This has been a very long time - 60-70 years - but there's an urban legend of a well-recognized professor of physiology who was carrying out experiments that in

This has been a very long time - 60-70 years - but there's an urban legend of a well-recognized professor of physiology who was carrying out experiments that involved tiny voltages. He couldn't get a good enough ground to wipe out noise. So he bought a 4'x8' (1200x2400 mm, roughly; the size of standard drywall) sheet of copper and had it buried outside his building to provide a nice, steady ground. Soldered to a big fat cable going up to his lab.