When trying to go to the highlighted discussion Ask Me Anything 12th July: guest's introduction and questions my chromium browser gives an error message,
Your connection is not private Attackers might be trying to steal your information from meta.physics.stackexchange.com (for example, passwords, messages, or credit cards). NET::ERR_CERT_COMMON_NAME_INVALID''
This server could not prove that it is meta.physics.stackexchange.com; its security certificate is from *.stackexchange.com. This may be caused by a misconfiguration or an attacker intercepting your connection.''
Something similar on firefox.