| It seems there are multiple definitions of equality.
1) Within an idealized framework, can we consider to things equal? If we define in an idealized framework that two things can be, or are, equal, then they are equal, by definition. However, this may not be what you are getting at.
2) Are there equal things within the physical environment? Now we seem to be asking- is the physical environment composed of items that exist as a form of an idealized framework? Is physical reality a manifestation of a platonic ideal? For instance- are any two atoms actually the same? It seems that they may or may not be- but this is the heart of your question, at least in the simplest form. If an atom has a "half life" and may decay, is it the same as another atom which was formed at a different time, but is the same in all other respects? I am not sure what physics say about these two atoms- is one more likely to decay than the other because of different initial start times, or not? Perhaps this answer is unknown as well.
Now as soon as you consider a larger object- say a penny- are any two pennies equal? Obviously they are microscopically different. But as far as their interaction in the environment, it would appear that they are identical for human purposes. If the penny only functions within the human sphere, perhaps they are identical after all.  |