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.”
The new version's battery has a shorter range and a price $4,000 lower than the previous starting price.
- Tesla's new version of the Model 3 costs $45,000 and can travel 260 miles on one charge.
- The Model 3 is the best-selling luxury car in the U.S.
- Tesla still has yet to introduce a fully self-driving car, even though it once offered the capability as an option to be installed at a future date.
"It's about having employees that are empowered."
Denmark may be the birthplace of the Lego tower, but its workplace hierarchy is the flattest in the world.
According to the World Economic Forum's Global Competitiveness Report 2018, the nation tops an index measuring "willingness to delegate authority" at work, beating 139 other countries.
We all know sleeping with your ex is a bad idea, or is it?
- In the first study of its kind, researchers have found sex with an ex didn't prevent people from getting over their relationship.
- Instead of feeling worse about their breakup after a hookup, the new singles who attempted sexual contact with their ex reported feeling better afterwards.
- The findings suggest that not every piece of relationship advice is to be taken at face value.
Want a happy, satisfying relationship? Psychologists say the best way is to learn to take a joke.
- New research looks at how partners' attitudes toward humor affects the overall quality of a relationship.
- Out of the three basic types of people, people who love to be laughed at made for better partners.
- Fine-tuning your sense of humor might be the secret to a healthy, happy, and committed relationship.
It's hard to imagine such a number. But these images will help you try.
The Mega Millions lottery just passed $1 billion for tonight's drawing.
What does that even look like, when represented by various currencies?
It takes just 6 numbers to win. You can only, however, purchase tickets up until 10:45 ET tonight.
Tiny and efficient, these biodegradable single cells show promise as a way to target hard-to-reach cancers.
- Scientists in Germany have found a potential improvement on the idea of bacteria delivering medicine.
- This kind of microtargeting could be useful in cancer treatments.
- The microswimmers are biodegradable and easy to produce.
Metin Sitti and colleagues at the Max Planck Institute in Germany recently demonstrated that tiny drugs could be attached to individual algae cells and that those algae cells could then be directed through body-like fluid by a magnetic field.
The results were recently published in Advanced Materials, and the paper as a whole offers up a striking portrait of precision and usefulness, perhaps loosely comparable in overall quality to recent work done by The Yale Quantum Institute. It begins by noting that medicine has been attached to bacteria cells before, but bacteria can multiply and end up causing more harm than good.
A potential solution to the problem seems to have been found in an algal cell: the intended object of delivery is given a different electrical charge than the algal cell, which helps attach the object to the cell. The movement of the algae was then tested in 2D and 3D. (The study calls this cell a 'microswimmer.') It would later be found that "3D mean swimming speed of the algal microswimmers increased more than twofold compared to their 2D mean swimming speed." The study continues —
More interestingly, 3D mean swimming speed of the algal microswimmers in the presence of a uniform magnetic field in the x-direction was approximately threefolds higher than their 2D mean swimming speed.
After the 2D and 3D speed of the algal was examined, it was then tested in something made to approximate human fluid, including what they call 'human tubal fluid' (think of the fallopian tubes), plasma, and blood. They then moved to test the compatibility of the microswimmer with cervical cancer cells, ovarian cancer cells, and healthy cells. They found that the microswimmer didn't follow the path of bacteria cells and create something toxic.
The next logical steps from the study include testing this inside a living organism in order to assess the safety of the procedure. Potential future research could include examining how effective this method of drug delivery could be in targeting "diseases in deep body locations," as in, the reproductive and gastrointestinal tracts.
Our modern-day Kafka on his new novel Lake Success and the dark comedy that in 2018 pretty much writes itself
- riding the Greyhounds of hell, from New York to El Paso
- the alternate reality of hedge fund traders
Here's why the school you went to is less relevant than ever.
- Learning agility is the ability to learn new things quickly and be aware of the trends that are emerging in your industry. It's the most important job skill hiring managers should be looking for and job seekers should be putting forward, says Kelly Palmer.
- Want to test your learning agility? Answer this practice interview question: "What did you learn last week?"
- Hiring people based on the school they went to is less relevant than ever. Why? Palmer explains: "If I asked you, "Tell me about your health," and you told me you ran a marathon 10 years ago, does that really tell me what your health is like? Not really." It's what you can offer now and how agile you are that matters.
- Kelly Palmer is the author of The Expertise Economy.
SMARTER FASTER trademarks owned by The Big Think, Inc. All rights reserved.