After the 22nd July 2009 eclipse, I was invited for an online chat on the Network 18 owned website, IBN Live. They invited the viewers to submit questions which were put forward to me after a first level moderation. I was quite impressed by the quality of questions asked. The chat was supposed to go on for an hour but I was really enjoying myself so it went on for almost two hours. I have attached the transcript below. If you want to check the original transcript you can find it here. The questions are in reverse order, the first being right at the bottom.
Milinda:Just reading your experience of solar eclipse excites me here (reading this chat from office) in Pune & we are covered with think clouds and rains. The answer on – what was your immediate reaction – really gave me a experience of the occasion … that’s for writing back to us
Nikhil Pawar: Milinda, it was an experience of a lifetime. As I have written earlier the clouds did hamper us a bit but even then the experience was simply phenomenal. I realized that to see the entire sky go dark at 6:30 in the morning is something that you cannot prepare yourself for. As drenched as all of us were we were jumping and shouting with joy when the moon’s shadow fell on us. Just imagine standing under the shadow of the Moon. That alone is a incredible feeling. I am having withdrawal symptoms right now 🙂
Smiti:Sir,how long does the total phase of Solar eclipse last??? And what is Camera Obscura? Why is it harmful to see the eclipse with naked eye?
Nikhil Pawar: The total phase or totality may last anywhere between a few seconds to a few minutes. Depends of the position of The Earth and the Moon in their respective orbits. Camera Obscura is a pinhole projection technique that may be employed to view an eclipse safely. Simply take a sheet of paper, punch a small hole in it and let sunlight pass through it on to the ground. You will see an image of the Sun. You can check that it is actually the Sun’s image by cutting out triangular hole of square hole. You will always get a circular image on the ground. Thats because you are seeing an image of the Sun which appears circular. Make sure that the sheet is a little distance away from the ground. An eclipse is harmful to view directly because the Sun is emitting infra red rays and UV rays in addition to visible light. (at all times not just during an eclipse). These rays can harm the human eye. And you wont even know that your eye is getting hurt as it has no cells sensitive to pain!
anusha:to join in ur organization(SPACE), should we write any entrance xams?? can u tell us the various courses u offer n its duration??
Nikhil Pawar: SPACE is an organization dedicated to spread awareness about science. SPACE actually stands for (Science Popularisation Association of Communicators and Educators) We are a group of scientists and astronomers and educators who take astronomy and science to the masses. Check up more on one of our sister websites http://www.stepl.org
Ashwin Gangakhedkar:Hello Nikhil, I am reading your chat and it is indeed very informative and knowledge enriching. Being in Pune we missed out on the eclipse. But what effect does the eclipse have on earth’s gravitational force? Some predict abnormal behaviour of sea or even earthquakes. To what extent do these statements hold good?
Nikhil Pawar: Ashwin there are no known ill effects on the Earth during eclipses. remember it is just a normal New Moon day (amavasya). It just happens of occur right in front of the Sun. So gravitationally speaking it is not very different from any other new moon. Al these earthquake predictions are not credible. None of the recognized geologist groups have made such claims.
priyanka muralidharan:Is it true that lunar eclipses generally tend to last longer than solar eclipses….especially the moments of totality…any particular reason why that happens if it is true?
Nikhil Pawar: Yes. Lunar “totality” tends to last longer as the Earth is bigger than the moon and hence casts a bigger shadow. The Moon stays in this shadow for a longer time.
anoop kashyap:What does it mean by ‘the only Total Solar Eclipse of the century’? Does it mean there will be No Solar Eclipse for the whole world until 2132 or only for Asia ?? If so , Why ??
Nikhil Pawar: This is the longest eclipse of the century. Not the only eclipse. Total solar eclipses happen almost every year. This one is special because it is the longest eclipse of the century.
Milinda:We are enjoying the solar eclipse from earth ,is there someone (group) enjoying it from space / air?
Nikhil Pawar: Oh yes! For the first time in India the organization SPACE in association with Cox & Kings arranged an Eclipse Flight. We charterd a JetLite aircraft that took off from Delhi earlier today, intercepted the Moon’s shadow 41000 ft above Taregana near Patna. All the passengers got the best possible view of the eclipse. This concept of Astronomy Tourism has been brought to India by Mr Sachin Bahmba.
suni_D:is it safe to watch complete solar eclipse with naked eyes?
Nikhil Pawar: Only when the Moon completely covers the Sun, ie during totality, when not a single ray of sunlight is coming towards us is it safe to watch the eclipse with naked eyes. This happens only for a few minutes. Even if the eclipse is 99% partial one must view it with certifies solar goggles. So in a total eclipse like the one we got today, you must have solar goggles at all times (almost two hours) except for the 4 minutes of totality. The sunrays are very strong and can burn the retina if viewed directly.
Mrudula:why do eclipses last only for a few seconds or minutes normally?
Nikhil Pawar: The apparent (not actual) size of the Sun and Moon in the sky is roughly the same (half degree angular diameter). Due to this eclipses last only for a few minutes. If the moon would appear much bigger then the totality would be longer.
INDULEKHA PAWAR:THE SCIENTIFIC OFFICERS LIKE U AND YOUR COLLEAGUES MUST BE EXITED RIGHT NOW.WHAT IS YOUR EXPERIENCE
Nikhil Pawar: All the teams are excited. Though clouds blocked out some of the best features of an eclipse the experience was exhilarating. We experienced a day of to sunrises 🙂 Students were screaming with excitement and jumping with joy just when we came under the shadow of the Moon. We were all drenched with rain but it just could not dampen our spirits.
Pankaj Giri:Is there any part time course available for amateur individuals to know more about Space.
Nikhil Pawar: There are amateur astronomy clubs in most cities of India. My organization SPACE is placed in Delhi, Hyderabad, Bangalore and Kolkata. You can join any of these clubs and learn more about astronomy and space sciences. Also check up our yahoo group called Astronomicans. Anyone interested can join it.
arun:Hi i have two questions for you. 1) will Solar eclipse cause any harm to planet earth in the from natural disaster and will it create negative energy in the psychological mind? 2) If not they why the astrologer and other people are spreading the wrong message and why scientist like you and ISRO not taking any action against this.
Nikhil Pawar: Arun there is absolutely nothing evil or negative about eclipses. astrologers earn a lot by scaring people. Time and time again scientists have battled against astrologers but it is up to people to adopt a scientific mind set and get rid of this superstitions. Till the people listen, the astrologers will spread misinformation.
Smiti:What is the effect of solar eclipse on Animals ???
Nikhil Pawar: Bird and animal behavior has been tracked for quite a while now. Birds especially tend to get confused when totality hits. Animals also sense something off and get restless and anxious. As more and more data comes in we will learn more about how they react.
anusha:since satellites have to work on batteries during solar ecclipse, how is this longest solar eclipse going to effect the satellites?
Nikhil Pawar: satellites are used to stay for long hours in the absence of sunlight. Remember that satellites survive through the night as well. So a few minutes of Moon shadow does not affect them at all.
Preeti Pardeshi:Since you were in Patna I’m hoping you saw the eclipse in totality! Please fill us in on how it felt to watch this awesome phenomenon! 🙂
Nikhil Pawar: There were clouds from about 4:30 am in Patna. so the view of the Sun was blocked. In fact it even started raining and all of us got drenched while trying to protect our equipment. The Sun was supposed to be covered completely by the Moon at 6:24 am. That was the start of totality as it is called. The rain stopped about 4 minutes before this time. We started a ten second countdown in anticipation of totality not knowing what to expect. The second we hit 3…2…1…0… the sky suddenly turned dark as night. we were surprised by the level of light intensity drop. It stayed as dark as night for about 3.5 minutes and exactly at the predicted moment, totality ended and the light returned just as suddenly as it had disappeared. We couldn’t see the Sun but this entire darkening was simply phenomenal. Ironically the sky cleared a bit after totality giving us a few glimpses at the partially eclipsed crescent Sun.
Milind Pawar:Hi Nikhil, keeping in mind that sun goes out for few minutes, however – does the moon gravity creates any prism kind of effect on the sun rays – @ which we are yet to be fully aware – which can cause changes in atmosphere –
Nikhil Pawar: Einstein’s General theory of relativity does predict bending of light by massive objects but more than the Moon it is the Sun that exhibits this. Very precise observations show that the Sun creates a gravitational lens and bends light coming from background star by a very small amount. The Moon is too small to create this gravitational lens that can be observed.
priyanka muralidharan:You did say that you’ll had quite a few experiments planned during the eclipse, but the rain played spoil sport.Can you tell us which experiments can be conducted during an eclipse and especially small experiments which can probably be performed at home by school children?
Nikhil Pawar: We planned to track changes in air temperature, soil temperature, wind speed, humidity and light intensity. All these are quite simple to perform. The equipment needed is readily available and the data that you collect is very significant to understand how the atmosphere reacts to the umbral shadow (shadow of the Moon. we had planned these experiments at Patna and china (the two places where we sponsored students to go on a scientific expedition)
Joyeeta:As this solar eclipse is the longest one, can you explain its importance? Astrology prediction shows many advantages and disadvantages. Do you believe in astrology predictions?
Nikhil Pawar: All astrologers do is spread panic and misinformation. They have no proof for any of their claims and no scientific basis. I do not believe in astrology and anyone who holds reason and rationality as their highest virtues will see the hoax of astrologers. Please do not believe a single word they say. there is nothing evil about eclipses.
ashokpawar:How to educate masses on superstitions about eclipse?
Nikhil Pawar: The best way is to educate students. And education does not just mean “telling” them to view an eclipse. They must be given reasons and they must be made to understand the phenomenon of eclipses. Once they understand the science behind it, they will throw away the superstitions themselves. Women must also take the initiative to learn more about this phenomenon. They hold a lot of power to educate their families. Public and pvt organisations must organize mass events. It will create publicity for them as well as spread awareness in society.
Preeti Pardeshi:Hi Nikhil, Im guessing this is what you’ve wanted to do ever since you were a child! What advice to you have for budding astronomers?
Nikhil Pawar: Even a clouded out eclipse was worth all the effort the entire team of astronomers from SPACE took for the past few months. It was an exhilarating feeling. All young students should concentrate on pure sciences, not get distracted by all the baseless rumors spread out by some sections of society and look forward to experiencing all aspects of astronomy. Go out for night observations, pick up a telescope and satisfy your curiosity. You will be amazed at how much there is to discover and enjoy in astronomy. There is a lot more to astronomy than just eclipses and starry nights. If not professionally, at least every student should pick astronomy as a hobby.
anusha:good moning Mr.nikhil pawar! during night times we see moon. when moon covered the sun during solar eclipse, why cant we see moon?
Nikhil Pawar: The Moon does not have light of its own. It reflects the the light of the Sun. This is why we see different phases of the Moon. During an eclipse, the side facing away from the Earth gets sunlight as the Sun is behind the Moon. The side facing us has no sunlight falling on it. Hence we cannot see the Moon. Incidentally all solar eclipses happen on a New Moon day and all lunar eclipses occur on a Full Moon day.
Divyesh:What is your first expression after this eclipse?
Nikhil Pawar: This was my first total solar eclipse. I had already seen an Annular Eclipse, a partial solar eclipse and lunar eclipses. So needless to say I was looking forward to it. Everyone in our organisation was preparing for it for the past few months. Unfortunately at Patna, clouds blocked the views of the diamond ring and corona of the Sun. But even then the dramatic sudden drop in light intensity amazed me. All of us just gave a collective expression of “Whoa!!” at the light intensity change. It was much more than what we had expected and very sudden.
Gopal Das:What is the average duration for a lunar and solar eclipse?
Nikhil Pawar: A total solar eclipse will typically last for 2 hours (5:30 IST to 7:30 IST for the 22nd July eclipse in India). This is from a point the Moon just touches one edge of the Sun till it crosses over and leaves the other edge. The period for which the entire Sun is covered by the Moon will tend to vary from as little as a few seconds to a maximum of 7 min and 29 sec
satanmig:It is said that a Solar eclipse occurs every 18 months on an average. Is this figure correct and if so then can a periodic calendar be drawn up to see more eclipses?
Nikhil Pawar: A solar eclipse in fact happens approximately once every 6 months. We had one in Jan, today’s was six months later. Again we have an annular solar eclipse in Jan 2010. So yes a periodic timescale exists. It helps us predict eclipses. There is another periodic cycle called the Saros Cycle. According to this cycle, the same eclipse will repeat itself in about 18 years and a few days but over some other location of the Earth. thus all eclipses have a saros number.
Gopal Das:What is the longest a total solar eclipse can last?
Nikhil Pawar: Remember the orbit of the Earth and the Moon is elliptical. If the Moon is closest in its orbit around the Earth and the Earth is farthest in its orbit around the Sun, we will get the longest eclipse. The maximum duration can be 7 min and 29 sec. An eclipse of this duration is predicted on July 16, 2186.
Kuntal:Where will the next total solar eclipse occur?
Nikhil Pawar: The next total solar eclipse will be on Sunday, 2010 July 11. It will be visible from within a narrow corridor that traverses Earth’s southern Hemisphere. The path of the Moon’s umbral shadow crosses the South Pacific Ocean. It does not hit any landmass except for Mangaia (Cook Islands) and Easter Island (Isla de Pascua). The path of totality ends just after reaching southern Chile and Argentina.
kamini:Is this event more exciting for astronomers or astrologers?
Nikhil Pawar: Interesting question. While astronomers across the world prepare for months together in anticipation of an eclipse such as this, astrologers tend to just spread fear by announcing all the evils that an eclipse will cause. There is no scientific basis to their claims and they have no proof either. So they probably just try to cash in on some publicity. They have little to do with the actual event. The event itself is a big moment for astronomers. I spent a sleepless night last night in anticipation of this eclipse. My entire team was as excited as I was. The solar corona, diamond’s ring and all the other phenomena are just too tempting
Preetam:What scientific discoveries are expected from the eclipse?
Nikhil Pawar: Long time ago Einstein’s General Theory of relativity was proved during a solar eclipse by looking at the slight change in the position of stars near the Sun due to light bending. This is a phenomenon that Einstein’s theory predicted. Helium was also discovered during a solar eclipse. These days the solar corona is studied extensively during eclipses. The Moon’s limb can also be studied in detail during an eclipse. weather changes are also studied and tracked during eclipses
suni_D:Do you think that this solar eclipse will have severe effect on whether for few days?
Nikhil Pawar: Hi Suni. Solar Eclipses do not have any known long term effect on the weather as the sun only goes out for few minutes, while during the night it remains missing for a few hours. Earths atmosphere however does go into a kind of a shock because of cutting of the sun light quite quickly. For example, in our eclipse journeys we have measured temperature drops of about 7 degrees, change in wind speeds etc.
Nikhil Pawar
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The Astronomy Journal 
Posted on July 25, 2009
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