Category Archives: Astronomy

Tendrils of galaxies up to hundreds of millions of light-years long may be the largest spinning objects in the universe, a new study finds.

Celestial bodies often spin, from planets to stars to galaxies. However, giant clusters of galaxies often spin very slowly, if at all, and so many researchers thought that is where spinning might end on cosmic scales, study co-author Noam Libeskind, a cosmologist at the Leibniz Institute for Astrophysics Potsdam in Germany, told Space.com.

But in the new research, Libeskind and his colleagues found that cosmic filaments, or gigantic tubes made of galaxies, apparently spin. "There are structures so vast that entire galaxies are just specks of dust," Libeskind said. "These huge filaments are much, much bigger than clusters."

Related: The best Hubble Space Telescope images of all time!

Previous research suggested that after the universe was born in the Big Bang about 13.8 billion years ago, much of the gas that makes up most of the known matter of the cosmos collapsed to form colossal sheets. These sheets then broke apart to form the filaments of a vast cosmic web.

Using data from the Sloan Digital Sky Survey, the scientists examined more than 17,000 filaments, analyzing the velocity at which the galaxies making up these giant tubes moved within each tendril. The researchers found that the way in which these galaxies moved suggested they were rotating around the central axis of each filament.

The fastest the researchers saw galaxies whirl around the hollow centers of these tendrils was about 223,700 mph (360,000 kph). The scientists noted they do not suggest that every single filament in the universe spins, but that spinning filaments do seem to exist.

The big question is, "Why do they spin?" Libeskind said. The Big Bang would not have endowed the universe with any primordial spin. As such, whatever caused these filaments to spin must have originated later in history as the structures formed, he said.

One possible explanation for this rotation is that as the powerful gravitational fields of these filaments pulled gas, dust and other material within them to collapse together, the resulting shearing forces might have spun up this material. Still, right now, "we're not really sure what can cause a torque on this scale," Libeskind said.

The scientists now seek to understand the origin of filament spin through computer simulations of how matter behaves on the largest cosmological sales. The researchers detailed their findings online June 14 in the journal Nature Astronomy.

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Astronomers discover largest known spinning structures in the universe - Space.com

Education | Profiles | Science | UW News blog

June 15, 2021

UW astronomer Emily Levesque delivers her course Great Heroes and Discoveries of Astronomy as part of The Great Courses, a popular online learning platform.The Teaching Company

If you look on Emily Levesques website, youll notice that one punctuation mark is prominent: the exclamation point. Classifying massive stars with machine learning! reads one blog post. Gravitational waves from Thorne-Zytkow objects! reads another.

My default state is exclamation point, said Levesque, an associate professor of astronomy at the University of Washington. When were talking about space and were talking about science, how could you not?

Now Levesque is bringing that enthusiasm to The Great Courses, an online learning platform offering classes to the general public on a range of topics, from playing guitar to decoding Egyptian hieroglyphics. Levesques course, Great Heroes and Discoveries of Astronomy, takes viewers on a tour of the biggest advancements in one of humanitys oldest sciences and the people behind them.

This course, which launched in February, came six months after Levesques popular science book on the history of observational astronomy, The Last Stargazers. The course consists of 24 lectures and covers the work of some scientists you may be familiar with, like Albert Einstein, Carl Sagan and Edwin Hubble, and others who might be new to you.

Those names include Henrietta Swann Leavitt. She was one of the Harvard computers, the team of women who processed astronomical data work made famous by the film Hidden Figures. Leavitts research on measuring the distances to stars laid the groundwork for Hubbles assertion that the universe is expanding. George Carruthers was an African American scientist who patented an ultraviolet camera and built the only telescope weve taken to the moon. Vera Rubin discovered dark matter; today an entire subfield of astrophysics is devoted to studying it. An enormous telescope in Chile is now named after her.

The course pokes at our idea of what a scientific hero is, Levesque said. Theres this stereotype that science is done by a white man alone in a room, coming up with an idea and then just spitting it out full formed into the universe.

This stereotype overlooks the collaborative nature of science, something Levesques course highlights. Breakthroughs can result from the efforts of a dozen scientists doing work that builds off each other over time, or from heroic efforts by teams of thousands. Levesque teaches a unit on the discovery of gravitational waves; the gravitational wave detector in Washington, part of the Laser Interferometer Gravitational-Wave Observatory, or LIGO, took thousands of people to build and takes thousands to maintain.

Levesque also broadens the definition of heroism to include acts like improving access to astronomy, making it more inclusive and bringing science literacy to the public.

One lecture tells the story of Frank Kameny, an astronomer in the U.S. Army Map Service. Months after he was hired in 1957, Kameny was fired when he refused to answer questions about his sexual orientation. He filed a lawsuit against the federal government, the first alleging discrimination based on sexual orientation in a U.S. court. Although it was unsuccessful, Kameny went on to become a leader in the fight for LGBTQ rights.

Its a really important time right now to remember that science is done by people, said Levesque. I dont think understanding science and understanding the human nature behind the discoveries we make has ever been more important. The human side of scientists cant be separated from the science that they do.

The human side of scientists not only affects their work, but it also shapes narratives around science. Stories we tell about scientific heroes and discoveries are often what makes science memorable. If the stories about people are interesting, then learning about the science will follow.

Levesque remembers, as a teen, reading the book A Man on the Moon: The Voyages of the Apollo Astronauts by Andrew Chaiken, about the early space program. She loved learning about the astronauts and the people in mission control. She was already a space geek, but reading about the fun they were having, identifying with them and seeing the creative problem-solving behind the science enabled her to picture what it would be like to work in astronomy.

Stories have the power to inspire or when the narrative is skewed or told from a singular point of view they can send a message about who does or doesnt belong. Thats why expanding the definition of a scientific hero beyond the stereotype is so important.

Levesque says her colleagues are a broad mix of people. They are ultramarathoners. They play in bands. They have a broad range of interests but have one thing in common: a love for space. More women are entering the field, but the low number of scientists from underrepresented groups like the Black and Latino communities shows there is still a ways to go when it comes to making astronomy more inclusive.

But if a broader range of stories are told, then more people will be able to envision themselves doing the work. And that will result in better science.

Its always worth reminding people when you talk about scientific heroism that you need heaps of people to do this work, Levesque said. Unique contributions can come from having a different perspective on a problem or other areas of expertise that a scientist can draw on. You need all sorts of talents and skill sets and enthusiastic folks who want to make science a part of their lives thats the ingredient, thats the way to do science.

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UW astronomer redefines the scientific hero as part of The Great Courses - UW News

As an astronomer whose research focuses on the imaging of extrasolar planets many light years away, Joe Carson spends a lot of time looking at distant celestial bodies. But his research and the imaging tools he and his team have created are grounded much closer to home. In fact, Carson credits the talent and skill produced right here at the College of Charleston for the development of medical imaging instrumentation that is now being used to look at human bodies on Earth.

Thats because his startup, Pensievision which primarily employs CofC alumni and students applies technologies from NASAs space telescopes to produce high-resolution 3D images using novel medical imaging instrumentation. The work includes their invention of the worlds first portable 3D colposcope to assist in early-stage detection of pre-cancer cervical lesions.

Over the past five years, everything that Pensievision has done has been enabled by students and alumni, who are the engine of the technologys development. Because of their work, we have been able to create this innovative and important device for doctors to use in any medical setting where imaging is used, says the associate professor of astronomy. My current projects long-term goal is to prevent cervical cancer deaths in some of the most underserved communities in the world, including those lacking medical infrastructure or even electricity.

Joe Carson and his startup, Pensievision, have created the worlds first portable 3D colposcope.

And, this spring, Carson was awarded a $400,000 National Institutes of Health (NIH) grant to make this a reality. Through the NIH Small Business Innovation Research (SBIR) program, Cancer Prevention, Diagnosis, and Treatment Technologies for Low-Resource Settings, the grant supports a 20-patient study of the 3D-imaging camera that Carson and his team created. The funding will allow Carson to travel to Kenya to meet with womens health leaders there and prepare for an intended follow-up patient study in sub-SaharanAfrica.

This grant will have far-reaching impacts and its all possible because of the CofC students and recent grads and all their hard work that has led up to this, says Carson. Theyve been creating new codes, designing and assembling devices, and applying software in novel ways.

The students and alumni even played a central role in creating the NIH grant application. And considering that the NIH review committee gave the proposal a perfect score they did a pretty great job!

A perfect score is unheard of Ive never seen one, Ive never heard of one, says Carson, explaining that usually a score of 40 indicates youve done really well, with 10 being perfect and 90 being poorest. When I saw the score of 10, I actually contacted the program administrator to see if there was an error. It just shows how innovative this technology is. Its a big jump from what we have now a huge paradigm shift. So, this shows that they see something really special and really valuable in this work.

As immense an impact that this technology might have across the world, Carson says its the impact that the work is having on the students and alumni that hes especially proud of.

It gives them experience with leadership and optical design lab testing, engineering, circuit boards and with FDA considerations, and that approval process, he says. Theyre not just learning the technology and the engineering, they get to learn about deploying these products. Theyre thinking about the consumer side of it: usability, scalability, aesthetics.

They also get to see the economics of it, Carson continues. They get to see how getting investor support is different than government support. They get to see how things all come together all the different angles, from design to diagnosis to make a difference in medical research from here to third world countries. These things are the future of medicine, so it puts them in an extremely strong position for imaging processing, artificial intelligence, data analyses and so on.

Junior astrophysics majorJenna Snead agrees that the independent research project she has done with Carson andPensievisionhas all sorts of applications including inthe astrophysics research that she plans to do after college.

While doing a medical imaging project seems way out in left field, astrophysics relies on a lot of the same imaging techniques, which will help me in any future astronomicalimaging projects, says Snead, who last semester won the School of Science and Mathematics Best of the Best Award, the Sigma Xi Best of the Best Award and the Department of Physics and Astronomy Best Poster Award for her research with Carson. Dr. Carson also often takes time to go into detail about how the concepts Im working with relate to my particular field, and to physics in general. Additionally, working with software and computer programming is indispensableto both grad school and any area of physics research, so getting familiar working with this projects code has been an amazing experience.

This summer Snead is working with circuits in an attempt to improve battery functionality and length of battery life, but her particular study of interest involves color analysis and how to best organize color channels to get the best image possible from the imaging wand.

This work is largely done on the software side. While this seems like a small project, it is important that we can get a clear image so that the future clinicians using it can diagnose as accurately as possible, she says. The coolest thing Ive learned inmy research so far is definitely how we actually process light and create images. Everything we perceive requires a different focal lengthwhich,when done manually (as we are doing with our 3D imaging),requires long lines of code. However, our brain does it automatically, every second of the day. Its just crazy when we think about how capable our brains are of processing the world around us.

Its these kindsof connections that make Carson so excited about what the College can inspire in its students and how valuable that is to the future workforce.

The College produces smart, creative, hardworking innovators. It provides a really good educational background and its graduates are bringing that education out into the world, he says. The students and graduates of the College really are the lifeline of Pensievision our number one resource.

In addition to producing a smart and skilled staff for Pensievision, the College has supported Pensievision through partnerships and grant applications, too.

Pensievision did not sprout up by itself it took a lot of support. And I cannot emphasize enough CofCs role in partnering to save lives and to create high paying jobs in the Lowcountry. Forming those partnerships has been invaluable, says Carson, adding that in recent years Pensievision has been among the top employers of students graduating from the Colleges Department of Physics and Astronomy. And as CofCs engineering program gets up and running in the next few years, I think that this partnership will continue to expand.

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Astronomy Professor Develops Innovative Medical Imaging Device - The College Today

Astronomers have performed photometric and spectroscopic observations of B2 1420+32, a blazar with a collection of changing-look features.

Sloan Digital Sky Survey archival image from March 2004 (left) and the image from the observation campaign of B2 1420+32 taken by Mishra et al. in January 2020 using ASAS-SN (right); the blazars brightness increased by a factor of 100. Image credit: SDSS / Mishra et al., doi: 10.3847/1538-4357/abf63d.

Blazars are powerful active galactic nuclei (AGN) with relativistic jets pointing toward the observer.

Their jets span distances on the million light-year scales and are known to impact the evolution of galaxies and galaxy clusters in which they reside via the radiation.

These features make blazars ideal environments in which to study the physics of jets and their role in galaxy evolution.

Blazars are a unique kind of AGN with very powerful jets, said lead author Hora Mishra, a Ph.D. student in the Homer L. Dodge Department of Physics and Astronomy at the University of Oklahoma.

Jets are a radio mode of feedback and because of their scales, they penetrate the galaxy into their large-scale environment.

The origin of these jets and processes driving the radiation are not well-known. Thus, studying blazars allows us to understand these jets better and how they are connected to other components of the AGN, like the accretion disk.

These jets can heat up and displace gas in their environment affecting, for example, the star formation in the galaxy.

In the research, Mishra and her colleagues investigated the evolution of B2 1420+32, a blazar located 6.3 billion light-years away in the constellation of Botes.

At the end of 2017, this blazar exhibited a huge optical flare, a phenomenon captured by the All Sky Automated Survey for SuperNovae (ASAS-SN) telescope network.

We followed this up by observing the evolution of its spectrum and light curve over the next two years and also retrieved archival data available for this object, Mishra said.

The campaign, with data spanning over a decade, has yielded some most exciting results.

We see dramatic variability in the spectrum and multiple transformations between the two blazar sub-classes for the first time for a blazar, thus giving it the name changing-look blazar.

The astronomers concluded that this behavior is caused by the dramatic continuum flux changes, which confirm a long-proposed theory that separates blazars into two major categories.

In addition, we see several very large multiband flares in the optical and gamma-ray bands on different timescales and new spectral features, Mishra said.

Such extreme variability and the spectral features demand dedicated searches for more such blazars, which will allow us to utilize the dramatic spectral changes observed to reveal AGN/jet physics, including how dust particles around supermassive black holes are destructed by the tremendous radiation from the central engine and how energy from a relativistic jet is transferred into the dust clouds, providing a new channel linking the evolution of the supermassive black hole with its host galaxy.

We are very excited by the results of discovering a changing-look blazar that transforms itself not once, but three times, between its two sub-classes, from the dramatic changes in its continuum emission.

In addition, we see new spectral features and optical variability that is unprecedented. These results open the door to more such studies of highly variable blazars and their importance in understanding AGN physics.

It is really interesting to see the emergence of a forest of iron emission lines, suggesting that nearby dust particles were evaporated by the strong radiation from the jet and released free iron ions into the emitting clouds, a phenomenon predicted by theoretical models and confirmed in this blazar outburst, said Dr. Xinyu, also from the Homer L. Dodge Department of Physics and Astronomy at the University of Oklahoma.

The study was published in the Astrophysical Journal.

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Hora D. Mishra et al. 2021. The Changing-look Blazar B2 1420+32. ApJ 913, 146; doi: 10.3847/1538-4357/abf63d

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'Changing-Look' Blazar Spotted 6.3 Billion Light-Years Away | Astronomy - Sci-News.com

It was something not from the Earth, U.S. Navy Cmdr. David Fravor, commanding officer of a squadron of F/A-18 Hornet fighter planes, said in an interview with the Washington Post about the fast-moving, Tic Tac-shaped UFO he sighted during a 2004 training mission over the California coast. The object moved unlike any aircraft he was aware of and seemed to defy nearby radar operators efforts to track it.

Fravors account of the incident remained classified for 13 years until the Department of Defense announced the formation of the Unidentified Aerial Phenomena Task Force in 2017 and charged it with the job of cataloging and analyzing sightings of strange aerial objects that could potentially represent a threat to U.S. national security.

Late in 2019, lawmakers asked the secretary of defense and director of national intelligence to submit a report on what the task force has learned about the objects we know as UFOs, and an unclassified version of that report is scheduled to be released later this month.

Government officials have already confirmed that the task force has found no evidence of alien spacecraft, but University of Virginia astronomer Kelsey Johnson, who is president-elect of the American Astronomical Society and also a former member of the National Science Foundations Astronomy and Astrophysics Advisory Committee, spoke with UVA Today about what the report might contain and what it might mean for those of us who are eager to catch a glimpse of extraterrestrial life.

Q. What do you think the governments report on UFO activity is most likely going to tell us?

A. I think the report is likely to confirm that there have been sightings of objects in the sky that are currently unexplained. The catch is that just because something is unidentified does not mean that it was extraterrestrial life visiting Earth. If you are really bad at identifying things, then anything in the sky could technically be a UFO.

Taking the step to infer that the object is extraterrestrial in origin requires evidence and in science we have a saying that extraordinary claims require extraordinary evidence. Finding evidence for extraterrestrial life would pretty much peg the meter on extraordinary.

That being said, regardless of the origin of objects in UFO sightings, I think these occurrences can be important to study and understand. Objects that have been observed by reliable witnesses and recorded to behave in unexplained ways absolutely merit legitimate scientific effort. Even if the explanation isnt aliens, we might gain new insight into a natural phenomenon or better understand threats to national security. I find it really unfortunate that so much stigma has become attached to this topic among both scientists and government officials. Yes, be skeptical and require evidence, but also be open-minded to explanations you cannot rule out.

This stigma has actually spun off a new term with less baggage: Unidentified Aerial Phenomena, or UAP.

Q. What kinds of phenomena are most likely reported as UFOs or UAP?

A. This depends on who is doing the reporting! For the general public, one of the underlying issues is that many people simply dont spend a lot of time outside looking at the sky, so folks are not so familiar with objects that are totally normal. As a result, Venus, Mars and even the moon are frequently reported as UFOs. But there are also a number of less-common, but still 100% explainable, atmospheric phenomena that can appear pretty strange if you dont know about them everything from sun dogs caused by ice crystals in the atmosphere to really funky clouds. Lenticular clouds can do an especially great job mimicking Hollywood-style flying saucers.

Things get much harder to explain when there appear to be changes in motion that defy known modern technology. This is what has raised some eyebrows with the recent reports by the military. I am reminded of the god of the gaps fallacy, which is to say that just because we dont understand something doesnt mean the explanation is supernatural or alien.

Q. What might make some of these phenomena appear to be something other than what they are?

A. Human perception is fraught with issues and is extremely unreliable, and the need to be skeptical of personal accounts is amplified when something isnt reproducible. We are also incredibly bad at gauging distances. If we dont really know how far away something is, changes in motion are easily misinterpreted by our brains. For these reasons and others, it is essential to have actual data and measurements to test against different hypotheses.

Q. Are there good reasons for using federal or military funding for further research into these sightings?

A. I think it is always worthwhile to study things we dont understand. That is how we make progress toward understanding the universe we live in. Truly unexplained phenomena with associated data should not be sitting on a shelf these could reveal something very cool about the natural world or a novel technology that could be beneficial or threatening.

Q. How could science benefit from a renewed interest in extraterrestrial visitors?

A. Science is all about curiosity, and thinking about extraterrestrial life is rich ground for asking a huge range of questions. I absolutely love talking about and teaching these questions as a hook for inquiry what forms might extraterrestrial life take? What environments might they need to live? How would they communicate? Would they even want to communicate? Considering these questions also gives us insight into ourselves and our own place in the universe.

Q. What is the likelihood that aliens have, in fact, visited Earth?

A. The likelihood that extraterrestrial life has visited Earth depends on a number of assumptions. Im not going to give a specific likelihood, but I will say that with some basic assumptions, one could infer that the universe ought to be teeming with life.

Now whether extraterrestrial life is commonly able to survive and evolve into something more than a simple organism let alone develop technology and travel across the galaxy is the crux of the matter. Answering these questions goes beyond astrophysics and astrobiology into fields that dont exist yet like astrosociology and astropsychology.

Q. What kind of proof would scientists in those fields need to be sure?

A. To prove extraterrestrial life had visited Earth would require us being able to unequivocally rule out terrestrial origins, and that is tough. To prove something in the scientific sense, the phenomenon generally has to be repeatable so that hypotheses can be tested. With only fleeting and unpredictable sightings, it is virtually impossible to test hypotheses to verify or dismiss them. This leaves us wanting for real, tangible, physical artifacts that can be examined and tested by a range of scientists.

The late Arthur C. Clarke had three adages known as Clarkes Three Laws the first of which was, When a distinguished but elderly scientist states that something is possible, he [sic] is almost certainly right. When he [sic] states that something is impossible, he [sic] is very probably wrong. We would all do well to use the word impossible with caution.

Q. How would you feel if extraterrestrial life were discovered?

A. I would be elated. If there is no other sentient life in the galaxy, that is a huge warning sign for humans and our potential for long-term survival. And how sad it would be for this enormous and grand universe to have so few to bear witness. I also think that finding other sentient life would bring about a beautiful renaissance of human thought and knowledge. I have to believe that our worldviews would change for the better if we had a deeper understanding that we are all truly on this tiny little planet together.

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Astronomer Kelsey Johnson Reflects on the Science Behind the Search for UFOs - University of Virginia

An international team of astronomers from the United States and the United Kingdom has made the discovery of a giant, almost symmetrical arc of galaxies by looking at absorption lines in the spectra towards quasars from the Sloan Digital Sky Survey (SDSS).

The Giant Arc: the gray contours represent the Mg II absorbers, which indicate the distribution of galaxies and galaxy clusters; the blue dots represent the background quasars; the Giant Arc is centered on this figure spanning -600 to +400 Mpc on the x-axis. Image credit: Lopez et al.

The newly-discovered arc of galaxies is located more than 9.2 billion light-years away in the constellation of Botes.

Named as the Giant Arc, it spans approximately 3.3 billion light-years in length and 330 million light-years in width.

The structure is twice the size of the striking Sloan Great Wall of galaxies and clusters that is seen in the nearby Universe.

Its discovery adds to an accumulating set of cautious challenges to the Cosmological Principle.

The growing number of large-scale structures over the size limit of what is considered theoretically viable is becoming harder to ignore, said Alexia Lopez, a Ph.D. student in the Jeremiah Horrocks Institute at the University of Central Lancashire.

According to cosmologists, the current theoretical limit is calculated to be 1.2 billion light-years, which makes the Giant Arc almost three times larger.

Can the Standard Model of cosmology account for these huge structures in the Universe as just rare flukes, or is there more to it than that?

Lopez and colleagues made the discovery by observing the intervening magnesium (Mg) II absorption systems backlit by quasars, which are remote super-luminous galaxies that emit extraordinary amounts of energy and light.

A quasar acts like a giant lamp shining a spotlight through other galaxies, with the light eventually reaching us here on Earth, Lopez said.

We can use telescopes to measure the spectra of these quasars, which essentially tells us the journey that the quasar light has been through, and in particular where the light has been absorbed.

We can locate where the quasar light has passed through galaxies by a signature Mg II doublet feature, which is a distinctive pair of absorption lines in the spectra.

From this easily identified absorption fingerprint, we can map low luminosity matter that would usually go unseen due to its faint light emitted in comparison to the quasars.

When viewed on such a large scale, we expect to see a statistically smooth distribution of matter across the Universe, based on the Cosmological Principle introduced by Einstein to make the maths easier, that the Universe is isotropic and homogeneous.

It means that the night sky, when viewed on a sufficiently large scale, should look the same, regardless of the observers locations or the directions in which they are looking.

The Giant Arc we are seeing certainly raises more questions than answers as it may expand the notion of sufficiently large. The key question is, what do we consider to be sufficiently large?

We are seeing the Giant Arc now, but in reality, the data were looking at show the Universe as it was half its lifetime ago because the light has been en route, traveling towards, us for billions of years. It was so long ago that the Universe at the time was about 1.8 times smaller than it is now.

The astronomers presented the results this month at the 238th virtual meeting of the American Astronomical Society (AAS).

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A.M. Lopez et al. 2021. A Giant Arc on the Sky. AAS 238, abstract # 111.01

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3.3-Billion-Light-Year-Long Arc of Galaxies Discovered | Astronomy - Sci-News.com

Texas A&M University astronomer Nick Suntzeff has been involved with space research for 30 years and spent 20 years in Chile, where he helped co-discover dark matter. Below, he offers his thoughts about UFOs and whether or not we are alone in the universe.

The New York Times and CNN reported a government report on "UFOs" does not provide evidence of aliens, but also doesn't rule the possibility out. USA TODAY

Q: What can we expect from the governments official UFO report?

A: I have no idea what the report will say, but I doubt they have any evidence where a UAP (Unidentified Aerial Phenomenon, previously called a UFO) is clearly resolved. For starters, have you ever noticed that UAP images and videos are usually out of focus?

In the recent videos that are now getting a lot of attention called FLIR1, Gimbal, Triangle, and GoFast, for instance, lets consider the triangular UFO. In the video you can also see other objects that are triangles. Are these sister UFOs? No. What this means is that the camera was out of focus and the camera pupil (shutter) was triangular. One person has measured the positions of the faint triangles (and one bright one) and shown that they are at the positions of the stars near the constellation Taurus and the planet Jupiter. Also, this UFO blinks in the same way a commercial aircraft does. It was taken off the coast of Los Angeles where there are lots of air traffic. It is an out-of-focus video taken with an infrared camera.

UFOs, or unidentified flying objects, have stirred our imagination for generations. Sightings of these alleged interstellar visitors to Earth have been chronicled throughout history. However, the mania for UFOs shifted into hyperdrive in 1947, when flying saucer enthusiasts believed the remains of an otherworldly spacecraft, and even the corpse of an alien, were discovered in Roswell, New Mexico.(Photo: ursatii / Getty Images)

This is one example of an explanation that fits the data. Now, why did the Navy not provide this explanation? They should have asked an astronomer before releasing the video because they could have quickly shown that this an out of focus image.

Q: So does that mean the UFOs are not real?

A: Well, you can often debunk one story, but you will then get another story and someone will say, okay, but explain this one.

In one video, a pilot said the UFO resembled a large Tic Tac mint and that it was defying the laws of physics over the ocean and moving fast. The problem here is that we dont know how far away it was. If it was high above the ocean, then the apparent motion is likely due to the airplane and not the object.

This is called parallax. You can often find answers like this, and so on.

So I am not optimistic that we will be shown extraordinary evidence where there is no natural explanation for what is seen.

Q: So you are saying that you can rule out most UFO sightings as something else and not a UFO?

A:There are often simple, but boring answers. For example, the most common UFO is the planet Venus. Once I got a phone call from an excited person who was telling me they can see a UFO right now. It is moving back and forth, and sometimes it suddenly comes closer and then moves away. I asked them if they could still see it. Yes! So I drove down to the parking lot and there was a group of people bunched together pointing up to the sky. I went over there and asked them to show me where it is. I look up there, and it is Venus. I tell then it is Venus. I look at it and it is not moving. It was twinkling a bit but otherwise, nothing unusual. As we looked, they admitted it was not moving, but I was assured that it was before I got there.

Q: Many people are convinced that these UFOs are visitors from another planet, that they have been monitoring the Earth for decades and they are real. If true, it would be perhaps the biggest story of all time. Is it possible?

A:I cant rule out we have visitors from other planets. But we need clear evidence. We need a clear photo for instance. So far, we do not have such evidence.

Note that many reports say that the UFO object was a certain size and moving at a certain speed. Now, if you dont know what the object is, you cant know how far away it is, or how big it is. Anyone who says they know the size (unless it landed and left a mark) is, well, not understanding simple optics. So once again, we need clearer proof. I have seen lots of weird things in the sky very weird things but I can always explain them.

As for intelligent life in a way it is a strange question. As the great physicist Enrico Fermi was claimed to have said, Well, where are they? That is, if there is intelligent life, why dont we see it with our telescopes, or see evidence here on Earth of visitations? Astronomers are always looking for life elsewhere in the universe.

Congress-sanctioned UFO report to be released in June 2021.(Photo: U.S. NAVY)

Q: Any shred of truth to the long-held rumors that the government has been hiding pieces of crashed UFOs and perhaps even bodies?

A: If they do, this is the best kept secret ever. Our government is not great at keeping secrets, and this one would be a doozy. No, I dont believe there is any physical evidence. I dont think intelligent civilizations could travel the thousands of light years to the earth, and then crash their spacecraft. If they can travel that distance, I seriously doubt they would be this careless.

Q: It seems like the scientific community has always been more than a little reluctant to talk about UFOs. Why is that?

A: We are not reluctant to talk about it. There are a number of astronomers actively looking for signs of intelligent life out there. It is a real field in astronomy. The problem is that one cannot get government funding to study UFOs. So those astronomers look to the private sector to do the studies. A very close friend of mine, now retired, built his own observatory and is searching for intelligent signals. He got this funded by some rich person in Silicon Valley. If there were sources of steady funding, I am sure a lot of young astronomers would take a job searching for intelligent life.

Q: Any other thoughts you may have about UFOs?

A: . This is thought experiment. We are not too far maybe 100 years or so from building mini-satellites, accelerating them up to 10% the speed of light using lasers, and sending them off to nearby stars. We could make billions of them after all, we have made billions of cell phones so far. With laser acceleration and light-weight satellites (10 grams or so), we could launch these to billions of stars. The satellite could have a radio transmitter beeping the first 10 Fibonacci numbers (numbers used to create a mathematical sequence) showing it must be artificial.

If I can imagine this future technology which is not far from what we have today, the question is, why is there no satellite from another civilization that has passed this way, and beeped at us?

The only fact we are certain of is that so far -- and we are looking hard -- it is silent out there.

Texas A&M University astronomer Nick Suntzeff has been involved with space research for 30 years and spent 20 years in Chile, where he helped co-discover dark matter.(Photo: Contributed photo)

By Keith Randall, Texas A&M University Division of Marketing & Communications

Read or Share this story: https://www.timesrecordnews.com/story/news/2021/06/17/texas-a-m-astronomer-weighs-upcoming-ufo-report/7738172002/

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Texas A&M astronomer weighs in on upcoming UFO report - Times Record News

For over five thousand years, India has been home to one of the fascinating intellectual endeavours that humankind has ever recorded. India, one of the oldest civilizations in the world, has a strong tradition of science and technology.Ancient India was a land of sages and seers as well as a land of scholars and scientists.

From the ancient Vedic ages till today, the Indians have exhibited unmatchable deep understanding and mastery over knowledge across the spectrum. The ancient Indians have left us a great treasure of knowledge, and the rational interpretation of these ideas, which has become the basis of knowledge discovery across the civilization for several ages now. From astronomy to metallurgy, mathematics to medicine, the contribution of Indians to the global knowledge discovery is enormous.

The origins of the Indian scientific endeavours can be traced to the Vedic period, over three thousand years ago. The Indian scientists have made several discoveries, becoming one of the firsts to shed light on several scientific ideas much earlier than the inception of the very same ideas in the west.In addition to discovering and recording scientific phenomenons, the Indian sages had also absorbed the scientific methods of the other culture-areas in all true spirit, thus displaying a real scientific attitude.

In fact, what interesting is, such an effort by the ancient Indians has been characterised by prolonged observations, especially with the naked eye and simple tools, at times aided by techniques that we seem to discard as crude and primitive.

A fact of great significance is that Indians produced a vast literature on different aspects of astronomy, cosmology, numerology, measures of time, development of observatories, instruments etc. The ancient Indians were also the first to study the planetary motions, design calendars, study time and the inter-disciplinary nature of many of these above aspects.

In a book titled Indian Astronomy: A Source-Book, the authors BV Subbarayappa and KV Sharma, have recorded more than 3,000 such observations and discoveries by Indian scientists, astronomers and mathematicians over thousands of years. The book intends to provide a general insight into the scientific discoveries in the field of astronomy, numerology, a measure of times and several other aspects that were accomplished in ancient India.

About 3000 verses, written by the likes of the greatest Indian astronomers and thinkers like Aryabhata, Bhaskarcharya, Brahmagupta etc have been extracted from many original sources, mainly in Sanskrit, and presented with their translations in English and notes by the authors.

Here are few of them that shed light into understanding how ancient India was the cradle for one of worlds greatest scientific discoveries.

These passages in Sanskrit brings out the authenticity of the basic characteristics of Indian astronomy as it outlines the expertise expected of an astronomer in ancient times. The below verse outlines how there was utmost importance to accuracy in ancient ages and how one had to adopt the intricate methodologies to become an astronomer. More significantly, the ancient texts gave importance to observation and mathematically developed documentation to ensure that Indian astronomers did not indulge in speculation but on empirical data.

Here is a verse that sets eligibility standards for individual practising astronomy. The ancient verses written during the Vedic ages set rules to be followed by a person before the performance of sacrifices.

The Vedas state that a certain sequence of actions should be followed at appropriate times before performing sacrifices. Hence, he who knows astronomy, which is the science specifying time, knows the sacrifices and, so, is a Vedist, reads the verse written in Rig Veda.

In his extraordinary encyclopaedia Brihat Samhita, the ancient Hindu astrologer, astronomer and polymath Varahamihira, has accounted for the detailed qualification one has to possess to become an astronomer. Varahamihira, who himself was an accomplished astronomer during the 6th century BC, was one of the first in the world to study and detail about the Sun in his treatise Surya Siddhanta.

The below verse details the conditions for an individual to be qualified as an astronomer:

The translation reads:

Among the astronomical calculations, the astronomer should be conversant with the various sub-division of time such as the yuga, year, solstice, season, month, fortnight, day and night, Yama (a period of an hour and a half), muhurta (forty-eight minutes or two ghatis), Nadi (equal to 24 minutes), prana (time required for one inhalation), truti (a small unit of time) and its further subdivisions, as well as with the ecliptic (or with geometry) that are treated of in the five Siddhantas entitled Paulisa, Romaka, Vasistha, Saura and Paitamaha. (4)

He should also be thoroughly acquainted with the reasons for the existence of the four measurement systems of the time, viz. Saura or the solar system, Savana, or the terrestrial time, i.e. the time intervening between the first rising of any given planet or star and its next rising, Nakshatra or sidereal, and Chandra or lunar, as well as for the occurrence of intercalary months and increasing and decreasing lunar days. (5)

He should also be well-versed with the calculation of the beginning and ending times of the cycle of sixty years, a yuga (a five-year period), a year, a month, a day, a horn (hour), as well as of their respective lords. (6)

He should also be capable of explaining, using arguments, the similarities and dissimilarities, and the appropriateness or otherwise of the different systems of measurement of time according to the solar and allied systems. (7)

Despite differences of opinion among the Siddhantas regarding the expiry or ending time of an Ayana (solstice), he should be capable of reconciling them by showing the agreement between correct calculation and what has been actually observed in the circle drawn on the ground using the shadow of the gnomon as well as water-instruments. (8)

He should also be well acquainted with the causes that are responsible for the different kinds of motions of the planets headed by the Sun, viz. fast, slow, southerly, northerly, towards perigee and apogee. (9)

He must be able to forecast, by calculation, the times of commencement and ending, direction, magnitude, duration, intensity and colour at the eclipses of the Sun and the Moon, as well as the conjunctions of the Moon with the five Taragrahas or non-luminous planets and the planetary conjunctions. (10)

He should also be an expert in determining accurately for each planet, its motion in yojanas, its orbit, other allied dimensions etc., all in terms of yojanas. (11)

He must be thoroughly acquainted with the Earths rotation (on its own axis around the Sun) and its revolution along the circle of constellations, its shape and such other details, the latitude of a place and its complement, the difference in the lengths of the day and night (lit. diameter of the day-circle), the carakhandas of a place, rising periods of the different signs of the zodiac at a given place, the methods of converting the length of shadow into time (in ghatis) and time into the length of the shadow and such other things, as well as those to find out the exact time in ghatis that has elapsed since sunrise or sunset at any required time from the position of the Sun or from the Ascendant, as the case may be. (12)

Even thousands of years before the Western astronomers discovered the shape of the Earth, Indian astronomers had accurately predicted Earths shape as spherical.

During Varahamihiras period, the development of astrological and astronomical sciences reached a pinnacle. In his book Paulisa Siddhanta, Varahamihira gives an exact description of not only the share of the earth, i.e., spherical but also provides its topographical study in detail.

The verse in Paulisa Siddhanta accounts, Earth is spherical and constituted of the five elements, which stands poised in the region of space as if it is an iron ball held in position in a cage of magnets. (1)

The whole earth surface is spotted by trees, mountains, cities, rivers, oceans, etc. The Meru mountain (forming the North pole) is the abode of the devas (gods). The Asuras (demons) are down below (i.e. at the South pole). (2)

Just as the reflection of the objects on the bund of a water source is upside down, so the asuras are (with respect to the devas.) The asuras, too, consider the devas to be upside down. (3)

Just as the flame of the fire, observed by men here, flares upwards, and anything is thrown up falls down towards the earth, the same upward flaring of the flame and the downward falling of a heavy object is experienced by the asuras (at the antipodal region). (4)

Below is another documentation by Varahamihira describing Earth and its close correspondence with Panchabhutas.

This sphere of Earth, made of akasa, air, fire, water and clay and thus having all the properties of the five elements, surrounded by the orbits (of the Moon, etc.), and extending up to the sphere of stars, remains in (the centre of) space. (1)

Just as a ball of iron, when placed amidst pieces of magnets, remains suspended in space, in the same manner, this globe of Earth remains in space unsupported, while itself remaining the abode of all. (2)

The third verse says Yamakoti is to the east of Lanka (which is in the middle of the Earth), and Romaka (Rome) is to the west. Siddhapura is beneath Lanka (just opposite); the Meru (mountains) is to the north, and the abode of the demons is to the south. (3)

These (four cities) are on islands. Meru is on the land, and the abode of the demons (in the south) is surrounded by water. These six places are believed to be situated transversely at a distance of one-fourth of the Earths circumference (that is 90), each from the next one. (4)

Those who are at a distance of half the Earths circumference from each other are antipodes, just as a man (standing on the bank of a river) and his reflection in the water. The sky is above all. This (globe of Earth) is beneath it. The inhabitants are on the surface of the Earth. (5)

Kamalakara, anIndianastronomerandmathematician,who lived in Varanasi in the 17th century AD, gave the first detailed account of the causes of earthquake within Earths crust. However, the European geologists took another century to publish a basic understanding of Earths interiors and the phenomenon of Earthquakes.

In his book Siddhntatattvaviveka, Kamalakara has stated that the Earths crust is hard and rocky. Explaining the process of the earthquake, he writes, a fissure occurs due to lack of strength, gases emerge forcibly, causing the Earth to quake when there would also be constant terrific noise.

Similarly, Lalla, anIndianmathematician,astronomer, andastrologer, had discovered in the 8th century AD that the Earth travelled from west to east and if anyone viewed it from the north pole star Polaris,Earthturns left, i.e., counterclockwise.

The Indian astronomers made accurate discoveries on earths rotation and direction of rotation; centuries before, European astronomers came up with such predictions explaining concepts of Earths rotation.

Lallass documentation on Earths rotation on its axis and the direction of its rotation:

The translation of Lallas work reads: The celestial sphere, at the Earths equator, is constantly carried towards the west by the Pravaha wind. To the gods (at the north pole), it appears to move (from the left) to the right and the demons (at the south pole from the right) to the left. (3).

Chaturveda Prithudaka Swami, another astronomer, known for his exemplary work on mathematical equations, explained that it is only the Earth that is regularly rotating once a day, and the sphere of the stars is fixed, causing the rising and setting of the stars and the planets.

In his book Commentaries onBrahmasphuasiddhanta, Prithudaka Swami explain the causes behind the phenomenon of days and nights.

The translation of one of his works reads: The Earths rotation had been accepted by Aryabhata also, vide his words, The Earth rotates through (an angle of) one second per one prana (of time). On account of (possible) adverse criticism by people, Bhaskara I and others explained the verse to give it a different meaning.

Aryabhata, arguably the worlds oldest astronomer, had explained the rotation of Earth on its own axis. The above work of Aryabhata is mentioned in his masterpiece Aryabhatiyam, which translated into, Rotation of the Earth also has been accepted by Acarya (Aryabhata). Note that there is a variant reading as The Earth rotates through (an angle of) one second per one prana (of time).

In his book, Aryabhata explains, Just as a man in a boat moving forward sees the stationary objects (on either side of the river) as moving backwards, so are the stationary stars seen by people at Lanka (on the equator), as moving exactly towards the west. (9)

(It so appears as if) the entire structure of the asterisms, together with the planets, moved exactly towards the west of Lanka, being constantly driven by the pro-vector wind to cause their rising and setting. (10)

The earlier texts also had reference to the direction of the earths rotation. Makkibhatta, too has discovered that the Earth rotates on its own axis from west to east.

Rig Vedic verses, written more than 5,000 ago, had estimated the dimensions of Earth. Here is a Rig Vedic verse that mentions Mother Earth and its dimensions. It is by far the oldest document to speak, even though it does not explain details about the dimensions and size of the earth.

The translation of the Rigvedic verse translated into: Oh (God) Indra, were this Earth to magnify itself tenfold (i.e., infinitely) and men who live on it multiplied day by day, then and then alone will the lauded might and glory of yours be as vast as the heavens.

In his seminal work, Varahamihira builds on assumptions of Rigvedic times and accurately estimates the circumference of the earth as 3200 yojanas. Furthermore, each Yojana is estimated to be 12-15 km, which translates into nearly 38,000 km to 45,000 km, which is almost accurate to the current estimates.

Earths circumferenceis the distance aroundEarth and it is Measured around the Equator, it is 40,075.017 km.

When situated on the equator, the Sun is visible from pole to pole at all latitudes, making the day and night equal). The middle of the Earth (the North pole is meant here) is north of Ujjain by 586 2/3 yojanas. It is north of Lanka by 800 yojanas.

Similarly, in his book Khandakhadyaka, Brahmagupta had also estimated the circumference of the Earth. The above documentation in his book suggests that he had mathematically derived an accurate measurement of Earths circumference.

The translation of Brahmaguptas work reads: Multiply 5000 by thejja of the colatitude of the place and divide the product by the trijyd. The result is the correct circumference of the Earth at that place. (6a)

Deva, another ancient astronomer, too had come up with an accurate measurement of the Earths circumference. In addition to it, Deva had also calculated the distance between Ujjain (Madhya Pradesh) and Lanka (Sri Lanka), which was nearly 200 yojanas, approximately 3,000 km.

The translation of the above reads: 3299 (yojanas) is the Earths circumference; this divided by 16 gives the distance between Lanka and Avanti (or Ujjayini.)

Similarly, Bhaskara II in his major treatise Siddhanta Siromani, had said that that the circumference of the Earth sphere is said to be 4967 yojanas.

Its diameter is 1581 1/24 yojanas. The surface area thereof is 7,85,034 square yojanas, for it is obvious that, as in the case of a spherical ball, the product of the Earths circumference and its diameter gives its surface area. (52), Bhaskara II wrote in Siddhanta Siromani.

Interestingly, Bhaskar was one of the first to provide an accurate mathematical model to derive the circumference of the Earth. According to his estimation, Earth was 4967 yojana and its diameter 1581.

As per Bhaskara II, a yojana is equal to the (distance between the two places*360)/(circumference-(difference in the latitudes of two places on the same terrestrial meridian in degrees).

In his book, Bhaskara II notes, The equatorial circumference of the earth multiplied by cos 0 and divided by R, or multiplied by 12 and divided by the hypotenuse of the right-angled triangle formed by the gnomon and the equinoctial midday shadow thereof, (hereafter called equinoctial hypotenuse), gives the circumference of the Earth parallel to the equator and passing through the locality (hereafter called the rectified circumference).

Estimating the earths circumference, Astronomer Nilakantha had accurately measured that the earths diameter is around 1050 yojans, i.e., 12,000 km.

His above work reads: The terrestrial sphere is 1050 yojanas in diameter and it stands in the sky in the centre of the celestial sphere, as the lowest point.

Here is another ancient text giving us the mathematical formulae to determine the circumference of the earth.

The above verse reads: Having fixed upon two places situated exactly north and south, determine their latitudes and the number of yojana-s between them. Then apply the rule of three: If their difference in latitudes causes the distance between the two places, how much (will the distance be) for the degrees in a circle (i.e., 360)? The result will be the circumference of the Earth. (12-13)

The next verse explains: If the difference in degrees of the two latitudes is the yojanas between them, how many will the yojanas be for 90, which is the latitude of Meru? This will give a quarter of the circumference of the Earth. (14).

Indian mathematicians first recorded the Decimal number system, which is the basis of modern mathematics today. The ancientand medievalIndianmathematical works, all composed in Sanskrit, consisted of several sutras discussing the Decimal system of numbers.

It was Indians who gavethe ingenious method of expressing all numbers by means of ten symbols the decimal system. The simplicity of the decimal notation facilitated calculation, and this system invented by the Indians made the uses of arithmetic in practical inventions much faster and easier.

In his work Aryabhatiyam, Aryabhata explains the decimal system of numbers, where the corresponding place value of a digit is always 10 times as great as the place value of the digit to its right.

The translation of Aryabhatas work, originally written in Sanskrit: Eka (units place), DaSa (tens place), Shatha (hundreds place), Sahasra (thousands place), Ayuta (ten thousand place), Niyuta (hundred thousand place), Prayuta (millions place), Koti (ten million place), Arbuda (hundred million place), and Vrnda (thousand million place) are, respectively, from place to place, every ten times the preceding. (2)

Astronomer-mathematicianSankara Varman, in the later part of the medieval era, also explained the decimal system that was enumerated by the likes of Aryabhata.

The translation of the above work reads: Eka (1), Dasa (10), Shatha (100), Sahasra (1000), Ayuta (10,000), Niyuta (or Lakh, 10s), Prayuta (10^6 ), Koti (10^7), Arbuda (10^8), Vrnda (10^9), Kharva (10^10), Nikharva (10^11), Mahapadma (10^12), Sanku (10^13), Varidhi (10^14), Antya (10^15), Madhya (10^16), Parardha (10^17) are numbers, each tenfold of the previous.

Here is a Yajurvedic verse that also cites the usage of the decimal system of numbers in the Vedic era. In addition, the Yajurvedic hymns mention the usage of the decimal value system in its ritual practises.

The translation of the hymn reads: O Agni, may these (sacrificial) bricks be my own milch-kine: one and a ten, a ten and a hundred, a hundred and a thousand, a thousand and a ten thou sand, a ten thousand and a hundred thousand, a hundred thousand and a million, a ten million, a hundred million, a thousand million, a ten thousand million, a hundred thousand million, a million-million or billion. May these bricks be mine milch-kine in yonder world and in this world.

In India, a system oftime measurementwas in place as early as in Early Vedic Era, dating 2500 BCE. There are several references to the measurement of time in sa and Upanishads.

Here is a Rigvedic hymn explaining the way time was measured in the Vedic age. The above hymn reads that the division of time in Vedic era was on the basis of Year, Months and Days.

The translation of the Rigveda hymn says: The wheel (of time) formed with twelve spokes revolves round the heavens without wearing out. O Agni! on it are 720 sons (viz. days and nights).

The above verse says time was divided into 12 spokes (hourly), with a combined 720 days and nights making it 360 calendar days.

Another Rig Vedic hymn says: The fellies (or arcs) are twelve; the wheel is one; three-(partitioned) are the axles (or hubs); but who knows it? Within it are collected 360 (spokes), which are, as it were, movable and unmovable.

According to Rig Veda, sage Dhrtavrata knew the twelve months. He also knows the month that is created, the Vedic documents reveals suggesting that the Vedic people knew and practised a sophisticated system of time consisting of 360 days, 12 months, which is almost identical to the Gregorian system of calendars which came thousands of years later and continued to be used even today.

Here is another Yajurveda prayers for hailing interstellar objects such as sun, moon, stars, responsible for formation of day and nights.

Oblation to (the intercalary month) Samsarpa, an oblation to the Moon, an oblation to the luminaries, an oblation to (the intercalary month) Malimluca, an oblation to the Sun, reads the Yajurveda verse.

Taittiriya Brahmanas also list the names of 13 months as per the Lunar system of calendar.

The names of the thirteen months: Aruna, Arunarajas, Pundarika, Visvajit, Abhijit, Ardra, Pinvamana, Anna- van, Rasa-van, Iravan, Sarvausadha, Sambhara and Mahasvan.

The Taittiriya Brahmanas also mentions the names of 24 half-months (pakshas):

The names of the 24 half-months are: Pavitra, Pavisyan, Puta, Medhya, YaSas, Yasasvan, Ayus, Amrta, Jiva, Jivisyan, Sarga, Loka, Sahasvan, Sahlyan, Ojasvan, Sahamana, Jayan, Abhijayan, Sudravina, Dravinodas, Ardrapavitra, Harikesa, Moda and Pramoda.

The Satapatha Brahmanas also mentions the Lunar year consisting of 354 days.

Verily, they who perform the Full and New Moon sacrifices run a race. One ought to perform it for fifteen years. But, in these fifteen years, there are three hundred and sixty full moons and new moons. And, there are, in a year, three hundred and sixty nights; it is the nights he thus gains. (10), reads the Satapatha Brahmana.

Further, He should then sacrifice for another fifteen years. In these fifteen years, there are three hundred and sixty full moons and new moons, and there are in a year three hundred and sixty days; it is the days he thus gains, and the year itself he thus gains. (11)

The authors have documented more than 3,000 verses in their magnum opus, that shed light on the major scientific accomplishments by Indians hundreds of years even before their western counterparts had conceptualised these ideas.

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Earth, space, time, and more: Read how Indian scholars had recorded astronomical facts centuries before they were discovered by Westerns - OpIndia

A team of astronomers studying distant exploding stars has found a way to tighten up the way the distance to them is measured and in doing so, tighten up measurements of how the Universe is expanding.

This kind of supernova is called a Type Ia. These occur when a small, dense white dwarf accumulates matter on its surface, eventually gathering so much matter the entire star undergoes nuclear fusion. The release of energy is absolutely colossal, equivalent to billions of times the Sun's output.

This is important for two reasons. Well, lots of reasons, but two we're concerned with here. One is that quantum mechanics makes the rules here, and all these stars explode when they reach a certain mass (about 1.4 times the Sun's mass), and that means they explode with about the same energy. That in turn means that if we see one close by or far away, we can measure its distance simply by determining how bright it got.

The other is that they are so bright they can be seen at vast distances, billions of light years away. The Universe is expanding, and more distant objects are moving away more rapidly. If we can measure these Type Ia supernovae with great accuracy we can determine how the Universe is expanding.

And, in fact, this has been done. In 1998 two different teams published results showing that the Universe is not just expanding but accelerating, expanding faster every day. It's not clear what is causing this, but we call it dark energy, and figuring out what this stuff really is made of is a major goal in astrophysics after all, we're talking the fate of the Universe here.

The problem is that not all Type Ias explode in exactly the same way. But this can be compensated for. As an example, some give off more energy than others, and in general those take longer to reach their peak brightness and fade. So, if you measure how long it takes to brighten and fade, you can determine its peak brightness, and then use that to get the distance.

This was what led to the breakthrough in 1998. But even so, there is still some wiggle room in the way they explode, some uncertainty in their brightness that means we still have some uncertainty in our measurements of how rapidly the Universe is expanding.

That's what the new work looks at. They found a new method to determine the distance to these exploding stars, and published two papers about it; the first deals with developing the method, and the second implementing it.

What they did is complex and clever. They looked at over 170 supernovae, taking spectra of them around the time of maximum brightness (in general they take a couple of weeks to get to their brightest, and then fade over many months). A spectrum shows how bright an object is in different wavelengths, which you can think of as colors; in this case many hundreds of colors. Different elements absorb and emit light at different wavelengths, which in turn can be used as diagnostics for the supernova about its temperature, speed, density, and so forth.

Instead of just looking at one characteristic, like how long it takes to brighten and fade, they could look at many, and found that overall the 173 supernovae they observed look remarkably similar near maximum brightness. They did find that some individual lines (astronomy speak for wavelengths where elements absorb or emit light) change from supernova to supernova, but if they looked at the light coming from between major lines (they literally called this the Reading Between The Lines method) all the supernovae looked incredibly similar.

This allowed them to create a computer model that compensated for differences between the individual supernovae due to external variations (like if one happened to be embedded in a dust cloud) which meant that any differences from one supernova to another must be due to something intrinsic, like its chemical composition or other physical factors.

They employed machine learning to find "supernova twins," where two different supernovae spectra had very similar spectra. Using those as a baseline they could then explore how the spectra differed and discover that in the end, only three factors affected how the brightness changes from supernova to supernova the light from calcium and silicon, and how rapidly the supernova debris expands.

By modeling these three factors they could then compensate for them, allowing them to more accurately predict just how bright a supernova gets. What they found is that their method is a significant improvement over the older one (using how long it takes the supernova to brighten and fade), and they are able to drop the distance uncertainty to only about 3%.

This is important! The better our distance measurement gets, the better we can measure the effects of dark energy on the cosmic expansion. As bigger telescopes come online in the next few years, more supernovae will be observed farther away. By applying this method, hopefully, those far distant explosions can be used even more accurately than before to understand what the Universe is doing.

It's an amazing thing that astronomers are trying to figure out how the Universe itself behaves, and even to understand its fate. But we are and we're getting better at it all the time.

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How far away are supernovae? Astronomers find a way to tighten measurements - SYFY WIRE

Using a new observatory, a team of Chinese astronomers have found over a dozen sources of ultra-high energy cosmic rays. And those sources arent from some distant, exotic corner of the cosmos. They come from our own backyard.

Ultra-high energy cosmic rays (UHECRs) arepretty energetic, typically millions of times more energetic than our most powerful particle accelerators. They are also relatively rare, and so astronomers have had a hard time pinpointing their origins.

But a team of Chinese scientists led by Institute of High Energy Physics (IHEP) under the Chinese Academy of Sciences dug deep into the origins of UHECRs using the recently-built Large High Altitude Air Shower Observatory (LHAASO). LHAASO is currently under construction in Daocheng in southwest Chinas Sichuan Province, but the astronomers were able to use the completed half of the instrument for an 11-month observation run.

They found a dozen sources of UHECRs, as well as some high-energy photons, including one with an energy of 1.4 Peta-electron volts (quadrillion electron-volts or PeV), the most energetic photon ever observed.

All those sources sit within the Milky Way.

These findings overturn our traditional understanding of the Milky Way and open up an era of UHE gamma astronomy. These observations will prompt us to rethink the mechanism by which high-energy particles are generated and propagated in the Milky Way, said Cao Zhen, chief scientist of LHAASO.

In addition, these observations will encourage us to explore more deeply violent celestial phenomena and their physical processes, as well as to test basic physical laws under extreme conditions, Cao said.

The sources of the UHECRs include a variety of natures own particle accelerators: newly-formed giant stars, supernovae explosions, massive star clusters, pulsar wind nebulae, and more.

The entire facility of LHAASO will be completed in 2021. With the completion of LHAASO and continuous data accumulation, we can anticipate finding an unexplored UHE universe full of surprising phenomena, He Huihai with the IHEP added.

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Astronomers Have Tracked Down the Source of High Energy Cosmic Rays to Regions Within the Milky Way Itself - Universe Today