FTP, name this idea from quantum mechanics often conflated with the observer principle, which states that there is an upper bound for the accuracy of measuring a particle's position and momentum.
Its formulator explained it by building a microscope using long wavelength and short wavelength light to detect an electron, and it was developed while its formulator was working with Niels Bohr in Copenhagen.  FTP, name this idea from quantum mechanics often conflated with the observer principle, which states that there is an upper bound for the accuracy of measuring a particle's position and momentum.
Its formulator explained it by building a microscope using long wavelength and short wavelength light to detect an electron, and it was developed while its formulator was working with Niels Bohr in Copenhagen.  
Heisenberg {Uncertainty principle}