A Quote from Portal 1
GLaDOS
Momentum, a function of mass and velocity, is conserved between portals. In layman's terms, speedy thing goes in, speedy thing comes out.
More quotes from Portal 1
When I said "deadly neurotoxin," the "deadly" was in massive sarcasm quotes. I could take a bath in this stuff. Put it on cereal, rub it right into my eyes. Honestly, it's not deadly at all... to me. You, on the other hand, are going to find its deadliness... a lot less funny.
The Enrichment Center promises to always provide a safe testing environment. In dangerous testing environments, the Enrichment Center promises to always provide useful advice. For instance: the floor here will kill you. Try to avoid it.
Time out for a second. That wasn't supposed to happen. Do you see that thing that fell out of me? What is that? It's not the surprise. I've never seen it before! Never mind, it's a mystery I'll solve later... by myself, because you'll be dead.
Congratulations, the test is now over.
All Aperture technologies remain safely operational up to 4000 degrees kelvin. Rest assured, that there is absolutely no chance of a dangerous equipment malfunction prior to your victory candescence. Thank you for participating in that Aperture Science Enrichment activity. Goodbye!
The Enrichment Center reminds you that the Weighted Companion Cube will never threaten to stab you and, in fact, cannot speak.