behind. More massive black holes, however, can be formed from even heavier stars (of more than 250 solar masses) which do not undergo the same runaway nuclear fusion, and collapse completely into black holes.

But this wouldnt be the case for black holes merging in a crowd. When two black holes merge, they create another black hole, almost as heavy as the sum of their masses. If this black hole remains in the dense environment it can merge again, giving rise to even more massive black holes of a range of sizes, filling in the mass gap. This is what brought us to signing this bet in Aspen: would we find a merging black hole with mass between around 55 and 130 solar masses or not?

GW190521 is a merger of two very massive black holes indeed, the heaviest of any observed so far through gravitational waves. The heavier one, measured to be between 71 and 106 solar masses (at 90 per cent confidence), falls squarely into the mass gap. This seems to suggest that black holes do indeed repeatedly merge.

The merged hole had a final mass of 142 times that of the sun, making it the largest of its kind observed in gravitational waves to date. LIGO/Caltech/MIT/R. Hurt (IPAC).

I was not involved in this marvellous measurement. But by afortuitous coincidence I had the opportunity to referee one of the discovery papers, meaning that I am now well-prepared to perform my duties as arbiter of the bet. My first order of business is to adjudicate the wager in favour of Chatterjee and Rodriguez as well as Fred Rasio of Northwestern University, US, who joined the ultimate winners in an addendum after the original bet was signed.

The bet. Author provided

Congratulations to the deserved winners and may they enjoy the wineowed to them, and the pleasure of being proved right. The bet being resolved, my next to-do item, along with many other astrophysicists around the world, is to start thinking about the implications of this revolutionary observation.

Is this the definitive demonstration of black holes merging repeatedly in a dense cluster of stars? Could we have incorrectly estimated the boundaries of the mass gap because of uncertainty in key nuclear reactions? Could the merger have happened in completely different ways we havent even thought of?

The LIGO-Virgo teams have yet again done an amazing job with theirinstruments and data analysis, obtaining a wonderfully unexpected result.For the rest of the astrophysics community, the fun of making sense of it is only just beginning. Which is why, in such scientific bets, everybody really is a winner.

Ilya Mandel, Honorary Professor of Theoretical Astrophysics, University of Birmingham

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Astronomers Spot a Black Hole so Massive They Werent Sure it Could Exist - Gizmodo Australia

Warped gas disc torn apart by three stars directly observed for the first time – ZME Science

Astronomers have discovered a spectacular first in terms of star clusters and planet-forming discs of gas, a systemGW Orioniswith a warped disc with torn out inner rings. The team believes that the discs odd shape which defies the common view of a flat plane orbiting planets and gas discswas created when the misalignment of the three stars at the centre of the disc caused it to fracture into distinct rings.

As well as being extraordinary in its own right, the astronomers believe that the warped disc could harbour exotic and strange exoplanetsnot unlike Tatooine in Star Wars series which formed within the inclined rings and are, for now, hidden from view.

The idea that planets form in neatly-arranged, flat discs around young stars goes back to the 18th century and Kant and Laplace, research team-leader Stefan Kraus, a professor of astrophysics at the University of Exeter in the UK, tells ZME Science.Our images reveal an extreme case where the disc is not flat at all, but is warped and has a misaligned ring that has broken away from the disc.

Tatooine planets that orbit around 2 or 3 suns have already been envisioned by science fiction and some Tatooine exoplanets have already been found. Here, we observe how such planets form and find that they can form on extreme, highly inclined orbits in configurations that are completely different from the neat arrangement observed in the Solar System.

The team saw the warped shape of the system GW Orionis, which sits 1300 light-years from Earth in the constellation of Orion, in observations made by the Very Large Telescope (VLT) operated by European Southern Observatory (ESO), and the Atacama Large Millimeter/ submillimeter Array (ALMA) based in the Chilean desert. But, properly envisioning this shape and its cause meant studying the system for a staggering 11 years.

The most important result from our study is that we can identify the cause for the misalignments and link it to the disc tearing effect that has been proposed by theorists 8 years ago, but has not been observed so far, Kraus continues. For this, it was essential to measure the orbital motion of the three stars that are in the centre of the system over their full 11-year orbital period.

We found that the three stars do not orbit in the same plane, but their orbits are misaligned with respect to each other and with respect to the disc.

We have observed GW Orionis, a triple star system surrounded by a planet-forming disc, with several different telescopes including the VLT and ALMA. After observing the three stars for several years, our team was able to calculate the orbits very accurately, team member Alison Young of the Universities of Exeter and Leicester tells ZME Science. This data allowed us to build a detailed computer model of the system, which predicted that the disc would be bent and even torn to form a separate inner ring.

A couple of years later when we received the data back from the VLT and ALMA, the image of a disc bent and even torn to form a separate inner ring, were stunning.

A paper detailing their work is published in the journal Science.

The images of GW Orionis that the astronomers collected represent the first visualisation of disc-tearing ever captured by researchers. This tearing and the warped effect it created marks this out as a planetary system exceptionally different from the solar system.

The radial shadows in the VLT SPHERE image are clear evidence that the ring is tilted. To form a narrow shadow like this on the disc you need a fairly opaque ring of material that is at an angle to the disc surface blocking the starlight, Young explains. This result is consistent with some modelling done by members of the team which worked out the most likely orientations of the components of the system.

This system is unusual because the orbits of the three stars are misaligned, unlike the planets in the solar system they do not orbit in the same plane, and these stars host a large disc that is also tilted relative to their orbits, Young continues. We see all sorts of intriguing structures now in images of protoplanetary discs but this is the first direct evidence of the disc tearing effect.

The observations also gave the researchers an idea of the vast scale of the GW Orionis disc.

The ring harbours about 30 Earth masses of dust, which is likely sufficient for planet formation to occur in the ring. Any planets formed within the misaligned ring will orbit the star on highly oblique orbits and we predict that many planets on oblique, wide-separation orbits will be discovered in future planet imaging surveys.

As well as being able to reconstruct the torn disc of GW Orionis from the ALMA data in conjunction with data collected from several other telescopes, the team has been able to piece together the process by which this tearing likely occurred. They conclude that it could be a result of those three, misaligned stars. Something that initially came as a surprise to the astronomers.

One very intriguing aspect of GW Orionis is that the orbits of the stars are strongly misaligned with respect to each other, and they are also strongly titled with respect to the large-scale disc. This wasnt clear at the time when we started the study and became only apparent after monitoring the orbit motion for the full 11-years orbital period.

Alison Young explains that because the disc surrounds three stars and the orbits of those stars are misaligned with respect to each other, the gravitational pull on the disc is not the same all the way around. This means that the gas and dust orbiting in the disc around all three stars feels a different force at different positions in the disc. This is what tears the disc apart into separate rings.

Our study shows that the strong distortions observed in the disc such as the warp and torn-away ringcan be explained by the conflicting gravitational pull from the 3 stars. The key aspect is that the orbits are strongly misaligned with the disc.

One interesting consequence of the warping of this gas and dust is that fact that it will wrap rings of material around any planets forming within it. This tearing also has a marked effect on these exoplanets orbits. This leads to conditions that would make the exoplanets in the GW Orionis system significantly different from planets in our own solar system.

The planets in our solar system all have more-or-less aligned orbits. Any planets that form in the warped disc or misaligned ring could have highly inclined orbits, says Young. Further out, the disc is flatter and any planets that form there are likely to orbit in a similar plane to the disc. Of course, any planets that form in the GW Orionis system will also have three suns!

Kraus points out that planets with oblique orbits have been identified beforeparticularly in the case of Hot Jupitersplanets with a mass and size comparable to the solar systems largest planet, but that orbit closer to their star and transit across its face.

Hot Jupiters orbit their stars very close in, and it is clear that they have not formed on the oblique orbits were we observe them. Instead, they must have been moved onto these orbits through migration processes, Kraus says. We havent found yet any long-period planets on oblique orbitscomparable to Earth or Jupiter. However, our research shows that such planets could form in the torn-apart rings around multiple systems.

Given that about half of all stars are found in multiple systems, there could be a huge population of such long-period planets with high obliquity.

Existing under the glare of three suns would make the planets in the GW Orionis system similar in some ways to an exoplanet discovered by astronomers from the University of Arizona in 2016.

The young exoplanet HD 131399Ab, 340 light-years from Earth in the constellation Centaurus, has a scorching hot temperature of around 580 C and exists in a state of constant daytime. It too has been compared to the planet of Tatooine from the Star Wars series. But Straus believes the planets in GW Orionis could be much cooler than thisor could alternate between cool and hot climates.

Planets on such orbits could have stable atmospheric conditions, but would be ice worlds with low temperatures on their surfaces, Kraus says. Planets that might have formed in the circumstellar/ circumbinary disc would experience extreme temperature variations, depending on where they are on their orbit.This should result in a strongly variable climate.

Questions still remain about the GW Orionis system especially in light of research from another team who investigated the system with the ALMA telescope. This work-published in The Astrophysical Journal Letters earlier this year suggests that our understanding of how the disc became warped is missing a vital component. We think that the presence of a planet between these rings is needed to explain why the disc tore apart, says Jiaqing Bi of the University of Victoria, Canada, lead author of a paper.

Speaking to ZME Science exclusively, Kraus addresses this earlier research: This alternative scenario, where a yet-unseen planet located between the inner and middle ring might be the cause for the unusual disc shape, is more speculative, as such as planet has not been found yet, the astrophysicist says. Also, the papers authors had less information on the 3-dimensional shape of the disk as their ALMA observations had 6x lower solution and they did not have scattered-light images showing the shadows. Plus, they did not know the full orbits.

Young continues by adding one future question regarding GW Orionis she would like to see answered also concerns the mechanism that caused the warping of the as and dust planet-forming disc.

An important question we need to look at is how these systems came to be misaligned in the first place. Was the disc formed with the stars, did the material forming the disc arrive later, or did the system get disrupted at some point?

Think of a star as a spinning top tilted at an angle, the researcher suggests. We want to find out how tilted the stars are so we can check whether a stars tiltor spin axis matches the tilt of its disc, or if the stars in a binary or triple system have the same or different tilts.

Some members of the team that made this discovery are currently developing a technique for measuring the spin axis of stars which could massively aid the understanding of how these systems formed.

Remembering that whilst this is not the first system discovered with such a warped disc, it is the first with a directly observed torn disc. This means the key to answering lingering questions likely lies in the direct observation of more systems that share features with GW Orionis.

There are a few planet-forming discs that show some evidence of warping but for these, it is unclear what is causing the effect or there is an alternative scenario that can explain the observations, that has not been ruled out yet, adds Young. This is the first time that disc tearing has been directly observed and the only system so far for which we can link the structure with the physical mechanism behind it.

Young suggests that the results of a larger survey performed by the ALMA array could provide clearer information about the motion of gas in planet-forming discs and their chemical composition, thus helping the team gather more information about the GW Orionis disc.

We would like to obtain high-resolution observations of molecular emission from GW Orionis to shed more light on the motion of the gas in the disc and perhaps reveal any planets that are forming, she explains. Of course, we also are keen to understand if there are differences in how planets might form in warped discs compared to flat discs around a single star and we will be working on new computer models to look at this, using what we have learned from our observations.

Young explains the importance of the GW Orionis images the team captured, whilst focusing on one image that for her, brought home the significance of the investigation in which she played a part.

I find the SPHERE image [above left] in particular amazing because we can really see the disc is a 3-dimensional structure with a surface covered in bumps and shadows. We are looking at what could eventually become an unusual type of planetary system in the very process of forming.

For Stefan Kraus, the beauty of investigating a system such as GW Orionis is the wonder to imagining what it is like to stand on the surface of such a world and stare up into sky. Kraus concludes: Half of the sky would be covered by a massive disc warp that is being illuminated by the 3 stars, intercepted by narrow shadows that are cast by the misaligned disc ring.

I find it fascinating to imagine how the sky would look like from any planet in such a system one would see not only the 3 stars dancing around each other at different speeds but also a massive dust ring extending over the whole firmament.

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Warped gas disc torn apart by three stars directly observed for the first time - ZME Science

How neutrons and protons arrange themselves in the nucleus? – Tech Explorist

The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom. Protons and neutrons are bound together to form a nucleus by the nuclear force. But precisely what keeps them bound within the nucleus and even where they are within the nucleus remains key puzzles for nuclear scientists.

In an effort ti figure out the answers, scientists at Washington University in St. Louis and Lawrence Livermore National Laboratory (LLNL) in California- leveraged data determine how nucleons (neutrons and protons) arrange themselves the nucleus.

They found that for several cornerstone nuclei, a tiny fraction of the protons and neutrons possess most of the overall energy that keeps them bound in nuclei, generally 50% more than expected from standard theoretical treatments.

The study also made new predictions for the neutron skin a region where extra neutrons pile-up of several neutron-rich nuclei. Thus, these predictions are firmly associated with how enormous neutron stars grow and what elements are likely synthesized in neutron star mergers.

The quantitatively demonstrates how asymmetry, charge, and shell impacts add to neutron skin generation and drive a disproportionate share of the total binding energy to the deepest nucleons.

Cole Pruitt, presently a postdoctoral fellow at LLNL, who earned his Ph.D. at Washington University in 2019, said,A comprehensive model should not only reproduce integrated quantities (like the charge radius or total binding energy) but also specify how nucleons share momentum and energy, all while being realistic about the model uncertainty of its predictions.

Jorge Piekarewicz, professor of physics at Florida State University, said,The work reported by Pruitt and collaborators provides a powerful bridge between nuclear physics and astrophysics in the new era multi-messenger astronomy. The measurement of the neutron skin of several nuclei reported in the letter (Physical Review Letters) could provide stringent constraints on the equation of state of neutron-rich matter, which is a critical ingredient for understanding neutron stars.

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How neutrons and protons arrange themselves in the nucleus? - Tech Explorist

Kentucky by Heart: Many Kentuckians have made their mark in fields of science and technology – User-generated content

By Steve FlairtyNKyTribune Columnist

Science and technology. . .in the Bluegrass State??

Over the years, Kentucky hasnt always been given credit for its part in the furtherance of science and technology in the U.S., but after I did a little research this week, I discovered that the state has some real credibility in the area. There are a goodly number of people born in Kentucky who have been, or are, important participants in the fields as scientists or inventors.

Dr. Lee Todd (Photo from University of Kentucky)

For sure, my research is quite limited, especially regarding women excelling in this area. I would love to hear from my readers offering an expanded list.

Ive had the joyful experience to cross paths a few times with Dr. Lee Todd, Jr., former University of Kentucky president, born in the small town of Earlington, in Hopkins County. Hes a real gentleman, humble and a good listener, and hes a tireless promoter of sci/tech as a way to move the state forward economically and lift its peoples quality of life. Ill mention only a few of his accomplishments here.While a masters and doctoral student at Massachusetts Institute of Technology (MIT), he received six patents for high resolution display technology. Under his leadership as UK president, the university was awarded a 25-million-dollar grant from the National Science Foundation to improve math and science education in eastern Kentucky. Check out his initiatives; there are plenty more.

Dr. Phillip Sharp was born in Falmouth, the county seat of Pendleton County. Interestingly, he worked the family tobacco fields while growing up there. In 1993, he became the co-winner, with Richard Roberts, of the Nobel Prize in Physiology or Medicine in the field of RNA splicing. I previously profiled him in this KyForward column.

Isaac Chuang (Photo from MIT)

Awarded a degree in astronomy and astrophysics from Harvard, Louisville-born James Gilbert Baker (1914-2005) became a nationally known optical systems expert. He developed the Baker-Schmidt telescope and helped develop the Baker-Nunn camera, a series of twelve satellite tracking cameras. He also designed most of the lenses and cameras for Americas iconic U-2 spy plane.

Isaac Chuang is a native of Corbin and is recognized today as a pioneer in NMR quantum computing and has authored a primary reference book, along with Michael Neilsen, in the field of quantum information.

The president and chief executive officer of TWX Technologies, Rex Geveden, was born in western Kentucky, in Mayfield. Among many other high-profile positions, he formerly served as chief engineer at NASA.

Garrett A. Morgan (1877-1963), an African American, was born in Claysville, near Paris. His parents had been slaves. He became a well-known inventor, with his two most noted inventions being a three-position traffic signal and a smoke hood, which came before the gas mask. He pioneered some hair care products, too, and started a company with that line of products.

Garrett Morgon (Photo courtesy of Kentucky Monthly)

Besides Phillip Sharp, Kentucky had another winner of the Nobel Prize in Physiology or Medicine. Thomas Hunt Morgan (1866-1945), Lexington, won it in 1933 for his work in finding how the role that the chromosome plays in heredity. Interestingly, his first degree came in 1886 from the State College of Kentucky (later became UK), and he was valedictorian of the class. See https://www.bluegrasstrust.org/dr-thomas-hunt-morgan-house for a modern day tribute to Morgan.

A couple Kentuckians won the highest of rewards in the field of chemistry. William Lipscomb was born in Cleveland, Ohio, but his family moved to Lexington when he was a child. Lipscomb was the 1976 Nobel Prize in Chemistry recipient, specializing in nuclear magnetic resonance, theoretical chemistry, boron chemistry, and biochemistry. The other Kentuckian, Robert H. Grubbs, hails proudly from Marshall County (midway between Possum Trot and Calvert City.) His mother was a schoolteacher and his father a diesel mechanic. Grubbs was the co-recipient of the 2005 Nobel Prize in Chemistry for his work in olefin metathesis. Along with many other recognitions, in 2017 he was elected a Foreign Member of the Royal Society.

J. Richard Gott is a professor of astrophysical sciences and gravitational physics at Princeton University. Born in Louisville, he is known for his work in time travel and the Doomsday argument.

NASAs first Mars program director, G. Scott Hubbard, is a Lexington native. He received NASAs highest honor, the Distinguished Service Medal, and is the founder of the agencys Astrobiology Institute. Terrence W. Wilcutt, from Russellville and a Western Kentucky University graduate, is a U.S. Marine Corp officer and astronaut, a veteran of four Space Shuttle missions. He also has received a number of awards from NASA, including the Exceptional Service, Outstanding Leadership, and Distinguished Service medals.

The first industrial robot, named Unimate, was invented by George Devol (1912-2011), who was born in Louisville. He also created a company called United Cinephone and became known for his accomplishments as Grandfather of Robotics.

Though his accomplishments regarding the mobile radio transmitter-receiver were limited, Murray-born Nathan Stubblefield (1868-1928) proved a real player in inventing useful products. He patented a lamp lighter and electric battery, along with improvements in the invention of the telephone.

George M. Whitesides, another scientist from Louisville, is another nationally noted chemist. He is best known for his work in the areas of nuclear magnetic resonance spectroscopy, organometallic chemistry, molecular self-assembly, soft lithography, microfabrication, microfluidics, and nanotechnology. He attained the highest Hirsh index rating of all living chemists in 2011.

And whether one considers it for good or bad consequences, U.S. army officer John T. Thompson, from Newport, invented the Thompson submachine gun (often referred to as the Tommy Gun). I previously profiled him in this column Kentucky by Heart: Inventor of submachine gun was NKy native; finding strength in challenging times KyForward.com.

Science and technology in the Bluegrass?? Yep, we have game, and have for quite a few years.

Sources: Wikipedia; The Kentucky Encyclopedia

Originally posted here:

Kentucky by Heart: Many Kentuckians have made their mark in fields of science and technology - User-generated content

Q&A with Astrophysics Professor, Viktor Ambartsumian International Science Prize winner Adam Burrows – The Daily Princetonian

Adam Burrows is a professor of astrophysics at the University and has served on the Board of Trustees of the Aspen Center for Physics. In the past, he was the chair of the Board on Physics and Astronomy of the National Research Council and has worked on a number of committees for NASA.

Recently, Burrows was awarded the 2020 Viktor Ambartsumian International Science Prize for his seminal and pioneering contributions to the theories of brown dwarfs and exoplanets and for his leadership role in educating a generation of scientists at the frontiers of brown dwarf and exoplanet research, according to the Prize Committees press release. He sat down with The Daily Princetonian for a virtual interview, touching on his work on brown dwarfs, his career path, and the importance of teaching to excel in research.

The Daily Princetonian: Id like to start by saying congratulations for winning this prestigious prize. I understand that you won for your research on brown dwarfs and exoplanets. Could you walk me through what that work entails?

Adam Burrows: A number of decades ago, it was interesting, theoretically, to look at objects that were significantly smaller than regular stars. As you go down in mass, from one solar mass to half a solar mass, to one-third, etc., the luminosities go down significantly and the temperatures get lower and lower at the surface. When you get down to about one-twelfth of a solar mass, you get to the point where you can't derive enough thermonuclear burning in the star to balance the losses from the surface. So below that mass, you have what are called brown dwarfs. The brown dwarfs will have a little bit of thermonuclear life, but they won't be able to compensate for the losses from the surface. They're like dying embers plucked from a fire.

What I did with collaborators over the years was to calculate what these things would look like... Over the last many years, people have developed the technology necessary to characterize brown dwarfs we have discovered a few thousand of them but what we did early on was try to provide the theoretical context for understanding these objects. And thats what is being recognized.

You can also ask the question, What if you have an object that is much less massive than this transition mass, which, as I said, is one-twelfth of the solar mass, or around 70 Jupiter masses? If you go down to 60 or 40 masses, you have brown dwarfs, but if you extend it down to five, four, three, or just the mass of Jupiter, youre starting to talk about exoplanets. So, at the same time, we started putting together a theory about these objects, which is an extension of the work on brown dwarfs that straddles the realm between brown dwarfs and the planets we know in our solar system...

At around the same time, the first unimpeachable brown dwarf was discovered. [Michel] Mayor and [Didier] Queloz discovered 51 Pegasi b, the first exoplanet around a solar-like star, and this discovery garnered the Nobel Prize in Physics for them last year. At that time, we were the only theorists working on this general subject, and we taught a generation of theorists and observers about these objects. Collectively, the giant planet and brown dwarf work we did is the origin of this prize and the kudos that I quite gratifyingly received.

DP: What direction do you wish to take this work in the future?

AB: Important in the near future is what we can learn using the James Webb Space Telescope because it will be exquisitely sensitive to brown dwarf and exoplanet observation. There will also be another space-based satellite Ariel that the Europeans are going to launch towards the end of this coming decade. What were going to be able to understand at the lower temperatures of brown dwarf and exoplanet surfaces is cool molecular atmospheres similar to those of the local planets with which we are familiar...

I used to be the director of the Planets and Life certificate program at Princeton, which is astrobiology, and part of the subject is the connection with the origin of life. Theres a lot of study to try to understand the origin of life on Earth there was just the launch of the Perseverance probe to Mars, part of the tradition of Mars probes to search for signs of past life but it would also be nice to have other targets outside of the solar system, where we may be able to discern signatures of life. Thats a goal, and its been a goal of a good fraction of astronomy and planetary science for a long time.

DP: I know your many other research interests include impressive topics such as nuclear astrophysics and supernova theory, so whats another particularly memorable research experience or project from your career, and could you tell me a bit about it?

AB: Im still working a lot on supernova theory, and what were trying to do is to understand the mechanism of explosion. Supernovae are important agencies of change in the universe. Theyre the source of many of the heavy elements in nature. The iron in your hemoglobin, the calcium in your bones, the oxygen you breathe, and the fluorine in your toothpaste come from the massive stars that explode in supernovae.

The galaxy is constantly enriched by these heavy elements, and the solar system and the Sun are actually the products of this progressive enrichment. But the mechanism of these explosions has been shrouded in mystery because they happen in the deep interior of a star, which we dont have access to directly. By dint of nuclear physics, particle physics, and large supercomputers, weve recently been able to simulate in some detail the internal dynamics of this object that gives us a supernova.

DP: How did you get your start in astrophysics? What drew you to the field?

AB: I was interested in how things work and in physics, and what I liked about physics was its broad applicability. But I didnt want to major in just one aspect of physics. I wanted to range broadly, and you can do that in astrophysics. You learn a little bit about everything and bring it together its at the interface of many of the disciplines in physics and in the process, you learn how nature works, because it doesn't silo these disciplines, but combines them effortlessly.

DP: How do you think we should approach the search for life in space, with issues like both forward and backward contamination to consider? Also, some scientists suggest first coming up with an accurate definition of life before continuing our search in space. What are your thoughts on that?

AB: Its a much discussed topic: Youre talking about planetary protection and contamination, both backwards and forwards. People worry about that, but Im not as worried I think people have been pretty careful. But over time, with commercial space initiatives and with the multitude of countries that are getting involved, the solar system is going to be contaminated. So we better hurry up if were trying to understand the origin of life in the solar system.

Having said that, you also want to have a protocol for understanding what the atmosphere of a life-bearing planet looks like the so-called biosignature. Theres a lot of caveats there do you really have a general theory about what lifes products will be? Do you really have a general theory of the evolution of life in many different contexts? And there could be very many contexts that could give rise to self-replicating organic lifeforms that satisfy Darwinian evolution. Its something that requires thought in all directions, and I certainly wouldnt want to stop things just to contemplate how best to proceed. The most important thing is to start getting data, both in the solar system and beyond.

DP: How was your experience in working with NASA, with roles such as co-chair of the organizations Universe Subcommittee?

AB: You learn how the sausage is made, which is probably the most important thing, but you also get an appreciation for how hard a lot of these things are, and how good and professional of an organization NASA is. No organization is perfect, but its been quite successful. Its well-configured to answer many of the questions that many of us have about the universe...

DP: How does teaching inform your research, and vice versa?

AB: You really need to be connected to students, or you dont get the energy that they provide. You need to collaborate with students, not only because that gives you a means to get work done, but it also sparks ideas. Its only in the academic environment that youre challenged by new results coming in all the time, and the ivory tower isnt the best place to do real science mathematics, perhaps. You need to be engaged, and youre best engaged in an academic context, which involves students. And your involvement with students and their involvement with you is central to real progress in science.

Original post:

Q&A with Astrophysics Professor, Viktor Ambartsumian International Science Prize winner Adam Burrows - The Daily Princetonian

Astro Bob: Hubble helps solve the mystery of why Betelgeuse faded – Duluth News Tribune

Last winter Betelgeuse hit bottom. Although the star had been known for decades to vary in brightness, it reached a historic low in mid-February when it tumbled to magnitude 1.6, on par with its neighbor Bellatrix. Many of us watched the red supergiant star with great excitement, some even wondering if its behavior presaged a supernova explosion. Astronomers sought to explain its unprecedented dimming as possibly due to giant starspots darkening the stars surface or alternatively, light-absorbing dust clouds belched out by the monster star.

By March Betelgeuse had turned the corner and began to return to its former brilliance. Before it departed the evening sky in May it outshone nearby Aldebaran in Taurus. What happened?

When faintest in mid-February 2020, Betelgeuse equaled the star Bellatrix. It recovered in April and soon outshone Aldebaran. Magnitudes are shown in parentheses. (Bob King for the News Tribune)

Thanks to new Hubble Space Telescope observations a team of researchers now suggest that dust was the culprit. A large convective cell made of super-hot stellar gas called plasma welled up from Betelgeuses surface. A good way to picture this is to imagine rising air bubbles in a pot of boiling water. The plasma bubble ascended through the hot atmosphere and when it reached the colder, outer layers it cooled and formed dust. The resulting dust cloud blocked light from about a quarter of the stars surface, beginning in late 2019. By April the cloud had thinned or dissipated, and Betelgeuse returned to its normal brilliance.

With Hubble, we see the material as it left the stars visible surface and moved out through the atmosphere before the dust formed that caused the star appear to dim, said lead researcher Andrea Dupree, associate director of The Center for Astrophysics (Harvard & Smithsonian). We could see the effect of a dense, hot region in the southeast part of the star moving outward.

Like your unruly uncle or a husband whos a little too comfortable in a marriage Betelgeuse is a serial belcher. This infrared image from the Very Large Telescope (VLT) shows the immensity of the patchy dust clouds surrounding Betelgeuse in December 2019. The clouds form when the star sheds its material back into space. The black disk masks the star and its immediate surroundings so it can reveal the fainter dust plumes. The orange dot in the middle is an image of Betelgeuse itself. It looks tiny here, but if the star were swapped for our sun its outer surface would reach almost to Jupiter. In context, the dust clouds are enormous! (ESO / P. Kervella / M. Montargs et al. / Acknowledgement: Eric Pantin)

Astronomers kept track of the ejected material which was initially 2 to 4 times brighter than the stars normal brightness. Then a month later the southern hemisphere of Betelgeuse dimmed as the bright cloud cooled and darkened with dust. Specifically, astronomers looked at the element magnesium in the ejected gases and watched it travel from the surface to the outer atmosphere until it chilled to form dust.

Betelgeuse expands and contracts rhythmically, its surface rising and falling during each pulsation cycle. When the convective bubble erupted, observations show that the star was expanding at the same time. The team suspects that the pulsation may have given the hot gases an extra kick, hurrying them through the atmosphere and encouraging quick condensation.

Betelgeuse has a striking orange-red color and marks the shoulder of Orion the hunter. (Michael J. Boyle)

Every star is a time machine. Betelgeuse is about 650 light years away, so the dimming happened around the year 1370, not long after bubonic plague or Black Death (1346-1353) raged across Europe killing 50 million people. Vaccines were non-existent back then and medical care primitive. Lets hope science will soon get the current viral plague under control. One wonders what the world will be like 650 years from now. Will Betelgeuse still be around or will it have gone supernova and left a blank spot in Orions shoulder?

If youre getting up to see Orion at dawn, beam in on Betelgeuse and compare it to Bellatrix and Aldebaran. Guess what? The star is dimming again! This is very unusual since its normal bright-dim-bright cycle takes 420 days, and its only been a couple months since the last brightness peak in late May. Currently equal to Aldebaran, its anyones guess exactly what will happen next.

The mystery continues.

Read the original:

Astro Bob: Hubble helps solve the mystery of why Betelgeuse faded - Duluth News Tribune

The Alternative to Dark Matter May be General Relativity Itself – Astrobites

This guest post was written by Xing-Ye Zhu, a third-year undergraduate student at Nanjing University, for an assignment in the Astronomical Literature Reading and Writing class taught by Professor Zhi-Yu Zhang. Xing-Ye is currently working under the supervision of Professor Yi Xie on strong deflection gravitational lensing. When not doing science, he enjoys watching movies, plays, and Kunqu Opera. You can always find a Rubiks cube in his hands.

Title: Relativistic corrections to the rotation curves of disk galaxies

Authors: Alexandre Deur

First authors institution: Department of Physics, University of Virginia

Status: Open access on arXiv

For most astronomers, it is just common sense that dark matter accounts for approximately 85% of the matter in the universe. However, as long as the constituents of dark matter remain a mystery, some astronomers remain skeptical about our conventional understanding of dark matter. Recently, astronomer Alexandre Deur suggested that the theory of relativity itself may explain a phenomenon widely regarded as evidence for dark matter.

The theory of dark matter was proposed in the 1970s to explain the rotation curves of galaxies, which appeared inconsistent with the observed distribution of luminous matter (i.e. baryonic matter). The rotation curve of a disk galaxy, as shown in Figure 1, is the relation between the rotational velocity of stars in the galaxy and their radial distance from its centre. At larger radius, a typical spiral galaxy shows larger rotational velocity than the one predicted by the Newtonian gravitation of baryonic matter. The observed rotation curves typically show a plateau at large radius, therefore requiring more gravitation to keep the fast-moving stars from escaping the galaxy. This discrepancy is known as the missing mass problem. One possible explanation is the presence of additional mass which we cannot see. This missing mass is called dark matter. With the observed rotation curve, astronomers can easily calculate the missing mass required and therefore determine the distribution of dark matter.

Galaxy rotation curves are not the only evidence that exists for dark matter. For example, the Bullet Cluster is famous for being a smoking gun for dark matter. The Bullet Cluster consists of two merging galaxy clusters. The distribution of matter determined by X-ray imaging is very different to that inferred from gravitational lensing, suggesting the dark matter component has separated from the normal matter during the collision. See this website and this astrobite for further discussion. Dark matter also plays an important role in the widely accepted CDM model of cosmology.

For decades, astronomers have been searching for the essence of dark matter, both theoretically and experimentally. For example, astronomers have searched for WIMPs (Weakly Interacting Massive Particles) (read more in this astrobite and this one). It has also been hypothesised that dark matter may be made up of MACHOs (see this astrobite). However, the dark matter puzzle still remains unresolved, because it is challenging to completely verify or eliminate any of these theories (at least not yet). Some astronomers have suggested alternative theories. Is it possible that the missing mass is not actually mass, but an artefact arising from our mistaken understanding of the gravitation? After all, it is additional gravitation, rather than mass, that is required to explain the galaxy rotation curves.

It is not the first time physicists and astronomers have become skeptical about gravitation. One hundred years ago, the observation of Mercurys perihelion precession was initially interpreted as evidence of another planet inside the orbit of Mercury, but was later fully explained by a new theory of gravitation: general relativity. Today, astronomers are facing a similar problem is it something there, or is it just another correction to the theory of gravitation?

Modified Newtonian Dynamics, or MOND, for example, is the most discussed out of all the gravitation corrections to explain the missing mass problem (see this astrobite for further discussion of MOND vs. dark matter). It modifies the Newtonian gravitation law at low accelerations to enhance the effective gravitational attraction. Similarly, most of the other corrections require new descriptions of gravitation. But recently, as Deur proposes in this work, the effect of general relativity may account for the missing mass, without introducing any new corrections.

Generally, the predicted rotation of galaxies, as shown in Figure 1, is modelled by Newtonian dynamics. The rotation velocity is much smaller than the speed of light, especially at the outer part of the galaxy (typically , where is the velocity and is the speed of light). Therefore, it is believed that a non-relativistic treatment is reasonable. However, this assumption could be challenged due to the effect of field self-interaction in general relativity. This effect depends on the mass only, and is independent of the rotation velocity, thus making a difference regardless of how fast the stars move in the galaxy. Deur shows that field self-interaction, which reveals the non-linear nature of general relativity, is in fact not negligible in the missing mass problem.

To demonstrate this, Deur uses the gravitational lensing formalism. While light travels in straight lines in flat space, it can be deflected in the presence of a gravitational field. In exactly the same way, the gravitational field lines connecting two parts of the galaxy are distorted by the background field. That is to say, the gravitational field is deformed by the total galactic mass. With the field lines distorted, the strength of the gravitation consequently changes.

In addition to this, to reduce computation, Duer uses mean-field theory, an approximation technique widely employed in many fields (ha!) in physics. In this theory, the effect of all the other particles on any given individual particle is approximated by a single averaged effect, or the mean field, thus reducing a many-body problem to a one-body problem. Together with the gravitational lensing formalism, the self-interaction of the gravitational fields is computed. Figure 2 shows a demonstration of this effect it is clear that the self-interaction significantly distorts the gravitational field lines.

Duer demonstrates that field self-interaction increases gravitys strength compared to the Newtonian prediction. This effect will become noticeable in systems with sufficiently large mass. In Duers predicted rotation curve, shown in Figure 3, the observed plateau pattern is reproduced when field self-interaction is taken into consideration. Duer also computes the effective missing mass contribution derived from the comparison between the results of general relativity and Newtonian gravitation. This comparison leads to the prediction of a correlation between galactic dark mass and the vertical scale length of the disk galaxies and the prediction fits the observational data quite well.

In summary, Alexandre Deur proposes that the effect of field self-interaction needs to be included in the computation of rotation curve of the disk galaxy. Rather than merely taking the Newtonian gravitation into account, we need to consider the role general relativity plays in the physics of the galaxy. This consideration is able to partially explain the observed galaxy rotation curve, without modelling invisible dark matter or modifying the basic theory of gravitation.

In the debate about the existence of dark matter, Deur undoubtedly proposes another interesting possibility, yet more detailed investigation is needed to verify the significance of this effect. Maybe the relativistic effect is not enough to replace the missing mass completely, for there is other evidence for dark matter to explain. For disk galaxies at least, it is still important to know how much missing mass we have found. There is still a lot of work to be done before we can say that the puzzle of dark matter is resolved. However, we are getting closer all the time!

Continued here:

The Alternative to Dark Matter May be General Relativity Itself - Astrobites


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