7 Actors Who Made a Difference

Many famous actors aren't satisfied with their stardom, and they want to do something more. Over the years, a handful of actors have truly made a difference in the world "“ and in some cases, they did so in ways that you wouldn't expect. From inventors to troublesome mistresses to Kevin Bacon, here are seven examples.

1. Lola Montez "“ She Ended an Empire

Few 19th-century entertainers were as colorful as Irish actress and dancer Lola Montez (born Eliza Rosanna Gilbert), who appeared in Broadway shows and performed around Europe as a "Spanish" dancer. She was also banished from Warsaw for publicly criticizing the ruling despot, attacked a newspaper editor in Australia when he published a bad review of her show, gossiped with the Tsar, and was the lover of composer Franz Liszt. In her most notorious episode, she became mistress of King Ludwig I of Bavaria in 1846, despite a 35-year age difference. Her fierce temper and arrogance made her very unpopular with his subjects, who were furious to see the influence she held over the famously amorous king, especially when he made her Countess of Landsfeld. Noble or not, her scandalous behavior contributed to the fall from grace of the popular king (who had ruled for 22 years), inspiring thoughts of revolution. Ludwig was forced to abdicate in 1848. Montez died in 1861 at age 39.

2. John Wilkes Booth "“ The President's Toughest Critic

For the record, Edwin's career went from strength to strength, despite the stigma of being an assassin's brother. His later renditions of Othello in Britain, alongside the great English actors Sir Henry Irving and Dame Ellen Terry, won large audiences and rave reviews.

3. Florence Lawrence "“ Auto Pioneer

In her spare time, however, Lawrence was a tinkerer. The daughter of inventors, she was one of the first car-owners and a true automobile geek, inventing such accessories as the "auto signaling arm," a forerunner of the turn signal (she placed an arm on the back of the fender that could be activated with the push of a button) and the automatic "full stop" sign, an early version of brake lights.

Sadly, like Erno Rubik and the inventor of the wheel, her genius didn't extend to filling our patent forms, so others became rich by enhancing her inventions. Nor did she realize that popular film stars could demand ridiculously high salaries. She eventually died in poverty in 1938.

4. Zeppo Marx "“ The Cleverest Brother

Of all the Marx Brothers, the youngest, Herbert (alias Zeppo), got the raw deal. In the early movies, he played the straight man who usually didn't do much. He left the team when they moved to MGM in 1934 (when, it so happened, their box-office improved greatly). But before labeling him as "the boring brother," note that, as the baby of the family, he was stuck with that role. The others said that, in private, he was easily the funniest Marx. When Groucho was in hospital during one of their vaudeville shows, Zeppo would take over his role "“ and did it so well that some in the audience thought he was the "real" Groucho. (The cigars made him sick, however.)

Moreover, he was a brilliant engineer who always had a love of motor cars and machines. After leaving the Marx Brothers, he formed an engineering company, Marman Products, which manufactured coupling devices for aircraft. During World War II, most of his work was top-secret, but it was said that one of Marman's devices was used to hold the first atom bombs in place. Some years later, he invented and patented a wrist device for cardiac patients that measured their heartbeats, sounding an alarm if the wearer went into cardiac arrest.

5. Hedy Lamarr "“ Mastermind of the Wireless

There must be something about movie stars and inventiveness. Hedy Keisler made history with her teenage nudity in the daring Austrian film Ecstasy (1932), and won even greater fame when she moved to Hollywood and took the name Hedy Lamarr. In films like Algiers (1938) and Samson and Delilah (1950), she was known as one of the most sultry and beautiful women in the movies.

But Lamarr had brains as well as beauty. During World War II, she invented a radio guidance system for torpedoes, which she developed with the help of another clever Hollywood friend, composer George Antheil. Known as "frequency hopping," it consisted of two synchronized pianola rolls, allowing technicians to switch control frequencies so the torpedo could escape enemy tracking. Though they received a patent in 1942, the War Department declined to use it. It was later adapted for satellite communications, and is now widely used in cellular phones and other modern technology. As the patent had expired before most of this, neither Lamarr nor Antheil profited from their cleverness, but Lamarr was given due recognition before her death in 2000.

6. Eva Peron "“ Argentina's National Heroine

7. Kevin Bacon "“ He Might Save the World Someday

Of course, the idea of networking (getting a job from the friend of a friend) was nothing new, but around the time Six Degrees of Kevin Bacon originated, scientists Duncan Watts and Steve Strogatz were exploring the world of network theory, a new field of scientific research suggesting that large groups (be they viruses or football crowds) don't connect randomly, but are structured around nodes. The theory was all well and good, but they needed to prove it by studying some real networks. Strangely, few networks had been mapped "“ but then they discovered The Oracle of Bacon, a cheat-sheet website for the Kevin Bacon game, created by student Brett Tjaden and linked to the Internet Movie Database.

Tjaden's program, in the hands of the scientists, advanced the research considerably. Network science principles have already led directly to the capture of Saddam Hussein, as the military moved through the dictator's social networks. But there are hub networks everywhere from computer chips to human cells. In the future, it is hoped, scientists will map out networks to combat terrorism, predict pandemics, even cure cancer. When this happens, remember to thank a certain Hollywood star for an off-hand comment he once made in an interview.