Science

New research shows the early lunar crust which makes up the surface of the Moon was considerably enriched in water more than 4 billion years ago, counter to previously held understanding.

Researchers have simplified the operation of an important class of chemical transformation: synthesis of beta-lactams, the intricate scaffold of many antibiotics. Their experimental protocol minimizes the toxicity that is a common feature of similar Fischer-carbene synthetic methodologies, and was used to synthesize the scaffold of the thienamycin antibiotic in high yield. This work is an important advancement in sustainable chemistry that should benefit drug development and other chemical syntheses.

Researchers have helped minimize the cost of an important class of chemical transformations: converting nitriles into primary amines. Their experimental protocol uses a cheap nickel catalyst instead of an expensive noble metal, is convenient to conduct, and works for a broad range of starting materials. This work is an important advance in sustainable chemistry that might help lower the cost of producing nylon and many other everyday products.

RNA is thought to have sparked the origin of life by self-copying. Researchers have now revealed the atomic structure of an 'RNA copy machine' through cryo-EM. This breakthrough sheds light on a primordial RNA world and fuels advancements in RNA nanotechnology and medicine.

Researchers have improved the efficiency of heat-to-electricity conversion in gallium arsenide semiconductor microstructures. By judicious spatial alignment of electrons within a two-dimensional electron gas system with multiple subbands, one can substantially enhance the power factor compared with previous iterations of analogous systems. This work is an important advance in modern thermoelectric technology and will benefit the global integration of the Internet of Things.

Researchers have improved the efficiency of heat-to-electricity conversion in gallium arsenide semiconductor microstructures. By judicious spatial alignment of electrons within a two-dimensional electron gas system with multiple subbands, one can substantially enhance the power factor compared with previous iterations of analogous systems. This work is an important advance in modern thermoelectric technology and will benefit the global integration of the Internet of Things.

Neuroscientists have investigated whether playing violent video games leads to a reduction in human empathy. To do this, they had adult test subjects play a violent video game repeatedly over the course of an experiment lasting several weeks. Before and after, their empathic responses to the pain of another person were measured. It was found that the violent video game had no discernible effect on empathy and underlying brain activity.

A new experiment could in principle test the quantumness of an object regardless of its mass or energy.

Traders could have earned a threefold return on their investments by analysing trends in cryptocurrency forums on Reddit

The salt we spread to keep roads safe in winter is damaging ecosystems and threatening water supplies. Do alternatives, from coffee grounds to cheese brine, work?

A healthy rhesus monkey has been born after being cloned from fetal cells, but creating a clone of an adult human being would be much harder

With sperm counts falling around the world, researchers are finally getting to grips with the underlying causes - and coming up with ways to reverse the trend

Sperm counts are down worldwide, but researchers are finally getting to grips with why - and coming up with ways to reverse the trend

From The Matrix to Sliding Doors via Everything Everywhere All at Once, physicist Paul Halpern reveals his favourite films about the multiverse

Soil samples from a long-running UK experiment show that microplastic pollution has risen sharply in the past 50 years and is much higher in fields treated with organic or inorganic fertilisers

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…

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.

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