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Physicists Observe 'Negative Mass' (bbc.com)

Posted by msmash on from the breakthrough dept.

Physicists have created a fluid with "negative mass," which accelerates towards you when pushed. From a report on BBC: In the everyday world, when an object is pushed, it accelerates in the same direction as the force applied to it; this relationship is described by Isaac Newton's Second Law of Motion. But in theory, matter can have negative mass in the same sense that an electric charge can be positive or negative. 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.

117 comments

  1. Last Post by Big+Hairy+Ian · · Score: 4, Funny

    I'll get my coat

    --

    Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.

    1. Re:Last Post by Anonymous Coward · · Score: 0, Funny

      I predict negative score.

    2. Re:Last Post by Sir+Holo · · Score: 2

      In anti-matter universe, negative score predict you.

      Antimatter has mass. In fact, a given antiparticle has the same mass as its counterpart particle. Like, say, an antiproton and a proton.

    3. Re:Last Post by Pseudonym · · Score: 1

      Pics or it won't happen!

      --
      sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
  2. Negative Mass by Anonymous Coward · · Score: 0

    >But in theory, matter can have negative mass in the same sense that an electric charge can be positive or negative.
    Was it actually theoretically predicted? I don't mean just supposing it exists because you flipped a sign in an equation.

  3. Wow by Headw1nd · · Score: 2

    This sounds actually groundbreaking. Does anyone have more details? Were the authors trying to generate negative mass or was this an unexpected side effect? Obviously this is going to require some replication, but I'm excited.

    1. Re:Wow by Neuronwelder · · Score: 1

      Maybe this bit of information will be useful information towards creating anti-gravity propulsion?? Who knows.. There's a lot of stuff out there we don't know.

    2. Re:Wow by Baloroth · · Score: 5, Interesting

      This sounds actually groundbreaking. Does anyone have more details? Were the authors trying to generate negative mass or was this an unexpected side effect? Obviously this is going to require some replication, but I'm excited.

      That's because the headline is some of the worst sensationalistic tabloid journalism level garbage I've ever read. They did not observe "negative mass". They created a system wherein, under specific circumstances, part of the system behaved as if it mathematically had negative mass. Note that the entire system and every part of it individually still has positive mass: however, because of the way the system interacts with itself, when you do very specific things to it, parts of it can act (when taking very specific behavior) as if they had negative mass.

      The headline and summary are the equivalent of saying "man travels through space safely without spacesuit on!", without mentioning he's inside a spaceship.

      --
      "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
    3. Re:Wow by TeknoHog · · Score: 5, Interesting

      Yup, this sounds just like the reports of negative temperature. There, the distribution of particles was governed by a term like B*c*T, where B = external magnetic field strength and T = temperature. The field was suddenly reversed, but the particles didn't change their configuration immediately. The system looked like B*c*T for a while, but the field was now -B. So if you wrote the term as (-B)*c*(-T), it looked like the long-term equilibrium state at field -B and temperature -T. Of course, the system wasn't at equilibrium, so the math didn't really apply.

      --
      Escher was the first MC and Giger invented the HR department.
    4. Re:Wow by Tranzistors · · Score: 1

      They did not observe "negative mass". They created a system wherein, under specific circumstances, part of the system behaved as if it mathematically had negative mass.

      Man, you are gonna be angry when you find out about negative temperature.

    5. Re:Wow by Anubis+IV · · Score: 1

      That's because the headline is some of the worst sensationalistic tabloid journalism level garbage I've ever read. They did not observe "negative mass". They created a system wherein, under specific circumstances, part of the system behaved as if it mathematically had negative mass.

      Thanks for the clarification. While they may not have created actual negative mass, it's good to know that they've created something that the public will confuse for the real thing, since if there's one question I love hearing over and over again, it's "When will we have Jetsons-style flying cars and hoverboards?".

    6. Re:Wow by Anonymous Coward · · Score: 0

      The headline and summary are the equivalent of saying "man travels through space safely without spacesuit on!", without mentioning he's inside a spaceship, on a sound stage, on Earth.

    7. Re:Wow by Baloroth · · Score: 4, Informative

      Negative temperatures are actually a pretty well-defined and real thing, but that's just because of the way we define "temperature" in thermodynamics, which is not always exactly the same as what we think of as temperature in everyday life. The short explanation is that temperature (T) is the rate of change of energy (E) with respect to entropy (S) (in math: T=dE/dS). If I have a system that is bounded from above in energy (i.e. a maximum energy the system can reach), I can get negative temperatures. Simple example: let's say I have a system of particles, each of which can be in two states, a state with more energy, and a state with less energy. The entropy is the number of different states the *entire* system can be in, so if the system is in a minimum energy state (i.e. every particle is in the lower energy state) I have a minimum entropy system (every particle in the same state means I only have 1 possible state for the entire system). Likewise, in a *maximum* energy state, all the particles are also in the same state (the higher energy state), so I also have minimum entropy. Maximum entropy occurs when the energy is right in the middle between these: half the particles are in the higher energy state, half are in the lower energy state, so the entire system has the most possible configurations. So, if the system is in that state, and I add a bit of energy to it, I decrease the entropy (as there are fewer particles in the lower energy state and therefore fewer possible configurations). That means dE/dS is negative (since S goes down, so dS is negative, while dE is positive), so you get negative temperature.

      In every day life, systems typically aren't bound from above, and also any particles in higher energy states like that will fall into lower energy states and release energy (this is exactly how a laser works, incidentally), so you only get negative temperature in carefully constructed systems.

      The negative mass term in this case, however, is a negative effective mass (not a real mass) term that occurs in a group velocity (which is not the real velocity of particles in the system) dispersion relationship. Not to say the results aren't interesting: they are, they're just... well, not really negative mass at all.

      --
      "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
    8. Re: Wow by Anonymous Coward · · Score: 0

      Temperature is defined by the statistical properties of large systems and negative temperature means the system will try to lose energy to any other system of lower negative or positive temperature.

    9. Re:Wow by Areyoukiddingme · · Score: 2

      The headline and summary are the equivalent of saying "man travels through space safely without spacesuit on!", without mentioning he's inside a spaceship.

      Man travels through space safely without spacesuit on! Fetched another beer from the kitchen....

    10. Re:Wow by esperto · · Score: 1

      For post like this is that I still come to /.
      Thanks!

  4. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    Nope. It implies the possibility of FTL travel.

  5. Nice trick by ByteSlicer · · Score: 5, Informative

    But if it truly had a negative inertial mass, it should spontaneously move upwards, because there already is a force pulling it downwards (gravity).

    As it is, it just behaves like a negative inertial mass under certain strict conditions, which is somewhat interesting, but not a ground breaking discovery. That said, go science!

    1. Re:Nice trick by Anonymous Coward · · Score: 1

      Not quite. When one mass is negative, the attractive force result from gravity between two objects is negative, but a negative force applied to a negative mass results in a positive displacement. So it will still fall toward the earth, but in the process it provides a minuscule push on the earth away from itself.

      It is mathematically valid for two equal and opposite masses in an otherwise featureless infinite vacuum to accelerate with no additional energy added to the system. The positive mass would be falling away from the negative mass, which would be falling toward the positive mass.

    2. Re: Nice trick by Anonymous Coward · · Score: 1

      In what sense? Gravity certainly applies a force to objects. In fact it always does, we don't have the ability to prevent it. So whether gravity is waves, or particles, or both, or just a change in the shape of space-time, the end result is it applies a force.

    3. Re:Nice trick by rkordmaa · · Score: 1

      If gravity is not considered a force I don't know what "force" means anymore, unless that is you meant that in star wars sense.

    4. Re: Nice trick by Khashishi · · Score: 2

      In general relativity, gravity is a curvature of spacetime. It does not produce any proper acceleration of a test object, so it can be regarded as a fictitious force, like centrifugal force. In other words, we can choose coordinates in which there is no acceleration in the test object.

      Of course, this is just one way to look at it. In other physical contexts, we can view gravity as a force. It's not wrong to do so, since the meaning is context sensitive.

    5. Re:Nice trick by jellomizer · · Score: 2

      Still we are taught that force of gravity is in relationship of the mass. I would like to find out if Anti-Mass produces anti-gravity. or it may not, but checking the gravitation observed force may bring light into how gravity works.

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
    6. Re:Nice trick by ByteSlicer · · Score: 2

      While you are technically correct (which is the best kind of correct), there still would be a measurable upward component, meaning the condensate would accelerate less when released from the laser trap.
      This was not what they found in the experiment, instead they found differences in expansion rates of different regions of the condensate, perpendicular to the direction of gravitational acceleration, an effect caused by a different external force.

    7. Re:Nice trick by Anonymous Coward · · Score: 0

      I'm not defending the article hype, just criticizing your statement about the dominant direction.

    8. Re:Nice trick by Anonymous Coward · · Score: 0

      Was going to say the same thing. Gravity is a curvature of spacetime. However I am curious about what sort of curvature would result from an earth-sized lump of matter with negative inertial mass.

    9. Re:Nice trick by Anonymous Coward · · Score: 1

      You feel a "force" because you are living in an accelerated frame of reference. That acceleration is being provided by the ground, which is exerting just enough upwards force to keep you accelerating at about 10m/s^2 in that direction. If you want a non-accelerated frame of reference try a satellite or free-fall and note the complete absense of any "force".

      Another viewpoint: the really weird thing about gravity as a force is that the "force" applied is proportional to the the inertial mass of the object it is applied to - so for example the earth exerts twice as much "force" on a 200kg person than a 100kg person. Which is really very strange when you think about it, and not at all like other forces where inertial mass is completely unrelated to exerted force. Another strange and apparently unrelated thing is Euclid's fifth axiom: the angles inside a triangle add to 180 degrees, or parallel lines never meet. It's the only one that requires non-locality, and it is observably false on a cosmological scale (assuming light travels in a straight line). Roughly speaking GR works like this: let's drop that weird fifth axiom and let space be curved... woah that extra freedom looks a lot like an acceleration if you get your frame of reference right... hang on if we relate curvature to mass (well technically the stress-energy tensor) then we can have gravity without needing that bizarre force-is-proportional-to-inertial-mass thing... and hey, it matches our experimental results better.

    10. Re: Nice trick by Anonymous Coward · · Score: 0

      Rather than saying Earth is pulling twice as hard on the 200kg mass, why can't we say the 200kg mass is pulling back on the Earth twice as hard?

    11. Re:Nice trick by peawormsworth · · Score: 1

      IMO.. If you think of gravity as a warp in space-time and strong positive gravity is represented the shape of space-time around a black hole, then a white hole would have warped space-time around it that represents "negative gravity". I think.

      Maybe the big bang is a white hole location in space-time. So you can imagine that negative gravity is everywhere you look into the far distance just beyond what you can see.

  6. It's not actually negative mass by Baron_Yam · · Score: 5, Informative

    It's analogous to negative mass (if such a thing could actually exist) in that some of the observed behaviours map to those calculated for negative masses.

    This is an important difference, much like when we saw pop science reporting on 'table top black holes'. They weren't actually black holes.

    1. Re:It's not actually negative mass by Anonymous Coward · · Score: 0

      Thank you for RTFA.

      Now someone please:
      1. Mod post up.
      2. Mod story down.
      3. Move on to something else.

    2. Re:It's not actually negative mass by Anonymous Coward · · Score: 0

      It's analogous to negative mass (if such a thing could actually exist) in that some of the observed behaviours map to those calculated for negative masses.

      Yes, analogous in the same way a helium balloon in my car move the opposite way (back to front) when I accelerate. These are some special atoms in a sea of atoms. Most of the rest (like the air in my car) are moving the normal way, giving the appearance of negative mass. I'm sure there is something cooler (ha) than that about this experiment, but that is as far as the article seems to go.

  7. Bottle it... by QuietLagoon · · Score: 1

    ... and sell it as a weight-loss drink.

    1. Re:Bottle it... by Anonymous Coward · · Score: 0

      There's no question that drinking a superfluid just above absolute zero would cause weight loss.

  8. Time to build a warp drive by Anonymous Coward · · Score: 0

    I seem to recall the Alcubierre drive requiring something like this. Perhaps it's time to start designing a warp drive now?

    https://en.wikipedia.org/wiki/Alcubierre_drive#Mass.E2.80.93energy_requirement

  9. Seems like an error by Anonymous Coward · · Score: 0

    Its too early to have this as a groundbreaking physics. Tomorrow they would come back saying "No we made an error in computation". Happens all the time. Remember the fiasco of the dark matter. Its still going see-saw.

  10. Re:doesn't "accelerate" by Anonymous Coward · · Score: 0

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

    Hmmm, as someone who doesn't understand this kinda stuff, (and assuming he wasn't misquoted), I think I'll believe the professor of physics over the random /. poster.

  11. Pop science reporting... by Anonymous Coward · · Score: 0

    I think the only decent science reporting for the lay person in in Scientific American, Economist and Discover.

    Every where else it's so oversimplified that the science is misunderstood and even wrong.

    TV science reporting - unless they have someone like Bill Nye - is just pathetic.

    1. Re:Pop science reporting... by Anonymous Coward · · Score: 0

      Ever watch the Nova program on PBS?
      They do some good science reporting.

    2. Re:Pop science reporting... by pr0fessor · · Score: 1

      TFA doesn't have enough detail to really say what was observed. From the minimal description, I can think of a few reason you might see an effect like this. If they are releasing a liquid cooled to near absolute zero from a laser trap I would imagine they are not just tossing it on the floor for safety sake so pressure in what ever they are using to contain it could cause a similar effect when it rapidly expands.

  12. Antimatter? by pak9rabid · · Score: 1

    So, would this be considered antimatter?

    1. Re:Antimatter? by Anonymous Coward · · Score: 2, Insightful

      Anti-matter has positive mass and inertia. The Higgs particle is its own anti-particle.

  13. I remember reading about this in theory... by lazlo · · Score: 1

    A long time ago, I recall reading about the theory of negative mass, and if I recall correctly, it should allow for the creation of pseudo-reactionless drives. Technically, it isn't reactionless because it's obeying all the laws of reaction drives, it's just that f=ma gets weird when m0.

    So if you have a ship that contains equal parts mass and negative mass, its "total mass" will be 0, and any force applied to it will instantly accelerate it to lightspeed.

    It's always been one of those things I assumed would be permanently theoretical. If they actually made some, that's absolutely fascinating.

    --
    Pound! Bang! Bin! Bash! is this a shell script or a Batman comic?
    1. Re:I remember reading about this in theory... by Tighe_L · · Score: 1

      I think that it would rip itself apart as soon a force where applied.

    2. Re:I remember reading about this in theory... by Anonymous Coward · · Score: 0

      Neither! And for one of the less intuitive yet mathematically valid reasons reasons.

      In casual macroscopic scale, the force of gravity between two objects is the product of their masses divided by the distance between them, and then converted into a familiar unit with one of the gravitational conversion constants.

      Force = mass * acceleration, so acceleration = force/mass

      When calculating the gravitational attraction between a positive mass and a negative mass, the resultant force is negative.
      When calculating the acceleration from a negative force applied to a positive mass, the acceleration is negative.
      When calculating the acceleration from a negative force applied to a negative mass, the acceleration is positive.

      Short form, two equal and truly opposite masses will, with no energy input, accelerate at a constant rate equal to how fast they would start falling together if both masses were positive (in the direction of a vector starting at the initial position of the negative mass and going through the initial position of the positive mass).
      Drawback, you now have a familiar mass accelerating to near light speed that will definitely react to anything it hits exactly the same way a can of ravioli with the same difference in relative velocity would. The negative mass chasing it becomes fairly irrelevant after that.

    3. Re:I remember reading about this in theory... by silentcoder · · Score: 1

      There's a better version. Take a lump of something (A) with m = -1 and chuck it at a lump of something (B) with m = 1. B is attracting A due to gravity, but A is repelling B due to gravity - and you have perpetual motion because B keeps being pushed away from A as fast as A falls toward it.

      But personally my bet is that they would simple bounce around a bit until they reach a point where the repellent effect of B and the attractive effect of A cancel out and then stop in a dead balanced state there - not all that different from magnetic levitation except that instead of gravity being cancelled by magnetism you got two cancelling gravitational forces.

      --
      Unicode killed the ASCII-art *
    4. Re:I remember reading about this in theory... by freeze128 · · Score: 1

      That's what I thought too. Maybe this could be mitigated if your equal parts mass and anti-mass were evenly distributed throughout every material in the ship.

  14. Needed for Warp Drive by exabrial · · Score: 1

    One of the fundamental "flaws" in Warp drives is need for exotic states of matter like negative mass. One step closer to FTL travel! Only 2000 years more of technology development needed!

    1. Re:Needed for Warp Drive by Baron_Yam · · Score: 1

      And this is why I hate this article... THEY HAVE CREATED NEGATIVE MASS. They've created something that behaves sort of like you'd expect negative mass to behave if it were possible.

      Actual negative mass is not possible, which is just one of many reasons a warp drive is not possible (which I personally find disappointing, but it's still true).

    2. Re:Needed for Warp Drive by Baron_Yam · · Score: 1

      Oh, FFS. Shouting in all caps and all and I forget the critical 'NOT'.

      They have NOT created negative mass.

    3. Re:Needed for Warp Drive by mark-t · · Score: 1

      No. Only a little less than half of that

      --
      File under 'M' for 'Manic ranting'
    4. Re:Needed for Warp Drive by Anonymous Coward · · Score: 0

      THAT WILL TEACH YOU

  15. Re:Negative mass? AKA progressive "brains"? by blackomegax · · Score: 1

    Seize the means of production before the means of production seizes you.

  16. negative *effective* mass by Anonymous Coward · · Score: 1

    Not really negative mass. We like often to model some behavior in the "effective" counter behavior in case of negative. E.g. model electron holes.

  17. Fake news by Anonymous Coward · · Score: 0

    The correct title should be 'physicists observe a range of dynamical phenomena in fluid with negative _effective_ mass'.
    Interesting, but nothing groundbreaking. Move along.

  18. Re:doesn't "accelerate" by Anonymous Coward · · Score: 1

    Why do you think accelerate implies perpetual motion. Acceleration is simply a change in speed or direction.

  19. Where can I buy one? by Anonymous Coward · · Score: 0

    Does amazon sell this yet?

  20. Re: Negative mass? Nationalism by Anonymous Coward · · Score: 0

    You're brilliant. Just wait until your home is taken away because "nationalism.". Oh wait...my bad. Your mom's home and your basement bedroom.

  21. source source... by Anonymous Coward · · Score: 0

    https://www.sciencedaily.com/releases/2017/04/170417095534.htm

  22. Re:doesn't "accelerate" by Anonymous Coward · · Score: 0

    Acceleration is JUST a change in speed not 'or direction'

  23. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    You can capitalize all the words you want, but OC is still correct. Acceleration is still as he stated, a change in speed OR direction.

  24. Mass as potential gravity by Anonymous Coward · · Score: 0

    Take a two chunks of mass, A and B. If A is mass and B is mass there is a force between them, gravity. If A is mass but B is changed to photons, there is NO gravity (little) between them. Yet B is what it was, so where did the mass go. What actually happens when matter turns to energy and energy to matter?

    Let me have another go at convincing you what's going is simple.

    I described a simulation yesterday, using nothing but two simple particles one +ve and -ve they organize themselves into complex twisting spinning closed hoops given time. There's bits to this I didn't cover. The dipoles are *massless*, yet can form particles with mass.

    How?

    Dipoles exhibit a force on each other, its an organizational dipole force. You see it in water, you see this in dust, it's well understood. Diploes always arrange themselves so the attraction ends line up and the repelling ends are pushed apart. This is true of spinning dipoles too, they exert a force on remote points that is wave, that wave 'kicks' other distant dipoles into sync, just as those dipoles kick the original into sync. Let's call it dipole force for short.

    Dipole organisation force is always an attraction.
    Although its a wave, the force is not net zero, because the force is applied to other matter which itself is a wave, and the net force depends on both wavelengths.

    So think of small bead magnets in a bag, shake them, they arrange themselves to stick together. Now think of large bar magnets in a bag, they stick together with much stronger force because the separation from the poles is larger. Dipole force is stronger if you put more distance between the ends of the dipole, and obviously it's stronger for stronger charges and stronger between hoops of the same wavelength.

    Take a cloud of disorganized random spinning dipoles. These are ZERO mass in the conventional sense. They spin in all-different-ways, and a remote chunk of matter experiences net zero dipole force.

    After these dipoles have arranged themselves into a twisting hoop, a simple one wavelength hoop for example, has half of the hoop +ve upwards and half -ve upwards. It is a stronger charge and clear separation. It exerts a net attractive force on other matter. It's the *same* dipoles, just in a different organization.

    It goes from energy to mass just by a change in organization of the dipoles. Same group of dipoles, different arrangement, one exhibits an attraction force, the other exhibits minimal attaction force.

    So if you treat matter as potential gravity, not as 'stuff' then the difference between energy and matter is whether it can exhibit a force or not.... i.e. its the same, just down to the structure.

    1. Re: Mass as potential gravity by Anonymous Coward · · Score: 0

      I read that whole post imagining your room slowly filling with helium while you were speaking on a talk show. As in that episode of Big Bang. Made it much more enjoyable!! LOL sorry.... :)

  25. Oh..... by Anonymous Coward · · Score: 0

    ...I thought they were talking about an unhappy religious ceremony of some sort.

  26. yea, right by frovingslosh · · Score: 2

    Take a group of atoms, remove heat, and suddenly they change from having positive mass to negative mass. Children, what have we been telling you about critical thinking and not buying into obvious bullshit?

    --
    I'm an American. I love this country and the freedoms that we used to have.
  27. Re:doesn't "accelerate" by Anonymous Coward · · Score: 1

    Acceleration is a change in velocity. Velocity is a vector, comprising speed and direction. Change either of those and you're accelerating.

  28. Re: Negative mass? AKA progressive "brains"? by Anonymous Coward · · Score: 0

    I don't think, technically, a government can do anything "illegal", at least within their own framework. They typically allow themselves sovereign immunity. Even in the US you can only sue the government if they permit it.

  29. Unfortunately ... by PPH · · Score: 2

    ... the negative mass fluid was lost when a scientist set the beaker on a table and it spilled out all over the ceiling.

    --
    Have gnu, will travel.
    1. Re:Unfortunately ... by budgenator · · Score: 2

      If I had points, you'd get +1Funny

      --
      Apocalypse Cancelled, Sorry, No Ticket Refunds
  30. wow..? by Reisrdok · · Score: 1

    Interesting. So in theory you could create thrust inside a sealed container? Sounds like troll physics to me.

    1. Re:wow..? by serviscope_minor · · Score: 2

      So in theory you could create thrust inside a sealed container? Sounds like troll physics to me.

      You wuldn't believe how many people here seem to think the EM drive works.

      --
      SJW n. One who posts facts.
  31. Welcome to alt journalism by Anonymous Coward · · Score: 0

    Back in the day, misleading / unfounded click-bait had to end the title with ?, to claim minimal legitimacy.
    The new standard appears to be '' quotation marks to cover any interpretation of alternate facts.

    *sigh*

  32. Not new? by goombah99 · · Score: 2

    This negative mass effect looks a lot like the usual negative mass effect to describe some collections of holes/electrons. One can explain some of the phenomena of these as acting like they have a negative mass or negative (negative) charge. But they are mathematical fictions since they only arise as apparent behaviours on a fictional individual represeting the effective forces created by the correlated motions of a large ensemble. One can do something similar with magnetic monopoles. There are not (supposedly) magnetic monopoles but if you stack dipoles end to end then one can get two very well separated poles that behave as though they were independent monopoles.

    Maybe I'm wrong, but Ive seen this negative mass explanation before so I'm guessing this is similar, not a new effect.

    --
    Some drink at the fountain of knowledge. Others just gargle.
    1. Re: Not new? by Anonymous Coward · · Score: 0

      If matter is energy then there's negative energy?,I'm not talking about negative charge that's truly impressive would then be a negative deformation of space time? if normal matter deforms it in a let's all it positive way this one would deform it in a negative way? that would be be anti gravity and not sure if it also can affect the time. That's a huge discovery if it is what they claim

    2. Re: Not new? by goombah99 · · Score: 1

      no it's a ficitonal mass.

      --
      Some drink at the fountain of knowledge. Others just gargle.
  33. Hmmm... by drew_92123 · · Score: 1

    I bet negative mass engines are just around the corner too... ;-)

    1. Re:Hmmm... by budgenator · · Score: 1

      Cool, if you had one tank of fuel with positive mass, and one with negative mass, you could decelerate by just switching fuel!

      --
      Apocalypse Cancelled, Sorry, No Ticket Refunds
  34. We know how Gravity behaves but not what is is. by Anonymous Coward · · Score: 1

    Isn't it actually a case where gravity behaves like a curvature of space and time? Seems like we can describe the effects of gravity and make analogies of those effects, but do we really have any idea how it actually causes those effects?

    1. Re:We know how Gravity behaves but not what is is. by Anonymous Coward · · Score: 1

      Different physicists will give you different answers on this one. Some will say what you say: that all this spacial curvature stuff is just a model of how the force works, but in reality, space is flat. Others will so no, flat spacetime requires additional axioms to construct (angles of triangles add to 180, or straight lines remain parallel forever), so curved spacetime is by definition more natural - and besides, these axioms make predictions about reality (angles in triangles add to 180, parallel lines don't cross), so they need to be subjected to the same experimental verification as any other physical theory, and applying Ockham's razor it is simpler to say "spacetime is curved with curvature satisfying Einstein's field equations" rather than "spacetime is flat - aka its curvature is set to zero - but we have this additional force that makes matter act as though it was travelling through a curved spacetime satisfying Einstein's field equations (not Newtonian gravity as that is observably wrong)". Still others will say that spacetime is an illusion in some way and "real" reality is all strings in 26 dimensions, loops, foams, branes, or other mathematical constructs.

      It all comes down to how you apply Ockham's razor, which you could argue comes down to an aesthetic judgement of simplicity.

      (FWIW I fall on the side of those who say that curved space plus Einstein's field equations is the most natural / simple picture)

    2. Re:We know how Gravity behaves but not what is is. by Anonymous Coward · · Score: 0

      Not to mention that you can't accelerate a photon, but gravity can affect it. The effect of Gravity is not acceleration unless you're willing to break much of physics.

  35. Re:doesn't "accelerate" by Anonymous Coward · · Score: 0

    Completely incorrect. A satellite travelling at a constant speed is continually accelerating toward the earth.

  36. Negative Conclusions by Anonymous Coward · · Score: 0

    The only thing I predict is a negative on the conclusions.

    I'm not convinced it's doing exactly what is described, or at least not for the reasons they described.

  37. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    So throwing it in reverse will lunge forward until we crash into a giant Amoeba.

  38. Observation vs. experience.. by 3seas · · Score: 1

    I gots lots of negative mass experience.... *&%@!##*11

  39. Re:doesn't "accelerate" by Anonymous Coward · · Score: 0

    No, it's not accelerating towards the earth, it is simply falling towards the Earth at the same rate the Earth curves away. The velocity remains the same.

  40. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    Like when I'm pooping. Don't go in there for about 2 hours.

  41. Re: doesn't "accelerate" by Anonymous Coward · · Score: 1

    I thought it implied that we'd created the immovable object.

    If pushing it causes it to want to move towards you, then it is going to want to occupy the same space as your hand. But since two objects cannot both exist in the same place at the same time, it should move no where. Thus, we have the immovable object.

  42. Negative mass by Anonymous Coward · · Score: 0

    My cat has been doing this for years. Many children behave this way too.

  43. Re:doesn't "accelerate" by Newander · · Score: 1

    Falling towards the Earth is a form of accelerating towards the Earth.

    --

    Jesus saves and takes half damage.

  44. Sounds more like a tractor beam to me... by slew · · Score: 1

    Like described in this /. story back in 2014...

  45. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    The velocity does not remain the same. The speed remains the same, which is the magnitude of the velocity. The velocity changes continually, rotating as the object moves along its orbit.

  46. warp drive by Anonymous Coward · · Score: 0

    so wasnt negative mass a requirement for making warp drive? if so is it usable for that purpose ?

  47. Re:Negative mass? AKA progressive "brains"? by Anonymous Coward · · Score: 0

    It's not illegal within the country, but it may be a violation of international law (ultimately enforced with guns) or a treaty violation (also punished with guns). Aside from that, it's pretty stupid because while multinationals can tolerate a tax increase, they generally won't tolerate 100% confiscation. Thus, it's unlikely that anybody will invest in your country until after regime change. They've crossed a threshold with this move--radical isolationism with very limited trade because none of their agreements are honored, or full revolution.

  48. Let me correct that headline by caffeinated_bunsen · · Score: 4, Insightful

    No They Didn't, You Bloody Idiots

    Reporters at the BBC discovered today that reporting on scientific experiments without basic background knowledge can result in wildly inaccurate headlines. The reporters' usual technique of absentmindedly skimming someone else's account of an event, copying a few juicy-sounding words, and filling in the rest with fluff turned out to completely misrepresent the actual science.

    When asked for comment, a BBC spokesman said, "Piss off, egghead. You clicked on it, didn't you? Mission fucking accomplished on our end."

    --

    Bugrit! Millenium hand and shrimp!
  49. Just another BEC experiment? by Trogre · · Score: 1

    Okay, so we know by now that this isn't actually negative mass.

    Would any physicists here care to chime in on whether this particular experiment is any different from the dozens of others that have resulted in Bose Einstein Condensates and, if so, what sets this one apart?

    --
    "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
  50. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    Wouldn't pulling towards you cause it to move the other way?

  51. About gravity being the curvature by evanh · · Score: 1

    I've always viewed gravity as being the mass interacting force that warps space-time, ie: the curvature is an effect of gravity rather than gravity itself.

  52. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    Acceleration is "just" a change in velocity, not speed.

  53. Re: Negative mass? Nationalism by Anonymous Coward · · Score: 0

    Sovereign immunity.

    You don't have to like it for it to be legal.

  54. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    The speed doesn't even stay the same if the orbit isn't perfectly circular, which it is not.

  55. Re:doesn't "accelerate" by OrangeTide · · Score: 1

    if it was not accelerating then it would move in a straight line. That it changes direction should be a clue.

    Angular velocity is not velocity, it's more like a metaphor.

    --
    “Common sense is not so common.” — Voltaire
  56. Re: doesn't "accelerate" by Anonymous Coward · · Score: 0

    It is moving in a straight line, which is why it neither flies off into space nor crashes into the ground, but stays parallel with the earth's surface

  57. Re:Negative mass? AKA progressive "brains"? by yndrd1984 · · Score: 1

    A stolen GM plant? Monsanto's going to be pissed ... wait, you meant cars?

  58. Re:doesn't "accelerate" by Anonymous Coward · · Score: 0

    Wrong. The satellite is moving in a strait line through space-time. Space-time is curved, but the satellite is in an inertial frame. If you placed an accelerometer on a a satellite, you would not measure any acceleration because there is none. This is why Relativity does not treat Gravity as a force, because it does not actually accelerate anything, it just warps space-time.

  59. A bit late to the party, eh? by michael_wojcik · · Score: 1

    Pfft. Negative Catholics have been observing Negative Mass for centuries.

    (Well, to be fair, most are non-observant and only show up for Negative Easter.)

  60. Slashdotters fall for this one weird trick by vandamme · · Score: 1

    Next: Phlogiston and magnetic monopole phenomena discovered!

  61. Sadly by maclark88 · · Score: 1

    Sadly, I had a girlfriend like that.

  62. Re:doesn't "accelerate" by michelcolman · · Score: 1

    You haven't met many assistant professors, have you?

  63. Re:doesn't "accelerate" by mcswell · · Score: 1

    My initial reaction was that AC couldn't be right; a satellite and a ray of light starting out in the same direction would diverge in space, and they couldn't both be straight lines. But that was my misunderstanding. They would not both follow straight lines in *space*, but they would in *space-time*. There's a useful explanation here: http://curious.astro.cornell.e...

  64. Re:doesn't "accelerate" by Anonymous Coward · · Score: 0

    What about this old one : F = m a