Investigating the past

Bill opens a recent piece with this.

On presentism, the present alone exists, and not in the trivial sense that the present alone exists at present, but in the substantive sense that the present alone exists simpliciter.  But if so, then the past is nothing, a realm of sheer nonbeing. But surely the past is not nothing: it happened, and is in some sense 'there' to be investigated by historians and archeologists and paleontologists.  

This extract expresses a key conviction that seems to drive Bill's antipresentism.  Another is the truthmaker objection.  We might squabble over whether the past is nothing or not, but we can certainly agree that it happened.  But is it in any sense 'there' to be investigated?  I don't think it is.  If it were there then history, archeology, and paleontology would not be the difficult disciplines they are.  History would be like journalism.  We would simply go and look to find out about the past.   If there were truth-makers in the present for truths about the past we could just read off those truths from their makers.   But it's not that easy.  Rather,  history, etc, investigate the vestiges (from vestigium, footprint or track) of the past such as documents, artifacts, and fossils that have come down to us.  These are things that existed in the past and still exist in the present, so they are not yet wholly past.  The objective of these disciplines is to construct in the imagination a narrative that's consistent with these vestigia and their reaching us and with nomological truths, and which accounts for them.  Such a narrative may well contain truths but we cannot be sure.  We can't acquaint ourselves with the wholly past.

More recently still he writes,

What ceases to exist becomes nothing. Boston's Scollay Square, which is wholly past, is not nothing.  One can refer to it; there are true statements about it; some have veridical memories of it; there are videos of interviews of people who frequented it; it is an object of ongoing historical research. To dilate a bit on the fifth point:

One cannot learn more and more about what is no longer (temporally) present if it is nothing at all. Only what exists can be studied and its properties ascertained.  But we do learn more and more about Scollay Square. So it must be some definite item.  But, pace Meinong, there are no nonexistent items. Therefore, Scollay Square exists non-presently.  Therefore, what ceases to be present, does not cease to exist. It exists despite being past. It exists tenselessly at times earlier than the present time.  The mere passage of time did not annihilate Scollay Square.

Bill writes as if he takes our ability to refer to Scollay Square, make true statements about it, have veridical memories of it, and so on, to be inconsistent with its being nothing.  I'm afraid I cannot see why the state of Scollay Square has any impact at all on these abilities.  But perhaps Bill would say that his use of 'exists' and 'is' in these paragraphs is tenseless.  He is rarely explicit on this but the appearance of the phrase 'is (not) nothing' is often a clue that one needs to be wary.
But it's debatable that we do learn more and more about Scollay Square.  There's a limited number of vestiges of the square either discovered or yet to be discovered.  All we can do is make more inferences from this evidence and we have no way of knowing if we have arrived at the truth.   And what does Bill mean by 'there are no non-existent items'?  If an 'item' is, loosely, anything we can have an idea of, be it past, future, fictional, merely possible, etc, then there are plenty of items that do no exist. 

Finally, today,

Our penal practices presuppose the reality of the past. But how can presentism uphold the reality of the past?  The past is factual, not fictional; actual, not merely possible; something, not nothing.

The past is an object of historical investigation: we learn more and more about it.  Historical research is discovery, not invention.  We adjust our thinking about the past by what we discover. It is presupposed that what happened in the past is absolutely independent of our present thinking about it.

In sum, historical research presupposes the reality of the past. If there is a tenable presentism, then it must be able to accommodate the reality of the past.  I'd like to know how.  If only the present exists, then the past does not exist, in which case it is nothing, whence it follows that it is no object of investigation. But it is an object of investigation, ergo, etc.

I just don't understand why Bill will speak of (items of) the past in the present tense. Unless he is conflating things of the past with our present ideas of them.  Our idea of Caesar is derived from fact, not fiction.  Somebody was acquainted with Caesar and wrote about him, including Caesar himself! Likewise the characteristics we attribute to Caesar were actualised in Caesar; they did not remain a mere sketch of a Roman general and emperor.  And Caesar was of course something, once, not nothing, always.  I don't see why the past---the things and events now past---cannot be objects of investigation despite their now being nothing.  History is the formulation and revision of our ideas about the past, subject to the constraints imposed by the present vestiges of the past.