Unit request: g
Opened this issue · 6 comments
In biology, centrifugation is often specified in multiples of g rather than m/s^2.
Could OM-2 please add a factored unit for g as an alternative? This would be a conversion unit like a foot is to a meter, relating to m/s^2 with a factor of g = 9.80665 m/s2
Thanks for this issue. It's a very important issue. I have to think about how to arrange this because g is actually a quantity, not a unit. It's a constant. We see in practice that constants are used as units, so I think we should definitely do something with this issue. But I don't know exactly how yet. Maybe we should just define constants as units. I have to think about it. I'll come back to this issue soon, the intention is this week.
Thank you for attending to this!
Thinking about the resolution: not all constants are used as units. Perhaps every constant that is often used as a unit could be given two types, such that it can be both a constant and a unit?
Thanx too!
Ah yes, that it's both a unit and a quantity. Good suggestion. The consequence however is that it will have many properties, I have to think about that.
Defining them twice (as quantity and as unit) which I suggested in my previous comment leads to redundancy. We should not do that I think.
I'm now thinking about having measures (om:Measure, e.g. '3 kg', '4 m', etc.) refer not only to a unit, but also to a quantity (e.g. '5 g'). Conversion can also be supported because the quantities involved – constants – could have a definition in terms of other units. Then we have to expand the domain of the properties om:hasFactor and om:hasUnit to om:Quantity (a unit has two properties to define it terms of other units: om:hasFactor for e.g. 0.9144 and om:hasUnit for e.g. om:metre to define om:yard.
Sorry, it has been a while that we have discussed this issue. I still think it is a very important issue. Using constants as units happens in many domains.
Would you have feedback to my last suggestion, Jake, to let measures refer to either units or quantities?
How is this represented with tyto/om? is it tyto.om.g? I need it for the Myers Genetic Logic Lab collaborator protocols. @HajoRijgersberg @jakebeal
Hi Sai,
What is tyto?