To make the most of your time, you should go to bed late and rise early. But that is conventional wisdom. The future may be different because scientists are doing what they can to eliminate our need for sleep. Researchers have been testing a new drug that can keep people awake for days. The drug is called “modafinil” and, unlike other stimulants, it has no side effects. While caffeine can wear off quickly and can make people nervous, the new drug works with the brain so that users continue to feel naturally alert for days on end.