Schrödinger's cat

[BigPaw]

Schrödinger's cat. What is this cat in a box theory suggesting? What does it teach? Do you agree with it?

[pritaeas]

What is this cat in a box theory suggesting?

That observing an experiment may have consequences for it's outcome.

[mike_2000_17]

I encountered a nice programming example of Schrödinger's cat. If you have this code:

int main() {
  int a, b, c;
  a = 1;
  b = 2;
  c = a + b;
  cout << "value of c is " << c << endl;
};

Then, the compiler is allowed to re-order the operations in any way such that the result is the same. So, technically, you don't know (without looking at the assembly code) for sure in what order the operations will be performed (because the value-assignment of a and b could be reversed without any difference in the outcome). But, if you wanted to check that the order was indeed the way it was written in the code, you'd have to add some print-outs:

int main() {
  int a, b, c;
  a = 1;
  cout << "value of a is " << a << endl;
  b = 2;
  cout << "value of b is " << b << endl;
  c = a + b;
  cout << "value of c is " << c << endl;
};

But the problem now is that because you have added those print-outs, the compiler is now obligated to perform the value assignment of a before the first print-out, and then do the assignment of b before the second print-out. Which means that you won't be able to answer the question about the order of operations from the first program, because you've now modified the thing you were trying to observe.

So, the whole point of this "cat in the box" analogy is just to state the reality that some things cannot be observed without affecting the conditions of the experiment to the point that the phenomenon you were trying to observe disappears. This does have some implications on fundamental theories too, but it is mostly a matter of technical problems with experiments. Another example is the problem of observing experiments on zero-point energy, which is characterized by a complete absence of electro-magnetic radiation (i.e., light), how would you go about "shining a light" on what goes on there?

More practically though, it is just a reminder of the fact that you always have to be careful about the consequences of making an observation on the experiment itself. This can be as simple as making sure that the instruments you use do not have contaminant on them, like having some organic residues on a probe that extracts samples of martian soil for detecting traces of life on Mars.

[BigPaw]

I suppose this goes out to others then, would you say that these are the only interpretations? If there are further interpretations, how do they harmonise or contradict? What is it that makes your interpretation, or the interpretation you have learned, believable?

[pritaeas]

Here's another interpretation on 9gag.