The Student and The Barometer

Some time ago I received a call from a colleague. He was about to give a student a zero for his answer to a physics question, while the student claimed a perfect score. The instructor and the student agreed to an impartial arbiter, and I was selected.

I read the examination question: "Show how it is possible to determine the height of a tall building with the aid of a barometer." The student had answered: "Take the barometer to the top of the building, attach a long rope to it, lower it to the street, and then bring it up, measuring the length of the rope. The length of the rope is the height of the building."

The student really had a strong case for full credit since he had really answered the question completely and correctly! On the other hand, if full credit were given, it could well contribute to a high grade in his physics course and certify competence in physics, but the answer did not confirm this.

I suggested that the student have another try. I gave the student six minutes to answer the question with the warning that the answer should show some knowledge of physics. At the end of five minutes, he hadn't written anything. I asked if he wished to give up, but he said he had many answers to this problem; he was just thinking of the best one. I excused myself for interrupting him and asked him to please go on.

In the next minute, he dashed off his answer, which read: "Take the barometer to the top of the building and lean over the edge of the roof. Drop the barometer, timing its fall with a stopwatch. Then, using the formula x=0.5*a*t^2, calculate the height of the building." At this point, I asked my colleague if he would give up. He conceded, and gave the student almost full credit.

While leaving my colleague's office, I recalled that the student had said that he had other answers to the problem, so I asked him what they were. "Well," said the student, "there are many ways of getting the height of a tall building with the aid of a barometer. For example,if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the skyscraper's shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the skyscraper.

"Fine," I said, "and others?"

"Yes," said the student, "there is a very basic measurement method you will like. In this method, you take the barometer and begin to walk up the stairs. As you climb the stairs, you mark off the length of the barometer along the wall. You then count the number of marks, and this will give you the height of the building in barometer units." "A very direct method."

"Of course. If you want a more sophisticated method, you can tie the barometer to the end of a string, swing it as a pendulum, and determine the value of g [gravity] at the street level and at the top of the building. From the difference between the two values of g, the height of the building, in principle, can be calculated."

"On this same tack, you could take the barometer to the top of the building, attach a long rope to it, lower it to just above the street, and then swing it as a pendulum. You could then calculate the height of the building by the period of the precession".

"Finally," he concluded, "there are many other ways of solving the problem. Probably the best," he said, "is to take the barometer to the basement and knock on the superintendent's door. When the superintendent answers, you speak to him as follows: 'Mr. Superintendent, here is a fine barometer. If you will tell me the height of the building, I will give you this barometer."

At this point, I asked the student if he really did not know the conventional answer to this question. He admitted that he did, but said that he was fed up with high school and college instructors trying to teach him how to think.

The name of the student was Niels Bohr, who later received the Nobel prize for Physics.

100 Reasons To Party
. Because it's Friday.

2. Because your dentist canceled your appointment.

3. Because you can't think of anything boring to do.

4. Because it's daytime.

5. Because it's nighttime.

6. Because it's exactly one week later than it was this time last week.

7. Because you like to make ice.

8. Because you want to annoy your neighbors.

9. Because you're dying to wear your new light shade.

10. Because you're tired of playing 'Charades' with yourself.

11. Because you're carrying a party gene.

12. Because you found the perfect shoes.

13. Because you're afraid your lifestyle is too healthy.

14. Because you never know...

15. Because your place could use a good mess.

16. Because your mother needs something to be upset about.

17. Because you have a sudden urge to limbo.

18. Because your inhibitions are out of town.

19. Because the bank made an error in your favor.

20. Because it's there.

21. Because you need more bean dip in your diet.

22. Because the fun content of your blood is too low.

23. Because you look good doing it.

24. Because you're considering it as a career.

25. Because your yo-yo stock went up a point.

26. Because someone's got to do it.

27. Because you have a bad reputation to uphold.

28. Because your plants want to meet new people.

29. Because fun is a terrible thing to waste.

30. Because you want to try out your new jokes.

31. Because it's your patriotic duty.

32. Because you're going for the party record.

33. Because your roommate got rid of his scorpion farm.

34. Because you need the practice.

35. Because you're not getting any younger.

36. Because the vet says your hamster will pull through.

37. Because you've got it coming to you.

38. Because your life is starting to grow moss.

39. Because your brain needs a night off.

40. Because you never met a party you didn't like.

41. Because the fate of the free world depends on it.

42. Because the universe is expanding.

43. Because your dog is finally housebroken.

44. Because it's the only exercise you get.

45. Because maturity is overrated.

46. Because a party demon has possessed your body.

47. Because it hurts too much when you stop.

48. Because these are your "party years!"

49. Because you're too polite to turn down an invitation.

50. Because you can't boogie to a book.

51. Because you have an overactive party gland.

52. Because the moon is in a party phase.

53. Because otherwise the police would have nothing to do.

54. Because curfew has been lifted.

55. Because the phone company lost your Internet bill.

56. Because you won the lottery and feel reckless.

57. Because life seems so dull without it.

58. Because that's how the dinosaurs would have wanted to go.

59. Because you haven't eaten a million corn chips yet.

60. Because you're suffering from popcorn deficiency.

61. Because you're supposed to be the irresponsible one.

62. Because how else are you going to learn to juggle chainsaws?

63. Because your bank manager finally lifted that death threat.

64. Because you need to get to know more riot police.

65. Because your budgie ate your concert tickets and you need to let the party feeling out somehow.

66. Because the voices tell you to.

67. Because if not you, who else?

68. Because it's time.

69. Because the local committee like you too much.

70. Because you need to cultivate a bad impression.

71. Because if you don't you'll explode.

72. Because you got your coursework in on time.

73. Because your lecturer forgot to set work for the weekend.

74. Because you suspect you're too uptight.

75. Because you need to get ready for New Year's.

76. Because THEY don't want you to.

77. Because it's a long way till midnight, and you've got ten crates to get through.

78. Because you want to finish all the food in your house before dawn.

79. Because someone bet you to.

80. Because the dice tell you to.

81. Because you haven't heard a police megaphone for a whole week.

82. Because you want to meet new alcohol.

83. Because that's the last thing they'll expect.

84. Because it's down to you.

85. Because you spend too much time on the Net and you don't want to develop keyboard withdrawal.

87. Because how else are you going to rebel?

88. Because you just want to, alright, ALRIGHT?!

89. Because you're too tense.

90. Because everyone you know needs convincing you're insane.

91. Because your parrot accused you of being boring.

92. Because you know at least "30 things to do before you're 30" that you haven't done.

93. Because you need good reference material.

94. Because you want to create a false identity.

95. Because you want to prove you can.

96. Because you feel like everyone's ignoring you.

97. Because you want to improve your crime sheet.

98. Because you have a very evil punch recipe.

99. Because because because because... because of the wonderful things it does! (see Wizard of Oz)

100. Because you need to work on your purity test score.