Sunday, 31 May 2015

Sun, shadows and time...

We've been learning about time for maths and the sun in inquiry. On Thursday for both, we looked at different ways to tell the time.  We went outside at 9.40am and drew around one another's shadows with chalk.  We recorded this...

Standing with our artist buddies ... it is 9.40am
Then we went back out at 11.40.  Our shadows had moved. They had moved anti-clockwise and had gotten a lot shorter.

We checked them again throughout the day, noticing the same thing.  Our shadows moved.  At 2.40pm we took our final inspection and were very surprised to notice the difference from where they were that morning.

Our shadows can act like a sun dial ... an 'old-fashioned' way of being able to tell the time from the shadows the sun casts on the ground. At different times of the day when the sun is either high or low in the sky (because of the Earth's tilt and that it moves around the sun throughout the day), the shadows are in different places.  

When we went to Carter Observatory on Friday, we were able to try out the 'Sundial of Human Involvement' that is outside.  It is made of big rocks with metal numbers (for hours) placed in a huge semi-circle on the ground.  In the middle is a metal plate with the months of the year and marks to indicate the day.  You stand facing away from the sun on the day of the year (so Aaruchya stood on 29 May), hold your hands together high above your head (as thin as a pin) and look to see where your shadow is cast.  Aaruchya's shadow told us it was about 12.03.  We checked Mrs P's watch and it said the same time. We were amazed.  Hope had a go too, but we couldn't find her shadow. We realised the sun was covered by clouds. We asked Ken (our Carter educator) how people could tell the time on a sundial if it is cloudy. He suggested they would have to guess the time, or at night time may be able to use the stars or position of the moon for an indication.  

We thought the sundial was a cool way to tell the time and to illustrate what we learnt on Thursday at school about shadows and time.  

click on photo to make it bigger

1 comment:

  1. Cater Observatory seems helped on learning in addition Space. Good timing. Thanks for sharing.