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Negative mass observed by physicists. (Alcubierre Drive, anyone?)


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http://www.bbc.com/news/science-environment-39642992

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Prof Peter Engels, from Washington State University (WSU), and colleagues cooled rubidium atoms to just above the temperature of absolute zero (close to -273C), creating what's known as a Bose-Einstein condensate.

In this state, particles move extremely slowly, and following behaviour predicted by quantum mechanics, acting like waves.

They also synchronise and move together in what's known as a superfluid, which flows without losing energy.

To create the conditions for negative mass, the researchers used lasers to trap the rubidium atoms and to kick them back and forth, changing the way they spin.

When the atoms were released from the laser trap, they expanded, with some displaying negative mass.

"With negative mass, if you push something, it accelerates toward you," said co-author Michael Forbes, assistant professor of physics at WSU.

HOLY FUCKING SHIT.

P.S: I hope this means research into the Alcubierre Drive is viable.

Wikipedia:

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The Alcubierre drive or Alcubierre warp drive (or Alcubierre metric, referring to metric tensor) is a speculative idea based on a solution of Einstein's field equations in general relativity as proposed by Mexican theoretical physicist Miguel Alcubierre, by which a spacecraft could achieve apparent faster-than-light travel if a configurable energy-density field lower than that of vacuum (that is, negative mass) could be created.

 

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1 hour ago, Funyarinpa said:

P.S: I hope this means research into the Alcubierre Drive is viable.

Paging @Down because he smurt

But I feel like these are different kinds of "negative mass", focusing on negating different properties of regular mass. The one the researchers discovered seems like an exotic property of matter at specific circumstances, while the kind of negative mass you need for the Alcubierre Drive (if memory serves) is the kind that you can only get by warping spacetime in a specific way to create negative density.

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7 minutes ago, Flutterz said:

But I feel like these are different kinds of "negative mass", focusing on negating different properties of regular mass. The one the researchers discovered seems like an exotic property of matter at specific circumstances, while the kind of negative mass you need for the Alcubierre Drive (if memory serves) is the kind that you can only get by warping spacetime in a specific way to create negative density.

Pretty much this. I'm sure they mean an effective mass of the atoms, not their actual mass. For example, in some complex systems of interacting particles it's possible to describe them like a simple gas of quasiparticles with a different mass, called an effective mass. For example, in most semiconductors electrons behave like their mass is only about a 1/100 of the actual mass of an electron, and in graphene this value is exactly zero. The real value of the mass in that case, of course, doesn't change.

I mean, this result is actually pretty interesting, but it does not seem to be groundbreaking.

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24 minutes ago, Flutterz said:

Paging @Down because he smurt

Not my research topic so I'm not an expert, but you're right. The negative mass we're talking about here is an "effective negative mass" which is a result of the numerous strange behaviours that exotic states of matter like Bose-Einstein condensates display. Transposing classical concepts like mass to these purely quantum states of matter where even the notion of a substantial, individual particle breaks down would be misleading, it's quite different from what's involved in the speculative "negative mass" in general relativity.

But both are still cool. That's why we read sci-fi.

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8 minutes ago, Down said:

Not my research topic so I'm not an expert, but you're right. The negative mass we're talking about here is an "effective negative mass" which is a result of the numerous strange behaviours that exotic states of matter like Bose-Einstein condensates display. Transposing classical concepts like mass to these purely quantum states of matter where even the notion of a substantial, individual particle breaks down would be misleading, it's quite different from what's involved in the speculative "negative mass" in general relativity.

But both are still cool. That's why we read sci-fi.

Thanks! 

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