How have you proved that you were right? You simply told me that you're "a trained and certified fluid power and pneumatic technologist and vacuum is negative pressure" and basically told me to shut up. How does that help anyone?
Sadly I didn't learn anything other than it confirmed that you often get defensive with an attitude when someone questions your input (regardless if you was right or wrong). You expect everyone to simply believe something without going into it a bit?
We are here to learn and help each other.
I did a search online and I often seen the phrase that it is "misleading" to refer to vacuum as negative pressure because pressure is "always positive".
You didn't offer any explanation to it.
I said I would refer to it as vacuum because that is exactly what it is, vacuum. I could be wrong, but I thought that generally in the real world, people refer to pressure that is often measured in PSI.
I was was trying to help the poster clarify any confusion, which is also what I think ricksza was trying to do as well.
Sad day when you can't help others without it turning into this.