Best View Yet of the Birth of a Black Hole

Stuart: This is Spacetime Series 25, episode 111 for broadcast on 19 October 2022. Coming up on Spacetime astronomers given one of their best views yet of the birth of a black hole the largest known asteroid impact on Earth and an um Australian to grow plants on the Moon. All that and more coming up on uh space time.

Guest: Welcome to spacetime with Stewart gary.

Stuart: Astronomers have been given one of their best views yet of the birth of one of the Universe's most infamous monsters a black hole. Their findings were reported in the journal Nature describe a super luminal jet bowling through space at speeds of greater than 99 97% the speed of light propelled by a titanic explosion as two neutron stars collide. The event, named GW 17 817, was first observed in August 2017 by LIGO, the laser interferometer gravitational wave observatories in Louisiana and Washington state and by Virgo, a European gravitational wave observatory in Italy. The collision originated in the shell of an elliptical galaxy that is, NGC 49 93 located about 140,000,000 light years away in the constellation Hydra. The blast released as much energy as any supernova explosion. Independently, a short two second GammaRay burst designated as GRB 1700 and 817 A was detected by the Fermion Integral GammaRay Space telescopes beginning one 7 seconds after the gravitational wave merger signal. This was the first combined detection of gravitational waves and gamma radiation from a binary neutron star merger. The aftermath of this massive collision was collectively seen by more than 70 observatories around the planet as well as in space. And it was monitored right across the electromagnetic spectrum as in addition to the gravitational wave detection. Consequently, this has heralded a significant breakthrough for the emerging field of time. Domain and multimessenger astrophysics and the use of multiple messengers like light and gravitational waves studied the Universe as it changes over time. It was also a major watershed in science's ongoing investigation of these extraordinary collisions. Astronomers were able to aim NASA's Earth orbiting Hubble Space Telescope at the site of the explosion two days after the first signals were received. By then, the two neutron stars had collapsed forming a stellar mass black hole. Its powerful gravity had begun pulling in all the material around it. All this material formed a rapidly spinning accretion disk and the accretion disk began generating jets moving outwards, perpendicular to the black hole's disk. The roaring jet smashed into and swept up material in the expanding shell of explosion debris. This included a blob of material through which the jet emerged. Now, while this event took place back in 2017, it's taken several years for scientists to come up with a way to analyze the Hubble data together with the data from the other uh. Telescopes in order to paint this full picture we now have. So the Hubble observations were combined with observations from multiple National Science Foundation radio telescopes working together to provide a very long baseline interferometer. The radio data was taken on day 75 and again on day 230. After the explosion. The study's lead author, Vanella P. Muli from Caltech in Pasadena, California says he was amazed that Hubble could provide such a precise measurement rivaling the precision provided by the radio telescopes of the Very Long Baseline Interferometer. The authors used Hubble data, uh, together with data from the European Space Agency's Gaia spacecraft in addition to the Very Long Baseline Interferometer to achieve extreme precision. Taking several months of careful analysis of the data to make their measurements. By combining all these different observations the authors were able to pinpoint the exact explosion site. Now, uh, interestingly the Hubble measurements showed the jet appeared to be moving at an apparent velocity several times the speed of light. And the radio observations showed that the jet had later decelerated to an apparent speed of four times faster than the speed of light. Of course, in reality, nothing can exceed the speed of light. So the superluminal motion is, in fact, an illusion. It comes about because the jet is approaching Earth at nearly the speed of light and the light, it admits at a later time has a shorter distance to go. So, in essence, the jet is chasing its own light. In actuality, more time has passed since the jet's mission of the light and appears to the observer and this causes the object's velocity to be overestimated. In this case, seemingly exceeding the speed of light. When everything is calculated out correctly. It turns out the jets were actually moving at around 99 97% the speed of light when they were launched. The new Hubble measurements, combined with a Very Long Baseline Interferometer measurements announced back in 2018 greatly strengthened the long presumed connection between neutron star mergers and shorts Euration GammaRay bursts. That connection requires a fast moving jet to emerge which has now been measured in GW 17 817. The work paves the way for more precision studies to be made of neutron star mergers being detected by LIGO Virgo and Japan's new Cargo Gravitational Wave Observatory. With a large enough sample size over coming years relativistic jet observations might provide another line of inquiry to measuring the universe's rate of expansion known as the Hubble constant. See, at the moment, there's a huge discrepancy between Hubble constant values as estimated in the early universe and in the nearby universe. In fact, it's one of the biggest mysteries and problems facing astrophysics today. After all, how can we determine where we're going if we don't know how fast we're going there? The differing values are based on extremely precise measurements of type One A or thermonuclear supernovae exploding stars all of similar mass which explode at different distances and therefore allow you to use them as distance ladders to determine the acceleration rate of the universe as opposed to the cosmic microwave background radiation measurements by ESA's Planck satellite which measured the earliest light in the universe just 3000 years after the Big bang 1380 2 billion years ago. More views of relativistic jets will add information for astronomers trying to solve the puzzle. This report from NASA TV.

Speaker C: Astronomers using NASA's Hubble Space Telescope have found a jet propelled through space at nearly the speed of light, but the titanic collision between two neutron stars, which are the collapsed cores of massive supergiant stars. The explosive event observed on August 17, 2017 was the first combined detection of gravitational waves and gamma radiation from the merger of binary neutron stars. This discovery prompted scientists to quickly aim Hubble at the site of the explosion. A total of 70 observatories around the globe and in space collectively gathered data across the electromagnetic spectrum of the merger's aftermath. Astronomers used Hubble's capabilities to precisely measure the position and movements of the explosion's shockwave. They were trying to see how the shockwave's physical properties changed over time. Combining Hubble observations with that of several other telescopes allowed researchers to pinpoint the explosion site 130,000,000 lightyears away. The data suggests the blast shock waves traveled along a narrow beam confined by powerful magnetic fields. The resulting jet smashed into and swept up material in the surrounding interstellar medium. This material included a mass radiation through which the jet emerged. As the jet moved away from the site of the explosion, the mass moved outward. This work paves the way for more precise studies of neutron star mergers. More observations like this one help us understand more about the universe.

Stuart: This is spacetime still to come the largest known asteroid impact on Earth may have been even bigger than previously thought, and at least twice the size of the one which killed all the nonevian dinosaurs 66 million years ago. The massive space rock, now estimated to be between 20 and 25 km wide, slammed into planet Earth some 2 billion years ago in what is now southern Africa, creating the Gargantuan Redifort crater, located some 120 km southwest of Johannesburg. The massive scar left from the impact produced a crater some 159 km wide, making it the biggest visible crater on Earth. However, that's far smaller than the famous 180 km wide chicksA Lube crater, which is buried under Mexico's Yucatan Peninsula. It was formed 66 million years ago by the impact of the twelve km wide KT boundary event. Dinosaur killing asteroid. Scientists believe that 2 billion years worth of erosion would have removed much of Redefort's original size. But speculation remained as to how big it would have originally been and consequently how big the asteroid must have been that caused it. Now a new study reported in the Journal of Geophysical Research Planets has recalculated the size of the Varetafort crater, including that it would have been between 250 and 280 kilometres wide when it was formed. The study's lead author, Natalie Allen from Johns Hopkins University, says understanding the largest impact structure we have on Earth is critical. Having access to the information provided by a structure like ready for it crater provides scientists with an opportunity to test their models and their understanding of the geological evidence, so they can better understand asteroid impacts on Earth, uh, as well as beyond. Now, for the authors, the big problem was not only the 2 billion years of erosion by wind and water, but also the creation of lots of newer rock formations covering much of the original crater, so that only really small sections of the rim are still visible today, making it even harder to tell how big the crater really was. However, by studying the minerals surrounding the crater, scientists were able to trace the defamations and shock fractures in crystals like quartz and zircon, which were caused by the impact, thereby creating a better estimate of the true blast radius. Uh, based on those measurements, Allen was able to calculate the impact that would have been between 20 and 25 kilometres wide. That's twice as big as the KT boundary event, dinosaur killing asteroid. She says it may also be traveling much faster, between 72,000 and 90,000 km/hour when it hit the planet. That means the impact would have been even more severe, potentially the single largest energyrelease event in Earth's history. However, unlike chicksA Lube, which killed 75% of all life on Earth, the Reddified impact didn't leave a record of mass extinction or global forest fires. That's because the only life on the planet 2 billion years ago were single cell organisms. Still, the impact would have affected global climate potentially far more extensively than chicksilub did. So there's still lots of study to do. This is spacetime. Still to come, an Australian project to grow plants on the moon. A, uh, Japanese rocket explodes during launch, and later in the science report, a new biodegradable material designed to replace conventionally used plastics. All that and more still to come on um, space time. Australian scientists have announced plans to grow plants on the moon to help pave the way for future lunar colonies. Biologist Brett Williams from the Queensland University of Technology says the seeds would be carried aboard the Bere Sheet two spacecraft, which is now being built by an Israeli nonprofit team. They'd be planted in a sealed container, which would be watered after landing on the moon and then monitored for signs of germination and growth. The Australian Lunar Experiment promoting Horticulture, or Aleph, project, is an early step towards growing plants for food, medicine and even oxygen production on the moon. All of which will be crucial for establishing human life on our neurocellestial neighbor. Aleph, meaning one or A in the Hebrew alphabet, will be the first of a series of experiments to investigate whether plants can not only tolerate, but maybe even thrive on the lunar surface. The projects at international collaboration involving not just the Queensland University of Technology, but also RMIT University, the Australian National University and the Bengurian University in Israel. Space Al says the Beresheet two moon mission would launch in late 2024, touching down on the lunar surface in early 2025. Spacecraft would include an orbiter and two landers. Seven countries, including Israel, Australia and the United Arab Emirates, will participate in the project. Japan suffered a major launch failure with its Epsilon rocket exploding during the final stage of its flight to orbit. The 24 meters M tall solidfueled rocket had taken off from the Uchinora Space Center, uh, in the southern Kagashima region. It was carrying the 110 kg rays. Three rapid Innovation Payload demonstration satellite. Satellite was loaded with seven experimental technology payloads and five rideshare CubeSats. Initial reports indicate the rocket's first and second stages performed nominally. However, the third stage failed, forcing mission managers to issue a selfdestruct order. Uh. The Japanese aerospace exploration agency JAXA are now trying to determine exactly what went wrong. This is Spacetime and time now to take another brief look at some of the other stories making use in science this week with a science report. A new study shows that women with obesity can improve their heart health using a combination of timerestricted eating and high intensity interval training. Timerestricted eating involves eating all the food for the day within a ten hour window. Researchers conducted a randomized controlled trial involving 131 women split into four groups. One group of participants were involved with only high intensity interval training. The second group undertook, um, only time restricted eating. The third group involved both time restricted eating and high intensity interval training, and the fourth group acted like a control, doing none of the above. The trial lasted a total of seven weeks. The findings, reported in the journal Cell Metabolism, show that people in the time restricted eating and High Intensity Interval Combination group were able to improve their average longterm blood sugar levels, reduce their fats, and increase cardio fitness compared to the other tested groups. In a separate study, researchers also found that time restricted eating alone is an effective strategy for shift workers such as firefighters, in order to improve heart health, glucose levels and blood pressure. Engineers with the University of New South Wales have built a new high speed motor which has the potential to increase the range of electric vehicles. The Interior Permanent Magnetic Synchronous Motor Traction Drive prototype achieved speeds of around 1000 revolutions per minute, far exceeding the maximum power and speed normally achieved by these novel motor m designs. Researchers say the new design is able to produce very high power density, which is beneficial for electrical vehicles in reducing overall weight and therefore increasing range. Interior permanent magnetic synchronous motors have magnets embedded within their rotors in order to create a strong torque for an extended speed range. However, existing versions suffer from low mechanical strength that's due to the thin iron bridges in their rotors, which limits their maximum speed. The University of New South Wales team overcame these issues with a new rotor topology, which significantly improves robustness while also reducing the amount of rare earth materials needed for their production scientists with the University of California, San Diego, have developed the new biodegradable material, which they say is designed to replace conventionally used plastics. A report in the journal Science of the Total Environment claims that the new polyurethane foams have been proved abide AGRADE in landbased composts and in seawater. Uh, the researchers found that assortment of microorganisms, a mix of bacteria and fungi which will colonize polyurethane foams and use them as a food source. The results showed that the material started to degrade in as little as four weeks. The discovery could help address the growing environmental health threat posed by plastic pollution, from grocery bags in the deep sea, to microplastics in food supplies, and even in your bloodstream. In 2010, researchers estimated that some 8 billion plastic enter the ocean every year, mostly from China. That trash builds up into giant gyres like the Great Pacific Garbage Patch, which already covers an area of more than 1.6 million. Highlights of the past twelve months have been Sony's new prototype, eight K VR headsets, which feature a pair of miniaturized 4K OLED panels mounted in the one package. Our uh, technology editor, Alex Harrow Roy from Ity.com, says they look great.

Guest: This is an ultrarealistic eight K VR headset prototype. This headset promises that you can share experiences with an overwhelming sense of reality. So it projects a uh, high def 3D space and achieves high resolve. 4k with one eye and eight K with both eyes. It's got twice the pixels of your OLED phone. And these pixels are so small that you can't see them, so you don't get that screen door effect. And they pair CMOS image sensors with 4K OLED displays, and they've got ultra low processing times. So this is so you don't feel busy. And they have this thing called latency correction. So the video looks incredibly smooth and realistic. It's still on your prototype, it's not on sale yet, but it could commercialize this if you wanted to. And it's um, stuff that will, in theory, be released this decade.

Stuart: Is that just for gaming, or will it have uses in other areas as well?

Guest: Well, I mean, if you've put on a uh, VR headset, and you've been sort of underwhelmed Philips computery, I mean, imagine putting on a headset and thinking what you're seeing.

Stuart: I find them addictive. Well, for me they're addictive. Once I get them on, I don't want to leave that world. This is all about me, when you think about it.

Guest: Well, that had movies, they've had movies like that about what was called surrogates. But um, we've also had the headsets that they put on in the Neuromancer books or Johnny Mnemonic, the movie. And uh, this is a decade, we're going to have VR and AR, uh, and mixed reality. Absolutely. Communication, gaming. And when you're overlaying information on reality, you get to a point where, I mean, if you think people are to do their phones now, wait till I've got these headsets, especially the ones you can see through, so you can navigate and continue getting information. And, uh, it'll just be a game changer. You won't be able to live a modern life without having this headset on.

Stuart: Yeah, that was what I thought Google Glass was going to do.

Guest: Well, Google Glass came out last decade and it, uh, was just too early for its home technology. Told you it wasn't good enough, wasn't high res enough, they couldn't display enough information. I mean, they did what it did. And I saw a wonderful video where this lady was able to use she was a low vision or maybe no vision, but look, she was up to navigate around and she'd go into shops and look at items like a bottle of milk or whatever it was. And the system could tell her what she was looking at and could read the text, uh, if it could detect it on whatever she was looking at and tell her about it. So that was a form of bionic sound controlled, right?

Stuart: The next generation beyond that would naturally be able to do what Google does now with the phone, but with Google with a form of glass and let you look at the label, no matter what language it's in, tell you what it is, tell you what its calorie count is, everything.

Guest: You'll be able to tell you everything about it, search about it, and of course, in your ear you have a, uh, headset that's giving you all this information discreetly and privately. And, uh, the experience Google offered ten years ago was, um, primitive compared to the advances I have today. So yeah, this kind of technology is absolutely incredible and it'll be helping more and more people. And by the end of this deck, at this time in ten years, I mean, we'll just remember these little quake rectangles of glass we appear at. And if we wanted to look at AR things, we had to hold them up to our eyes and move things around them. We couldn't see an entire vista in front of us. We just had to look through a little six or seven inch piece of glass to see this virtual world. It'll seem very, quite indeed.

Stuart: That's alexaharovroit from ity.com. And that's the show for now. Space Time is available every Monday, Wednesday and Friday through Apple Podcast, itunes, Stitcher, Google Podcast, podcasts, Spotify, Acast, Amazon Music Bytes.com, SoundCloud, YouTube your favorite podcast download provider uh and from Spacetime with Stuartgary.com spacetime is also broadcast through the National Science Foundation on science owned Radio and on both iHeartRadio and tune in Radio. And you can help to support our show by visiting the Spacetime Store for a range of promotional merchandising goodies. Or by becoming a Spacetime patron, which gives you access to triple episode, commercial free versions of the show, as well as lots of bonus audio content which doesn't go to Air. Access to our exclusive facebook group and other rewards. Just go to spacetime with Stuartgary.com for full details. And if you want more spacetime, please check out our blog, where you'll find all the stuff we couldn't fit in the show, as well as heaps of images, news stories, loads of videos and things on the web I find interesting or amusing. Just go to spacetime with Stuartgarry Tumblr.com. That's all one word and that's tumblr without the e. You can also follow us through at stuartgary, on Twitter, at Spacetime with Stuart Gary on Instagram, through our, uh, Spacetime YouTube channel and on Facebook. Just go to facebook.com spacetime with stuartgary and Spacetime is brought to you in collaboration with Australian Sky and Telescope magazine, your Window on the Universe. You've been listening to Spacetime with Stuart Gary. This has been another quality podcast production from Bitesz.com