Edward A. Murphy, Jr. was one of the engineers on the rocket-sled experiments that were done by the U.S. Air Force in 1949 to test human acceleration tolerances (USAF project MX981). One experiment involved a set of 16 accelerometers mounted to different parts of the subject's body. There were two ways each sensor could be glued to its mount, and somebody methodically installed all 16 the wrong way around. Murphy then made the original form of his pronouncement, which the test subject (Major John Paul Stapp) quoted at a news conference a few days later.
Within months `Murphy's Law' had spread to various technical cultures connected to aerospace engineering. Before too many years had gone by variants had passed into the popular imagination, changing as they went. Most of these are variants on "Anything that can go wrong, will"; this is correctly referred to as Finagle's Law. The memetic drift apparent in these mutants clearly demonstrates Murphy's Law acting on itself!
You don't make a two-pin plug symmetrical and then label it `THIS WAY UP'; if it matters which way it is plugged in, then you make the design asymmetrical.
If you take the phone with you outside, say to garden, it will never ring, but if you leave it inside there will be several messages on your voicemail.
2. All Warranties will expire upon payment of invoice
4. Friends come and Go, but enemies accumulate
12. If you try and please everybody noone will like it
14. You will always find something in the last place you look
15. The chance of a piece of bread falling with the buttered side down is directly proportional to the cost of the carpet
20. Anything you try to fix will take longer and cost more than you thought
21. If you fool around with a thing for very long, you will screw it up
22. A $300.00 picture tube will protect a 10c fuse by blowing first
24. Any tool dropped while repairing a car will roll underneath to the exact centre
25. The repairman would have never seen a model quite like yours before
26. When a broken appliance is demonstrated fot the repairman, it will work perfectly
30. Everybody has a scheme for getting rich that will not work
35. You will remember that you forgot to take out the garbage when the garbage truck is 2 doors away
37. Theres never a time to do it right, but thers always time to do it over
39. Anything good in life is either illegal, immoral or fattening
47. Never sleep with anyone crazier than yourself.
50. Never play leapfrog with a unicorn
52. If everybody seems to be going well, you obviously dont know what the hell is going on
54. In case of doubt, make it sound convincing
55. Never argue with a fool, people might not know the difference