According to quantum mechanics, of course it can,. It is indeed both particle and wave: except that this is so only so long as it is not observed. The moment it is observed it reduces to one or the other aspect of its intrinsic duality in the non-observed state.
A rough analogy would be this: Can a person be both good and bad? The answer is “of course one can,” but when the person does something, the individual is detected to be either good or bad.
It is this almost fantastic nature of reality about microcosmic entities that makes QM so strange or spooky, and prompted Bohr, Feynman and others to say that anyone who says he/she understands QM doesn’t know what he/she is talking about.
My own interpretation of this oft-quoted and ill-understood quip is that QM simply does not conform to our evolutionarily generated cerebral notions of perceived reality, from which, like our spatially constrained three dimensionality, we simply can’t experientially escape.
The inability to even conceive that the world can be different from what we are accustomed to is one of our built-in epistemological handicaps, not unlike the removable narrow vision that all cultures and religions should be exactly like our own.
Even those who have overcome this bias often feel that all opinions/views/understandings on any topic should be exactly like what they themselves entertain and cherish.
April 13, 2011