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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."
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What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.
- Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
- That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
- We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
The inherent worth of all human beings<p>Human dignity is the inherent worth of each individual human being. Recognizing human dignity means respecting human beings' special value—value that sets us apart from other animals; value that is intrinsic and cannot be lost.</p> <p>Liberalism—the broad political philosophy that organizes society around liberty, justice, and equality—is rooted in the idea of human dignity. Liberalism assumes each of our lives, plans, and preferences have some unimpeachable value, not because of any objective evaluation or contribution to a greater good, but simply because they belong to a human being. We are human, and therefore deserving of a baseline level of respect. </p> <p>Because so many of us take human dignity for granted—just a fact of our humanness—it's usually only when someone's dignity is ignored or violated that we feel compelled to talk about it. </p> <p>But human dignity means more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose—a freedom that can be hampered by restrictive social institutions or the tyranny of the majority. The liberal ideal of the good society is not just peaceful but also pluralistic: It is a society in which we respect others' right to think and live differently than we do.</p>
From the 19th century to today<p>With <a href="https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&content=human+dignity&corpus=26&smoothing=3&direct_url=t1%3B%2Chuman%20dignity%3B%2Cc0" target="_blank" rel="noopener noreferrer">Google Books Ngram Viewer</a>, we can chart mentions of human dignity from 1800-2019.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg0ODU0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1MTUwMzE4MX0.bu0D_0uQuyNLyJjfRESNhu7twkJ5nxu8pQtfa1w3hZs/img.png?width=980" id="7ef38" class="rm-shortcode" data-rm-shortcode-id="9974c7bef3812fcb36858f325889e3c6" data-rm-shortcode-name="rebelmouse-image" />
American novelist, writer, playwright, poet, essayist and civil rights activist James Baldwin at his home in Saint-Paul-de-Vence, southern France, on November 6, 1979.
Credit: Ralph Gatti/AFP via Getty Images
The future of dignity<p>Around the world, people are still working toward the full and equal recognition of human dignity. Every year, new speeches and writings help us understand what dignity is—not only what it looks like when dignity is violated but also what it looks like when dignity is honored. In his posthumous essay, Congressman Lewis wrote, "When historians pick up their pens to write the story of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war."</p> <p>The more we talk about human dignity, the better we understand it. And the sooner we can make progress toward a shared vision of peace, freedom, and mutual respect for all. </p>
With just a few strategical tweaks, the Nazis could have won one of World War II's most decisive battles.
- The Battle of Britain is widely recognized as one of the most significant battles that occurred during World War II. It marked the first major victory of the Allied forces and shifted the tide of the war.
- Historians, however, have long debated the deciding factor in the British victory and German defeat.
- A new mathematical model took into account numerous alternative tactics that the German's could have made and found that just two tweaks stood between them and victory over Britain.
Two strategic blunders<p>Now, historians and mathematicians from York St. John University have collaborated to produce <a href="http://www-users.york.ac.uk/~nm15/bootstrapBoB%20AAMS.docx" target="_blank">a statistical model (docx download)</a> capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different. </p><p>Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.</p><p>"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a <a href="https://www.york.ac.uk/news-and-events/news/2020/research/mathematicians-battle-britain-what-if-scenarios/" target="_blank">statement</a>. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.</p><p>"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."</p><p>Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.</p><p>Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.</p>
A tool for understanding history<p>This technique, said co-author Niall Mackay, "demonstrates just how finely-balanced the outcomes of some of the biggest moments of history were. Even when we use the actual days' events of the battle, make a small change of timing or emphasis to the arrangement of those days and things might have turned out very differently."</p><p>The researchers also claimed that their technique could be applied to other uncertain historical events. "Weighted bootstrapping can provide a natural and intuitive tool for historians to investigate unrealized possibilities, informing historical controversies and debates," said Mackay.</p><p>Using this technique, researchers can evaluate other what-ifs and gain insight into how differently influential events could have turned out if only the slightest things had changed. For now, at least, we can all be thankful that Hitler underestimated Britain's grit.</p>
A new study shows our planet is much closer to the supermassive black hole at the galaxy's center than previously estimated.
Arrows on this map show position and velocity data for the 224 objects utilized to model the Milky Way Galaxy. The solid black lines point to the positions of the spiral arms of the Galaxy. Colors reflect groups of objects that are part of the same arm, while the background is a simulation image.
Apple sold its first iPod in 2001, and six years later it introduced the iPhone, which ushered in a new era of personal technology.