I found the video on waste sorting a really interesting. I never gave much thought to how our inorganic waste was sorted but learnt that there are many scientific principles that underpin the process. That they are sorted through the means of size and weight, that magnetism helps sort metals and that plastics can be sorted by the means of optical properties; that is in their capacity to allow red light to pass through.
I also learnt the importance of dirt to a healthy ecosystem, that for there to be a viable food web the organisms on the first trophic level must be healthy and this comes from healthy dirt. I knew of the Nitrogen Cycle as a concept but didn’t truly understand its importance. But now know that Nitrogen is responsible for the growth of all living things and without it plants cannot manufacture proteins.