Gathering shadow data for school investigation

[MarkyMark]

Hello everyone, my first post here with the intention of seeking some advice. Apologies if I have posted in the wrong forum. I'm making short films for school pupils to learn from whilst we are in the midst of the pandemic.

 

I need data for a science investigation. Imagine a plunger placed on the ground outside in the sun. The length of shadow as well as the angle of this shadow changes as the sun moves across the sky. 

 

I want to record the length and angle over the course of a day - at 8am, 10am, 12pm, 2pm and 4pm. Now imagine I want to record the data for not just that day but the next day and every other day for the next 5 weeks! Can anyone take a guess as to whether this data can be modelled and if so, how hard would it be? 

 

I'm assuming the investigation is taking place in the northern hemisphere in a US state such as sunny California, perhaps in the summertime post summer solstice. I am based in Scotland where there is not consistent sun over the course of a day let alone weeks so gathering real data is nigh impossible here.

 

If anyone has any thoughts, it would be great to hear from you! Likewise, if you can point me in the direction of a more suitable forum/ experts, that would be really appreciated. 

[CountryBoy]

So basically you want to measure the position of the sun, relative to you, at 5 different times a day for a total of 35 days.  Yes, that's an interesting experiment.  You will want to write down the length of the shadow as well as the  angle with some fixed line.  I conjecture that you will see both length and angle almost repeating each day.  Think about why they repeat and why the do not repeat exactly.

[OceanBreeze]

On 1/5/2021 at 8:35 PM, MarkyMark said:

Hello everyone, my first post here with the intention of seeking some advice. Apologies if I have posted in the wrong forum. I'm making short films for school pupils to learn from whilst we are in the midst of the pandemic.

 

I need data for a science investigation. Imagine a plunger placed on the ground outside in the sun. The length of shadow as well as the angle of this shadow changes as the sun moves across the sky. 

 

I want to record the length and angle over the course of a day - at 8am, 10am, 12pm, 2pm and 4pm. Now imagine I want to record the data for not just that day but the next day and every other day for the next 5 weeks! Can anyone take a guess as to whether this data can be modelled and if so, how hard would it be? 

 

I'm assuming the investigation is taking place in the northern hemisphere in a US state such as sunny California, perhaps in the summertime post summer solstice. I am based in Scotland where there is not consistent sun over the course of a day let alone weeks so gathering real data is nigh impossible here.

 

If anyone has any thoughts, it would be great to hear from you! Likewise, if you can point me in the direction of a more suitable forum/ experts, that would be really appreciated. 

If you were to plot the sun’s position in this way over a period of one year, you would plot a Solar Analemma, figure 8 curve. This is because the earth orbits around the Sun on an elliptical path while also revolving around the Sun on an axial tilt of around 23.4 degrees.

 

 

As for modelling the position versus real time plotting, the equations are well developed but rather complicated to use.

 

[MarkyMark]

Thanks to both CountryBoy and OceanBreeze for your replies. I think I have moved on a little with the experiment - or at least I hope I have! I was recommended a shadow calculator, and from that, discovered a sun calculator that I believe can assist. As I understand it, I can use it to calculate not only the shadow angle of the object at any time of day (take the azimuth angle and +/- 180 from it) but also the length of shadow relative to the length of the object. 

I'm currently calculating the daily data. I general the azimuth stays the same while the lengths slowly change. 

https://www.suncalc.org/#/55.8637,-4.2573,6.746666666666666/2021.07.05/09:56/0.52/3

I'm now trying to seek verification that my process is correct and that I can go ahead with creating 5 weeks worth of data!

[OceanBreeze]

Very nice calculator! I will bookmark that for future use.

I have calculated that the Toby Jug on Hope Street will be opening soon. Cheers!

[MarkyMark]

Hahah.. sadly with full lockdown here that won't be happening. Besides there's a nicer place round the corner 😛

I think I'm on the right lines with the calculator!