Today’s Jesus and Mo strip, called “Trump“, came with a short summary: “God wants you to stop projecting your own desires onto him.”
Clearly Mo is a Democrat! But of course, anybody who wishes that Trump had been killed is morally off the rails, though I’ve heard that from a few people.
Rehabilitation robots, first introduced in the 1990s, are just what they sound like – robotics used to aid in regaining function through rehabilitation following an injury. The idea sounds compelling, and the technology has been advancing steadily. But still we have to ask ourselves the question – do they actually help, and what is the evidence? A recent comprehensive meta-analysis and systematic […]
The post The Evidence for Rehabilitation Robots first appeared on Science-Based Medicine.Think about background radiation and most people immediately think of the cosmic background radiation and stories of pigeon excrement during its discovery. That’s for another day though. Turns out that the universe has several background radiations, such as infrared and even gravitational wave backgrounds. NASA’s New Horizons is far enough out of the Solar System now that it’s in the perfect place to measure the cosmic optical background (COB). Most of this light comes from the stars in galaxies, but astronomers have always wondered if there are other sources of light filling our night sky. New Horizons has an answer. No!
Ok lets talk pigeon excrement. Back in 1965 two telecommunication engineers were exploring signal interference at the Bell Laboratory. Penzias and Wilson detected a faint ‘hum’ in all directions and initially put it down to pigeon excrement as they nested in the horn of the radio receiver. Instead, what they had discovered was the cosmic background radiation, the faint glow that permeates the entire universe and is the thermal radiation left over from the Big Bang. Studying it allows us to understand more about the Universe when it was 380,000 years old.
The full-sky image of the temperature fluctuations (shown as color differences) in the cosmic microwave background, made from nine years of WMAP observations. These are the seeds of galaxies, from a time when the universe was under 400,000 years old. Credit: NASA/WMAPIn the late 80’s a different type of background radiation was detected; the infrared background radiation. It consists of the diffuse infrared glow that fills the universe coming from numerous sources throughout the history of the universe. It is mostly from thermal emissions from dust grains heated by stellar radiation. In addition to this is the gravity wave background although this has yet to be detected.
Another hotly debated background is the cosmic optical background (COB), a diffuse light which originates from stars and galaxies and spans the whole of the visible spectrum. There has been gathering momentum in its study however with observations from Hubble Space Telescope and the Spitzer Infrared Telescope. The studies however revealed that a large contribution to a general background optical glow come from faint unresolved galaxies. The study of the COB allows us to explore the total energy output of the universe, about galaxy and star formation across the history of the cosmos.
The detection of the COB is a challenging one however with Earth based instruments or even those in Earth orbit plagued by interference. The zodiacal light for example is the result of sunlight scattered by interplanetary dust, it is dominant in the inner solar system and makes studies of the COB difficult. The New Horizon probe is ideally positioned out beyond the orbit of Pluto over 8 billion kilometres away from interference. On board New Horizons is the LORRI (Long Range Reconnaissance Imager) camera which was identified as an ideal platform to begin a search.
The New Horizons instrument payload that is currently doing planetary science, heliospheric measurements, and astrophysical observations. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research InstituteUsing images from the LORRI camera, a team of astronomers led by Marc Postman from the Space Telescope Science Institute attempted to measure the COB over the range 0.4 to 0.9 micrometers. The images were from high galactic latitudes to ensure no diffuse light from the Milky Way or scattered light from bright stars. Isolating the COB contribution to the total sky brightness levels required digitally subtracting the scattered light from bright stars and galaxies and from faint stars within the field that were fainter than that detectable by LORRI. Interestingly, the results showed that, based on the estimated galaxy counts in the sampled regions the COB is the result of light from all the galaxies within our observable region of the universe.
Source : New Synoptic Observations of the Cosmic Optical Background with New Horizons
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The prospect of actually resolving the event horizon of black holes feels like the stuff of science fiction yet it is a reality. Already the Event Horizon Telescope (EHT) has resolved the horizon of the black holes at the centre of the Milky Way and M87. A team of astronomers are now looking to the next generation of the EHT which will work at multiple frequencies with more telescopes than EHT. A new paper suggests it may even be possible to capture the ring where light goes into orbit around the black hole at the centre of the Milky Way.
Black holes are strange objects that are the powerhouses of many galactic phenomenon. They have a complex anatomy with a singularity at the centre, a point of infinite density where gravity is so intense that the laws of physics cease to work. Surrounding the singularity is the event horizon, the boundary beyond which, nothing, not even light can escape. Just outside the event horizon is the photon ring and it is here that light is bent into a circular orbit around the singularity. Further out than this is the accretion disk but the focus of the next generation Event Horizon Telescope will be the photon ring.
The Event Horizon Telescope name is a little misleading for it is not one telescope but a global network of radio telescopes that work together to act as a virtual Earth-sized radio telescope. The technology that makes this happen is known as interferometry where the telescopes are all connected together. The very long baseline of the telescope or put more simply the fact it is virtually VERY big means it has incredible resolution capabilities allowing it to capture the event horizon around Sagittarius A at the centre of the Milky Way and also of the black hole at centre of M87.
The ALMA array in Chile. Once ALMA was added to the Event Horizon Telescope, it increased the EHT’s power by a factor of 10. Image: ALMA (ESO/NAOJ/NRAO), O. DessibourgThe EHT was launched in 2009 but now attention is turning to the next generation. The addition of ten new dishes and a whole host of new technology will transform EHT. Modern high-speed data transfer protocols will speed up transfer times and the addition of new dishes and technology will mean EHT will be able to observe at 86, 230 and 345 GHz simultaneously. This allows for the utilisation of frequency phase transfer techniques where lower frequency data can be used to supplement higher frequency. Using this will mean integration times of minutes at 345 GHz rather than seconds opening up a whole universe of new observations such as, the photon rings of black holes.
Studies of the supermassive black hole at the centre of M87 and Sagittarius A suggest a magnetically arrested accretion disk. In this accretion model, the accretion disk forms a series of irregular spiral streams and a vertical magnetic field, which is split into separate field lines, pokes through the accretion plane. As the disk rotates the material spirals inward, dragging the field lines and twist them around the axis of rotation leading to the formation of jets. These magnetically arrested disks exhibit symmetrically polarised synchrotron emissions which were used by a team of astronomers to study the detectability of the photon ring using next generation EHT.
M87 and the jet streaming away from its central supermassive black hole. Credits: NASA, ESA and the Hubble Heritage Team (STScI/AURA); Acknowledgment: P. Cote (Herzberg Institute of Astrophysics) and E. Baltz (Stanford University)The paper authored by Kaitlyn M. Shavelle and Daniel C. M. Palumbo from the Princeton University and Harvard & Smithsonian (respectively) show through simulations that the planned enhancements to the EHT are likely to enable the detection of photon rings. In the analyses of the enhancements they find that the higher sensitivity of the new EHT will likely be more critical than better processing techniques in the detection of the photon ring.
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The field of extrasolar planet studies has grown exponentially in the past twenty years. Thanks to missions like Kepler, the Transiting Exoplanet Survey Satellite (TESS), and other dedicated observatories, astronomers have confirmed 5,690 exoplanets in 4,243 star systems. With so many planets and systems available for study, scientists have been forced to reconsider many previously-held notions about planet formation and evolution and what conditions are necessary for life. In the latter case, scientists have been rethinking the concept of the Circumsolar Habitable Zone (CHZ).
By definition, a CHZ is the region around a star where an orbiting planet would be warm enough to maintain liquid water on its surface. As stars evolve with time, their radiance and heat will increase or decrease depending on their mass, altering the boundaries of the CHZ. In a recent study, a team of astronomers from the Italian National Institute of Astrophysics (INAF) considered how the evolution of stars affects their ultraviolet emissions. Since UV light seems important for the emergence of life as we know it, they considered how the evolution of a star’s Ultraviolet Habitable Zone (UHZ) and its CHZ could be intertwined.
The research team was led by Riccardo Spinelli, an INAF researcher from the Palermo Astronomical Observatory. He was joined by astronomers from the National Institute of Nuclear Physics (INFN), the University of Insubria, and the Astronomical Observatory of Brera. Their paper, “The time evolution of the ultraviolet habitable zone,” recently appeared in the Monthly Notices of the Royal Astronomical Society: Letters.
This infographic compares the orbit of the planet around Proxima Centauri (Proxima b) with the same region of the Solar System. Credit: ESOAs Spinelli told Universe Today via email, the UHZ is the annular region around a star where a planet receives enough UV radiation to trigger the formation of RNA precursors but not so much that it destroys biomolecules. “This zone primarily depends on the star’s UV luminosity, which decreases over time,” he said. “As a result, the UV habitable zone is farther from the star during the early stages of the star’s evolution and gradually moves closer to the star as time progresses.”
As astronomers have known for some time, CHZs are also subject to evolution, owing to changes in the star’s luminosity and heat output, which increase or decrease over time depending on the mass of the star. Addressing the interaction of these two habitable zones could shed light on which exoplanets are most likely to be “potentially habitable” for life as we know it. As Spinelli explained:
“We still do not know precisely how life originated on Earth, but we have some clues suggesting that ultraviolet (UV) radiation may have played a crucial role. Experimental studies, such as the one conducted by Paul Rimmer and John Sutherland in 2018, provide significant insights. In their experiment, Rimmer and Sutherland exposed hydrogen cyanide and hydrogen sulfite ions in water to UV light and discovered that this exposure efficiently triggered the formation of RNA precursors.
“Without UV light, the same mixture resulted in an inert compound that could not form the building blocks of life. Furthermore, RNA demonstrates a resistance to damage from UV radiation, indicating that it likely formed in a UV-rich environment. Indeed, UV radiation was one of the most abundant sources of chemical-free energy on the surface of the early Earth, suggesting it might have played a crucial role in the emergence of life.”
For their purposes, Spinelli and his colleagues sought to determine if (and for how long) the CHZ and the UVZ would overlap – thus facilitating the emergence of life. To this end, the team analyzed data from NASA’s Swift Ultraviolet/Optical Telescope (UVOT) to measure the current UV luminosity of stars with exoplanets that reside in the “classical” HZ. They then consulted data from NASA’s Galaxy Evolution Explorer (GALEX), an orbiting space telescope that has been observing galaxies up to 10 billion years away in the UV wavelength.
Illustration of the Trappist-1 system. Credit: NASA/JPL-CaltechFrom GALEX, they incorporated how moving groups of young stars evolve in terms of their near-UV luminosity. “To estimate the evolution in time of the ultraviolet habitable zone, we used the results obtained by Richey-Yowell et al. 2023,” said Spinelli. “In this work, the authors derived an average UV luminosity evolution for each type of star. In our work, we reconstructed the evolution of the UV brightness of stars hosting planets in the classical habitable zone by combining the average evolution derived by Richey-Yowell et al. 2023 and the measurements carried out with the Swift Telescope.”
From this, they determined there is an overlap between the evolution of CHZs and UHZs. These results were especially significant for M-type (red dwarf) stars, where many rocky planets have been found orbiting within their CHZs. Previous research, which includes a 2023 paper by Spinelli and many of the same colleagues, has suggested that M-dwarf stars are not currently receiving near-UV radiation to support the prebiotic chemistry necessary for the emergence of life. However, their conclusions in this latest paper contradicted their previous findings. Said Spinelli:
“We assert that, when examining the evolution of NUV luminosity in M-dwarfs, most of these cool stars are indeed capable of emitting an appropriate amount of NUV photons during the first 1–2 billion yr of their lifetimes to trigger the formation of important building blocks of life. Our results suggest that the conditions for the onset of life (according to the specific prebiotic pathway we consider) may be or may have been common in the Galaxy. Indeed, in this work, we demonstrated that an intersection between the classical habitable zone and the ultraviolet habitable zone could exist (or could have existed) around all stars of our sample at different stages of their life, with the exceptions of the coolest M-dwarfs (temperature less than 2800 K, notably Trappist-1 and Teegarden’s star).”
While they may be a bit of a letdown for those hoping to find life on some of TRAPPIST-1s seven rocky planets, it bodes well for other M-type stars hosting rocky planets in their HZs. This includes the closest exoplanet to the Solar System (Proxima b), Ross 128 b, Luyten b, Gliese 667 Cc, and Gliese 180 b, all of which are within 40 light-years of Earth. These findings could have significant implications for exoplanet and astrobiology studies, which have been transitioning from discovery to characterization in recent years.
These fields will benefit from next-generation telescopes like Webb, the Nancy Grace Roman Space Telescope, and ground-based observatories that will enable Direct Imaging studies of exoplanets.
Further Reading: MNRAS
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On May 30th, the Mars Curiosity rover was just minding its own business exploring Gediz Vallis when it ran over a rock. Its wheel cracked the rock and voila! Pure elemental sulfur spilled out. The rover took a picture of the broken rock about a week later, marking the first time sulfur has been found in a pure form on Mars.
After Curiosity’s encounter with the broken rock and its pure sulfur innards, the rover trundled over to another rock, called “Mammoth Lakes” for a little drilling session. Before it left to explore other rocks, the rover managed to cut into that rock and take samples for further study to find out its chemical composition.
It’s not that sulfur isn’t prevalent on Mars. It is, but in different forms. The stuff is highly abundant in the Solar System, so this find isn’t as surprising as you’d think. However, Curiosity finding pure sulfur in the middle of broken rocks is a new experience in Mars exploration. So, of course, that’s raising questions about how it got there and its implications for habitable environments in Mars’s long history.
Curiosity’s PeregrinationsAt the moment, the Curiosity rover is making its way through the Gediz Vallis. That’s a flow channel winding its way down a section of Mount Sharp (aka Aeolis Mons). That’s the central peak of Gale Crater. The rover has been heading up since 2014, charting different surface layers as it goes. Each layer was put down during a different era of Mars’s history. They could contain clues to the planet’s habitability in the past.
NASA’s Curiosity Mars rover captured this view of Gediz Vallis channel on March 31. Floods of water and debris piled rocks and sand into mounds within the channel. The rock the rover broke lies in a channel in this region.Fast-moving liquid water raged over the surface and carved Gediz. The floods carried a lot of rocks and sand and deposited them all along the way. Other piles of flood debris lie around the region, bearing witness to other ancient floods and landslides. “This was not a quiet period on Mars,” said Becky Williams, a scientist with the Planetary Science Institute in Tucson, Arizona, and the deputy principal investigator of the Mast Camera, or Mastcam on Curiosity. “There was an exciting amount of activity here. We’re looking at multiple flows down the channel, including energetic floods and boulder-rich flows.”
Understanding Sulfur’s PresenceThe surface materials in Gediz contain high amounts of sulfates. Those are sulfur-bearing salts that appear as water evaporates. They are a chemical clue that water existed in the region. Judging by some parts of the surface, it also appears the water ponded at some times, in addition to the floods that scoured the landscape and then deposited debris.
Now the planetary science team has to explain how a pure form of elemental sulfur got stuck in the middle of rocks, according to project scientist Ashwin Vasavada. “Finding a field of stones made of pure sulfur is like finding an oasis in the desert,” said Vasavada. “It shouldn’t be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting.”
Putting Sulfur in ContextSulfur, of course, exists on Earth, which helps scientists understand its behavior and the environments where it’s found. The presence of sulfur can be a result of various geological processes. The sulfur “cycle” includes the flow of sulfur from the core to the surface through volcanism. That’s not unusual. Sulfur commonly appears around volcanic vents. Mt Ijen in Indonesia is a good example. It sports extensive elemental sulfur deposits that are mined.
Traditional sulfur mining at Ijen. Candra Firmansyah. CC BU-SA 4.0.The volcanic moon Io in the Jupiter system features patches of different allotropes of sulfur. They’re also volcanic in origin, spewed out along with widespread lava flows. This moon has more than 400 volcanic features, making it the most volcanically active (and sulfurous) place in the Solar System.
The Jovian moon Io is seen by the New Horizons spacecraft. The mission’s camera caught a view of one of this moon’s volcanos erupting. The region that Curiosity is investigating shows evidence of different kinds of sulfur-bearing minerals. Courtesy: NASA Goddard Space Flight Center Scientific Visualization Studio.The pure sulfur in the Mars rock most likely came from volcanic processes. They occurred sometime in the past, but that doesn’t answer how the crystals got inside the rock it crushed. Scientists have known for years that Mars was extremely volcanically active in the past. For a long time, they also thought it was dead, or at least dormant. The planet has no plate tectonics like we see on Earth, either. However, the Mars InSight mission found evidence of some seismic activity on the planet in 2021.
In 2023, planetary scientists at the University of Arizona offered up evidence of a giant mantle plume under Elysium Planitia that drove some kinds of activity in the more recent past. Gale Crater lies in this region and could well have experienced related volcanic and seismic activity during the recent geologic past. If so, that could help explain the presence not only of pure sulfur but also the flood-related sulfates deposited on the surface.
For More InformationNASA’s Curiosity Rover Discovers a Surprise in a Martian Rock
Recent Volcanism on Mars Reveals a Planet More Active than Previously Thought
Sulfur on Mars from the Atmosphere to the Core
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Often times the answer to a binary question is “yes”. Is artificial intelligence (AI) a powerful and quickly advancing tool or is it overhyped? Yes. Are opiates useful medicines or dangerous drugs? Yes. Is Elon Musk a technological visionary or an eccentric opportunist? This is because the world is usually more complex and nuanced than our false dichotomy or false choice simplistic thinking. People and things can contain disparate and seemingly contradictory traits – they can be two things at the same time.
This was therefore my immediate reaction to the question – are AI companions a potentially healthy and useful phenomenon, or are they weird and harmful? First let me address a core neuropsychological question underlying this issue – how effective are chatbot companions, for just companionship, or for counseling, or even as romantic partners? The bottom line is that the research consistently shows that they are very effective.
This is likely a consequence of how human brains are typically wired to function. Neurologically speaking, we do not distinguish between something that acts alive and something that is alive. Our brains have a category for things out there in the world that psychologists term “agents”, things that are acting on their own volition. There is a separate category for everything else, inanimate objects. There are literally different pathways in the brain for dealing with these two categories, agents and non-agents. Our brains also tend to overall the agent category, and really only require that things move in a way that suggest agency (moving in a non-inertial frame, for example). Perhaps this makes evolutionary sense. We need to know, adaptively, what things out there might be acting on their own agenda. Does that thing over there want to eat me, or is it just a branch blowing in the wind.
Humans are also intensely social animals, and a large part of our brains are dedicated to social functions. Again, we tend to overcall what is a social agent in our world. We easily attribute emotion to cartoons, or inanimate objects that seem to be expressing emotions. Now that we have technology that can essentially fake human agency and emotion, this can hack into our evolved algorithms which never had to make a distinction between real and fake agents.
In short, if something acts like a person, we treat it like a person. This extends to our pets as well. So – do AI chatbots act like a real person? Sure, and they are getting better at it fast. It doesn’t matter if we consciously know the entity we are chatting with is an AI, that knowledge does not alter the pathways in our brain. We still process the conversation like a social interaction. What’s the potential good and bad here?
Let’s start with the good. We already have research showing that AI chatbots can be effective at providing some basic counseling. They have many potential advantages. They are good listeners, and are infinitely patient and attentive. They can adapt to the questions, personality, and style of the person they are chatting with, and remember prior information. They are good at reflecting, which is a basic component of therapy. People feel like they form a therapeutic alliance with these chatbots. They can also provide a judgement-free and completely private environment in which people can reflect on whatever issues they are dealing with. They can provide positive affirmation, while also challenging the person to confront important issues. At least these can provide a first line of defense, cheaply and readily available.
Therapeutic relationships easily morph into personal or even romantic ones, in fact this is always a very real risk for human counselors (a process called transferance). So, why wouldn’t this also happen with AI therapists, and in fact can be programmed to happen (a feature rather than a bug). All the advantages carry over – AI romantic partners can adapt to your personality, and have all the qualities you may want in a partner. They provide companionship that can lessen loneliness and be fulfilling in many ways. l
What about the sexual component? Indicators so far are that this can be very fulfilling as well. I am not saying that anything is a real replacement for a mutually consenting physical relationship with another person. But as a second choice, it can have value. The most important sex organ, as they say, is the brain. We respond to erotic stimuli and imagery, and sex chatting can be exciting and even fulfilling to some degree. This likely varies from person to person, as does the ability to fantasize, but for some sexual encounters happening entirely in the mind can be intense. I will leave for another day what happens when we pair AI with robotics, and for now limit the discussion to AI alone. The in-between case is like Blade Runner 2049, where an AI girlfriend was paired with a hologram. We don’t have this tech today, but AI can be paired with pictures and animation.
What is the potential downside? That depends on how these apps are used. As a supplement to the full range of normal human interactions, there is likely little downside. It just extends our experience. But there are at least two potential types of problems here – dependence on AI relationships getting in the way of human relationships, and nurturing our worst instincts rather than developing relationship skills.
The first issue mainly applies to people who may find social relationship difficult for various reasons (but could apply to most people to some extent). AI companions may be an easy solution, but the fear is that it would reduce the incentive to work on whatever issues make human relationships difficult, and reduce the motivation to do the hard work of finding and building relationships. We may choose the easy path, especially as functionality improves, rather than doing the hard work.
But the second issue, to me, is the bigger threat. AI companions can become like cheesecake – optimized to appeal to our desires, rather than being good for us. While there will likely be “health food” AI options developed, market forces will likely favor the “junk food” variety. AI companions, for example, may cater to our desires and our egos, make no demands on us, have no issues of their own we would need to deal with, and would essentially give everything and take nothing. In short, they could spoil us for real human relationships. How long will it be before some frustrated person shouts in the middle of an argument, “why aren’t you more like my AI girlfriend/boyfriend?” This means we may not have to build the skills necessary to be in a successful relationship, which often requires that we give a lot of ourselves, think of other people, put the needs of others above our own, compromise, and work out some of our issues. ]
This concept is not new. The 1974 movie, based on the 1972 book, The Stepford Wives, deals with a small Connecticut town where the men all replace their wives with robot replicas that are perfectly subservient. This has become a popular sci-fi theme, as it touches, I think, on this basic concept of having a relationship that is 100% about you and not having to do all the hard work of thinking about the needs of the other person.
The concern goes beyond the “Stepford Wife” manifestation – what if chatbot companions could either be exploited, or even are deliberately optimized, to cater to – darker – impulses? What are the implications of being in a relationship with an AI child, or slave? Would it be OK to be abusive to your AI companion? What if they “liked” it? Do they get a safe word? Would this provide a safe outlet for people with dark impulses, or nurture those impulses (preliminary evidence suggests it may be the latter). Would this be analogous to roleplaying, which can be useful in therapy but also can have risks?
In the end, whether or not AI companions are a net positive or negative depends upon how they are developed and used, and I suspect we will see the entire spectrum from very good and useful to creepy and harmful. Either way, they are now a part of our world.
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