Gamma rays are not used for communication.
-- We have no safe way to generate them.
-- We have no cheap way to detect them.
-- We have no way to impress information on them (modulate them).
-- They're dangerous.
Otherwise they're ideal for communication.
True. Mobile devices need to work within limited screen space. Mobile devices are designed to be portable and designed to be carried around without hassle. Mobile devices are used for personal activities such as talking privately, chatting and many more that is why it is designed to be small.
Nothing, it will just keep sending you annoying notifications that become more and more frequent, i would just confirm it if i were you
Which field TCP header is not typically used in modern networks