Since you won't have a Google Account with which to access the group, you won't be able make posts using the web interface. You will only be able to respond to posts or create new topics by sending mail to arch-r...@googlegroups.com.
You'll still be able to browse the group through the web interface like any other anonymous user.
To join this list without forking over your privacy to Google, please contact the administrator at ad...@archreactor.org, and we'll process your request as quickly as possible. Please note that for verification reasons you must send the request from the address with which you'd like to join.