one more energy contraption

[bazaarboy]

Yeah, I looked it up in the end, as it goes. Unfortunately the abstract doesn't really explain what they were looking for or why or what they think they found.

it's not a one-off experiment, plus it's fairly straight forward: particle in vacuum jiggles. there are lots of well described articles that can explain it better than me

Brownian motion is the result of the particles bumping around, so if there are particles/anti-particles popping in and out of existence, then from time to time they will bump into the glass bubble.

hmm i think you're mixing concepts here, particles and antiparticles refer to tiny structures with opposite electrical charges - they don't "pop in and out of existence"!!! any more than a larger structure can vanish, although it would explain where the TV remote goes sometimes...
you're referring to anti-matter maybe?

 

[Vonhelmet]

it's not a one-off experiment, plus it's fairly straight forward: particle in vacuum jiggles. there are lots of well described articles that can explain it better than me

Yes, but I want to know why it jiggles. You say it jiggles on it's own. I say an "external" force is moving it.

hmm i think you're mixing concepts here, particles and antiparticles refer to tiny structures with opposite electrical charges - they don't "pop in and out of existence"!!! any more than a larger structure can vanish, although it would explain where the TV remote goes sometimes...
you're referring to anti-matter maybe?

You already said you're not a chemist or physicist and now you're proving it. Yes, I am talking about anti-matter. Every particle has an anti-matter counterpart - its anti-particle. The anti-particle does indeed have the opposite electrical charge, so you're right there. The most common example is probably the electron and positron. Positrons are routinely created in radioactive beta decay, but are quickly destroyed when they hit a passing electron. Most crucially, in a vacuum particle/anti-particle pairs are constantly appearing and disappearing. This is a well acknowledged phenomenon. They spontaneously appear out of nothing and then they quickly collide again with one another - their opposite charges mean they are directly attracted to each other - and they disappear into nothing again. I am putting it to you that that is the reason for the Brownian motion in the quantum vacuum in the article that you cited.

 

[bazaarboy]

vonhelmet, you're complicating what is a straight-forward phenomenon

Brownian motion has nothing to do with anti matter or electrical charges. I'll attempt a more detailed explanation:

Say you have a small particle of dust in a fluid eg water or air.

The structure of the particle is made from molecules held together strongly enough so that the particle doesn't just disintegrate. However the constituent molecules vibrate, and move in random directions, each has its own motion vector, which lasts fractions of a nanosecond.

Look at the first image below. At this point in time the product of all the motion vectors cancel each other out. This means there is no net movement of the particle.

About half a nanosecond later, and completely randomly and by accident, the motion vectors generally point upwards:

This means that the particle will move upwards, until a new net vector results in a new direction of motion. That's it - Brownian Motion...

 

[Vonhelmet]

That's not Brownian motion. That's not even physically accurate. Molecules in a solid don't move. If they do, it's a fluid, not a solid. Likewise, atoms in a molecule can't move relative to one another. A solid particle is essentially inert.

Atoms or molecules in a fluid are constantly moving. They bounce around but crucially they don't change direction unless they hit something or are interfered with by, say, a magnetic field. It is all these particles in the fluid that cause the Brownian motion. As all the particles move around they strike the solid particles (lipids in your video on page 1) and the net effect of the countless collisions causes a net movement in the solid, which constantly varies over time as all the fluid particles bounce around.

You appear to be suggesting that a particle could change direction on its own dependent on the vibrations of it's molecules. This is impossible, per Newton's laws of motion, specifically law number one, which states that a body remains at rest or at constant velocity unless acted upon by an external unbalanced force. The motion of the individual molecules in a particle, were such a thing even possible, couldn't cause it to move or change direction as that is internal to the particle. Any resultant motion would be akin to one pulling oneself up by one's bootstraps - impossible.

My point with the antiparticles business was that you cannot have Brownian motion without a fluid. If it is occurring in a vacuum it is not Brownian motion. It could be like Brownian motion, but it is not caused by Brownian motion in the solid itself - the glass bead in the quantum vacuum - because you can't have Brownian motion in a solid. The reason I brought up the anti-particles business is because it could be that the observed motion is due to anti-particle pairs striking the glass bead and causing it to move, thus appearing tongi e the same effect as Brownian motion.

Seriously, go read the wikipedia article on Brownian motion, particularly the part where it describes the motion as:

the assumably random movement of particles suspended in a fluid

 

[lord filbuster]

stuff

Pretty sure that isn't right. Brownian motion of small particles in fluid is caused by the fluid molecules striking them, applying a tiny random force to the particle. Also, the article you quoted even says that the glass microbubble is in a vacuum with a pressure of 1e-4 torr, meaning it isn't a perfect vacuum. It is simply being struck by molecules. Even if you could get a perfect vacuum, the particle would still be struck by virtual particles, and probably still exhibit brownian motion.