Weird Quantum Discovery Says Pushing Particles Forward Can Make Them Go Backward
Scientists discover a counterintuitive property of quantum particles called "backflow".
Quantum mechanics continues to provide brain-busting discoveries as mathematicians find that quantum mechanical particles can move in the opposite direction of where they are being pushed. That’s like pushing a ball forward and having it roll back towards you instead.
Scientists at Universities of York, Munich and Cardiff showed that on microscopic levels, quantum particles can travel in reverse of their momentum, exhibiting a special property called “backflow”.
Researchers were aware of such movement previously but in free” quantum particles that don’t have any force acting on them. By using analysis and numerical methods, they found that backflow is always there, but as a small hard-to-measure effect.
What’s responsible for this surprising property? Wave-particle duality, which holds that every particle may behave as a particle or a wave, and the “probabilistic nature” of quantum mechanics where particle properties are not fixated until observed.
Dr. Henning Bostelmann from the University of York Department of Mathematics elaborated on the finding:
“This new theoretical analysis into quantum mechanical particles shows that this ‘backflow’ effect is ubiquitous in quantum physics,” said Bostelmann in a press release. “We have shown that backflow can always occur, even if a force is acting on the quantum particle while it travels. The backflow effect is the result of wave-particle duality and the probabilistic nature of quantum mechanics, and it is already well understood in an idealised case of force-free motion.”
Dr. Daniela Cadamuro from the Technical University of Munich explained that while the scientists were aware of the backflow effect, it was always observed when no outside forces were acting on a particle, and the researchers showed that backflow continues to occur even with external forces present, meaning that such forces “don't destroy the backflow effect, which is an exciting new discovery.”
The practical implications of this discovery may lead to stronger computer encryption. The effect hasn’t been lab-tested yet but scientists are working on setting up appropriate experiments, perhaps with Bose-Einstein condensates. They were used earlier this year to create a superfluid with “negative mass,” where particles exhibited similarly counterintuitive behavior.
Notably, Albert Einstein remarked upon the weirdness one faces when confronted with quantum mechanics:
"It seems as though we must use sometimes the one theory and sometimes the other, while at times we may use either. We are faced with a new kind of difficulty. We have two contradictory pictures of reality; separately neither of them fully explains the phenomena of light, but together they do,” wrote Einstein in a 1938 book with Leopold Infeld.
Want to learn more about wave particle duality?
The Lumina Foundation lays out steps for increasing access to quality post-secondary education credentials.
- America's post-high school education landscape was not created with the modern student in mind. Today, clear and flexible pathways are necessary to help individuals access education that can help them lead a better life.
- Elizabeth Garlow explains the Lumina Foundation's strategy to create a post-secondary education system that works for all students. This includes credential recognition, affordability, a more competency-based system, and quality assurance.
- Systemic historic factors have contributed to inequality in the education system. Lumina aims to close those gaps in educational attainment.
- In 2019, Lumina Foundation and Big Think teamed up to create the Lumina Prize, a search to find the most innovative and scalable ideas in post-secondary education. You can see the winners of the Lumina Prize here – congratulations to PeerForward and Greater Commons!
French newspapers report that the trial hasn't lived up to expectations.
- The French government initially invested in a rural solar roadway in 2016.
- French newspapers report that the trial hasn't lived up to expectations.
- Solar panel "paved" roadways are proving to be inefficient and too expensive.
During World War II, the U.S. incarcerated over 100,000 Japanese Americans in concentration camps throughout the West.
- Now that the issue of concentration camps in the U.S. has once again reared its head, it can be beneficial to recall the last time such camps were employed in the U.S.
- After Pearl Harbor, the U.S. incarcerated over 100,000 Japanese Americans in camps, ostensibly for national security purposes.
- In truth, the incarceration was primarily motivated by racism. What was life like in the U.S.'s concentration camps?
On February 19, 1942, President Roosevelt issued Executive Order 9066, which authorized and directed military commanders "to prescribe military areas … from which any or all persons may be excluded, and with respect to which, the right of any person to enter, remain in, or leave shall be subject to whatever restrictions the Secretary of War or the appropriate Military Commander may impose in his discretion." Under the authority of this executive order, roughly 112,000 men, women, and children of Japanese descent — nearly two-thirds of which were American citizens — were detained in concentration camps.
How did the camps get their start?
With the benefit of a nearly 80-year perspective, it's clear that the internment of Japanese Americans was racially motivated. In response to Japan's growing military power in the buildup to World War II, President Roosevelt commissioned two reports to determine whether it would be necessary to intern Japanese Americans should conflict break out between Japan and the U.S. Neither's conclusions supported the plan, with one even going so far as to "certify a remarkable, even extraordinary degree of loyalty among this generally suspect ethnic group." But of course, the Pearl Harbor attacks proved to be far more persuasive than these reports.
Pearl Harbor turned simmering resentment against the Japanese to a full boil, putting pressure on the Roosevelt administration to intern Japanese Americans. Lieutenant General John DeWitt, who would become the administrator of the internment program, testified to Congress
"I don't want any of them here. They are a dangerous element. There is no way to determine their loyalty... It makes no difference whether he is an American citizen, he is still a Japanese. American citizenship does not necessarily determine loyalty... But we must worry about the Japanese all the time until he is wiped off the map."
DeWitt's position was backed up by a number of pre-existing anti-immigrant groups based out of the West Coast, such as the Joint Immigration Committee and the Native Sons and Daughters of the Golden West. For many, the war simply served as an excuse to get rid of Japanese Americans. In an interview with the Saturday Evening Post, Austin Anson, the managing secretary of the Salinas Vegetable Grower-Shipper Administration, said:
"We're charged with wanting to get rid of the Japs for selfish reasons. We do. It's a question of whether the White man lives on the Pacific Coast or the brown men. ... If all the Japs were removed tomorrow, we'd never miss them in two weeks because the White farmers can take over and produce everything the Jap grows. And we do not want them back when the war ends, either."
Ironically for Anson, the mass deportation of Japanese Americans under Executive Order 9066 meant there was a significant shortage of agricultural labor. Many Caucasians left to fight the war, so the U.S. signed an agreement with Mexico to permit the immigration of several million Mexicans agricultural workers under the so-called bracero program.
Life in the camps
Hulton Archive/Getty Images
Circa 1943: Aerial view of a Japanese American relocation center in Amache, Colorado, during World War II. Each family was provided with a space 20 by 25 ft. The barracks were set in blocks and each block was provided with a community bath house and mess hall.
For the most part, Japanese Americans remained stoic in the face of their incarceration. The phrase shikata ga nai was frequently invoked — the phrase roughly translates to "it cannot be helped," which, for many, represents the perceived attitude of the Japanese people to withstand suffering that's out of their control.
Initially, most Japanese Americans were sent to temporary assembly centers, typically located at fairgrounds or racetracks. These were hastily constructed barracks, where prisoners were often packed into tight quarters and made to use toilets that were little more than pits in the ground. From here, they were relocated to more permanent camps — replete with barbed wire and armed guards — in remote, isolated places across the seven states of California, Arizona, Colorado, Wyoming, Idaho, Utah, and Arkansas.
Many of these camps, also known as War Relocation Centers, were little better than the temporary assembly centers. One report described the buildings as "tar paper-covered barracks of simple frame construction without plumbing or cooking facilities of any kind." Again, overcrowding was common.
As a result, disease became a major concern, including dysentery, malaria, and tuberculosis. This was problematic due to the chronic shortage of medical professionals and supplies, an issue that was not helped by the War Relocation Authority's decision to cap Japanese American medical professional's pay at $20 a month (about $315 in 2019 dollars), while Caucasian workers had no such restriction. As a comparison, Caucasian nurses earned $150 ($2,361) a month in one camp.
The U.S. government also administered loyalty questionnaires to incarcerated Japanese Americans with the ultimate goal of seeing whether they could be used as soldiers and to segregate "loyal" citizens from "disloyal" ones. The questionnaires often asked whether they would be willing to join the military and if they would completely renounce their loyalty to Japan. Due to fears of being drafted, general confusion, and justified anger at the U.S. government, thousands of Japanese Americans "failed" the loyalty questionnaire and were sent to the concentration camp at Tule Lake. When Roosevelt later signed a bill that would permit Japanese Americans to renounce their citizenship, 98 percent of the 5,589 who did were located at Tule Lake. Some apologists cite this an example of genuine disloyalty towards the U.S., but this argument clearly ignores the gross violation of Japanese Americans' rights. Later, it became clear that many of these renunciations had been made under duress, and nearly all of those who had renounced their citizenship sought to gain it back.
Since many children lived in the camps, they came equipped with schools. Of course, these schools weren't ideal — student-teacher ratios reached as high as 48:1, and supplies were limited. The irony of learning about American history and ideals was not lost on the students, one of whom wrote in an essay --
"They, the first generation [of Japanese immigrants], without the least knowledge of the English language nor the new surroundings, came to this land with the American pioneering spirit of resettling. ...Though undergoing many hardships, they did reach their goal only to be resettled by the order of evacuation under the emergency for our protection and public security."
Potentially the best part of life in the camps — and the best way for determined prisoners to demonstrate their fundamental American-ness — was playing baseball. One camp even featured nearly 100 baseball teams. Former prisoner Herb Kurima recalled the importance of baseball in their lives in an interview with Christian Science Monitor. "I wanted our fathers, who worked so hard, to have a chance to see a ball game," he said. "Over half the camp used to come out to watch. It was the only enjoyment in the camps."
When the camps finally closed in 1945, the lives of the incarcerated Japanese Americans had been totally upended. Some were repatriated to Japan, while others settled in whichever part of the country they had been arbitrarily placed in. Those who wished to return to the West Coast were given $25 and a train ticket, but few had anything to return to. Many had sold their property to predatory buyers prior to being incarcerated, while theft had wiped out whatever else they had left behind. Many, many years later, the 1988 Civil Liberties Act mandated that each surviving victim be paid $20,000, though that seems like a small fine to pay for irrevocably changing the courses of more than 100,000 lives.