whether there is/could be a way to tell if an entangled particle has been/has not been collapsed without collapsing it in the process

Question

whether there is/could be a way to tell if an entangled particle has been/has not been collapsed without collapsing it in the process

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Answer 1

There is such a thing as quantum error correction. You can tell if your wavefunction has collapsed or (more precisely) *decohered* (lost purity), by measureing *some* of its properties and making appropriate adjustments. You just need to make sure that your measurement only concerns properties you don’t care about.