The Uncertainty Principle is the fact then if you try to measure exactly where something is and where it's going, there is a minimum level of uncertainty that you cannot better. Basically, this is because any measurement method disturbs what it is trying to measure.

The dead/alive cat is something else. Quantum theory is a theory about probability. You can predict the probability of what something is going to do very accurately, which is fine when what you're interested in is made up of a lot of particles and the average of what they do is good enough, but vague for a single particle. One interpretation is that it's behaviour only becomes certain when it is observed. The cat is a thought experiment where the fate of a cat in a box depends on what a single particle does. The theory is that you only know if the cat is alive or dead - "the probability wave collapses" - if you open the box to observe it.

My opinion is that the cat is also an observer and knows if it is alive.

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"The truth may be out there, but lies are inside your head" Terry Pratchett