Is Schrödinger's Cat really simultaneously alive and dead?
No, it is not. The Copenhagen Interpretation of quantum mechanics essentially states that an object in a physical system can simultaneously exist in all possible configurations, but observing the system forces the system to collapse and forces the object into just one of those possible states.
1. Schrödinger disagreed with this interpretation.
2. He invented the thought experiment with the 50-50 chance of a decaying particle triggering poison release and killing the cat, to show that the Copenhagen Interpretation was flawed, because a cat cannot both be alive and dead.
3. Many people incorrectly assume Schrödinger supported the premise behind the thought experiment. He did not. His entire point was that it was impossible.
4. Modern experiments have revealed that while quantum superposition does work for tiny things like electrons, larger objects must be regarded differently.