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In quantum entanglement first, scientists link distant large objects
Physicists create quantum entanglement, making two distant objects behave as one.
Light goes through the atomic cloud in the center and falls onto the membrane on the left. Because of the interaction with light the precession of atomic spins and vibration of the membrane become quantum correlated.
Credit: Niels Bohr Institute
Scientists entangled two large quantum objects, both at different locations from each other, in a quantum mechanics first. The feat is a step towards practical application of a rather counterintuitive phenomenon and was accomplished by a team from the Niels Bohr Institute at the University of Copenhagen.
Entanglement is the magical-sounding concept, dubbed "spooky action at a distance" by Einstein. It involves a link is made between two objects that can make them behave like one. This technique is of paramount importance to quantum communication and quantum sensing, explained the University's press release.
The researchers, led by Professor Eugene Polzik, used light particles photons to create an entanglement between a mechanical oscillator ("a vibrating dielectric membrane") and a cloud of atoms, with each acting like a tiny magnet or "spin". They picked these particular objects because atoms can be made to process quantum information while the membrane can store that information.
"With this new technique, we are on route to pushing the boundaries of the possibilities of entanglement," stated professor Polzik. "The bigger the objects, the further apart they are, the more disparate they are, the more interesting entanglement becomes from both fundamental and applied perspectives. With the new result, entanglement between very different objects has become possible."
By entangling the systems, the scientists made them move in correlation with each other. If one object went left, so did the other.
The achievement can pave the way to new sensing technologies. One example would be getting rid of noisy fluctuations currently affecting the Laser Interferometer Gravitational-wave Observatory (LIGO), which detects gravity waves. If the researchers were able to take information from one system and apply it in another, they could get more precise readings.
While the new technology is promising, research into creating useable devices based on quantum mechanics is very challenging, as explained by Ph.D. student Christoffer Østfeldt:
"Imagine the different ways of realizing quantum states as a kind of zoo of different realities or situations with very different qualities and potentials," he shared.
If one was to try to make a device using quantum states that would all have different functions, "it will be necessary to invent a language they are all able to speak. The quantum states need to be able to communicate, for us to use the full potential of the device. That's what this entanglement between two elements in the zoo has shown we are now capable of," Østfeldt added.
Check out the new study in Nature Physics.
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Scientists see 'rarest event ever recorded' in search for dark matter
The team caught a glimpse of a process that takes 18,000,000,000,000,000,000,000 years.
24 April, 2019
Image source: Pixabay
Surprising Science
- In Italy, a team of scientists is using a highly sophisticated detector to hunt for dark matter.
- The team observed an ultra-rare particle interaction that reveals the half-life of a xenon-124 atom to be 18 sextillion years.
- The half-life of a process is how long it takes for half of the radioactive nuclei present in a sample to decay.
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<p>Scientists have observed an extremely rare particle physics event using a detector that's hunting for dark matter, the mysterious material that physicists have yet to observe.</p><p>In a <a href="https://www.nature.com/articles/s41586-019-1124-4" target="_blank">paper published in </a><a href="https://www.nature.com/articles/s41586-019-1124-4" target="_blank">the journal <em>Nature</em></a>, researchers with the XENON Collaboration said they'd observed the radioactive decay of a substance called xenon-124, an isotope of the element xenon — a colorless and odorless noble gas found in tiny amounts in the atmosphere. The event — a "two-neutrino double electron capture" — has eluded scientists for decades. </p><p>It happens when "two protons in a nucleus are simultaneously converted into neutrons by the absorption of two electrons from one of the atomic shells and the emission of two electron neutrinos." After this occurs, the event shoots out a predictable cascade of X-rays and Auger electrons that scientists look for using an ultra-sensitive detector, buried about 5,000 feet beneath Italy's Gran Sasso mountain where it's shielded from cosmic rays.</p><p style="margin-left: 20px;">"We have shown that we can observe the rarest events ever recorded," Ethan Brown, a professor of physics at Rensselaer Polytechnic Institute and co-author of the study, told <em><a href="https://www.newsweek.com/dark-matter-hunters-observe-rarest-event-ever-recorded-1404823" target="_blank">Newsweek</a></em>. "The key finding is that an isotope formerly thought to be completely stable has now been shown to decay on an unimaginably long timescale."</p><p>How long is that timescale? The team estimated that xenon-124's half-life is about 18 sextillion years — or 18,000,000,000,000,000,000,000 years — which is than one trillion times the age of our universe, according to the team. It's the slowest process ever measured directly, the team wrote in a statement. </p><p style="margin-left: 20px;">"It's an amazing to have witnessed this process, and it says that our detector can measure the rarest thing ever recorded," Brown told <a href="https://www.independent.co.uk/life-style/gadgets-and-tech/news/dark-matter-rarest-ever-event-xenon-half-life-radioactive-discovery-breakthrough-latest-science-a8884896.html" target="_blank"><em>The Independent.</em></a></p>
<div id="31261" class="rm-shortcode" data-rm-shortcode-id="F55APY1568274781"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1121097717781028864" data-partner="rebelmouse"><div style="margin:1em 0">We are extremely excited to share with you that we have observed the rarest decay process ever measured! It is the… https://t.co/7ILxlSMGUf</div> — XENON1T (@XENON1T)<a href="https://twitter.com/Xenon1T/statuses/1121097717781028864">1556125499.0</a></blockquote></div><p style="margin-left: 20px;">"We designed the XENON1T experiment to look for dark matter, a new kind of matter that makes up 85 percent of the mass of the universe, but interacts so rarely that it's never been observed," Brown said. "This experiment is so sensitive to very rare events that we can make all kinds of other rare physics measurements. One of those is this decay of xenon-124. Although our primary goal was always the discovery of dark matter, we knew there was a good chance we could see this rare decay, so we set out to do so."</p><p>To get that good chance, the team had to expose their detector to a huge amount of xenon atoms by stocking it with 3.2 tons worth of liquid xenon.</p><p style="margin-left: 20px;">"XENON1T is a giant vat of liquid xenon surrounded by light sensors," Brown said. "When dark matter collides in the xenon, or when a radioactive decay occurs inside, we get a tiny flash of light and a little bunch of charge out of the xenon. We measure these with the light sensors and reconstruct everything we can about the original event that caused the light and charge."</p><p>Although the team didn't observe dark matter — which is the primary purpose of the detector — the recent observations could help scientists learn more about neutrinos, one of the least understood fundamental particles in the universe.</p><p style="margin-left: 20px;">"It proves that this XENON detector technology we use for dark matter is much more versatile," graduate student Christian Wittweg, Ph.D student at the University of Münster in Germany, told <em><a href="https://gizmodo.com/dark-matter-detector-makes-incredible-neutrino-observat-1834270148" target="_blank">Gizmodo</a></em>. "We get all these cool analyses... for free after having built an experiment sensitive enough to hunt for dark matter."</p><p>The team plans to use its newer XENONnT detector to continue hunting for dark matter, the elusive material that's estimated to comprise about <a href="https://bigthink.com/surprising-science/scientists-figure-out-how-to-trap-dark-matter" target="_blank">26.8 percent of all the content in the universe</a>.</p>
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Psychogenic shivers: Why we get the chills when we aren’t cold
Humans are particularly prone to shiver when a group does or thinks the same thing at the same time.
29 October, 2020
Paramount/Getty Images
Mind & Brain
A few years ago, I proposed that the feeling of cold in one's spine, while for example watching a film or listening to music, corresponds to an event when our vital need for cognition is satisfied.
<p> Similarly, I have shown that chills are not solely related to music or film but also to the practice of science (mainly physics and mathematics) and to the social logic of religious rituals. I believe that chills and aesthetic emotions in general can teach us something that we do not know yet. They can help us to understand what truly matters to the mind and to the society of minds.</p><p>When cold or sick, humans shiver. Shivering is a muscle tremor that produces heat which allows the body to maintain its core temperature in a changing world. Human core temperature can vary temporarily between about 28 to 42 degrees Celsius. Outside these thresholds, death occurs. Humans also shiver in the case of a fever, as heat slows down the rate of pathogen growth and improves the immune response of a living body. Goosebumps or piloerection (the bristling of hairs) can be side effects, as the muscle tremor causes hair to become erect which creates a thin layer of air, thus minimising heat loss. Strangely enough, humans also shiver independently of any such events. For instance, certain <em>social</em> <em>situations</em> seem to provoke the shivers.</p><p>Humans are particularly prone to shiver when a group does or thinks the same thing at the same time. When a crowd is sharing a common goal. When they listen to a national anthem or witness self-sacrifice. When they die for their ideas. When collective thought becomes more important than individual life. But humans also shiver from situations that are not social in nature. Some shiver when they manage to find a solution to certain mathematical problems for example, and so shivering cannot be reduced to a social mechanism.</p>
<p>Why does a psychological event trigger a physiological response related to the regulation of temperature? At a fundamental level, cognition requires change. If you stabilise a retina using adequate instruments, the organ ceases to transmit signals to the primary visual cortex, and one gradually becomes blind. From the standpoint of the sense organ, the same object never appears similar to itself twice. Two chairs are never exactly the same. In other words, one is constantly <em>discovering</em> a visual field. Everything you feel, you feel for the first time. Perception is really exploration and, if we can perceive anything at all, it is because we are constantly matching incoming sensory signals to available mental models. You rarely fail to recognise objects in your surroundings. The world is always already meaningful, and it is sometimes beautiful.</p><p>The process by which a mind adapts to its world is so effective that people constantly mistake one for the other. When a large part of thought matches a large part of world, one might consciously feel what we call <em>aesthetic emotions</em>. Historically, aesthetics is the science of how perception meets cognition, the science of how you know what you see. The majority of aesthetic emotions are unconscious. They occur every time you see something. When you see something important enough, you might experience these emotions consciously. This happens through bodily changes such as tears, heartbeat increase, sweat – or shivers. The strange thing with shivering is that humans seem to shiver both when they are perfectly capable of predicting the behaviour of external objects in real time, when it all fits together so well, and, surprisingly, when nothing at all can be predicted, when the situation goes out of control.</p><p>I <a href="https://www.researchgate.net/publication/322960506_Physics_of_mind_Experimental_confirmations_of_theoretical_predictions" target="_blank">propose</a> that psychogenic shivers correspond to an event where the measure of the total similarity between all sensory signals and available mental models reaches a local peak value. This can be expressed mathematically in terms of the rate of change of a function of conditional similarity. In this context, any change in learning corresponds to an aesthetic emotion. When the function reaches a local maximum, its derivative tends toward zero, and learning slows down. This corresponds to a 'turning' point in your total knowledge. Ten years ago, Perlovsky <a href="https://www.researchgate.net/publication/222526625_Toward_Physics_of_the_Mind_Concepts_Emotions_Consciousness_and_Symbols" rel="noopener noreferrer" target="_blank">predicted</a> that such an event should involve knowledge about other minds and about the meaning of life.</p><p>We know that psychogenic shivers can be inhibited by an excitant, the opioid-antagonist naloxone. Naloxone is what you would inject in a clinical setting to a patient who is victim of an overdose; it is the antagonist of morphine. It does not come as a surprise that most of my subjects state that they relax after they experience an aesthetic shiver. Besides a clear analogy with the sexual drive, what does this tell us about the exploratory drive?</p>
<p>I <a href="https://www.researchgate.net/publication/319081452_Dynamics_of_the_knowledge_instinct_Effects_of_incoherence_on_the_cognitive_system" target="_blank">argue</a> that stories that provoke the shivers might bring about this relief of tension by allowing humans to overcome conflicts among fundamental parts of the mind. Such stories might help us to deal with internal contradictions, where both elements are equally resistant to change. Leon Festinger, who in 1957 invented the theory of cognitive dissonance, named this a dissonance of maximum amplitude. The mind creates stories to overcome its own contradictions. Anthropologists call this a myth, and we know from a wealth of work in anthropology that rituals are likely to provoke shivers down the spine.</p><p>We give two examples for such fundamental conflicts; one is biological and the other cultural. The biological conflict derives from the fact that, while we survive as a species by sharing goals, we might never access the goal of other minds directly. We thus shiver in cases of seemingly total communication – theoretical synchrony. Another example derives from the fundamental discordance between the altruistic nature of the human animal on the one hand, and the logic of the currently dominant social system on the other. These hypotheses would explain why you might shiver in the course of a film when empathy becomes a necessary condition to reduce narrative tension to its minimum. When the bad guy ends up saving the good guy.</p><p>There are three plausible explanations for the fundamental relation between cognition and temperature. One is physiological, the other is physical, and the third is biological. The physiological explanation simply consists of describing psychogenic shivers as a case of fever. The relation between emotion and temperature is in fact very ancient, and even reptiles display evidence of stress-induced hyperthermia.</p><p>The physical explanation relates the dissipation of heat at the shiver to the processing of information in the brain. In 1961 the physicist Rolf Landauer at IBM proposed the principle that any erasure of information should be accompanied by the dissipation of heat. This was verified experimentally a few years ago in Lyon. If this hypothesis is not entirely false, then we should eventually be able to predict the amount of heat produced, given accurate knowledge of the information process. Until then, I do not see any good reason to quantify the shiver.</p><p>Finally, the biological explanation relates the origins of human thought to the tremendous changes in temperature at its <a href="https://link.springer.com/chapter/10.1007%2F978-1-4615-1221-9_1" target="_blank">birth</a>. It might be that we can observe this relation between the mechanisms that regulate cognition and the mechanisms that regulate temperature because of the particular context in which thought saw the light of day. In other words, a shiver might have very well accompanied the first human idea. Since then, every time we grasp something important, perhaps we repeat the gesture.<img src="https://metrics.aeon.co/count/5ecd542b-78b8-4a38-9fb8-ad74d95c1d64.gif" alt="Aeon counter – do not remove"></p><p>Félix Schoeller</p><p>This article was originally published at <a href="https://aeon.co/?utm_campaign=republished-article" target="_blank">Aeon</a> and has been republished under Creative Commons.</p>
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COVID-19 may cause 'significant' cognitive deficits, study says
A growing body of research suggests COVID-19 can cause neurological damage in some patients.
28 October, 2020
Feydzhet Shabanov via AdobeStock
Coronavirus
- The study examined data of cognitive performance collected from more than 84,000 people, more than 12,000 of whom had likely contracted and recovered from COVID-19.
- Compared to healthy participants, the COVID-19 group performed significantly worse on cognitive tests.
- Mental decline in the worst cases were the equivalent of ageing by 10 years.
<p>A new study adds to the <a href="https://bigthink.com/coronavirus/covid-19-brain" target="_blank">growing body of research</a> suggesting COVID-19 may leave some patients with neurological damage.</p><p>The preprint study — which is <a href="https://www.medrxiv.org/content/10.1101/2020.10.20.20215863v1.full" target="_blank">published in medRxiv</a> and has yet to be peer reviewed — examined cognitive test data from 84,285 people, more than 12,000 of whom had either tested positive for COVID-19 or had likely contracted the disease based on previous symptoms.</p><p>The data was collected from the Great British Intelligence Test, which measures cognitive performance in areas like semantic reasoning abilities, spatial problem solving and verbal working memory, to name a few.</p><p>The results showed that people who contracted and recovered from COVID-19 were significantly more likely to score lower on the tests. What's more, people with more severe cases of the disease tended to show greater cognitive deficits.</p><p>Because the researchers didn't have data on participants' cognitive abilities before the pandemic, they compared the scores of the COVID-19 group with a group of healthy controls.</p><p style="margin-left: 20px;">"People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders," the researchers wrote in the study. "They were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty."</p>
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYyNzkzMS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1NjU3ODYzMn0.JtLPDziG7DUaxgB8TbhcTr0WUlA1Z6lbPQGQuokL70A/img.png?width=980" id="220a0" class="rm-shortcode" data-rm-shortcode-id="d57d248db201d1179b3d6e82082b66fe" data-rm-shortcode-name="rebelmouse-image" />
The effect size of cognitive deficits varied across three cognitive domains, which were estimated by applying principal component analysis with varimax rotation to the nine test summary scores.
Hampshire et al.
<p>Participants who suffered the most severe cases of COVID-19, and had to be put on a respirator, showed cognitive "equivalent to the average 10-year decline in global performance between the ages of 20 to 70." For comparison, the study notes that the difference in cognitive performance between this group and the control "equates to an 8.5-point difference in IQ."<br></p><p>The COVID-19 group scored particularly low on tests measuring semantic problem solving and visual selective attention.</p><p style="margin-left: 20px;">"People who have recovered from COVID-19 infection show particularly pronounced problems in multiple aspects of higher cognitive or 'executive' function, an observation that accords with preliminary reports of executive dysfunction in some patients at hospital discharge," the researchers wrote.</p><p>Considering that all participants had recovered from the disease when they completed the cognitive tests, the results suggest that "COVID-19 infection likely has consequences for cognitive function that persist into the recovery phase," the researchers wrote.</p><p>Still, it's unclear whether these deficits (if indeed caused by COVID-19) are permanent, or how long they may last. But there is evidence suggesting that severe respiratory conditions can cause neurological damage. A <a href="https://link.springer.com/article/10.1186/s13054-019-2626-z" target="_blank">2011 study</a>, for example, found that people who'd been hospitalized with acute respiratory distress syndrome can suffer cognitive deficits that persist up to five years after discharge.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYyNzk1Ny9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYwNjQ4MDUwMX0.j0bjS0TpgNEvfeeUtgZF-u5x9VrrEARBiz7ICjOmTzo/img.png?width=980" id="944aa" class="rm-shortcode" data-rm-shortcode-id="e70e7ab26f9f41c66ae98dd97fb025dd" data-rm-shortcode-name="rebelmouse-image" />
The Block Rearrange test [featured in the Great British Intelligence Test] measures spatial problem solving.
Credit: Hampshire et al.
<p>It's worth noting the study is limited, mainly because it didn't compare before-and-after cognitive performance of the COVID-19 group. Another possible limitation: People with lower cognitive abilities may be more likely to contract COVID-19 because they're more likely to put themselves in harm's way.</p><p style="margin-left: 20px;">"We consider such a relationship plausible; however, it would not explain why the observed deficits varied in scale with respiratory symptom severity," the researchers wrote. "We also note that the large and socioeconomically diverse nature of the cohort enabled us to include many potentially confounding variables in our analysis."</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYyNzk2MS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYwNDQ1NzgxOX0.ekExdMWbfgcNMYb3m-yyXT867zzsWP-3HG-59u_QngQ/img.png?width=980" id="eb48c" class="rm-shortcode" data-rm-shortcode-id="76b5f48c920a441400e0b8965ad2cbe0" data-rm-shortcode-name="rebelmouse-image" alt="Doctors treating a COVID-19 patient" />
San Diego-area hospitals treat coronavirus patients during COVID-19 pandemic
Credit: Mario Tama/Getty Images
<p>Only time and further research will tell whether COVID-19 leaves people with lasting cognitive deficits. Scientists are already establishing long-term research projects to answer these questions, such as the <a href="https://www.cambridgebrainsciences.com/studies/covid-brain-study" target="_blank" rel="noopener noreferrer">COVID-19 Brain Study</a>, which aims to monitor the long-term health of 50,000 participants who have tested positive for the disease.</p><p>If you've been diagnosed with COVID-19 and want to enroll in the study, visit <a href="https://www.cambridgebrainsciences.com/studies/covid-brain-study" target="_blank" rel="noopener noreferrer">cambridgebrainsciences.com/studies/covid-brain-study</a>.</p>
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Mind & Brain
What we want from horror is a cardiac jump-start, study suggests
A study looks at the ingredients of a good scare.
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