Fact: The Pope can't be an organ donor
Pope Benedict XVI was issued an organ donor card in 1970. Once he ascended to the papacy in 2005, the card was invalid, reports the Telegraph. According to the Vatican, the Pope's entire body must be buried intact because his body belongs to the universal Catholic Church. Don't miss 27 other things Rabbis, priests, and ministers won't tell you.

Fact: Albert Einstein's eyeballs are in New York City
They were given to Henry Abrams and preserved in a safety deposit box. Abrams was Einstein's eye doctor. He received the eyeballs from Thomas Harvey, the man who performed the autopsy on Einstein and illegally took the scientist's brain for himself.

Fact: Adult cats are lactose intolerant
Feeding your cat milk could be making them sick. Like some humans, adult cats don't have enough of the lactase enzyme to digest lactose from milk, causing them to vomit, have diarrhea, or get gassy. Cats only have enough of that enzyme when they're born and during the early years of their life. Find out why cats are also afraid of cucumbers.

Fact: Wimbledon tennis balls are kept at 68 degrees Fahrenheit
The temperature of tennis balls affects how the ball bounces. At warmer temperatures, the gas molecules inside the ball expand making the ball bounce higher. A tennis ball at lower temperatures causes the molecules to shrink and the ball bounces lower. To make sure the best tennis balls are used, Wimbledon goes through over 50,000 tennis balls. Next, find out the 11 genius ways that tennis balls can actually make your life better.