11-06-2018, 08:14 AM
Interesting article here by a chap called David Berry, quoting a reply from Lucas in 1966 about the reasons for positive or negative earth.
The link downloads a pdf file.
https://www.google.co.uk/url?sa=t&source...gw359cpBtZ
The link downloads a pdf file.
https://www.google.co.uk/url?sa=t&source...gw359cpBtZ