n In the 1940s, Austrian-born actress Hedy Lamarr co-invented a communications system intended to make radio-guided torpedoes harder for enemies to detect. The invention was the basis of the “spread-spectrum” technology used today in cordless telephones and WiFi connections. (Thanks to Art Leone of Seattle.)

No peeking: The interior pages of American passports feature background illustrations of U.S.:


B) Presidents

C) State seals

D) Postage stamps

Friday’s answer: According to the Arthur Conan Doyle story “His Last Bow,” Sherlock Holmes wrote the “Practical Handbook of Bee Culture” in his retirement.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.