**Ask a monkey a physics question thread**

[OngBonga]

Back to physics...

http://www.bbc.co.uk/news/science-environment-39642992

What the actual fuck is negative mass? I've come to understand mass as resistance to acceleration. The "heavier" something is, the more resistance it has. Something with zero mass, ie a photon, has no mass because it has no resistance to acceleration... it always moves at c, so does not experience a change in state of motion, thus, no mass.

So how can negative mass be explained in inertial terms?

[BananaStand]

Back to physics...

http://www.bbc.co.uk/news/science-environment-39642992

Am I understanding this correction if I'm envisioning this discovery leading to the development of tractor beams?

[OngBonga]

Am I understanding this correction if I'm envisioning this discovery leading to the development of tractor beams?

I'm not understanding it at all right now. I'm hoping mojo can explain this in inertial terms so I can get my head around it.

[BananaStand]

I'm not understanding it at all right now. I'm hoping mojo can explain this in inertial terms so I can get my head around it.

I'm kind of focusing in on the part where if you push an atom, it moves toward you. And I'm envisioning US satellites firing something at North Korean missiles that makes them fly upwards and off into space.

[OngBonga]

I'm kind of focusing in on the part where if you push an atom, it moves toward you. And I'm envisioning US satellites firing something at North Korean missiles that makes them fly upwards and off into space.

Obviously this is speculation because I have no fucking idea what we're even talking about, but I'm assuming that the amount of force required to propel something is the same... just in the opposite direction. So I'm not sure it has potential applications when it comes to propulsion.

For argument's sake, let's say it takes 100 of energy to propel something into orbit, with the force applied underneath the object. Well, we still need 100 energy, we just apply the force to the top instead.

However, the term "fuck knows" keeps popping into my head.

[MadMojoMonkey]

Back to physics...

http://www.bbc.co.uk/news/science-environment-39642992

What the actual fuck is negative mass? I've come to understand mass as resistance to acceleration. The "heavier" something is, the more resistance it has. Something with zero mass, ie a photon, has no mass because it has no resistance to acceleration... it always moves at c, so does not experience a change in state of motion, thus, no mass.

So how can negative mass be explained in inertial terms?

lol
"not the apparatus used in the latest research"
Editor was all, "I don't care. Put a sciency picture on this article, dammit!"

***
They're saying that it's the inertial mass that is negative (no mention of gravitational mass). They're not saying any known laws of physics need revision.
So F = ma, still. (bold letters used to indicate vectors)
F doesn't change, a doesn't change, only the sign of m changes. The result is that the applied force causes acceleration in the opposite direction of the force.
Meaning that if I push something with negative mass, it will move toward me, not away from me, as expected.

They're not saying any single particle behaves this way. They're saying there is a region of the Bose-Einstion Condensate which behaves in this way.
It sounds like it's a property of the system, and not of the particles.

This still needs peer review and replication as far as I can tell.