Need class for non-biological material entities bigger than molecular entities

[cmungall]

[I will flesh out ticket later]

where do these go in COB?

• nanoparticle (currently in CHEBI)
• mixtures (currently in CHEBI, but problematic - see https://github.com/ebi-chebi/ChEBI/issues/3293)
• mineral
• piece of rock (ENVO)
• portion of water (ENVO)

Currently these would go directly under ME

[bpeters42]

I had previously proposed definitions for material entities such as 'makromolecular material entity', where 'makro' signifies that removing one molecule from the entity does not change its identity. For mineral, piece of rock, portion of water, this should all work. 'nanoparticle and 'mixtures' are special in their own ways, aka clusterfucks.

[bpeters42]

There were concerns raised about my proposal in the past, and it was shelved. I am unable to recall what they were, but there will be plenty of edge cases where my proposal will become problematic. However, I still think we should implement something like it simply because this is how scientists work. Going from a subatomic worldview to an atomic one to a molecular one to a macromolecular one in each case comes with approximations that make things identical based on different criteria. I continue to believe that reflecting this in our ontological definitions is the best way forward. And as with many other things, we should acknowledge and capture edge cases, but not make them force us to give up on a useful overall hierarchy

[jamesaoverton]

See #33.

We have discussion notes from the OBO Core Workshop at ICBO 2019: https://docs.google.com/document/d/1P8uMYDqWxJ4Qh6QKD6ZeYqziNTbxsMHuN-s8jn7soEk/edit