Why did Bart age overnight? How old is he now?
During Infinite Crisis, Bart and other speedsters trapped Superboy Prime on another earth beyond the speed force. Time flowed at a different rate there. Four years passed for Bart, while only hours or days passed for the rest of the world. In The Flash: The Fastest Man Alive #1, Bart says that “a year ago” (i.e. right before Infinite Crisis) he was 16. He was 20 when he returned, and it’s now one year later, making him 21. If you want to get technical, though, he’s probably only around 10. Bart was born with a super-fast metabolism, and grew to adolescence in only three years before it settled down to a normal rate. (A hyper-fast virtual reality environment helped him develop mentally and grow up sane. See Impulse: Reckless Youth for the story.) It’s not clear how much time passed between Zero Hour and Infinite Crisis, so make it 3 + X+5. Plus he’s a time traveller, so his birthday won’t come around for almost 1,000 years…
