pulsate

"To be is to be the value of a variable." -Willard Van Orman Quine It's the end of the week once again, and the very end of our Year In Space 2014 Wall Calendar giveaway! So for this week's Ask Ethan column, after dipping into our question/suggestion box, I'm very pleased to let Vera from Italy know that her question was the winning one, as she asked: I saw the video you posted about  the variable star RS Puppis, by the Hubble Space Telescope, and I really would like a post about what exactly are variable stars. Thank you very much Ethan!! :-) So -- no burying the lede here -- there was a…