Matter is anything that has mass (meaning the thing can be weighed) and occupies space. In our universal reality matter and space always come as a pair for without each other’s presence neither would have any definable meaning in our physical reality.
How old is an up-quark? If particles can be created out of nothing, then an up-quark, an example of a fundamental particle, has a finite age. However, if matter cannot be created out of nothing, as the First Law of Thermodynamics states, then matter like the up-quark (and also energy), has always existed and thus even if our Universe had a beginning, it was in the context of a beginning from pre-existing stuff.Read More