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Is This The Secret Behind the Mysterious Em Drive?
The secret behind the Em Drive’s thrust, which is real, may be in the long-discarded pilot wave theory.
It’s the law. Newton’s third, specifically: “For every action, there is an equal and opposite reaction.” It’s the basis of existing space propulsion systems: As fuel mixes with oxygen, exhaust molecules shoot out from the back of a rocket, the speed of their acceleration matched by the rocket’s forward movement, or thrust. So then, how could Roger Shawyer’s seemingly impossible Em Drive actually be creating thrust without fuel, a clear violation of Newton’s law? And yet it does. The answer to this mystery, a new paper published in Journal of Applied Physical Science International suggests, may lie in a relatively obscure and controversial interpretation of quantum physics: pilot wave theory.
NASA's test setup (NASASPACEFLIGHT)
Pilot wave theory conflicts with one of quantum physicists’ most deeply held assumptions, but it would explain the Em Drive, and maybe even allow engineers to increase its power. Not to mention reshape thinking about quantum mechanics altogether if the drive winds up being compelling evidence of pilot wave theory’s validity.
At issue is the notion of a probabilistic universe in which particles play out all possible states simultaneously in superposition, reaching a fixed state only at the moment they’re observed. However weird this seems, the math does work out — quantum physicist Seth Lloyd of MIT says, “Quantum mechanics is just counterintuitive and we just have to suck it up.” This so-called “Copenhagen interpretation” is largely accepted among physicists, though, it must be said, not universally. Einstein famously criticized the idea, saying, “God does not play dice with the universe,” and his biographer, Abraham Pais, once said, “I recall that during one walk Einstein suddenly stopped, turned to me and asked whether I really believed that the moon exists only when I look at it.”
Solvay Conference, 1927
The pilot wave theory — also known as the Broglie-Bohm theory and Bohmian mechanics — was first proposed by Louis de Broglie in 1927 at the landmark Solvay Conference, a gathering of physicists’ including Albert Einstein, Werner Heisenberg, Neils Bohr, and Erwin Schrödinger. It rejects probabilistic particles. In pilot wave theory, particles have a definite location even when unobserved. The theory asserts that their position and direction is guided, or “piloted,” by a constantly changing quantum wave function that is itself continuously being influenced by other particles and waves. The theory holds that particles move to areas of higher intensity or a stronger energy density in the wave. The wave’s effect on a particle at any given moment depends on the wave’s current state, and it’s difficult to accurately predict that state in light of all the possible influencing factors. Therefore, the wave is subject to the Schrödinger equation in that its current state is only detectable as it’s observed. (Schrödinger considered the Copenhagen view ridiculous, and offered his famously nutty cat thought experiment as proof.)
Pilot wave theory does makes more intuitive sense, and it explains weird quantum behaviors as well as the Copenhagen view does. For example, in pilot wave theory, “spooky action at a distance” is explained by one huge, complex and extended wave influencing two non-contiguous particles at the same time. A study of fluidic behavior by a team in Paris produced results amazingly consistent with the wave-or-particle behavior seen in the classic Copenhagen single- and double-slit experiments.
It’s unclear, historically, exactly what arguments at the Solvay Conference led to a greater adoption of the Copenhagen view, but a series of now-discredited experiments by mathematician John von Neumann in 1932 effectively killed support for theory. That is, until it was revived in 1952 by David Bohm, with the encouragement of Einstein. The man who discredited von Neumann’s work and author of the Bell theorem, John Stewart Bell, wrote of pilot wave theory in 1986 that it, “seems to me so natural and simple, to resolve the wave-particle dilemma in such a clear and ordinary way, that it is a great mystery to me that it was so generally ignored.”
So how does pilot wave theory explain the mysterious workings of the Em Drive? Here's what it says on emdrive.com, “Thrust is produced by the amplification of the radiation pressure of an electromagnetic wave propagated through a resonant waveguide assembly.” The new work by Portuguese researchers José Croca and Paulo Castro of the University of Lisbon’s Centre for Philosophy of Sciences takes a closer look at that electromagnetic wave. The researchers describe how they modeled the waves produced by the Em Drive’s asymmetrical cone, or fustrum. They found that the wave, like the fustrum, would be asymmetrical, with some regions exhibiting a higher magnetic density to which the Em Drive would be attracted, and thus move. The team says that this exonerates the Em Drive from violating Newton’s law, telling ScienceAlert, "We have found that applying a pilot wave theory to NASA's EM drive frustum, we could explain its thrust without involving any external action applied to the system, as Newton's third law would require.” In fact, NASA also wondered if pilot wave theory could be at work when it verified the thrust being produced by the Em Drive in 2016.
“The supporting physics model used to derive a force based on operating conditions in the test article can be categorized as a nonlocal hidden-variable theory, or pilot-wave theory for short.”
While so far the Em Drive’s pilot wave behavior has only been seen in the Paris team’s models, they tell ScienceAlert that, “we have also devised an experiment to detect and modulate subquantum waves."
The researchers may also have an idea how to increase the so-far tiny amount of thrust produced by Em Drives: By changing the shape of its fustrum, and thus the resulting electromagnetic field, noting “We have seen that the effect could be enhanced using a different shape for the frustum. In fact, a trumpet exponential form is expected to increase the thrust.”
So much for rest in peace.
- Australian scientists found that bodies kept moving for 17 months after being pronounced dead.
- Researchers used photography capture technology in 30-minute intervals every day to capture the movement.
- This study could help better identify time of death.
We're learning more new things about death everyday. Much has been said and theorized about the great divide between life and the Great Beyond. While everyone and every culture has their own philosophies and unique ideas on the subject, we're beginning to learn a lot of new scientific facts about the deceased corporeal form.
An Australian scientist has found that human bodies move for more than a year after being pronounced dead. These findings could have implications for fields as diverse as pathology to criminology.
Dead bodies keep moving
Researcher Alyson Wilson studied and photographed the movements of corpses over a 17 month timeframe. She recently told Agence France Presse about the shocking details of her discovery.
Reportedly, she and her team focused a camera for 17 months at the Australian Facility for Taphonomic Experimental Research (AFTER), taking images of a corpse every 30 minutes during the day. For the entire 17 month duration, the corpse continually moved.
"What we found was that the arms were significantly moving, so that arms that started off down beside the body ended up out to the side of the body," Wilson said.
The researchers mostly expected some kind of movement during the very early stages of decomposition, but Wilson further explained that their continual movement completely surprised the team:
"We think the movements relate to the process of decomposition, as the body mummifies and the ligaments dry out."
During one of the studies, arms that had been next to the body eventually ended up akimbo on their side.
The team's subject was one of the bodies stored at the "body farm," which sits on the outskirts of Sydney. (Wilson took a flight every month to check in on the cadaver.)Her findings were recently published in the journal, Forensic Science International: Synergy.
Implications of the study
The researchers believe that understanding these after death movements and decomposition rate could help better estimate the time of death. Police for example could benefit from this as they'd be able to give a timeframe to missing persons and link that up with an unidentified corpse. According to the team:
"Understanding decomposition rates for a human donor in the Australian environment is important for police, forensic anthropologists, and pathologists for the estimation of PMI to assist with the identification of unknown victims, as well as the investigation of criminal activity."
While scientists haven't found any evidence of necromancy. . . the discovery remains a curious new understanding about what happens with the body after we die.
Metal-like materials have been discovered in a very strange place.
- Bristle worms are odd-looking, spiky, segmented worms with super-strong jaws.
- Researchers have discovered that the jaws contain metal.
- It appears that biological processes could one day be used to manufacture metals.
The bristle worm, also known as polychaetes, has been around for an estimated 500 million years. Scientists believe that the super-resilient species has survived five mass extinctions, and there are some 10,000 species of them.
Be glad if you haven't encountered a bristle worm. Getting stung by one is an extremely itchy affair, as people who own saltwater aquariums can tell you after they've accidentally touched a bristle worm that hitchhiked into a tank aboard a live rock.
Bristle worms are typically one to six inches long when found in a tank, but capable of growing up to 24 inches long. All polychaetes have a segmented body, with each segment possessing a pair of legs, or parapodia, with tiny bristles. ("Polychaeate" is Greek for "much hair.") The parapodia and its bristles can shoot outward to snag prey, which is then transferred to a bristle worm's eversible mouth.
The jaws of one bristle worm — Platynereis dumerilii — are super-tough, virtually unbreakable. It turns out, according to a new study from researchers at the Technical University of Vienna, this strength is due to metal atoms.
Metals, not minerals
Fireworm, a type of bristle wormCredit: prilfish / Flickr
This is pretty unusual. The study's senior author Christian Hellmich explains: "The materials that vertebrates are made of are well researched. Bones, for example, are very hierarchically structured: There are organic and mineral parts, tiny structures are combined to form larger structures, which in turn form even larger structures."
The bristle worm jaw, by contrast, replaces the minerals from which other creatures' bones are built with atoms of magnesium and zinc arranged in a super-strong structure. It's this structure that is key. "On its own," he says, "the fact that there are metal atoms in the bristle worm jaw does not explain its excellent material properties."
Just deformable enough
Credit: by-studio / Adobe Stock
What makes conventional metal so strong is not just its atoms but the interactions between the atoms and the ways in which they slide against each other. The sliding allows for a small amount of elastoplastic deformation when pressure is applied, endowing metals with just enough malleability not to break, crack, or shatter.
Co-author Florian Raible of Max Perutz Labs surmises, "The construction principle that has made bristle worm jaws so successful apparently originated about 500 million years ago."
Raible explains, "The metal ions are incorporated directly into the protein chains and then ensure that different protein chains are held together." This leads to the creation of three-dimensional shapes the bristle worm can pack together into a structure that's just malleable enough to withstand a significant amount of force.
"It is precisely this combination," says the study's lead author Luis Zelaya-Lainez, "of high strength and deformability that is normally characteristic of metals.
So the bristle worm jaw is both metal-like and yet not. As Zelaya-Lainez puts it, "Here we are dealing with a completely different material, but interestingly, the metal atoms still provide strength and deformability there, just like in a piece of metal."
Observing the creation of a metal-like material from biological processes is a bit of a surprise and may suggest new approaches to materials development. "Biology could serve as inspiration here," says Hellmich, "for completely new kinds of materials. Perhaps it is even possible to produce high-performance materials in a biological way — much more efficiently and environmentally friendly than we manage today."
Dealing with rudeness can nudge you toward cognitive errors.
- Anchoring is a common bias that makes people fixate on one piece of data.
- A study showed that those who experienced rudeness were more likely to anchor themselves to bad data.
- In some simulations with medical students, this effect led to higher mortality rates.
Cognitive biases are funny little things. Everyone has them, nobody likes to admit it, and they can range from minor to severe depending on the situation. Biases can be influenced by factors as subtle as our mood or various personality traits.
A new study soon to be published in the Journal of Applied Psychology suggests that experiencing rudeness can be added to the list. More disturbingly, the study's findings suggest that it is a strong enough effect to impact how medical professionals diagnose patients.
Life hack: don't be rude to your doctor
The team of researchers behind the project tested to see if participants could be influenced by the common anchoring bias, defined by the researchers as "the tendency to rely too heavily or fixate on one piece of information when making judgments and decisions." Most people have experienced it. One of its more common forms involves being given a particular value, say in negotiations on price, which then becomes the center of reasoning even when reason would suggest that number should be ignored.
It can also pop up in medicine. As co-author Dr. Trevor Foulk explains, "If you go into the doctor and say 'I think I'm having a heart attack,' that can become an anchor and the doctor may get fixated on that diagnosis, even if you're just having indigestion. If doctors don't move off anchors enough, they'll start treating the wrong thing."
Lots of things can make somebody more or less likely to anchor themselves to an idea. The authors of the study, who have several papers on the effects of rudeness, decided to see if that could also cause people to stumble into cognitive errors. Past research suggested that exposure to rudeness can limit people's perspective — perhaps anchoring them.
In the first version of the study, medical students were given a hypothetical patient to treat and access to information on their condition alongside an (incorrect) suggestion on what the condition was. This served as the anchor. In some versions of the tests, the students overheard two doctors arguing rudely before diagnosing the patient. Later variations switched the diagnosis test for business negotiations or workplace tasks while maintaining the exposure to rudeness.
Across all iterations of the test, those exposed to rudeness were more likely to anchor themselves to the initial, incorrect suggestion despite the availability of evidence against it. This was less significant for study participants who scored higher on a test of how wide of a perspective they tended to have. The disposition of these participants, who answered in the affirmative to questions like, "Before criticizing somebody, I try to imagine how I would feel if I were in his/her place," was able to effectively negate the narrowing effects of rudeness.
What this means for you and your healthcare
The effects of anchoring when a medical diagnosis is on the line can be substantial. Dr. Foulk explains that, in some simulations, exposure to rudeness can raise the mortality rate as doctors fixate on the wrong problems.
The authors of the study suggest that managers take a keener interest in ensuring civility in workplaces and giving employees the tools they need to avoid judgment errors after dealing with rudeness. These steps could help prevent anchoring.
Also, you might consider being nicer to people.