tag:blogger.com,1999:blog-10666456.post774312695628495360..comments2024-01-08T15:04:49.691-06:00Comments on Dean W. Armstrong: Early September ISS Shuttle passes in ChicagoDean W. Armstronghttp://www.blogger.com/profile/01775475819534188248noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-10666456.post-85290480018064737202009-09-11T16:46:33.654-05:002009-09-11T16:46:33.654-05:00Dear Dean W. Armstrong
I was searching the net for...Dear Dean W. Armstrong<br />I was searching the net for ion chamber and radioactivity measurement.<br />Found your blog and have read your article about “A simple ion chamber to measure radioactivity”.<br />It is so interesting and useful.<br />Congratulation.<br />I have a scientific question and I don’t know is it ok to ask you?<br />If know and possible, please help me.<br />Let me tell you what is the story.<br />I live in a historical city. using metal detector to find ancient coins, metals,….<br />But I have experienced a phenomenon at least strange for me.<br />Metal detector can find old(ancient)metals more deeper than fresh metals under the soil.<br />But when I touch the soil or move it or take out that metal from the soil,<br />Metal detector can not find same target from previous distance.<br />For example detector can find an old silver coin from 40 cm but if I change or move the soil on top of or around the target or take it out, the detector just can find it from 20 cm.<br />This is famous between people as “gold gas”,” silver gas”,…<br />Some times this phenomenon causes false signal or lead to false position.<br />I don’t know what is this. ionization? electrostatic field?....<br />Is it detectable by another techniques? is it traceable from far by another instruments?<br />Some sites named as “ghost wave” or “ghost signal” but no explanation.<br />I couldn’t find any suitable answer for it.<br />If possible, would you please direct me?<br />Thank you<br />Best regards<br />Behnam <br />Behnam5757@yahoo.comAnonymousnoreply@blogger.com