A Stable Plasma Ring Has Been Created In Open Air For the First Time Ever (futurism.com)

New submitter mrcoder83 shares a report from Futurism: Engineers from the California Institute of Technology (Caltech) have been able to create a stable plasma ring without a container. According to the Caltech press release, it's "essentially capturing lightning in a bottle, but without the bottle." This remarkable feat was achieved using only a stream of water and a crystal plate, made from either quartz and lithium niobate. The union of these tools induced a type of contact electrification known as the triboelectric effect. The researchers blasted the crystal plate with an 85-micron-diameter jet of water (narrower than a human hair) from a specially designed nozzle. The water hit the crystal plate with a pressure of 632.7 kilograms of force per centimeter (9,000 pounds per square inch), generating an impact velocity of around 305 meters per second (1,000 feet per second) -- as fast as a bullet from a handgun. Plasma was formed as a result of the creation of an electric charge when the water hit the crystal surface. The flow of electrons from the point of contact ionizes the molecules and atoms in the gas area surrounding the water's surface, forming a donut-shaped glowing plasma that's dozens of microns in diameter. Caltech posted a video of the plasma ring on their YouTube channel.

Comments

1950s technology

[boudie2]

"Gharib’s team also noticed another peculiar phenomenon: the plasma ring emitted distinct radio frequencies, as evidenced by the high levels of static the engineers’ mobile phones picked up during the experiment. “That’s never been seen before. We think it’s because of the piezo properties of the materials that we used in our experiments,” Pereira explained."
Sounds to me like he's never heard of the plasma speaker.
https://en.wikipedia.org/wiki/...

Re:1950s technology

[arth1]

But that is far from the only possible source of RF noise

Indeed.
You're hitting crystal plates with a water jet. Oscillating crystals causing electromagnetic noise was pretty much how radio transmitters were born.

"kilograms of force"

[Pfhorrest]

The hell kind of weird bastardized units are these writers using? Kilograms are mass. Newtons are force. Do you mean 9.8N, which is about the force of 1kg under 1g (g-force, not grams) of acceleration?

Re:"kilograms of force"

[mark-t]

The kilogram and kilogram-force are different units, even if the latter often gets lazily abbreviated in name to the former

That is true, yes. It would be more correct for me to say that the *names* of the units are the same than it to just say (as I had) that the units are the same, but for some reason I didn't think of putting it that way when I was responding, above.

As for Newton having nothing to do with how the kilogram came to be defined today, I know that Newton actually used imperial units. The kilogram-force unit is basically just a metric equivalent to the notion of the concept of pounds of force, which would have actually been the primary expression for the notion of force prior to Newton (long before it was understood that force was actually the product of acceleration and mass, and not just the mass). The creation of the SI unit called a Newton deprecated the notion of using a weight/mass unit to describe force entirely, but the reference to the force experienced by a given mass at 1G persisted, and is still frequently used because it is often more intuitively understood by people without a physics background.

So the expression "kilograms of force" always explicitly refers to the kilogram-force unit, but it is redundant to say that so many kilograms-force of force were used to do work XYZ, so the 'force' suffix on the unit is often dropped from the unit name itself. Since the word appears almost immediately afterwards anyways, no ambiguity about the term's usage remains, but when you see "pounds of force" or "kilograms of force", the actual units being measured to are pound-force and kilogram-force.

Re:"kilograms of force"

[ortholattice]

What is curious is that they needed precisely 632.7 kilograms of force per centimeter [sic], to 4 significant figures. Even more remarkable is that this evaluates to almost exactly 9,000 pounds per square inch (8999.1 psi to be precise).

Re:Now the must move elsewhere to continue work

[Opportunist]

If you had told me half a century ago that there could be any land that might eclipse the US in terms of technology and progress, I would have called you insane. Remember? The time when the US built those huge rockets to go where nobody has gone before?

20 years ago I would probably have said something along the lines of "Yeah, Japan. but they can't compete in raw production power"

Today, I'd probably ask if there is actually still any research and development done in the US, and whether there is actually any US-owned corporation left, or whether the Chinese are finally done taking over.

Measurements!

[Anonymous Coward]

"generating an impact velocity of around 305 meters per second (1,000 feet per second)"

Ok, the actual science was done measuring meters per second, the press release rounds it to a nice round number of 1000f/s for American audience, and then that rounded number is converted to a quite exact figure of 305m/s.

In the actual paper, the experiment was done with a wide range of velocities. Over 200 m/s was required velocity to generate the effect.

Re:632.7 kilograms of force

[Megane]

How long is that in parsecs? I want to figure out how many Kessel runs that is.

WTF /.

[drewsup]

I submitted this FOUR DAYS AGO, with links to the Caltech aticle!

Re:WTF /.

[Anonymous Coward]

It took 4 days to put all those errors in the summary.

kilograms as a unit of force...

[CrimsonAvenger]

They're not. Get over it.

SI has a perfectly good unit of force (the newton). It will be really great when SI advocates actually start using SI, rather than bastardizing it with things like "kilograms of force"....