SEM

Sun Earth Moon 

Installation 

Usage

सहस्रचंद्रदर्शन

सहस्रचंद्रदर्शन हा पोर्णिमेशी संबंधित असलेला आणखीन एक समारंभ.

एखाद्या व्यक्तीच्या आयुष्यात १००० पौर्णिमा येऊन गेल्या की हा समारंभ करता येतो. व्यक्तीच्या आयुष्यात या पौर्णिमा फक्त यायला हव्यात, त्या पौर्णिमांच्या दिवशी त्याने चंद्रदर्शन घ्यायलाच पाहिजे असे नाही.

१००० पौर्णिमा कशा मोजायच्या हे ठरविण्या आधी इंग्रजी व भारतीय दिनदर्शिके विषयी थोडेसे ..

आपल्या परिचयाचे  इंग्रजी महिने हे पृथ्वीच्या सूर्याभोवती होणार्‍या प्रदक्षणेवर आधारलेले आहेत. भारतीय पंचांगात महिने हे चंद्राच्या पृथ्वीभोवती होणार्‍या प्रदक्षणेवरून ठरतात. चंद्र पृथ्वीभोवतीची एक प्रदक्षिणा सुमारे २७.३ दिवसात पूर्ण करतो. पण पृथ्वीसुद्धा सूर्याभोवती फिरत असल्यामुळे पृथ्वीच्या आकाशात त्याच ठिकाणी यायला चंद्राला जवळजवळ २९.५ दिवस लागतात.

अमावास्येपासून परत आमावास्येपर्यंत लागणारा वेळ , हाच आपला एक मराठी महिना , यालाच चांद्रमास असे पण म्हणतात. चांद्र मास हा तीस दिवसांचा (प्रत्यक्षात साडे एकोणतीस दिवसांचा) असतो, तर चांद्र वर्ष ३६० दिवसांचे (प्रत्यक्षात ३५४ दिवसांचे). हे सूर्याधारित सौरवर्षापेक्षा ११ दिवसांनी लहान असते. सूर्यवर्षाच्या बरोबर येण्यासाठी साधारणपणे दर (सुमारे) ३३ महिन्यांनी अधिक चांद्रमास येतो.

एका इंग्रजी वर्षात १२ किंवा १३ पौर्णिमा येतात. १३ वि पौर्णिमा ५ वर्षातून दोनदा येते. 

म्हणजे साधारणपणे व्यक्तीचे वय ८० वर्षे आणि आठ महिने झाले की त्यानंतर कधीही त्याच्या सहस्रचंद्रदर्शनाचा समारंभ करता येतो.

इथे १००० पौर्णिमा मोजण्यासाठी इंग्रजी दिनदर्शिकेची मदत घेतली आहे. त्यामुळे १००० वि पौर्णिमा कुठल्या इंग्रजी तारखेस येईल हे काढणे सुलभ ठरते.

तुमची जन्मतारीख व वेळ दिली १००० वि पौर्णिमा कधी येईल ते कळते . याबरोबरच इतर माहिती पण दिली आहे.

https://textbookscience.pythonanywhere.com/

Source of data

Base data for this utility was fetched from '
Astronomical Applications Department' of the U.S. Naval Observatory. Data included dates related to primary phases of the moon from 1700 to 2100. Rest API service was used to fetch the data for the years 1930 to 2100 and curated to retain only full moon information. Original data is available in Universal Time. This was converted to Indian Standard Time by adding 5 hours and 30 minutes.

Python programming language was used to parse and calculate other details required for this exercise.

• https://aa.usno.navy.mil/data/MoonPhases

Basic Astronomy

 Creations related to Sun, Earth, Moon and other planets in the solar system and related events.

Sun Earth Moon Model

 3D Printed Model - Sun, Moon and Earth

3. Inner Planets

 Phases of moon

5. Zero Shadow Day - 2022

6. Same side of Moon

7. Uttarayan and Dakshinayan - Northward and Southward Movement of the SUN

8. Umbra / Penumbra

Movement of Shadows - clockwise or anticlockwise

Automata - Mechanical Toys for the classroom

 How can I make use of toys as a medium to understand concepts in our textbook ? This one question led me to my exciting journey in the world of automata toys, which started around a year back. Here is what I learnt so far.….

Toys are fun, and fun is important ! By definition, toys are for children but they can also be for adults. Automata, also known as mechanical toys, have universal appeal which transcends all ages. Fascination lies in a simple automated movement, whether the mechanism is hidden or revealed. 

Automata toys are “story telling mechanical sculptures”. These are child-tailored communication devices, much appreciated by the children and easy to realize in the classroom. These whimsical and wonderful machines combine art, play, humor, science and engineering. Automata toys are complete units that typically tell a short story—someone chopping wood, a horse running, men fishing, etc. They utilize a combination of levers, cranks, linkages, cams, shafts, ratchets, gearing, and drives.  Building automata toys is a good example of integrating science and art with an activity. For  learners, the narrative and decorative aspects are as important as the mechanical elements. It is an involved process that has a lot of potential for stimulating the imagination of students and providing a fun, practical learning platform.

The Automata toy consists of two parts: its top features and an underlying mechanical assembly. In the mechanical part, simple machine elements like cams, levers and linkages are used in a playful way. Features are brought to life with the help of paper figures, colors and other craft ideas.

Keywords like creative thinking, verbal and non-verbal communication, adaptability, choice-making and more came to life in the automata workshops I conducted with teachers as well as students.  Participants are guided to design and build their own automata using everyday material like corrugated sheet, sticks and straws.  

Typical introductory session on this topic lasts for 2-3 hours in which participants work in teams. To begin with, the team discusses an event, process or abstract concept to work on. Lots of ideas are discussed and debated during this phase. Once an idea is finalized, the team comes up with a short story. Students choose stories based on animals, sports, hobbies or festivals while teachers try to  choose concepts from the textbook. Story dictates how automata toy will come to life. Some parts of the story represent static parts while other parts are candidates for movement.  Action verbs shortlisted from the story will drive the movement of automata toy.  

It is said that a picture is worth a thousand words. Drawing a picture of an automata toy and related mechanism is the most important step in the whole process.  Team members can express their ideas in a better way through pictures. Some gaps are also identified at this juncture. Picture or schematic of the toy gives team members an opportunity to communicate how they feel about the construction process to be followed. In some instances, teams chose different action verbs as the selected one seemed too difficult to build.  

With a rough blueprint of the toy ready, the team gathers input material like a box of corrugated sheet, wheels made from foam sheet, kebab sticks and thick paper. Members having inclination on the art side take up work like character drawing, cutting and painting. Others start connecting wheels, axles and the related motion part. Individual contribution in the area of one’s choice can be seen in this phase. Any creative work involves challenges, difficulties and rewards. Building automata toy step offers these in abundance. Team normally goes through a couple of iterations before the automata toy comes to life.  Many times it is only half done for want of time but joy of achieving part of the functionality is none the less visible.  

In many instances, teams collaborate with other teams as well to learn from their creations as well as offer help in fixing things for others. Towards the end of the workshop, it's fulfilling to see your working automata toy placed next to the other toys. Participants enjoy the process more than the final automata toy itself. Many feel that making automata toy is not a very easy process which they initially thought but it is a satisfying and rewarding thing to do, especially when it finally works !

There is much more to learn and do in this field. Difficult to understand concepts in the textbook can be taken up as a theme for Automata toy. This automata toy can complement as a teaching aid in the classroom.  Static models created by students as a part of a project can be brought to life by adding motion in the same.  Automata building activity allowed students to tinker with lots of things, guided by whim, imagination and curiosity.  While tinkering, there are no instructions - but there are also no failures, no right or wrong ways of doing things. It's all about figuring out how things work and reworking them.

Note : Creations done by students and teachers are available at the following URL 

https://tinyurl.com/automatatoys

Apps for Science Classroom

Experimentation is a critical aspect of any science education. Smartphone can be an effective teaching aids in this journey. Concept clarification activities can include data feeds from various sensors in smartphone.
Gathering data and analyzing the same forms a key phase in any enquiry based activity.  Many smartphone apps help students with these phases.

More than 40 physical measurements are possible with the sensors available in smartphone.

Sensors

Accelerometer

• Linear Acceleration X
• Linear Acceleration Y
• Linear Acceleration Z

Microphone

• Oscilogram
• Fundamental Frequency
• Frequency Spectrum
• Sound Volume

Colorimeter

• Colors
• Color Spectrum

GPS

• Latitude
• Longitude
• Precision
• Speed
• Altitude

Gyroscope

• Rotation X
• Rotation Y
• Rotation Z

Luxmeter

• Illumination 
• Point Luminance

Inclinometer

• Tilt

Compass

• Orientation

Pedometer

• Number of steps

Camera

• Pictures
• Videos

Session Activities

1. Cut equilateral triangle using card sheet and measure each angle with Inclinometer.
2. Rest your smartphone against the wall and measure the angle between wall and floor.
3. Explore how intensity of Sound varies with distance.
4. Explore more about linear acceleration with the help of your smartphone.

Other Activities

• Measuring the duration of freefall.
• Measure the length of a pendulum from pivot to center of mass
• Use a Magnetic Ruler to measure the speed of things
• Calculate the speed of a rolling object
• Turn your smartphone into a SONAR device
• Measuring the speed of an elevator
• Measure the speed of sound
• Measure the rotation rate of a fidget spinner
• Build and 'speed test' your own balloon powered car
• Build and test an Earthquake proof model building foundation
•  Spin, spin, spin — To measure centripetal acceleration using the accelerometer app...
•  Tick, tock - Proximity sensor to find out period of the pendulum

Videos

1.  Science Activities with Apps
2. Phyphox app playlist 
3. Session video for activity using FizziQ

Apps on playstore

1. Fizziq
2. Science Journal 
3. Phyphox
4. Physics Toolbox
5. SensorBox for Andorid
6. AndroSensor

Modelling phases of the moon

 In an earlier video, we explored the movement of earth and moon with respect to the SUN. 

Red ball representing the sun can be replaced with the flashlight of the cell phone. Now we can observe the play of shadows as Earth and Moon change positions.  This arrangement does not allow us to view the moon from Earth. Let us place another phone in place of earth and a larger ball in place of a small moon. 

In fact we don't need this setupl.  Instead, we will use the flashlight of this phone to represent sunlight.

On this turntable made from corrugated sheet, a small plastic ball represents the moon. 

This second phone represents Earth. Camera on this second mobile phone will enable us to view phases of the moon as it revolves around the Earth. 

Height of the light source needs adjustment at some locations to avoid the shadow of Earth on the moon. 

Let us start with the New Moon. 

For better viewing, we will move the flashlight farther. 

Frame on the left side shows the top view while the frame on the right side shows the moon as seen from Earth.

Like Earth, the Moon has a day side and a night side, which change as the Moon rotates. The Sun always illuminates half of the Moon while the other half remains dark, but how much we are able to see of that illuminated half changes as the Moon travels through its orbit. We call it a Phase. 

The Moon has eight phases in a lunar month: four primary and four intermediate phases.

There are eight phases.  in order, new Moon, waxing crescent, first quarter, waxing gibbous, full Moon, waning gibbous, third quarter and waning crescent. The cycle repeats once a month (every 29.5 days).

New Moon

This is the invisible phase of the Moon, with the illuminated side of the Moon facing the Sun and the night side facing Earth. In this phase, the Moon is in the same part of the sky as the Sun and rises and sets with the Sun. Not only is the illuminated side facing away from the Earth, it’s also up during the day! Remember, in this phase, the Moon doesn’t usually pass directly between Earth and the Sun, due to the inclination of the Moon’s orbit. It only passes near the Sun from our perspective on Earth.

Waxing Crescent

This silver sliver of a Moon occurs when the illuminated half of the Moon faces mostly away from Earth, with only a tiny portion visible to us from Earth. It grows daily as the Moon’s orbit carries the Moon’s dayside farther into view. Every day, the Moon rises a little bit later.

Waxing Gibbous

Now most of the Moon’s dayside has come into view, and the Moon appears brighter in the sky.

Full Moon

This is as close as we come to seeing the Sun’s illumination of the entire day side of the Moon (so, technically, this would be the real half moon). The Moon is opposite the Sun, as viewed from Earth, revealing the Moon’s dayside. A full moon rises around sunset and sets around sunrise. The Moon will appear full for a couple of days.

Waning Gibbous

As the Moon begins its journey back toward the Sun, the opposite side of the Moon now reflects the Moon’s light. The lighted side appears to shrink, but the Moon’s orbit is simply carrying it out of view from our perspective. The Moon rises later and later each night.

Last Quarter

The Moon looks like it’s half illuminated from the perspective of Earth, but really you’re seeing half of the half of the Moon that’s illuminated by the Sun ― or a quarter. A last quarter moon, also known as a third quarter moon, rises around midnight and sets around noon.

Waning Crescent

The Moon is nearly back to the point in its orbit where its dayside directly faces the Sun, and all that we see from our perspective is a thin curve.

Variations.

You can perform this activity with balls of different sizes, changing the position of the SUN as well.

Do try this at home.

I captured phases of the moon with my camera during this activity as well.

Ball with indentations was 3D printed for this activity.

Thank You.

India's National Solar Calender

Let us understand more about this calendar with the help of a model.

 

In earlier videos, we explored key events associated with the Sun, Earth and Moon.

Relative locations were discussed as per Gregorian calendar as well as Hindu Calendar. 

In this video, let us explore one more calendar, India’s  National Solar calendar. 

We will focus on the movement of Earth and Sun during a span of one year and arrangement of months related to the same.

Months of Gregorian calendar are listed on the outer rim like this. 

January, February, March, April and so on …

Unlike the Luni-solar based Hindu Calendar, the National Solar Calendar is based on the movement of Earth around the SUN.

1st day of this calendar starts on the Vernal Equinox, when days and nights are equal. 

This day happens to be the 22nd March of the Gregorian Calendar. 

There are twelve months of the National Solar Calendar. 

They are named as 

Chaitra,

Vaishakh

Jeshtya

Aashadh

Shravan

Bhadra

Ashwin

Kartik

Agrahayan

Paush

Magh

Falgun.

First month of Chaitra has 30 days while the next five months marked in Green have 31 days.

Remaining months marked in yellow are 30 days each.

Each month has a fixed start date associated with the Gregorian calendar. 

Chaitra starts on 22nd March. 

Vaishakh  starts on 21st april

Jeshtya  starts on 22 May

Aashadh  starts on 22 June

Shravan  starts on 23 July

Bhadrapad  starts on 23 August

Ashwin  starts on 23 Sept

Kartik starts on 23 Oct

Instead of Margshirsh, this month is called Agrahayan and starts on  22 Nov

Paush starts on  22 Dec 

Magh on 21st Jan

And Falgun on 20th Feb.

All months together account for 365 days. 

When there is a leap year. Chaitra has 31 days instead of 30 and starts on 21st March of Gregorian Calendar. 

Sun spends more time in the Northern Hemisphere hence these months are 31 days each.

Now let us view the position of Earth’s axis from the front side. 

On 21st March, Start of Chaitra month, both hemisphere receive equal amount of light. - Equinox.

On 22nd June, Earth’s axis is tilted towards the sun. Days are longer and nights shorter in Northern Hemisphere. This day is also the first day of Aashadh.

Dakshinayan starts from this date as well.

On 23rd  September there is another equinox. This is also the start of Ashwin Month. 

On 22nd December, Earth’s axis is tilted away from the SUN. This is also the start of Paush month. 

How about seasons. 

National solar calendar has identified six seasons associated with 2 months each. 

Grishma - Summary - Vaishakh and Jeshtya

Varsha - Rainy Season - Aashadh and Shravan

Sharat - Autumn - Bhadra and Ashwin 

Hemant - Kartik and Margashirsh or Agrahayan

Shishir - Winter - Paush and Maagh

Vasanta - Spring - Falgun and Chaitra.

Sun spends more time in Northern Hemisphere than Southern Hemisphere.  hence these months have 31 days 

Sequence of the year is as per the Shalivahan Shak. 

More information is available on the website https://www.rdpm.in/ as well. 

 

Reference

https://www.marathisrushti.com/articles/indias-national-solar-calendar/