Science: From the forum

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Fun and magical science experiments in school

Praveen Kamath K, GHS Ankanahally, Somavarpet TQ, Kodagu
"DEAR STF,
Here by I am attaching odt file of simple and magical 28 science experiments which my students did on 28th february on science day.In these experiments some are taken from 8th,,9th standard text book and some are outside the text book. Please go through it and add some more experiments to it so that we can create a laboratory manual for our students. Thanking you.

The file will be uploaded shortly.

Answer these questions

Shailaja.H.L. Yelwala, Mysore Taluk and district

  1. What was the need for vertebrates to evolve from oviparity to viviparity?
  2. A person stammers, which part of the brain is affected?
  3. A diabetic patient who is losing weight drastically may feel more chill than a non diabetic person. Why?

Sanjeevkumar Isaraddi, Bilagi Taluk, Bagalkote district

  1. Because parental care and nourishment to their young ones is the course of evolution. This resulted in evolution favouring viviparity (live young ones are born)
  2. When a person stammers, cerebrum is the affected part of the brain.
  3. A diabetic patient who is losing weight drastically may feel more chill than a non diabetic person. Because diabetic patient loses the fat and you know that fat act as thermoregulant in our body

Can scientists follow religious festivals

Tharanath Achar, Teacher, Belthangady ಶುಕ್ರವಾರ ವರಮಹಾಲಕ್ಷ್ಮಿ ಪೂಜೆ. ಶ್ರಾವಣ ಶುಕ್ರವಾರದಂದು ಮಹಾಲಕ್ಷ್ಮಿಯನ್ನು ಮನೆ ತುಂಬಿಕೊಂಡರೆ ಮನತುಂಬುವಷ್ಟು ಧನ ಧಾನ್ಯ , ಸುಖ ಸಂತೋಷ ಕರುಣಿಸುವಳು ಎಂಬ ನಂಬಿಕೆ. ಈ ದಿನ ಹೂವಿನ ಅಲಂಕಾರದಿಂದ ದೇವಿ ಮೈದುಂಬಿರುತ್ತಾಳೆ. ಒಡವೆಗಳ ಮಧ್ಯೆ ರಾರಾಜಿಸುವ ಲಕ್ಷ್ಮಿಗೆ ವಿವಿಧ ನೈವೇದ್ಯದ ಅರ್ಪಣೆ. ಮನೆಯಲ್ಲಿ ಸಿಹಿ ತಿಂಡಿ, ಹಬ್ಬದೂಟದ ಸಡಗರ. ಪೂಜೆ ಪುನಸ್ಕಾರಗಳ ವೈಭವ.

ಹೆಣ್ಣು ಮಕ್ಕಳು ಲಕ್ಷ್ಮಿ ಪೂಜೆ ಮಾಡಿದರೆ ಒಳಿತು ಎಂಬುದು ವಾಡಿಕೆ. ಆದ್ದರಿಂದ ದೇವಿ ಪೂಜೆ ಮಾಡಲು ಹೇಗೆ ತಯಾರಿ ಮಾಡಿಕೊಳ್ಳಬಹುದು ಎಂಬ ಬಗ್ಗೆ ಕೆಲವು ಮಾಹಿತಿಗಳು ಇಲ್ಲಿವೆ. ಪೂಜಾ ಕೋಣೆಯನ್ನು ಒಪ್ಪವಾಗಿ ಅಲಂಕರಿಸಿ ದೇವಿಯನ್ನು ಬರಮಾಡಿಕೊಂಡರೆ ಒಲಿದು ಬರುವಳು.

1. ನಾಣ್ಯಗಳ ಜೋಡಣೆ: ಸರ್ವಸಂಪತ್ತಿನ ದೇವಿಯಾಗಿರುವ ಲಕ್ಷ್ಮಿಯನ್ನು ಬರಮಾಡಿಕೊಳ್ಳಲು ನಾಣ್ಯಗಳಿಂದ ರಂಗೋಲಿ ಚಿತ್ತಾರ ಜೋಡಣೆ ಮಾಡಬಹುದು. ನೆಲದ ಮೇಲೆ 1,2,5 ರೂಪಾಯಿಯ ನಾಣ್ಯಗಳನ್ನು ರಂಗೋಲಿಯಂತೆ ಜೋಡಿಸಬಹುದು. ಇತ್ತೀಚೆಗೆ 5 ರೂ ನಾಣ್ಯ ಚಿನ್ನದ ಬಣ್ಣದಲ್ಲಿ ಇರುವುದರಿಂದ ಇದನ್ನು ಜೋಡಿಸಿದರೆ ಚಿನ್ನದ ನಾಣ್ಯದಲ್ಲೇ ಅಲಂಕಾರ ಮಾಡಿದಂತೆ ಕಾಣುತ್ತದೆ. ಮಂಟಪವಿದ್ದರೆ ಅದರಲ್ಲಿ ಈ ನಾಣ್ಯ ಜೋಡಿಸಿದರೆ ಪೂಜಾ ಕೋಣೆ ಮಿನುಗುತ್ತದೆ.

2. ನೋಟಿನ ಅಲಂಕಾರ: 10,20,50 ರೂಗಳ ನೋಟನ್ನು ಪೂಜಾ ಕೋಣೆಯಲ್ಲಿ ದೇವಿಯ ಮುಂದೆ ತಟ್ಟೆಯಲ್ಲಿ ವೃತ್ತಾಕಾರವಾಗಿ ಅಥವಾ ಲಕ್ಷ್ಮಿ ಕಲಶವಿಡುವ ತಟ್ಟೆಯಲ್ಲಿ ಸುತ್ತಲೂ ನೋಟುಗಳನ್ನು ಒಂದರ ಮೇಲೊಂದಂತೆ ಜೋಡಿಸಿದರೆ ನೋಡಲು ಆಕರ್ಷಕವಾಗಿರುತ್ತದೆ. ನೋಟುಗಳನ್ನು ತೋರಣದಂತೆಯೂ ಕಟ್ಟಬಹುದು. ಆದರೆ ಪಿನ್ ಹೊಡೆಯುವಾಗಾ ಜೋಪಾನದಿಂದಿರಬೇಕು. ನೋಟಿನ ಹಾರವನ್ನೂ ಫೋಟೊಗೆ ಹಾಕಬಹುದು.

3. ಕಮಲದ ಹೂವಿನ ಜೋಡಣೆ: ಲಕ್ಷ್ಮಿ ಕಮಲಪ್ರಿಯೆ. ಆದ್ದರಿಂದ ಮಂಟಪದ ಎದುರು ಅಥವಾ ಕಲಶದ ಎರಡೂ ಬದಿಯಲ್ಲಿ ಹೂಕುಂಡದಲ್ಲಿ ನೀರು ತುಂಬಿಸಿ ಕಮಲದ ಹೂವನ್ನು ನಿಲ್ಲಿಸಬಹುದು. ಕಮಲದ ಎಲೆಗಳನ್ನು ದೀಪದ ಸುತ್ತಲೂ ಎಳೆಎಳೆಯಾಗಿ ಜೋಡಿಸಿದರೆ ದೀಪ ಇನ್ನಷ್ಟು ಮಿನುಗುವಂತೆ ಚೆನ್ನಾಗಿ ಕಾಣುತ್ತದೆ.

4. ಅಷ್ಟ ಲಕ್ಷ್ಮಿ: ಆದಿ ಲಕ್ಷ್ಮಿ, ಧನ ಲಕ್ಷ್ಮಿ, ಧೈರ್ಯ ಲಕ್ಷ್ಮಿ, ವಿದ್ಯಾ ಲಕ್ಷ್ಮಿ, ಸಂತಾನ ಲಕ್ಷ್ಮಿ, ವಿಜಯ ಲಕ್ಷ್ಮಿ, ಧಾನ್ಯ ಲಕ್ಷ್ಮಿ ಮತ್ತು ಗಜ ಲಕ್ಷ್ಮಿ ಈ ಎಂಟು ರೂಪಗಳುಳ್ಳ ವಿಗ್ರಹವನ್ನೋ ಅಥವಾ ಚಿಕ್ಕ ಚಿಕ್ಕ ಫೋಟೋಗಳನ್ನು ಇಟ್ಟು ಪೂಜೆ ಸಲ್ಲಿಸಬಹುದು. ಇದು ಅಲಂಕಾರದೊಂದಿಗೆ ಪರಿಪೂರ್ಣತೆಯನ್ನೂ ನೀಡುತ್ತದೆ.

5. ಕೆಂಪು ಬಣ್ಣ: ಲಕ್ಷ್ಮಿಯನ್ನು ಪ್ರತಿನಿಧಿಸುವ ಮತ್ತು ತುಂಬಾ ವಿಶೇಷವಾಗಿ ಕಾಣಿಸುವ ಕೆಂಪು ಬಣ್ಣವನ್ನು ಕೋಣೆಯಲ್ಲಿ ಅಲಂಕರಿಸಿದರೆ ಪೂಜಾ ಕೋಣೆಗೆ ಕಳೆಬಂದಂತೆ. ಕೆಂಪು ಬಣ್ಣದ ಹೂವುಗಳು, ರಂಗೋಲಿಗೆ ಕೆಂಪು ಬಣ್ಣ ಹಾಗೂ ಕೆಂಪು ಬಣ್ಣದ ಶೇಡ್ ಇರುವ ಸೀರೆ ಮತ್ತು ಬಳೆ ತೊಡಿಸಿದರೆ ಚೆಂದ. ಆದರೆ ಬಣ್ಣ ಕಣ್ಣು ಕುಕ್ಕುವಂತಿರಬಾರದು. ಆಯ್ಕೆಯಲ್ಲಿ ಎಚ್ಚರಿಕೆಯಿರಲಿ.

ಈ ಹಬ್ಬವು ಎಲ್ಲರಿಗೂ ಸುಖ ಶಾಂತಿಯನ್ನು ತರಲಿ ಎಂದು ಹಾರೈಸುತ್ತೇನೆ.

Rajesh YN, Mallupura My comment on Mr.Tharanath's mail on Varamahalaxmi Vratha

1.This forum being state sponsored forum(started by govt) we cannot give nonsecular thoughts in the forum.

2. Being the science teacher I strongly reject idea of worshiping God to gain back something which i think is blind belief.

3. But I do appreciate the Aesthetic sense presence in the rituals, which may bring peace to the mind (you can't find peace when you spent so much money to celebrate, unless you have buying syndrome)


Tharanath Achar, Belthangady

Sir, I want to clarify something about my post.

Being a science student I do not worship or believe in the existence of extra terrestrial things if any. I am a pure secular person who only believe in the spirit of science. I believe the conflict or confluence of thoughts arises because of our own perception of ideas. Any idea which may bring short or long term happiness is aesthetic something behind it. A wish for well being is something we convey to others may or may not be backed by the notion or mention of something very nice to the well-wisher or receiver. The intention behind my post was to wish the forum well, but I the way I did it might have irritated someone who has strong scientific temper. Also I did make a mistake by copying and pasting the idea from a ritualistic site without giving a second thought - I was busy at that moment- I had a look at the script only after pressing the send button and felt sorry myself -- sorry because the content had to do something with rituals- I noticed it only later. I am sorry! My intension was not to sell the ritualistic idea. Please note this down - It is not my own idea -it is copied and pasted from a site -you can find it out easily through google.

I read again the content of the post displayed at bottom of this page - and found the depth of difference between the ritualistic and scientific brain.)

I appreciate Mr.Rajesh's 2nd comment. The intention behind the point is what a teacher (Science or Social or whatever ) should understand first and prompt his students on that line. I am doing it (gitting rid of blind beliefs) on my own for the last ten years and personally I feel very bad about myself for being thrown out of home for being an atheist. But in a society where blind belief or other form of unscientific but society sponsored ideals prevail, the scientific temper find it hard to shine properly. But I am pure secular.

I support 50% of 3rd comment. Peace of mind is not supported by rituals for which have to pay. Peace of mind is only a borrowed idea in the context of rituals. The peace of mind or sense of well-being is flows easily when you witness good in our own or actions of others. And about Mr.Rajesh's first comment. It is true that the maths science forum is sponsored by the state government but not google groups. Google groups may become a sound discussion forum relating to our subjects. Again, discussion is not sponsored by anyone but ourselves. You may or may not accept my ideas. You may reject my ideas altogether if it doesn't belong to the ethics or limits of the forum. The content of my post is not mine. If sending greetings or well-wishes to a forum on certain occasions is a subject to comments, let us stop doing that. Finally, please don't feel that I attracted someone to discuss or comment by posting some vague ideas. Also don't feel that the person who posted the wish is an blind believer. I had nothing at hand or head at the time of posting.Now it is clear that reckless copying and pasting and posting creates issues and controversies. I had only one idea--- that is wishing.

Thank you for your comments! Probably discussion is needed to keep our intellect healthy. Let us stop this topic here and now. It is not our subject. I am sorry if you are personally annoyed. I wish you all a very happy Independence day.

Ranjani Ranganathan IT for Change

Both your comments are much appreciated. They have both contributed to the forum in very significant ways
- Tharanath's good wishes and efforts to communicate with the community and the generosity with which he has accepted feedback
- Active participation by Rajesh and pointing out areas where we need to be clear about the sharing in the forum

While the issue of God or "blind" belief can be discussed elsewhere, I want to point out that what we all need to be careful about is how we evaluate any belief or process. We are all aware of strong, inflexible positions that even scientists hold when proving or disproving theories. One look at the history of science will tell us the story.

More than belief or disbelief, it is scientific temper that will allow us all to function effectively as teachers. Scientific temper does not mean the inclusion or exclusion of any idea or theory; rather, the ability to observe as clearly as possible, evaluate all dimensions of a problem and arrive at a conclusion. To me, it seems that scientific temper must also include tentativeness to critically evaluate all positions (including our own) and willingness to correct/ revise our understanding when presented with new observations and facts.

Having said all that, I would still want to wish all the teachers much joy and happiness - I see varamahalakshmi puja as an opportunity to do that.


Why is the speed of light constant

How is the speed of light not relative?

There are a few ways to answer this question.
1. Einstein knew what he was saying. He was correct and so this postulate is correct.  (This is not a silly answer - needs to be considered very carefully as a way in which any model can be used to explain observed phenomena).

2. Solving Maxwell's equations of electromagnetism, we get the speed of light to be 1/sqrt( μ0 /Є0) both of which are constants. These are universal constants, not dependent on the frame of reference. If they are universal constants and not dependent on the frame of reference, then the value calculated from there must also be constant.  Hence, the speed of light is constant.

3. The consequences of this postulate have been verified and found to be true.  For instance time dilation and space contraction.  The logic goes like this.  I make hypothesis A. Because of that, D, E and F will happen.  So, if I notice D,E and F happening, then A must be true.  Do you notice that #1 and #3 are different ways of saying the same thing?

4. When we assume constancy or otherwise of speed of light, we assume that other aspects/ dimensions remain constant.  If time is dilated, how can we ask the question if the speed is the same.  When what I know and measure as time would have changed? (Btw - a physics teacher once told me we do not know what time is - if you have any thoughts on time, please share)

5.  Last but not the least, there is a mathematical way to prove this...(thanks to the internet!).  I am attaching a very simple and neat proof of the constant speed of light.  Please read and enjoy..

By now, we would have come to the opinion that atleast part of the answer to this question is philosophical in nature.  If we remember light is not a thing, then the way we will ask questions about light will be different.

More information can be found in 1. E = mc2  by David Bodanis...a very interesting book on how the theory of relativity was "hidden" in Maxwell's laws all the time. 2. http://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&ved=0CGAQFjAG&url=http%3A%2F%2Fphysics.unipune.ernet.in%2F~phyed%2F24.3%2F24.3_Behera.pdf&ei=ziTjUK-SLszJrAefjIGgBw&usg=AFQjCNGXrLlXFaM1fYwFRrastjQ8pP4d-g&bvm=bv.1355534169,d.bmk&cad=rja



Sankranthi and summer solstice

Ranjani Ranganathan ITfC
Sankranthi wishes to all of you!!

Have you wondered about why the ascending movement of the sun (days getting longer - the traditional name ...uttarayana kalam meaning - the sun starts moving north) is celebrated on this day whereas the winter solstice is on Dec 22nd. And days start getting longer from then...

Of course, in some parts of India, it is also the harvest festival...

Rajesh YN Mallupura, Mysore
It is interesting to know about the tilt and Makara sankranti. But I always wonder only this fest in India repeats on particular date. The other festivals are relative to Lunar Calender. What about this?

Radha Narve, Begur, Bangalore
I reffered some sites and tried to answer .is that correct? The traditional Indian Calendar is based on lunar positions, Sankranti is a solar event. So while dates of all Hindu festivals keep changing as per the gregorian calender, the date of Makar Sankranti remains constant over a long term, 14 January. Makar Sankranti is celebrated in the Hindu Calendar month of magha. The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted .

Ranjani Ranganathan ITfC
From what I understand, the sankranthi is based on sidereal time (calculated with respect to the stars). The movement of the sun with respect to the signs of the zodiac is what is talked about as sankranthi. There are 12 movements possible (12 zodiacal signs). The makara sankranthi is considered to be holy because of the ending of winter, harvest season in parts of India, ending of the NE monsoon, etc.

I also wondered about why it falls on the same day... The Hindu calendar is also based based on the movement of the sun with respect to the stars (within a new moon - new moon cycle). Hence makar sankranthi always falls on a particular day of the lunar calendar though it is not calculated based on that. For example, in Tamilnadu is coincides with the beginning of the month of "Thai".

It is for this reason that some people believe lunar calendars are more accurate than the gregorian calendar (Jan- Dec).

The gregorian calendar is based on the equinox positions and this can change with earth's precession around its axis. For example, in 1903 , the date of the winter solstice was Dec 23rd and it is expected to be on Dec 20 in 2096 (Source - see link http://en.wikipedia.org/wiki/Gregorian_calendar#Accuracy) The solstice is based simply on the day and night changes of the sun with respect to the earth, based on the above method of calculation of equinoxes.

Over thousands of years, the position of the stars with respect to the earth has changed due to the precession of the earth. So, one theory is that the date of the sankranthi may have moved with respect to the Gregorian calendar. (Source - see link http://en.wikipedia.org/wiki/Precession_of_equinoxes#Indian_views)

Sankranthi does not change with respect to the Indian calendar months because the lunar months also are based on sidereal calculations.

This is an interesting question and we need to find out more....interestingly, is this the only Indian festival based on this calculation?

What is electric current?

Response 1:Electrical current is a measure of the amount of electrical charge transferred per unit time. It represents the flow of electrons through a conductive material. The direction of electric current is opposite to the direction of electrons.

Response 2:It will be more apropriate to say that the electric field moves instead of the electrons. _ The electric current is- The movement of the electric field in the conductor not the electrons. We know that electricity almost moves in the speed of light. At this speed the electrons would get such a momentum that a small bent in the conductor, is enough to make electron to get out of the path because of inertia of linear motion. Think about it.( Needs discussion)

Response 3: One way to think of this is to think of the electric field as an information field.

Let us say we are in a large hall with a few exit doors. Once a programme is over everyone gets up and attempts to move towards the nearest exit. It is not that everyone gets up one after the other and goes to the door. The information to get up and move is communicated simultaneously. Similarly it is not that the tubelight glows because the electrons move from one end to another. We know that the drift velocity of the electrons is different and this is not what we call current. Rather information about how the electrons can move is communicated when the potential difference is applied. And this information travels at the speed of light.

Instead of electricity, it may be more accurate to say that the information is communicated across the electric field at the speed of light.

This understanding of the "field" concept as an information field is crucial to the understanding of electromagnetism.