Pay for stuff by waving a mobile phone at a cash register: Apple’s version of that was unveiled with much fanfare this month. But there may be a problem, and that problem is not a technical one but a business one. More on that. And later today, we’ll hear how Twitter did last quarter. So, how much time does the company have to find a way to make money? Plus, the United Nations reports  1.3 billion tons of food gets thrown out every year. And now, figuring out how to keep perfectly good produce and leftovers out of landfills has become fertile ground for tech innovators.