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Expedition leaders say they have found several new species of octopus using a remotely operated vehicle around 3 kilometres deep near Costa Rica

A couple of years ago I wrote a series of posts (see below) showing how anyone, with a little work, can verify the main facts about the Earth, Moon, Sun and planets. This kind of “Check-It-Yourself” astronomy isn’t necessary, of course, if you trust the scientists who write science textbooks. But it’s good to know you don’t have to trust them, because you can check it on your own, without special equipment.

The ability to “do it yourself” is what makes science, as a belief system, most robust than most other belief systems, past and present. It also explains why there aren’t widely used but competing scientific doctrines that fundamentally disagree about the basics of, say, the Sun and its planets. Although science, like religion, is captured in texts and teachings that have been around for generations, one doesn’t need to have faith in those books, at least when it comes to facts about how the world works nowadays. The books may be from the past, but most of what they describe can be independently verified now. In many cases, this can be done by ordinary people without special training, as long as they have some guidance as to how to do it. The purpose of the “Check-It-Yourself-Astronomy” series is to provide that guidance.

As I showed, nothing more than pre-university geometry, trigonometry, and algebra, along with some star-gazing and a distant friend or two, is required to

• confirm that the Earth’s a spinning (almost-)sphere,
• estimate the size of the Earth and Moon and the distance between them,
• show the Sun’s larger than the Earth and much further than the Moon, and that the stars are further still,
• verify the other planets orbit the Sun and estimate their relative distances from the Sun and their orbital times,
• infer a relation between these distances and times known as Kepler’s law, and show that a similar Kepler-type law works for objects orbiting the Earth,
• infer from these laws that the same gravity that makes ordinary objects fall does so by creating an inward acceleration, one that follows Newton’s inverse square law, holding certain objects in orbit around the Earth and others in orbit around the Sun
• confirm that the Earth orbits the Sun, by invoking Kepler’s law.
  • (Incidentally, this last statement is unambiguous, despite some claims to the contrary, even in Einstein’s theory of gravity.)

However this list is missing something important. From these methods, one can only obtain the ratios of planetary sizes to each other and to the Sun’s size, and the ratios of distances between planets and the Sun. Yet I did not explain how to measure the distance from the Earth to the Sun, or the distance from the Sun to any of the other planets, or the sizes of the other planets. It’s difficult to learn these things without sophisticated equipment and extremely precise measurements; the easiest things to measure about the planets and the Sun — their locations, motions and sizes — aren’t sufficient. (I’ll explain why they’re not sufficient in my next post.)

But shouldn’t there be a way around this problem?

Just One Good Measurement

It shouldn’t be that hard, should it? If we knew any one of these distances or sizes, we could figure out all the others.

For example, in earlier posts we saw how easily one can determine that the ratio of Jupiter’s distance from the Sun to Earth’s distance from the Sun is about 5. [In this paragraph, to keep the argument simple, I use very rough numbers.] Once we learn Earth is about 100 million miles [about 150 million km] from the Sun (which also allows us to compute the Sun’s size), we just multiply this number by 5 to get Jupiter’s distance, about 500 million miles [750 million km] from Earth. That means that Jupiter is about 400 million miles [600 million km] from Earth when the two planets are closest. Then, knowing from a simple backyard telescope that when Jupiter is closest to Earth, and thus 4 times the distance to the Sun, its apparent diameter on the sky is about 1/40 of the Sun’s diameter, we learn that Jupiter’s true diameter is about 4*(1/40) = 1/10 that of the Sun. The same methods can be applied to all the other planets as well as their moons.

The distance between Jupiter and the Sun is about 5 times that of the Earth and Sun, and so, when Jupiter, Earth and the Sun lie in a line, the Jupiter-Earth distance is about 4 times the Earth-Sun distance. This knowledge, combined with the apparent sizes of Jupiter and the Sun, can be used to infer the ratio of Jupiter’s size to that of the Sun. But not one of these sizes or distances is easy to measure. (Not to scale.)

However, finding any one of these distances or sizes is challenging for you and me. A simple geometric method used by Aristarchus in classical Greek times can be used by anyone to prove that that the Sun is at least a few million miles away and thus larger than the Earth. (This in turn tells us that Jupiter is far away and that its size is comparable to or larger than Earth.) But this method does not provide a crisp measurement. It can’t distinguish between the true answer of 100 million miles and a distance of several billion or even several trillion miles.

(Note: Later pre-telescope astronomers claimed a measurement that is only a factor of 2 below the true answer. However, it is not clear to me, from what I’ve read of the historical record, if they truly measured the distance or simply bounded it from below using Artistarchus’ approach, and got lucky that their bound is not far from the real answer. Part of the problem is that estimates of uncertainties are a modern invention; the Greek authors just state a value without any recognition that this value might be wildly off [especially on the high end] simply because of the method used. If any readers have additional insight into this, please let me know. In any case, I am currently unaware of any easy and accurate check-it-yourself method that ancient astronomers could have employed.)

In the 1600s and 1700s, the distances to other nearby planets were determined using difficult parallax measurements, in which a planet was observed carefully at two distant locations (or two different times) on Earth. Modern methods often involve firing a strong radar pulse at another planet, Mars or Venus typically; the pulse reflects off that distant planet, and the arrival time of the faint echo, times the known speed of light (also known as the cosmic speed limit, 186000 miles [300000 km] per second), equals twice Earth’s distance to the planet. As I emphasized above, it only takes one such measurement to fix the distances and sizes of all the distant, large objects in the solar system. Unfortunately, none of these techniques is easily reproduced without highly precise measurements and/or fancy equipment.

Nevertheless, it turns out that there are less well-known methods that, via an indirect route, can get us a good estimate of the distance to the Sun, in ways that don’t suffer from the problems of Artistarchus’ approach. This is what I will explain over the next few posts…

In 1964 Isaac Asimov, asked to imagine the world 50 years in the future, wrote:

“The appliances of 2014 will have no electric cords, of course, for they will be powered by long- lived batteries running on radioisotopes. The isotopes will not be expensive for they will be by- products of the fission-power plants which, by 2014, will be supplying well over half the power needs of humanity.”

Today nuclear fission provides about 10% of the world’s electricity. Asimov can be forgiven for being off by such a large amount. He, as a science fiction futurist, was thinking more about the technology itself. Technology is easier to predict than things like public acceptance, irrational fear of anything nuclear, or even economics (which even economists have a hard time predicting).

But he was completely off about the notion that nuclear batteries would be running most everyday appliances and electronics. This now seems like a quaint retro-futuristic vision, something out of the Fallout franchise. Here the obstacle to widespread adoption of nuclear batteries has been primarily technological (issues of economics and public acceptance have not even come into play yet). Might Asimov’s vision still come true, just decades later than he thought? It’s theoretically possible, but there is still a major limitation that for now appears to be a deal-killer – the power output is still extremely low.

Nuclear batteries that run through thermoelectric energy production have been in use for decades by the aerospace industry. These work by converting the heat generated by the decay of nuclear isotopes into electricity. Their main advantage is that they can last a long time, so they are ideal for putting on deep space probes. These batteries are heavy and operate at high temperatures – not suitable for powering your vacuum cleaner. There are also non-thermal nuclear batteries, which do not depend on a heat gradient to generate electricity. There are different types depending on the decay particle and the mechanism for converting it into electricity. These can be small cool devices, and can function safely for commercial. In fact, for a while nuclear powered pacemakers were in common use, until lithium-ion batteries became powerful enough to replace them.

One type of non-thermal nuclear battery is betavoltaic, which is widely seen as the most likely to achieve widespread commercial use. These convert beta particles, which are the source of energy –

“…energy is converted to electricity when the beta particles inter-act with a semiconductor p–n junction to create electron–hole pairs that are drawn off as current.”

Beta particles are essentially either high energy electrons or positrons emitted during certain types of radioactive decay. They are pretty safe, as radiation goes, and are most dangerous when inhaled. From outside the skin they are less dangerous, but high exposure can cause burns. The small amounts released within a battery are unlikely to be dangerous, and the whole idea is that they are captured and converted into electricity, not radiated away from the device. A betavoltaic device is often referred to as a “battery” but are not charged or recharged with energy. When made they have a finite amount of energy that they release over time – but that time can be years or even decades.

Imagine having a betavoltaic power source in your smartphone. This “battery” never has to be charged and can last for 20-30 years. In such a scenario you might have one such battery that you transfer to subsequent phones. Such an energy source would also be ideal for medical uses, for remote applications, as backup power, and for everyday use. If they were cheap enough, I could imagine such batteries being ubiquitous in everyday electronics. Imagine if most devices were self-powered. How close are we to this future?

I wish I could say that we are close or that such a vision is inevitable, but there is a major limiting factor to betavoltaics – they have low power output. This is suitable for some applications, but not most. A recent announcement by a Chinese company,  Betavolt, reminded me of this challenge. Their press release does read like some grade A propaganda, but I tried to read between the lines.

Their battery uses nickel-63 as a power source, which decays safely into copper. The design incorporates a crystal diamond semiconductor, which is not new (nuclear diamond batteries have been in the news for years). In a device as small as a coin they can generate 100 microwatts (at 3 volts) for “50 years”. In reality the nickel-63 has a half-life of 100 years. That is a more precise way to describe its lifespan. In 100 years it will be generating half the energy it did when manufactured. So saying it has a functional life of 50 years is not unreasonable.

The problem is the 100 microwatts. A typical smart phone requires 3-5 watts of power. So the betavolt battery produces only 1/30 thousandth the energy necessary to run your smart phone. That’s four orders of magnitude. And yet, Betavolt claims they will produce a version of their battery that can produce 1 watt of power by 2025. Farther down in the article it says they plan-

“to continue to study the use of strontium 90, plethium 147 and deuterium and other isotopes to develop atomic energy batteries with higher power and a service life of 2 to 30 years.”

I suspect these two things are related. What I mean is that when it comes to powering a device with nuclear decay, the half-life is directly related to power output. If the radioisotope decays at half the rate, then it produces half the energy (given a fixed mass). There are three variables that could affect power output. One is the starting mass of the isotope that is producing the beta particles. The second is the half life of that substance. And the third is the efficiency of conversion to electricity. I doubt there are four orders of magnitude to be gained in efficiency.

From what I can find betavoltaics are getting to about the 5% efficiency range. So maybe there is one order of magnitude to gain here, if we could design a device that is 50% efficient (which seems like a massive gain). Where are the other three orders of magnitude coming from? If you use an isotope with a much shorter half-life, say 1 year instead of 100 years, there are two orders of magnitude. I just don’t see where the other one is coming from. You would need 10 such batteries to run your smart phone, and even then, in one year you are operating at half power.

Also, nuclear batteries have constant energy output. You do not draw power from them as needed, like with a lithium-ion battery. They just produce electricity at a constant (and slowly decreasing) rate. Perhaps, then, such a battery could be paired with a lithium-ion battery (or other traditional battery). The nuclear battery slowly charges the traditional battery, which operates the devices. This way the nuclear battery does not have to power the device, and can produce much less power than needed. If you use your device 10% of the time, the nuclear battery can keep it charged. Even if the nuclear battery does not produce all the energy the device needs, you would be able to go much longer between charges, and you will never be dead in the water. You could always wait and build up some charge in an emergency or when far away from any power source to recharge. So I can see a roll for betavoltaic batteries, not only in devices that use tiny amounts of power, but in consumer devices as a source of “trickle” charging.

At first this might be gimicky, and we will have to see if it provides a real-world benefit that is worth the expense. But it’s plausible. I can see it being very useful in some situations, and the real variable is how widely adopted such a technology would be.

The post Betavoltaic Batteries first appeared on NeuroLogica Blog.

Captain, the immune system is boosted, and I donno what to do.Mr. Scott. Starship Enterprise. I think he said boosted. Might be one of those bacon/beer can examples. It is flu and cold season and there are no end of suggestions that one should boost their immune system. Two million hits on the googles for the phrase ‘Boost Immune System’. Everyone from […]

The post Boosting. What To Do. first appeared on Science-Based Medicine.

A Benedictine monk is said to have built a device allowing him to see and hear historical events.

https://traffic.libsyn.com/secure/sciencesalon/mss398_Paul_Halpern_2024_01_02.mp3 Download MP3

Our books, our movies—our imaginations—are obsessed with extra dimensions, alternate timelines, and the sense that all we see might not be all there is. In short, we can’t stop thinking about the multiverse. As it turns out, physicists are similarly captivated.

In The Allure of the Multiverse, physicist Paul Halpern tells the epic story of how science became besotted with the multiverse, and the controversies that ensued. The questions that brought scientists to this point are big and deep: Is reality such that anything can happen, must happen? How does quantum mechanics “choose” the outcomes of its apparently random processes? And why is the universe habitable? Each question quickly leads to the multiverse. Drawing on centuries of disputation and deep vision, from luminaries like Nietzsche, Einstein, and the creators of the Marvel Cinematic Universe, Halpern reveals the multiplicity of multiverses that scientists have imagined to make sense of our reality. Whether we live in one of many different possible universes, or simply the only one there is, might never be certain. But Halpern shows one thing for sure: how stimulating it can be to try to find out.

Dr. Paul Halpern is the author of 18 popular science books, exploring the subjects of space, time, higher dimensions, dark energy, dark matter, exoplanets, particle physics, and cosmology. The recipient of a Guggenheim Fellowship, a Fulbright Scholarship, and an Athenaeum Literary Award, he has contributed to Nature, Physics Today, Aeon, NOVA’s “The Nature of Reality” physics blog, and Forbes “Starts with a Bang!” He has appeared on numerous radio and television shows including “Future Quest,” “Science Friday,” “Radio Times,” “Coast to Coast AM,” “The Simpsons 20th Anniversary Special,” and C-SPAN’s “BookTV.” He appeared previously on the show for his book Synchronicity: The Epic Quest to Understand the Quantum Nature of Cause and Effect. His new book, The Allure of the Multiverse, describes the controversial history of higher dimensional and parallel universe schemes in science and culture. More information can be found at: allureofthemultiverse.com

Shermer and Halpern discuss:

• universe and multiverse meaning
• Is the multiverse science, metaphysics, or faith?
• theists claim the “multiverse” is just handwaving around the God answer
• types of multiverses
• many worlds interpretation of quantum mechanics?
• inflationary cosmology and eternal inflation
• Darwinian cosmology
• infinity and eternity
• multiple dimensions and the multiverse
• string theory and the multiverse
• cyclical universes and multiverses (the Big Bounce)
• Anthropic Principle (weak, strong, participatory)
• time travel and the multiverse
• sliding doors, contingency, and the multiverse.

If you enjoy the podcast, please show your support by making a $5 or $10 monthly donation.

You think you know someone, then you see them in a slightly different way and BAM, they surprise you. I’m not talking about other people of course, I’m talking about a fabulous star that has been studied and imaged a gazillion times. Beta Pictoris has been revealed by many telescopes, even Hubble to be home to the most amazing disk. Enter James Webb Space Telescopd and WALLOP, with its increased sensitivty and instrumentation a new, exciting feature emerges. 

Beta Pictoris is the second brightest star in the southern constellation Pictor. It is a very young star, thought to be about 20 million years old and at a distance of just 63 light years, is in our cosmic backyard. Observations in 1984 revealed that Beta Pictoris had the most amazing dust disk out of which planets are forming. The European Southern Observatory has since confimred there are at least two planets (imaginitively called Beta Pictoris b and Beta Pictoris c) orbiting within the dust disk. 

Over the years, Beta Pictoris has been the target for many observations including those from the Hubble Space Telescope that revealed a second, previously unseen disk. The second disk is slightly inclined to the first but further observations from the James Webb Space Telescope (JWST) have revealed a new structure in this second disk. 

The team, led by Isabel Rebollido from the Astrobiology Center in Spain used the Near-Infrared Camera (NIRI) and the Mid-Infrared Instrument (MIRI) of the JWST to explore the disks of Beta Pictoris in more detail.  They were surprised to find a new structure at an angle to the secondary disk that was shaped like a cats tail. Despite the plethora of previous observations including those from the space busting HST, the instruments on JWST are more sensitive and have greater resolution. 

MIRI, ( Mid InfraRed Instrument ), flight instrument for the James Webb Space Telescope, JWST, during ambient temperature alignment testing in RAL Space’s clean rooms at STFC’s Rutherford Appleton Laboratory, 8th November 2010.

The “Cat’s Tail” was not the only surprise. When the MIRI data was studied, it revealed that the two disks were different temperatures revealing they were composed of different material. The secondary disk and Cat’s Tail were shown to be a higher temperature than the main disk. It’s also easy to deduce they are both made of dark material since they have not been previously observed in visible or near infra-red light but are bright under mid infra-red wavelengths. 

One of the theories to explain the higher temperature is that the material is highly porous, similar perhaps to the material found on comets and asteroids. The nature of the dust is one question that is perhaps easily addressed, something a little more challenging to answer is the nature and origin of the Cat’s Tail. 

The team explored a number of possible hypotheses that could explain the tail’s shape but failed to settle on a satisfactory model. One of their favoured theories is that the tail is the result of an event that occured within the disk around a hundred years ago! The event may have been a collision sending the dust into a trajectory that mirrors that of the impactor but then it starts to spread out to produce a curve. A contributory factor may simply be the angle of the tail from our vantage point causing the angle of the tail to seem steeper than it actualy is. 

One thing is for certain, the recent observations of Beta Pictoris have revealed some surprises of a very well loved and observed object. Further research will help us to gain a more fuller understanding of these new features but it leaves me wondering what other objects that we are familiar with still hold some surprises. 

Source : Webb discovers dusty cat’s tail in Beta Pictoris system

The post Webb Blocks the Star to See a Debris Disk Around Beta Pictoris appeared first on Universe Today.

Greater covid-19 vaccine uptake could have prevented several thousand deaths and hospitalisations in UK during a coronavirus wave in 2022

About 164 light-years away, a Hot Jupiter orbits its star so closely that it takes fewer than four days to complete an orbit. The planet is named WASP-69b, and it’s losing mass into space, stripped away by the star’s powerful energy. The planet’s lost atmosphere forms a trail that extends about 560,000 km (350,000 miles) into space.

Scientists know that stars can strip mass from planets that get too close. It’s called mass loss, and it’s driven by extreme UV (EUV) and/or X-ray energy from a star and by the stellar wind. It’s not a rare phenomenon, even though researchers don’t fully understand it.

But seeing the actual stream of gas coming from the planet is a rare opportunity to study mass loss.

Researchers have known about WASP-69b’s predicament and have predicted how much of the planet’s atmosphere is being stripped away. Previous research even identified a very small, subtle tail. But new research shows that the tail, which would stretch from Earth to well beyond the Moon in our Solar System, is much longer than previously thought.

The new research is titled “WASP-69b’s Escaping Envelope Is Confined to a Tail Extending at Least 7 Rp.” It’s published in The Astrophysical Journal. The first author is Dakotah Tyler, a doctoral student in the Department of Physics and Astronomy at UCLA.

“Work by previous groups showed that this planet was losing some of its atmosphere and suggested a subtle tail or perhaps none at all,” said first author Tyler. “However, we have now definitively detected this tail and shown it to be at least seven times longer than the planet itself.”

As we began to detect more and more exoplanets with NASA’s Kepler mission, followed by the TESS mission, something became apparent. There are gaps in the exoplanet population. The Neptunian Desert refers to the dearth of Neptune-sized planets on two to four-day orbits around their stars. The Small Planet Radius Gap refers to a dearth of exoplanets with radii between 1.5 and 2 times Earth’s radius. Scientists think that mass loss plays a role in both phenomena, and it’s unlikely that there’s a lack of exoplanets that form in the Gap and the Desert.

But the details of atmospheric loss are not well understood. WASP-69b and its extended tail of stripped gas give astronomers a rare opportunity to study it more closely.

“Studying the escaping atmospheres of highly irradiated exoplanets is critical for understanding the physical mechanisms that shape the demographics of close-in planets,” the authors write in their paper.

Previous researchers found the tail, so Tyler and his co-authors knew where to look. But Tyler and the other researchers used a much larger telescope for their observations. They used the 10-meter telescope at the Keck Observatory and its high-resolution spectrograph, NIRSPEC. They found that the stream, which is primarily hydrogen and helium, is much longer than thought.

This figure from the research illustrates some of the findings. In the left panel, T1 through 4 represent observation times with Keck. The orange circle is the star, and the black circle is WASP-69b. The right panel shows what the system would look like from the top down. Image Credit: Tyler et al. 2023.

“Over the last decade, we have learned that the majority of stars host a planet that orbits them closer than Mercury orbits our sun and that the erosion of their atmospheres plays a key role in explaining the types of planets we see today,” said co-author and UCLA professor of physics and astronomy Erik Petigura. “However, for most known exoplanets, we suspect that the period of atmospheric loss concluded long ago. The WASP-69b system is a gem because we have a rare opportunity to study atmospheric mass-loss in real-time and understand the critical physics that shape thousands of other planets.”

There are two different forces at work here. Radiation from the star and the stellar wind. Both forces work together to strip away WASP-69b’s and then shepherd it away. The tail is a direct result of how both of those forces work together.

“These comet-like tails are really valuable because they form when the escaping atmosphere of the planet rams into the stellar wind, which causes the gas to be swept back,” Petigura said. “Observing such an extended tail allows us to study these interactions in great detail.”

Neutral hydrogen is really hard to see, so the researchers measured the Helium in the tail and used it to estimate the overall mass loss from the planet. One of the reasons that previous research found a smaller tail is because the telescope they used is smaller. Larger telescopes gather more photons from whatever they’re observing. The figure below compares the current research, done with a larger telescope, with the previous observations. Both show helium light curves.

This figure from the research shows two nights of observations from CARMENES with four observations from the much larger Keck and its NIRSPEC instrument. Notice that the point-to-point scatter for CARMENES is much larger than with NIRSPEC, which has a higher signal-to-noise ratio. NIRSPEC’s better performance allowed the researchers to measure the helium more accurately. Image Credit: Dakotah et al. 2024

The researchers say that the star is losing about one Earth mass of material every 100 million years. But WASP-69b is a massive gas giant of about 0.29 Jupiter’s mass. This means that it would take an awfully long time to be reduced to nothing.

But it’ll never be reduced to nothing, according to the authors.

“At around 90 times the mass of Earth, WASP-69b has such a large reservoir of material that even losing this enormous amount of mass won’t affect it much over the course of its life. It’s in no danger of losing its entire atmosphere within the star’s lifetime,” Tyler said.

Exoplanets may also stabilize once they’ve been reduced to a specific mass. Some research shows that exoplanets with atmospheres that are double the radius of their core are the most stable and resist atmospheric loss. If the atmosphere is larger than this, then the planet is susceptible to atmospheric erosion and will eventually reach the more stable state outlined above. For planets with smaller atmospheres than this, runaway atmospheric loss is likely.

This figure is from separate research published in 2017. It shows the erosion of atmospheres as a function of time for planet models with a range of initial envelopes. Low-mass envelopes are stripped clean, while higher-mass ones are herded toward a stable state. Image Credit: Owen and Wu, 2017.

This new research is based on fairly brief observations. The authors point out that there’s likely more variability in the system that changes the mass loss rate over time. Understanding the variability is critical to understanding the mass loss in more detail.

“Repeat observations are valuable to probe any variability in the outflow properties, especially with different instruments,” they conclude.

The post A Hot Jupiter With a Comet-Like Tail appeared first on Universe Today.

The day when human beings finally set foot on Mars is rapidly approaching. Right now, NASA, the China National Space Agency (CNSA), and SpaceX have all announced plans to send astronauts to the Red Planet “by 2040”, “in 2033”, and “before 2030”, respectively. These missions will lead to the creation of long-term habitats that will enable return missions and scientific research that will investigate everything from the geological evolution of Mars to the possible existence of past (or even present) life. The opportunities this will create are mirrored only by the challenges they will entail.

One of the greatest challenges is ensuring that crews have access to water, which means that any habitats must be established near an underground source. Similarly, scientists anticipate that if there is still life on Mars today, it will likely exist in “briny patches” beneath the surface. A possible solution is to incorporate a system for large-scale water mining operations on Mars that could screen for lifeforms. The proposal, known as an Agnostic Life Finding (ALF) system, was one of thirteen concepts selected by NASA’s Innovative Advanced Concept (NIAC) program this year for Phase I development.

The concept was proposed by Steven Benner and a team from the Foundation for Applied Molecular Evolution (FfAME) in Alachua, Florida. Benner is a former professor of chemistry at Harvard University, ETH Zurich, and the University of Florida, where he was the V.T. & Louise Jackson Distinguished Professor of Chemistry. In 2005, he founded the Foundation For Applied Molecular Evolution, where he and his colleagues became the first scientists to synthesize a gene, thus giving birth to the field of synthetic biology.

As Benner and his team explained in their proposal, the ALF system is designed to simplify astrobiological studies on Mars before any crewed missions arrive. Its purpose is also to address several foregone conclusions raised at NASA’s 2019 Conference (Extant Life on Mars: What’s Next?) held in Carlsbad, New Mexico. During this conference, it was generally agreed that scientists have good reason to suspect the following about life on Mars:

• Life started on Mars using the same geo-organic chemistry that started life on Earth.
• Martian life persists today on Mars, in near-surface ice, low elevations, and caves, all with transient liquid brines, environments that today on Earth host microbial life.
• Martian life must use informational polymers (like DNA); Darwinian evolution requires these, and Darwinian evolution is the only way matter can organize to give life.
• While Martian “DNA” may differ (possibly radically) in its chemistry from Terran DNA, the “Polyelectrolyte Theory of the Gene” limits the universe of possible alien DNA structures.
• Those structures ensure that Martian DNA can be concentrated from Martian water, even if very highly diluted, and even if Martian “DNA” differs from Earth DNA.
• On Mars, as it exists today, information polymers cannot be generated without life (unlike other less reliable biosignatures such as methane), ensuring that life will not be “detected” if it is not present (the “false positive problem”).

Citing a previous study by SETI Institute senior scientist John D. Rummel and NASA Planetary Protection Officer (PPO) Catherine A. Conley, Benner and his team note that there are several fallacies when it comes to proposed efforts to search for extant evidence of Martian life. Addressing the planetary protection policy of the Committee on Space Research (COSPAR), Rummel and Conley concluded that there are four significant “shortcomings in their plans to look for evidence of life on Mars.” First, they addressed the contention that appropriate levels of spacecraft cleanliness are unaffordable.

Second, they challenged claims that there are major risks in assuming life could be identified through nucleic acid sequence comparison, especially if those sequences are obtained from a “Special Region” contaminated with Earth life. They also challenge the contention that present-day exploration by “dirty robots” is preferable to the possibility of contamination spread by future human exploration and that the potential effects of contaminating resources and environments essential to future human missions to Mars were not being addressed. Based on these considerations, Rummel and Conley concluded that scientists did not consider the detection of extant life on Mars “a high priority.”

Graphic depiction of the Agnostic Life System (ALF) to screen for introduced and alien life. Credit: Steven Benner

According to Benner and his colleagues, the purpose of this NIAC project is to change this view before the arrival of crewed missions, which will undoubtedly complicate the search for indigenous Martian life. Therefore, the plans for crewed missions in the coming decades place a very strict deadline on the search or life on Mars, but also offer an opportunity that can be exploited. In particular, Benner and his team indicate how mission proposals emphasize the need for in-situ resource utilization (ISRU), especially where near-surface water ice is concerned. As they wrote:

“Propellant (methane and oxygen) will be generated from that water and atmospheric carbon dioxide for the return trip back to Earth. That water ice will be mined on the scale of tens to hundreds of tons. Further, to maximize the likelihood of safe return of the crew to Earth, robotic operations that mine tons of near-surface water ice will be in place before the first human astronauts arrive. Thus, water mined in preparation for human arrival is correctly seen as an extremely large-scale astrobiological sample, far larger than dry cached rocks.”

The mined water ice, they claim, will contain dust deposited over time by Martian dust storms, allowing scientists to obtain information about the accessible surface of Mars. Therefore, the massive sample of water ice will enable a highly sensitive survey of the Martian surface for potential signs of life. The ALF system will allow for the extraction of genetic polymers – be they alien or the result of contamination from robotic missions. The ALF system also offers tools to conduct partial in-situ analysis of any polymers that dissociate in water (polyelectrolytes).

According to Benner, the system is called “agnostic” because of how it “exploits what synthetic biology taught us about the limited kinds of Darwinian genetic molecules.” Since it is an add-on system, including an ALF system represents a negligible burden in terms of mass and energy to any existing mining operation. Despite that, it will allow for science operations that will establish a strict lower limit on the amount of biomaterial that is accessible on the Martian surface and will do so before a human presence is established on Mars.

As Benner and his team summarized, the system will also be useful on other bodies humanity hopes to explore for signs of life (and possibly settle) someday. “[I]t will do so before Homo sapiens becomes a multiplanetary species. And “multiplanetary” is the correct term,” they wrote. “This add-on ALF system can be used on all celestial bodies where water will be mined to search for and analyze life, indigenous or introduced, Earth-like or alien. This includes Europa, Enceladus, the Moon, and exotic locales on Earth.”

Further Reading: NASA

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The latest coronavirus variant, JN.1, is more infectious, but seems to be causing less severe illness than in previous waves

One of the central factors in the evolution of galaxies is the rate at which stars form. Some galaxies are in a period of active star formation, while others have very little new stars. Very broadly, it’s thought that younger galaxies enter a period of rapid star formation before leveling off to become a mature galaxy. But a new study finds some interesting things about just when and why stars form.

The study looked at a type of galactic cluster known as Brightest Cluster Galaxies (BCGs), which are the largest and brightest galaxy clusters we can see. In this case, the team identified the 95 brightest clusters as seen from the South Pole Telescope (SPT). These galaxies are at redshifts ranging from z = 0.3 to z = 1.7, which spans the period of the Universe from 3.5 to 10 billion years ago.

That’s a good chunk of cosmic time, so you would think the data would show how star formation changed over time. At a high rate when galaxies were young and there was plenty of gas and dust around, then at a low rate after much of that raw material had been consumed. But what the team found was that within these clusters star formation was remarkably consistent across billions of years. They also found the key to when star formation occurs: entropy.

Entropy is a subtle and often misunderstood concept in physics. It is often described as the level of disorder in a system, where the entropy of a broken cup is higher than that of an unbroken cup. Since entropy always increases, you never see a cup spontaneously unbreak itself. But in reality, entropy can describe a range of things, from the flow of heat to the information required to describe a system.

A sample of galaxy clusters, with X-ray light seen in purple. Credit: X-ray: NASA/CXC/MIT/M. Calzadilla el al.; Optical: NASA/ESA/STScI; Image Processing: NASA/CXC/SAO/N. Wolk & J. Major

One of the things to keep in mind is that within a region of space, the entropy can decrease, as other areas increase. The most common example is your refrigerator. The interior of your fridge can be much cooler than the rest of your kitchen because electrical power pumps heat away from it. The same is true for life on Earth. Living things have a relatively low entropy, which is possible thanks to the energy we get from the Sun. A similar effect can occur within galaxy clusters. As gas and dust collapses on itself thanks to gravity, the entropy within can decrease. The material becomes denser and cooler over time, and thus stars can begin to form.

At first glance, this seems obvious. Of course stars can form when there is plenty of cool gas and dust around. That’s how it works. But what the team found is that there isn’t a specific temperature or density at which stars form. These factors play off each other in various ways, but the key is the overall entropy. Once the entropy within the cluster drops below a critical level, stars begin to form. They found that this critical level can be reached across billions of years, which is why star formation in all these clusters is so remarkably stable.

It’s an important result because it shows that rather than finding just how much gas and dust there is within a galaxy, or whether it’s at a sufficiently cool temperature, we only need to quantify the entropy of a galaxy. And when that entropy is just right, new stars will shine.

Reference: Calzadilla, Michael S., et al. “The SPT-Chandra BCG Spectroscopic Survey I: Evolution of the Entropy Threshold for Cooling and Feedback in Galaxy Clusters Over the Last 10 Gyr.” arXiv preprint arXiv:2311.00396 (2023).

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The multiverse may be a cool (and convenient) concept for comic books and superhero movies, but why do scientists take it seriously?

In a new book titled “The Allure of the Multiverse,” physicist Paul Halpern traces why many theorists have come to believe that longstanding scientific puzzles can be solved only if they allow for the existence of other universes outside our own — even if they have no firm evidence for such realms.

It’s easy to confuse the hypotheses with the hype, but Halpern says there’s a huge difference between the multiverse that physicists propose and the mystical realm that’s portrayed in movies like “Doctor Strange in the Multiverse of Madness.”

“Some people accuse scientists of trying to delve into science fiction if they even mention the multiverse,” Halpern says in the latest episode of the Fiction Science podcast. “But the type of science that people are doing when they talk about the multiverse is real science. It’s far-reaching science, but it’s real science. Scientists are not saying, ‘Hey, maybe we can meet another Spider-Man and attack Kingpin that way.'”

On one level, the concept of a multiverse — encompassing the paths that the universe takes as well as the roads not taken — addresses our instinct to wonder “what if” (which happens to be the title of a Marvel multiverse comic-book series). For example, what if Marty McFly’s mother missed out on meeting his father in “Back to the Future”?

“This whole idea of ‘which world is better, which world is worse’ — this is something people think about a lot, and inspires notions like the multiverse, where you imagine what would have happened if the universe developed differently, what would have happened if history was different,” Halpern says. “It’s a very popular question for us, and could well stem from our survival instincts in terms of planning.”

Multiplicity of multiverse motivations “The Allure of the Multiverse: Extra Dimensions, Other Worlds and Parallel Universes,” by Paul Halpern. (Basic Books)

For physicists, however, the multiverse isn’t a matter of wondering where they’d be if they went for an MBA rather than a Ph.D. Instead, the idea pops up in several scientific contexts. Quantum mechanics gave rise to deep questions about how the act of observation affects the reality being observed. The effort to answer those questions led some physicists to theorize that reality splits into different versions that go their separate ways, in line with what’s now known as the Many Worlds Interpretation.

On a different front, physicists have tried to reconcile the seemingly inconsistent implications of quantum mechanics and general relativity by proposing the existence of extra dimensions. These physicists say the inconsistencies can be mathematically resolved if there are, say, six or seven undetected dimensions in addition to our universe’s four-dimensional spacetime. A field of physics known as brane cosmology speculates that other realms of existence (or “branes,” short for membranes) could exist in parallel to our own realm.

And then there’s the Big Bang. To explain what they’re observing on the far frontiers of our accelerating universe, astrophysicists have proposed that the cosmos got its start in a bubble burst of inflation. Some have followed the trail even further, concluding that there’s no reason why our universe couldn’t spawn a multitude of bubble universes with different properties. (Sci-fi author Gregory Benford worked the idea into a 1998 novel titled “Cosm.”)

Where’s the evidence? Paul Halpern is a professor of physics at Saint Joseph’s University. (Image courtesy of Saint Joseph’s U. via Basic Books)

In his book — and in our podcast — Halpern traces the development of these theories, as well as efforts to track down evidence showing that a particular conception of the multiverse is correct.

Scientists have searched for traces of the multiverse at work in the temperature variations of cosmic microwave background radiation — the so-called afterglow of the Big Bang. They’ve tried to detect primordial gravitational waves that could tell them about the history of cosmic inflation. They’ve looked for signs of gravitons at the Large Hadron Collider, or small-scale variations in the force of gravity that could point to interactions with extra dimensions.

So far, these scientists have struck out. Some have even given up, after concluding that the multiverse hypothesis is an unprovable “theory of anything” and therefore shouldn’t be considered science.

Despite the strikeouts, Halpern hopes physicists will keep on swinging.

“The argument against even considering multiverse models is the lack of observational evidence,” he says. “However, there are many new tools in science that could be used to probe what happened at the beginning of our universe, right after the Big Bang.”

Fine-scale measurements of polarization patterns in the cosmic microwave background radiation could still turn up evidence of “scars” left behind by collisions with other bubble universes. There’s still a chance that gravitational-wave surveys could reveal evidence of interactions with other universes.

“And finally, there’s a burgeoning area of simulating cosmology, and looking to see what models suggest the production of other universes,” Halpern says. “That wouldn’t be experimental proof, but that would provide an important clue as to whether or not you can have our universe with what we believe is an initial state of ultra-rapid expansion called inflation.”

So, is the multiverse for real? Halpern is optimistic that scientists will eventually find ways to answer that question, even though they’ve found nothing but dead ends so far. “I look at the history of physics, and there are so many things that started with false starts,” he says.

Halpern points out that it took decades for physicists to find sufficient evidence for the existence of dark matter and dark energy, black holes and gravitational waves — long-shot efforts that led to Nobel Prizes.

“We have to be patient sometimes with theoretical physics and its predictions,” he says.

Head on over to the original version of this posting on Cosmic Log to get Paul Halpern’s reading recommendations for multiverse mavens. For still more about the multiverse, check out our previous Fiction Science interview with string theorist Brian Greene — plus a doubleheader with physicist Michio Kaku talking about “The God Equation” and “Quantum Supremacy.”

My co-host for the Fiction Science podcast is Dominica Phetteplace, an award-winning writer who is a graduate of the Clarion West Writers Workshop and currently lives in San Francisco. To learn more about Phetteplace, visit her website, DominicaPhetteplace.com.

Stay tuned for future episodes of the Fiction Science podcast via Apple,  Google,  Overcast, Spotify, Player.fm, Pocket Casts and Radio Public. If you like Fiction Science, please rate the podcast and subscribe to get alerts for future episodes.

The post Why Serious Scientists Are Mesmerized by the Multiverse appeared first on Universe Today.

The rules of statistical physics address the uncertainty about the state of a system that arises when that system interacts with its environment. But they've long missed another kind. In a new paper, researchers argue that uncertainty in the thermodynamic parameters themselves -- built into equations that govern the energetic behavior of the system -- may also influence the outcome of an experiment.

Researchers have developed a platform that combines automated experiments with AI to predict how chemicals will react with one another, which could accelerate the design process for new drugs.

Textbook models will need to be re-drawn after a team of researchers found that water molecules at the surface of salt water are organised differently than previously thought.

New findings debunk previous wisdom that solid-state qubits need to be super dilute in an ultra-clean material to achieve long lifetimes. Instead, cram lots of rare-earth ions into a crystal and some will form pairs that act as highly coherent qubits, a new paper shows.

New findings debunk previous wisdom that solid-state qubits need to be super dilute in an ultra-clean material to achieve long lifetimes. Instead, cram lots of rare-earth ions into a crystal and some will form pairs that act as highly coherent qubits, a new paper shows.

New research has cracked a vital process in the creation of a unique rock type from the Moon. The discovery explains its signature composition and very presence on the lunar surface at all, unraveling a mystery which has long-eluded scientists.