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.

An Internet Christmas
T'was the Internet Night Before Christmas

'Twas the night before Christmas, when all through the Net,
There were hacker's a surfing. Nerds? Yeah, you bet.
The e-mails were stacked by the modem with care,
In hopes that St. Nicholas soon would be there.


The newbies were nestled all snug by their screens,
While visions of Java danced in their dreams.
My wife on the sofa and me with a snack,
We just settled down at my rig (it's a Mac).

When out in the Web there arose such a clatter,
I jumped to the site to see what was the matter.
To a new page my Mac flew like a flash,
Then made a slight gurgle. It started to crash!!

I gasped at the thought and started to grouse,
Then turned my head sideways and clicked on my mouse.
When what to my wondering eyes should appear,
My Mac jumped to a page that wasn't quite clear.

When the image resolved, so bright and so quick,
I knew in a moment it must be St. Nick!
More rapid than mainframes, more graphics they came,
Then Nick glanced toward my screen, my Mac called them by name;

"Now Compaq! Now Acer!", my speaker did reel;
"On Apple! On Gateway!" Santa started to squeal!
"Jump onto the circuits! And into the chip!
Now speed it up! Speed it up! Make this thing hip!"

The screen gave a flicker, he was into my "Ram",
Then into my room rose a full hologram!
He was dressed in all red, from his head to his shoes,
Which were black (the white socks he really should lose).

He pulled out some discs he had stored in his backpack.
Santa looked like a dude who was rarin' to hack!
His eyes, how they twinkled! His glasses, how techno!
This ain't the same Santa that I used to know!

With a wink of his eye and a nod of his head,
Santa soon let me know I had nothing to dread.
He spoke not a word, gave my Mac a quick poke,
And accessed my C drive with only a stroke.

He defragged my hard drive, and added a "Dimm",
Then threw in some cool games, just on a whim!
He worked without noise, his fingers they flew!
He distorted some pictures with Kai's Power Goo!

He updated Office, Excel and Quicken,
Then added a screensaver with a red clucking chicken!
My eyes widened a bit, my mouth stood agape,
As he added the latest version of Netscape.

The drive gave a whirl, as if it were pleased,
St. Nick coyly smiled, the computer appeased.
Then placing his finger on the bridge of his nose,
Santa turned into nothing but ones and zeros!

He flew back into my screen and through my uplink,
Back into the net with barely a blink.
But I heard his sweet voice as he flew from my sight,
"Happy surfing to all, and to all a good byte!"