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‘Tank’

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If you’ve got a soft spot for vintage ’80s vector-graphic video games like Star Wars and Battlezone, you’re going to love this new short film by Stu Maschwitz. So great. Also, a fantastic 20-minute video on how it was made.

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glenn
1 day ago
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Waterloo, Canada
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Kirkman
1 day ago
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Awesome short film.
Ferguson, MO, USA

A German Team Is Now Trying to Make the ‘Impossible’ EmDrive Engine

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Since the beginning of the space race over half-a-century ago, humans have walked on the moon and remotely explored the surface of two other planets in our solar system with robots. But so far, only a single spacecraft has made it to interstellar space: Voyager 1, launched in 1977, is currently speeding through the void at a blistering 40,000 miles per hour and covering about 325 million miles per year. Yet even if it was headed in the direction of Alpha Centauri, our closest stellar neighbor, it would take Voyager over 80,000 years to arrive. For a little more perspective on the timescales involved here, 80,000 years ago on Earth the first homo sapiens were spreading out of Africa into Asia.

This is all to say that from a cosmic perspective, Earth is very, very isolated. Perhaps an intuitive idea of this isolation is why our science fiction stories have always been haunted by dreams of interstellar travel, but recently physicists have started to seriously consider how to turn those fictions into reality.

In a paper presented at the Aeronautics and Astronautics Association of France’s Space Propulsion conference this week, a team of German physicists announced SpaceDrive, a research program exploring exotic propulsion mechanisms that they hope will one day make interstellar space travel a reality.

In particular, they described their research results on the EmDrive, a type of “impossible” spacecraft engine that is theoretically able to generate thrust without any propellant. It’s a bit like trying to design a Formula One race car that doesn’t need any gas and is instead powered by the driver pushing on the inside of the windshield. While the researchers didn’t crack the secret to the propellantless-engine, they did manage to create a hypersensitive measurement device and identify sources of possible false positives that will help to better characterize EmDrive experiments in the future.

Read More: The Fact and Fiction of the NASA EmDrive Paper Leak


Normal rockets are limited in their ability to provide interstellar transport because they can’t carry enough fuel to achieve velocities that would make interstellar travel feasible in human time spans. Overcoming the limitations of normal rocket propulsion systems will be necessary for interstellar travel. One leading nonreactive system is being explored by Breakthrough Starshot, which plans to use incredibly powerful lasers to accelerate thumbnail-sized chips to 20 percent the speed of light toward Alpha Centauri. Another strong candidate for nonreactive systems is the EmDrive, which could theoretically be scaled up to propel much larger spacecraft.

The EmDrive concept can be traced back to a paper written by the physicist Roger Shawyer in 2001, but it wasn’t until relatively recently that the idea gained much traction. In 2016, a group of physicists gathered at Estes Park in Colorado to discuss the feasibility of exotic propulsion systems like the EmDrive. Shortly after the meeting, a NASA paper describing an initial successful test of an EmDrive prototype was leaked. Then Chinese state media reported that it, too, had physicists researching these impossible engines who had seen positive results. It wasn’t long before 3D-printed EmDrive prototypes appeared online so that researchers and amateurs could conduct their own EmDrive tests at home.

What was once pure theory seemed to quickly be turning into a feasible reality.

The EmDrive prototype developed by NASA and described in its leaked 2016 paper basically consists of a closed copper cone mounted on an incredibly sensitive pendulum sensor that can detect even the slightest movements. The cone was then placed in a vacuum chamber and its insides were bombarded with microwaves. Incredibly, when these microwaves bounced off the walls of the cone, the pendulum registered a very small amount of thrust that varied with the power of the microwaves supplied to the device. The result was incredible because it appeared to violate the conservation of momentum, a fundamental law of physics that states for every action there is an equal and opposite reaction.

"The issue involved here is whether the experiment is seeing something real or not," Jim Woodward, a physicist at California State-Fullerton and a leading researcher on exotic propulsion mechanisms, told Motherboard after the NASA paper was leaked. "I suspect there may really be something there, but the result they're seeing can't actually be explained in terms of the theory they're proposing. So the question is: what is causing it?"

The researchers themselves broached an explanation that attempts to account for the thrust by invoking pilot wave theory. This theory explains the strange properties of quantum matter (such as entangled particles that can instantaneously influence one another) by suggesting there are ‘hidden variables’ at work that can account for perceived quantum weirdness with regular Newtonian physics—no “ spooky action at a distance” required.

The researcher’s explanation was tentative and didn’t offer a coherent model of exactly how this would work. This led to a flurry alternative explanations including a nonlocal intepretation of pilot wave theory, which keeps quantum effects in the mix, and a theory of radiation pressure posited by Shawyer which claims that microwave radiation puts pressure on the walls of the EmDrive to generate thrust. Woodward, on the other hand, offered up Mach effects as “ the only possible explanation” for the observed thrust.

According to Woodward’s Mach effect theory, when a body of mass is accelerated, some of the force applied to that body does not result in kinetic energy but is stored as potential energy in the body. While the acceleration is changing the internal energy of the body changes as well, which manifests itself as a change in the resting mass of that body. The accelerating body is essentially being squished between the force being applied in the direction of its acceleration and the push back from the rest of the material in the universe via the gravitational field.

Read More: Theoretical Physicists Are Getting Closer to Explaining How NASA’s ‘Impossible’ EmDrive Works

This mass fluctuation effect could account for the thrust observed in NASA’s EmDrive prototype. If the microwaves propagating in the EmDrive cone are applying thrust force to the material that the cone is made of, then you might explain the trust generated this way. “In my view, it’s the only physics that I know and trust to not involve wishful thinking and magical fields,” Woodward told me when we spoke after the NASA leak.

There’s a strong case to be made for Woodward’s Mach-Effect theory, but a far more obvious explanation was that the observed thrust was simply due to an error. In their paper, the NASA researchers strove to eliminate all the major sources of error, such as electromagnetic interference, vibration or thermal expansion of the cone. Still, a team of German physicists are working on a super precise testing facility that will hopefully put to rest the question of whether the observed thrust was just an error.

As detailed in the paper presented by the researchers this week, over the past four years they have designed a sophisticated balance that is placed in a vacuum chamber and measures the movement of an EmDrive prototype using lasers. NASA’s EmDrive only produced a few micro-Newtons of thrust, but this measurement system is able to measure the degree of thrust at a sub-micro-Newton level.

The prototype EmDrive built by the German researchers was a copper cavity with the same dimensions as the prototype tested by NASA in 2016. Although they limited the power supplied to the EmDrive to just 2 watts, their sensors were able to measure roughly 4 micro-Newtons of thrust. Extrapolating from this data, that means that their EmDrive prototype had a thrust-to-power ratio of about 2 milliNewtons per kilowatt, which is almost twice the thrust-to-power ratio achieved at NASA (1.3 milliNewtons per kilowatt).

Yet the German researchers noted that when they changed the direction that the EmDrive was facing, the direction of the thrust changed, but the level of thrust did not, even when the EmDrive was oriented in such a way that any applied power should produce zero thrust.

“This clearly indicates that the ‘thrust’ is not coming from the EmDrive, but some electromagnetic interaction,” the researchers wrote in their paper. “Although we used twisted or coaxial cables as much as possible, some magnetic fields will eventually leak through our cables and connectors.”

When they calculated the forces resulting from a combination of Earth’s magnetic field, the length of their cables and the electric current flowing through them, they found that the result was equal to a few micro-Newtons, which is comparable to the ‘thrust’ they had observed in the vacuum chamber. “We therefore suspect that the interaction of the power feeding for the amplifier with the Earth’s magnetic field masked any real thrusts that could be below our observed value,” they wrote. In a future test, the researchers said they planned to add Mu-metal sheets to the setup that would shield the device from these unwanted outside electromagnetic influences. Yet as they note in their paper, this type of shielding was not used during the NASA experiments.

Although the German researchers did not manage to demonstrate thrust with their EmDrive experiments, they did help identify a possible source of false positives in EmDrive experiments. The researchers acknowledge that it was a “great learning experience with the possibility to find something that can drive space exploration into its next generation.”

Moreover, they managed to create the hypersensitive instrumentation that will likely be necessary to measure the very small amount of thrust that will be produced by these EmDrive prototypes if there is any thrust being produced at all.



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glenn
3 days ago
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"When they calculated the forces resulting from a combination of Earth’s magnetic field, the length of their cables and the electric current flowing through them, they found that the result was equal to a few micro-Newtons, which is comparable to the ‘thrust’ they had observed in the vacuum chamber."

If only they'd used some Monster cables...
Waterloo, Canada
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Reflections of Venus and Moon

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Reflections of Venus and Moon

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jepler
5 days ago
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this was pretty much the scene last night. except, without the ocean. and with cloudy haze. and with the glare of city lights. and some trees. and the photo I tried to take was awful on my cellphone. still, it was beautiful.
Earth, Sol system, Western spiral arm
glenn
5 days ago
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Waterloo, Canada
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Bitcoin’s Horrible Impact on the World

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My wish for 2018 is for the entire cryptocurrency boom to collapse in a titanic heap, leaving only charred ruins and a lot of LOLs in its wake. There are many reasons for this and anyone who loses their money investing in what is obviously a scam doesn’t get much sympathy from me. But among the reasons is its horrific energy impact.

Bitcoin’s energy footprint has more than doubled since Grist first wrote about it six months ago.

It’s expected to double again by the end of the year, according to a new peer-reviewed study out Wednesday. And if that happens, bitcoin would be gobbling up 0.5 percent of the world’s electricity, about as much as the Netherlands.

That’s a troubling trajectory, especially for a world that should be working overtime to root out energy waste and fight climate change. By late next year, bitcoin could be consuming more electricity than all the world’s solar panels currently produce — about 1.8 percent of global electricity, according to a simple extrapolation of the study’s predictions. That would effectively erase decades of progress on renewable energy.

Although the author of the study, Alex de Vries, an economist and data consultant based in the Netherlands, has shared these calculations publicly before, this is the first time that an analysis of bitcoin’s energy appetite has appeared in a peer-reviewed journal.

Bitcoin continues to soar in popularity — mostly as a speculative investment. And like any supercharged speculative investment, it swings wildly. Within the past 18 months, the price of bitcoin has soared ten-fold, crashed by 75 percent, only to double again, all while hedge funds and wealthy libertarians debate the future of the virtual currency.

Beyond its tentative success as a get-rich-quick scheme, bitcoin has an increasingly real-world cost. The process of “mining” for coins requires a globally distributed computer network racing to solve math problems — and also helps keep any individual transaction confidential and tamper-proof. That, in turn, requires an ever-escalating arms race of computing power — and electricity use — which, at the moment, has no end in sight. A single bitcoin transaction is so energy intensive that it could power the average U.S. household for a month.

Bitcoin may in fact be the single most appropriate way for the world to collapse–the combination of grotesque energy use in an era of climate change, speculative New Gilded Age capitalism, and libertarian asshole fantasies sums up so much of our world.

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glenn
5 days ago
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“Bitcoin may in fact be the single most appropriate way for the world to collapse – the combination of grotesque energy use in an era of climate change, speculative New Gilded Age capitalism, and libertarian asshole fantasies sums up so much of our world.”
Waterloo, Canada
acdha
5 days ago
The quip about Bitcoin being the epitome of the libertarian fantasy about getting rich without contributing anything to society is sadly spot on
fxer
6 days ago
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Bend, Oregon
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A functional pinball machine made entirely from Lego bricks

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Enlarge / Bre Burns showing off her pinball machine. (credit: The Brothers Brick)

If you're a nostalgia-minded geek, you might have a soft spot for the classic Space Lego sets, with their iconic orbiting rocket ship logo. You might also be fond of the physical action of pinball, full of tactile sensations so often missing from modern gaming. You probably never expected the two to meet in one of the more amazingly geeky pairings in recent memory, a pinball machine called Benny's Spaceship Adventure made entirely of Lego bricks.

Lego enthusiast Bre Burns used over 15,000 Lego bricks to build a fully functional pinball machine, and it's amazing. Every part (minus the plywood base used to help safely transport it) is made from Lego pieces, from official Lego rubber bands in the bumpers to Mindstorms steel castor balls—no glue, screws, or custom parts. The scoring, sounds, and electronics are controlled by three Lego Mindstorm NXT programmable bricks connected over Bluetooth. The Mindstorm systems include servo motors, touch sensors, color sensors, light sensors, and ultrasonic sensors, giving Benny's Spaceship Adventure a wide variety of ways to track and interact with the ball.

The dedication to staying with official parts continues to every detail. The LEDs are sourced from Lego, and so are the power sources, which can either be a Lego Power Functions battery box or a 9-volt Lego Trains speed regulator plugged into a wall socket. The game logic was all programmed using the native NXT-G environment. Perhaps the most authentic detail, though, comes from the side art, depicting a classic Space Lego helmet, with the bottom featuring the crack that every Space Lego owner knows is inevitable.

For more details on Benny's Spaceship Adventure's programming, the challenges Bre faced during the build, and her thoughts on using Lego for a pinball machine, read the write-up at The Brother's Brick. You can also see the machine in action and hear Bre describe her process in her own words in the following video.

Benny's Spaceship Adventure

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glenn
14 days ago
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Wow, this is incredible! Amazing detail and game play looks like a lot of fun.
Waterloo, Canada
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New UPS Trucks

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Adorable.

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glenn
15 days ago
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they're like huggable brown marshmallows
Waterloo, Canada
angelchrys
15 days ago
It's not often you think a truck is adorable, but this is pretty cute
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