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Are scientists on the brink of discovering a mirror universe?
New experiments look to the interplay between neutrons and magnetic fields to observe our universal reflection.
- Science fiction has long speculated about parallel universes and what they may be like.
- Researchers have devised new experiments to look for how a mirror universe may be influencing our own.
- If such evidence is found, it could bring to light many of the universe's mysteries, such as the nature of dark matter.
In the original Star Trek episode "Mirror, Mirror," the crew of the Enterprise are accidentally transported to a parallel universe. Dubbed the Mirror Universe, its denizens are evil doppelgangers of the crew, complete with garish uniforms, Nazi-like salutes, and full, robust goatees.
Like many concepts first imagined in science fiction, the mirror universe may actually exist, albeit in a far less melodramatic form.
As reported by New Scientist, physicists are busy speculating about our universal reflection, and two experiments are currently underway to search out the empirical evidence. If proof of a mirror universe is found, it may help solve many of physics most intractable questions.
Searching for our own reflection
At the Oak Ridge National Laboratory's traveling science fair, participants can experience life as a ion and then a neutron in a neutron beam. Photo credit: Genevieve Martin / ORNL / Flickr
The first experiment profiled by New Scientist comes courtesy of physicist Leah Broussard and her team at the Oak Ridge National Laboratory in Tennessee. They have devised a simple method for detecting a mirror universe.
An apparatus will fire a beam of neutrons at a wall with varying magnetic fields on both sides. These neutrons can't penetrate the wall, yet the researchers have placed a device behind it that will scan the area for these very subatomic particles.
Why? If any neutrons manage to appear behind the wall, it will be strong evidence that they oscillated into mirror neutrons, skipped right on pass the wall because it existed in a different part of the universe, and then oscillated back in time to hit the detection device.
"Only the [neutrons] that can oscillate and then come back into our universe can be detected," Broussard told New Scientist. "When passing through a magnetic field, the oscillation probability increases."
Broussard and her team are looking at neutrons because of a quirk in their decay.
Inside a nucleus, neutrons are perfectly stable, but outside, they decay into a proton, an electron, and an antineutrino of the electron type. Here's the quirk: all free neutrons should decay at the same rate, but that rate changes depending on how scientists measure it.
The first way to measure the lifetime of free neutrons is to isolate them in a "bottle trap" and then count how many remain after a certain amount of time. The second way is to count the protons emerging from a neutron beam generated by a nuclear reactor. Yet, scientists get different rates of decay for each — 14 minutes 39 seconds for the former, 14 minutes 48 seconds for the latter.
A possible explanation for this discrepancy is a mirror universe. Neutrons may have dual citizenship in both universes. When they summer in our neighboring universe, any protons they emit are not detected and therefore not counted in our measurements. This could explain why we see less decay activity in the neutron beam.
Signals in magnetic fields
The second experiment profiled by New Scientist was developed by Klaus Kirch and his team at the Paul Scherrer Institute in Switzerland. This team applied magnetic fields of varying strengths to neutrons in a bottle trap.
The goal is to find the telltale signals of mirror magnetic fields. These would suggest neutrons oscillating between universes, potentially supporting any evidence found by Broussard and her team.
"The experimentalist's view is, if it doesn't look completely crazy, can it be tested?" Kirch told New Scientist. "I don't really believe the signals are there, and we have designed an experiment that can disprove them, and we'll see what comes out of it."
Kirch and his team have completed their experiment and are currently analyzing the data.
A mirror darkly
As Yuri Kamyshkov, a mirror matter researcher at the University of Tennessee and a collaborator with Broussard, noted: "The probability of finding anything is low, but it's a simple and inexpensive experiment." Despite the odds, he adds, a positive result would usher in a physics revolution.
A mirror universe could explain many of physics' unsolved mysterious, among them the question of dark matter. As Michio Kaku told Big Think in an interview:
"Dark matter is massive, it has gravity, but it's invisible. It has no interactions with light or the electromagnetic force. So, there is a theory that says that perhaps dark matter is nothing but matter, ordinary matter, in another dimension hovering right above us."
Of course, Kaku points out, this is one of many different theories about dark matter. String theorists think dark matter may be a higher octave of string vibration.
One reason the mirror universe idea is so appealing is the math. Some models suggest a mirror universe would have to have been much cooler than our own during its early evolution. This difference would have made it easier for particles to cross over, resulting in five mirror particles for every regular one. That's roughly the ratio of dark to normal matter.
Scientific models, in the end, must be backed by empirical evidence. We'll have to wait for the results of these and other experiments before determining the probability that a mirror universe exists — let alone if its beard game can match our own.
Construction of the $500 billion dollar tech city-state of the future is moving ahead.
- The futuristic megacity Neom is being built in Saudi Arabia.
- The city will be fully automated, leading in health, education and quality of life.
- It will feature an artificial moon, cloud seeding, robotic gladiators and flying taxis.
The Red Sea area where Neom will be built:
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A new study suggests that a century-old vaccine may reduce the severity of coronavirus cases.
- A new study finds a country's tuberculosis BCG vaccination is linked to its COVID-19 mortality rate.
- More BCG vaccinations is connected to fewer severe coronavirus cases.
- The study is preliminary and more research is needed to support the findings.
Professor Luis Escobar.
Credit: Virginia Tech
A study of the manner in which memory works turns up a surprising thing.
- Researchers have found that some basic words appear to be more memorable than others.
- Some faces are also easier to commit to memory.
- Scientists suggest that these words serve as semantic bridges when the brain is searching for a memory.
Cognitive psychologist Weizhen Xie (Zane) of the NIH's National Institute of Neurological Disorders and Stroke (NINDS) works with people who have intractable epilepsy, a form of the disorder that can't be controlled with medications. During research into the brain activity of patients, he and his colleagues discovered something odd about human memory: It appears that certain basic words are consistently more memorable than other basic words.
The research is published in Nature Human Behaviour.
An odd find
Image source: Tsekhmister/Shutterstock
Xie's team was re-analyzing memory tests of 30 epilepsy patients undertaken by Kareem Zaghloul of NINDS.
"Our goal is to find and eliminate the source of these harmful and debilitating seizures," Zaghloul said. "The monitoring period also provides a rare opportunity to record the neural activity that controls other parts of our lives. With the help of these patient volunteers we have been able to uncover some of the blueprints behind our memories."
Specifically, the participants were shown word pairs, such as "hand" and "apple." To better understand how the brain might remember such pairings, after a brief interval, participants were supplied one of the two words and asked to recall the other. Of the 300 words used in the tests, five of them proved to be five times more likely to be recalled: pig, tank, doll, pond, and door.
The scientists were perplexed that these words were so much more memorable than words like "cat," "street," "stair," "couch," and "cloud."
Intrigued, the researchers looked at a second data source from a word test taken by 2,623 healthy individuals via Amazon's Mechanical Turk and found essentially the same thing.
"We saw that some things — in this case, words — may be inherently easier for our brains to recall than others," Zaghloul said. That the Mechanical Turk results were so similar may "provide the strongest evidence to date that what we discovered about how the brain controls memory in this set of patients may also be true for people outside of the study."
Why understanding memory matters
Image source: Orawan Pattarawimonchai/Shutterstock
"Our memories play a fundamental role in who we are and how our brains work," Xie said. "However, one of the biggest challenges of studying memory is that people often remember the same things in different ways, making it difficult for researchers to compare people's performances on memory tests." He added that the search for some kind of unified theory of memory has been going on for over a century.
If a comprehensive understanding of the way memory works can be developed, the researchers say that "we can predict what people should remember in advance and understand how our brains do this, then we might be able to develop better ways to evaluate someone's overall brain health."
Image source: joob_in/Shutterstock
Xie's interest in this was piqued during a conversation with Wilma Bainbridge of University of Chicago at a Christmas party a couple of years ago. Bainbridge was, at the time, wrapping up a study of 1,000 volunteers that suggested certain faces are universally more memorable than others.
Bainbridge recalls, "Our exciting finding is that there are some images of people or places that are inherently memorable for all people, even though we have each seen different things in our lives. And if image memorability is so powerful, this means we can know in advance what people are likely to remember or forget."
Image source: Anatomography/Wikimedia
At first, the scientists suspected that the memorable words and faces were simply recalled more frequently and were thus easier to recall. They envisioned them as being akin to "highly trafficked spots connected to smaller spots representing the less memorable words." They developed a modeling program based on word frequencies found in books, new articles, and Wikipedia pages. Unfortunately, the model was unable to predict or duplicate the results they saw in their clinical experiments.
Eventually, the researchers came to suspect that the memorability of certain words was linked to the frequency with which the brain used them as semantic links between other memories, making them often-visited hubs in individuals's memory networks, and therefore places the brain jumped to early and often when retrieving memories. This idea was supported by observed activity in participants' anterior temporal lobe, a language center.
In epilepsy patients, these words were so frequently recalled that subjects often shouted them out even when they were incorrect responses to word-pair inquiries.
Modern search engines no longer simply look for raw words when resolving an inquiry: They also look for semantic — contextual and meaning — connections so that the results they present may better anticipate what it is you're looking for. Xie suggests something similar may be happening in the brain: "You know when you type words into a search engine, and it shows you a list of highly relevant guesses? It feels like the search engine is reading your mind. Well, our results suggest that the brains of the subjects in this study did something similar when they tried to recall a paired word, and we think that this may happen when we remember many of our past experiences."
He also notes that it may one day be possible to leverage individuals' apparently wired-in knowledge of their language as a fixed point against which to assess the health of their memory and brain.