3 ms·

The headline is deeply misleading. This article is not about classical negative mass or exotic matter – which would be major breakthroughs. https://en.wikiped

The headline is deeply misleading. This article is not about classical negative mass or exotic matter – which would be major breakthroughs. https://en.wikipedia.org/wiki/Negative_mass https://en.wikipedia.org/wiki/Negative_mass It is about "engineering" of the dispersion relation – wave-related phenomena that can have counter-intuitive effects at small scales where multiple waves interfere: https://en.wikipedia.org/wiki/Dispersion_relation https://en.wikipedia.org/wiki/Dispersion_relation In this case, the "counter-intuitive" effect is that the particles appear to move the wrong way when subjected to forces, resulting in an "effective mass" with a negative sign: https://en.wikipedia.org/wiki/Effective_mass_(solid-state_physics) https://en.wikipedia.org/wiki/Effective_mass_(solid-state_ph... The particles still have exactly the same (positive) mass, they're just moving the wrong way due to wave interference. If you want to be super misleading... why not call it a "tractor beam"? They're applying a push force but the particle is moving towards the push. As others have noted, the abstract for the paper correctly characterizes the phenomena as "negative effective mass". That word "effective" makes all the difference.

SubiculumCode 10y ago
Thanks. Too bad it isn't real negative mass. How about imaginary number mass?
- deleted 10y ago
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- nograpes 10y ago
  I thought you were joking, but I came across this: https://en.wikipedia.org/wiki/Mass#Tachyonic_particles_and_imaginary_.28complex.29_mass https://en.wikipedia.org/wiki/Mass#Tachyonic_particles_and_i... and was surprised that a plausible notion of imaginary mass exists.
  - SubiculumCode 10y ago
    Well being a layman, I had no idea if I was joking or not. :) Actually the idea of negative mass made me wonder if this would open the possibility for FTL space travel...Ran into a comment on the internets somewhere that said "no, because the mass is squared in the relation with energy, but the existence of imaginary masses might" Thanks for the link.
  - godelski 10y ago
    Many times people will see an asymptote and say "Hey, what would happen if I crossed that? What would the math and physics look like?" Tachyons are actually a great example of this. Taking the relativistic mass equation and asking "What would happen if I allowed for speeds larger than the speed of light?" Science is more a process of elimination. What does the math say? Can we observe what the math says should happen? Repeat.
vosper 10y ago
Thanks. Every time I see a university press release on HN I jump to the comments first, because there's always someone like you who's helpfully debunked the PR spin (no pun intended) to explain what's actually happening.
dwaltrip 10y ago
It's quite unfortunate that an official university news release seems to purposefully mislead its audience. Or do they really just assume that no one cares about the difference? I find that hard to believe. I suppose incompetence is also a potential explanation.
- djsumdog 10y ago
  PhD comics really explains this pretty well: http://phdcomics.com/comics.php?f=1174 http://phdcomics.com/comics.php?f=1174 I thought they did a video on the science/news cycle as well, but I can't seem to find it.
  - forgotmysn 10y ago
    im sorry, but to me that comic doesn't explain it one bit. the university press in the comic doesn't (appear) to deliberately click-bait the headline, it seems to be a process in your example. Washington State University appears to to have bypassed that process and gone straight for the misleading, click-bait title. This is disappointing because who better than the University Press themselves to try to provide as much clarity as possible. It's not like they don't have access to good sources...
    - TeMPOraL 10y ago
      The incentives of university's PR department aren't to provide accurate reporting on what's happening in said university to other scientists; it's to generate "buzz" around the university so that ultimately it gets more money. In this way, it's no better than regular news sources, and thus the quality is more-less the same.
      - dwaltrip 10y ago
        But they also do have more of a reputation on the line. Universities are expected to be dignified institutions, moreso than your average news org I would think.
    - 10y ago
khedoros1 10y ago
Even the first line of the article: "Washington State University physicists have created a fluid with negative mass, which is exactly what it sounds like." "Exactly what it sounds like"?? Like...antigravity?? Reads further Ugh. Clickbait.
- kodfodrasz 10y ago
  In classical physics there are 2 types of mass considered (and measured to be equal): 1. gravitational mass used in Newton's Law of Gravity 2. intertial mass used in Newton's Second Law Measurements show that these two kinds of mass properties of an object are equal (are in linear proportion) to a very high precision. This was suspected and even Newton has considered and measured this, but the first really high precision measurements were done by baron Loránd Eötvös[1]. [1] https://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_experiment https://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_experiment
edem 10y ago
There should be some kind of voting mechanism on HN to automate what you did here (like a [hoax] flag) or something. I almost clicked on the bait but reading your comment clarified things. I was excited because this is a prerequisite of the Alcubierre (warp) drive: https://en.wikipedia.org/wiki/Alcubierre_drive https://en.wikipedia.org/wiki/Alcubierre_drive
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- deleted 10y ago
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mrienstra 10y ago
I don't claim to understand any of this, but it sure sounds like you are correct, looking at the terminology. Someone had already added the paper to the "Negative mass" article, so I removed it: https://en.wikipedia.org/w/index.php?title=Negative_mass&diff=prev&oldid=775415593 https://en.wikipedia.org/w/index.php?title=Negative_mass&dif... ... And added it to the "Effective mass (solid-state physics)" article: https://en.wikipedia.org/w/index.php?title=Effective_mass_(solid-state_physics)&diff=prev&oldid=775415322 https://en.wikipedia.org/w/index.php?title=Effective_mass_(s... The bit I removed from the "Negative mass" article said: In April 2017, researchers at Washington State University claimed to have created a fluid with negative mass inside a Bose-Einstein Condensate. I expanded it ever so slightly to read: In April 2017, researchers at Washington State University claimed to have created a fluid with negative effective mass inside a Bose–Einstein condensate, by engineering the dispersion relation. Slightly awkward, but hopefully at least a slight improvement. PS: also added a "disambiguation" thingy at the top ("For negative mass in theoretical physics, see Negative mass."), now realizing it may be of dubious utility.

SubiculumCode 10y ago

Thanks. Too bad it isn't real negative mass. How about imaginary number mass?

deleted 10y ago
[deleted]
nograpes 10y ago
I thought you were joking, but I came across this: https://en.wikipedia.org/wiki/Mass#Tachyonic_particles_and_imaginary_.28complex.29_mass https://en.wikipedia.org/wiki/Mass#Tachyonic_particles_and_i... and was surprised that a plausible notion of imaginary mass exists.
- SubiculumCode 10y ago
  Well being a layman, I had no idea if I was joking or not. :) Actually the idea of negative mass made me wonder if this would open the possibility for FTL space travel...Ran into a comment on the internets somewhere that said "no, because the mass is squared in the relation with energy, but the existence of imaginary masses might" Thanks for the link.
- godelski 10y ago
  Many times people will see an asymptote and say "Hey, what would happen if I crossed that? What would the math and physics look like?" Tachyons are actually a great example of this. Taking the relativistic mass equation and asking "What would happen if I allowed for speeds larger than the speed of light?" Science is more a process of elimination. What does the math say? Can we observe what the math says should happen? Repeat.

vosper 10y ago

Thanks. Every time I see a university press release on HN I jump to the comments first, because there's always someone like you who's helpfully debunked the PR spin (no pun intended) to explain what's actually happening.

dwaltrip 10y ago

It's quite unfortunate that an official university news release seems to purposefully mislead its audience. Or do they really just assume that no one cares about the difference? I find that hard to believe. I suppose incompetence is also a potential explanation.

djsumdog 10y ago
PhD comics really explains this pretty well: http://phdcomics.com/comics.php?f=1174 http://phdcomics.com/comics.php?f=1174 I thought they did a video on the science/news cycle as well, but I can't seem to find it.
- forgotmysn 10y ago
  im sorry, but to me that comic doesn't explain it one bit. the university press in the comic doesn't (appear) to deliberately click-bait the headline, it seems to be a process in your example. Washington State University appears to to have bypassed that process and gone straight for the misleading, click-bait title. This is disappointing because who better than the University Press themselves to try to provide as much clarity as possible. It's not like they don't have access to good sources...
  - TeMPOraL 10y ago
    The incentives of university's PR department aren't to provide accurate reporting on what's happening in said university to other scientists; it's to generate "buzz" around the university so that ultimately it gets more money. In this way, it's no better than regular news sources, and thus the quality is more-less the same.
    - dwaltrip 10y ago
      But they also do have more of a reputation on the line. Universities are expected to be dignified institutions, moreso than your average news org I would think.
  - 10y ago

khedoros1 10y ago

Even the first line of the article: "Washington State University physicists have created a fluid with negative mass, which is exactly what it sounds like." "Exactly what it sounds like"?? Like...antigravity?? Reads further Ugh. Clickbait.

kodfodrasz 10y ago
In classical physics there are 2 types of mass considered (and measured to be equal): 1. gravitational mass used in Newton's Law of Gravity 2. intertial mass used in Newton's Second Law Measurements show that these two kinds of mass properties of an object are equal (are in linear proportion) to a very high precision. This was suspected and even Newton has considered and measured this, but the first really high precision measurements were done by baron Loránd Eötvös[1]. [1] https://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_experiment https://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_experiment

edem 10y ago

There should be some kind of voting mechanism on HN to automate what you did here (like a [hoax] flag) or something. I almost clicked on the bait but reading your comment clarified things. I was excited because this is a prerequisite of the Alcubierre (warp) drive: https://en.wikipedia.org/wiki/Alcubierre_drive https://en.wikipedia.org/wiki/Alcubierre_drive

deleted 10y ago
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deleted 10y ago
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mrienstra 10y ago

I don't claim to understand any of this, but it sure sounds like you are correct, looking at the terminology. Someone had already added the paper to the "Negative mass" article, so I removed it: https://en.wikipedia.org/w/index.php?title=Negative_mass&diff=prev&oldid=775415593 https://en.wikipedia.org/w/index.php?title=Negative_mass&dif... ... And added it to the "Effective mass (solid-state physics)" article: https://en.wikipedia.org/w/index.php?title=Effective_mass_(solid-state_physics)&diff=prev&oldid=775415322 https://en.wikipedia.org/w/index.php?title=Effective_mass_(s... The bit I removed from the "Negative mass" article said: In April 2017, researchers at Washington State University claimed to have created a fluid with negative mass inside a Bose-Einstein Condensate. I expanded it ever so slightly to read: In April 2017, researchers at Washington State University claimed to have created a fluid with negative effective mass inside a Bose–Einstein condensate, by engineering the dispersion relation. Slightly awkward, but hopefully at least a slight improvement. PS: also added a "disambiguation" thingy at the top ("For negative mass in theoretical physics, see Negative mass."), now realizing it may be of dubious utility.