You invite your friends over to watch an NBA basketball playoff game on TV. There are plenty of sodas in the refrigerator, the popcorn is popping, and you are all set to watch the big game. You turn on the TV set, and all you get are fuzzy images on the screen. Is this plain bad luck or is it Murphy's Law at work? Murphy's Law states: If anything can go wrong, it will.Similar situations occur all the time. When you're in a hurry to open the door and you try several keys on the key ring , the last remaining key is usually the one that works. When you get in a line at the supermarket, you find you've chosen the slowest one, and it just doesn't move. Is this bad luck or coincidence? According to British physicist Robert Mathews, it's neither one nor the other. He explains that our Selective memories tend to remember the bad episodes more readily than the things that usually work out. Also, the law of probability is more against us than in our favor in many situations. For example, in the supermarket with five cashiers, the chances of getting the fastest lane are 20 percent, and 80 percent for a slower lane.Mathews became a popular scientist when he proved thata piece of toast doesn't necessarily fall on the floor on thebuttered side. BBC Television gathered 300 people to throwpieces of buttered toast up in the air and observe on which sidethey fell. Half fell on the buttered side, and half didn't.Now here's a tricky question for Mathews. It's known fact that cats always fall on their four legs. What happens if you tie a piece of buttered toast on a cat's back and drop them from a balcony? Will the cat land onall fours, or will the toast land on the buttered side? I sincerely hope the BBC doesn't try this experiment.Just remember that you cannot blame Murphy's Law for everything that goes wrong. If the hot water runs out while you're having a shower, it's probably because the hot water heater needs to be fixed. If your car breaks down on the way to a job interview, it's probably because you didn't have the vehicle serviced or repaired. And if you lose all your files on the computer, it's not bad luck-it's your fault for not doing a backup of your files.