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3.05.2015
Schneller als das Licht
Warp-Antrieb im Labor: Laser-Test überrascht Nasa-Forscher
Star Wars, Raumschiff Enterprise, Star Trek, in allen Science-Fiction-Streifen ist eine Reise per Warp-Schubkraft ganz normal – dabei ist die Idee eines Raumzeit verkrümmenden Antriebs umstritten. Ein Nasa-Test könnte das jetzt ändern.
Wissenschaftler der Nasa haben jetzt einen elektromagnetischen Antrieb in einem Vakuum getestet, der Partikel auf eine höhere Geschwindigkeit beschleunigen konnte, als die konstante Lichtgeschwindigkeit von etwa 1 Milliarde km/h, die bislang als absolut maximale Höchstgeschwindigkeit von Partikeln angesehen wurde. Sollte dies zutreffen, so wäre die Messung ein möglicher Hinweis darauf, dass der sogenannte EmDrive-Antrieb ein Warp-Feld beziehungsweise eine Warp-Blase erzeugt haben könnte. Der EmDrive wandelt elektrische Energie mittels Mikrowellen in Schubkraft um, wodurch kein Treibstoff mehr benötigt würde. So könnte nicht nur Reisen im All sondern auch auf der Erde revolutioniert werden.
Quelle: Focus
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Update: 7.05.2015
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That NASA Warp Drive? Yeah, It’s Still Poppycock
A WEEK AGO, in a far-off corner of the Internet, a little website called NASAspaceflight.com published a story about a futuristic propulsion drive that produces thrust without propellant. Amazing! said the rest of the Internet. A drive that can run without heavy propellant opens up travel to the farthest reaches of space. Not only that, but the NASA-based group testing the drive had detected a slight spatial distortion around it—a warp, in other words. As in “warp speed” and “warp drive.” Not only could humans get to deep space unencumbered by fuel, but they could even travel faster than the speed of light!
Does that sound too good to be true? Excellent. This isn’t the first time that this theoretical drive—tested by a small lab called Eagleworks, based at NASA’s Johnson Space Center—has surfaced. Every time it comes up, it gets the space nerds frothing about the possibility of interstellar travel. And every time, physicists have to settle everyone down.
This time is like those times.
Last year, the Eagleworks lab—headed up by Harold “Sonny” White—said at a conference on propulsion technologies that they had measured thrust from an electromagnetic propulsion drive. The basic idea behind an EM drive, which is based on a design from a British engineer named Roger Shawyer, is that it can produce thrust by bouncing microwaves around in a cone-shaped metal cavity.
That would be awesome, of course, except it violates one of the fundamental tenets of physics: conservation of momentum. Saying that a drive can produce thrust without propellant going out the backside is kind of like saying that you can drive your car just by sitting in the driver’s seat and pushing on the dashboard.
Now, the last time this idea popped up it made a bunch of noise, which eventually settled down because of some pretty (ahem) obvious flaws in Eagleworks’ experiments. The physicists hadn’t run the tests in a vacuum—essential for measuring a subtle thrust signal. And while they had tested the drive under multiple conditions, one of them was intentionally set up wrong. That setup produced the same thrust signatures as the other conditions, suggesting that the signals the physicists were seeing were all artifacts.
This time around, Eagleworks researchers said they had addressed one of those problems. “We have now confirmed that there is a thrust signature in a hard vacuum,” wrote Eagleworks member Paul March in a forum. It was that post—all the way back in February—that led to most of last week’s hullabaloo.
Let’s be clear, though: Just because this time the group conducted its experiments in a hard vacuum doesn’t mean that an interstellar warp drive is soon to come. Marc Millis, who headed up the now-defunct Breakthrough Propulsion Physics lab at NASA’s Glenn Research Center—which, like Eagleworks, was dedicated to finding science-fiction-sounding ways to move a spaceship—says there are plenty of other interactions between the drive and the test chamber that could account for the results. “Even if it was done in a hard vacuum,” Millis says, “you have to take into account the distance between the drive and the chamber wall, whether those walls were conductive, and the geometry of the system.”
On top of that, there’s no way to be sure that the tests were run in a hard vacuum—because the only source of information is a post on an Internet forum. Not a peer-reviewed published result, not even a one-off conference proceeding. Let’s not do science like that, OK?
You’ve just read nine paragraphs of credulity, which is frankly more than the work deserves. The reason the Eagleworks lab presents results in unrefereed conference proceedings and Internet posts, according to Eric Davis, a physicist at the Institute for Advanced Studies at Austin, is that no peer-reviewed journals will publish their papers. Even arXiv, the open-access pre-print server physicists default to, has reportedly turned away Eagleworks results.
Why the cold shoulder? Either flawed results or flawed theory. Eagleworks’ results so far are very close to the threshold of detection—which is to say, barely perceptible by their machinery. That makes it more likely that their findings are a result of instrument error, and their thrust measurements don’t scale up with microwave input as you might expect. Plus, the physics and math behind each of their claims is either flawed or just…nonexistent.
For example: How might the EM Drive get around that pesky conservation-of-momentum problem? Eagle works says the microwave field generated in the drive’s cavity could be pushing against quantum vacuum virtual plasma. “The problem is there’s no such thing,” says Davis. Millis, for his part, doesn’t even pay attention to White’s work out of Eagleworks: “If it’s not impartial, I don’t read it.”
So who are these guys? Despite the fact that the group works out of Johnson, under the auspices of NASA, Eagleworks still only runs on $50,000 a year in funding. “That’s not enough to conduct a high-quality experimental research program,” says Davis. “They’d need $1.5 million, $2 million for five, six, seven years.”
Research into breakthrough propulsion physics—even when it had its own lab at Glenn, under Millis—has never been particularly well-funded. So “the way that this really happens is people dabble in addition to their day job,” says Millis. According to him, Eagleworks started with White working on concepts in his free time, not officially supported or sanctioned by NASA, and then eventually got a little money to run his lab out of Johnson. But the NASA banner doesn’t legitimize the work—if anything, NASA seems to want to keep the project under the radar. The press office at Johnson Space Center denied requests for interviews with March and White.
Davis and Millis both admit that they’re on the fringe. They’re scientists who strongly believe in the potential for warp drives and interstellar travel. So maybe it’s a little funny to hear them essentially say that other would-be warpsmiths are crackpots. But White and his colleagues exist on the fringe of the fringe. “We’re all open-minded people,” says Davis. “We’re all in the business of finding the breakthrough. But we have a standard of rigor, based on incremental research and development—not big leaps in logic.”
When someone builds a warp drive that violates conservation of momentum, you’ll read about it here, accompanied by a big old mea culpa. But until then, don’t believe the hyperspace.
Quelle: WIRED
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