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Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 1:38pm

Debunking Fake Banana Hack Viral Videos

Debunking YouTube video myths and dis- and misinformation using bananas

Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 7:08am

The aurorae at Earth and Jupiter are different. Yet, it is a big surprise that they can be explained by a unified framework.

By advancing our fundamental understanding of how planetary magnetic fields interact with the solar wind to drive auroral displays, this research has important practical applications for monitoring, predicting, and exploring the magnetic environments of the solar system.

This study also represents a significant milestone in understanding auroral patterns across planets that deepen our knowledge of diverse planetary space environments, paving the way for future research into the mesmerizing celestial light shows that continue to capture our imagination.

B. Zhang et al, A unified framework for global auroral morphologies of different planets, Nature Astronomy (2024). DOI: 10.1038/s41550-024-02270-3

Part 2

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Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 7:07am

Scientists report unified framework for diverse aurorae across planets

The awe-inspiring aurorae seen on Earth, known as the Northern and Southern Lights, have been a source of fascination for centuries. Between May 10 and 12, 2024, the most powerful aurora event in 21 years reminded us of the stunning beauty of these celestial light shows.

Recently, space physicists have published a paper in Nature Astronomy that explores the fundamental laws governing the diverse aurorae observed across planets, such as Earth, Jupiter and Saturn.

This work provides new insights into the interactions between planetary magnetic fields and solar wind, updating the textbook picture of giant planetary magnetospheres. Their findings can improve space weather forecasting, guide future planetary exploration, and inspire further comparative studies of magnetospheric environments.

Earth, Saturn and Jupiter all generate their own dipole-like magnetic field, resulting in funnel-canopy-shaped magnetic geometry that leads the space's energetic electrons to precipitate into polar regions and cause polar auroral emissions.

Yet the three planets differ in many aspects, including their magnetic strength, rotating speed, solar wind condition, moon activities, etc. It is unclear how these different conditions are related to the different auroral structures that have been observed on those planets for decades.

Using three-dimensional magnetohydrodynamics calculations, which model the coupled dynamics of electrically conducting fluids and electromagnetic fields, the research team assessed the relative importance of these conditions in controlling the main auroral morphology of a planet.

Combining solar wind conditions and planetary rotation, they defined a new parameter that controls the main auroral structure, which for the first time, nicely explains the different auroral structures observed at Earth, Saturn and Jupiter.

Stellar winds' interaction with planetary magnetic fields is a fundamental process in the universe. The research can be applied to grasp the space environments of Uranus, Neptune, and even exoplanets.

This  study has revealed the complex interplay between solar wind and planetary rotation, providing a deeper understanding of aurorae across different planets. These findings will not only enhance our knowledge of the aurorae in our solar system but also potentially extend to the study of aurorae in exoplanetary systems.

Part 1

Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 6:35am

A significant problem is that our solar system only contains about 100 Earths worth of solid material, so our advanced alien civilization would need to dismantle all the planets in 10,000 planetary systems and transport it to the star to build their Dyson sphere. To do it with the material available in a single system, each part of the megastructure could only be one meter thick.

This is assuming they use all the elements available in a planetary system. If they needed, say, lots of carbon to make their structures, then we're looking at dismantling millions of planetary systems to get hold of it. Now, I'm not saying a super-advanced alien civilization couldn't do this, but it is one hell of a job.

I'd also strongly suspect that by the time a civilization got to the point of having the ability to build a Dyson sphere, they'd have a better way of getting the power than using a star, if they really needed it (I have no idea how, but they are a super-advanced civilization).

Maybe I'm wrong, but it can't hurt to look.

Matías Suazo et al, Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae1186

https://phys.org/news/2024-05-dyson-spheres-astronomers-potential-c...

Part 4

By  Simon Goodwin

Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 6:33am

However, our global energy use has started to grow much more slowly over the past 50 years, and especially over the last decade. What's more, Dyson and Kardashev never specified what these vast levels of power would be used for, they just (fairly reasonably) assumed they'd be needed to do whatever it is that advanced alien civilizations do.

But, as we now look ahead to future technologies we see efficiency, miniaturization and nanotechnologies promise vastly lower power use (the performance per watt of pretty much all technologies is constantly improving).

A quick calculation reveals that, if we wanted to collect 10% of the sun's energy at the distance the Earth is from the sun, we'd need a surface area equal to 1 billion Earths. And if we had a super-advanced technology that could make the megastructure only 10km thick, that'd mean we'd need about a million Earths worth of material to build them from.
Part3

Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 6:33am

Unfortunately, such light can also be a signature of a lot of other things, such as a disk of gas and dust, or disks of comets and other debris. But the seven promising candidates aren't obviously due to a disk, as they weren't good fits to disk models.

It is worth noting there is another signature of Dyson sphere: that visible light from the star dips as the megastructure passes in front of it. Such a signature has been found before. There was a lot of excitement about Tabby's star, or Kic 8462852, which showed many really unusual dips in its light that could be due to an alien megastructure.

It almost certainly isn't an alien megastructure. A variety of natural explanations have been proposed, such as clouds of comets passing through a dust cloud. But it is an odd observation. An obvious follow up on the seven candidates would be to look for this signature as well.
The case against Dyson spheres
Dyson spheres may well not even exist, however. I think they are unlikely to be there. That's not to say they couldn't exist, rather that any civilization capable of building them would probably not need to (unless it was some mega art project).

Dyson's reasoning for considering such megastructures assumed that advanced civilizations would have vast power requirements. Around the same time, astronomer Nikolai Kardashev proposed a scale on which to rate the advancement of civilizations, which was based almost entirely on their power consumption.

In the 1960s, this sort of made sense. Looking back over history, humanity had just kept exponentially increasing its power use as technology advanced and the number of people increased, so they just extrapolated this ever-expanding need into the future.

Part 2

Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 6:31am

Dyson spheres: Astronomers report potential candidates for alien structures, and evidence against their existence

There are three ways to look for evidence of alien technological civilizations. One is to look out for deliberate attempts by them to communicate their existence, for example, through radio broadcasts. Another is to look for evidence of them visiting the solar system. And a third option is to look for signs of large-scale engineering projects in space.

A team of astronomers have taken the third approach by searching through recent astronomical survey data to identify seven candidates for alien megastructures, known as Dyson spheres, "deserving of further analysis." Their research is published in the journal Monthly Notices of the Royal Astronomical Society.

This is a detailed study looking for "oddballs" among stars—objects that might be alien megastructures. However, the authors are careful not to make any overblown claims. The seven objects, all located within 1,000 light-years of Earth, are "M-dwarfs"—a class of stars that are smaller and less bright than the sun.
Dyson spheres were first proposed by the physicist Freeman Dyson in 1960 as a way for an advanced civilization to harness a star's power. Consisting of floating power collectors, factories and habitats, they'd take up more and more space until they eventually surrounded almost the entire star like a sphere.

What Dyson realized is that these megastructures would have an observable signature. Dyson's signature (which the team searched for in the recent study) is a significant excess of infrared radiation. That's because megastructures would absorb visible light given off by the star, but they wouldn't be able to harness it all. Instead, they'd have to "dump" excess energy as infrared light with a much longer wavelength.
Part 1

Comment by Dr. Krishna Kumari Challa on May 27, 2024 at 6:52am

Anendophasia: not having any inner speech

In recent years have scientists found that not everyone has the sense of an inner voice – and a new study sheds some light on how living without an internal monologue affects how language is processed in the brain.

This is similar to anauralia, a term researchers coined in 2021 for people who don't have an inner voice, nor can they imagine sounds, like a musical tune or siren.

Focusing on inner voices in a study, a research  team recruited 93 volunteers, half of whom said they had low levels of inner speech, while the other half reported having a very chatty internal monologue. These participants attempted a series of tasks – including one where they had to remember the order of words in a sequence, and another where rhyming words had to be paired together.

It is a task that will be difficult for everyone, but the  hypothesis of the researchers was that it might be even more difficult if people  did not have an inner voice because they have to repeat the words to themselves inside their head in order to remember them.

And this hypothesis turned out to be true.

The volunteers who reported hearing inner voices during everyday life did significantly better at the tasks than those without inner monologues: Inner speakers recalled more words correctly, and matched rhyming words faster. The researchers think this could be evidence that inner voices help people process words.

It's interesting to note that the performance differences disappeared when the volunteers spoke out loud to try and solve the problems they were given. It may be that using an audible voice is just as effective as using an inner voice in these situations.

In two other tasks, covering multitasking and distinguishing between different picture shapes, there was no difference in performance. The researchers take this as a sign that the way inner speech affects behavior depends on what we're doing.

Maybe people who don't have an inner voice have just learned to use other strategies. For example, some said that they tapped with their index finger when performing one type of task and with their middle finger when it was another type of task.

The researchers are keen to emphasize that the differences they found would not cause delays that you would notice in regular conversation. Scientists still at the very early stages in terms of figuring out how anendophasia might affect someone – and likewise anauralia.

https://journals.sagepub.com/doi/10.1177/09567976241243004

Comment by Dr. Krishna Kumari Challa on May 25, 2024 at 1:18pm

When a star more massive than about 8 times the mass of the Sun goes supernova, it's extremely messy. The outer layers – most of the star's mass – are explosively ejected into the space around the star, where they form a huge, expanding cloud of dust and gas that lingers for hundreds of thousands to millions of years.

Meanwhile, the star's core, no longer supported by the outward pressure of fusion, collapses under gravity to form an ultradense object, a neutron star or a black hole, depending on the initial star's mass.

These collapsed cores don't always stay put; if the supernova explosion is lopsided, this can punt the core off into space in a natal kick. We can also sometimes trace the core's trajectory back to the cloud of material it ejected as it died, but if enough time has elapsed, the material may have dissipated. But the signs of the natal kick can remain a lot longer.

VFTS 243 is a very interesting system. It consists of a massive star that's around 7.4 million years old and around 25 times the mass of the Sun, and a black hole around 10 times the mass of the Sun.

Although we can't see the black hole directly, we can measure it based on the orbital motion of its companion star – and, of course, we can infer other things about the system. One interesting thing is the shape of the orbit. It's almost circular. This, together with the motion of the system in space, suggests that the black hole did not receive a huge kick from a supernova. The researchers who discovered the black hole back in 2022 suspected as much; now, the work of Vigna-Gómez and his colleagues have confirmed it. There has been a growing body of evidence that suggests that sometimes, massive stars can collapse directly into black holes, without passing supernova or collecting 200 space dollars. VFTS 243 represents the best evidence we have for this scenario to date.

Our results highlight VFTS 243 as the best observable case so far for the theory of stellar black holes formed through total collapse, where the supernova explosion fails and which our models have shown to be possible," says astrophysicist Irene Tamborra of the Niels Bohr Institute. "It is an important reality check for these models. And we certainly expect that the system will serve as a crucial benchmark for future research into stellar evolution and collapse."

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.191403

Part 2

Comment by Dr. Krishna Kumari Challa on May 25, 2024 at 1:16pm

Why some huge stars have disappeared from the sky

When massive stars die, as we understand the Universe, they don't go quietly. As their fuel runs out, they become unstable, wracked by explosions before finally ending their lives in a spectacular supernova.

But some massive stars, scientists have found, have simply vanished, leaving no trace in the night sky. Stars clearly seen in older surveys are inexplicably absent from newer ones. A star isn't exactly a set of keys – you can't just lose it down the back of the couch. So where the heck do these stars go?

A new study has given us the most compelling explanation yet. Some massive stars, suggest an international team led by astrophysicist Alejandro Vigna-Gómez of the Niels Bohr Institute in Denmark and the Max Planck Institute for Astrophysics in Germany, can die, not with a bang, after all, but a whimper.

Their evidence? A binary system named VFTS 243 in the Large Magellanic Cloud, consisting of a black hole and a companion star. This system shows no signs of a supernova explosion that, according to the models, ought to have accompanied the formation of the black hole.

Were one to stand gazing up at a visible star going through a total collapse, it might, just at the right time, be like watching a star suddenly extinguish and disappear from the heavens.

The collapse is so complete that no explosion occurs, nothing escapes and one wouldn't see any bright supernova in the night sky. Astronomers have actually observed the sudden disappearance of brightly shining stars in recent times. Scientists cannot be sure of a connection, but the results they have obtained from analyzing VFTS 243 has brought them much closer to a credible explanation.

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