S26E76: Hotter than the Sun // Feeding frenzy echo // Earth’s 19-hour long days

This is Spacetime Series twenty six, episode seventy six, for broadcast on the twenty sixth of June twenty twenty three. Coming up on Spacetime, discovery of a brown dwarf hotter than the surface of the Sun. Detection of a feeding frenzy echo omitted by our galaxy supermassive black hole two hundred years ago, and it seems the Earth's day was nineteen hours long for more than a billion years. All that are more coming up on Spacetime. Welcome to Spacetime with Stewart Garry. Astronomers have discovered what appears to be a brown dwarf that is hotter than the surface of the Sun. Amazing discovery reported in the Nature Astronomy and on the prepressed physics website archive dot org. Was detected orbiting a low mass white dwarf star catalogged as WD double zero three two minus three one seven. The white dwarf is located some one thousand, five hundred light years away and has about forty percent the mass of the Sun. It's orbiting brown dwarf subsequently named WD double zero three to minus three one seven b as between seventy five and eighty eight times the mass of Jupiter and a surface temperature of some eight thousand kelvin. By comparison, surface temperature of the Sun is five thousand, seven hundred and seventy eight kelvin. The extreme surface temperature of the brown dwarf is due to its orbital proximity to the white dwarf, taking just two point three hours to complete each orbit. White dwarves are the exposed cause of stars like our Sun, which have ceased nuclear effusion and lost their outer layers. Once these gaseous outer envelopes apart, staff all that's left is the white hot core at the center of the star. In the case of the Sun, it has a temperature of around fifteen million degrees and that's left to slowly cool over time. Now, white dwarf WD double zero three to minus three one seven is a lot cooler than that, with a temperature of around thirty seven thousand kelvin. However, the immense radiative heat coming off this core is baking the nearby brown dwarf due to its proximity. Site has first detected WD double zero three to minus three one seven early in the year two thousand using the European Southern Observatory's very large telescope, the VLT Chile. The authors noticed that something was tagging at the star, suggesting that it had a companion, but the wobble was too big to be a planet and too small to be another star, and that suggests that it was a brown dwarf. Orbiting so close means the brown dwarf would be gravitationally tirely locked to the star, with the same side always facing it. Scientists estimate surface temperatures on the day side of the brown dwarf would be somewhere between seven thousand, two hundred and fifty and nine thousand, eight hundred kelvin, while over on the night side of the brown dwarf, temperatures would range from one thousand, three hundred to three thousand kelvin. Brown dwarves have failed stars, objects which don't have enough mass to sustain the core hydrogen fusion process needed to make stars shine. However, brown dwarves do fuse deuterium, a heavier form of hydrogen which includes a neutron as well as the core proton and then nucleus, and those above sixty five Jovian masses can also burn lithium while most brown dwarves are born as such, others start their lives as spectral type M red dwarf stars, but over time they lose enough mass during the revolution the cease core hydrogen fusion, turning them from red dwarves into brown dwarves. Brown dwarves fit into a category between the largest planets, which have about thirteen times the mass of Jupiter, and the smallest spectral type M red dwarf stars, which have seventy five to eighty times the massive Jupiter zero point zero eight solar masses. And based on that, what this means is that this particular brown dwarf is very close to being a red dwarf this space time still to come. Detection of a feeding frenzy echo emitted by a galaxy supermassive black hole two hundred years ago, and it seems that Earth's day was nineteen hours long for literally billions of years. All that and more still to come on space time, astronomers have discovered that Sagittarius, a star supermassive black hole at the center of our mill y way galaxy, emerged from a long period of dormancy some two hundred years ago to undertake a feeding frenzy. A report in the journal Nature claims the monster, which has some four point three million times the mass of our son, awakened as material came too close and was then torn apart by the black hole's immense gravitational title forces. The feeding frenzy lasted for about a year at the beginning of the nineteenth century, before the gravity world once again entered a state of quiescence. The studies lead author, Frederick Marin from the Strasbourg Astronomical Observatory, says no effect was filled on Earth from this event. A Sagittarius A star is some twenty seven thousand light years away from our solar system. However, the X ray echo detected by Marilyn colleagues, which was emitted around two hundred years ago, reveals that the original intensity was at least a million times greater than that currently emitted by Sagittarius A star. To get an idea of the increase in intensity of X rays when the black hole emerged from its queercent state, it's as if a single glow worm hidden deep in a forest suddenly became as bright as the sun. The findings explain why galactic molecular clouds knee Sagittarius A Star are shining more brightly than usual. It's because they're reflecting the X rays emitted by Sagittarius A Star two hundred years ago. To carry out their research, the authors used NASA's XP Imaging X Ray Plematory Explorer's satellite, which was for the very first time able to detect the polarization of this X ray light with great precision and also determine its source, something which had previously been impossible. Rather like a compass, the polarized X ray light points directly to its source, Sagittarius A star. Even though the latter is now virtually extinct, scientists are continuing to study Sagittarius A Star in order to try and determine just how much physical mechanisms are required for a black hole of the size to switch from a queercent state to an active one. And we'll keep you informed this spacetime still to come. Well, the day may last twenty four hours on Earth now, but for a billion years, it seems an Earth Day was just nineteen hours long. And later in the Science report, Facebook owner Mark Zuckerberg says it was the scientific establishment that called on Facebook to censor posts that turned out to be true. All that and more still to come on Spacetime and You study suggests that Earth's current twenty four hour long day didn't gradually happen as the planet's rotation slowed down, but instead changed in spurts. Earth's rate of rotation is governed by various factors, including the gravitational pull of the Moon. Scientists know that the length of an Earth day was a lot shorter in the past because the Moon was closer. Over time, the Moon has stolen some of Earth's rotational energy in order to boost itself into a higher and more distant orbit. It's a process which is continuing today, with the Moon's rate of escape being around three cinematists per Earth year. One of the studies authors, Over Kushner from Curtain University, says most models of Earth's rotation predict that the day length was consistently shorter and shorter going back in time, but his report in the journal Nature shows the hypothesis of a slow and steady change in the length of a day over time isn't matching the evidence. And I guess the first question that raises is how do researchers measure ancient day length. In past decades, geologists used records from special sedimentary rocks preserving very fine scale layering in tidal mud flats count the number of sedimentary layers per month caused by tidal fluctuations and the number of hours in an ancient day. But such title records are rare and those that are preserved are often disputed. Luckily, there's another means of estimating the length of a day. Crystal stratigraphy is a geological method that uses rhythmic sedimentary layering to detect astronomical Milinkovitch cycles that reflect how it changes in Earth's orbit and rotation affect climate. Two Milinko cycles, procession and obliquity, are related to wobbles and tilt in the Earth's rotation axis in space. The faster rotation of early Earth can therefore be detected in shorter procession and obliquity cycles in the past. The authors took advantage of a recent proliferation of Milenkovitch records, with over half the data French in times generated in the past seven years, and this gave them a chance to test an alternative hypothesis about planet of this paleo rotation. One unproven idea is that the Earth's length of day may have stalled at a constant value when the distant past. You see, in addition to tides in the ocean related to the pull of the Moon, Earth also has solar tides related to the atmosphere heating up during daytime. Solar atmospheric tides are not as strong as lunar oceanic tides, but this would not always have been the case. When Earth was rotating faster in the past, the tug of the Moon would have been much weaker, and unlike the pull of the Moon, the Sun's tide instead pushes the Earth, So while the Moon slows earth rotation down, the Sun speeds it up. Yesha says this means that when the two opposite forces equal each other, it created a tidal resonance which would have caused Earth's day length to stop changing and remain constant for some time, and that's exactly what the new data compilation appears to show. Earth's day length appears to have stopped its long term increase and then flatlighted at around nineteen hours, roughly between two and one billion years ago. Now, interestingly, the timing of this term forestalling intriguingly lies between two of the largest rises in the planet's oxygen levels. A new study thus supports the idea that Earth's rise to modern oxygen levels had to wait for longer days for photosynthetic bacteria to generate more oxygen each day. Casha says, it's fascinating to think that the evolution of Earth's rotation could have affected the evolving composition of the planet's atmosphere. There's several factors, I guess. I mean, the Earth is spinning all the time. The Moon plays a very important role in blowing down the rotation of the Earth because they're attracting each other, and the Earth is rotating around the Sun, and all this energy is getting conserved in this system. And so if energy is getting transferred from the Earth to the Moon, then the Earth has to slow down. It's not just the Sun and the Moon which control the Earth's rate of rotation. There's also something else. The Malenkovit cycles tell us about them. You know, that's a very very interesting question, first of all, because you know, in our paper, we took these certain aspects together to get information on the length of day of the Earth, which is related very much on the rotation. But on the other hand, where you mentioned the milanko which stuck, they play a very important role in Earth climate, in the insulation, let's say on several places on the Earth, and the milanko which tacks are related to not just one thing, but to several aspects of the way Earth is spinning. Like it's not spinning in the plane of all the rotations, but it has like an angle, so it processes around this angle. That's that's the procession. It's also the rotation around the Sun. It's not a circle but the ellipse, and this ellipse is not closed, so this changing is affecting the insulation. And yeah, also the obliquities of this angle is also plays a role. So these are the three main things, and all these are heavily related to the insulation. And has been shown that you can see this in geologic records, so that you can see climate cycles in this with this wavelength of the milanko which sycle. And what's your research involved in, Yeah, that's a bit of a story because I'm the astronomy is I'm basically I'm a paleomagnetist, So what I do most of the time is that I'm taking this more sampus. I measured the magnetization direction in this sampus. Then I try to figure out the magnetization direction during the time of formation of this rock, and then I reconstruct the continent where I took this sampus. So how Australia moved through Earth history, That's kind of my main thing. On the other hand, I'm using the same technique to do like using magnetos statigraphy, like measuring polarities throughout like a section in like an outcrop section. So what happens is as magma cools and solidifies, it develops a yeah and that will solidify in a certain direction. That lets you know what direction the magnetic poles of the Earth were at the time that rock solidified. It can use that like a strata to date various rocks. I mean two things, Like because the direction of the magnetic field right now is pointing towards the north pole, so I can calculate the magnetic north pole. But I and also use the inclination to tell me where I am, Like when I'm at the equator, the magnetic field lines will be perfectly horizontal, whereas here in Australia. I think they're like dipping like forty degrees or so, and this is related, so I can calculate the paleolatitude where this place was. On the other hand, the magnetic field reverses his polarity every now and then, and I can use this pattern to try and get the age. Doing this like having a geologic section where I tried to figure out the age. I can also measure magnetic parameters to identify these Milanko Wich cycles, which then gives me the like one of the only controls on the duration of a certain outcrop. So we measured We worked on drill courts from the Vulkyrie formation in Northern Australia. This is like one point five billion year old sedimentary rocks, and there is no chance in deciding very precisely how much time is conserved within a certain certain interval. The absolute dating is not is not precise enough. But the Milanko Witch cycles can be used to do this kind of things, and that's what you're using magnetic parameters. That's more what I'm doing. And the study we did now is like using more of this study which gives us Milankovich cycle which can be used to calculate the length of day and then the Earth Moon distance and these kind of things, because there the procession is related to the length of day. And by using that you were able to find out that it wasn't a gradual progression from a shorter day to the twenty four days we have now you found that, yeah, stuck on a nineteen hour day for a while. They last a beat a billion years. The thing is, we are doing these things and this interesting obviously, that this evolution of length of day. But then we looked at this very recent compilation of newer data got available and hours included, and then we had a look more into these more theoretical papers about all these rotational theories and the tidal aspect, and then we found suggestions that the moon is one side of the story, which which is the most dominant, the tidal force of the Moon on the Earth rotation. On the other hand, the Sun is heating up the atmosphere and this is creating another force in the opposite direction, in resonants mode. This is not our research is other people have suggested this and they said, if these two forces are in equilibrium, there might be a resonant state which could be as long as a billion years or so, we don't know exactly how long. And we took this up and had a look at this, and we did a very basic statistical step change analysis, and we got this interval of fairly stable length of the evolution of about nineteen hours a day. And I mean, there's a lot of uncertainly is still big there. But the fact that we found this with actual data, actual real constraint, which is similar to what other people have suggested, that's I think that's the most interesting part of this study. Actually, what do you think caused the stalls? That's a long stretch of time for the natural slowdown of earth rotation to holes. Yeah, definitely. I mean, you know, these people suggested already that if you're in reason and state, you will stay there and the length of state won't change anymore. What they say, the more interesting thing is how you get out of this mode, because one question resonance, and this mode where the atmospheric tight and the lunar tider can sting out each other, you will stay there. But what they were saying you might need sudden increase of atmospheric temperature, which could get you out of this and there was like two phases of maybe not complete snowball Earth, but a lot of parts of the Earth were covered in ice, and once this ended because of some reasons also debates a lot of research going on there. But once you get out of this, you might have these couple degrees of sudden temperature rise and this might have caused the exiting of this resonance state. On the other hand, our data now might indicate this was a bit earlier than these snowball events, so we might reconsider what and find other mechanisms to break this resonance state. With more data coming available, our analysis might change slightly and we might get more closer to this change point getting out of this resonance state or in the range where the other people have suggested this so closer to this Noble Earth event. But it might also be that we have to look for another feature, which yeah, which is also interesting because one point one point three one billion years ago up to this Noble Earth event, that's a very interesting period of time where we're working more from the paleogeographic side of things, where a lot of things happening there and a lot of also with the magnetic field. This would be interesting how this field evolves in the coming time. And if there's no new new aspects evolving there, that's over Kasher from Curtain University and this space, time and time. That will take a brief look at some of the other stories making us in science this week with a science report, Metta and Facebook CEO Mark Zuckerberg says scientific establishment asked his platform the sensor posts about COVID nineteen, claiming they were misinformation, but which ended up being either true or at least open to debate. The admissions were made on the Lex Friedman podcast while Zugerberg was discussing the problems Facebook faced on removing misinformation. Zuckerberg says there simply hadn't been time to fully vet a bunch of the scientific assumptions. He said the establishment encouraged him to enforce what he called shaky facts, asking for a bunch of things to be censored that in retrospect ended up being true or at least opened a more debate. At the height of the COVID nineteen pandemic in twenty twenty one, Zuckerberg admitted that Facebook had removed some eighteen million posts, claiming that what was being claimed at the time was misinformation about the virus. Last year, several US state attorney generals compiled evidence alleging that Zuckerberg coordinated with White House health spokesman Anthony Fauci to discredit and suppress the hypothesis that the COVID nineteen virus may have originated in the Wuhan Institute of Virology. It has since been established that Fauci's National Institutes of Health was funding gained a function research on bat viruses at the Wuhan lab. Earlier this year, the US Department of Energy concluded that the pandemic was most likely leaked from the Wuhan Institute of Rology, thereby supporting the earlier conclusions of a separate investigation by the FBI. A new study has found there really is a difference in your heart health depending on whether you're gay, straight, or buy. A report in the Journal of the American Medical Association Cardiology claims bisexual biological females may have worse cardiovascular health than their heterosexual peers, while gay men have better cardiovascular health than straight men. The study assess the cardiovascular health of over twelve thousand people and then looked at how their scores varied with sexual identity. The authors say the data suggest that there's a need for tailored interventions to help improve the cardiovascular health of sexual minority adults, especially bisexual biological females. Japan has begun testing new facilities designed the discharge treated nuclear or wastewater into the North Pacific Ocean. The contaminated water had been used to cool the melted reactors at the Fukishimidiachi Nuclear Power Plant, but after filling more than a thousand tanks, storage is expected a rich capacity early next year. Japan says it's now treated water to the point where officials say it's no longer harmful, and so it now intends to dilute and release that water into the Pacific. Back in March twenty eleven, three of the six nuclear reactors at the Fukishimidachi Nuclear Power Station were destroyed after fourteen meter high tsunami waves from Tohoku undersea earth inundated the facility. The earthquake had already triggered an automatic shutdown of the power plants three operational nuclear reactors, the other three having already been shut down for maintenance. However, the tsunami flood had damaged the power station's emergency diesel generators. Those generators were needed to pump water to keep the reactor cause cool during the shutdown. This allowed heat to build up inside the three reactor cause that eventually triggered a meltdown of the nuclear fuel rods inside the reactor, the exact scenario which Hollywood portrayed in the movie China Syndrome. In the case of Fukushima, the Malta nuclear fuel rods melted through the base of the reactor pressure vessels and then flowed onto the bottom of the primary containment vessels, forming Medusa. The melting fuel rods also produced vast amounts of pressurized hydrogen gas as a byproduct. This eventually reached a critical stage, venting out of the reactor pressure vessel where it mixed with ambient air, and this eventually rich concentration limits in two of the three reactor buildings and consequently exploded, spreading vast amounts of contaminated material over the surrounding countryside. A new study has found that babies born to women who used traditional Chinese medicine were twice as likely to have birth defects compared to mothers using no medicine or those using conventional Western medical treatments. The findings are reported in the journal Actor Obstetrica at Gana Collegiate Scandinavia compared sixteen thousand, seven hundred and fifty one women from twelve different provinces across China. But as Timmentum from Mystery and Skeptics explains, there were some serious problems in the way the study was carried out. To day in the university in Shanghai did a test of about with a sixteen thousand, seven hundred women from twelve different promises in China are people giving no medicine, Western medicine and traditional Chinese medicine for women during their practices, And what they were saying is that baby is born to women who underwent traditional Chinese medicine treatments were twice as likely to have birthday effect compared to mothers who did not, whether they had Western medicine or were no medicine at all. Pretty shocking result. They say that a lot of the traditional Chinese medicines carry quote as significant risk of fetal malformations. They urged expected mothers to use the therapies cautiously, so in other words, this is a Chinese university doing a study of Chinese people across China different provinces of how they reacted and what the outcome of the children were. To get twice as many problems with the traditional Chinese medicine, you say, oh, hang on here him, there must be something wrong. There is a trouble, a problem with this study. And as always, keptics like to point out problems with scientific studies even as much as they do for non scientific studies. This was a group of sixteen thousand, nine twelve thousand, three hundred of whom did not take any medicines. Four thousand were given Western medicine and one hundred and eighty nine used traditional medicine. Now one hundred and eighty nine is not a particularly large sample. The four thousand to god western medicine is this season study. It doesn't seem to be a balanced study, and that's a shame because it's a great idea. It's sad for the babies. Obviously, it's unfortunate that the sample they chose. Maybe that number of people in the sample was chosen by the patients. Maybe most of them wanted to do Western medicine rather than traditional Chinese medicine. Who knows. That's the trouble is, there's not enough information from the report that I've seen to actually show what's happened. The interesting thing is they said that of this one hundred and eighty nine women who were given traditional Chinese medicine, they were looking at an average rate of thirty four point six fetuses per thousand that had congenital malformation. So that's a three and a half percent I think it is working out of people, which is not compared to one and a half percent of those who were not exposed to medicine. So it's a bit of a difference whether it's a statistical statistically significant difference considering the lone number of people you're talking about, and when you're talking about pers thousand fetuses, there's not an actual thousand fetuses amongst the traditional Chinese medicine users. So it's an extrapolation from a fairly small sample base. But this case interesting cons This is one case where it does nay more words. That's timendum from Australian Skeptics and that's the show for now. Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts, iTunes, Stitcher, Google Podcast, pocket Casts, Spotify a cast, Amazon Music, bytes dot com, SoundCloud, YouTube, your favorite podcast download provider, and from Spacetime with Stewart Gary dot com. Spacetime's also broadcast through the National Science Foundation on Science Zone Radio and on both iHeartRadio and tune In Radio. 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