Classical unified field theories Classical unified field theories Since the 19th century, some physicists, notably Albert Einstein, have attempted to develop a single theoretical framework that can account for all the fundamental forces of nature – a unified field theory. Classical unified field theories are attempts to create a unified field theory based on classical physics. In particular, unification of gravitation and electromagnetism was actively pursued by several physicists and mathematicians in the years between the two World Wars. This work spurred the purely mathematical development of differential geometry. This article describes various attempts at formulating a classical (non-quantum), relativistic unified field theory. For
Unified voicemail Unified voicemail Unified voicemail is the combination of different voicemail bearers into a single voicemail system. Using dedicated DID /DDI numbers for each mailbox, the mailbox can be used on a variety of devices and end-points. This is similar to what GSM providers use for their voicemail systems. Mobile phones and traditional analog phones need to support conditional call diversion to enjoy unified voicemail. Unified voicemail can be extended into unified messaging as already used. Some telephone users have several telephone accounts, which may include home, work, mobile, and SIP numbers. Unified voicemail provides a single voicemail for several accounts.