Firstly, I want to preface that I am not English-speaking. I apologize in advance for my probable spelling mistakes... We all know the experience that consists of rubbing a Bic pen in one's hair and then using the pen to life some little pieces of paper. By rubbing the Bic, you pull the electrons...

According to my Halliday-Resnick, the period of a pendulum clock can be kept constant with temperature by attaching vertical tubes of mercury to the bottom of the pendulum. How does this work? My guesses: Air resistance somehow changes with the temperature of the air, and this is offset by mercu...

Related and sort of a follow-up question to: If string theory is inconsistent with observations, why hasn't it been rejected yet? From the answer to that question, string theorists are aware the theory is inconsistent with cosmological observations, but they are not rejecting the theory, because ...

Take a look at this video: https://www.youtube.com/watch?v=Cg73j3QYRJc It shows that when 2 springs in series are transformed into 2 springs in parallel the weight goes up. But I'm interested in what happens in that split-second after cutting the blue cord but before the green and red ropes becom...

From the Wikipedia page about Ergospheres: As a black hole rotates, it twists spacetime in the direction of the rotation... Does this "twisting up spacetime" add up over time in any measurable way? Or do I take a metaphor too literal? What I mean by "adding up" is if we'd assume that spacetime ...