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Experiment proves old theory of how aliens might use black holes for energy
Researchers create a device to test a 50-year-old physics theory from the famed Roger Penrose.
- Scientists prove a 50-year-old physics theory by Roger Penrose.
- The theory explains how energy could be harvested from black holes by advanced aliens.
- Researchers from the University of Glasgow twisted sound waves to show that the effect Penrose described is real.
A theory proposed 50 years ago to explain how energy might be harvested from a black hole was verified by an experiment. Scientists from the University of Glasgow were able to provide first proof for an idea from 1969 by the famed British physicist Roger Penrose, who predicted that only an advanced alien civilization would be able to get energy in the black hole's ergosphere – the outer layer of its event horizon.
Why would it take aliens to do this? Penrose thought that if you lower an object into the ergosphere, you could produce negative energy. But for this to work, the object would have to be moving faster than the speed of light. Penrose envisioned a mechanism that would split an object dropped into the black hole in two, with one part going into the hole while the other would be recovered. As explains the press release from the University of Glasgow, the recoil generated by this process would result in the saved half gaining energy from the black hole's rotation.
Of course if this sounds complicated, it really is and only a very high-tech futuristic civilization would be up for the challenge, concluded Penrose.
What the scientists were able to do now was to test this idea by an experiment based on the proposal from another physicist, Yakov Zel'dovich. He suggested in 1971 that Penrose's theory could be proven by using "twisted" light waves, which would create energy by hitting a rotating metal cylinder and utilizing the rotational Doppler effect.
While Zel'dovich's approach also proved impractical, the scientists from the Glasgow University's School of Physics and Astronomy devised a setup of a small ring of speakers that twisted sound waves in a way similar to how he wanted to twist light. The advantage is that sound waves need a significantly slower rotating surface compared to light.
Check out how the researchers explain their work
The team sent twisted sound waves towards a rotating sound absorber from a foam disk. Microphones positioned in the back of the disk captured the sound that passed from the speakers through the disc, which spun faster and faster.
What the scientists found was that this process produced clear changes in the frequency and amplitude of the sound waves, courtesy of the unusual behavior of the Doppler effect, which normally describes how for example, the pitch of a siren from an emergency vehicle seems to rise as it heads towards you but drops when it moves away. This happens because sound waves come at you with more frequency when the ambulance closes in, but less so after it goes past.
The paper's lead author, Marion Cromb, a Ph.D. student in the University's School of Physics and Astronomy, explained that rotation transforms this linear effect and pulls in energy. "The rotational doppler effect is similar, but the effect is confined to a circular space," he pointed out. "The twisted sound waves change their pitch when measured from the point of view of the rotating surface. If the surface rotates fast enough then the sound frequency can do something very strange—it can go from a positive frequency to a negative one, and in doing so steal some energy from the rotation of the surface."
The set-up of the experiment.
Credit: University of Glasgow
The researchers were able to show that as they increased the speed of the spinning disc, the pitch of the sound kept dropping until it disappeared, then it came back up to 30 percent louder than before.
Marion called what they heard during the experiment "extraordinary," adding that the "negative-frequency waves are capable of taking some of the energy from the spinning foam disc, becoming louder in the process—just as Zel'dovich proposed in 1971."
Whether aliens are using this approach to get energy from black holes is certainly hard to ascertain, but the researchers are planning to investigate whether this effect extends to other sources like electromagnetic waves.
Check out their new paper "Amplification of waves from a rotating body" in Nature Physics.
Sallie Krawcheck and Bob Kulhan will be talking money, jobs, and how the pandemic will disproportionally affect women's finances.
A recent study on monkeys found that stimulating a certain part of the forebrain wakes monkeys from anesthesia.
- Scientists electrically stimulated the brains of macaque monkeys in an effort to determine which areas are responsible for driving consciousness.
- The monkeys were anesthetized, and the goal was to see whether activating certain parts of the brain would wake up the animals.
- The forebrain's central lateral thalamus seems to be one of the "minimum mechanisms" necessary for consciousness.
Pixabay<p>When the team electrically stimulated a part of the brain called the central lateral thalamus, located in the forebrain, the monkeys woke up: they opened their eyes, blinked, reached out, made facial expressions and showed altered vital signs. </p><p>"We found that when we stimulated this tiny little brain area, we could wake the animals up and reinstate all the neural activity that you'd normally see in the cortex during wakefulness," Saalmann told Cell Press. "They acted just as they would if they were awake. When we switched off the stimulation, the animals went straight back to being unconscious."</p><p>This area of the brain may function as an "engine for consciousness," Redinbaugh told Inverse. Although past studies have shown that electrical stimulation can arouse the brains of humans and animals, the new findings are unique because they reveal which specific neural interactions appear to be minimally necessary for consciousness.</p><p>"Science doesn't often leave opportunity for exhilaration, but that's what that moment was like for those of us who were in the room," Redinbaugh told <a href="https://www.inverse.com/science/first-squid-mri-study-brain-complexity-similar-dogs" target="_blank"><em>Inverse</em></a><em>.</em></p>
Future applications<p>The team said the findings could have many applications down the road, but more research is needed.</p><p>"The overriding motivation of this research is to help people with disorders of consciousness to live better lives," Redinbaugh told Cell Press. "We have to start by understanding the minimum mechanism that is necessary or sufficient for consciousness, so that the correct part of the brain can be targeted clinically."</p><p>"It's possible we may be able to use these kinds of deep-brain stimulating electrodes to bring people out of comas. Our findings may also be useful for developing new ways to monitor patients under clinical anesthesia, to make sure they are safely unconscious."</p>
The word "learning" opens up space for more people, places, and ideas.
- The terms 'education' and 'learning' are often used interchangeably, but there is a cultural connotation to the former that can be limiting. Education naturally links to schooling, which is only one form of learning.
- Gregg Behr, founder and co-chair of Remake Learning, believes that this small word shift opens up the possibilities in terms of how and where learning can happen. It also becomes a more inclusive practice, welcoming in a larger, more diverse group of thinkers.
- Post-COVID, the way we think about what learning looks like will inevitably change, so it's crucial to adjust and begin building the necessary support systems today.
The coronavirus pandemic has brought out the perception of selfishness among many.
- Selfish behavior has been analyzed by philosophers and psychologists for centuries.
- New research shows people may be wired for altruistic behavior and get more benefits from it.
- Crisis times tend to increase self-centered acts.