S27E88: Earth's Wobble, The Three-Body Dilemma, and SpaceX's Setback

[00:00:00] This is SpaceTime Series 27 Episode 88, full broadcast on the 22nd of July 2024. Coming up on SpaceTime, how climate change is altering Earth's rotation, an in-depth look at the trouble with the three-body problem, and SpaceX's Falcon 9 rocket grounded following a rare mid-flight failure.

[00:00:22] All that and more coming up on SpaceTime. Welcome to SpaceTime with Stuart Gary. A new study has shown how human activity is affecting the planet's rotation. It's all happening because of climate change. It's causing ice masses in Greenland and Antarctica to melt.

[00:00:59] That causes the water from polar regions to flow into the world's oceans, and then centrifugal force generated by the spinning of the planet pushes some of that extra water towards the planet's equator. Now two new studies, reported in the journals Nature Geoscience and the Proceedings of the

[00:01:15] National Academy of Sciences PNAS, have shown that these effects mean a shift in masses taking place, and that's affecting the Earth's rotation. The study's lead author, Benedikt Söder from ETH Zurich, says it's kind of like when

[00:01:29] a figure skater does a pirouette, first holding their arms close to their body and then stretching them out. The initial fast rotation becomes slower because the masses move away from the axis of rotation, increasing physical inertia.

[00:01:44] In physics, this is referred to as the law of the conservation of angular momentum, and it's the same law which governs the Earth's rotation. As you'd expect, if the Earth turns more slowly, it means the days are getting longer.

[00:01:59] What it means is that in addition to affecting the environment and life on the planet, climate change is also affecting the length of a day on Earth. In the PNAS study, Söder and colleagues have shown that climate change really is increasing the length of a day.

[00:02:14] Now right now it's only by a few milliseconds, but that will change over time. It's happening because water is flowing from the poles to lower latitudes, thus slowing down the speed of rotation. Another cause of this slowdown is known as tidal friction that's triggered by the Moon's

[00:02:31] orbit around the Earth. However, this new study comes to a surprising conclusion. If humans continued to emit more greenhouse gases and the Earth warms up accordingly, this would ultimately have a greater influence on the Earth's rotational speed than the

[00:02:45] effects of the Moon, which has been determining the increase in the length of a day on Earth for billions of years. Söder says the study shows that humans have a far greater impact on the planet than what they realise.

[00:02:59] The second study, reported in the journal Nature Geoscience, shows how shifts in the mass of the Earth's surface and its interior not only changes Earth's rotational speed and the length of a day, it also alters the planet's axis of rotation.

[00:03:13] This means the points where the spin axis meets the Earth's surface begin to move. And researchers can observe this polar motion, which over a longer time frame comes to several metres per hundred years. But it's not only the melting of the ice sheets that plays a role here.

[00:03:29] Also playing its part are movements taking place deep inside the Earth's interior. Deep down in the Earth's mantle, where rock becomes more viscous due to the higher pressure, displacements occur over long time periods.

[00:03:43] And there are also heat flows in the Earth's liquid metallic outer core which both generate the Earth's magnetic field and lead to shifts in mass. The study also shows that these processes both on and in the Earth appear to be interconnected, influencing each other.

[00:03:59] Climate change is causing the Earth's axis of rotation to move, and it appears that the feedback from this conservation of angular momentum is also changing the dynamics of the Earth's core. So ongoing climate change could therefore even be affecting processes deep inside the

[00:04:15] Earth, thereby having a far greater reach than previously assumed. The work was made possible because of new artificial intelligence generated algorithms which are recording all the different effects on the Earth's surface as well as those

[00:04:28] in its mantle and in its core, producing a model which takes into account all possible interactions. The results show how the Earth's rotational poles have moved since 1900. And these model values are in excellent agreement with real-life data provided by astronomical

[00:04:45] observations and satellites over the last 30 years, which means because they're so accurate they're also able to provide forecasts into the future. Soches says even if the Earth's rotation is changing only slowly, this effect still

[00:04:58] needs to be taken into account when navigating in space, such as when sending a probe to land on another planet. You see, even a slight deviation of just a centimetre on Earth can grow to a deviation

[00:05:11] of hundreds of metres, even kilometres, over the sort of huge distances involved in interplanetary travel. That means missing a targeted safe landing zone on another world for an area which may be far more hazardous, even deadly. This is Space Time.

[00:05:29] Still to come, we explain the three-body problem in celestial mechanics and a rare mid-flight failure for SpaceX's Falcon 9. All that and more still to come on Space Time. One of the most troubling mathematical conundrums that astronomers need to deal with when determining

[00:06:02] the orbits of celestial objects such as stars, planets, asteroids, even spacecraft is what's known as the three-body problem. Solving it's really hard, and the input data quickly changes as new observations and variables come to hand. Recently the three-body problems attracted the imagination of the general public thanks

[00:06:22] to the Netflix science fiction series of the same name. The title refers to the classical three-body problem in orbital mechanics relating to the motion of three celestial bodies under their mutual Newtonian gravitational attraction. It's one of many scientific problems where even a slight generalisation of a simple system

[00:06:41] results in some challenging complications. The basic two-body problem reduces to just a one-dimensional single particle movement by choosing a convenient coordinate system. The equations of motion of the reduced problem have a closed form solution.

[00:06:57] But on the other hand, for a three-body problem, only in a very few occasions can the equations of motion be reduced simply enough to obtain an analytical solution. The main plot in the Netflix series involves an alien civilization which inhabits a planet

[00:07:13] in the nearby Alpha Centauri triple star system. In their story, the planet endures extreme climate change due to the chaotic nature of the triple star system. In reality, a triple star system with chaotic properties would quickly encounter two possible outcomes, depending on the formation of the system.

[00:07:30] In one scenario, the two stars collide forming a giant single star, or in some cases a neutron star or black hole, depending on the initial mass of the two stars. The second possibility involves one of the stars being ejected from the system completely,

[00:07:44] leaving a binary star system in its place. In the case of Alpha Centauri, we have two stars, both similar in mass to the Sun, one slightly larger, the other slightly smaller, known as Alpha Centauri A and B. They orbit

[00:07:57] each other, and it's a fairly stable system, although the distance between these two stars can vary, ranging from the distance between the Sun and Saturn out to the distance between the Sun and Pluto.

[00:08:09] These two stars, Alpha Centauri A and B, are in turn orbited at a much, much, much greater distance by a third star in the same system called Proxima Centauri. But Proxima Centauri is a long way out from the binary pair in the centre, something like

[00:08:25] 340 times further out than Neptune's orbit around the Sun. Proxima Centauri also happens to be the closest star system to our own solar system, located just 4.24 light years away. In physics, specifically classical mechanics, the three-body problem involves taking the

[00:08:42] initial positions and velocities or momenta of three-point masses that orbit each other in space, and then calculating their subsequent trajectories using Newton's laws of motion and universal gravitation. Unlike the two-body problem we discussed earlier, the three-body problem has no general closed form solution.

[00:09:01] When three bodies orbit each other, the resulting dynamic or system is chaotic for most initial conditions, and the only way to predict the motions of the bodies is to calculate them using numerical methods. There is no general closed form solution to the three-body problem.

[00:09:17] So this has been a subject of great historical significance, catalyzing the development of new mathematical ideas and methods. The earliest known attempts to solve the problem started around 1687. That's when Sir Isaac Newton published his book Principia and geometrically solved the problem of two bodies.

[00:09:36] Newton tried, but without success, to describe the orbits of the moon, earth and sun using the same principles, but he soon discovered the three-body problem was somewhat more difficult. In fact, between 1750 and the beginning of the 20th century, more than 800 papers relating

[00:09:52] to the three-body problem have been published. Between 1748 and 1772, the famed mathematician Leonhard Euler studied the restricted problem in which the third body, assumed to have no mass, moves in the plane defined by the two revolving bodies. While gravitationally influenced by them, it exerts no influence of its own.

[00:10:13] Euler found a specific solution in which the three bodies stay in a line or collinear configuration and whose properties don't change over time. But that doesn't work in the real world. Then in 1772, Joseph Louis Lagrange found a particular solution where the three bodies

[00:10:29] are placed at the corners of an equilateral triangle. Studying the restricted problem, Lagrange found five unique points where the forces acting on the third body of a rotating system are balanced. These Lagrangian points, as they've become known, are important because they're stable orbits for satellites.

[00:10:48] The classical period for the three-body problem culminated with the work of Henri Poincaré, who in 1890 published a memoir on the restricted three-body problem. His work actually goes beyond the three-body problem, dealing with a qualitative theory of dynamical systems.

[00:11:04] Poincaré determined that some configurations of a triple system can be chaotic. For those systems, a tiny difference in the initial condition leads to a divergence in the orbits. The possible outcomes of chaotic systems involve the escape of one of the bodies or the collision of two of them.

[00:11:21] In a chaotic system, the three-body configuration only lasts for a handful of orbits. On the other hand, many solutions turn out to be periodically stable. In 1912, Carl Sudman thought he solved the problem mathematically by providing a convergent power series solution which was valid for all time values.

[00:11:40] However, the convergence rate of the system was so extremely slow it was pretty well useless for practical purposes. Since the 1950s, computational numerical solutions to the three-body problem have provided the best approximations we have to the solution for any given initial configuration.

[00:11:59] Numerical solutions for the n-body problem do not distinguish between two, three or more bodies because the same technique works in each case. The only difficulty arises from the fact that the computational costs increase with the inclusion of more bodies.

[00:12:12] Jacobian or hierarchical systems, such as the Alpha Centauri triple star system for example, are configurations composed of two parts. A binary, such as Alpha Centauri a and b, and a third body orbiting far away, Proxima Centauri.

[00:12:28] A subclass of periodic solutions is where every particle moves periodically in a single closed orbit, and such solutions are known as choreographic. An example of choreographic solutions is Moore's figure 8. In recent years, improvements in computational and mathematical techniques have facilitated the discovery of many more solutions.

[00:12:50] But periodic solutions can be unstable. For instance, Lagrange's solution is stable only if one of the bodies holds more than 95% of the total mass of the system. It was in 1915 when the astrophysical three-body problem underwent its most profound transformation with the publication of Einstein's General Theory of Relativity.

[00:13:11] Einstein's work marked the birth of a new three-body problem, one including new features and complexities. The relativistic three-body problem refers to the three compact objects problem only because stellar compact objects like neutron stars and black holes require a relativistic description,

[00:13:29] one that includes frame dragging and other changes to the very fabric of space-time. But it's not just astronomy. The three-body problem is actually important well beyond astrophysics. You see, on the small quantum scale of things, many molecules comprise triplets, perhaps the

[00:13:45] best known of these and maybe most important being the water molecule H2O. Unlike gravitational forces, molecular forces are repulsive at short separations and become attractive when the particles are relatively far apart. Binding molecular forces are often seen as analogous to springs for many solids.

[00:14:05] At the Australian Nuclear Science and Technology Organisation, ANSTO, scientists are performing numerical simulations on materials using the spring-like properties of molecules. Looking at even smaller scales, there's deuterium, an isotope of hydrogen which contains

[00:14:20] not just a proton but also a neutron within the nucleus, and that nucleus is then orbited by a single electron. Deuterium is naturally abundant in the form of heavy water. Due to its scattering and chemical properties, it's an essential molecule in science.

[00:14:36] It's used to study the composition of materials and has many applications in medicine, biology and chemistry. ANSTO's National Deuteration Facility provides scientists with a wide range of high-quality deuterated molecules. And we can even drill deeper than that. Protons and neutrons are another example of a triplet.

[00:14:55] See protons are composed of two up quarks and a down quark, while neutrons are composed of a single up quark and two down quarks. Quarks are elementary particles and the fundamental building blocks of matter. They combine to form particles known as hadrons.

[00:15:12] The Australian Centre for Neutron Scattering at ANSTO uses neutrons generated by the Opel atomic reactor to investigate the properties of various materials. ANSTO scientist Dr Pablo Galavis undertook his PhD on the three-body problem as it applies to black holes.

[00:15:28] Yeah, the three-body problem refers to the movement of celestial bodies. So it really generalised the first problem that was solved by Newton. So Newton was looking at, for example, the orbit of planets around the sun. And in that case you consider like a two-body problem.

[00:15:47] And the next step, once you solve the two-body problem, which is possible to solve analytically, was to look at the three-body problem, which is essentially the problem of the sun, the air and the moon, which was also very important at the time, right?

[00:16:02] To try to understand whether the moon is in a stable orbit or will eventually collapse or escape from the system. So I guess that's quite important to try to understand. And that's why Newton focused on that problem.

[00:16:16] Realising it wasn't that easy, generalisation, so after that many people tried to tackle the problem and most of them failed. Some others had a partial success. And at the moment we know some solutions for very simple cases, but the general solution

[00:16:34] is usually, you need usually a simulation or some other approximation to get accurate results. You've done a dissertation on it for your PhD. That's very brave. Yes, well there are different aspects, right? We cannot write down the equation and say this is an equation that describes every possible

[00:16:54] system, but we can write down approximations. So since the creation of the computer, we start solving the problem using numerical solutions. And what we found out that it's not only difficult to solve analytically, also from the numerical

[00:17:09] point of view it's hard to solve because they have a property that is the chaos. So the chaos manifests in the three-body problem when you have two systems pretty much with the same configuration, the same location of the celestial bodies, but you have one

[00:17:25] that is slightly shift or out of position, let's say, and then you evolve the system. What we observe in those cases is that the system will evolve completely differently. It doesn't matter how small is the change in the initial condition, eventually the system

[00:17:42] diverges in the sense that one of the bodies will, for example, escape from the system or they will collide, etc. And that manifests in each of the two different, say, snapshots in a completely different way.

[00:17:54] So that's why we say that three-body problem has some solutions that are chaotic. There are also solutions that are not chaotic and those are stable configurations and those don't have this issue. So you can have, for example, what is called a Jacobian system, which is a binary system

[00:18:12] and a system orbiting far away, just perturbing the system. For example, we can consider the Sun as the perturbing body and the Earth and the Moon as the binary system. And the Sun really doesn't affect much the Moon and the Earth system.

[00:18:28] And in that case, we get a stable configuration. So we don't have this issue of chaos. The most common example for the average listener would be when here on Earth we find out that

[00:18:39] there's an asteroid that's going to pass nearby and we've got to calculate the orbit of that in relation not just to the gravitational effect of the Earth and the Moon, but also the Sun and the other planets. That becomes really difficult.

[00:18:52] Yeah, in that case we deal with more than three bodies. We call that the un-body problem. And it's actually the state where most of the system evolves because we see, for example, the orbit of the Earth will be slightly perturbed by all the other planets, particularly the

[00:19:09] large planets. And if you want to really consider very accurate trajectories in the solar system, you need to consider most of the bodies in certain ways. One thing that we can say is once you solve the three-body problem, then it's easier to generalize.

[00:19:24] It's the same technique that we use for simulating, for example, three bodies. You can apply it to more than three bodies. And in that case, it's not as complicated. I guess the main issue is going from two to three because then the whole problem changes dramatically.

[00:19:38] What you're doing, Bud, is you're transposing that not on celestial bodies but on the subatomic world. Yeah, we can also think of different levels. So we have, for example, the celestial body, which is the original three-body problem.

[00:19:53] And there are other cases, especially any system with potential or with a force can be treated in a similar fashion. In the case of subatomic particles, the forces are completely different. We are talking about electromagnetic forces acting on the atoms and then you have also nuclear forces.

[00:20:12] So in that case, the problem is not only different in scale but it's also different in the way we describe. And for example, in the case of subatomic particles or materials in general at atomic

[00:20:25] level, the forces acting on the atoms are of a different nature because they're not only attractive, they are also repulsive forces. Mainly because we have positive and negative charges. In that regard, the dynamics of the system change completely.

[00:20:42] We can see that more clearly because we don't have this property of a chaotic system. We have most of the materials behaving in a certain manner that makes them stable. If you get very large atoms and very large nuclei, then you get unstable systems and

[00:21:00] then you have radiation. But in general, we have a stable system in the case of the atomic forces. On the celestial scale, gravity is the big thing. But on the subatomic scale, does gravity still play a role at all or is it all about the

[00:21:12] electromagnetic large and small nuclear forces? Now, day to day will be mainly electromagnetic forces. The gravitational forces are extremely weak. The only case when we need to consider something beyond or combining the two systems is for example if you have compact bodies like black holes or neutron stars.

[00:21:32] And in that case, we don't have yet a description that unifies the electromagnetic forces and the nuclear forces with the gravity. That will be the quantum gravity theory. It will be a complete theory.

[00:21:45] But we can describe, for example, the dynamics of black holes under the, for example, the three body problem under the gravitational, the strong gravitational wave fields like the black hole. And that's something you've been looking at. Yes, I did that for my PhD.

[00:22:00] That was the focus of my PhD. So looking at compact objects, in particular black holes. So what we were trying to do is simulate the collision of the black holes and also looking at the stability of the orbit of the black holes.

[00:22:15] And we wanted to know if the inclusion of gravitational waves changed anything in regard to the chaotic properties of a black hole system. And that's very important because as soon as you introduce radiation, so the gravitational

[00:22:29] wave takes energy from the system and that might mitigate some of the effects of a chaotic system. So, for example, if you don't include gravitational radiation, the bodies can either collide or escape. But if there is strong radiation, the most likely outcome is that the bodies will collapse

[00:22:50] into a single black hole. So that's how the gravitational waves can affect the dynamics of a three body system. So where do you go to from there? Is it that's when you start looking at the effects of Hawking radiation and particles popping in and out of existence?

[00:23:06] In that case, it's less important that kind of phenomenon because you are talking about the dynamic system of black holes. So you will have, for example, black holes that are already very close to a collision state.

[00:23:20] And in that case, they start radiating gravitational waves with a certain amount of radiation. So what happens is these gravitational waves are taking energy from the system and that's how the black holes end up colliding. So it's mainly through gravitational radiation that the black holes will collide.

[00:23:40] Perhaps an important problem is to find out how the black hole ends up at the distance necessary to initiate the collapse. And that's part of why people start looking at triple black holes, because this problem of having a binary system close enough is called the last perfect problem.

[00:23:59] And there is really no solution up to date to that problem. One of the ideas is that the black holes interact with each other, for example, in the center of the galaxy, in the nucleus of the galaxy, will interact with each other and through,

[00:24:13] let's say, short encounters, they start radiating some of the energy through gravitational radiation and eventually they end up close enough to collide. And for that to merge, yes. And for that it's quite important, the three-body interaction, because you might have, for example,

[00:24:31] in the center of the galaxy, you might have many black holes and they will start interacting to each other. And then you can have a binary system and a third black hole and you might have eventual collapse.

[00:24:43] Either the binary system will collide or you can even have a triple merger if the three-body is further close enough. Of course, we see a good example of the three-body problem on a celestial scale in our own solar

[00:24:56] system when all the planets are in the right position, including Jupiter, the Sun is no longer in the barycenter. Yes. Well, there are several effects. On one hand, the planets, mainly the large planets, will affect the rest of the planet.

[00:25:12] So you will have more deviations from what you would expect if you solve the, let's say, the two-body problem. And also you might have some general relativity effect. What was discovered early on by Einstein, actually, he predicted the perihelion shift

[00:25:29] of Mercury using general relativity, which is a relativistic effect. And in that case, we observe the effects of the other planets and in particular the relativistic effects as well. That's Dr Pablo Galavis from the Australian Nuclear Science and Technology Organisation, ANSTO. And this is Space Time.

[00:25:51] SpaceX's Falcon 9 rockets grounded following a rare mid-flight failure. And later in the Science Report, we look at the world's biggest ever computer outage. All that and more still to come on Space Time. SpaceX's Falcon 9 rockets being grounded by the Federal Aviation Administration after

[00:26:25] the usually highly reliable launch vehicle experienced a rare mid-flight failure. A full investigation by the FAA, the National Transportation Safety Board and SpaceX is now underway. The mission was designed to place another batch of 20 Starlink broadband internet satellites into orbit.

[00:26:43] The launch from the Vandenberg Space Force Base in California lifted off normally. The first stage performed normally throughout its mission, successfully achieving MECA or Main Engine Cut-Off and Stage Separation. It then returned to Earth for a perfect drone ship landing downrange in the Pacific Ocean.

[00:27:01] However, after performing its first engine burn successfully, the Falcon 9's upper stage experienced a liquid oxygen leak and that caused the rocket motor to explode during a planned relight needed to place the satellites in the correct orbits.

[00:27:15] Instead, they wound up being deployed into a highly eccentric orbit with a perigee or orbital low point of just 135 km, only about half of what was needed. Attempts to try and lift their orbits failed, and the spacecraft are now re-entering the

[00:27:30] Earth's atmosphere where they're expected to burn up. The rare failure comes eight years after the last Falcon 9 mishap that involved a launchpad explosion during the fueling process before a static fire test was set to occur back in September 2016.

[00:27:45] The last in-flight failure occurred over a year earlier, back in June 2015, when the second stage of another Falcon 9 exploded two and a half minutes after launch following an overpressure incident also involving a liquid oxygen tank, and that resulted in

[00:27:59] the loss of a Dragon cargo ship carrying supplies destined for the International Space Station. Interestingly, the Dragon capsule actually survived the explosion, but it was never programmed to be capable of deploying its parachutes during the ascent phase of a mission.

[00:28:14] Overall, the Falcon 9, which right now is the world's busiest rocket, has launched successfully 364 times, carrying both crews and cargo into orbit. And this failure will delay the next Dragon resupply mission to the space station, which is slated for next month.

[00:28:31] More importantly, it'll also affect the manned Polaris Dawn mission. That was to launch next week on July 31st, carrying a private crew of four astronauts on a five-day flight designed to set a new Dragon orbital apogee record of 1,400 kilometres.

[00:28:49] When it does take place, the journey will see the crew fly through parts of the Van Allen radiation belts, conducting some 38 science and research experiments designed to study the effects of spaceflight and radiation on human health.

[00:29:02] This is Space Time, and time now to take a brief look at some of the other stories making use in science this week with the Science Report. Technology experts and cyber-engineers are still sifting through the cascade of events last week which triggered the world's biggest ever computer outage.

[00:29:36] Billions of people around the world were affected by the catastrophic CrowdStrike software crash, which plunged the globe back into the 80s for several hours. The IT crash hit computers around 3 o'clock Friday afternoon AEST, shutting down some

[00:29:52] government systems as well as many businesses, stores, banks, airlines, telcos and media outlets, leaving users with the infamous blue screen of death as servers and devices became stuck in reboot loops. Governments were quickly placed into panic mode as they tried to come to grips with the ever-expanding problems.

[00:30:12] In Australia, the National Cyber Security Coordinator was able to quickly confirm that the issues weren't related to a cyber attack but rather a bad software update. The cause was Texas cyber security company CrowdStrike, which had uploaded a new version

[00:30:27] of its Falcon sensor software to their servers and to the cloud. From there it quickly spread globally, affecting Microsoft's systems. Falcon Sensor is installed on business computers and is designed to gather security data. And symptoms included hosts experiencing bug-checked blue screen errors related to the Falcon Sensor.

[00:30:48] Technicians were able to develop a workaround within hours, which we posted on our XFeed. Of course, by then the damaging confidence had been done, with the public asking quite legitimate questions about the true viability of things like a cashless society or for

[00:31:03] that matter the National Digital ID Card scheme, both of which are being heavily promoted by government. Scientists have identified more than 5,000 variants of a tumor-protecting gene that could put people at higher risk of cancer. The findings, reported in the journal Nature, could help develop new types of treatments

[00:31:22] and prevention regimes. The authors tested genetic changes in the BAP1 gene, which usually helps protect the body against various cancers by artificially altering cells in a dish. They say 5,665 of the 18,108 changes they tested harmed the gene's protective abilities.

[00:31:42] And people who have any of these changes are over 10% more likely to be diagnosed with cancer than the general population. The researchers say the new findings can help doctors diagnose and treat their patients now, but they also found that people with harmful BAP1 variants at higher levels of

[00:31:59] a specific hormone in their blood and future research should look into whether or not this hormone can be targeted for new prevention and treatment strategies. Scientists have sequenced the entire genetic makeup of the iconic Australian bilby.

[00:32:14] The findings, reported in the journal Nature, College and Evolution, will allow researchers to better understand how these rare marsupials grow and evolve. The research provides an important tool for the conservation of the threatened species. Lesser known than other marsupials, bilbies are often referred to as the Australian Easter

[00:32:32] Bunny and of ongoing cultural significance for many Aboriginal Australian communities. A new study has shown that flagrant vaccine misinformation on platforms like Facebook, Instagram and TikTok remain a serious problem, and social media giants need to do more to police it by removing those promoting it.

[00:32:53] The study also found that fact-checkers have a poor history of accurately flagging misinformation, instead corruptly pushing political viewpoints rather than scientific facts, YouTube being a prime example of this. Tim Mendham from Australian Skeptic says one of the major issues is ambiguous misinformation,

[00:33:11] which is then attached to real scientific stories and winds up slipping through unflagged.

[00:34:42] So we're saying that now with Pfizer, Pfizer did release false information about the efficacy of their vaccine but people have then grabbed that as a hook to put their own prejudices on. That's right.

[00:34:54] I mean you take one thing which is true and then add a whole layer of other things, other conspiracies or whatever on top of it. And that stuff is often not flagged by the social media, the Facebooks of the world and

[00:35:03] therefore it slips through because it seems to be accurate, it seems to be science-based. The actual message behind it is not true and unfortunately this study found that as a result, Pfizer's vaccine is 46 times more effective than these things which have the

[00:35:13] grey area, the unflagged items and the flagged items. Obviously things which have little flags saying untrue, rubbish, don't believe this would be less effective than something which is not flagged in that way and which people assume

[00:35:24] is correct but unfortunately part of the insidiousness of the pseudoscientific and anti-science movement is that they use science against itself and by misconstruing a lot of stuff, misrepresenting half-truths, false assumptions, false conclusions, that sort of stuff. They appear good, they appear accurate and they're not.

[00:35:43] Basically what they're saying is that the social media organisation should go a bit deeper into not just the overt falsehood but in the implications of those which appear to be correct. That's probably a lot harder to do because if they're masquerading as science, you're

[00:35:55] then going to weed out the actual science, reliable science from the false science. But in any case, it's obviously very effective, these things masquerading as real science which is a shame, which is a worry.

[00:36:06] Well the other problem there of course is also the social media companies and I put this in brackets, fact-checkers aren't always that good at their job. They're often pushing a particular political angle anyway. You've got to do your own background checks, that's what the bottom line is.

[00:36:20] That's part of the problem actually. We should point out actually that this survey, what it was finding was very, very small numbers. They estimate that the unflagged grey area, vaccine-sceptical content lowered vaccination rates by 2.28% and that the flagged ones, the ones that overtly stated this is wrong,

[00:36:36] lowered vaccination rates by 0.05%. So we're talking about a small proportion of the whole population but even so, 2.2%, 2.2%, 2.3% of the entire population lowers their herd immunity rate, not to make it ineffective but certainly to make it less effective.

[00:36:52] That's Tim Indom from Australian Sceptics and that's the show for now. Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts iTunes, Stitcher, Google Podcasts, Pocket Casts, Spotify, Acast, Amazon Music, Bytes.com, SoundCloud, YouTube, your favourite podcast download provider and from Spacetime with Stuart Garry.com.

[00:37:32] Spacetime's also broadcast through the National Science Foundation on Science Zone Radio and on both iHeart Radio and TuneIn Radio. And you can help to support our show by visiting the Spacetime store for a range of promotional merchandising goodies.

[00:37:46] 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 spacetimewithstuartgarry.com for full details.

[00:38:04] 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 spacetimewithstuartgarry.tumblr.com.

[00:38:20] That's all one word and that's Tumblr without the E. You can also follow us through at Stuart Garry on Twitter, at Spacetime with Stuart Garry on Instagram, through our Spacetime YouTube channel and on Facebook just go to facebook.com forward slash Spacetime with Stuart Garry.

[00:38:37] You've been listening to Spacetime with Stuart Garry. This has been another quality podcast production from Bytes.com.