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absorption

Scientists Are Figuring Out Why Some People Can ‘Hear’ The Voices of The Dead

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Scientists have identified the traits that may make a person more likely to claim they hear the voices of the dead.

According to new research, a predisposition to high levels of absorption in tasks, unusual auditory experiences in childhood, and a high susceptibility to auditory hallucinations all occur more strongly in self-described clairaudient mediums than the general population.

 

The finding could help us to better understand the upsetting auditory hallucinations that accompany mental illnesses such as schizophrenia, the researchers say.

The Spiritualist experiences of clairvoyance and clairaudience – the experience of seeing or hearing something in the absence of an external stimulus, and attributed to the spirits of the dead – is of great scientific interest, both for anthropologists studying religious and spiritual experiences, and scientists studying pathological hallucinatory experiences.

In particular, researchers would like to better understand why some people with auditory experiences report a Spiritualist experience, while others find them more distressing, and receive a mental health diagnosis.

“Spiritualists tend to report unusual auditory experiences which are positive, start early in life and which they are often then able to control,” explained psychologist Peter Moseley of Northumbria University in the UK.

“Understanding how these develop is important because it could help us understand more about distressing or non-controllable experiences of hearing voices too.”

He and his colleague psychologist Adam Powell of Durham University in the UK recruited and surveyed 65 clairaudient mediums from the UK’s Spiritualists’ National Union, and 143 members of the general population recruited through social media, to determine what differentiated Spiritualists from the general public, who don’t (usually) report hearing the voices of the dead.

 

Overall, 44.6 percent of the Spiritualists reported hearing voices daily, and 79 percent said the experiences were part of their daily lives. And while most reported hearing the voices inside their head, 31.7 percent reported that the voices were external, too.

The results of the survey were striking.

Compared to the general population, the Spiritualists reported much higher belief in the paranormal, and were less likely to care what other people thought of them.

The Spiritualists on the whole had their first auditory experience young, at an average age of 21.7 years, and reported a high level of absorption. That’s a term that describes total immersion in mental tasks and activities or altered states, and how effective the individual is at tuning out the world around them.

In addition, they reported that they were more prone to hallucination-like experiences. The researchers noted that they hadn’t usually heard of Spiritualism prior to their experiences; rather, they had come across it while looking for answers.

In the general population, high levels of absorption were also strongly correlated with belief in the paranormal – but little or no susceptibility to auditory hallucinations. And in both groups, there were no differences in the levels of belief in the paranormal and susceptibility to visual hallucinations.

 

These results, the researchers say, suggest that experiencing the ‘voices of the dead’ is therefore unlikely to be a result of peer pressure, a positive social context, or suggestibility due to belief in the paranormal. Instead, these individuals adopt Spiritualism because it aligns with their experience and is personally meaningful to them.

“Our findings say a lot about ‘learning and yearning’. For our participants, the tenets of Spiritualism seem to make sense of both extraordinary childhood experiences as well as the frequent auditory phenomena they experience as practising mediums,” Powell said.

“But all of those experiences may result more from having certain tendencies or early abilities than from simply believing in the possibility of contacting the dead if one tries hard enough.”

Future research, they concluded, should explore a variety of cultural context to better understand the relationship between absorption, belief, and the strange, spiritual experience of ghosts whispering in one’s ear.

The research has been published in Mental Health, Religion and Culture.

 



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It Looks Like That ‘Impossible’ Black Hole We Just Found Was Actually an Error

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The discovery of an “impossibly” massive black hole in the Milky Way, only announced a couple of weeks ago, now looks to be debunked. Three separate papers available on the pre-print server arXiv have all called out the same problem.

 

The crux of the issue – it appears that the light interpreted as emanating from the accretion disc of the black hole might have another source entirely. This, in turn, means the mass measurement derived from that light is likely incorrect.

To recap, at the end of last month, a team of astronomers led by Jifeng Liu of the National Astronomical Observatory of China published a paper revealing the discovery of LB-1, a stellar-mass black hole 15,000 light-years away.

The astonishing thing about LB-1 was its peculiar mass: 70 times the mass of the Sun.

This sort of mass was thought impossible in the Milky Way, because the hefty stars in the mass range that could produce a black hole like this are expected to end their lives in what is called a pair-instability supernova that completely obliterates the stellar core. No stellar core, no black hole.

LB-1, therefore, was poised to up-end our models of the evolution of massive stars. But there was an illusion in the data.

Liu and his team discovered LB-1 using radial velocity. From what we can tell, the black hole is in a binary system with a star, locked in orbit around a mutual centre of gravity.

Because the black hole is much more massive than the star, it moves less; but it does, in fact, wobble a little as the star’s gravity tugs on it. See the below video for a visualisation of this concept with a planet and star.

If you can see how much each object is moving, you can calculate the masses of the objects. But, according to two astronomers at the University of California, Berkeley, the wobbling light interpreted as emanating from the black hole as it accretes material – the hydrogen-alpha emission line – is not actually wobbling at all.

“We show that there is in fact no evidence for radial velocity variability of the hydrogen-alpha emission line, and that its apparent shifts instead originate from shifts in the luminous star’s hydrogen-alpha absorption line,” they write in their paper, currently submitted to MNRAS Letters.

 

“If not accounted for, such shifts will always cause a stationary emission line to appear to shift in anti-phase with the luminous star.”

In other words, it’s an illusory effect caused by the shifting light of the binary star. When viewed through a spectroscope, starlight is split into a spectrum, the wavelengths of which reveal the chemical composition of the star, since different elements emit and absorb different wavelengths.

An emission line is a bright feature on the light spectrum, created by an atom transitioning from a higher to a lower energy state. Since each element has a unique emission spectrum, this can be used to identify the element. An absorption line, on the other hand, is a darker line, created by the absorption of light by gas. The wavelength of the line can be used to identify said gas.

The researchers found that, once they removed the companion star’s absorption line from the analysis, the hydrogen-alpha emission line stopped wobbling. This, the researchers said, suggests either that the black hole is much, much bigger than 70 solar masses – highly unlikely – or much, much smaller, no more than 20 solar masses.

 

Quite independently, a day earlier, an international team of researchers led by theoretical astronomer JJ Eldridge of the University of Auckland in New Zealand uploaded a paper with a similar conclusion. Rather than re-examining LB-1, however, this team simulated black hole-bright star binary systems at 15,000 light-years away to see if they could get a match for LB-1.

They did get a match, but with much smaller black holes, ones between 4 to 7 solar masses. For LB-1 to be 70 solar masses, they found, it would need to be much farther away; but the Gaia data used by Liu’s team was found to be correct.

“We conclude that the LB-1 system is likely to be explained by a naturally occurring binary containing a black hole of moderate mass (≈ 8 solar masses), rather than one reaching 70 solar masses,” they wrote in their pre-print, which is submitted to MNRAS.

Finally, the third pre-print paper, led by astronomer Michael Abdul-Masih of KU Leuven in Belgium, also homed in on the hydrogen alpha line. Rather than relying on previous observations, this team took their own, using the HERMES spectrograph on the Mercator telescope in the Canary Islands.

Using these new data, the researchers isolated the hydrogen-alpha emission profile by subtracting a theoretical hydrogen-alpha absorption line corresponding with the atmosphere of the binary system’s star. And their result was the same as what UC Berkeley researchers arrived at.

“Consequently, there is no evidence for a large mass-ratio and hence a large absolute mass of the black hole,” they wrote in their pre-print.

None of the three papers have undergone peer review just yet, but the fact that they all arrived at the same conclusions using different methods is pretty compelling. There could very well still be a black hole there, but if there is, these papers suggest that it’s consistent with what we expect to find in the Milky Way.

So nobody will have to rewrite stellar evolution after all.

The three papers are available on arXiv here, here and here.

 



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This Lab Has Built a Prototype ‘Anti-Laser’ That Swallows Light

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In recent years scientists have started exploring the concept of anti-lasers – devices that can perfectly absorb a particular wavelength of light, as opposed to emitting it the way a laser does.

 

Now researchers have published a study that explores the blueprint for building an anti-laser that’s more complex than anything we’ve seen before.

More than an anti-laser, this team’s device is a ‘random anti-laser’: capable of absorbing waves randomly scattered in all directions. This ability could have a variety of potential uses, in everything from phone antennas to medical equipment – anywhere waves are captured.

An anti-laser may sound wild, but it’s actually pretty much what it says on the tin. You can think of such a device as a laser light burst happening in reverse – getting swallowed up rather than beamed out, according to the researchers.

“So far, anti-lasers have only been realised in one-dimensional structures onto which laser light was directed from opposite sides,” says one of the team, Stefan Rotter from the Vienna University of Technology in Austria.

“Our approach is much more general: we were able to show that even arbitrarily complicated structures in two or three dimensions can perfectly absorb a suitably tailored wave. In this way, this novel concept can also be used for a much wider range of applications.”

 

It’s that versatility and flexibility that sets this new anti-laser apart from what previous such devices. The team worked up a set of calculations and computer simulations to theorise how such a perfectly absorbing anti-laser might work, then backed them up with physical lab tests.

Key to the process is finding a wave front for the incoming signals in order to perfectly absorb them. That then enables the absorption of waves that aren’t arriving in predictable ways, but rather as scattered signals bouncing in from multiple sources.

“Waves that are being scattered in a complex way are really all around us – think about a mobile phone signal that is reflected several times before it reaches your cell phone,” says Rotter.

“This multiple scattering is made practical use of in so-called random lasers. Such exotic lasers are based on a disordered medium with a random internal structure that can trap light and emit a very complicated, system-specific laser field when supplied with energy.”

laser light 2The random anti-laser setup. (Vienna University of Technology)

When it came to building their own anti-laser, the scientists set up a series of randomly placed Teflon cylinders, and sent microwave signals scattering through them – a little bit like rocks deflecting water waves in a puddle of water.

A waveguide placed on top with an antenna in its centre was used to absorb the incoming waves. The researchers managed to get an absorption rate of approximately 99.8 percent of the signals they broadcast.

 

That high mark is only in tightly controlled conditions, though – the team first measured the wave reflections as they came back in order to finely tune the central antenna to absorb them. Both the frequency of the signal and the absorption strength have to be carefully calibrated.

As a first attempt though, it’s very promising, and the theoretical physics behind the project suggests it can be adapted to a range of other signals and applications. It could work for any scenario “in which waves need to be perfectly focused, routed or absorbed”, write the researchers.

“Imagine, for example, that you could adjust a cell phone signal exactly the right way, so that it is perfectly absorbed by the antenna in your cell phone,” says Rotter.

“Also in medicine, we often deal with the task of delivering wave energy to a very specific point – such as shock waves shattering a kidney stone.”

Being treated with an anti-laser sounds pretty cool to us.

The research has been published in Nature.

 



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