Promise and controversy continues to surround string theory as a potential unified theory of everything. In the latest episode of The Joy of Why, Cumrun Vafa discusses his progress in trying to find ...

The plus sign (+) means "ADD" in programming and on calculator keyboards. For example, 10 + 7 means 10 added to 7. It is also used as a concatenation symbol for text fields. For example, city + ", " + ...