I was watching a video on the arrow of time, and it got me quizzing ... does the present i.e. now actually exist? The past can be said to be something that happened at a certain time ... i.e. a second ago, a minute ago etc. The future can be said to be something that may/will/could happen and a time can be linked to that too ... "Grandma said she will ring in 30 minutes". But what about the present? If the present is what's happening at this moment in time, how do you define, or measure, the moment? Is it what's happening this second? If it can be a second why can't it be a millisecond, or a nanosecond? Or an amount of time that is to quick for us to even realize? Which would then mean by the time we've thought about what's happening in the present it becomes the past and then there is no present. Sorry if my terminology is incorrect, I'm not a physicist, although I do have a deep interest in physics.