You'll be able to say TIL (today I learned) at What If? answering your hypothetical questions with physics, every Tuesday. What If? is a subsection of XKCD, a webcomic of romance, sarcasm and language. You might also enjoy XKCD Blag.
Quote: "You can use heat flow to come up with simple rule of thumb: If an unused charger isn't warm to the touch, it’s using less than a penny of electricity a day. For a small smartphone charger, if it’s not warm to the touch, it’s using less than a penny a year."
