Saturday 31 March 2018
Friday 30 March 2018
Thursday 29 March 2018
Sunday 11 March 2018
Saturday 10 March 2018
Tuesday 6 March 2018
The student was Niels Bohr, who went on to win the Nobel Prize for Physics.
A question in a Physics exam at the University of Copenhagen, Denmark several decades ago said: "Describe how to determine the height of a skyscraper with a barometer." One student replied: "You tie a long piece of string to the neck of the barometer, then lower the barometer from the roof of the skyscraper to the ground. The length of the string plus the length of the barometer will equal the height of the building."
This highly original answer so incensed the examiner that the student was failed. The student appealed on the grounds that
his answer was indisputably correct, and the university appointed an independent arbitrator to decide the case.
his answer was indisputably correct, and the university appointed an independent arbitrator to decide the case.
The arbitrator judged that the answer was indeed correct, but did not display any noticeable knowledge of physics. To resolve the problem it was decided to call the student in and allow him six minutes in which to show a minimal familiarity with the basic principles of Physics.
For five minutes the student sat in silence, forehead creased in thought. The arbiter reminded him that time was running out, to which the student replied that he had several extremely relevant answers, but couldn't make up his mind which to use.
On being advised to hurry up the student replied as follows: "Firstly, you could take the barometer up to the roof of the skyscraper, drop it over the edge, and measure the time it takes to reach the ground. The height of the building can then be worked out from the formula H = 0.5g x t squared. But bad luck on the barometer."
"Or 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."
"But if you wanted to be highly scientific about it, you could tie a short piece of string to the barometer and swing it like a pendulum, first at ground level and then on the roof of the skyscraper. The height is worked out by the difference in the gravitational restoring force T = 2 pi square root (l / g)."
"Or if the skyscraper has an outside emergency staircase, it would be easier to walk up it and mark off the height of the skyscraper in barometer lengths, then add them up."
"If you merely wanted to be boring and orthodox about it, of course, you could use the barometer to measure the air pressure on the roof of the skyscraper and on the ground, and convert the difference in millibars into feet give the height of the building."
"But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the janitor's door and say to him 'If you would like a nice new barometer, I will give you this one if you tell me the height of this skyscraper'."
Sunday 4 March 2018
Friday 2 March 2018
The Voice of the Cricket
A Great Speech from a Great Man
Pinocchio has been hanged by assassins, cut down by a falcon, and taken to the home of Fairy. The most famous doctors in all the realm have been summoned in consultation. One after another they arrive and place themselves around the bed of Pinocchio—a crow, an owl, and a talking cricket. The Fairy gives them a brief history of the case and then asks them a simple question: Is the puppet dead or alive?
Crow advances first, feels the puppet's pulse, then his nose, then the toe of his foot. Having done this carefully, he steps back and solemnly renders the following opinion, “To my belief, the puppet is already quite dead; but if unfortunately he should not be dead, then it would be a sign that he is still alive.”
Next the owl comes forward, examines the patient, steps back and says, “I regret to be obliged to contradict the crow, my illustrious friend and colleague, but in my opinion the puppet is still alive; but if unfortunately he should not be alive, then it would be a sign he is dead indeed.”
All the while, Cricket stands quietly by. He is a little fellow and except for a tall black hat, is quite ordinary in appearance. However, if one looks closely, it is evident that he is unimpressed by the performance of his fellow consultants.
“And you—have you nothing to say?” asked the Fairy.
“In my opinion,” replied Cricket, “the wisest thing a prudent doctor can do, when he doesn't know what he is talking about, is to be silent.” And with that he turned and walked away.1
Pinocchio has been hanged by assassins, cut down by a falcon, and taken to the home of Fairy. The most famous doctors in all the realm have been summoned in consultation. One after another they arrive and place themselves around the bed of Pinocchio—a crow, an owl, and a talking cricket. The Fairy gives them a brief history of the case and then asks them a simple question: Is the puppet dead or alive?
Crow advances first, feels the puppet's pulse, then his nose, then the toe of his foot. Having done this carefully, he steps back and solemnly renders the following opinion, “To my belief, the puppet is already quite dead; but if unfortunately he should not be dead, then it would be a sign that he is still alive.”
Next the owl comes forward, examines the patient, steps back and says, “I regret to be obliged to contradict the crow, my illustrious friend and colleague, but in my opinion the puppet is still alive; but if unfortunately he should not be alive, then it would be a sign he is dead indeed.”
All the while, Cricket stands quietly by. He is a little fellow and except for a tall black hat, is quite ordinary in appearance. However, if one looks closely, it is evident that he is unimpressed by the performance of his fellow consultants.
“And you—have you nothing to say?” asked the Fairy.
“In my opinion,” replied Cricket, “the wisest thing a prudent doctor can do, when he doesn't know what he is talking about, is to be silent.” And with that he turned and walked away.1
WHAT IS IMPACT FACTOR?
The impact factor
for a particular journal is calculated by taking the number of manuscripts published in the journal over the past two years, and then dividing this number by the number of citations these specific manuscripts received over the same two-year period.
H-index
This is the value at which x number of manuscripts received x number of citations, with x being used here twice to denote equivalence. Thus, an Hindex of 5 would mean that an individual has 5 publications that have been cited at least 5 times. As this number increases, this implies that the individual is amassing more publications with increasing number of citations. Thus, the H-index allows for taking into account the number of citations, as well as the number of publications in a single metric. But amassing citations for a publication, and publishing new manuscripts, takes times. The H-index, therefore, self-evidently increases with years of experience.
for a particular journal is calculated by taking the number of manuscripts published in the journal over the past two years, and then dividing this number by the number of citations these specific manuscripts received over the same two-year period.
H-index
This is the value at which x number of manuscripts received x number of citations, with x being used here twice to denote equivalence. Thus, an Hindex of 5 would mean that an individual has 5 publications that have been cited at least 5 times. As this number increases, this implies that the individual is amassing more publications with increasing number of citations. Thus, the H-index allows for taking into account the number of citations, as well as the number of publications in a single metric. But amassing citations for a publication, and publishing new manuscripts, takes times. The H-index, therefore, self-evidently increases with years of experience.
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