Allen D Concerning "Title:Quantum tunneling cantilever accelerometer" -- thank you for your agreement. My reading of this document tells me that it remains, for all its sensitivity, a mass on a spring. It may indeed register the tiniest of accelerations, but it will still read zero if it is not being accelerated. Wouldn't be much use if it did would it? As I don't have any idea how you expect it to read acceleration in free fall, why don't you favour us all with a short, concise, lucid explanation of how you understand this happening. I'm sure we'd all appreciate that. And as you raised the matter, a similar explanation of the uses of your favourite super-sensitive gyroscope would, I'm sure, also be appreciated by all. In case you have any doubts here, for mine, Regner said it all. Paul D Get the name you always wanted with the new y7mail email address. www.yahoo7.com.au/y7mail