DIU Activities > Alumni
Sharpen Your General Knowledge
Shamim Ansary:
Are Mountains Still Growing or Do They Shrink Eventually?
For ages, people believed that Earth would always be the same. Now we realize that it is constantly changing.
The mighty Himalaya Mountains in South Asia, with their record-breaking heights, are still growing. The great Alps in Europe may grow taller still.
On the other hand, the Rocky Mountains in the United States are continuing to wear away, just as the eastern Appalachians have diminished over time.
These changes, however, generally take place at the rate of a pebble, a rock, or a boulder at a time.
Shamim Ansary:
What Was the Reaction to Gregor Mendel’s Discovery In Genetics When His Paper Was Published In 1866?
Gregor Mendel knew he had made a great scientific discovery.
He wrote a paper on his findings in plant genetics and presented it to the Brunn Natural History Society.
They either didn’t know what he was talking about or didn’t understand the significance of it.
The paper, Experiments with Plant Hybrids, was also published in the society’s small scientific magazine, but again there was no reaction.
Mendel sent the paper to scientists throughout Europe, but they were not interested in the work of an amateur and a monk.
Mendel was appointed abbot of the monastery soon after that and spent the remaining 15 years of his life running the establishment. His new responsibilities and the disappointing reaction to his work meant there would be no more research.
When he died, his laws of heredity were still unknown.
It was not until 1900 that three scientists working on heredity discovered Mendel’s paper and revealed his findings to the world.
In the early 1900s, Swedish scientist Nilsson Ehle used Mendel’s findings to create a strain of wheat that would easily grow in Sweden’s cold climate.
Shamim Ansary:
Why Don’t All Months Have the Same Number of Days?
Our calendar comes from the ancient Romans, and is based on the sun. But before the Romans began to use their solar calendar, they used a lunar calendar, based on the moon.
A real month is the time it takes the moon to go around the earth, about 29.5 days. So the Romans gave their months 29 or 30 days. But their 12 months added up to only 354 days, so they had to add a short month of 11 days to the year from time to time.
During Julius Caesar’s reign, the Romans began to use a solar calendar instead of a lunar calendar. The Romans took the extra 11 days in the solar year and divided them up among the other months, making the first, third, fifth, seventh, ninth, and eleventh months each 31 days long. Then they took a day away from February, so that the 12 months contained exactly 365 days.
Some historians think that Augustus Caesar took a day from September and added it to August, the month named after Augustus, and also moved a day from November to December.
That’s why August and December now have 31 days, and September and November have 30. But there’s no proof that this is the way it really happened.
Shamim Ansary:
When Did the World Lose Ten Days?
In 46 B.C., Roman ruler Julius Caesar put a new calendar into effect, which came to be known as the Julian Calendar. The Romans thought that the year was 365.5 days long, so they made an ordinary year 365 days and added an extra day every fourth year, or leap year.
But by the year 730 A.D., it was known that the year was actually 11 minutes shorter than the Romans of Julius Caesar’s time thought it was. This mistake made the calendar wrong by 11 minutes each year, or one day wrong in every 128 years. By 1582, the calendar was ten days out of line with the seasons.
So in that year, Pope Gregory XIII ordered a new calendar placed into effect, which we now call the Gregorian Calendar. To keep the calendar in line with the seasons, it was decided that the first year of each century would be a leap year only when that year could be divided by 400. Therefore, 1200 and 1600 were leap years, but 1800 and 1900 were not. This change eliminated the 11-minute-per-year error in the calendar.
To bring the calendar immediately back into line with the seasons, Gregory ordered that ten days be dropped from the year 1582. People who went to bed on the night of Oct. 5 of that year woke up on Oct.15!
Some branches of the Eastern or Orthodox churches still figure their holidays according to the Julian Calendar, which is now 13 days different from ours!
Shamim Ansary:
How Does the Dimension of an Antenna Play a Significant Role In the Reception of an Electromagnetic Wave?
The length of an antenna determines the frequency that it best receives. The most efficient antennas have a length equal to half the wavelength of the wave it is receiving. This allows the induced electrical current in the receiving antenna to resonate at that particular frequency. If the antenna is a simple rod it is most sensitive when its length is one quarter the wavelength.
A loop or coil antenna are used for the low-frequency, long-wavelength signals in the AM band. A half-wavelength straight wire antenna would be over one hundred of meters long. Shorter wires or rods can be used and are more efficient if coils of wire are used to “load†the antenna.
Home FM radio and television antennas are designed to receive a broad range of frequencies, but with less sensitivity. Antennas for the ultra-high frequencies used in digital high definition televisions are very short and can be easily mounted outside on rooftops or on top of television sets.
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