Enjoyable questions and problems

  Nellie Bly. Photo Credit: Wikipedia Girls are as smart as boys. They may be smarter in some ways, like understanding people and in helping them. They may not be as good in fighting. In the old days, men controlled the world through hand-to-hand fighting and fighting with sticks and swords. However, times have changed. Women can now do most of the work men can. However, many countries do not allow girls to go to college or even high school. They do not allow women to work in offices. Such prejudice against women was there even in countries which are advanced countries now. Take the United States for example. A hundred and thirty-five years ago, a newspaper named the Pittsburgh Despatch carried an article with the title “What are girls good for?” It said that girls are good mainly for giving birth to children and for keeping house. A girl named Elizabeth, who was 21 years old at that time, did not agree with the article. She wrote a letter to the Editor of the paper arguing that ...

  PHOTO CREDIT: WIKIPEDIA    We had sweets to eat! You may wonder how the new year starts on April 14. Well! This is in Bengaluru and in Chennai, India. People of Tamil origin all over the world follow this practice. Several other states of India observe this day under different names. People from Kerala, the Punjab and Bengal are among those who celebrate New Year’s Day in April. This day used to be the day of the Spring Equinox when the Sun moves from the southern part of the sky to the northern part. For people living in the northern half of the world, this used to mark the beginning of Spring – warmer days and longer hours with sunlight. The Equinox occurs earlier nowadays. In 2023, it was on March 21. However, people stick to the practice of observing April 14 as the new year day. Srinivasan Ramani    

Photo credit: NASA and JPL. Image from Wikimedia Commons.  This image is licensed under the  Creative Commons   Attribution-Share Alike 3.0 Unported  license.  Some of the readers of this blog have been telling me that it is difficult to see Mercury. In Bengaluru, the Sun will rise at about 6:40 AM tomorrow. I have set the alarm to wake me up to see mercury at 6 AM. But it is not always easy for me to get up that early! I have found a good solution to the problem. Tomorrow, the Sun will set in the West, at about 6:30 PM, in Bengaluru. After seven PM, I will be able to see two bright planets in the west. I saw them today. The brighter one is Venus, and it will be lower in the sky than the other. The other one will be Jupiter. I am excited about these planets. More than four hundred years ago, in the year 1610, the Astronomer Galileo started observing these two planets with a home-made telescope. He saw that all of Venus was not uniformly lit. It has phases,...

  Image Credit: http://solarsystem.nasa.gov/planets/index.cfm . This is a montage of planetary images taken by spacecraft managed by the Jet Propulsion Laboratory in Pasadena, CA. Included are (from top to bottom) images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus and Neptune. Ask people you meet if they have seen the planet Mercury.  Most will say they have not seen it.  If they say they have seen it, ask them when they saw it and where.  Why is it so difficult to see? It is a planet close to the Sun. During part of the year, you see it rise on the eastern horizon. On some of these days you can see it about 45 minutes before sunrise. During another part of the year, it can be seen within 45 minutes of Sunset on Western horizon. You cannot see Mercury when the Sun is shining. The sunlight is much more powerful than the light from Mercury. It is dangerous to look at the Sun directly, because its rays can damage your eyes. Today, when I w...

  Cropped by Ramani. This file is licensed under the  Creative Commons   Attribution 3.0 Unported  license. Attribution:  Adeeb Atwan A fast motorbike went down our street one morning, making a big noise. Ten minutes later, my mom dropped her coffee mug. Can you say that the cause of mom dropping the coffee cup was the motorbike’s noise? Or was it a case of mere coincidence? This type of question was known long ago. An old Indian proverb talks about a crow and a palm tree. The crow came and sat on a palm tree and soon the tree fell down. Can we say that the crow’s sitting was the cause of the tree falling?    Or was it a case of mere coincidence? Srinivasan Ramani  

You know that drones are usually planes that fly without any pilots! They are controlled by a computer they carry.  Image Credit: NASA I think that very soon some drone will fly non-stop all around the equator, starting at some point on it and coming back to that point.  Suppose the drone flies at 100 miles per hour. How long will it take to fly a complete trip, flying over the equator?  You will have to know the distance involved. That depends on the size of the earth. Can you find out what is the distance the drone will have to fly? Then you can calculate how many hours it will take for the drone to fly this trip! Finally, you can convert the hours to days.  Talk to people who can help you with this calculation. Or perhaps, you can look up a book to find the distance involved. Ask the librarian in your school to show you an atlas. It will probably give you the answer. The librarian may help you find it.  Srinivasan Ramani 

  K452b Artist Impression Image Credit NASA and Wikimedia Commons Exoplanets are Planets outside our solar system. Over four thousand of them have been discovered. They orbit some star other than the Sun. Some are earth-like. They have temperatures suitable for living things. Some exoplanets even have an atmosphere. Some have hard surface at least in part so that life can live on it. Some other exoplanets are balls of gas! Scientists have not found any proof of living things on any of these exoplanets. Who knows, they may find proof of that in the coming years. The image above is not a photograph. It was an artist’s painting. NASA used it to tell news reporters in July 2015 about how its scientists found it. We don’t know much about it yet. It may be earth-like in some respects. It is in the constellation of Cygnus, the Swan.  Do you want to go there? Even if you travel at the speed of light, it will take approximately 1,800 years! We have no clue how we can travel that ...