An idiom is a group of two or more words that has a different meaning than the real meaning of each word. Choose the one sentence that contains an idiom. The effect lasts just 50 trillionths of a second. But during that brief time, inside the gap, there is no time at all! It's probably taken you about five minutes to read this article. That's three quadrillion (3 with 15 zeroes) beats on an atomic clock. My, how time flies--but it's all in how you measure it! ​