Sort of but not exactly dangerous

As we are reassurred by Kenneth Chang today in The New York Times

... it's not even really a black hole...

The Brookhaven mini-black hole, if it existed, would have nothing to do with gravity. Brookhaven's Relativistic Heavy Ion Collider, RHIC (pronounced rick) for short, accelerates gold nuclei - atoms stripped of their surrounding clouds of electrons - to 99.995 percent of the speed of light and then slams them together, head-on.

The calculations of Dr. Horatiu Nastase, a professor of physics at Brown, suggest that in the trillion-degree fireball of a collision, the so-called "strong force" that holds protons and neutrons together, would briefly create a black-hole-like vortex that swallowed part of the gold.

"The reason it acts like a black hole is because it eats up stuff and it only gives out radiation," Dr. Nastase said.

He added that even if his supposition was correct, these black holes posed no danger to Brookhaven or the planet. "It would be very hard to create anything bigger," he said. That is because black holes do not last forever. Dr. Stephen W. Hawking of Cambridge University showed that they gradually burp out what they swallow. And a tiny black hole spews energy far faster than it swallows and will evaporate almost instantly into nothing.

In a normal black hole, the energy comes back out as photons, particles of light, what is called Hawking radiation. In a strong force mini-black hole, the radiation would come out as particles known as pions. Because of the differences between gravity and the strong force, a strong force black hole would inevitably fall apart, Dr. Nastase said...

Let me get this straight: "The collisions of gold nuclei produce matter as it existed shortly after the Big Bang. In the everyday universe, protons and neutrons in atomic nuclei are made of smaller particles known as quarks that are held together by the strong force, and because the strong force is so strong, it is ordinarily impossible to pull out a single quark.

But physicists expected that at ultrahot temperatures the bindings holding the quarks together would loosen and dissolve into a new state of matter, the quark-gluon plasma. (Gluons are the particles that carry the strong force, just as photons are the particles that carry the electromagnetic force.)

Five years later, however, physicists are still holding off from claiming they have made a quark-gluon plasma. That is in part because the result of the collisions looks more like a liquid than a gaseous plasma.

"It doesn't resemble what our naïve expectations for quark-gluon plasma were," said Dr. William A. Zajc, a professor of physics at Columbia and the spokesman for one of the detectors on the collider."

You set up conditions to produce a quark-gluon plasma, and instead you get something that behaves for a very short time like a black hole.

You don't understand it. You admit it.

Umm... so... maybe you should conduct these experiments a safe distance away from the only planet we have right now?

Before DARPA decides to make a weapon out of it?