- Quantum particles can tunnel through seemingly impassable barriers, popping up on the other side.
- Quantum tunneling is not a new discovery, but there's a lot that scientists don't know.
- By super-cooling rubidium particles, researchers use their spinning as a magnetic timer.
When it comes to weird behavior, there's nothing quite like the quantum world. On top of that world-class head scratcher entanglement, there's also quantum tunneling — the mysterious process in which particles somehow find their way through what should be impenetrable barriers.
Exactly why or even how quantum tunneling happens is unknown: Do particles just pop over to the other side instantaneously in the same way entangled particles interact? Or do they progressively tunnel through? Previous research has been conflicting.
That quantum tunneling occurs has not been a matter of debate since it was discovered in the 1920s. When IBM famously wrote their name on a nickel substrate using 35 xenon atoms, they used a scanning probe microscopes to see what they were doing. And tunnel diodes are fast-switching semiconductors that derive their negative resistance from quantum tunneling.
"Quantum tunneling is one of the most puzzling of quantum phenomena," says Aephraim Steinberg of the Quantum Information Science Program at Canadian Institute for Advanced Research in Toronto to Live Science. Speaking with Scientific American he explains, "It's as though the particle dug a tunnel under the hill and appeared on the other."
Steinberg is a co-author of a study just published in the journal Nature that presents a series of clever experiments that allowed researchers to measure the amount of time it takes tunneling particles to find their way through a barrier. "And it is fantastic that we're now able to actually study it in this way."
Frozen rubidium atoms
Image source: Viktoriia Debopre/Shutterstock/Big Think
One of the difficulties in ascertaining the time it takes for tunneling to occur is knowing precisely when it's begun and when it's finished. The authors of the new study solved this by devising a system based on particles' precession.
Subatomic particles all have magnetic qualities and they spin, or "precess," like a top when they encounter an external magnetic field. With this in mind, the authors of the study decided to construct a barrier with a magnetic field, causing any particles passing through it to precess as they did so. They wouldn't precess before entering the field or after, so by observing and timing the duration of the particles' precession, the researchers could definitively identify the length of time it took them to tunnel through the barrier.
To construct their barrier, the scientists cooled about 8,000 rubidium atoms to a billionth of a degree above absolute zero. In this state, they form a Bose-Einstein condensate, AKA the fifth-known form of matter. When in this state, atoms slow down and can be clumped together rather than flying around independently at high speeds. (We've written before about a Bose-Einstein experiment in space.)
Using a laser, the researchers pushed about 2,000 rubidium atoms together in a barrier about 1.3 micrometers thick, endowing it with a pseudo-magnetic field. Compared to a single rubidium atom, this is a very thick wall, comparable to a half a mile deep if you yourself were a foot thick.
With the wall prepared, a second laser nudged individual rubidium atoms toward it. Most of the atoms simply bounced off the barrier, but about 3 percent of them went right through as hoped. Precise measurement of their precession produced the result: It took them 0.61 milliseconds to get through.
Reactions to the study
Scientists not involved in the research find its results compelling.
"This is a beautiful experiment," remarked Igor Litvinyuk of Griffith University in Australia. "Just to do it is a heroic effort." Drew Alton of Augustana University in South Dakota tells Live Science, "The experiment is a breathtaking technical achievement."
What makes the researchers' results so exceptional is their unambiguity. Says Chad Orzel at Union College in New York, "Their experiment is ingeniously constructed to make it difficult to interpret as anything other than what they say." He calls the research, "one of the best examples you'll see of a thought experiment made real." Litvinyuk agrees: "I see no holes in this."
As for the researchers themselves, enhancements to their experimental apparatus are underway to help them learn more. "We're working on a new measurement where we make the barrier thicker," Steinberg said. In addition, there's also the interesting question of whether or not that 0.61-millisecond trip occurs at a steady rate: "It will be very interesting to see if the atoms' speed is constant or not."
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Our hearts beat at a resting rate of 60 to 100 beats per minute. Lots of other things pulse, too. The colors we see and the pitches we hear, for example, are due to the different wave frequencies ("pulses") of light and sound waves.
Now, a study in the journal Geoscience Frontiers finds that Earth itself has a pulse, with one "beat" every 27.5 million years. That's the rate at which major geological events have been occurring as far back as geologists can tell.
A planetary calendar has 10 dates in red
Credit: Jagoush / Adobe Stock
According to lead author and geologist Michael Rampino of New York University's Department of Biology, "Many geologists believe that geological events are random over time. But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random."
The new study is not the first time that there's been a suggestion of a planetary geologic cycle, but it's only with recent refinements in radioisotopic dating techniques that there's evidence supporting the theory. The authors of the study collected the latest, best dating for 89 known geologic events over the last 260 million years:
- 29 sea level fluctuations
- 12 marine extinctions
- 9 land-based extinctions
- 10 periods of low ocean oxygenation
- 13 gigantic flood basalt volcanic eruptions
- 8 changes in the rate of seafloor spread
- 8 times there were global pulsations in interplate magmatism
The dates provided the scientists a new timetable of Earth's geologic history.
Tick, tick, boom
Credit: New York University
Putting all the events together, the scientists performed a series of statistical analyses that revealed that events tend to cluster around 10 different dates, with peak activity occurring every 27.5 million years. Between the ten busy periods, the number of events dropped sharply, approaching zero.
Perhaps the most fascinating question that remains unanswered for now is exactly why this is happening. The authors of the study suggest two possibilities:
"The correlations and cyclicity seen in the geologic episodes may be entirely a function of global internal Earth dynamics affecting global tectonics and climate, but similar cycles in the Earth's orbit in the Solar System and in the Galaxy might be pacing these events. Whatever the origins of these cyclical episodes, their occurrences support the case for a largely periodic, coordinated, and intermittently catastrophic geologic record, which is quite different from the views held by most geologists."
Assuming the researchers' calculations are at least roughly correct — the authors note that different statistical formulas may result in further refinement of their conclusions — there's no need to worry that we're about to be thumped by another planetary heartbeat. The last occurred some seven million years ago, meaning the next won't happen for about another 20 million years.
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How Apple and Nike have branded your brain | Your Brain on Money | Big Think youtu.be
Brands can manipulate our brains in surprisingly profound ways. They can change how we conceptualize ourselves and how we broadcast our identities out to the social world. They can make us feel emotions that have nothing to do with the functions of their products. And they can even sort us into tribes.
To grasp the power of brands, look to Apple. In the 1990s, the company was struggling to compete with Microsoft over the personal computer market. Despite flirting with bankruptcy in the mid-1990s, Apple turned itself around to eventually become the most valuable company in the world.
That early-stage success wasn't due to superior products.
"People talk about technology, but Apple was a marketing company," John Sculley, a former Apple marketing executive, told The Guardian in 1997. "It was the marketing company of the decade."
So, how exactly does branding make people willing to wait hours in line to buy a $1,000 smartphone, or pay exorbitant prices for a pair of sneakers?
Branding and the brain
For more than a century, brands have capitalized on the fact that effective marketing is much more than simply touting the merits of a product. Some ads have nothing to do with the product at all. In 1871, for example, Pearl Tobacco started advertising their cigarettes through branded posters and trading cards that featured exposed women, a trend that continues to this day.
It's crude, sure. But research shows that it's also remarkably effective, even on monkeys. Why? The answer seems to center on how our brains pay special attention to information from the social world.
"In theory, ads that associate sex or status with specific brands or products activate the brain mechanisms that prioritize social information, and turning on this switch may bias us toward the product," wrote neuroscience professor Michael Platt for Scientific American.
Brands can burrow themselves deep into our subconscious. Through ad campaigns, brands can form a web of associations and memories in our brains. When these connections are robust and positive, it can change our behavior, nudging us to make "no-brainer" purchases when we encounter the brand at the store.
Nike storeThamKC
It's a marketing principle that's related to the work of Daniel Kahneman, a psychologist and economist who won the 2002 Nobel Memorial Prize in Economic Sciences. In his book "Thinking Fast and Slow", Kahneman separates thinking into two broad categories, or systems:
- System 1 is fast and automatic, requiring little effort or voluntary control.
- System 2 is slow and requires subjective deliberation and logic.
Brands that tap into "system 1" are likely to dominate the competition. After all, it's far easier for us as consumers to automatically reach for a familiar brand than it is to analyze all of the available information and make an informed choice. Still, the most successful brands can have an even deeper impact on our psychology, one that causes us to conceptualize them as something like a family member.
A peculiar relationship with brands
Apple has one of the most loyal customer bases in the world, with its brand loyalty hitting an all-time high earlier this year, according to a SellCell survey of more than 5,000 U.S.-based smartphone users.
Qualitatively, how does that loyalty compare to Samsung users? To find out, Platt and his team conducted a study in which functional magnetic resonance imaging scanned the brains of Samsung and Apple users as they viewed positive, negative, and neutral news about each company. The results revealed stark differences between the two groups, as Platt wrote in "The Leader's Brain":
"Apple users showed empathy for their own brand: The reward-related areas of the brain were activated by good news about Apple, and the pain and negative feeling parts of the brain were activated by bad news. They were neutral about any kind of Samsung news. This is exactly what we see when people empathize with other people—particularly their family and friends—but don't feel the joy and pain of people they don't know."
Meanwhile, Samsung users didn't show any significant pain- or pleasure-related brain activity when they saw good or bad news about the company.
"Interestingly, though, the pain areas were activated by good news about Apple, and the reward areas were activated by bad news about the rival company—some serious schadenfreude, or "reverse empathy," Platt wrote.
The results suggest a fundamental difference between the brands: Apple has formed strong emotional and social connections with consumers, Samsung has not.
Brands and the self
Does having a strong connection with a brand justify paying higher prices for their products? Maybe. You could have a strong connection with Apple or Nike and simultaneously think the quality of their products justifies the price.
But beyond product quality lies identity. People have long used objects and clothing to express themselves and signal their affiliation with groups. From prehistoric seashell jewelry to Air Jordans, the things people wear and associate with signal a lot of information about how they conceptualize themselves.
Since the 1950s, researchers have examined the relationship between self-image and brand preferences. This body of research has generally found that consumers tend to prefer brands whose products fit well with their self-image, a concept known as self-image congruity.
By choosing brands that don't disrupt their self-image, consumers are able not only to express themselves personally, but also broadcast a specific version of themselves into the social world. That might sound self-involved. But on the other hand, humans are social creatures who use information from the social world to make decisions, so it's virtually impossible for us not to make inferences about people based on how they present themselves.
Americus Reed II, a marketing professor at the University of Pennsylvania, told Big Think:
"When I make choices about different brands, I'm choosing to create an identity. When I put that shirt on, when I put that shirt on — those jeans, that hat — someone is going to form an impression about what I'm about. So, if I'm choosing Nike over Under Armour, I'm choosing a kind of different way to express affiliation with sport. The Nike thing is about performance. The Under Armour thing is about the underdog. I have to choose which of these different conceptual pathways is most consistent with where I am in my life."
Making smarter decisions
Brands may have some power over us when we're facing a purchasing decision. So, considering brands aren't going away, what can we do to make better choices? The best strategy might be to slow down and try to avoid making "automatic" purchasing decisions that are characteristic of Kahneman's fast "system 1" mode of thinking.
"I think it's important to always pause and think a little bit about, "Okay, why am I buying this product?" Platt said.
As for getting out of the brand game altogether? Good luck.
"I've heard lots of people push back and say, "I'm not into brands,"" Reed II said. "I take a very different view. In some senses, they're not doing anything different than what someone who affiliates with a brand is doing. They have a brand. It's just an anti-brand brand."
