[Robert J. Bonacino]

Today in the lab of my department I was working with a quartz reactor, when in one of the pipes I measured a negative pressure of -2.5bar for a few seconds, the pipe become, strangely, very cold and the reactor went down.

I must say that the pipes are usually at a pressure near to 40 mmHg.

I ask if it is possible to reach a pressure like that i measured: when someone want reach vacuum state in a pipe, is it possible to create a state where a negative pressure can exist?

Moreover I explain better, in state like black holes, supernovas, other relativistic quantistic phenomena is it possible to arrive to these conditions?

I found something about dark energy, could you explain me also this?

R.J.B.

[Borek]

Experimental error IMHO, no such thing as negative pressure.