NASA-funded scientist says 'MEGA drive' could enable interstellar travel
The drive would provide enough thrust for a spacecraft to travel near the speed of light using only electricity, says physicist Jim Woodward.
- The thrust system utilizes piezoelectric crystals, which vibrate extremely rapidly when exposed to electric current.
- Early tests have yielded mixed results, but Woodward and his colleagues say a recent breakthrough related to the design of the thruster mount greatly increased thrust.
- Independent teams of scientists will likely test Woodward's design after the pandemic.
From health concerns to funding, there's no shortage of obstacles preventing humans from traveling beyond our solar system. But the main obstacle is propulsion: Our spacecraft are simply too slow and too reliant on fuel to realistically make a voyage to Alpha Centauri, the closest star to our Sun.
So, what do we need? Something like a reactionless drive — an engine that moves a spacecraft without exhausting a finite stock of propellant. So far, such a device only exists in science fiction. But for the past few decades, physicist Jim Woodward has been trying to change that.
The 79-year-old physics professor has developed what a thruster design that he hopes will serve as a proof of concept for how humans can someday achieve interstellar travel. Called the Mach-effect gravitational assist (MEGA) drive, the device only requires a source of electricity to achieve thrust.
Early tests have shown mixed results. Woodward himself was only able to demonstrate miniscule amounts of thrust, while other teams reported little to no thrust when trying to replicate his experiments. Still, the design intrigued NASA enough to award Woodward $625,000 in funding between 2017 and 2018.
What's more, in 2019 Woodward and his collaborator and fellow physicist Hal Fearn reported a major breakthrough after redesigning the thruster's mount — a tweak that produced "more than 100 micronewtons, orders of magnitude larger than anything Woodward had ever built before," as a recent feature in Wired notes.
(To be sure, the level of thrust we're talking about is barely enough to visibly move an object across a table. But if the results are confirmed, it would suggest the technology could be scaled up.)
A heterodox view of inertia
Woodward's system is based on ideas that 19th-century physicist Ernst Mach proposed about inertia, which is an object's tendency to stay at rest unless acted upon.
In simple terms, Mach's principle argues that distant matter causes local inertial effects. So, a star in a far away galaxy has some effect on the inertia you encounter when you push a shopping cart. That's the idea, anyway. (Woodward gives a comprehensive breakdown of his views on Mach's principle in this blog post.)
In the 20th century, Albert Einstein incorporated Mach's ideas into his theory of general relativity, essentially arguing that gravity and inertia are fundamentally linked. But the broader physics community later rejected this view of inertia, largely because of a 1961 paper that showed inertia to be unrelated to the gravitational influence of distant matter.
Still, Woodward believes Einstein had it right all along, and that, under this framework of inertia, it's possible to develop propulsion systems that require only an electrical charge, not fuel. The key element of his thruster is a stack of piezoelectric crystals, which produces an alternating electric field when voltage is applied to it, as Woodward explained:
"Piezoelectric crystals are electromechanical devices, which means that when you apply the voltage, they mechanically expand & contract depending upon the sign of the voltage. So by applying a voltage, you're causing an E/c² energy fluctuation in the stack no matter what they do mechanically, and you're also producing an acceleration because of the changing dimensions of the stack due due to electromechanical effects, which also causes the acceleration required couple the device to the large gravitational field."
"The trick is timing the energy fluctuations and mechanical oscillations correctly, which requires using two frequencies — at the first and second harmonics, and it's the second harmonic that actually produces thrust."
Woodward and his colleagues have even drawn up plans for a spacecraft that would utilize the MEGA drive. Called the SSI Lambda, the craft would feature piezoelectric crystals and a small nuclear reactor to produce electricity.
"The SSI Lambda probe using MEGA drive thrusters is a truly propellantless-propulsion spacecraft," the team wrote of the design in its report to NASA. "It can travel at speeds up to the speed of light in a vacuum with only consumption of electric power. No other method for travelling to the stars and braking into the target system has been put forward to date, which also has credible physics to back it up."
After the COVID-19 pandemic settles down, other scientists and engineers hope to put Woodward's designs to the test. The results of those experiments should reveal whether he's onto something. To some experts in the field, the odds are slim. But that doesn't mean it's not worth investigating.
"I'd say there's between a 1-in-10 and 1-in-10,000,000 chance that it's real, and probably toward the higher end of that spectrum," Mike McDonald, an aerospace engineer at the Naval Research Laboratory in Maryland, told Wired. "But imagine that one chance; that would be amazing. That's why we do high-risk, high-reward work. That's why we do science."
- New space dangers found by NASA in astronaut blood - Big Think ›
- Michio Kaku forecasts the future of space travel - Big Think ›
- Space travel could create language unintelligible to people on Earth ... ›
Join Radiolab's Latif Nasser at 1pm ET on Monday as he chats with Malcolm Gladwell live on Big Think.
University of Utah research finds that men are especially well suited for fisticuffs.
- With males having more upper-body mass than women, a study looks to find the reason.
- The study is based on the assumption that men have been fighters for so long that evolution has selected those best-equipped for the task.
- If men fought other men, winners would have survived and reproduced, losers not so much.
Built for mayhem<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMzk4NTQ2OX0.my6nML12F3fEQu3H4G0BScdqgaMZkRQHxgyj-Cmjmzk/img.jpg?width=980" id="906fc" class="rm-shortcode" data-rm-shortcode-id="dd77af7a881631355ed8972437846394" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers are, of course, talking averages here, not stating a rule: There are plenty of accomplished female pugilists, as well as lots of males who have no idea how to throw a punch.</p><p>Even so, says co-author <a href="https://www.wofford.edu/academics/majors-and-programs/biology/faculty-and-staff" target="_blank">Jeremy Morris</a> says, "The general approach to understanding why sexual dimorphism evolves is to measure the actual differences in the muscles or the skeletons of males and females of a given species, and then look at the behaviors that might be driving those differences."</p><p>Carrier has been interested in the idea that millennia of male fighting has shaped certain structures in male bodies. Previous research has reinforced his hunch:</p> <ul> <li><a href="https://jeb.biologists.org/content/216/2/236" target="_blank">When a hand is formed into a fist, its structure is self-protective</a>.</li> <li><a href="https://unews.utah.edu/flat-footed-fighters/" target="_blank">Heels planted firmly on the ground augment upper-body power</a>.</li> <li><a href="https://www.ncbi.nlm.nih.gov/pubmed/24909544" target="_blank">A study examined facial bone structure as being especially well-suited for taking a punch</a>.</li> </ul> <p>(That last one is our favorite. Do you know the German word "<a href="https://www.urbandictionary.com/define.php?term=Backpfeifengesicht" target="_blank">backpfeifengesicht</a>?" It's an adjective describing "a face that badly needs a punching.")</p><p>"One of the predictions that comes out of those," asserts Carrier, "is if we are specialized for punching, you might expect males to be particularly strong in the muscles that are associated with throwing a punch."</p>
Testing the theory<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIzMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNzMxMTE2MH0.UXJICMy57UPYUWskhK98alctOrPidJL9yxMkz3HDQrM/img.jpg?width=980" id="98718" class="rm-shortcode" data-rm-shortcode-id="b12287684ac3e740b70392e6433a6b8f" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers measured the punching — and spear-throwing — force of 20 men and 19 women. The assumption was that early humans were punchers <em>and</em> spear-throwers.</p><p>Prior to testing, each participant had filled out an activity questionnaire so that "we weren't getting couch potatoes, we were getting people that were very fit and active," says Morris.</p><p>For punching, participants operated a hand crank that required movement similar to throwing a haymaker. The purpose of the hand crank was to spare participants any damage that might be inflicted on their fists by throwing actual punches. Subjects were also measured pulling a line forward over their heads to assess their strength at throwing a spear.</p><p>Even though all of the participants, male and female, were routinely fit, the average power of males was assessed as being 162% greater than females. There were no gender differences in throwing strength recorded. Other untested, though presumably likely, hand-to-hand combat activities come to mind including tackling, clubbing, running, kicking, scratching, and biting.</p><p>Carrier's takeaway: "This is a dramatic example of sexual dimorphism that's consistent with males becoming more specialized for fighting, and males fighting in a particular way, which is throwing punches."</p>
Boys will be boys<p>It, er, strikes us as odd that, even in science fiction — hi-tech weaponry notwithstanding — the hero <em>is</em> going to wind up duking it out with some bad guy, or alien, in the climactic battle. What is it about men punching, anyway? Are they more sexually attractive? The study suggests so:</p><p style="margin-left: 20px;"><em>The results of this study add to a set of recently identified characters indicating that sexual selection on male aggressive performance has played a role in the evolution of the human musculoskeletal system and the evolution of sexual dimorphism in hominins.</em></p><p>It's tough to contribute to the gene pool after being killed in battle.</p><p>Also, while the authors aren't <em>quite</em> saying that males' historical fighting role is mandated by biology and not by social expectations, neither are they quite <em>not</em> saying it.</p><p>As Carrier explain to <a href="https://attheu.utah.edu/facultystaff/carrier-punch/" target="_blank">theU</a>: "Human nature is also characterized by avoiding violence and finding ways to be cooperative and work together, to have empathy, to care for each other, right? There are two sides to who we are as a species. If our goal is to minimize all forms of violence in the future, then understanding our tendencies and what our nature really is, is going to help."</p>
Innovators don't ignore risk; they are just better able to analyze it in uncertain situations.
The Labour Economics study suggests two potential reasons for the increase: corruption and increased capacity.
Cool hand rebuke<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQyMTIyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NjY1NTYyOH0.0MCPKN3If94mYCNf3mMNrnTvJXjXN_bKLhgk9203EXk/img.jpg?width=917&coordinates=0%2C0%2C0%2C0&height=453" id="1627b" class="rm-shortcode" data-rm-shortcode-id="6d76421ba1ea0de4b09956b97e80c384" data-rm-shortcode-name="rebelmouse-image" />
A chart showing prison population rates (per 100,000 people) in 2018. The United States has the highest rate of incarceration in the world.