海阔天空 [- - tiān kōnɡ]①(形容大自然的广阔) as boundless as the sea and sky [heavens]; as broad as the sea and sky; in open sea and sky; endlessly vast; The sea is wide and the sky spacious. ②(比喻想像或说话无拘束、无边际) discursive; without restriction or limit; straying from the subject; rambling unrestrained and far-ranging; talk at random; indulge in loud and empty talk：•¶海阔天空地漫谈一通， 不解决任何实际问题 indulge in far-ranging rambling discourse without solving any practical problem
•¶海阔天空地聊个没完 have a rambling chat about everything under the sun